JP2018035979A - Method of inspecting heat pump system, and heat pump system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of inspecting a heat pump system that can correctly recognize a refrigerant filling amount for a refrigerant circulation path.SOLUTION: A method of inspecting a heat pump system has: a status value detecting process of detecting, after letting a refrigerant sent out from compression means 5 flow to a first heat exchanger 8, a second expansion valve V2 and a third heat exchanger 10 in order in a cutoff state in which the refrigerant is not circulated via the first expansion valve V1 and a second heat exchanger 14, a status value of a refrigerant being circulated while performing an inspecting operation by switching the circulation state of the refrigerant so that the refrigerant returns to the compression means 5; and a refrigerant filling amount determination process of determining, based upon the status value detected in the status value detecting process, whether the filling amount of the refrigerant present in a refrigerant circulation path 3 is proper.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a heat pump system inspection method for cooling or heating a heat exchange target fluid using a refrigerant flowing in a refrigerant circuit, and a heat pump system.

  In a heat pump system that cools or heats the air-conditioning target space by performing heat exchange between the refrigerant flowing through the refrigerant circulation path and the heat-exchange target fluid such as air in the air-conditioning target space, Are provided with a heat exchanger functioning as a compressor, a condenser, and an evaporator. In such a heat pump system, a failure that the refrigerant leaks from the middle of the refrigerant circuit may occur. In order to detect such refrigerant leakage, conventionally, an inspection method for diagnosing the presence or absence of refrigerant leakage from the refrigerant circuit has been proposed.

  For example, Patent Document 1 (Japanese Patent No. 5245575) includes a compressor, a heat source side heat exchanger (condenser), an expansion mechanism, and a use side heat exchanger (evaporator), and performs a cooling operation. A possible heat pump system is described. Then, while performing the cooling operation, the refrigerant amount determination operation mode for detecting the degree of refrigerant subcooling at the outlet of the heat source side heat exchanger (condenser) and determining the suitability of the refrigerant amount charged in the refrigerant circuit. Is described.

  Thus, in the invention described in Patent Document 1, for example, the state of the refrigerant is detected while circulating the refrigerant with respect to the compressor, the condenser, the evaporator, and the like in the same route as when actually operating, An attempt is made to determine the state of refrigerant leakage based on the detected value.

Japanese Patent No. 5245575

However, in a normal heat pump system in which the indoor heat exchanger and the outdoor heat exchanger function as either a condenser or an evaporator, the indoor heat exchanger is provided at a location away from the outdoor heat exchanger, The length of the refrigerant circuit leading to the exchanger varies. Moreover, the temperature of the heat exchange target fluid that exchanges heat with the refrigerant in the indoor heat exchanger varies, and the number of indoor heat exchangers installed is also different. For this reason, even if the state of the refrigerant is detected while flowing the refrigerant through the same path as in the actual operation, the detected value is the amount of refrigerant charged at that point in the refrigerant circuit (that is, refrigerant leakage occurs) It depends on the length of the refrigerant circuit, the state of heat exchange in the indoor heat exchanger and the outdoor heat exchanger, the number of indoor heat exchangers installed, etc. Change.
As described above, in the conventional inspection method, since the state of the refrigerant is detected while circulating the refrigerant through the same path as in the actual operation, it is not possible to correctly recognize whether the refrigerant charging amount in the refrigerant circulation path is appropriate. there is a possibility.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a heat pump system inspection method and a heat pump system that can correctly recognize the suitability of the refrigerant charge amount in the refrigerant circuit.

In order to achieve the above object, the characteristic configuration of the inspection method of the heat pump system according to the present invention includes a refrigerant circulation path through which a refrigerant circulates, an engine, and compression that compresses the refrigerant that is driven by the engine and flows through the refrigerant circulation path. Means, a first heat exchanger capable of performing heat exchange between the refrigerant flowing through the refrigerant circulation path and the outside air, and heat between the refrigerant flowing through the refrigerant circulation path and the heat exchange target fluid A second heat exchanger that can be exchanged, a first expansion valve that expands the refrigerant flowing into the second heat exchanger, a refrigerant that flows through the refrigerant circuit, and exhaust heat that is released from the engine. A third heat exchanger capable of performing heat exchange between the first heat exchanger and a second expansion valve for expanding the refrigerant flowing into the third heat exchanger,
The refrigerant sent from the compression means is not circulated through the second expansion valve and the third heat exchanger, and the refrigerant sent from the compression means is the first heat exchanger, the first expansion valve, and the second heat exchange. In the second heat exchanger acting as an evaporator, the heat exchange is performed by the refrigerant flowing through the refrigerant circulation path by switching the circulation state of the refrigerant so as to return to the compression means after sequentially flowing through the evaporator. An inspection method for a heat pump system capable of performing a cooling operation for cooling a target fluid,
In the shut-off state in which the refrigerant is not circulated via the first expansion valve and the second heat exchanger, the refrigerant sent from the compression means is used as the first heat exchanger, the second expansion valve, and the third heat. A state value detection step of detecting the state value of the circulating refrigerant while performing the inspection operation by switching the circulation state of the refrigerant so as to be returned to the compression means after sequentially flowing through the exchanger;
A refrigerant charge amount determination step of determining whether or not the refrigerant charge amount existing in the refrigerant circulation path is appropriate based on the state value detected in the state value detection step.

