process to depressurize a nuclear power plant, depressurization system for a nuclear power plant and

专利摘要:
PROCESS TO DEPRESSURIZE A NUCLEAR PLANT, DEPRESSURE SYSTEM FOR A NUCLEAR PLANT AND CORRESPONDING NUCLEAR PLANT. The present invention relates to a process a to the respective system for the depressurization of a nuclear power plant (2), with a containment sphere (4) for the retention of activity carriers and with an outlet (10, 10 ') for a depressurization flow, where a depressurization line (12, 12 ') with a filtration system is conducted out of the containment sphere (4) into the atmosphere, where the filtration system comprises a filtration chamber (16) with an inlet of the filtration chamber (124), an outlet of the filtration chamber (128) and a sorbent filter (18) between the two, and where the depressurization flow is first conducted to a high pressure section (70), then it is relaxed by expansion in a choke device (72), then it is conducted at least partially, through the filtration chamber (16) with the sorbent filter (18) and finally released into the atmosphere. In order to enable an especially efficient and effective retention of carriers of activities contained in the depressurization flow, in particular organic compounds containing iodine, it is provided, according to the present invention, that the relaxed depressurization flow (...) .
公开号:BR112013004332B1
申请号:R112013004332-6
申请日:2011-07-18
公开日:2021-01-26
发明作者:Bernd Eckardt；Norbert Losch；Carsten Pasler
申请人:Framatome Gmbh；
IPC主号:

专利说明:

[0001] - primeiro é conduzido em uma seção de alta pressão, - em seguida é relaxado por meio de expansão em um dispositivo de estrangulamento, - em seguida, pelo menos parcialmente, atravessa a câmara de filtração com o filtro de sorvente, e, - finalmente é soprado para a atmosfera. [0001] The present invention relates to a process for depressurizing a nuclear power plant with a containment sphere to contain the carriers of activity and with an outlet for a flow of depressurization, the flow of which is depressurized through a depressurization line equipped with a filtration system out of the containment sphere into the atmosphere, the filtration system comprising a filtration chamber with a filtration chamber inlet, a filtration chamber outlet and a sorbent filter between the two, and the flow of depressurization: - first it is conducted in a high pressure section, - then it is relaxed by means of expansion in a choke device, - then, at least partially, go through the filtration chamber with the sorbent filter, and, - it is finally blown into the atmosphere.
[0002] - a linha de despressurização compreende uma seção de alta pressão; - no final da seção de alta pressão um dispositivo de estrangulamento é conectado à linha de despressurização; - a linha de despressurização a jusante do dispositivo de estrangulamento desemboca na entrada de câmara de filtração; e, - a saída de câmara de filtração é ligada a uma abertura de escape que leva para a atmosfera. [0002] The present invention also relates to a corresponding depressurization system for a nuclear power plant with a containment sphere to contain activity carriers and an outlet for a depressurization flow, with an equipped depressurization line connected to the outlet. with a filtration system, the filtration system having a filtration chamber with a filtration chamber inlet, a filtration chamber outlet and a sorbent filter disposed between the two, and that: - the depressurization line comprises a high pressure section; - at the end of the high pressure section, a choke device is connected to the depressurization line; - the depressurization line downstream of the throttling device opens at the entrance of the filtration chamber; and, - the filtration chamber outlet is connected to an exhaust opening that leads to the atmosphere.
[0003] [0003] Finally, the present invention relates to a nuclear power plant with such a system of depressurization.
[0004] [0004] For the containment of active gases or vapors that form in malfunctioning states, especially in the unlikely case of core fusion, nuclear power plants are usually surrounded by a relatively massive containment sphere, hermetically sealed against the outside, concrete, reinforced concrete or steel, also called "containment". Usually, such containment housings are designed to withstand high internal pressures as well, as they can occur, for example, in a de-toning gas explosion or massive vapor release of refrigeration medium from the refrigerant circuit.
[0005] [0005] However, research on the behavior of containment under considerably higher accident pressures has shown that in unfavorable situations, due to the permeability points that arise. Possibly, a relevant release of a highly contaminated atmosphere into the environment may occur. In order to minimize such unfiltered leaks, it is very advantageous that a wide pressure relief can be carried out up to small excess pressure or even to the ambient pressure. This is extremely important especially in the case of containment for which in these phases of excess pressure a crack formation due to construction is more likely, for example, in concrete containment or in sensitive sealing areas, such as locks etc..
[0006] [0006] For this reason, in numerous nuclear power plants different systems are already installed for limiting excess pressure and relieving (filtered) pressure from the containment in accident situations. These devices make it possible to retain aerosols and partially also elemental iodine. Effective organoiodine retention of this depressurization flow - in passive operation without foreign power supply - is not possible up to the present date. More recent discoveries in the accident survey show, however, that in such events in particular the fraction of organoiodide emitted can contribute essentially to the radiation load of the population, being, therefore, relevant to the risk. Organoiodine in the sense of the present application is in particular iodine in the form of low carbon organic compounds, such as methylene iodide etc.
[0007] [0007] For example, in the process initially mentioned according to the international document WO 90/16071 and the respective device, a flow of depressurization that leaves the containment sphere through a line of depressurization, under a relatively high pressure, after the its relief and drying of expansion, is conducted through a choke device, also called a choke, through a filtration chamber with a sorbent filter. Such sorbent filters are also called molecular sieves or, for short, mol sieves, and retain elemental iodine relatively well in the depressurization flow by means of sorption when operating conditions are selected in such a way that there is no condensation of the flow separation. of depressurization in the molecular sieve. In wet operation, however, irreversible destruction or "clogging" of sensitive filtration surfaces can occur.
[0008] [0008] In order to avoid this, according to WO 90/16071, a sufficiently high operating temperature of the iodine sorption filter, especially with a silver nitrate layer is safeguarded by the fact that the relatively low pressure flow hot in the high pressure section, that is, upstream of the throttling device, is conducted by passing the filtration chamber (or also through heating tubes through various filtration elements), preheating these by means of heat transmission . The device can be combined with coarse and fine filtration connected in series, a metal fiber sieve for dehumidifying the gas, and in addition with a Venturi washer blowing freely. The dew point distance obtained from the depressurization flow in the low pressure section is essentially determined by the (theoretical) choke temperature, and in this case it is only about 5 ° C conditioned by the construction. Organoiodine retention, as already mentioned above, according to recent research is not satisfactory, at least not with an economically viable mode of operation without the use of foreign energy.
[0009] [0009] In addition, especially in shutdown phases (no flow) due to the decomposition of stored activities, considerable amounts of later heat occur. This can cause a relevant heating of the molecular sieve, since with an operating temperature of about 210 ° C a melting of the micro-crystals occurs due to the melting of the silver nitrate layer and, thus, the separation effect is lost and an activity release occurs.
[0010] [00010] The process of reducing pressure in the containment sphere through the (filtered) discharge of gas or steam under excess pressure into the atmosphere is also called "ventilation." Accordingly, the flow of depressurization is also called of ventilation gas flow.
[0011] [00011] In the project and in the possible releases of activity the plants currently operated and the new reactors of the third generation (GEN 3) are clearly different, since in the last ones the core merger has already been taken into account in the project. Devices that have already been retrofitted, such as, for example, washers or sandbed filter combinations, do not solve the new problem to be assessed regarding the retention of organoiodine and the wide depressurization desired in itself, especially because of the high activation pressures required in scrubbers and small reaction surfaces for the exchange of matter in the liquid phase and the very small separation action for iodine in sand beds or molecular sieves in wet operation. An improvement of these devices, also in existing plants, is of essential importance in order to reach the highest safety standards of these nuclear plants.
[0012] [00012] A quantitative separation of all aerosol and iodine activities carried by the air would also enable an essential cost reduction in GEN 3 plants, since the noble gas activities that cannot be retained are decomposed in the day range, thus enabling a medium term depressurization - with no relevant releases. This allows for a simplified design of the containment and the associated security systems and in the matter of considerable cost reductions.
[0013] [00013] Therefore, the present invention has the task of indicating a process for the depressurization of a nuclear power plant of the type previously mentioned that is prepared for an especially efficient and effective retention of carriers of activity contained in the flow of depressurization, in particular of compounds iodine-containing organics. It is also intended to indicate a depressurization system for a nuclear power plant especially suitable for the execution of the process.
[0014] [00014] With respect to the process, this task is solved according to the invention by the fact that the flow of depressurization, relaxed by the choke device immediately before entering the filtration chamber, is conducted through an overheating section, where it is heated by direct or indirect heat transfer from the depressurization flow not yet relaxed in the high pressure section to a temperature that is at least 10 ° C, preferably 20 ° C to 50 ° C above the existing dew point temperature .
[0015] [00015] Surprisingly, it was evident that the strong activity of a gas flow in the depressurization of a safety containment can be retained with high efficiency through a superheat of passive regenerative gas especially effective, connected in series with the throttling device, for example. heat transfer medium from the excess pressure section to the atmospheric section and a subsequent sorbent filtration. As will be explained in more detail below, the overheating of the relaxed depressurization flow in the low pressure section can occur, on the one hand, through a direct heat transfer from the high pressure section of the depressurization line with the ventilation gas as a carrier of the heating heat (first major variation: "dry" heating). On the other hand, an indirect, multi-stage heat transfer can take place via a wet filter / washer fluid circuit connected to the flow in the high pressure section with the wash liquid as an intermediate heat carrier. , which, on the one hand, is heated in the washing vessel by the ventilation gas, (second main variation: "liquid" heating). Both variations can also be combined with each other.
[0016] [00016] The choke device, also called a choke valve or expansion valve, provides a first drying of the flow of depressurization by expansion, and the theoretical choke temperature can also be strongly exceeded due to still existing gas humidity and a non-ideal bottleneck, depending on the stage of the operation. In the superheat section connected after the throttling device there is then - largely independent of the effectiveness of expansion drying - the decisive overheating of the depressurization flow through which a condensation separation in the area of the sensitive iodine sorption filter is safely prevented. humidity, also in unfavorable operating conditions.
[0017] [00017] Through the effective use of the excess heat present in the high pressure area of the depressurization line for the preheating of the filtration chamber, on the one hand, and for the direct heating of the depressurization flow immediately before it enters the filtration chamber, on the other hand, can be dispensed, according to the principle of regenerative heat recovery with heating by its own means, the use of foreign energy, for example, in the form of electric heaters. In this way, the process is not only highly effective, but also especially energy efficient.
[0018] [00018] Advantageously, the flow of depressurization in the superheat section is heated to a temperature that - in supposedly designed fault conditions - is at least 10 ° C, preferably 20 ° C to 50 ° C above the dew point temperature there reigning. Dew point or dew point temperature is that temperature where in the depressurization flow a state of equilibrium of condensation water and evaporated water appears, in other words, the formation of condensate is just beginning. As was surprisingly evident, with a dew point distance of> 10 ° C, preferably> 20 ° C, also with a depressurization flow only partially washed, strongly containing steam, the degree of organoiodide separation, especially in the case of the use of non-water-soluble silver layers, it increases abruptly and reaches, for example, with such sorbent materials based on zeolite, typically values of up to 99.99%.
[0019] [00019] In fact, it would be sufficient for a highly efficient molecular sieve with a silver nitrate layer (soluble in water) to also have a lower superheat of, for example, 5 ° C above the dew point for an effective organoiodine retention with high retention rates. However, it was evident that such a process in plants known to the state of the art depends strongly on reaching the theoretical strangulation temperature and on avoiding any residual moisture content in the gas that severely decrease overheating. Taking into account this new knowledge, such a plant with a conventional construction type, as it is known, for example, from the document WO 90/16071 initially mentioned, cannot be operated effectively and safely with the imminent low overheating. Here, the concept according to the present invention provides an effective solution.
[0020] [00020] Preferably, the excess temperature increase of at least 20 ° C, especially preferred, at least 50 ° C above the dew point temperature, is achieved in the full-load operation of the depressurization system. This means the initial depressurization operation after a malfunction according to the project, when the pressure inside the containment is the highest, and typically - depending on the type of reactor and containment - it is about 3 to 8 bar . In this, mass flow rates of ventilation gas of about 3 to 10 kg / s are achieved. The dew point temperature in the area of the sorbent filter is then typically, depending on the vapor content about 80 to 100 ° C, so that the temperature of the ventilation gas after the superheat carried out at the entrance to the sorbent filter, is preferably about 100 to 170 ° C. In half load operation, when the mass flow rates of ventilation gas are about 25% of the corresponding values in full load operation, the temperature increase is preferably still 10 ° C.
[0021] [00021] Iodine sorption filtration with sliding superheating and inverse residence times (short residence time with great overheating and long residence times with less overheating) can be operated in an especially effective and compact manner up to almost atmospheric pressure - without auxiliary power. In this case, in the event of high pressure in the containment, after the throttling a high volume flow is generated and despite the short residence times resulting in the sorbent filter, due to the high overheating of the gas now in the sorbent, optimal reaction conditions are achieved when while having a high diffusion. With a lower containment pressure, for example, a quarter of the maximum initial pressure of, for example, 500 KPa (5 bar) absolute, a small volume flow with gas overheating is generated after the throttling to almost atmospheric pressure reduced, but due to the permanence time in the now larger sorbent filter, about four times, despite unfavorable sorption conditions, effective iodine sorption is also possible. Effective sorbent filtration is thus possible, even up to total depressurization and with containment temperatures of only 50 ° C to 100 ° C, due to the now increasing residence time in the sorbent filter.
[0022] [00022] In a first major variation of the process, the flow of depressurization in the high pressure section passes at least partially along the filtration chamber, where it is heated by means of an almost direct heat transfer of gas of hot ("dry") ventilation. This means, with regard to equipment, that the high pressure section of the depressurization line, at least in a partial section, is conducted off the filtration chamber and is thermally coupled to the filtration chamber through heat exchange surfaces, so that the filtration chamber is heated by means of the relatively hot depressurization flow in the high pressure section.
[0023] [00023] In an especially preferred embodiment, the flow of depressurization in the high pressure section, before passing through the filtration chamber, is conducted through a washing container ("Lavadof) containing washing liquid, preferably with Venturi washer type inlet nozzles Regarding equipment it does not mean that the wash container is connected upstream of the filtration chamber involved by the depressurization flow in the high pressure section of the depressurization line The wash container produces fine filtration effectiveness of the aerosols contained in the depressurization flow, preferably with an efficiency of> 99%, in order to reduce the aerosol concentration up to a few g / m3 which in a case of malfunction typically reigns in the containment sphere for a range non-critical, for example, few mg / m3 Due to the effective wet filtration of aerosols, relevant deposits on the heat exchange surfaces connected in series are avoided flow in the direction of flow. In this way, it is possible to guarantee an effective and constantly high heat transfer for the overheating of the relaxed depressurization flow in the choke device and for the heating of the sorbent filter.
