air conditioning unit

专利摘要:
AIR CONDITIONING DEVICE. The present invention relates to an air conditioning apparatus (10) that includes a heat source unit (20), use units (40, 50, 60) and a controller (80). The heat source unit (20) has a compression mechanism (21), a heat exchanger on the heat source side (23) that functions at least as an evaporator, and an expansion valve on the heat source side (38) . The use units (40, 50, 60) have heat exchangers on the use side (42, 52, 62) that work at least as capacitors, and expansion valves on the use side (41, 51, 61). The controller (80) regulates the degree of opening of the expansion valve on the heat source side (38) based on the degrees of openings of the expansion valves on the use side (41, 51, 61).
公开号:BR112013002731B1
申请号:R112013002731-2
申请日:2011-07-21
公开日:2021-01-05
发明作者:Kousuke Kibo；Shinichi Kasahara
申请人:Daikin Industries, Ltd.；
IPC主号:

专利说明:

Technical field
[0001] The present invention relates to an apparatus for air conditioning. Background art
[0002] In conventional practice there have been air conditioning devices that have a refrigerant circuit in which two expansion valves are connected in series, as shown in Patent Literature 1 (Japanese Open Patent Application number 2002-39642). In this air conditioning unit, an outdoor expansion valve is placed in an outdoor unit, an indoor expansion valve is placed in an indoor unit and these valves are connected, thereby forming a refrigerant circuit, in which two expansion valves are connected in series. Summary of the invention Technical problem
[0003] In this type of conventional air conditioning device, the outer expansion valve and the inner expansion valve are controlled separately to achieve target values, and the degree of depressurization in the refrigeration cycle is established by the total amount of depressurization achieved by outer expansion valve and inner expansion valve together. Therefore, when the outer expansion valve and the inner expansion valve are controlled separately, sometimes the amount of depressurization by the outer expansion valve is large and the amount of depressurization by the inner expansion valve is small, even if the reduced pressure in the total reaches target value.
[0004] In such cases, the refrigerant in a liquid refrigerant communication tube that flows from the indoor unit to the outdoor unit quickly goes into a two-phase gas-liquid state, particularly during an air heating operation. In addition, the wet vapor quality of the refrigerant in the liquid refrigerant communication tube changes enormously depending on the state of operation. Such factors inhibit the interior of the liquid refrigerant communication tube from being filled with liquid refrigerant, resulting in excess refrigerant since the amount of refrigerant is selected based on the air cooling operation that requires a greater amount of refrigerant than than the air heating operation. Therefore, there is a lot of refrigerant that cannot be evaporated in the evaporator, and in cases where the accumulator is small and / or there appears to be an overfill of refrigerant, there is a risk that the accumulator will overflow and cause wet compression.
[0005] In a multiple system in which a plurality of indoor units are connected to a single outdoor unit, the opening degree of the indoor expansion valve is not completely closed but set to open slightly to prevent liquid refrigerant from accumulating in the heat exchanger. interior heat during the thermal state or stays off. With such an air conditioning unit, in such a case that the thermal load of an indoor unit is small and in an off-off state and the thermal load of another indoor unit is large, when the amount of depressurization by the external expansion valve is extremely small, the degrees of openness in all indoor expansion valves are small despite the thermal load of the indoor units, to ensure the amount of depressurization. Therefore, even if the thermal loads differ between the plurality of indoor units, it is difficult to create a difference in the degrees of opening of the indoor expansion valves according to the dimensions of the thermal loads of the indoor units. This is because or depending on the interior expansion valve there are variations in the relationship between degrees of opening and quantities of depressurization of interior expansion valves due to individual differences from the interior expansion valves, or because the dimensions of the interior expansion valves differ according to the dimensions of the rated capacities of the indoor units, and when the degrees of openness of the interior expansion valves are extremely small or approximately so (hereinafter referred to as low openness state), it is difficult to precisely control the quantities of depressurization in the interior expansion valves. In the low-open state, there is a large change in refrigerant flow by changing the opening level of the unit pulse, and it is therefore difficult to precisely control the quantities of depressurization, as described above. Therefore, there are cases in which, as a result, too much refrigerant flows through an indoor unit that has a small thermal load. So there is a risk that it will not be possible to use energy efficiently.
[0006] An object of the present invention is to provide an air conditioning apparatus that has two expansion valves connected in series, and in which a compressor can be protected, and energy can be conserved. Solution to the problem
[0007] An air conditioning apparatus according to a first aspect of the present invention comprises a heat source unit, units of use and a controller. The heat source unit has a compression mechanism, a heat exchanger on the heat source side that works at least as an evaporator, and an expansion valve on the heat source side. The use units have heat exchangers on the use side that function at least as condensers, and expansion valves on the use side. The controller regulates the degree of openness of the expansion valve on the heat source side based on the degree of openness of the expansion valves on the use side.
[0008] Therefore, it is possible to adjust the balance between the amount of depressurization by means of the expansion valve on the side of the heat source and the amounts of depressurization by means of the expansion valves on the side of use. Therefore, excess refrigerant can be prevented from occurring in the refrigerant circuit, and wet compression can be prevented from occurring in the compressor.
[0009] It is possible to adjust the balance between the amount of depressurization by means of the expansion valve on the side of the heat source and the amounts of depressurization by means of the expansion valves on the side of use, even when there is a plurality of units of use , for example. Therefore, the amount of depressurization through the expansion valve on the heat source side can be prevented from being extremely small, and it is easy to achieve a balance on the use side expansion valves between use units that have a small load. required and units of use that have a large required load. A suitable ratio for each required charge can therefore be achieved between the amount of refrigerant flowing into units of use that have a small required charge and units of use that have a large required charge. An excessive amount of refrigerant can therefore be prevented from flowing to units of use that have a small required charge, and energy can be conserved.
[00010] An apparatus for air conditioning according to a second aspect of the present invention is the apparatus for air conditioning according to the first aspect, in which the heat source unit also has an accumulator on the intake side of the cooling mechanism. compression.
[00011] Therefore, even if an excess of refrigerant is present in the refrigerant circuit, the refrigerant can be accumulated in the accumulator. Therefore, liquid compression can be prevented from occurring in the compression mechanism.
[00012] An apparatus for air conditioning according to a third aspect of the present invention is the apparatus for air conditioning according to the first or second aspect, in which the controller regulates the degree of opening of the expansion valves on the side of use during an air heating operation, so that the degree of subcooling at the outputs of the heat exchangers on the side of use reaches a degree of target value subcooling.
[00013] Thus, even if the controller is performing a control in order to regulate the opening degrees of the expansion valves on the side of use during an air heating operation so that the degrees of sub-cooling at the outputs of the air exchangers use side heat reaches a degree of subcooling of target value, the degree of opening of the expansion valve on the heat source side is regulated based on the degree of opening of the expansion valves on the use side and is, therefore, it is possible to adjust the balance between the amount of depressurization by means of the expansion valve on the side of the heat source and the amounts of depressurization by means of the expansion valves on the side of use.
[00014] An air conditioning apparatus according to a fourth aspect of the present invention is the air conditioning apparatus according to the third aspect, in which there are a plurality of units of use. The controller establishes the degree of subcooling target value for each of the utilization units according to the load required for each of the utilization units.
[00015] Thus, even if there is a plurality of units of use and the controller is carrying out a control in order to regulate the degrees of opening of the expansion valves on the side of use during an air heating operation so that the degrees of subcooling at the heat exchanger outputs on the utilization side reach a degree of subcooling target value, it is possible to regulate the balance between the amount of depressurization by means of the expansion valve on the heat source side and the quantities of depressurization by means of the expansion valves on the side of use. Therefore, the amount of depressurization by means of the expansion valve on the heat source side can be prevented from being extremely small, and it is easy to achieve a balance on the use side expansion valves between the use units that have a small required load and units of use that have a large required load. A suitable ratio for each required charge can therefore be achieved between the amount of refrigerant flowing into units of use that have a small required charge and units of use that have a large required charge. An excessive amount of refrigerant can therefore be prevented from flowing to units of use that have a small required charge, and energy can be conserved.