According to the above characteristic configuration, when the state value detection step is performed while performing the inspection operation, the refrigerant sent from the compression means passes through the first heat exchanger, the second expansion valve, and the third heat exchanger in order. After flowing, the refrigerant returns to the compression means, and the refrigerant is not circulated through the first expansion valve and the second heat exchanger used during the cooling operation. At this time, the refrigerant does not circulate in the second heat exchanger acting as an evaporator during cooling operation, but the heat between the refrigerant flowing through the refrigerant circulation path and the exhaust heat released from the engine in the third heat exchanger. By performing the exchange, the third heat exchanger acts as an evaporator in the heat pump cycle. Thus, when the state value detection step is performed, the refrigerant circulates without passing through the second heat exchanger in which heat exchange with the heat exchange target fluid is performed, and thus passes through the second heat exchanger. The length of the refrigerant circulation path required to flow the refrigerant, the heat exchange status in the second heat exchanger that changes according to the temperature and amount of the heat exchange target fluid, the number of installed second heat exchangers, etc. The state value of the circulating refrigerant can be accurately detected in a state where many of the factors that can change the state value of the refrigerant are eliminated.
In addition, in the state value detection process, since the state value of the circulating refrigerant is detected, it is determined that the steady state is obtained as compared with the case where the state value of the refrigerant is detected while the circulation is stopped. It can be expected that a more accurate refrigerant state value is detected.

  Furthermore, even if the second heat exchanger is an indoor heat exchanger that exchanges heat with air in a room or the like, heat exchange (for example, cooling of the air in the room) is not performed in the indoor heat exchanger. Therefore, it is possible to prevent the cold air from being unexpectedly supplied to the room when the state value detection step is performed.

  In the refrigerant charge amount determination step, it is possible to determine whether the refrigerant charge amount existing in the refrigerant circulation path is appropriate based on the comparison result between the accurate state value detected in the state value detection step and the predetermined reference value. Accordingly, it is possible to provide an inspection method for a heat pump system that can correctly recognize the refrigerant charging amount in the refrigerant circuit.

  Another characteristic configuration of the inspection method of the heat pump system according to the present invention is that when the state value is detected in the state value detection step, the inspection operation is performed to perform circulating refrigerant in the third heat exchanger. The evaporating pressure lies in that the cooling operation is performed to lower the evaporating pressure of the circulating refrigerant in the second heat exchanger.

  According to the above characteristic configuration, the evaporating pressure in the circulating refrigerant evaporator (third heat exchanger) by performing the inspection operation is equal to the circulating refrigerant evaporator (second heat) by performing the cooling operation. It will be lower than the evaporation pressure at the exchanger. When the evaporation pressure is reduced in the heat pump cycle, when the condensation pressure and the degree of superheat of the refrigerant at the compressor inlet are the same, the amount of heat necessary for evaporating the refrigerant with respect to the power for compressing the refrigerant becomes small. This means that the heat pump cycle can be operated even when the engine exhaust heat ratio is small.

  Still another characteristic configuration of the inspection method for the heat pump system according to the present invention is that the state value is a degree of supercooling of the refrigerant.

  According to the above characteristic configuration, when operating the heat pump cycle, the condensation pressure, the evaporation pressure, and the degree of superheat are likely to be controlled, but the degree of supercooling is an item that appears as a result of the operation control, and the refrigerant is charged. Strong correlation with quantity. Therefore, it is possible to appropriately determine whether the refrigerant charging amount is appropriate based on the degree of supercooling of the refrigerant.

