• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    3It is an object of the invention to provide an improved method and system for monitoring the amount of fluid being dispensed which at least partially eliminates some of the problems described above.Summary of the inventionAccording to a first aspect, the object is achieved at least in part through a dosing system. The dosing system comprises a container with fluid which is intended to be dosed, a pump Pu which is arranged to pump fluid from the container via a first pipe, a dosing unit which is connected downstream of the pump.Pu via a second pipeline and which is arranged to dose the fluid, a control unitarranged to control the amount of fluid to be dosed in the Iran dosing unit, and a detector unit arranged to detect a fluid parameter 9 indicating a fluid flow in the first pipeline upstream of the pump Pu and generate a fluid signal indicating the fluid parameter 9.The control unit is further arranged to: determine a time period At during whichthe dosing unit is open; constituting a first fluid flow in the first pipeline upstream of the pump Pu; comparing the first fluid flow in the first pipeline upstream of the pump Pu with a second fluid flow Iran dosing unit during the time period ;t; determine an error parameter based onthe result of the comparison; and generate a signal indicating the error parameter.Through the dosing system one can monitor the dosing of fluid, and other amounts if the dosing is incorrectly active. By supplying the pressure upstream of the pump Pu, the flow of fluid to the dosing unit was not so great. The inventor hasrealized that the pressure on the suction side is linear with the dosed flow. Oneflow feeder on the pressure side, ie downstream of the pump Pn, partially restricts the flow and / or it can be practical problems to find a place with the river feeder. A throttling of the river must be compensated with a high pressure, which meant that the pump Pn had to work more, which is not unfortunate. By applying pressurethe suction side instead avoids the need to have a river feeder onprint side. The fluid can be a reducing agent such as AdBlue®.
    公开号:SE1450493A1
    申请号:SE1450493
    申请日:2014-04-25
    公开日:2015-10-26
    发明作者:Max Lindfors
    申请人:Scania Cv Ab；
    IPC主号:
    专利说明:

    Dosing system and method for monitoring the amount of fluid dosed by the dosing systemFIELD OF THE INVENTIONThe present invention relates to a technique for dosing a fluid, and inin particular to a method and system for monitoring the amount of fluid dosed by a dosing system. The invention also relates to an exhaust after-treatment system comprising the dosing system, a vehicle comprising the dosing system and a program and a computer program product.
    Background of the inventionAn internal combustion engine burns an air and fuel mixture and generates exhaust gases that include nitrogen oxides (NOx), carbon dioxide (CO2), carbon monoxide (CO) and particles. NO is a collective name used for the firsthand nitrogen oxide (NO) and nitrogen dioxide (NO2). To reduce emissionsharmful constituents, it is common to install an exhaust after-treatment system in the exhaust line Than engine. In order to reduce the NO content, it is common in diesel engines for the exhaust after-treatment system to include a SCR (Selectiv Catalytic Reduction) catalyst in combination with asystems for injecting a reduction needle into the SCR catalyst.
    The reducing agent reacts in the SCR catalyst with the nitrogen oxides and reduces the amounts of NOx released into the atmosphere. The reducing agent is broken down to form ammonia (NH3) which in turn reacts with NOx to form water and nitrogen gas (N2).
    The system for injecting the reducing agent needs to have high accuracy in its dosing, in order to achieve the intended exhaust gas purifying effect. There may be NON sensors both upstream and downstream of the SCR catalyst that feed the amount of NOx into the exhaust gases. The system can then adjust the amount of reducing agentdepending on the amount of NOx in the exhaust gases by regulating a metering valve. The system is usually calibrated by correlating the opening time of the metering valve2with nnangden injected reducing agent. This connection is then used in the regulation of the metering valve.
    However, a dosing valve may differ from the production from another apparentlysimilar dosing valve. A metering valve is also subject to wear and can change itsbehavior during its lifetime.