[00016] An apparatus for air conditioning according to a fifth aspect of the present invention is the apparatus for air conditioning according to the fourth aspect, in which the controller regulates the expansion valves on the side of use when the units of use they are in an off state, so the valves are not fixed in a completely closed state, and a coolant flow is ensured.
[00017] In the appliance for air conditioning according to the fifth aspect, even if the controller is carrying out a control in order to regulate the expansion valves on the side of use when the units of use are in the off state, so that the valves are not fixed in the completely closed state and a coolant flow is ensured, the balance is regulated between the amount of depressurization by means of the expansion valve on the heat source side and the amounts of depressurization by means of the expansion valves on the side of use. The phrase "control to regulate the expansion valves on the side of use so that the valves are not fixed in the completely closed state and a coolant flow is ensured" used here, refers to control to regulate the expansion valves on the side of use use for extremely small degrees of openness, control to repeatedly place the expansion valves on the side of use in the completely closed state, and an intermittent open state, and / or the like, for example.
[00018] As described above, it is generally difficult to precisely control the amounts of depressurization in the expansion valves on the side of use when the interior expansion valves have low degrees of openness. Even if the expansion valves on the side of use are repeatedly alternating between the completely closed state and an open state by means of intermittent control, it is difficult to precisely control the quantities of depressurization in the expansion valves on the side of use.
[00019] Therefore, even in cases where the expansion valves on the side of use have extremely small degrees of openness and / or cases in which the expansion valves on the side of use are repeatedly switched between completely closed state and an open state by means of intermittent control, in which it is particularly difficult for the degrees of openness of the expansion valves on the side of use to precisely control the quantities of depressurization, the amount of depressurization by means of the expansion valve on the heat source side can be prevented from becoming extremely small, and it is possible to easily achieve a balance on the use side expansion valves between units of use in the off state that have a small required load and units of use that have a large required load. Therefore, a suitable ratio for each required charge can be achieved between the amount of refrigerant that flows to use units in the off state that have a small required charge and use units that have a large required charge. An excessive amount of refrigerant can thereby be prevented from flowing to units of use that have a small required charge, and energy can be conserved.
[00020] An air conditioning device according to the sixth aspect of the present invention is the air conditioning device according to the fourth or fifth aspect, in which the controller regulates the degree of opening of the source side expansion valve of heat based on a representative degree of opening of the expansion valves on the use side of the use units.
[00021] Therefore, the degree of opening of the expansion valve on the heat source side can be regulated even when there are a plurality of use units and a plurality of expansion valves on the use side.
[00022] An apparatus for air conditioning according to the seventh aspect of the present invention is the apparatus for air conditioning according to the sixth aspect, in which the controller uses the maximum degree of openness between the degrees of openness of the valves. expansion of the utilization side of the utilization units as the representative degree of openness.
[00023] Therefore, the degree of opening of the expansion valve on the heat source side can be regulated even when there are a plurality of use units and a plurality of expansion valves on the use side.
[00024] An apparatus for air conditioning according to the eighth aspect of the present invention is the apparatus for air conditioning according to the seventh aspect, in which the controller corrects the opening degrees of the expansion valves on the side of use for each of the units of use based on the specifications of the unit of use to which the expansion valve on the side of use belongs, and uses as a representative degree of opening the maximum degree of opening between the degrees of opening of the expansion valves on the side of use use after correction in the units of use.
[00025] Generally, when the units of use have different specifications, the quantities of depressurization relative to the degrees of opening of the expansion valves on the side of use are different. Specifically, there are cases in which the degrees of openness of the expansion valves on the side of use and quantities of depressurization through the expansion valves on the side of use are not proportional. Therefore, when the expansion valve on the heat source side is regulated based only on the degrees of openness of the expansion valves on the use side, there is a risk that the expansion valve on the heat source side will be regulated based on different values. the actual quantities of depressurization by means of the expansion valves on the side of use.
[00026] In the air conditioning apparatus in accordance with the eighth aspect, the controller corrects the degrees of openness of the expansion valves on the use side of the plurality of use units for each use unit based on the specifications of the use unit to which the use-side expansion valve belongs. The controller then uses as the representative opening degree the maximum opening degree between the opening degrees of the expansion valves on the side of use after correction. The term "use unit specifications" refers to a relationship between a specific flow rate based on the refrigerant flow required to achieve the rated capacity of the use units under predetermined conditions, and the expansion valve openings on the use side of the units. of use.
[00027] This is because the degrees of openness of the expansion valves on the side of use are corrected based on the specifications of the units of use and the maximum degree of openness between the degrees of openness of the expansion valves on the side of use after of the correction is used as the representative degree of opening, the representative degree of opening and the actual quantities of depressurization by the expansion valves on the side of use can be made to have an approximately proportional relationship. Therefore, even if the units of use have different specifications, the degree of openness of the expansion valve on the heat source side can be adjusted based on a value close to the actual quantities of depressurization through the expansion valves on the use side, and the amount of depressurization by means of the expansion valve on the heat source side can be regulated more precisely.
[00028] An air conditioning apparatus according to the ninth aspect of the present invention is the air conditioning apparatus according to the seventh or eighth aspect, in which the controller corrects the opening degrees of the expansion valves on the side of use for each unit of use based on the installation conditions of the unit of use to which the expansion valve on the side of use belongs and uses as the representative degree of opening the maximum degree of opening between the degrees of opening of the valves of expansion on the use side after correction in the use units.
[00029] Generally, when a plurality of use units are installed, the refrigerant communication tubes from the use units to the heat source unit have different tube lengths and / or tube diameters, for example, in each unit of use. Specifically, the pressure loss in the refrigerant communication tube differs in each unit of use.
[00030] In the air conditioning unit in accordance with the ninth aspect, the controller corrects the degrees of openness of the expansion valves on the use side of the plurality of use units for each use unit based on the installation conditions of the unit of use to which the expansion valve on the side of use belongs. The controller then uses as the representative opening degree the maximum opening degree between the opening degrees of the expansion valves on the side of use, after correction. The term "installation conditions for the units of use" refers to the tube lengths and tube diameters of the refrigerant communication tubes from the heat source unit (or from beyond the branch point of the refrigerant communication tubes ) to the units of use.
[00031] This is because the opening degrees of the expansion valves on the side of use are corrected based on the installation conditions of the units of use, and the maximum opening degree between the opening degrees of the expansion valves on the side of use after correction is used as the representative degree of opening, the representative degree of opening and the actual quantities of depressurization by means of the expansion valves on the side of use can be made to have an approximately proportional relationship. Therefore, even if the units of use have different installation conditions, the degree of opening of the expansion valve on the heat source side can be adjusted based on a value close to the actual quantities of depressurization through the expansion valves on the heat source side. utilization, and the amount of depressurization by means of the expansion valve on the heat source side can be regulated more precisely.
[00032] An air conditioning apparatus according to a tenth aspect of the present invention is the air conditioning apparatus according to the sixth aspect, in which the controller uses the average opening degree of the expansion valves on the side of use units of use as the representative degree of openness.
[00033] Therefore, the degree of opening of the expansion valve on the heat source side can be regulated even when there are a plurality of use units and a plurality of expansion valves on the use side.
[00034] An air conditioning apparatus according to an eleventh aspect of the present invention is an air conditioning apparatus according to any one of the sixth through the tenth aspects, in which the controller regulates the degree of opening of the air valve. expansion of the heat source side so that the representative degree of opening approaches a predetermined degree of opening.
[00035] Thus, by adjusting the degrees of opening of the expansion valves on the side of use to a predetermined degree of opening in advance, the balance between the quantities of depressurization by means of the expansion valves on the side of use and the amount of depressurization by means of The expansion valve on the heat source side can be adjusted to an optimum.
[00036] An air conditioning apparatus according to a twelfth aspect of the present invention is an air conditioning apparatus according to any one of the first to eleventh aspects, in which the controller makes the target value of the degrees of opening of the expansion valves on the side of use fluctuate according to an estimated system of refrigerant quantity status since the operating state, the target value being a reference to regulate the degree of opening of the source side expansion valve of heat.