[0024] [00024] The inlet nozzles through which the depressurization flow enters the washing container, work preferentially in this, according to the principle of Venturi-type injection. The gas flow that passes through a narrowing point (throat) of a jet tube, carries with it washing liquid that is found in the surrounding washing container, through an inlet opening arranged at the point of narrowing, for example, executed as an annular slit, so that an especially intensive mixture takes place between the gas flow and the droplets of washing liquid aspirated or dragged, according to a very fine nebulization. Thereby, aerosol particles and other particles entrained in the gas flow are deposited in the droplets of the washing liquid. After exiting the nozzle, the washing liquid and the gas flow separate again, mainly due to the effect of the gravity force, and the gas flow thus purified and free of aerosols exits the washing container through a line of corresponding gas outlet leading to the heat exchanger and sorbent filter unit connected afterwards. For this purpose, the gas outlet line is properly connected to the washing container above the so-called pool area, that is, above the level of the washing liquid present in the operation and above the ejection and separation zone.
[0025] [00025] It is logical that as an alternative or additionally, common inlet nozzles can also be provided, directed or submerged in the washing liquid. In addition, appropriate flow aids, swirl makers, mixers, agitators and the like may be provided in the area of the wash container pool that increase the boundary surface or internal surface relevant to the (temporary) mixture of ventilation gas and liquid. wash between the two.
[0026] [00026] Preferably, the inlet nozzles and the depressurization flow line above the inlet nozzles are so configured and dimensioned that the depressurization flow is directed into the washing container with a flow rate above 100 m / s through the inlet nozzles. In the case of high-speed Venturi separation, these speeds need to be reached especially in the narrows or throats of the Venturi tubes where the inlet openings for the washing liquid are located.
[0027] [00027] Advantageously, the washing liquid in the washing container is chemically conditioned by the addition of bleach, preferably caustic soda bleach and / or sodium thiosulfate, preferably as an aqueous solution of sodium thiosulfate. In this way, a relevant increase in the retention of activities contained in the flow of ventilation gas is obtained, primarily of elemental iodine. For this purpose, corresponding dosing devices and injectors are attached to the washing container, through which other chemical agents may also be added.
[0028] [00028] Advantageously, a surface reaction accelerator is also mixed with the washing liquid, especially in the form of amino, which promotes the deposition / attachment of the aerosols entrained in the ventilation gas flow to the washing liquid.
[0029] [00029] Between the washing container and the heat exchanger and sorbent filter unit, other filtration elements can be connected to the high pressure section of the depressurization line, in particular metal fiber or candle filters, which are effective as fine filters. in order to further reduce the aerosol content in the depressurization flow before passing through the heat exchange surfaces. Such filtration elements can also be constructively integrated into the wash container and are preferably arranged above the pool area. If these filters are designed for dry operation (preferred), liquid separators or separators for dehumidifying the gas flow are suitably connected in series.
[0030] [00030] In an alternative variation of the process, the flow of depressurization is removed from a condensation chamber of a reactor, especially from a reactor to boiling water, and from there, it is conducted, without the intercalation of a washing container (external ), off the filtration chamber and / or the superheat section for heating. This means for equipment that the depressurization line on the inlet side is connected to the condensation chamber.
[0031] [00031] A condensation chamber, in this context, is usually a partial space, partially filled with liquid (condensate), separated through a gas-tight separation wall from the internal space of the containment (the so-called pressure chamber), the a condensation chamber which, through a overflow tube, called a condensation tube, submerged in the liquid is connected to the remaining internal space of the containment. In this, in the normal operation of the nuclear reactor, the overflow tube is closed by a safety plug. In the event of a malfunction with worthy mention of steam and non-condensable gases and the respective pressure generation in the pressure chamber, the gas / steam mixture can enter the condensation chamber through the overflow tube, the vapor content being condenses for the most part. The non-condensed fractions accumulate above the liquid level in the condensation chamber and, according to the variation described here of the present invention, are conducted out of the condensation chamber and the containment sphere as a depressurization flow through the line of depressurization.
[0032] [00032] The term "condensation chamber", in the present context, should also include other condensation pools with similar operation, for example, condensation chute systems of a VVER type reactor (water-water-energy-reactors) type of Russian or other construction.
[0033] [00033] Since the condensation chamber in a certain way has a washing machine or aerosol filter effect for the depressurization flow, therefore, in a preferred embodiment, a separate washing container disposed outside the containment of the type described above.
[0034] [00034] The arrangement of the regenerative heat exchanger that constitutes the superheat section and the filtration chamber with the sorbent filter, in order to have a good heat transfer, is preferably in direct proximity with distances of <5 m or , properly integrated within a component. In this, the combination can be arranged inside a pressurized container in several chambers, in order to reduce heat and expenditure losses and to safeguard the best conditions of overheating and reaction.
[0035] [00035] Preferably, in the first aforementioned variation of the process, the sorbent filter is arranged in an annular chamber that surrounds the central chamber with gas heating already integrated through the heat exchanger tubes. The annular chamber has, for example, sieves of plate tube perforated with the sorbent agent. A sorbent scraping retention by means of a fiber filter can be connected after the sorbent filter. As an alternative, it can be envisaged to build a flat filter chamber largely without pressure with interchangeable regenerative heat exchange elements. In this, a modular construction is possible with the joining of several modules. The heating of the sorption unit, in this case, is done immediately before the passage; advantageously, the filtration chambers are still partially heated outside the medium.
[0036] [00036] In an especially advantageous embodiment, the depressurization flow is conducted at least partially through a central chamber that is surrounded by or adjacent to the filtration chamber, the depressurization flow being compressed relatively strongly in the high pressure PE section conducted through heat exchanger elements arranged in the central chamber or projecting into it, especially heat exchanger tubes, and the relaxed depressurization flow, with a relatively large volume in the superheat section, is conducted passing externally off the heat exchanger elements through the central chamber. This means, the hot depressurization flow that flows upwards after the choke device is still under high pressure (possibly also only a partial flow of it) transfers an essential part of its heat to the already relaxed, conducted depressurization flow. along the heat exchanger tubes, and thus indirectly also to the filtration chamber located more externally for the preheating of the sorbent filtration elements.
[0037] [00037] Regarding the equipment this means that the filtration chamber appropriately surrounds or is adjacent to a central chamber, with one or more heat exchange elements that can be crossed by the flow are arranged in the central chamber or are designed to inside it, and the flow conduction in the depressurization line is configured in such a way that the flow of depressurization in the high pressure section is conducted through the heat exchanger elements and in the superheat section it is conducted on the external side, passing to the away from the heat exchange elements through the central chamber. Appropriately, in this case, one or more openings are provided between the central chamber and the filtration chamber that form the inlet of the filtration chamber.
[0038] [00038] For a heat transfer, the heat exchanger elements are especially effective, preferably they are executed as heat exchanger tubes and appropriately and on their external side they present ribs or protuberances that are distributed in regular, perimeter distances or extend in longitudinal direction. Also on the internal side of the heat exchanger tubes, the respective structures or embedded parts can be provided to generate turbulence or to form a whirlpool current.
[0039] [00039] Advantageously, the flow of depressurization in the superheat section is conducted in countercurrent or crosscurrent in relation to the flow of depressurization in the high pressure section. With regard to equipment, this means, for example, that the heat exchanger tubes that make up the superheat section are arranged in the central chamber or project into it with the respective orientation, for example, as essentially vertical tubes or as curved tubes in the form of a zigzag.
[0040] [00040] Due to the realization of the heating surfaces as smooth surfaces that repel dirt with coatings resistant to radiation or smooth surfaces of stainless steel or additionally benefited, such as, polished, electro-polished, and the integration of condensate distribution systems in the area of heat exchange, such as, for example, floor or rail systems and / or spray system, effective heat transfer is permanently supported effectively.
[0041] [00041] For even more intensive preheating, using an additional heat transfer device (tubes or annular chamber), a partial flow of the high pressure depressurization flow can be removed from the depressurization line, especially even before the wash container and be taken for heating directly through the sorbent filter or to a connected area in front of it within the flow direction. In this way, it will be possible, especially in situations with a clearly overheated containment atmosphere, to achieve a further increase in operating temperatures in the sorbent and to further improve organoiodine retention.
[0042] [00042] Advantageously, a flow rate of the depressurization flow in the range of 10 m / s to 50 m / s is regulated in the high pressure section. In the superheat section, a flow rate of the depressurization flow is regulated in the area from 10 m / s to 70 m / s. The free flow diameter of the throttling device is appropriately regulated in such a way that the pressure in the high pressure section is two to five times the pressure in the superheat section. Especially, in the presence of a washer (Venturi) in the high pressure section, the humid filtration of the depressurization flow that happens there with a pressure of about 7 to 1 bar, is preferably performed with two and five times the pressure of the molecular sieve in the sorbent filter that is approximately at atmospheric pressure.
[0043] [00043] As already mentioned above, the aerosol-containing ventilation gas is conducted in the high pressure section with advantage through the heat exchanger tubes that are favorably arranged in a channel-type compartment (central chamber), for the generation of high speeds of gas, especially> 10 m / s. Heat transfer elements (fins) on the side of the crude gas are preferably carried out with a distance of> 1 mm, especially preferred, of> 5 mm, and predominantly vertically oriented. By selecting a respectively oversized transfer surface on the aerosol gas side, with an additional heating surface reserve of> 100%, especially robust and reliable operation are> 500% (related to the value without fouling), it can be safe operation is guaranteed. In the heat exchanger unit, partial filtration of aerosols and iodine may continue to occur in a directed manner.
[0044] [00044] The gas conduction of aerosol-containing gases through the heat exchanger tubes is made possible in an execution as a smooth tube heat exchanger and especially high flow rates of, for example,> 10 m / s up to 50 m / s, so that relevant deposits on the tubes can be avoided. On the relaxed, atmospheric side, at maximum flow stages, very high gas velocities from> 10 m / s to 70 m / s are also regulated, so that high heat transfer values and very compact components are achieved.
[0045] [00045] A high-speed regenerative heat recovery can preferably be implemented in a heat exchanger design according to the countercurrent and crosscurrent principle, such as a fin tube or plate heat exchanger. In order to achieve an effective heat transfer in cases with small flow, they are provided inside and outside the tubes, to generate turbulent and / or twisted flow conditions, preferably inserts or structured tube surfaces (ribs, etc.). This makes it possible to achieve a return heat number of> 0.5 with very compact units with a high containment pressure and flow rate, which can then be increased to up to 0.8 with a low containment pressure and low flow.
[0046] [00046] Appropriately, the central chamber of the heat exchanger and absorbent filter unit is connected in the bottom area to a condensate collecting basin for the condensate that forms during the operation. By injecting or adding sodium hydroxide or caustic soda bleach (NaOH) and / or sodium thiosulfate (Na2S2O3) and / or calcium peroxide (CaO2) to the condensate, for example, in the area of the condensate collecting basin , or by injecting into the central chamber, a relevant increase in the separation of iodine can also occur in the low pressure section of the regenerative heat exchanger. In addition, filtration or retention of chlorine-containing gases can thus be favored.
[0047] [00047] In an especially preferred embodiment of the depressurization system, a pre-filter (dry filter) for coarse aerosol filtration of the depressurization flow is disposed within the containment sphere, as an alternative or additionally also outside the containment sphere. Advantageously, a bypass line that can be closed with an adjustable valve is connected parallel to the pre-filter, so that the flow of depressurization conducted according to demand, partially or completely passing through the pre-filter, out of the containment sphere to the filtration systems on the outside.
[0048] [00048] In the ventilation of the containment sphere, the gas flow strongly containing activities can then be directed through the pre-filter, where, for example, by means of metallic deep-bed filtration cores or metallic fiber filters, a wide range occurs filtration of coarse aerosols with diameters of> 1 µm (retention rate preferably> 90%) and partial filtration of fine aerosol fractions that are small in quantity with diameters of> 1 pm (retention rate preferably> 50%). The preliminary filtration is preferably done with two to five times the pressure in the sorbent filter (molecular sieve), in the pressure range of, for example, 700 to 100 KPa (7 to 1 bar).
[0049] [00049] In order to limit the possible pressure losses in the pre-filter and especially in the case of the existence of a washer (Venturi) connected later, in the inlet nozzles, for example, Venturi nozzles, to be able to regulate relatively high inlet speeds, depending on demand, a bypass operation is planned, passing by the pre-filter. The opening of the bypass preferably occurs automatically and passively (that is, without the use of foreign energy), through the integration of an excess pressure limiting device, such as, for example, a rupture disc or a pressure relief device. spring-loaded overflow valve. The opening mechanism can be adjusted in such a way, for example, that the bypass line is released when the pressure loss in the pre-filter exceeds a value of> 50 KPa (0.5 bar). Due to the retention provided with the bypass line closed by pre-filtering the largest amount of aerosols in the initial high concentration phase of the accident, in the later phase of the accident, with the bypass line open, an effective operation can be made possible regenerative heat exchanger device - also without pre-filter.
[0050] [00050] With advantage the relevant plant components are dimensioned in such a way and the operational parameters in the pressure relief operation are selected in such a way that the pressure loss caused by the existing pre-filter and the regenerative heat exchanger in the section high pressure in all is <30% of the total pressure loss available until release into the atmosphere, in order to guarantee a high temperature level for regenerative heating.
[0051] [00051] In an advantageous variation, an additional heating device is provided, especially an electric heating device or a heating device operated with steam from the process of another installation to heat the depressurization flow in the depressurization line, which can properly be regulated independently of the operating conditions in the regenerative heat exchanger and in the superheat section. This heating device can be arranged, for example, downstream of the choke device. As an alternative or additionally, such heating elements can also be arranged upstream of the choke device in the high pressure section of the depressurization line. Advantageous is, for example, an arrangement in the washing container (if any), for example, in the washing liquid pool or below it, for example, in the ejection zone or in the area of additional separators / filters, if any.
[0052] [00052] Such additional heating of the depressurization flow can also be provided by a second thermal accumulator previously heated by means of the depressurization flow or by means of auxiliary energy sources. These devices can also be used to bridge the starting operation.
[0053] [00053] In another useful variation, a gas dryer or a drying radiator is connected to the depressurization line between the throttling device and the overheating section, which provides additional drying and lowering of the dew point before entering it. overheating section. The cooling performance of such a drying radiator is appropriately <25% of the cooling performance of the regenerative heat exchanger, preferably <10%.