    To ensure that the correct amount is dosed, there are solutions where the flow of reducing agent is fed. One problem with these solutions, however, is thatthe river feeder itself causes a restriction of the flow of reducing agent which is not undesirable and which must be compensated for and which then places higher demands on the pump in the system. Another problem is that there can be practical problems with getting space with the river feeder.
    US20110239625A1 discloses a solution for adapting a urea injector tocompensate for manufacturing tolerances and wear of the dosing system. This problem is solved by performing a status check which includes feeding the pressure change in the system between pump and injector when the injector is opened and comparing it with a desired value. If the values are different, so can the valvethe opening period is varied so that the injected urea discharge becomes correct.
    DE102011078870A1 describes how to use pressure supply in onedosing system to monitor the function of the dosing valve and the feed pump and to monitor the amount of dosed AdBlue. To feed the amount dosedAd Blue is used that each valve opening causes a pressure change in the system.
    US8534049B2 describes a process for operating an electromagnetic valve which regulates how much reactant is to be injected into the exhaust gases. Based on pressure supply in the dosing system, you can regulate how long it laststhe solenoid valve must be open or closed.3It is an object of the invention to provide an improved method and system for monitoring the amount of fluid being dispensed which at least partially eliminates some of the problems described above.
    Summary of the inventionAccording to a first aspect, the object is achieved at least in part through a dosing system. The dosing system comprises a container with fluid which is intended to be dosed, a pump Pu which is arranged to pump fluid from the container via a first pipe, a dosing unit which is connected downstream of the pump.Pu via a second pipeline and which is arranged to dose the fluid, a control unitarranged to control the amount of fluid to be dosed in the Iran dosing unit, and a detector unit arranged to detect a fluid parameter 9 indicating a fluid flow in the first pipeline upstream of the pump Pu and generate a fluid signal indicating the fluid parameter 9.
    The control unit is further arranged to: determine a time period At during whichthe dosing unit is open; constituting a first fluid flow in the first pipeline upstream of the pump Pu; comparing the first fluid flow in the first pipeline upstream of the pump Pu with a second fluid flow Iran dosing unit during the time period ;t; determine an error parameter based onthe result of the comparison; and generate a signal indicating the error parameter.
    Through the dosing system one can monitor the dosing of fluid, and other amounts if the dosing is incorrectly active. By supplying the pressure upstream of the pump Pu, the flow of fluid to the dosing unit was not so great. The inventor hasrealized that the pressure on the suction side is linear with the dosed flow. Oneflow feeder on the pressure side, ie downstream of the pump Pn, partially restricts the flow and / or it can be practical problems to find a place with the river feeder. A throttling of the river must be compensated with a high pressure, which meant that the pump Pn had to work more, which is not unfortunate. By applying pressurethe suction side instead avoids the need to have a river feeder onprint side. The fluid can be a reducing agent such as AdBlue®.4According to one embodiment, the control unit is arranged to generate a control signal whichatnninstone indicates an opening time for the dosing unit which is adjusted according to the error parameter. In this way, the opening time of the dosing unit canregulated so that the required amount of fluid is dosed.
    According to one embodiment, the detector unit is arranged to detect oneflu id parameter cp which is a pressure parameter. The need for a river feeder on the suction side can then be avoided.
    According to one embodiment, the control unit is arranged to determine the time period .t. This can be done, for example, based on the measured value of NOx.
    According to one embodiment, the control unit is adapted to determine the otherthe fluid flow. The second fluid flow may be a predetermined value depending onpressure P2. For example, the second fluid flow may be calibrated varden and / or varden as phase from the manufacturer.
    According to one embodiment, the dosing system comprises an additional detector unitwhich is arranged to detect a pressure P2 in the fluid downstream of the pump Pu, the pump Pu being arranged to maintain a desired pressure in the fluid in the second pipeline downstream of the pump Pu. The desired pressure is thus an edge pressure for the control unit.
    According to one embodiment, the control unit is arranged to compare the first fluid flowwith the second fluid flow for a plurality of time periods At when the dosing unit is open, determine an average error parameter based on the comparisons, and generate a signal indicating the average error parameter. In this way you can get a more robust monitoring of the dosing unit.