[00037] In the air conditioning unit according to the twelfth aspect, the controller causes the target value of the opening degrees of the expansion valves on the side of use to fluctuate according to whether the state of the refrigerant quantity of the system that is the amount of refrigerant in the refrigerant circuit is in a tendency of an excess or an insufficient trend in the refrigerant circuit, for example, the target value being a reference to regulate the degree of opening of the source side expansion valve of heat. For example, if the status of the amount of refrigerant in the refrigerant circuit is a tendency to excess, the answer is to increase the target value of the opening degrees of the expansion valves on the side of use being referenced, and if the status of the amount of refrigerant in the refrigerant circuit is a tendency of an insufficiency, the answer is to reduce the target value of the opening degrees of the expansion valves on the side of use being referenced.
[00038] Therefore, when the state of the amount of refrigerant in the refrigerant circuit is in a trend of an excess, the refrigerant in the liquid refrigerant communication tube can be placed in a highly dense liquid state. Therefore, the amount of refrigerant retained in the liquid refrigerant communication tube can be increased as much as possible and operation is possible even when there is an excess of refrigerant.
[00039] When the state of the amount of refrigerant in the refrigerant circuit is in a trend of an insufficiency, the refrigerant in the liquid refrigerant communication tube can be placed in a two-phase low-density gas-liquid state. Therefore, the amount of refrigerant retained in the liquid refrigerant communication tube can be reduced, the reduced amount can be retained in the heat exchangers on the side of use, and operation is possible even when the refrigerant is insufficient. Advantageous effects of the invention
[00040] In the air conditioning apparatus according to the first aspect of the present invention, it is possible to adjust the balance between the amount of depressurization by means of the expansion valve on the heat source side and the amounts of depressurization by means of the expansion valves side of use. Therefore, excess refrigerant can be prevented from occurring in the refrigerant circuit and wet compression can be prevented from occurring in the compressor.
[00041] In the air conditioning apparatus according to the second aspect of the present invention, even if an excess of refrigerant is present in the refrigerant circuit, the refrigerant can be accumulated in the accumulator. Therefore, liquid compression can be prevented from occurring in the compression mechanism.
[00042] In the air conditioning apparatus according to the third aspect of the present invention, even if the controller is carrying out a control in order to regulate the opening degrees of the expansion valves on the side of use during an air heating operation so that the degrees of subcooling at the outputs of the heat exchangers on the utilization side reach the degree of subcooling target value, the degree of opening of the expansion valve on the heat source side is regulated based on the degrees of opening of the expansion valves on the side of use and it is therefore possible to regulate the balance between the amount of depressurization by means of the expansion valve on the source side of heat and the quantities of depressurization by means of the expansion valves on the side of use.
[00043] In the air conditioning apparatus according to the fourth aspect of the present invention it is possible to regulate the balance between the amount of depressurization by means of the expansion valve on the heat source side and the amounts of depressurization by means of the expansion valves side of use. Therefore, the amount of depressurization by means of the expansion valve on the heat source side can be prevented from being extremely small, and it is easy to achieve a balance on the use side expansion valves between the units of use that have a small required load. and units of use that have a large required load. Therefore, a suitable ratio for each required charge can be achieved between the amount of refrigerant that flows to utilization units that have a small required charge and utilization units that have a large required charge. An excessive amount of refrigerant can therefore be prevented from flowing to units of use that have a small required charge, and energy can be conserved.
[00044] In the air conditioning apparatus according to the fifth aspect of the present invention, even in cases where the expansion valves on the side of use have extremely small degrees of openness and / or cases in which the expansion valves on the side of use are repeatedly alternated between the completely closed state and an open state, by means of intermittent control which is particularly difficult for the degrees of opening of the expansion valves on the side of use to precisely control the quantities of depressurization, the amount of Depressurization by means of the expansion valve on the heat source side can be prevented from becoming extremely small and it is possible to easily achieve a balance on the expansion valves on the use side between units of use in the off state that have a small required load and units of use that have a large required load. Therefore, a suitable ratio for each required charge can be achieved between the amount of refrigerant that flows to use units in the off state having a small required charge and use units that have a large required charge. An excessive amount of refrigerant can thereby be prevented from flowing to units of use that have a small required charge, and energy can be conserved.
[00045] In the air conditioning apparatus according to the sixth aspect of the present invention, the degree of opening of the expansion valve on the heat source side can be regulated even when there are a plurality of use units and a plurality of use side expansion.
[00046] In the air conditioning apparatus in accordance with the seventh aspect of the present invention, the degree of opening of the expansion valve on the heat source side can be regulated even when there are a plurality of use units and a plurality of heating valves. use side expansion.
[00047] In the air conditioning apparatus according to the eighth aspect of the present invention, since the degrees of opening of the expansion valves on the side of use are corrected based on the specifications of the units of use, and the degree of opening maximum between the degrees of opening of the expansion valves on the side of use after correction is used as the representative degree of opening, the degree of representative opening and the actual quantities of depressurization by means of the expansion valves on the side of use can be made to have an approximately proportional relationship. Therefore, even if the utilization units have different specifications, the degree of opening of the expansion valve on the heat source side can be adjusted based on a value close to the actual quantities of depressurization through the expansion valves on the use side and the amount of depressurization by means of the expansion valve on the heat source side can be regulated more precisely.
[00048] In the air conditioning apparatus according to the ninth aspect of the present invention, since the opening degrees of the expansion valves on the side of use are corrected based on the installation conditions of the units of use and the degree of maximum opening between the degrees of opening of the expansion valves on the side of use after correction is used as the representative degree of opening, the degree of representative opening and the actual quantities of depressurization by means of the expansion valves on the side of use can be made to have an approximately proportional relationship. Therefore, even if the units of use have different installation conditions, the degree of opening of the expansion valve on the heat source side can be adjusted based on a value close to the actual quantities of depressurization through the expansion valves on the heat source side. utilization and the amount of depressurization by means of the expansion valve on the heat source side can be regulated more precisely.
[00049] In the air conditioning apparatus according to the tenth aspect of the present invention, the degree of opening of the expansion valve on the heat source side can be regulated even when there are a plurality of units of use and a plurality of air valves. use side expansion.
[00050] In the air conditioning apparatus according to the eleventh aspect of the present invention, adjusting the opening degrees of the expansion valves on the side of use to a predetermined opening degree in advance, the balance between the quantities of depressurization by means of of the expansion valves on the use side and the amount of depressurization by means of the expansion valve on the heat source side can be adjusted to an optimum.
[00051] In the air conditioning apparatus according to the twelfth aspect of the present invention, when the state of the amount of refrigerant in the refrigerant circuit is in a tendency of an excess, the refrigerant in the liquid refrigerant communication tube can be placed in a highly dense liquid state. Therefore, the amount of refrigerant retained in the liquid refrigerant communication tube can be increased as much as possible, and operation is possible even when there is an excess of refrigerant. When the status of the amount of refrigerant in the refrigerant circuit is in a trend of an insufficiency, the refrigerant in the liquid refrigerant communication tube can be placed in a low-density two-phase liquid-gas state. Therefore, the amount of refrigerant retained in the liquid refrigerant communication tube can be reduced, the reduced amount can be retained in the heat exchangers on the side of use, and operation is possible even when the refrigerant is insufficient. Brief Description of Drawings
[00052] Figure 1 is a schematic structural drawing of an air conditioning apparatus 10 according to an embodiment of the present invention; figure 2 is a control block diagram of the air conditioning apparatus 10, and figure 3 is a p-h graph (a Mollier diagram) of a refrigeration cycle of a refrigerant circuit 11. Description of modalities
[00053] The following is a description made with reference to the drawings of an embodiment of an air conditioning apparatus and the method of determining the amount of refrigerant according to the present invention. (1) Device configuration for air conditioning
[00054] Figure 1 is a schematic structural drawing of an air conditioning apparatus 10, according to an embodiment of the present invention. The air conditioning apparatus 10 is an apparatus used to heat and cool the air within a building or the like, performing a steam compression refrigeration cycle operation. The air conditioning apparatus 10 primarily comprises an outdoor unit 29 as a single heat source unit, indoor units 40, 50, 60, as a plurality of use units (three in the present embodiment), connected in series to the outdoor unit, and a liquid refrigerant communication tube 71 and a gas refrigerant communication tube 72, as refrigerant communication tubes that connect the outdoor unit 20 and the indoor units 40, 50, 60. Specifically, the refrigerant circuit vapor compression device 11 of the air conditioning apparatus 10 of the present embodiment is configured by connecting the outdoor unit 20, the indoor units 40, 50, 60, the liquid refrigerant communication tube 71 and the gas refrigerant communication tube 72. (1-1) Indoor units
[00055] The indoor units 40, 50, 60, are installed by being embedded in, or suspended from the ceiling of a room in a building or similar, or being mounted on the wall of a room. The indoor units 40, 50, 60 are connected to the outdoor unit 20 via the liquid refrigerant communication tube 71 and the gas refrigerant communication tube 72, and the indoor units are part of the refrigerant circuit 11.