[0054] [00054] Thus, in cases of operation where the containment pressure is already low and temperatures are already low, that is, with only a small overheating potential, such as, for example, also at startup, in the cooling device interconnected, the dew point is lowered through partial condensation and release of heat to the environment or also to the masses to be heated with the respective heat capacity. In the next superheat section, a clear distance from the dew point can now be regulated by heating the depressurization flow to almost the operating temperature with high pressure.
[0055] [00055] In addition, between the strangulation device and the sorbent filter, a (additional) washing device can be connected to the depressurization line, which is designed to contain chlorine and / or nitrous gases so that that the depressurization flow, after being relaxed, is purified in the choke device and before passing through the sorbent filter in the washing device.
[0056] [00056] In an advantageous embodiment, an aspirating fan with an electric motor or internal combustion engine is connected or can be connected, if necessary, in the depressurization line, so that, especially in long-term operation of the depressurization system , that is, when the internal pressure of the initial containment, reigning after a malfunction, is already greatly reduced, the flow of depressurization is sucked "actively" by the aspirating fan out of the containment sphere through the line of depressurization with the filtration elements contained therein. In other words, through the connection of an aspirating fan, the filtration system, in operation after long-term damage, can still be actively operated or also be used in a targeted manner for the maintenance of low pressure in the containment, in order to thus completely avoid unfiltered external leakage from the containment.
[0057] [00057] With the help of the aforementioned measures, especially the drying of the gas and the distance from the dew point thus achieved, a relevant occupation of the large internal reaction surface of the water sorbent filter containing water, both now and safely, can be avoided. in the area of macropores and micropores of the sorption agent, and thus, the retention of iodine by absorption on surfaces and eventually chemisection can become especially effective.
[0058] [00058] In an advantageous embodiment, especially in the case of the presence of wet filtration in the high pressure section by a corresponding washing device, a bypass line is connected to the depressurization line to bypass the filtration chamber.
[0059] [00059] In this, appropriately the percentage of the depressurization flow that flows through the bypass line can be regulated with the help of suitable adjustment means. In this way, a mode of operation of the depressurization system becomes possible, where a partial (adjustable) flow of the depressurization flow is blown out directly into the atmosphere through the bypass line, bypassing the filtration chamber and the disposable sorbent filter. in it. To adjust the pressure, a suitable pressure reduction valve is connected to the bypass line.
[0060] [00060] Thus, with very large flow rates, for example, in initial phrases of accidents with large amounts of gas and little occurrence of organoiodine and wide separation of the elemental iodine that is dominant at this stage in the washing device connected at the front, it can occur an effective retention of total activities, without the iodine sorbent filter having to be ordered in excess. In later phases - with the formation of a relevant organoiodine that started in the meantime and now relatively little gas occurrence - then it happens with advantage with the bypass line widely or completely closed, the filtration of the complete flow under the inclusion of the iodine sorbent filter, the in order to continue to ensure high retention of all activities.
[0061] [00061] The sorbent materials or sorbent agents are preferably made with> 50 m2 / g of internal surface and inorganic materials. Through the superheat process that now acts permanently, even the use of sorbent materials with layers of silver nitrate sensitive to moisture (soluble in water) or doping is possible.
[0062] [00062] For example, the use of ceramic products, impregnated with silver, for example, silica gel, makes it possible to permanently obtain a very efficient iodine separation of> 99.9%. The molecular sieve, for example, can also be produced on the basis of zeolite or with another carrier body, preferably inorganic and be covered or doped with silver nitrate (AgNO3) which, in the occurrence of iodine, is transformed, for example, into iodide of silver. However, this is only advantageous when sufficient overheating of the depressurization flow can be guaranteed in all operational phases. In this, organoiodine retention can also be advantageous with high efficiency in polluted gases, for example, nitrogen-containing gases and the like.
[0063] [00063] As a more robust filtration material, an artificial zeolite can be used, for example, through the exchange of ions, silver and / or heavy metal cations in the three-dimensional crystal grid. Combinations of solvent-free zeolites are also possible, preferably with an open structure. Such a solvent-free molecular sieve, for example, of the faujasite structure type, is even safer for operation, also in a strongly superheated steam atmosphere of, for example,> 200 ° C and also in conditions of vapor absorption of short-term water (wet operation). A wet operation of short duration, therefore, does not cause the destruction of these zeolites, for example, doped with silver. In the same way, a small amount of bleach can be tolerated. In addition, short-term overheating (additional) is achieved by absorbing moisture.
[0064] [00064] The sorbent filter preferably comprises a zeolite-based sorbent material as a mixture of zeolites with non-water-soluble doping, especially a doping of silver and inorganic sorbent materials with water-soluble doping, for example, a doping of silver nitrate. In this, with advantage, also in short wet phases, the adsorption of water vapor occurs exclusively or primarily in the zeolite, and the release of adsorption heat that occurs temporarily promotes the process, so that a separation of substances soluble in water, such as, for example, silver nitrate, can now be safely avoided. This combination as a mixture of, for example, both zeolites with a doping of silver as well as a molecular sieve with a doping of silver nitrate and / or also housed in a common carrier body has proved to be highly efficient and safe in operation due to the mechanisms dual separation.
[0065] [00065] In addition, phosphazene molecules, phosphazene zeolites, especially cyclo-triphosphazine zeolites, channel-type crystals, possibly with additional doping, can be used as appropriate sorbent materials for especially effective and economical retention of iodine.
[0066] [00066] In a preferred embodiment, the filtration chamber may contain, in addition to the iodine sorbent filter, also other filtration devices and retention devices, for example, for the retention of gases containing chlorine and / or nitrous gases and / or compounds containing oil. For that purpose, for example, sand bed filters and possibly the injection or feeding of suitable chemical agents.
[0067] [00067] In addition, it can be achieved, in this case, in certain phases of the operation by means of directed partial adsorption of water vapor in the aforementioned zeolites (increases in humidity by, for example, <2% by weight by means of sorption) more an overheating of gas of short duration, and thus, the desired continuous organoiodine retention will be guaranteed. This is especially interesting in the start-up operation (the so-called start-up adsorption). In order to limit temperatures in the event of humidity, a specific limitation of the catalytic activity of these sorbent agents can also be carried out, for example, through diffusion layers or mixed doping (for example, with silver and / or silver cations). heavy metal) and eventually with non-catalytic additions.
[0068] [00068] As already indicated above, with advantage in starting the depressurization system - with operating temperatures still relatively low - at least partial vapor adsorption is allowed in the sorbent filter, and the adsorption heat is used to overheat the depressurization flow and the sorbent filter. This, however, only makes sense when the sorbent filter is sufficiently insensitive to moisture, that is, for example, built on the zeolite base with non-soluble doping.
[0069] [00069] In a second main variation of the process that is built on the basis of the presence of a washing vessel for the wet filtration of the depressurization flow in the high pressure section, the washing liquid of the washing vessel is conducted through a line circulation system that at least in a partial section is in thermal contact with the filtration chamber, heating it by transferring the heat of the washing liquid in circulation. This means, with respect to the equipment, that a circulation line is connected to the washing container for the circulation of washing liquid, the circulation line passing through the filtration chamber, being in thermal contact with it, in a way that a heat transfer occurs from the circulating washing liquid to the filtration chamber.
[0070] [00070] This means, therefore, that the amount of heat entrained by the flow of ventilation gas in the high pressure section of the depressurization line is largely transferred to the washing liquid in the washing container, which amount of heat is then circulates through or outside the filtration chamber, where a new heat transfer takes place to heat the filtration chamber with the sorbent filter and / or to overheat the depressurization flow relaxed by the choke device immediately before its entry in the sorbent filter.
[0071] [00071] It is especially preferred that the flow of depressurization relaxed by the choke device in the superheat section is in thermal contact with the circulation line and is heated through heat transfer by the circulating washing liquid. For this purpose, the overheating section of the depressurization line is thermally coupled to the circulation line through heat exchange surfaces, so that there is a transfer of heat from the circulating washing liquid to the depressurization flow.
[0072] [00072] In a preferred embodiment, the flow of the washing liquid through the circulation line is triggered by the impulse that is transmitted in the washing container by the depressurization flow to the washing liquid. For this purpose, at least one of the inlet nozzles is properly oriented, for example, oriented towards the entrance of the circulation line, so that the impulse transmitted to the washing liquid of the depressurization flow that flows through it activates the circulation. of the washing liquid through the circulation line. But, as an alternative or in addition, suitable motor-driven pumps can also be provided to trigger or support the flow of circulation.
[0073] [00073] Advantageously, the circulation line has a washing liquid inlet that flows into the washing container and a washing liquid outlet situated higher in relation to the washing liquid inlet that also flows into the washing container. In this way, the washing liquid removed from the washing container, after crossing the circulation line, is again taken to the washing container at a geodesically higher point.
[0074] [00074] Preferably the washing liquid is removed from the washing container at a point where the gas bubble content of the depressurization flow is especially high, for example, in the discharge area of the inlet nozzles.
[0075] [00075] In a preferred embodiment, a central chamber is provided that surrounds or is adjacent to the filtration chamber, the circulating washing liquid being conducted through heat transfer elements disposed in the central chamber or projecting inwards. of it, in particular, heat transfer tubes, and the depressurization flow in the superheat section externally is conducted away from the heat transfer elements through the central chamber. The washing liquid flowing through the heat transfer tubes therefore transfers a large part of its heat content to the low voltage depressurization flow that passes outside the tubes which is then superheated before entering the filtration chamber. . In addition, the low pressure depressurization flow thus superheated transfers a small part of its heat content before entering the filtration chamber to the more externally located filtration chamber, which in a way is preheated.
[0076] [00076] It is also advantageous if the low pressure depressurization flow in the central chamber is conducted in countercurrent or crosscurrent in relation to the washing liquid that flows through the heat transfer elements.
[0077] [00077] Furthermore, it is advantageously provided that the flow of depressurization passes through the central chamber in a vertical direction from top to bottom, and the washing liquid with a vertical flow direction from bottom to top through the heat transfer elements.
[0078] [00078] Preferably a flow rate of the washing liquid in the circulation line of more than 1 m / s, preferably above 3 m / s, is regulated so that deposits of the washing liquid can be avoided widely and so that an especially effective heat transfer is achieved.
[0079] [00079] In other words: The washing liquid that serves as the heat carrier is activated by the impulse of the high speed ventilation gas line. The washing liquid, in this case, is removed from the washing container near the vent gas inlet and transported through tubes into the heat exchanger of the heat exchanger and absorbent filter unit and then back to the pool. hurts washing container. Precisely through the directed removal of a liquid mixture more strongly containing ventilation gas (containing bubbles) and driving upwards through the heat exchanger device, the drive is reinforced due to the lower density compared to the density of the washing liquid ( no bubbles) in the wash container pool, especially in the case of the new geodesically higher inlet. By removing in the warmer zone of the washer with air and steam bubbles and by condensing air bubbles during heat transfer the temperature level can be raised even further and the temperature difference in the heat transfer can be minimized further. The return to the washing container preferably occurs above the sedimentation zone.
[0080] [00080] It should also be mentioned that the second main variation also applies without problems, and the explanations given above in the context of the first variation of the process / system regarding the filtration materials and temperature relationships in the filter do not need to be repeated here. sorbent, regarding the pressure ratios and flow velocities in the lines that carry the ventilation gas, regarding the configuration of the washing container and the inlet nozzles disposed therein, and regarding the optional components provided gas dryer, blower, additional filter etc.
[0081] [00081] The first and the second main variation of the process and the corresponding depressurization system can also be combined with each other, and this mainly in the sense that it is possible to heat the filtration chamber with the sorbent filter and / or and the relaxed depressurization flow in the overheating section both directly through the depressurization flow in the high pressure section ("dry") and also indirectly through the washing liquid ("liquid / wet"). For example, the construction may be such that heating at least in certain operational situations occurs simultaneously in both ways (that is, both "dry" as well as "liquid"), in other operating conditions, however, for example, in depending on the filling level of the washing liquid in the washing container, in only one of two ways. In perfecting the concept, means are provided to be able to change in an active and directed way from one way to the other.
[0082] [00082] Precisely in the aforementioned combination of different heating concepts, but also in other cases, the washing container and the heat exchanger and absorbent filter unit, possibly also only parts of them, for example, the heat exchanger, can be constructively joined or integrated into a common component. An example of this will be explained in the detailed description of the figures.
[0083] [00083] With respect to the system, the task initially mentioned is solved with a depressurization system with the characteristics of the invention.
[0084] [00084] According to this it is provided according to the present invention that the depressurization line between the throttling device and the inlet of the filtration chamber has a superheat section that is thermally coupled to the high pressure section through transfer surfaces. of heat, these heat transfer surfaces are dimensioned in such a way that the flow of depressurization that arises in conditions of failure of the project is heated in the superheat section to a temperature that is at least 10 ° C, preferably 20 ° C up to 50 ° C above the dew point temperature prevailing there.
[0085] [00085] Other advantageous achievements of the system have already been described above or result from the description of the respective process steps.