    According to one embodiment, the control unit is arranged to adjust the opening time of the dosing unit in accordance with the error parameter. In this way you can get a robust control of the dosing unit.
    According to one embodiment, the control unit is arranged to generate another control signaldosing unit To periodically adjust the opening time of the dosing unit based on the error parameter. According to another embodiment, the control unit is arranged to generate a control signal to the dosing unit in order to continuously adjust the opening time of the dosing unit based on the error parameter.
    According to a second aspect, the object is achieved at least in part by a method for monitoring the amount of fluid dosed by a dosing system. The dosing system comprises a container with fluid which is intended to be dosed, a pump Pu which is arranged to pump fluid than the container via a first pipeline, adosing unit connected downstream of the pump Pu via a second pipeline and arranged to dose the fluid, a control unit arranged to control the amount of fluid to be dosed from the dosing unit and a detector unit arranged to detect a fluid parameter p indicating a fluid flow in the first pipeline upstream of the pump Pu. The method includesto:determine a time period At during which the dosing unit is open;detecting the fluid parameter on the upstream pump Pu during the time period ;t;determining a first fluid flow in the first pipeline upstream of the pump Pu;compare the first fluid flow in the first pipeline upstream of the pump Puwith a second fluid flow from the dosing unit during the time period Att; anddetermine an error parameter based on the result of the comparison.
    According to one embodiment, the method comprises adjusting the opening time of the dosing unit in accordance with the error parameter.
    According to one embodiment, the fluid parameter 9 is a pressure parameter.6According to another embodiment, At is a time period determined by the control unit.
    According to a further embodiment, the second fluid flow is determined by the control unit.
    According to one embodiment, the dosing system comprises an additional detector unit which is arranged to detect a pressure P2 in the fluid downstream of the pump Pu, the pump Pu being arranged to maintain a desired pressure in the fluid in the second pipeline downstream of the pump Pu.
    According to another embodiment, determining a first fluid flow comprises normalizing the fluid flow.
    According to a further embodiment, the method comprises comparing the formerthe fluid flow with the second fluid flow for a plurality of time periods At narthe dosing unit is Open, determine an average error parameter based on the comparisons, and adjust the opening time of the dosing unit based on the average error parameter.
    According to one embodiment, the method comprises periodically adjusting the opening time forthe dosage unit based on the error parameter. According to another embodiment, the method comprises continuously adjusting the opening time of the dosing unit based on the error parameter.
    According to a third aspect, the purpose is achieved at least in part by oneexhaust after-treatment system comprising a dosing system arranged to dose a reducing agent comprising urea.
    According to a fourth aspect, the object is achieved at least in part by a vehicle whichcomprises an exhaust after-treatment system comprising a dosing systemwhich is arranged to dose a reducing agent comprising urea.7According to a fifth aspect, the object is at least partially achieved by a computer program, P, wherein said computer program P includes program code for causing a control unit or other computer connected to the control unit to perform the steps according to the method.
    According to a sixth aspect, the object is achieved at least in part by onecomputer program product comprising a program code stored on a computer readable non-volatile medium for performing the method steps according to any of the embodiments herein, when said program code is executed on the control unit or other computer connected to the control unit.
    Preferred embodiments are described in the dependent claims and in the detailed description.
    Brief description of the accompanying figuresIn the following, the invention will be described with reference to the appended onesthe clocks, of which:Fig. 1 shows a vehicle with an exhaust after-treatment system.
    Fig. 2 shows a dosing system according to an embodiment as part of the exhaust after-treatment system in Fig. 1.
    Fig. 3 shows a flow chart according to an embodiment of the method.
    Fig. 4 illustrates a relationship between the pressure on the suction side and the flow from the dosing unit.