Still another characteristic configuration of the inspection method for the heat pump system according to the present invention is that the heat pump system includes a cooling water circulation path through which cooling water for recovering exhaust heat released from the engine circulates, and the third heat exchanger. Then, heat exchange between the refrigerant flowing through the refrigerant circulation path and the cooling water flowing through the cooling water circulation path can be performed,
When the state value is detected in the state value detection step, the flow rate per unit time of the cooling water supplied to the third heat exchanger through the cooling water circulation path is set to a set cooling water amount or less.

  According to the above characteristic configuration, when the flow rate per unit time of the cooling water supplied to the third heat exchanger is reduced below the set cooling water amount, the third heat exchanger as the refrigerant evaporator The heat exchange performance with respect to the refrigerant decreases. For this reason, when the condensation pressure and the superheat degree of the refrigerant at the compressor inlet are approximately the same, the evaporation pressure decreases, and the heat pump cycle can be operated even when the engine exhaust heat ratio is small.

Still another characteristic configuration of the inspection method of the heat pump system according to the present invention is that the cooling water circulation path includes a first bypass path through which the cooling water can circulate bypassing the third heat exchanger, and the first bypass path. A cooling water distributor capable of adjusting the distribution state of the cooling water of
When the state value is detected in the state value detection step, the flow rate per unit time of the cooling water supplied to the third heat exchanger through the cooling water circulation path is set using the cooling water distributor. The point is to make it less than the amount of water.

  According to the above characteristic configuration, the flow rate of the cooling water supplied to the third heat exchanger per unit time can be reduced below the set cooling water amount by the operation of the cooling water distributor.

Still another characteristic configuration of the inspection method of the heat pump system according to the present invention is that the cooling water circulation path is provided with a cooling water pump capable of adjusting a flow rate per unit time of the cooling water,
When the state value is detected in the state value detecting step, the flow rate per unit time of the cooling water supplied to the third heat exchanger through the cooling water circulation path is set using the cooling water pump. The point is to make it less than the amount of water.

  According to the above characteristic configuration, the flow rate per unit time of the cooling water supplied to the third heat exchanger can be reduced below the set cooling water amount by the operation of the cooling water pump.

Still another characteristic configuration of the inspection method of the heat pump system according to the present invention is that the refrigerant circulation path includes a second bypass path through which the refrigerant can circulate bypassing the third heat exchanger and the second heat exchanger; A refrigerant distributor capable of adjusting a refrigerant distribution state to the second bypass path,
When detecting the state value in the state value detecting step, the flow rate per unit time of the refrigerant supplied to the third heat exchanger through the refrigerant circulation path is equal to or lower than the set refrigerant flow rate using the refrigerant distributor. It is in the point to make.

  According to the above characteristic configuration, when the flow rate per unit time of the refrigerant supplied to the third heat exchanger is reduced below the set refrigerant flow rate, in the third heat exchanger as the refrigerant evaporator, from the cooling water to the refrigerant The heat exchange performance against is reduced. For this reason, when the condensation pressure and the superheat degree of the refrigerant at the compressor inlet are approximately the same, the evaporation pressure decreases, and the heat pump cycle can be operated even when the engine exhaust heat ratio is small.

Still another characteristic configuration of the inspection method for the heat pump system according to the present invention is that the heat pump system includes a cooling water circulation path through which cooling water for recovering exhaust heat released from the engine circulates, and an outdoor fan for flowing outside air. With
In the cooling water circulation path, the cooling water after recovering the exhaust heat released from the engine branches and flows into the first flow path part and the second flow path part at the branch part, and the first flow path part and The cooling water can be circulated so as to collect the exhaust heat released from the engine again after the cooling water that has flowed through the second flow path portion merges at the merge portion.
In the middle of the second flow path portion, a fourth heat exchanger capable of performing heat exchange between the cooling water flowing through the second flow path portion and the outside air is provided,
In the third heat exchanger, heat exchange can be performed between the refrigerant flowing through the refrigerant circulation path and the cooling water flowing through the first flow path portion,
When the outdoor fan operates, the outside air after heat exchange with the refrigerant flowing through the refrigerant circulation path in the first heat exchanger is performed by cooling water flowing through the second flow path portion in the fourth heat exchanger. Flows to exchange heat,
When detecting the state value in the state value detecting step, the rotational speed of the outdoor fan is set so that the temperature difference between the cooling water before and after the heat exchange with the outside air in the fourth heat exchanger is within a set temperature difference. The point is to adjust.