[0086] [00086] The advantages obtained with the present invention are especially that by means of a directed overheating of the depressurization flow before it enters the iodine sorbent filter in the sorbent both in the area of macropores and micropores, a relevant occupation of the reaction surfaces with water vapor and a blockage through capillary condensation. Due to the passive and regenerative performance of the superheat process with heat recovery from the high pressure section, the process can also be used in the event of a complete power failure ("station blackout ') at the nuclear plant to be depressurized. through the superheat of the decisively high gas of> 10 ° C, preferably> 20 ° C, for example, at the temperature level of> 120 ° C to 170 ° C and more (at high flow rates and high gas superheat in the phase of the depressurization process), there is a significant increase in the reaction speeds in the iodine sorbent filter. Through the very high internal reaction surfaces, now practically available without restriction and through better diffusion, it is possible to achieve a sorption filtration of highly effective passive iodine, also for organoiodine compounds, with retention rates of> 97%, preferably> 99%. A resuspension (new release) of the iodine from the sorbent filter and iodine can be largely avoided by chemical bonding of iodine and by permanent heating of the iodine sorbent filter.
[0087] [00087] Through the highly efficient wet filtration of the depressurization flow in the high pressure area, possibly together with other filtration devices, especially a metal pre-filter and / or a dry filter on the sand and gravel bed base, it becomes if possible, for the first time, to release the active gases or vapors that form in damaged states in the containment to the environment in a filtered manner, with an organoiodide retention of> 99% to 99.9% for the ultimate limitation of pressure in the containment. In this also other activities and aerosols carried by the air are safely retained in the filtration system, even with a ventilation operation of several days.
[0088] [00088] Several examples of carrying out the present invention are explained in detail below with the help of drawings. They show respectively in a strongly simplified and schematic presentation:
[0089] [00089] FIG. 1 shows a diagram of the principle of essential components of a depressurization system according to the present invention for a nuclear power plant.
[0090] [00090] FIG. 2 shows a regenerative heat exchanger and absorbent filter unit of the depressurization system according to FIG. 1 in a longitudinal section.
[0091] [00091] FIG. 3 shows a perspective view of several regenerative heat exchanger and absorbent filter units according to FIG. two.
[0092] [00092] FIG. 4 shows an alternative variation of the depressurization system according to FIG. 1.
[0093] [00093] FIG. 5 shows an alternative variation of the combined regenerative heat exchanger and sorbent filter unit according to FIG. 2 with an integrated washing container.
[0094] [00094] Identical parts or with identical effect carry the same references in all figures.
[0095] [00095] Nuclear plant 2 shown in FIG. 1 partly presents an external containment sphere 4, also called containment, with a solid reinforced concrete jacket. The containment sphere 4 involves an internal space 6. In the internal space 6, the essential nuclear components of nuclear plant 2 are arranged, such as the reactor pressure vessel with the reactor core and other nuclear and non-nuclear components of the plant (not shown). The reinforced concrete jacket of the containment sphere 4, on its internal side, is covered with a steel jacket. The containment sphere 4 forms an airtight seal of the internal space 6 against the external environment, and in the case of an unlikely failure with the release of gases or vapors charged with radioactivity to the internal space 6 provides for its retention and inclusion.
[0096] [00096] The containment sphere 4 is designed to also withstand relatively high internal pressures, such as 3 to 8 in the internal space 6, as can occur in failure states with massive vapor release, and at the same time remain watertight for a longer period. Likewise, to further increase the safety of the reactor, and also in order to be able to enter the internal space 6 again after a fault, a depressurization system 8 is provided with the help of the gases and vapors contained in the internal space 6 can be filtered, purified and released into the environment largely without activities, so that a controlled pressure reduction in the internal space is possible 6. The respective process is also called venting.
[0097] [00097] The depressurization system 8, in the present case, is designed for an especially efficient and energetically advantageous retention of carriers of activities contained in the ventilation gas, especially elemental iodine and compounds containing low carbon number organoiodine (the so-called organoiodine). For this purpose, the depressurization system 8 comprises a depressurization line 12, connected to an outlet 10 or to a passage in the containment sphere 4, in which, among others, one behind the other, a washing container 14 and, further downstream, a sorbent filter 18, precisely an iodine sorbent filter, disposed in a filtration chamber 16. Further downstream, the filtered depressurization flow is blown into the atmosphere through a chimney 20, in general, a exhaust outlet. The flow direction of the depressurization flow is indicated by arrows respectively.
[0098] [00098] As is evident in FIG. 1, the depressurization line 12 can also comprise an internal line segment 22 which is within the containment sphere 4, where an optionally pre-filter 24, in particular a metal pre-filter, is connected for aerosol retention thick. To bypass the pre-filter 24 if necessary, a bypass line 26 is provided that runs parallel to it and, depending on the demand, can be opened or closed.
[0099] [00099] One or more sealing valves 30 connected to the depressurization line 12 and in the normal operation of nuclear power plant 2 closed, may be arranged outside the containment sphere 4, as shown in FIG. 1, as an alternative or additionally also within the containment sphere 4. In order to start the depressurization process in the event of a fault with pressure increase in the internal space 6, the respective sealing valve 30 is opened, a fact that preferably , occurs automatically and without the use of foreign energy, for example, by means of a pressure-dependent triggering device.
[0100] [000100] For the adjustment of the best possible operating conditions aiming at the filtration objective in the sorbent filter 18, a series of technical measures is provided:
[0101] [000101] On the one hand, the flow of depressurization under relatively high pressure, coming from the internal space 6 of the containment sphere 4 (ventilation gas flow) is conducted through a washing liquid 32 in the washing container 14 and is thus purified , especially of thick aerosols.
[0102] [000102] For this purpose, the washing liquid 32 is maintained in a state of readiness of the depressurization system 8 in the washing container 14 with a minimum filling level 34. For the chemical conditioning of the washing liquid 32, especially to improve the filtration and retention properties can be added to the washing liquid 32 suitable agents, for example, sodium thiosulfate solution via a dosing device 36, in the present case only shown schematically.
[0103] [000103] In the ventilation operation, that is, in the case of depressurization, the flow of depressurization is directed into the washing container 14 through the line segment 38 of the depressurization line 12, and out there through a distributor 40 and then, a large number of parallel flow inlet nozzles 42. The inlet nozzles 42 are below the minimum filling level 34 in the so-called washing liquid pool 44, abbreviated pool, of the washing container 14, and are executed as Venturi nozzles. For this purpose, the respective inlet nozzle 42 has a Venturi tube 46 that contracts in certain areas, and at the narrowing point, also called the throat, an annular slit feed (not shown) is provided for the washing liquid 32 surrounding. The depressurization flow that in the ventilation operation flows through the Venturi tube 46 thus entrains the washing liquid 32 that enters the throat. The outlet openings facing the inlet nozzles 42 therefore eject a mixture of washing liquid and ventilation gas intimately mixed, and the impurities and aerosols contained in the flow of ventilation gas are deposited in the cleaning liquid. wash 32.
[0104] [000104] In the discharge zone 50 above the pool of washing liquid 44 the liquid and gaseous parts of the mixture of washing liquid and ventilation gas separate again due to the force of gravity. The washing liquid 32 eventually increased with condensate from the ventilation gas flow and enriched with aerosols and impurities (particles, soluble gases), goes back down into the washing liquid pool 44. The excess or condensed washing liquid 32 is withdrawn, as required, through a liquid discharge 54 connected to the bottom of the washing container 14, which can be closed with a sealing valve 52, so that the liquid level in the washing container 14 does not exceed a level of maximum fill preset 56. The ventilation gas purified by the washing process and still under high pressure, flows upwards through the outlet opening 62 of the washing container 14 and enters the next line segment 64 of the depressurization line 12 - after it passes through pressure separators. humidity 58 and possibly other filtration elements 60 arranged above the discharge zone 50 and above the maximum filling level 56.
[0105] [000105] On the other hand, the filtration chamber 16 itself with the sorbent filter 18 is preheated in the depressurization operation by means of heat transfer surfaces 66, 68 belonging to the depressurization flow coming from the line segment 64 , previously purified in the washing container 14 which is still more or less (at least with respect to the order of magnitude) at the pressure level in the internal space 6 of the containment sphere 4 and is relatively hot. Only after this release and heat transfer in the high pressure section 70 of the depressurization line 12 is the depressurization flow depressurized in a choke device 72 further downstream to approximately (at least with respect to the order of magnitude) environmental pressure and dried. The depressurizing line part 12 upstream of the choke device 72 is the high pressure section 70, the downstream part, and the low pressure section 74.
[0106] [000106] Following drying by expansion through the throttling device 72, the depressurization flow is conducted through an additional gas dryer 76 (optional) with a separate condensate separator and condensate collection vessel 78. Further downstream, the The depressurization flow in the low pressure section 74 of the depressurization line 12 is so conducted off the high pressure section 70 that on the respective heat transfer surfaces 68 of a superheat segment 80, a heat transfer from the gas in the high pressure section 70 for the gas flow in the low pressure section 74. Only after overheating has occurred, the depressurized depressurization flow is conducted through the filtration chamber 16 with the sorbent filter 18.
[0107] [000107] The thermal energy contained in the depressurization flow not yet relaxed in the high pressure section 70 is therefore used twice. On the one hand, heating of the filtration chamber 16 with the sorbent filter 18 disposed therein through the heat transfer surfaces 66, 68. On the other hand, through the heat transfer surfaces 68 there is an overheating of the relaxed depressurization flow immediately before entering the filtration chamber 16. In this way, due to the dimensioning and appropriate design of the components conducting the flow and the heat and possibly due to the proper adjustment of the cross section of the throttling device 72 and the other operating parameters, it is ensured that the depressurization flow in the superheat segment 80, that is, immediately before entering the filtration chamber 16 is heated up to a temperature that is at least 10 ° C above the prevailing dew point temperature, at full load operation of the depressurization system 8, at least 20 ° C. By combining these two measures, condensation of the flow of water is safely avoided depressurization in the filtration chamber 16 which could impair efficiency or even cause the permanent destruction of the filter d and sorbent 18.
[0108] [000108] FIG. 2 shows a little more detailed a concrete embodiment of the heat exchanger and absorbent filter unit 82 containing the heat transfer surfaces 66 and 68. The filtration chamber 16 is made as an annular chamber that surrounds in the form of a ring and especially coaxially a central chamber 84 having, for example, cylindrical or square shape. The longitudinal axis of the heat exchanger and absorbent filter unit 82 is oriented vertically. The filtration chamber 16 and the central chamber 84 are separated from each other in a gas impermeable manner through a separation wall 86 which conducts heat well - at least in a lower part. The filtration chamber 16, in turn, is divided by filtration elements 88 arranged annularly therein, in an internal inlet compartment 90, inwardly bounded by the separation wall 86, and an external outlet compartment 92. As an alternative for the type of annular chamber construction, a simple box construction method can also be envisaged, for example, a central chamber 84 in the shape of a cobblestone is followed by a filtration chamber 16 in the shape of a cobblestone in a side separated by a straight separation wall 86. Naturally, several filter chambers 16 separated from one another can also be connected to a central chamber 84 which, in connection with the relaxed pressure flow in the low pressure section 74, are connected in parallel.
[0109] [000109] The line segment 64 of the depressurization line 12 which in the direction of flow of the depressurization flow is moving away from the washing container 14 is connected to a system of heat transfer tubes 98 disposed in the internal space 94 of the chamber central 84 that in the direction of flow are connected in parallel, on its external side and eventually also on its internal side equipped with fins 98 (in the final areas the heat transfer tubes 98 are drawn in perspective, in the middle, only with simple lines ). For this purpose, the depressurization line 12 is conducted into the central chamber 84, at the end of the line segment 64 through a passage in the box 102 which on its external side is gas-tight, made in the ceiling 100 of the central chamber 84 and optionally, via a branch 104, connected to the heat transfer tubes 98. As an alternative, plate heat exchangers or other heat transfer elements can also be provided. The heat transfer tubes 98 are arranged in internal space 94 of the central chamber 84 in the form of meanders from top to bottom until the bottom area 106 where they rejoin in a collector 108. The collector 108 is connected on the outlet side a pipe 114 that passes through another passage of the box 110 of the box of the central chamber 112 that ends in the line segment 116 of the depressurization line 12 leading to the choke device 72.
[0110] [000110] The line segment 118 of the depressurization line 12 moving away from the choke device 72, after the gas dryer 76 optionally provided, goes back to the central chamber 84. The central chamber 84 therefore presents in the area bottom 106 is an entrance to the central chamber 120 to which the line segment 118 from the choke device 72 or the gas dryer 76 is connected (see also FIG. 1). At the upper end of the central chamber 84, in the vicinity of the ceiling box 100, a plurality of passage openings 122 are provided through the separation wall 86, which go from the internal space 94 of the central chamber 84 to the entrance compartment 90 of the chamber filter 16 and thus together constitute the entrance to the filtration chamber 124. Through the outlet of the filtration chamber 128 disposed downstream of the filtration elements 88 on the outside of the housing of the filtration chamber 126, for example, in its area bottom or also elsewhere, the outlet compartment 92 of the filtration chamber 16 is connected with the line segment 130 of the depressurization line 12 that goes to the chimney 20 (in FIG. 2 two flow outlets are provided parallel with the respective connections to the line that further downstream join again, which is not shown).
[0111] [000111] In this way, the depressurization flow coming in the line segment 64 of the washing container 14 that is under high pressure and relatively hot is conducted through the passage in the box 102 in the box to the central chamber 84 and through the transfer tubes of heat 98 arranged in it with direction of main flow that in essence points vertically from top to bottom. Then, the vent gas is conducted through line segment 116 to the choke device 72, dried by expansion and then conducted through gas dryer 76. Through line segment 118, the relaxed gas flow enters again in the central chamber 84. In the countercurrent or countercurrent crossed to the high pressure depressurization flow, it is conducted in the heat transfer tubes 98 essentially from the bottom upwards, passing through the heat transfer tubes 98, in order to, finally, through the passage openings 122 at the entrance of the filtration chamber 124 enter the filtration chamber 16, where the desired organoiodine filtration and retention takes place.
[0112] [000112] When passing through the heat transfer tubes 98 there is a heat transfer from the hot high pressure depressurization flow in the heat transfer tubes 98 to the low pressure depressurization flow conducted off the heat transfer tubes. 98 relaxed by the choke device 72 and dried. The tube walls of the heat transfer tubes 98 therefore constitute the heat transfer surfaces 68 of the superheat segment 80 formed by the internal space 94 of the central chamber 84, where the superheat already described above the relaxed depressurization flow occurs, before that the latter, in an overheated state, enters the inlet compartment 90 of the filtration chamber 16 through the inlet of the filtration chamber 124 formed by the passage openings 122, after which it passes through the filter elements 88 and finally, arriving through the outlet compartment 92, from the outlet of the filtration chamber 128 and the line segment 130 to the chimney 20 in a filtered state. At the same time - usually on a small scale - a heat transfer takes place through the separation walls 86 which conduct heat well and act as heat transfer surfaces 66, from the low pressure depressurization flow thus heated to the filtration chamber 16 which in this way is also respectively heated.