    Detailed Description of Preferred Embodiments of the InventionFig. 1 schematically illustrates a vehicle 1 in the form of a truck with a frame 2 andan engine 3. From the engine 3, exhaust gases are led via an exhaust pipe 4a to an exhaust after-treatment system 5 for purification. Purified exhaust gases are then discharged to the environment via an exhaust pipe 6 from the exhaust after-treatment system 5. The vehicle 1 is shown in the form of a truck without slack, but can instead be a bus, awork vehicle or a car. The engine 3 can be a diesel engine or anotherengine whose exhaust gases must be purified from NON.8Fig. 2 shows a part of the exhaust after-treatment system 5. The exhaust after-treatment system 5 comprises a catalyst 7, for example an SCR catalyst, for purifying the exhaust gases from NOx. The catalyst 7 may be located on the upstream catalyst 7 which are arranged to purify the exhaust gases.from larger particles before the exhaust gases reach the catalyst 7. The exhaust pipe 6 then leadsemit the purified exhaust gases into the environment. As illustrated in Fig. 5a, a metering unit 12 is arranged in a pipeline 4b upstream of the catalyst 7, so that the metering unit 12 can inject a fluid in the form of a reducing agent comprising urea into the exhaust gases in the exhaust pipeline 4b before reaching the catalyst 7.
    A control unit 13 is arranged to control the amount of fluid to be dosed thanthe dosing unit 12 by sending a control signal s1 to the dosing unit 12. The control signal s1 contains data on the opening time and closing time of the dosing unit 12, for example in the form of one or more time periods .t.
    The dosing unit 12 retrieves its fluid from a container 8 of intended fluidto be dosed. According to an embodiment, the container 8 is a closed container with a deaeration valve (not shown) and which is connected to a supply line (not shown) in order to be able to fill the container 8 with more fluid. A pump Pu is arranged to pump fluid from the container 8 via a first pipeline 9. The pump Pn may, for example, bea diaphragm pump. The dosing unit 12 is connected downstream of the pump Pu via a second pipeline 11. A detector unit 16 is arranged to detect a pressure P2 in the fluid in the second pipeline 11 downstream of the pump Pu and sends the detected pressure P2 to the control unit 13. The pump Pu is in turn arranged to maintain a desired pressure in the fluid in the second pipeline 11 downstreampump Pu i based on the detected pressure P2. The control unit 13 may, for example, be arranged to send a control signal s2 to the pump Pu which indicates an increase or decrease of the pump speed of the pump Pu based on the detected pressure P2, so that the pressure P2 becomes the desired pressure. The desired pressure is, for example, between 8-12 bar, for example 9 bar. Alternatively, the pump canPu be arranged to receive the pressure P2 and directly regulate the pump Pu against the desired pressure. The dosing system is thus arranged to regulate the pump speed of the pump Pu so that the pressure P2 becomes the desired pressure within9an interval !. The pump Pu then sucks up fluid from the container 8 in the first pipeline 9, which is then passed on through the second pipeline 11 to the dosing unit 12. When the dosing unit 12 is opened, fluid is injected into the exhaust pipe 4b. The pressure then decreases in the pipeline 11, which startspump Pn. The pump Pn pairs the fluid in the container 8 through the first pipeline 9. A metering of the dosing unit 12 is thus reflected in the first pipeline 9 since the flow in the first pipeline 9 changes when the dosing unit 12 is opened or closed.
    A detector unit G which supplies the amount of NOx is arranged upstream of the dosing unit 12 in the exhaust pipe 4b for all the supply of the amount of NOx in the exhaust gases before the catalyst 7 and before the injection with the dosing unit 12 takes place. An additional detector unit G which supplies the amount of NOx is arranged downstream of the catalyst 7 to supply the amount of NOx in the exhaust gases afterthe exhaust gases have been treated in the catalyst 7 under the influence of the reducing agent.