[00056] Next, the configurations of indoor units 40, 50, 60 will be described. Since the indoor unit 40 has the same configuration as the indoor units 50, 60, only the indoor unit 40 configuration is described here, and for the indoor unit configurations 50, 60, numerals in the fifty and sixty are used instead numerals in the forties indicating the components of the indoor unit 40, and descriptions of these components are omitted.
[00057] The indoor unit 40 has, in a primary way, a refrigerant circuit on the inner side 11a that forms part of the refrigerant circuit 11, the indoor unit 50 has a refrigerant circuit on the inner side 11b and the indoor unit 60 has a refrigerant circuit on the inner side 11c. The inner side refrigerant circuit 11a primarily has an inner expansion valve 41 as an expansion mechanism and an inner heat exchanger 42 as a heat exchanger on the side of use. In this modality, indoor expansion valves 41, 51, 61 are provided as expansion mechanisms for indoor units 40, 50, 60, respectively, however this configuration is not the only possible option, and an expansion mechanism (which includes a expansion valve) can be supplied for outdoor unit 20, or indoor units 40, 50, 60, and outdoor unit 20 can be supplied for independent connection units.
[00058] In the present embodiment the interior expansion valve 41 is an electrical expansion valve connected to the liquid side of the interior heat exchanger 42 to perform operations such as regulating the refrigerant flow that flows through the interior side refrigerant circuit 11a, and this valve is also able to block the passage of refrigerant. In the present embodiment, when the opening degree of the inner expansion valve 41 is set to Maximo, the valve has a value of a maximum opening degree at which the valve opening pulse reaches a maximum. In the present embodiment, when the indoor unit 40 is in the off state the indoor expansion valve 41 is not fixed in the fully closed state, but is set to an extremely small degree of opening, in order to ensure a flow of refrigerant to prevent the liquid refrigerant builds up in the indoor heat exchanger. The term "extremely small degree of opening" used herein refers to the valve opening pulse that is set to a minimum predetermined value of a low degree of opening, which is not completely closed.
[00059] In the present mode, the interior heat exchanger 42 is a cross-fin type tube and fin heat exchanger, configured with a heat transfer tube and numerous fins. This heat exchanger functions as a refrigerant evaporator and cools the indoor air during an air cooling operation, and functions as a refrigerant condenser and heats indoor air during an air heating operation. In the present embodiment, the interior heat exchanger 42 is a fin and tube cross-fin heat exchanger, but it is not limited as such, and can be another type of heat exchanger.
[00060] In the present embodiment, the indoor unit 40 has an indoor fan 43 as an air blower, to bring indoor air inside the unit and supply air to the room as an air supply after the air has exchanged heat with the refrigerant in the interior heat exchanger 42. The interior fan 43 is a centrifugal fan, it is a fan with several blades, or another type of fan driven by a 43m motor composed of a DC fan motor, or similar.
[00061] The indoor unit 40 is equipped with several sensors. The liquid side of the interior heat exchanger 42 is provided with a temperature sensor on the liquid side 44 to detect the refrigerant temperature, and specifically the refrigerant temperature which corresponds to the Tsc refrigerant temperature of a subcooled state during operation. air heating temperature, or the evaporation temperature Te during the air cooling operation. Gas temperature sensors 45, 55, 65, to detect the refrigerant temperature are provided for the gas side of the indoor heat exchanger 42. The side of the indoor unit 40 that has an inlet port for the interior is provided with a indoor temperature sensor 46 to detect the indoor air temperature flowing into the unit, specifically the indoor temperature Tr. In the present embodiment, the liquid side temperature sensor 44, the gas temperature sensors 45, 55, 65 and the interior temperature sensor 46, are composed of thermistors. The indoor unit 40 has an indoor side controller 47 to control the actions of the components that make up the indoor unit 40. The indoor side controller 47 has a microcomputer, a memory 47a and / or the like provided to control the indoor unit 40, and the indoor side controller 47 is able to exchange control and similar signals with a remote controller (not shown) to operate the indoor unit 40 separately and also to exchange control and similar signals with the outdoor unit 20 via a line transmission 80a. (1-2) Outdoor unit
[00062] Outdoor unit 20 is installed outside a building or similar and is connected to indoor units 40, 50, 60 through liquid refrigerant communication tube 71 and gas refrigerant communication tube 72, constituting the refrigerant circuit 11, together with indoor units 40, 50, 60.
[00063] Next, the configuration of the outdoor unit 20 will be described. The outdoor unit 20 has a primary refrigerant circuit on the outer side 11d which forms part of the refrigerant circuit 11. The refrigerant circuit on the outer side 11d primarily has a compressor 21, a four-way switching valve 22 , an outer heat exchanger 23 as a heat exchanger on the heat source side, an outer expansion valve 38 as an expansion mechanism, and an accumulator 24, a liquid close valve 26 and a closing valve on the side gas 27.
[00064] Compressor 21 is a compressor capable of varying the operating capacity and, in the present mode, a positive displacement compressor driven by a 21m motor, in which the rotation speed is controlled by an inverter. In the present modality there is only one compressor 21, however the number of compressors is not limited as such, and two or more compressors can be connected in series according to the number of indoor units connected, and other factors.
[00065] The four-way switching valve 22 is a valve for switching the direction of refrigerant flow, and during air cooling operation the four-way switching valve is capable of connecting the discharge side of the compressor 21 and the gas side of the outer heat exchanger 23 and also connect the intake side of the compressor 21, specifically the accumulator 24 and the side of the gas refrigerant communication pipe 72, to make the outer heat exchanger 23 work as a condenser of the refrigerant compressed by compressor 21, and to make the interior heat exchangers 42, 52, 62 function as condenser refrigerant evaporators in the exterior heat exchanger 23 (air cooling operation status: see the full lines of the switching valve of four lanes 22 in figure 1). During the air heating operation the four-way switching valve is able to connect the discharge side of the compressor 21 and the side of the gas refrigerant communication pipe 72 and also connect the intake side of the compressor 21 and the side of the gas from the outer heat exchanger 23, to make the inner heat exchangers 42, 52, 62 act as condensers of the refrigerant compressed by the compressor 21, and to make the outer heat exchanger 23 act as an evaporator of the condensed refrigerant in the heat exchangers interiors 42, 52, 62 (air heating operation status: see the dashed lines of the four-way switching valve 22 in figure 1).
[00066] In the present embodiment, the outer heat exchanger 23 is a fin and cross-fin type heat exchanger, and is a device for using air as the heat source and conducting heat exchange with the refrigerant. The outer heat exchanger 23 is a heat exchanger which functions as a refrigerant condenser during air cooling operation, and which functions as a refrigerant evaporator during air heating operation. The gas side of the outer heat exchanger 23 is connected to the four-way switching valve 22 and the liquid side is connected to the outer expansion valve 38. In the present embodiment, the outer heat exchanger 23 is a fin-type heat exchanger and cross fin tubes, however it is not limited as such, and can be another type of heat exchanger.