[0113] [000113] For an improvement of the heat transfer, the heat transfer tubes 98 can also have an appropriate structure inside, for example, have fins or have other inserts that generate turbulence or a twisted flow.
[0114] [000114] The depressurization system 8 according to FIG. 1 is also designed so that a partial flow of the depressurization flow in the high pressure section 70, as required, is conducted off the heat exchanger and absorbent filter unit 82, that is, it does not pass through the heat transfer tubes 98, the throttling device 72, the central chamber 84 and the filtration chamber 16. Therefore, this partial bypass flow does not contribute to the overheating of the low pressure depressurization flow in the superheat segment 80 nor to the heating of the heating chamber. filtration 16. For this purpose, at branch 142, downstream of the washing container 14 and upstream of the heat transfer tubes 98, a bypass line 144 is connected to the line segment 64 of the depressurization line 12, which in the entry point 148 downstream of the filter chamber outlet 128 again flows into the depressurization line 12, precisely in the line segment 130. To adjust the partial flow ratio, appropriate adjustment and adjustment devices must be provided (not shown). In addition, for adjusting the pressure level, a pressure reducing valve 150 is connected to the bypass line 144.
[0115] [000115] Condensate 132 formed on passing through heat transfer tubes 98 can be removed, as required, by a condensate discharge line 134 which derives from line 114 of line segment 116 and conducted , for example, even a container of condensate. The condensate discharge line 134, as shown in FIG. 1, can be joined to the liquid discharge line 54 of the washing container 14.
[0116] [000116] The filtration elements 88 of the sorbent filter 18 are preferably made of materials that absorb iodine and organoiodine, for example, solvent-free zeolites with open structure, that is, with an open pore system, and with doping of silver that in wet operation does not dissolve. If the occurrence of moisture in the sorbent filter 18 can certainly not be remedied in all operational states of the depressurization system 8, for example, through a corresponding design of the superheat efficiency in the superheat segment 80, they can be predicted or in all alternatively, zeolites with a doping or silver nitrate coating as filtration materials, whose retention effect for organoiodine surprisingly proved to be especially high with a sufficiently high dew point distance from the depressurization flow, should be mixed as an alternative.
[0117] [000117] In order to safely master special operating conditions, for example, when starting the operation, an additional heating device 136 operated with an external power source (for example, electrical) is optionally thermally coupled to the depressurization line 12 ). In FIG. 2, it is arranged, for example, inside or in the central chamber 84 of the heat exchanger and absorbent filter unit 82, as an alternative or additionally in the filtration chamber 16, especially in its inlet compartment 90. Of course, they are also other placement points imaginable.
[0118] [000118] In addition, devices for limiting the vacuum 138 can be provided, for example, in the line segment 38 between the outlet 10 of the containment sphere 4 and the washing container 14. In this way, it is prevented or quantitatively limited to formation of a vacuum in the containment sphere 4, for example, after ventilation and following partial condensation of the vapor present (for example, by connecting a spraying or cooling system) by aspirating air according to the need inside of the containment sphere 4.
[0119] [000119] For an active exhaustion of the mixture of gas and steam found in the containment sphere 4, a vacuum fan 140 can optionally be connected to the depressurization line 12, for example, upstream of the washing container 14, however, preferably, downstream of the sorbent filter 18 which is supplied with drive energy by an external energy source. The suction fan 140 is advantageously designed in such a way that in combination with a small water cover of the inlet nozzles 42 and relatively low nozzle speeds (<50 m / s) only thick aerosol pre-purification takes place here , but then optimized speeds can be regulated in the following filtration devices. In this way, it is possible to place and maintain the internal space 6 of the containment sphere at a low pressure (small) in relation to the ambient atmosphere, thus avoiding outward leaks completely.
[0120] [000120] In an alternative embodiment also shown in FIG. 1, in the case of a boiling water reactor, the washing container 14 (disposed outside the containment sphere 4) is dispensed. Instead, a wet filtration of the depressurization flow from the containment sphere 4 takes place still inside the containment sphere 4 in a condensing chamber 152 that exists there. The condensing chamber 152 is separated from the remaining internal space 6 in the containment sphere 4 by a gas-impermeable and pressure-resistant separation wall 154. A flow connection between the two parts of the space is only implemented through one or more overflow tubes 156 that immerse in the condensate liquid 158 in the condensing chamber 152. This means that the outlet opening 160 of the respective overflow tube 156 is below the minimum filling level 162 of condensate liquid 158. In this case, the depressurization line 12 (here drawn in dotted line) is connected to an outlet of the condensing chamber 164 which is arranged above the maximum filling level. in the gas collector space 170 above condensate liquid 158. In the example shown here, the outlet of the condensing chamber 164 coincides with the outlet 10 'of the containment sphere 4. Depressurization line 12' runs from outlet 10 ', without inserting a washer, directly to the heat exchanger and absorbent filter unit 82.
[0121] [000121] Finally, it is worth mentioning that the depressurization system 8 can have several parallel flow lines with the same or similar construction type. It is also possible that only some segments of the depressurization line 12 are duplicated by the parallel connection of similar components. In this, it may be appropriate to position several of the heat exchanger and absorbent filter units 82 shown in FIG. 2 towards a modular system directly adjacent and thermally coupled to each other, and precisely, preferably, with alternating arrangement of, for example, box-shaped central chambers 84 and respective filtration chambers 16. This is illustrated in FIG. 3.
[0122] [000122] Also in the variation shown in FIG. 4 of the depressurization system 8, the depressurization flow leaving the containment sphere 4, first, is purified in a washing container 14, further downstream, is relaxed by the choke device 72, eventually dried in a gas dryer 76, then it is conducted through a superheat segment 80 where regenerative heating takes place, and finally it is conducted through a filtration chamber 16 with a sorbent filter 18, before being released into the environment via chimney 20. As in the variations described above, a relatively large dew point distance of at least 10 ° C in full load operation is guaranteed by superheating the depressurization flow immediately before entering the filtration chamber, in order to prevent condensation separation in the area of the sorbent filter 18 and to achieve an especially effective retention of people with activities containing iodine.
[0123] [000123] Unlike the variations described above, in the system according to FIG. 4, the thermal energy required to overheat the low voltage depressurization flow and to heat the filtration chamber 16 is not transmitted directly from the high pressure depressurization flow. On the contrary, in this case, the washing liquid 32 held in the washing container 14, which in turn is heated by the incoming high-pressure flow, is used as the heat transfer and heating medium.
[0124] [000124] For this purpose, in the lower area of the washing liquid pool 44, that is, for example, clearly below the minimum fill level 34, the inlet end 180 of a circulation line 182 is connected to the washing container 14. The outlet end 184 of the circulation line 182 is connected to the washing container 14 geodesically higher than the inlet end 180, as shown here, for example, just below the minimum fill level 34 or slightly highest in the discharge zone 50. Circulation line 182 - activated in the ventilation operation by the flow impulse of the ventilation gas flow that enters the washing container 14 through the inlet nozzles 42 - is crossed in the direction of flow 186 by a mixture of washing liquid and ventilation gas (containing bubbles). The washing liquid 32 mixed with the ventilation gas is then removed from the washing container 14 at a relatively low point and - after an intersecting rising segment 188 - at a higher point, it is again circulated back into it like a washing liquid circuit. For an especially good use of the drive impulse, at least one of the inlet nozzles 42 is oriented towards the inlet end 180 of the circulation line 182, in this case, therefore, downwards (diagonally). In this, the circulation is supported according to the principle of natural circulation due to differences in density between the washing liquid 32 (pure) and the mixture of washing liquid and ventilation gas (containing bubbles).
[0125] [000125] In the ascending segment 188 of circulation line 182, the circulating washing liquid 32, mixed with ventilation gas, is conducted from the bottom upwards through a number of heat transfer tubes 98 of parallel flow (or also other heat transfer elements) which are arranged within the central chamber 84 of the heat exchanger and absorbent filter unit 82 in approximately vertical alignment. The depressurization flow coming from the washing vessel 14 in the line segment 192 of the depressurizing line 12 through the choke device 72 and the gas dryer 76, filtered in the wet filtration, is in turn conducted in countercurrent to the washing liquid 32 which circulates through heat transfer tubes 98, that is, from top to bottom, on the outside, along heat transfer tubes 98, through central chamber 84. Depressurization flow passes through central chamber 84 before , through passage openings 122 arranged in a lower area in the separation wall 86 between the central chamber 84 and the filtration chamber 16 that constitute the entrance of the filtration chamber 124, enter the filtration chamber 16 with the sorbent filter 18 (The inlet of the filtration chamber 124, as a rule, is further down in the vicinity of the bottom of the separation wall 86 than is shown here in FIG. 4 purely schematically).
[0126] [000126] Similarly to the variation described in the context of FIG. 1 and FIG. 2, the tube walls of the heat transfer tubes 98 and the separation wall 86 constitute the heat transfer surfaces 66 and 68 for a heat transfer from the circulating washing liquid 32 to the low pressure depressurization flow, for example. on the one hand, and the filtration chamber 16 on the other. In this, the part of the central chamber 84 traversed by the low pressure depressurization flow constitutes the superheat segment 80 which in the flow direction is connected in series immediately before the filtration chamber 16.
[0127] [000127] Finally, FIG. 5 shows details of another variation of the depressurization system 8. It comprises a combined washer and heat exchanger and sorbent filter 200 unit. By the concept it can be imagined that for this purpose the washing container 14 and the heat exchanger and absorbent filter unit 82 of the depressurization system 8 according to FIG. 1 are arranged and integrated in a common box 202.
[0128] [000128] Concretely the washer and heat exchanger unit and sorbent filter 200 shown in FIG. 5 in a longitudinal section comprises a washing area 206 filled with washing liquid 32 up to at least a minimum filling level 204, arranged at the bottom of the housing 202. Through a pipe 208 that passes through a passage in the housing and a distributor 40 going in the direction of flow, a depressurization flow taken from the containment sphere of a nuclear power plant is conducted to a number of inlet nozzles 42 of parallel flow. At the outlet of the wash liquid pool 44 the flow of ventilation gas is subjected to wet filtration, similarly to the wash container 14 known from FIG. 1.
[0129] [000129] After separating the mixture of washing liquid and ventilation gas, the flow of ventilation gas under high pressure, purified and free of thick aerosols, passes through the central space 210 and flow channels 212 and 214 or corridors that in part pass by the external filtration chamber 16 and are in thermal contact with it, for the ceiling area 216 of the box 202 upwards, it is deflected and through flow channels 218 it enters in humidity separators 58 and filtration elements 60 For the most intense preheating, a partial flow of the high pressure depressurization flow can be removed via a heating device 228 and bypassing the heat transfer tubes 98 connected in series in the flow (see below), be conducted directly through the sorbent filter 18 or the area connected in series upstream. On the outlet side the respective filter element 60, the depressurization flow is carried through a flow channel 220 to a choke device 72 and depressurized there. In the next low-pressure segment, the depressurized ventilation gas first passes through a plurality of heat transfer tubes 98 of parallel flow further down, in return segment 222 with suitable contours of the elements leading the flow is forced to invert the direction and flows back upwards through the following heat transfer tubes 98 which in the flow direction are parallel in series and geometrically with the heat transfer tubes 98 leading downwards, to the passage openings 128 that make up the inlet of the filtration chamber 124 into the filtration chamber 16. The filtration chamber of the device, analogously to the filtration chamber 16, is constructed according to FIG. 1 or FIG. 2. Through the outlet of the filtration chamber 128 the depressurization flow filtered in the sorbent filter 18 enters a pipe that goes up to the chimney (not shown here).
[0130] [000130] Through the flow channels 214 conducted off the filtration chamber 16 for the high pressure depressurization flow, heating of the filtration chamber 16 occurs. The separation walls 86 that conduct heat between the flow channels 214 and the in this, the filtration chamber 16 constitutes the heat transfer surfaces 66. In addition, the tube walls of the heat transfer tubes 98 constitute heat transfer surfaces 68 between the relatively hot high-pressure depressurization flow that passes through the central space 210 and the low pressure depressurization flow in the heat transfer tubes 98 which, before entering the filtration chamber 16, need to be overheated for a dew point distance of at least 10 ° C, preferably above 20 ° C. Therefore , the heat transfer tubes 98 constitute the superheat segment 80 for the depressurization flow that was previously depressurized in the device of strangulation 72.
[0131] [000131] In the operating state shown in FIG. 5, the liquid level 224 of the washing liquid 32 is more or less in the range of the minimum fill level 204 and therefore below the inversion segments 222 and the heat transfer tubes 98 above them. The heat transfer tubes 98 are heated exclusively or in any case predominantly in a "dry" manner by the high pressure depressurization flow carried out outside them, previously purified in the washing liquid pool 44. With a more filling level high and therefore with a liquid level 224 which is located higher up in the area of the heat transfer tubes 98, on the other hand, it is also possible to heat partly or even completely "wet" the heat transfer tubes 98 through the washing liquid 32 which in turn is heated by the ventilation gas entering through the inlet nozzles 42. The maximum permissible filling level 226 is just below the moisture separators 58 or filter elements 60. REFERENCE LISTING 2 Nuclear plant 4 Containment sphere 6 Indoor space 8 Depressurization system 10, 10 'Output 12, 12 'Depressurization line 14 Wash container 16 Filtration chamber 18 Sorbent filter 20 Chimney 22 Line segment 24 Pre-filter 26 Bypass line 28 Regulating valve 30 Sealing valves 32 Washing liquid 34 Minimum filling level 36 Dosing device 38 Line segment 40 Distributor 42 Inlet nozzle 44 Washing liquid pool 46 Venturi Tube 48 Exit opening 50 Discharge zone 52 Sealing valve 54 Liquid discharge line 56 Maximum filling level 58 Moisture separator 60 Filter element 62 Exit opening 64 Line segment 66 Heat transfer surface 68 Heat transfer surface 70 High pressure section 72 Choke device 74 Low pressure section 76 Gas dryer 78 Condensate collector container 80 Overheat segment 82 Heat exchanger and sorbent filter unit 84 Central Chamber 86 Partition wall 88 Filter element 90 Inlet compartment 92 Output compartment 94 Indoor space 96 Fins 98 Heat transfer tube 100 Ceiling box 102 Passing through the box 104 Branching 106 Bottom area 108 Collector 110 Pass through the box 112 Central chamber box 114 Piping 116 Line segment 118 Line segment 120 Central chamber entrance 122 Through opening 124 Filtration chamber inlet 126 Filter chamber 128 Filter chamber outlet 130 Line segment 132 Condensate 134 Condensate discharge line 136 Additional heating device 138 Vacuum limitation 140 Vacuum fan 142 Branching 144 Bypass line 148 Point of entry 150 Pressure reduction valve 152 Condensing chamber 154 Partition wall 156 Thief tube 158 Condensate liquid 160 Exit opening 162 Minimum fill level 164 Condensation chamber outlet 170 Gas collector space 180 Input end 182 Circulation line 184 Output end 186 Flow direction 188 Climb segment 192 Line segment 200 Washer and heat exchanger unit and sorbent filter 202 Box 204 Minimum fill level 206 Washing area 208 Piping 210 Central space 212 Flow channel 214 Flow channel 216 Ceiling area 218 Flow channel 220 Flow channel 222 Inversion segments 224 Liquid level 226 Maximum fill level 228 Heating device