    The detector units G generate a signal d1, d2 each indicating the amount of NOx and which is sent to the control unit 13. The control unit 13 is arranged to receive the signals d1, d2 and to determine what amount of fluid needs to be dosed into the exhaust gases for the exhaust gases to be purified to a unwanted level. Based on whichamount of fluid to be dosed, the control unit 13 determines an opening time ft for the dosing unit 12. The control unit 13 can generate a control signal s1 to the dosing unit 12 which indicates the opening time .t, for example as an opening time and a closing time.
    The dosing unit 12 may, for example, comprise or consist of a valve,for example, a one-way valve, with a tipped bearing and a closed bearing. The valve can be electrically controlled.
    The dosing system comprises an additional detector unit 17 which is arrangeddetecting a fluid parameter (f) indicating a fluid flow in the firstpipeline 9 uppstronns punnpen Pu. The detector unit 17 is further arranged to generate a fluid signal indicating the fluid parameter cp, and send it tothe control unit 13. According to an embodiment, the detector unit 17 is arranged to detect a fluid parameter 9 which is a pressure parameter P1. The detector unit 17 may, for example, be a pressure detector. According to another embodiment, the detector unit 17 is arranged to detect a fluid parameter 9 which is oneflow parameter. The detector unit 17 may be, for example, a river detector. The control unit 13 is arranged to receive the fluid parameter 9 and to determine a first fluid flow in the first conduit 9 upstream of the punch pin Pu based on the fluid parameter 9. If the fluid parameter 9 is a pressure parameter P1, the pressure parameter can be converted to a flow parameter by a relationship which isedge of the control unit 13, and a first fluid flow is determined. If the fluid parameter9 is a flow parameter, a first fluid flow can be directly determined.
    The control unit 13 is further arranged to compare the first fluid flow in the first pipeline 9 upstream of the pump Pu with a second fluid flow Thanthe dosing unit 12 during the time period At. The control unit 13 has as beforeexplained exactly the amount of fluid to be dosed. Since the desired pressure in the second pipeline 11 is maintained through the punch pin Pu, the flow of fluid from the dosing unit 12, called the second fluid flow, should ideally be constant and predetermined. By opening the dosing unit 12 for a certain time medt with a desired pressure on the fluid, the desired amount can then be dosed. Control unit 13have access to calibrated relationships between the amount of fluid dosed,opening time and pressure of the fluid. The control unit 13 thus has access to a predetermined value of the second fluid flow under the desired pressure. The predetermined value of the second fluid flow thus varies with the pressure of the fluid. These predetermined and / or calibrated values can, for example, be phasedfrom the manufacturer.
    The control unit 13 is further arranged to determine an error parameter based on the result of the comparison of the first flow and the second flow of fluid. The comparison between the first and second floods may show a difference in floods.
    The difference in flood can be converted to If the first flood is smaller than the secondthe flow, sa is not dosed sufficiently with fluid. The opening hours must then be required.
    If the first river is larger than the second river, too much fluid is dosed.11The opening hours must then be shortened. If the first river is substantially as large as the second river, then the correct amount of fluid is dosed and the opening time does not need others. The error parameter may, for example, indicate a difference in flow or a difference in the amount of fluid. The control unit 13 is arranged to determine how muchthe opening time needs to be adjusted based on the error parameter to removethe difference between the first river and the second river, or the difference in the amount of fluid. The control unit 13 may be arranged to generate a signal s3 indicating the error parameter. The signal s3 can for instance be received by an indicating unit 18, which is arranged to indicate to, for example, the meter that the dosing is incorrect.or enter the error parameter itself, in response to the received signal s3.
    The indication can be done visually, audibly and / or tactilely. Alternatively, the error parameter can be sent to a central unit (not shown), for example in a farm, for further analysis and / or action. The control unit 13 may further be arranged to determine an adjusted opening time based on the current opening time and how muchopening hours need to be changed. The control unit 13 may also be arranged to generate a control signal s1 which indicates at least one opening time for the dosing unit 12 adjusted in accordance with the error parameter.