[00067] In the present embodiment, the outer expansion valve 38 is an electric expansion valve placed downstream of the outer heat exchanger 23 (connected to the liquid side of the outer heat exchanger 23 in the present embodiment) in the direction of refrigerant flow in the refrigerant circuit 11 during the air cooling operation, to regulate the pressure, flow and / or other characteristics of the refrigerant flowing through the refrigerant circuit on the outside 11d.
[00068] In the present embodiment, the outdoor unit 20 has an outdoor fan 28 as an air blower, to bring outside air into the room and expel the air out of the room after the air has exchanged heat with the refrigerant in the room. outer heat exchanger 23. The outer fan 28 is a fan capable of varying the flow of air supplied to the outer heat exchanger 23 and, in the present mode, the outer fan is an impeller fan or similar, driven by a 28m compound motor DC fan motor or similar.
[00069] The liquid-side shut-off valve 26 and the gas-side shut-off valve 27 are valves provided for ports that connect with external equipment or piping, specifically the liquid refrigerant communication pipe 71 and the gas refrigerant communication pipe 72. The liquid-side shut-off valve 26 is placed downstream of the external expansion valve 38 and upstream of the liquid refrigerant communication pipe 71 in the direction of refrigerant flow in the refrigerant circuit 11 during the air cooling operation, and it is also able to block the passage of refrigerant. The gas-side shut-off valve 27 is connected to the four-way switching valve 22.
[00070] The outdoor unit 20 is equipped with several sensors. Specifically, the outdoor unit 20 is provided with an inlet pressure sensor 29 to detect the inlet pressure of the compressor 21, a discharge pressure sensor 30 for detecting the discharge pressure of the compressor 21, an inlet temperature sensor 31 to detect the intake temperature of the compressor 21 and a discharge temperature sensor 32 to detect the discharge temperature of the compressor 21. The side of the outdoor unit 20 which has an intake port for outside air is provided with an outdoor temperature sensor 36 to detect the temperature of the outside air flowing into the unit, specifically the outside temperature. In the present embodiment, the inlet temperature sensor 31, the discharge temperature sensor 32, and the outdoor temperature sensor 36, are composed of thermistors. The outdoor unit 20 has an outdoor controller 37 to control the actions of the components that make up the outdoor unit 20. The outdoor controller 37 has a microcomputer provided to control the outdoor unit 20, a memory 37a and / or an inverter circuit , or similar, to control the motor 21m, as shown in figure 2, and the controller on the outer side is able to exchange control and similar signals with the controllers on the inner side 47, 57, 67, of the indoor units 40, 50, 60, via transmission line 80a. Specifically, an operating controller 80 for controlling the operations of the entire air conditioning apparatus 10 is configured by the transmission line 80a connecting the inner side controllers 47, 57, 67 and the outer side controller 37.
[00071] The operation controller 80 is connected in order to be able to receive detection signals from the various sensors 29 to 32, 36, 39, 44 to 46, 54 to 56 and 64 to 66, and is connected in a way to be able to control the various devices and valves 21, 22, 28, 38, 41, 43, 51, 53, 61, 63, based on these and similar detection signals, as shown in figure 2. Various data are stored in the memories 37a, 47a, 57a, 67a, which constitute the operating controller 80. Figure 2 is a diagram of the control blocks of the apparatus for air conditioning 10. (1-2) Refrigerant communication tubes
[00072] Refrigerant communication tubes 71, 72 are refrigerant tubes constructed on site when the air conditioning apparatus 10 is installed in a building or other installation location, and refrigerant communication tubes of various lengths and / or diameters are used according to the installation location, the combination of outdoor and indoor units, and other installation conditions. Therefore, when an air conditioning apparatus is recently installed, for example, the air conditioning apparatus 10 must be filled with an amount of refrigerant suitable for the lengths and diameters of the refrigerant communication tubes 71, 72 and other conditions of the installation.
[00073] As described above, the refrigerant circuits on the inner side 11a, 11b, 11c, the refrigerant circuit on the outer side 11d, and the refrigerant communication tubes 71, 72, are connected to constitute the refrigerant circuit 11 of the apparatus for air conditioning 10. In the air conditioning apparatus 10 of the present modality, the operating controller 80 configured from the controllers on the inner side 47, 57, 67, and the controller on the outer side 37, perform the switching operation between the air cooling operation and the air heating operation via the four-way switching valve 22, and also control the various devices of the outdoor unit 20 and indoor units 40, 50, 60, according to the loads of operation of indoor units 40, 50, 60. (2) Appliance action for air conditioning
[00074] Next, the action of the air conditioning apparatus 10 of the present modality will be described.
[00075] In the air conditioning unit 10, during the air cooling operation and the air heating operation described below, the indoor units 40, 50, 60 are subjected to optimization control of the indoor temperature to bring the indoor temperature Tr close to a set temperature Ts that a user has set via a remote controller, or other type of input. In this interior temperature optimization control, the opening degree of the interior expansion valves 41, 51, 61 is adjusted so that the interior temperature Tr converges with the set temperature Ts. The phrase "the opening degrees of the interior expansion valves 41, 51, 61 are regulated" used here, means that the degrees of overheating of the outputs of the interior heat exchangers 42, 52, 62 are controlled in the case of the cooling operation of air, and that the degrees of cooling of the outputs of the interior heat exchangers 42, 52, 62 are controlled in the case of the air heating operation. (2-1) Air cooling operation
[00076] Air cooling operation using figure 1 will first be described.
[00077] During the air cooling operation, the four-way switching valve 22 is in a state shown by the solid lines in figure 1, that is, the discharge side of the compressor 21 is connected to the gas side of the air exchanger exterior heat 23, and the intake side of the compressor 21 is connected to the gas sides of the interior heat exchangers 42, 52, 62, via the gas side shut-off valve 27 and the gas refrigerant communication pipe 72. A outer expansion valve 38 is fully open. The liquid-side shut-off valve 26 and the gas-side shut-off valve 27 are open. The opening degrees of the interior expansion valves 41, 51, 61 are adjusted so that the degrees of superheat SH of the refrigerant at the outlets of the interior heat exchangers 42, 52, 62, that is, the gas sides of the heat exchangers interiors 42, 52, 62 stabilizes at a target degree of SHt overheating. The target degree of superheat SHt is set to a temperature value that is optimized so that the indoor temperature TR converges over the set temperature Ts within a predetermined degree of superheat range. In the present mode, the degrees of superheat SH of the refrigerant at the outputs of the interior heat exchangers 42, 52, 62 are detected by subtracting the refrigerant temperature values (which correspond to the evaporation temperature Te) detected by the temperature sensors on the liquid side 44, 54, 64, of the refrigerant temperature values detected by the gas side temperature sensors 45, 55, 65. The degrees of SH superheat of the refrigerant at the outputs of the interior heat exchangers 42, 52, 62 are not limited to being detected by the method described above, and can be detected by converting the inlet pressure of the compressor 21 detected by the inlet pressure sensor 29 to a saturation temperature value that corresponds to the evaporation temperature Te, and subtracting this saturation temperature value from refrigerant temperature values detected by the gas side temperature sensors 45, 55, 65. Although not used In this mode, temperature sensors can be provided to detect the temperatures of refrigerant flowing through each of the interior heat exchangers 42, 52, 62, and the degrees of overheating SH of the refrigerant at the outputs of each of the heat exchangers. indoor heat 42, 52, 62 can be detected by subtracting the refrigerant temperature values that correspond to the evaporation temperature Te detected by these temperature sensors from the refrigerant temperature values detected by the gas side temperature sensors 45, 55, 65.
[00078] When compressor 21, outdoor fan 28 and indoor fans 43, 53, 63 are operated with refrigerant circuit 11 in this state, low pressure gas refrigerant is brought to compressor 21 and compressed to high gas refrigerant pressure. The high-pressure gas refrigerant is then sent through the four-way switching valve 22 to the external heat exchanger 23, subjected to heat exchange with the outside air supplied by the external fan 28, and condensed to high-pressure liquid refrigerant. The high-pressure liquid refrigerant is sent through the liquid-side shut-off valve 26 and the liquid refrigerant communication pipe 71 to indoor units 40, 50, 60.