权利要求:
Claims (21)
[0001]
Process for depressurizing a nuclear power plant (2) with a containment sphere (4) to contain activity carriers and with an outlet (10, 10 ') for a depressurization flow, with the depressurization flow being conducted through a depressurization line (12, 12 ') equipped with a filtration system out of the containment sphere (4) into the atmosphere, the filtration system comprising a filtration chamber (16) with a chamber inlet filter (124), a filter chamber outlet (128) and a sorbent filter (18) disposed between the two, and the flow of depressurization - first it is conducted in a high pressure section (70), - then it is relaxed by means of expansion in a choke device (72), - then, at least partially, it passes through the filtration chamber (16) with the sorbent filter (18), and, - it is finally blown into the atmosphere, characterized by the fact that the flow of depressurization relaxed by the choke device (72), immediately before entering the filtration chamber (16), is conducted through a superheat segment (80) where it, through direct or indirect heat transfer of the flow of depressurization not yet relaxed in the high pressure section (70), it is heated to a temperature that is above the prevailing dew point temperature at least 10 ° C, preferably 20 ° C to 50 ° C.
[0002]
Process according to claim 1, characterized in that the flow of depressurization in the high pressure section (70), at least partially, is conducted off the filtration chamber (16), which is heated by means of heat transfer .
[0003]
Process according to claim 1 or 2, characterized by the fact that a central chamber (84) is provided that surrounds the filtration chamber (16) or is adjacent to it, with the depressurization flow in the high pressure section ( 70) is conducted through heat transfer elements (98) arranged in it or projecting into it, and the flow of depressurization in the superheat segment (80) is conducted externally off the heat transfer elements ( 98) through the central chamber (84).
[0004]
Process according to any one of claims 1 to 3, characterized in that the flow of depressurization in the superheat segment (80) is conducted through a washing container (14) containing washing liquid (32), with a number of inlet nozzles (42), preferably of the Venturi washer type.
[0005]
Process according to any one of claims 1 to 3, characterized in that the flow of depressurization is removed from a condensation chamber (152) of a nuclear reactor, especially from a boiling water reactor, and from there, without interleaving a washing vessel is conducted off the filter chamber (16) for heating it.
[0006]
Process according to claim 4, characterized in that the washing liquid (32) of the washing container (14) is conducted through a circulation line (182) which, at least with part, is in thermal contact with the filtration chamber (16), heating it by means of heat transfer from the circulating washing liquid (32).
[0007]
Process according to claim 6, characterized by the fact that the flow of depressurization relaxed by the choke device (72) in the superheat segment (80) is in thermal contact with the circulation line (182) and is heated by means of heat transfer from the circulating washing liquid (32).
[0008]
Process according to claim 6 or 7, characterized in that the flow of the washing liquid (32) through the circulation line (182) is triggered by the impulse transmitted by the depressurization flow to the washing liquid (32).
[0009]
Process according to any one of claims 6 to 8, characterized in that the washing liquid (32) removed from the washing container (14), after passing through the circulation line (182), is taken back to the washing container (14) at a geodesically higher point.
[0010]
Process according to any one of claims 6 to 9, characterized in that the filtration chamber (16) surrounds or is adjacent to a central chamber (16), the circulating washing liquid (32) being conducted through of heat transfer elements (98), especially heat transfer tubes, arranged in the central chamber (84) or projecting into it, and the flow of depressurization in the superheat segment (80) is externally conducted to the width of the heat transfer elements (98) through the central chamber (84).
[0011]
Depressurization system (8) for a nuclear power plant (2) with a containment sphere (4) for the retention of activity carriers and with an outlet (10, 10 ') for a depressurization flow, with a depressurization line (12, 12 ') provided with a filtration system is connected to the outlet (10, 10'), the filtration system comprising a filtration chamber (16) with an inlet of the filtration chamber (124), an outlet filtration chamber (128) and a sorbent filter (18) between the two, and - the depressurization line (12, 12 ') comprises a high pressure section (70), - at the end of the high pressure section (70), a choke device (72) is connected to the depressurization line (12), - the depressurization line (12, 12 ') downstream of the throttling device (72) ends at the entrance of the filtration chamber (124), and - the outlet of the filtration chamber (128) is connected to a chimney (20) which leads to the atmosphere, characterized by the fact that the depressurization line (12, 12 ') has between the choke device (72) and the inlet of the filtration chamber (124) a superheat segment (80) which is thermally coupled through heat transfer surfaces (68) to the high pressure section (70), where these heat transfer surfaces (68) are dimensioned in such a way that the depressurization flow that occurs under design failure conditions in the superheat segment (80) is heated to a temperature which is higher than the dew point temperature prevailing at least 10 ° C, preferably 20 ° C to 50 ° C.
[0012]
Depressurization system (8) according to claim 11, characterized in that the high pressure section (70), at least in a partial section, passes through the filtration chamber (16) and is thermally coupled to the chamber filtration (16) through heat transfer surfaces (66, 68), so that the filtration chamber (16) is heated by the depressurization flow.
[0013]
Depressurization system (8) according to claim 11 or 12, characterized in that the filtration chamber (16) surrounds or is adjacent to a central chamber (84), one or more elements of heat transfer (98) that can be traversed are arranged in the central chamber (84) or protrude into it, and the flow conduction in the depressurization line (12) is carried out in such a way that the depressurization flow in the high section pressure (70) passes through the heat transfer elements (98) and in the superheat segment (80), it is conducted externally off the heat transfer elements (98) through the central chamber (84).
[0014]
Depressurization system (8) according to any of claims 11 to 13, characterized in that in the high pressure section (70), a washing container (14) containing washing liquid (32) with at least one nozzle inlet (42), preferably of the Venturi washer type, is connected to the depressurization line (12).
[0015]
Depressurization system (8) according to any of claims 11 to 13 for a nuclear power plant (2) with a boiling water reactor featuring a condensing chamber (152), characterized by the fact that the depressurization line (12 ' ) is connected to the condensation chamber (152) on the side of the flow inlet, and from there, without an interposed washing container, it is conducted off the filter chamber (16) for heating it.
[0016]
Depressurization system (8) according to claim 14, characterized by the fact that a circulation line (182) for the circulation of washing liquid (32) is connected to the washing container (14), the line of which is circulation (182) passes along the filtration chamber (16), being in thermal contact with it, so that a transfer of heat from the washing liquid (32) to the filtration chamber (16) occurs.
[0017]
Depressurization system (8) according to claim 16, characterized by the fact that the superheat segment (80) of the depressurization line (12) is thermally coupled to the circulation line (182) through heat transfer surfaces ( 68), so that there is a heat transfer from the circulating washing liquid (32) to the depressurization flow.
[0018]
Depressurization system (8) according to claim 16 or 17, characterized by the fact that the filtration chamber (16) surrounds a central chamber (84) or is adjacent to it, the circulation line (182) having one or more heat transfer elements (98), which in the depressurization operation passes the washing liquid (32), which are arranged in the central chamber (84) or protrude into it, and the conduction of the flow in the depressurization line (12) it is carried out in such a way that the flow of depressurization in the superheat segment (80) is conducted externally along the heat transfer elements (98) through the central chamber (84).
[0019]
Depressurization system (8) according to any one of claims 16 to 18, characterized in that the circulation line (182) has a washing liquid inlet (180) that flows into the washing container (14), and a washing liquid outlet (184) which also flows into the washing container (14) at a higher point in relation to the washing liquid inlet (180).
[0020]
Depressurization system (8) according to any one of claims 16 to 19, characterized in that at least one of the inlet nozzles (42) is aligned in such a way that the impulse transmitted to the washing liquid (32) of the depressurization flow through it triggers the circulation of the washing liquid (32) through the circulation line (182).
[0021]
Nuclear plant (2), characterized by the fact that it comprises a containment sphere (4) for the containment of activity carriers and with a depressurization system (8), as defined in any of claims 11 to 20.