    According to one embodiment, the control unit 13 is arranged to compare the firstthe fluid flow with the second fluid flow for a plurality of time periods At narthe dosing unit 12 is open, determining an average error parameter based on the comparisons, and generating a signal indicating the average error parameter. The control unit 13 may also be arranged to generate at least one adjusted opening time for the dosing unit 12 based on the averageerror parameter.
    The control signal s1 can indicate that the opening time should be adjusted periodically. According to one embodiment, the control unit can be arranged to adjust the opening time at selectedtimes, for example, every 5 minutes, every 10 minutes, once an hour, whenthe vehicle is still, etc. According to another embodiment, the control unit may bearranged to determine an average error parameter and adjust the opening time at selected times, for example every 5 minutes, every 10 minutes, once an hour,12when the vehicle is stationary etc based on the average fault parameter. The control signal s1 can indicate instead that the opening time is to be adjusted continuously.
    Then fault parameters and adjusted opening hours can be determined continuously.
    According to one embodiment, a third lead (not shown) may be connected betweenthe second pipeline 11 and the container 8. Since the dosing unit 12 is not open, the pump Pn can pump fluid back to the container 8 so that a continuous flow arises in the pipelines. There is then always a pressure in the second pipeline 11.
    Vehicle 1 communicates internally between its various units etc. through, for example, a bus, for example a CAN bus (Controller Area Network) which uses a message-based protocol. Examples of other communication protocols that can be used are TTP (Time-Triggered Protocol),Flexray et al. In this way, the signals and data described here can be exchanged betweendifferent units in the vehicle 1. For example, signals and data can instead be transmitted wirelessly between the different units.
    The control unit 13 comprises a processor unit 14 and a memory unit 15 which isconnected to the processor unit 14. On the memory unit 15 there is a computer program Pstored, which can cause the control unit 13 to perform the steps according to the method described herein. According to one embodiment, the memory unit 15 is part of the processor unit 14. The processor unit 14 may be constituted by one or more CPUs (Central Processing Unit). The memory unit 15 may comprise a non-volatile memory,for example, a flash memory or a RAM (Random Access Memory). The memory unit 15 includes instructions for shaping the processor unit 14 to execute a number of steps which will be explained with reference to the flow chart in Fig. 3.
    Fig. 3 shows a flow chart of a method for monitoring the amount of fluid whichis dosed by the dosing system in Fig. 2. First, a time period Att is determined during which the dosing unit 12 is open (A1). This time period is known13the control unit 13, since the control unit 13 determines the time period based on the amount of fluid to be dosed. Thus, according to one embodiment, At is a time period determined by the control unit 13. The fluid parameter p is detected upstream of the pump Pu during the time period At (A2), and a first is determined.fluid flow in the first pipeline 9 upstream of the pump Pu (A3). Fluid parametersis, for example, a pressure parameter. Then the first fluid flow in the first pipeline 9 upstream of the pump Pu is compared with a second fluid flow fromthe dosing unit 12 during the time period (t (A4). As explained, the second fluid flow is an edge flow due to the pressure P2. The second fluid flow can thusconsists through an edge true band, or through a table stored inmemory unit 15. An error parameter is determined based on the result of the comparison (A5). As a subsequent step, the opening time of the dosing unit 12 can be adjusted according to the error parameter. The method may include periodically adjusting the opening time of the dosage unit based on the error parameter and / orcontinuously adjust the opening time of the dosing unit based onerror parameter.
    According to one embodiment, the method comprises comparing the first fluid flow withthe second fluid flow for a number of time periods At when the dosing unit isopen and determine an average error parameter based on the comparisons. The opening time of the dosing unit can then be adjusted based on the average error parameter. The opening time can then be adjusted from time to time, ie with nnellanrunn nnellan times the adjustment takes place.