[00079] The high-pressure liquid refrigerant sent to the indoor units 40, 50, 60 is depressurized approximately to the inlet pressure of the compressor 21 by means of the interior expansion valves 41, 51, 61, becoming gas two-phase refrigerant -liquid low pressure, which is sent to the interior heat exchangers 42, 52, 62, subjected to heat exchange with indoor air in the interior heat exchangers 42, 52, 62, and evaporated to low pressure gas refrigerant.
[00080] This low pressure gas refrigerant is sent through the gas refrigerant communication tube 72 to the outdoor unit 20 and the refrigerant flows through the gas-side shut-off valve 27 and the four-way switching valve 22 to the accumulator. 24. The low-pressure gas refrigerant that has drained into the accumulator 24 is brought back to the compressor 21. Thus, in the air conditioning unit 10, it is possible to carry out at least the air cooling operation, in which the outside heat exchanger 23 is made to function as a condenser of compressed refrigerant in the compressor 21, and the interior heat exchangers 42, 52, 62, are made to function as evaporators of refrigerant that have been condensed in the external heat exchanger 23 and then sent through the tube liquid refrigerant communication system 71 and the internal expansion valves 41, 51, 61. Since the air conditioning apparatus 10 does not have a mechanism for regulating refrigerant pressure on the gas sides of the interior heat exchangers 42, 52, 62, the evaporation pressures Te on all interior heat exchangers 42, 52, 62 are the same pressure. (2-2) Air heating operation
[00081] Next, the air heating operation will be described.
[00082] During the air heating operation the four-way switching valve 22 is in the state shown by the dashed lines in figure 1 (air heating operation state), that is, the discharge side of the compressor 21 is connected to the gas sides of the interior heat exchangers 42, 52, 62, through the gas-side shut-off valve 27 and the gas refrigerant communication pipe 72 and the intake side of the compressor 21 are connected to the gas side of the heat exchanger external heat 23. The degree of opening of the external expansion valve 38 is regulated to reduce the pressure to a pressure at which the refrigerant flowing into the external heat exchanger 23 can be evaporated in the external heat exchanger 23 (ie , an evaporation pressure Pe). The liquid-side shut-off valve 26 and the gas-side shut-off valve 27 are open. The opening degrees of the interior expansion valves 41, 51, 61 are regulated so that the degrees of subcooling SC of the refrigerant at the outlets of the interior heat exchangers 42, 52, 62 stabilize at a target degree of subcooling SCt. The target degree of subcooling SCt is adjusted to the temperature value used to cause the indoor temperature Tr to converge over the setting temperature Ts within the degree of subcooling range specified according to the current state of operation. In the present mode, the degrees of subcooling SC of the refrigerant at the outputs of the interior heat exchangers 42, 52, 62 are detected by converting the discharge pressure Pd of the compressor 21 detected by the discharge pressure sensor 30 to a temperature value of saturation corresponding to the condensing temperature Tc, and subtracting the refrigerant temperatures Tsc detected by the liquid side temperature sensors 44, 54, 64 from this refrigerant saturation temperature value. Although not used in the present modality, temperature sensors can be provided to detect the refrigerant temperature that flows through each of the interior heat exchangers 42, 52, 62 and the degrees of subcooling SC of the refrigerant at the outputs of the heat exchangers. indoor heat 42, 52, 62 can be detected by subtracting the refrigerant temperature values that correspond to the condensing temperature Tc detected by these temperature sensors, from the refrigerant temperatures Tsc detected by the liquid side temperature sensors 44, 54, 64.
[00083] When compressor 21, outdoor fan 28 and indoor fans 43, 53, 63 are operated with refrigerant circuit 11 in this state, low pressure gas refrigerant is brought into compressor 21 and compressed to gas refrigerant high pressure switch, which is sent via the four-way switching valve 22, the gas-side shut-off valve 27 and the gas refrigerant communication pipe 72, to indoor units 40, 50, 60.
[00084] The high pressure gas refrigerant sent to indoor units 40, 50, 60 is subjected to heat exchange with the indoor air in the indoor heat exchangers 42, 52, 62 and condensed to high pressure liquid refrigerant and, when this refrigerant then passes through the interior expansion valves 41, 51, 61, the refrigerant is depressurized according to the degrees of valve opening in the interior expansion valves 41, 51, 61.
[00085] Having passed through the internal expansion valves 41, 51, 61, the refrigerant is sent through the liquid refrigerant communication tube 71 to the outdoor unit 20 passed through the liquid side shut-off valve 26 and the expansion valve and exterior 38, and still depressurized, after which the refrigerant flows into the exterior heat exchanger 23. The two-stage low pressure gas-liquid refrigerant that flows into the exterior heat exchanger 23 is subjected to exchange of heat with outside air supplied by the external fan 28 and evaporated to low pressure gas refrigerant that flows through the four-way switching valve 22 into the accumulator 24. The low pressure gas refrigerant that flows into the accumulator 24 is again brought into compressor 21. (2-3) Expansion valve correlation control
[00086] In the air conditioning apparatus 10, during air heating operation, the operation controller 80 performs expansion valve correlation control to regulate the degree of opening of the outer expansion valve 38 based on the representative degree of opening of the internal expansion valves 41, 51, 61. The operating controller 80 employs as the representative opening degree of the internal expansion valves 41, 51, 61, an opening degree of the internal expansion valve which is the maximum opening degree between the opening degrees of the interior expansion valves 41, 51, 61, hereinafter referred to as the opening degree of the expansion valve employed. In the air conditioning apparatus 10 of the present embodiment, the operating controller 80 regulates the degree of opening of the external expansion valve 38 so that the amount of depressurization by means of the internal expansion valves at the maximum degree of opening between the degrees of opening of the interior expansion valves 41, 51, 61, is sufficient for the liquid phase to be maintained even after depressurization, for example, 0.2 MPa (a predetermined target value of the valve opening pulse setting that corresponds to a depressurizing amount of 0.2 MPa). At this time, the opening degrees of the interior expansion valves 41, 51, 61 are adjusted so that the degrees of subcooling SC of the refrigerant at the outlets of the interior heat exchangers 42, 52, 62, stabilizes at the target degree of sub- SCt cooling as described above. Specifically, the opening degrees of all expansion valves 38, 41, 51, 61 are regulated so that the amount of depressurization in each of the interior expansion valves 41, 51, 61, stabilizes at 0.2 MPa and the degrees of subcooling SC of the refrigerant at the outputs of the interior heat exchangers 42, 52, 62 stabilize at the target degree of subcooling SCt.
[00087] Next, the cooling cycle in the air conditioning unit 10 will be described. Figure 3 uses a p-h graph (a Mollier diagram) to show the refrigeration cycle in refrigerant circuit 11 of the air conditioning apparatus 10 of the present modality. Points A, B, C, D and E in figure 3 represent states of the refrigerant that correspond to the respective points in figure 1 during an air heating operation.
[00088] In this refrigerant circuit 11, the refrigerant is compressed by the compressor 21 for a high temperature and high pressure Ph (A ^ B). The refrigerant gas compressed by the compressor 21 for a high temperature and high pressure Ph is made to release heat by the external heat exchanger 23 which functions as a condenser becoming a low temperature, high pressure liquid refrigerant Ph (B ^ C). Having released heat in the external heat exchanger 23, the refrigerant is depressurized by the internal expansion valves 41, 51, 61, from a high pressure Ph to an intermediate pressure Pm (C ^ D). The amount of depressurization by means of the internal expansion valves 41, 51, 61, at this moment is adjusted to 0.2 MPa and the refrigerant at point D is in a liquid phase as shown in figure 3. Specifically, the communication pipe of liquid refrigerant 71 from the internal expansion valves 41, 51, 61, until the external expansion valve 38 can be filled with liquid refrigerant. The depressurized refrigerant for intermediate pressure Pm flows into the interior of the outdoor unit 20 where it is depressurized by means of the external expansion valve 38 from intermediate pressure Pm to a low pressure Pl, becoming a two-phase gas-liquid refrigerant ( D ^ E). The heat from the gas-liquid two-phase refrigerant is absorbed in the outer heat exchanger 23 that functions as an evaporator, and the refrigerant evaporates and returns to the compressor 21 (E ^ A). (3) Features (3-1)
[00089] In the air conditioning apparatus 10 of the present embodiment, the representative opening degree of the interior expansion valves 41, 51, 61 is controlled so that the valve opening pulse, which is a predetermined opening degree, reaches a value predetermined target, whereby the degree of opening of the external expansion valve 38 is regulated so that the amount of depressurization by means of the internal expansion valves 41, 51, 61 is sufficient for the liquid phase to be maintained even after depressurization , for example, 0.2 MPa.