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BR112013004332A2|2016-05-31|

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JP2013540989A|2013-11-07|

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UA107392C2|2014-12-25|

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CA2806390C|2017-03-07|

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引用文献:

---

公开号 | 申请日 | 公开日 | 申请人 | 专利标题

---

---

US3930937A|1973-04-02|1976-01-06|Combustion Engineering, Inc.|Steam relief valve control system for a nuclear reactor|

---

DE3729501A1|1987-03-23|1988-10-06|Siemens Ag|METHOD AND DEVICE FOR RELEASING PRESSURE FROM A NUCLEAR POWER PLANT|

---

DE3815850C2|1988-05-09|1993-05-06|Siemens Ag, 1000 Berlin Und 8000 Muenchen, De|

---

DE3824606C2|1988-07-20|1992-01-09|H. Krantz Gmbh & Co, 5100 Aachen, De|

---

DE3825606C2|1988-07-28|1993-12-23|Heidenhain Gmbh Dr Johannes|Interferometer|

---

DE3901784A1|1989-01-21|1990-07-26|Kernforschungsz Karlsruhe|Process and adsorbent for removing iodine and/or organic iodine compounds from gases and/or vapours|

---

DE4126894A1|1991-08-14|1993-02-18|Siemens Ag|METHOD AND DEVICE FOR OBTAINING SAMPLES FROM THE ATMOSPHERIC CONTAINER CONTAINED IN A GAS-TIGHT, IN PARTICULAR FROM THE REACTOR SAFETY CONTAINER OF A NUCLEAR POWER PLANT|

---

CH682524A5|1991-09-30|1993-09-30|Asea Brown Boveri|Device for monitoring the atmosphere inside the containment vessel of a reactor plant.|

---

CA2106841C|1992-09-24|1999-08-31|Nobuyuki Manabe|System for washing a tank and recovering and treating residual tank liquid and method of operating the system|

---

US5268939A|1992-10-19|1993-12-07|General Electric Company|Control system and method for a nuclear reactor|

---

JP3148046B2|1993-06-01|2001-03-19|株式会社日立製作所|Suppression pool in reactor containment vessel|

---

JPH07104087A|1993-10-07|1995-04-21|Toshiba Corp|Vent device for reactor container|

---

JP2000002782A|1998-06-16|2000-01-07|Toshiba Eng Co Ltd|Control unit for atmosphere inside reactor container|

---

JP3721269B2|1998-09-10|2005-11-30|株式会社日立製作所|Reactor containment vessel equipped with flammable gas treatment equipment|

---

DE10328773B3|2003-06-25|2005-02-17|Framatome Anp Gmbh|Nuclear facility|

---

DE10328774B3|2003-06-25|2005-01-13|Framatome Anp Gmbh|Nuclear plant with pressure relief|

---

DE102004050308A1|2004-10-14|2006-06-14|Framatome Anp Gmbh|Method and sampling system for recovering a sample from the atmosphere in a reactor containment of a nuclear facility|

---

RU2302674C1|2005-12-20|2007-07-10|Федеральное государственное унитарное предприятие "Научно-исследовательский, проектно-конструкторский и изыскательский институт "Атомэнергопроект", ФГУП "Атомэнергопроект"|Containment heat transfer system|JP2013185827A|2012-03-05|2013-09-19|Mitsubishi Heavy Ind Ltd|Shield structure and shield method|

---

DE102012005204B3|2012-03-16|2013-01-17|Westinghouse Electric Germany Gmbh|Method for dimensioning of diaphragm and drying filter for reactor pressure relief filter system, involves dimensioning of panel, such that desired gas mass flow is set at predetermined pressure in interior space|

---

CN103325427B|2012-03-19|2016-06-01|中科华核电技术研究院有限公司|A kind of Passive containment cooling system and method|

---

CN102723114A|2012-05-30|2012-10-10|中国核电工程有限公司|Containment filtering and discharging system|

---

US9502144B2|2012-07-06|2016-11-22|Westinghouse Electric Company Llc|Filter for a nuclear reactor containment ventilation system|

---

DE102012211897B3|2012-07-09|2013-06-06|Areva Np Gmbh|Nuclear plant e.g. boiling-water reactor type nuclear power plant, for producing current, has flow channel, where mixture flows into channel according to forced flow principle, and disperses above discharge line as pressure discharge flow|

---

DE102012213614B3|2012-08-01|2014-04-03|Areva Gmbh|Containment protection system for a nuclear installation and related operating procedure|

---

JP5898018B2|2012-08-27|2016-04-06|日立Ｇｅニュークリア・エナジー株式会社|Containment Vessel Filter Vent Device and Reactor Containment Vessel|

---

DE102013205525A1|2013-03-27|2014-10-02|Areva Gmbh|Venting system for the containment of a nuclear facility|

---

DE102013205524A1|2013-03-27|2014-10-02|Areva Gmbh|Venting system for the containment of a nuclear facility|

---

DE102013207595B3|2013-04-25|2014-09-25|Areva Gmbh|Emission monitoring system for a venting system of a nuclear power plant|

---

JP5853054B2|2013-06-19|2016-02-09|コリア アトミック エナジー リサーチ インスティチュート|Reactor containment cooling system|

---

US10176901B2|2013-08-14|2019-01-08|Ge-Hitachi Nuclear Energy Americas Llc|Systems, methods, and filters for radioactive material capture|

---

FR3009862B1|2013-08-26|2015-09-11|Commissariat Energie Atomique|HEAT EXCHANGER BETWEEN TWO FLUIDS, USE OF THE EXCHANGER WITH LIQUID METAL AND GAS, APPLICATION TO A QUICK-NEUTRON NUCLEAR REACTOR COOLED WITH LIQUID METAL|

---

DE102013222272A1|2013-11-01|2014-11-20|Areva Gmbh|Pressure relief system for a nuclear power plant and associated method|

---

US9805833B2|2014-01-06|2017-10-31|Bwxt Mpower, Inc.|Passively initiated depressurization valve for light water reactor|

---

EP2937867B1|2014-03-03|2018-11-14|Fnctech|Containment filtered venting system used for nuclear power plant|

---

KR101513725B1|2014-03-03|2015-04-22|주식회사 미래와도전|Cfvs for nuclear power plant|

---

CN103871495B|2014-03-07|2016-06-29|长江勘测规划设计研究有限责任公司|Containment pressure relief system under underground nuclear power station major accident|

---

CN103900842B|2014-03-22|2016-06-29|哈尔滨工程大学|A kind of self-priming venturi water scrubber performance test system|

---

CN104409112B|2014-12-03|2017-07-04|中国核动力研究设计院|Containment recirculating system|

---

US10937555B2|2014-12-19|2021-03-02|Caverion Deutschland GmbH|Nuclear power plant|

---

DE102015200679A1|2015-01-16|2016-07-21|Areva Gmbh|Ventilation system and associated operating method for use during a major accident in a nuclear facility|

---

RU2661906C1|2015-03-12|2018-07-23|Раса Индастриз, Лтд.|Filtering material for filtering ventilation and filtering ventilation device|

---

CN104979020B|2015-05-20|2017-05-03|中国核动力研究设计院|Hydrogen risk control system and control method for small-power nuclear reactor containment|

---

KR101656314B1|2015-08-11|2016-09-12|한국수력원자력 주식회사|Radioactive materials filtration system|

---

CN106504811B|2016-10-31|2017-12-19|哈尔滨工程大学|A kind of long-term release filtration system of containment|

---

JP6876447B2|2017-01-24|2021-05-26|日立Ｇｅニュークリア・エナジー株式会社|Nuclear power plant|

---

KR102020908B1|2017-12-19|2019-09-11|한국원자력연구원|Main steam system that reduces the release of radioactive material to the atmosphere under severe accident|

---

JP6927893B2|2018-01-18|2021-09-01|日立Ｇｅニュークリア・エナジー株式会社|Reactor containment vent system|

---

KR102153957B1|2018-11-08|2020-09-09|한국과학기술원|System and method for mitigating dispersion of radioactive substance in steam generator tube rupture accidents|

---

KR102113284B1|2019-01-22|2020-05-20|한국원자력연구원|system and a method for reducing the release of radioactive material to the atmosphere under severe accident|

---

CN110379533B|2019-06-26|2021-01-19|中广核工程有限公司|Chemical dosing and liquid supplementing device and method for containment filtering and discharging system of nuclear power plant|

法律状态:
2017-11-28| B25D| Requested change of name of applicant approved|Owner name: AREVA GMBH (DE) |

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2018-12-26| B06F| Objections, documents and/or translations needed after an examination request according [chapter 6.6 patent gazette]|

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2019-04-24| B25A| Requested transfer of rights approved|Owner name: FRAMATOME GMBH (DE) |

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2019-10-22| B06U| Preliminary requirement: requests with searches performed by other patent offices: procedure suspended [chapter 6.21 patent gazette]|

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2020-11-03| B09A| Decision: intention to grant [chapter 9.1 patent gazette]|

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2021-01-26| B16A| Patent or certificate of addition of invention granted [chapter 16.1 patent gazette]|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 18/07/2011, OBSERVADAS AS CONDICOES LEGAIS. |

优先权:

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申请号 | 申请日 | 专利标题

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DE102010035509.7|2010-08-25|

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DE102010035509A|DE102010035509A1|2010-08-25|2010-08-25|Process for pressure relief of a nuclear power plant, pressure relief system for a nuclear power plant and associated nuclear power plant|

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PCT/EP2011/003574|WO2012025174A1|2010-08-25|2011-07-18|Method for depressurizing a nuclear power plant, depressurization system for a nuclear power plant, and associated nuclear power plant|

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