    Fig. 4 illustrates in a diagram the pressure P1 in the first pipeline 9 obtained witha differential pressure sensor, superimposed on the second fluid flow (has B1) from the dosing unit 12 for a period of time. In this diagram, therefore, the pressure P1 has not been made on-in to a flood, and has been used to illustrate the principle. The pressure P1 is also called the pressure P1 on the "suction side", because the pump Pn sucks up the fluid fromthe container 8. As can be seen in the diagram, the pressure P1 of others on the suction side is linearwith an Okande second flu idflOde Bl. The dosing system is has calibrated to give one14other fluid flow which is linear towards the period time until the maximum dosing takes place at a given working pressure P2. Dosed amounts may, however, differ for different dosage units 12 and may also differ over time. In order to be able to accommodate the changes of the pressure P1 on the suction side with the second fluid flow, the pressure P1 is converted to a firstfluid flow for it to be the same quantity as the other fluid flow. If necessarythe fluid flow in the first pipeline 9 can also be normalized before the first fluid flow is determined.
    The present invention is not limited to those described abovethe embodiments. Various alternatives, modifications and equivalents can be used.
    Therefore, the above-mentioned embodiments do not limit the scope of the invention, which is defined by the appended claims.
    权利要求:
    Claims (25)
    [1]
    A container (8) of fluid for dosing; - a pump Pu arranged to pump fluid Than container (8) via a first pipeline (9); A dosing unit (12) which is connected downstream of the pump Pu via a second pipeline (11) and which is arranged to dose the fluid; A control unit (13) arranged to control the amount of fluid to be dosed from the dosing unit (12), characterized in that the dosing system comprises a detector unit (17) arranged to detect a fluid parameter p indicating a fluid flow in the first pipeline ( 9) upstream of the pump Pu and generating a fluid signal indicating the fluid parameter p, the control unit (13) is further arranged to: - determine a time period undert during which the dosing unit (12) is open; 4. determining a first fluid flow in the first pipeline (9) upstream of the pump Pu; 5. comparing the first fluid flow in the first pipeline (9) to the pump Pu with a second fluid flow Than dosing unit (12) during the time period ;t; 6. determine an error parameter based on the result of the comparison; 7. generate a signal indicating the error parameter.
    [2]
    The dosing system according to claim 1, wherein the control unit (13) is arranged to generate a control signal indicating at least one opening time of the dosing unit (12) which is adjusted in accordance with the error parameter.
    [3]
    The dosing system according to claim 1 or 2, wherein the detector unit (17) is arranged to detect a fluid parameter p which is a pressure parameter. 16
    [4]
    The dosing system according to any one of the preceding claims, wherein the control unit is arranged to determine the time period .t.
    [5]
    The dosing system according to any one of the preceding claims, wherein the control unit (13) is adapted to determine the second fluid flow.
    [6]
    A dosing system according to any one of the preceding claims, comprising a further detector unit (16) arranged to detect a pressure P2 in the fluid downstream of the pump Pu, the pump Pu being arranged to maintain a desired pressure in the fluid in the second pipeline. downstream pump Pu.
    [7]
    The dosing system according to any one of the preceding claims, wherein the control unit (13) is arranged to compare the first fluid flow with the second fluid flow for a plurality of time periods. When the dosing unit (12) is open, determine an average error parameter based on the comparisons, and generate a signal indicating the average error parameter.
    [8]
    The dosing system according to claim 7, wherein the control unit (13) is arranged to generate a control signal indicating at least one adjusted opening time for the dosing unit (12) based on the average error parameter.
    [9]
    A dosing system according to any one of the preceding claims, wherein the control unit (13) is arranged to generate a control signal to the dosing unit (12) for periodically adjusting the opening time of the dosing unit (12) based on the error parameter.