[00090] Therefore, the amount of depressurization by means of the external expansion valve 38 can be prevented from decreasing severely and the refrigerant inside the liquid refrigerant communication tube 71 can be prevented from going to a two-phase gas-state. liquid. Therefore, an excess of refrigerant in the refrigerant circuit 11 can be prevented, and wet compression can be prevented from occurring in the compressor 21.
[00091] Balance between the amount of depressurization through the inner expansion valves 41, 51, 61 and the amount of depressurization through the outer expansion valve 38 is achieved by regulating the degree of opening of the outer expansion valve 38, so that the representative degree of opening in the interior expansion valves 41, 51, 61, stabilizes, and the intermediate pressure Pm can therefore be regulated without adding a pressure sensor, or similar, to detect the intermediate pressure Pm between the pressure valves internal expansion valves 41, 51, 61 and the external expansion valve 38, for example. (3-2)
[00092] In the air conditioning apparatus 10 of the present embodiment there are a plurality of indoor units 40, 50, 60. The operating controller 80 of the air conditioning apparatus 10 employs the maximum opening degree in the interior expansion valves 41, 51, 61, as the representative degree of openness. For example, when the indoor units 40, 50, 60 are in the off state, the degrees of opening of the interior expansion valves 41, 51, 61 are set to an extremely small degree of opening, so the opening pulse of valve is the minimum default value. Even in such cases, in the air conditioning apparatus 10 the amount of depressurization by means of the external expansion valve 38 is regulated based on the amount of depressurization by means of the internal expansion valves 41, 51, 61.
[00093] There may be cases in which the indoor unit 40 has a small required load and goes to the off state, the degree of opening of the indoor expansion valve 41 is extremely small, and the required load for the indoor unit 50 is large, such as showing 100% of the design capacity, for example. Even in such cases, the controllers on the inner side 47, 57, 67, employ the maximum degree of opening on the interior expansion valves 41, 51, 61, as the representative degree of opening, and regulate the degree of opening of the expansion valve exterior 38 based on the representative degree of openness. Therefore, between the quantities of depressurization by means of the internal expansion valves 41, 51, 61, and by means of the external expansion valve 38, a quantity of depressurization of 0.2 MPa can be ensured as the amount of depressurization by means of the interior expansion valves 41, 51, 61. Specifically, the amount of depressurization by means of the interior expansion valves 41, 51, 61, can be prevented from being set to an extremely small amount of depressurization. The degree of openness of the indoor expansion valve 41 of the indoor unit 40 which requires a small load, and the degree of openness of the indoor expansion valve 51 of the indoor unit 50 which requires a large load can each be adjusted for a ratio specific for the respective required load. Specifically, the amount of refrigerant that flows to a unit of use that requires a small charge and the amount of refrigerant that flows to a unit of use that requires a large load can be adjusted to a ratio suitable for the required charges. Consequently, an excessive amount of refrigerant can be prevented from flowing to a unit of use that requires a small charge, and energy can be conserved. (3-3)
[00094] In the air conditioning apparatus 10 of the present embodiment, the outdoor unit 20 has an accumulator 24 on the intake side of the compressor 21.
[00095] Therefore, any excess refrigerant that occurs in refrigerant circuit 11, depending on operating conditions, can be accumulated in accumulator 24. Therefore, liquid compression can be prevented from occurring in compressor 21. Modifications (4-1) Modification 1
[00096] In the air conditioning apparatus 10 of the modality described above, the maximum opening degree between the opening degrees of the interior expansion valves 41, 51, 61, is used as the representative opening degree, however to use a value more precise as the representative opening degree, another possible option is that the opening degrees of the interior expansion valves 41, 51, 61 are corrected based on the specifications of the indoor units and the maximum opening degree between the opening degrees after of this correction (the corrected opening degrees) is used as the representative opening degree. The term "indoor unit specifications" used here refers to the relationship between a specific flow based on the refrigerant flow required to reach the rated capacity of the indoor units 40, 50, 60, under predetermined conditions and the opening of the expansion valve indoor 41 of indoor unit 40. Specifically, when the specific flow rate of indoor unit 40 is 1, indoor unit 40 can be observed to have 100% of its rated capacity and when the specific flow rate of indoor unit is 0.6 the indoor unit 40 can be observed to have 60% of its rated capacity.
[00097] More specifically, the degree of opening of the correction (here below the degree of opening corrected) is a value obtained by dividing the degree of opening of the internal expansion valve 41 detected at the moment, by the degree of opening of the internal expansion valve 41 in which the specific flow is 1 and the amount of depressurization is 0.2 MPa. For the purpose of convenience in the description, only indoor unit 40 is described here, but the same description applies to indoor units 50, 60.
[00098] In this case, specification data of the indoor units 40, 50, 60 are stored in memories 47a, 57a, 67a, of the controllers on the inside side and the corrections of the opening degrees of the interior expansion valves 41, 51, 61 are performed by the controllers on the inner side 47, 57, 67. Corrections to the degrees of openness of the interior expansion valves 41, 51, 61 are not limited as such, however, and can be performed by the controller on the outer side 37.
[00099] Thus, since the opening degrees of the interior expansion valves 41, 51, 61 are corrected based on the specifications of the indoor units 40, 50, 60, the corrected opening degrees and the actual depressurization quantities of the valves of expansion on the use side can be made to approach a proportional relationship. Therefore, even if the units of use have different specifications, the degree of opening of the expansion valve on the heat source side can be regulated based on a valve close to the actual depressurization quantities of the expansion valves on the use side, and the The amount of depressurization through the heat exchanger on the heat source side can be regulated more precisely. (4-2) Modification 2
[000100] In the air conditioning apparatus 10 of the mode described above, the maximum opening degree between the opening degrees of the interior expansion valves 41, 51, 61, is used as the representative opening degree, however to use a value more precise as the representative opening degree, another possible option is that the opening degrees of the interior expansion valves 41, 51, 61 are corrected based on the installation conditions of the indoor units, and the maximum opening degree between the degrees of opening after this correction (the corrected opening degrees) is used as the representative opening degree. The term "indoor unit installation conditions" used herein refers to the tube lengths and tube diameters of the refrigerant communication tubes 71, 72, from the outdoor unit 20 to the indoor units 40, 50, 60.
[000101] More specifically, the degree of opening of the correction (here below the degree of opening corrected) is a value obtained by dividing the degree of opening of the inner expansion valve 41 detected at the moment, by the degree of opening of the expansion valve interior 41 in which the specific flow is 1 and the amount of depressurization is 0.2 MPa, taking into account the pressure loss in the refrigerant communication pipes from the outdoor unit 20 to the indoor unit 40. For example, there could be a case in which the specific flow is 1, the pressure loss in the refrigerant communication tubes 71, 72 from the outdoor unit 20 to the indoor unit 40 is 0.10 MPa and the pressure loss in the refrigerant communication tubes 71, 72 from the outdoor unit 20 to the indoor unit 60 is 0.2 MPa. In the indoor unit 40 since the pressure loss in the refrigerant communication pipes 71, 72 is 0.10 MPa, the degree of opening corrected to an opening degree that corresponds to 0.1 MPa which is 0.1 MPa subtracted from 0.2 MPa for the amount of depressurization in the indoor unit 40 to be 0.2 MPa including the refrigerant communication tubes and 71, 72, from outdoor unit 20 to indoor unit 40. In indoor unit 60, once that the pressure loss in the refrigerant communication tubes 71, 72 is 0.02 MPa the degree of opening is corrected to a degree of opening that corresponds to 0.18 MPa which is 0.02 MPa minus 0.2 MPa for the amount of depressurization in the indoor unit 60 to be 0.2 MPa including the refrigerant communication pipes 71, 72, from the outdoor unit 20 to the indoor unit 60. Correcting the opening degrees of each of the internal expansion valves of this In this way, the opening degrees of the interior expansion valves can be adjusted so that the amount of depressurization will actually be 0.2 MPa.