    [10]
    The dosing system according to any one of claims 1 to 8, wherein the control unit (13) is arranged to generate a control signal to the dosing unit (12) for continuously adjusting the opening time of the dosing unit (12) based on the error parameter. 17
    [11]
    A method of monitoring the amount of fluid dispensed by a dispensing system, the dispensing system comprising a container (8) of fluid to be dispensed, a pump Pu arranged to pump fluid from the container (8) via a first conduit (9). ), a dosing unit (12) which is connected downstream of the pump Pu via a second pipe (11) and which is arranged to dose the fluid, a control unit (13) which is arranged to regulate the amount of fluid to be dosed Than dosing unit (12), the dosing system also comprises a detector unit (17) arranged to detect a fluid parameter cp indicating a fluid flow in the first pipeline (9) upstream of the pump Pu, the method comprising 1. determining a time period Att during which the dosing unit (12) is Open; 2. detect the fluid parameter cp upstream of the pump Pu during the time period ;t; Determining a first fluid flow in the first pipeline (9) upstream of the pump Pu; 4. comparing the first fluid flow in the first pipeline (9), pump pump Pu with a second fluid flow Than dosing unit (12) during the time period ;t; 5. determine an error parameter based on the result of the comparison.
    [12]
    The method of claim 11, comprising adjusting the opening time of the dosing unit (12) according to the error parameter.
    [13]
    The method of claim 11 or 12, wherein the fluid parameter (f) is a pressure parameter.
    [14]
    The method according to any one of claims 11 to 13, wherein At is a time period determined by the control unit (13). 18
    [15]
    The method of any of claims 11 to 14, wherein the second fluid flow is determined by the control unit.
    [16]
    The method according to any one of claims 11 to 15, wherein the dosing system comprises an additional detector unit (16) arranged to detect a pressure P2 in the fluid downstream of the pump Pu, the pump Pu being arranged to maintain a desired pressure in the fluid in the second pipeline downstream of the pump Pu.
    [17]
    The method of any of claims 11 to 16, wherein determining a first fluid flow comprises normalizing the fluid flow.
    [18]
    The method of any of claims 11 to 17, comprising comparing the first fluid flow with the second fluid flow over a plurality of time periods when the dosage unit is open and determining an average error parameter based on the readings.
    [19]
    The method of claim 18, comprising adjusting the opening time of the dosage unit based on the average error parameter.
    [20]
    The method of any of claims 11 to 19, comprising periodically adjusting the opening time of the dosage unit based on the error parameter.
    [21]
    The method of any of claims 11 to 19, comprising continuously adjusting the opening time of the dosage unit based on the error parameter.
    [22]
    An exhaust after-treatment system (5) comprising a dosing system (12) according to any one of claims 1 to 10 which is arranged to dose a reducing agent comprising urea. 19
    [23]
    Vehicle (1) son comprising an exhaust aftertreatment system (5) according to claim 22.
    [24]
    Computer program, P, wherein said computer program P comprises program code for causing a control unit (13), or other computer connected to the control unit (13), to perform the steps according to any one of claims 11 to 21.
    [25]
    A computer program product comprising a program code stored on a computer readable non-volatile medium for performing the method steps according to any one of claims 11 to 21, when said program code is executed on the control unit (13) or other computer connected to the control unit (13). 1/2
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    同族专利:
    公开号 | 公开日
    SE538383C2|2016-06-07|
    DE102015005245A1|2015-10-29|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    DE102008001789A1|2008-05-15|2009-11-19|Robert Bosch Gmbh|Method for operating a metering valve and device for carrying out the method|
    DE102009023325B4|2008-12-10|2012-01-26|Continental Automotive Gmbh|Method for adapting the injection of injection agent in an injection system|
    DE102011078870A1|2011-01-20|2012-07-26|Robert Bosch Gmbh|Method for monitoring functions of dosing system, particularly metering system for selective catalytic reduction catalyst, involves clocked dosing of liquid medium by feed pump and metering valve|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    SE1450493A|SE538383C2|2014-04-25|2014-04-25|Dosage system and method for monitoring the amount of fluid dosed by the dosing system|SE1450493A| SE538383C2|2014-04-25|2014-04-25|Dosage system and method for monitoring the amount of fluid dosed by the dosing system|
    DE102015005245.4A| DE102015005245A1|2014-04-25|2015-04-24|Metering system and method for monitoring the amount of fluid metered by the metering system|
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