[000102] For convenience of description, only indoor unit 40 is described here, but the same description applies to indoor units 50, 60. Refrigerant communication pipes from outdoor unit 20 to indoor unit 40 are taken into account here, but this is not the only possible option, and another option is to take into account the parts of the refrigerant communication tubes 71, 72 that start at branch points F, G (see figure 1) and end at the units interior (40, 50, 60), these branch points being where the refrigerant communication pipes 71, 72, branch to the indoor unit 60, which is the indoor unit closest to the outdoor unit 20. The correction of the opening degrees of internal expansion valves 41, 51, 61 in modification 2 can be used in conjunction with correction of modification 1.
[000103] This, since the opening degrees of the interior expansion valves 41, 51, 61, are corrected based on the installation conditions of the indoor units 40, 50, 60, the corrected opening degree and the actual quantities of depressurization of the expansion valves on the side of use can be made to approach a proportional ratio. Therefore, even if the units of use have different specifications, the degree of opening of the expansion valve on the heat source side can be regulated based on a value close to the actual depressurization quantities of the expansion valves on the use side, and the The amount of depressurization through the heat exchanger on the heat source side can be regulated more precisely. (4-3) Modification 3
[000104] In the air conditioning apparatus 10 of the mode described above, the interior expansion valves 41, 51, 61, are not fixed in the completely closed state, but are regulated to extremely small degrees of opening, in order to ensure a flow of refrigerant to prevent liquid refrigerant from accumulating in the interior heat exchangers, however the opening degrees of the interior expansion valves 41, 51, 61 are not limited to be set to extremely small opening degrees. For example, refrigerant flow can be ensured by performing a control to close and open the interior expansion valves 41, 51, 61 intermittently and completely repeatedly. (4-4) Modification 4
[000105] In the air conditioning apparatus 10 of the mode described above, the opening degrees of the interior expansion valves 41, 51, 61 are adjusted so that the valve opening pulses reach the predetermined target value which is a value fixed to bring the quantities of depressurization through the interior expansion valves 41, 51, 61, to 0.2 MPa, however the opening degrees of the interior expansion valves 41, 51, 61, are not limited to this option, and can be corrected based on the outside air temperature. (4-5) Modification 5
[000106] In the air conditioning apparatus 10 of the modality described above, the maximum opening degree between the opening degrees of the interior expansion valves 41,51, 61, is used as the representative opening degree, however the opening degree representative is not limited to this option, and the average opening degree of the interior expansion valves 41, 51, 61 can be used as the representative opening degree. (4-6) Modification 6.
[000107] In the air conditioning apparatus 10 of the modality described above, although not implicitly described, the target value of the representative degree of openness of the interior expansion valves 41, 51, 61, which is used as a base when the degree of opening of the outer expansion valve 38 is regulated, it can be floated by means of the operating controller 80 according to the status of the refrigerant in the refrigerant circuit 11, such as tending to be an excess or an insufficiency (the state of the amount of refrigerant in the system). Specifically, when the status of the amount of refrigerant in the system in the refrigerant circuit 11 is a trend of excess, the answer is to increase the target value of the representative degree of openness of the interior expansion valves 41, 51, 61, based on the control degree of opening of the external expansion valve 38 and, when the state of the amount of refrigerant in the system in the refrigerant circuit 11 is a tendency of an insufficiency, the answer is to reduce the target value of the representative degree of opening of the internal expansion valves 41, 51, 61, based on the control of the degree of opening of the external expansion valve 38.
[000108] Such control makes it possible to place the refrigerant in a liquid refrigerant communication tube 71 in a high density liquid state when the state of the amount of refrigerant in the refrigerant circuit is a tendency to be an excess. Therefore, the amount of refrigerant retained in the liquid refrigerant communication tube 71 can be increased as much as possible, and operation is possible even when there is an excess of refrigerant.
[000109] When the status of the amount of refrigerant in the refrigerant circuit 11 is a tendency to be insufficient, the refrigerant in the liquid refrigerant communication tube 71 can be placed in a two-phase low-density gas-liquid state. Therefore, the amount of 'refrigerant retained in the liquid refrigerant communication tube 71 can be reduced, the reduced amount can be retained in the heat exchangers on the side of use, and operation is possible even when there is insufficient refrigerant. LIST OF REFERENCE SIGNS 10. Air conditioning device 20. Outdoor unit (heat source unit) 21. Compressor (compression mechanism) 23. Outdoor heat exchanger (heat exchanger on the heat source side) 24. Accumulator 38 External expansion valve (heat source side expansion valve) 41. 51, 61. Interior expansion valves (use side expansion valves) 42. 52, 62. Indoor units (use units) 80. Controller of operation (controller) LIST OF QUOTES Patent Literature Patent Literature 1- Japanese Patent Application open for public inspection number 2002-39,642

权利要求:
Claims (2)
[0001]
1. Air conditioning apparatus (10), comprising: a heat source unit (20) that has a compression mechanism (21), a heat exchanger on the heat source side (23) that functions at least as a evaporator, and an expansion valve on the heat source side (38); a plurality of use units (40, 50, 60) that have heat exchangers on the use side (42, 52, 62) that function at least as capacitors, and expansion valves on the use side (41, 51, 61 ) and a controller (80) for regulating the degree of opening of the expansion valve on the heat source side (38) based on the degrees of opening of the expansion valves on the use side (41, 51, 61); wherein the heat source unit (20) also has an accumulator (24) on the inlet side of the compression mechanism; the controller (80) regulates the degree of opening of the expansion valves on the side of use (41, 51, 61) during an air heating operation, so that the degree of subcooling at the heat exchanger outlets on the side of use (42, 52, 62) reaches a degree of subcooling target value; characterized by the fact that the controller (80) defines the degree of the subcooling target value for each of the utilization units (40, 50, 60) according to the required load of each utilization unit (40, 50, 60); the controller (80) regulates the degree of opening of the expansion valve on the heat source side (38) based on a maximum degree of opening or an average degree of opening between the degrees of opening of the expansion valves on the side of use (41, 51, 61) of the use units (40, 50, 60); the controller (80) regulates the degree of opening of the expansion valve on the heat source side (38), so that the amount of depressurization by the expansion valves on the use side (41, 51, 61) at the maximum opening degree or at an average degree of opening between the degrees of opening of the internal expansion valves (41, 51, 61), the liquid phase is sufficient to be maintained after depressurization.
[0002]
2. Air conditioning apparatus (10), according to claim 1, characterized by the fact that the controller (80) causes the target value of the opening degrees of the expansion valves on the use side (41, 51 , 61) fluctuates according to a system refrigerant quantity state estimated from the operational state, the target value being a reference to regulate the degree of opening of the expansion valve on the heat source side (38).

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

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2019-11-26| B06U| Preliminary requirement: requests with searches performed by other patent offices: procedure suspended [chapter 6.21 patent gazette]|

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2020-11-10| B09A| Decision: intention to grant [chapter 9.1 patent gazette]|

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2021-01-05| 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 21/07/2011, 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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JP2010173612A|JP4968373B2|2010-08-02|2010-08-02|Air conditioner|

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JP2010-173612|2010-08-02|

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PCT/JP2011/066533|WO2012017829A1|2010-08-02|2011-07-21|Air conditioning device|

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