  According to the above characteristic configuration, when the state value is detected in the state value detection step, the rotational speed of the outdoor fan is adjusted, and the cooling water is only subjected to a temperature change within the set temperature difference in the fourth heat exchanger. Return to the engine. That is, the exhaust heat of the engine recovered by the cooling water is hardly lost in the fourth heat exchanger. Therefore, even when it is necessary to flow a part of the cooling water to the fourth heat exchanger in order to reduce the heat exchange performance in the third heat exchanger, the engine exhaust heat can be prevented from being insufficient.

Still another characteristic configuration of the inspection method for the heat pump system according to the present invention is that the heat pump system includes an outdoor fan for flowing outside air, and the outside air flowing when the outdoor fan is operated is the first heat exchanger. And configured to exchange heat with the refrigerant flowing through the refrigerant circulation path,
When the state value is detected in the state value detecting step, the rotational speed of the outdoor fan is adjusted so that the condensation pressure of the refrigerant in the first heat exchanger becomes a target value.

Even if an operation command is given to the outdoor fan in order to exert a predetermined refrigerant condensing performance in the first heat exchanger, if the performance of the outdoor fan or the first heat exchanger changes due to aging, There is a possibility that the condensation performance of the refrigerant in one heat exchanger will change. In that case, the condensation pressure of the refrigerant in the first heat exchanger deviates from the target value.
However, in this feature configuration, when the state value is detected in the state value detection step, the rotational speed of the outdoor fan is adjusted so that the refrigerant condensing pressure in the first heat exchanger becomes the target value. It is ensured that the condensing pressure of the refrigerant in the vessel reaches the target value.

Still another characteristic configuration of the inspection method for the heat pump system according to the present invention is that the compression unit includes a plurality of compressors driven by the engine to compress refrigerant, and each of the plurality of compressors from the engine. A driving force transmission mechanism capable of adjusting the transmission state of the driving force to
When the state value is detected in the state value detecting step, the driving force transmission mechanism transmits the driving force of the engine only to some of the compressors of the plurality of compressors.

If the same flow rate of refrigerant flows through the refrigerant circuit, the more compressors that operate and the greater the total compressor displacement, the lower the engine speed (ie, the greater the torque) and the higher the operating compression. The smaller the number of machines and the smaller the total displacement volume of the compressor, the higher the rotational speed of the engine (ie, the smaller the torque). If the efficiency of each compressor is the same, the power required at this time is the same. Further, as engine characteristics, thermal efficiency tends to increase as torque increases, and thermal efficiency tends to decrease as torque decreases. Therefore, if the number of operating compressors is reduced, the thermal efficiency of the engine is reduced (engine exhaust heat efficiency is increased) as the rotational speed is increased (torque is reduced), and the exhaust heat ratio of the engine is increased.
Therefore, in this characteristic configuration, when the state value is detected in the state value detection step, the driving force transmission mechanism transmits the driving force of the engine only to some of the compressors out of the plurality of compressors. That is, the state value detection process can be performed in a state where the exhaust heat ratio of the engine is increased.

  Still another characteristic configuration of the inspection method of the heat pump system according to the present invention is that when the state value is detected in the state value detection step, the same rotation speed and torque as the rotation speed and torque of the engine during the inspection operation are detected. Compared to the case where the cooling operation is performed by torque, the engine is operated at an engine operation setting which can increase the exhaust heat ratio of the engine.

  According to the above characteristic configuration, the ignition timing retard and air ratio adjustment (lean degree reduction) etc. intentionally reduce the thermal efficiency and increase the engine exhaust heat ratio within a range that does not deteriorate the exhaust gas characteristics and combustion stability so much By making it, the fall degree of evaporation pressure can be suppressed.

Still another characteristic configuration of the inspection method for the heat pump system according to the present invention is that the amount of refrigerant staying is determined based on the volume of the section in which the refrigerant stays in the shut-off state and the density of the refrigerant staying in the section. A deriving refrigerant amount deriving step for deriving;
In the refrigerant charge amount determination step, the refrigerant charge amount existing in the refrigerant circulation path based on the comparison result between the state value detected in the state value detection step and a predetermined reference value and the amount of the retained refrigerant The point is to determine the suitability of the.

  According to the above characteristic configuration, the suitability of the refrigerant charging amount existing in the refrigerant circulation path is considered in consideration of the existence of the amount of the remaining refrigerant that is present in the refrigerant circulation path but is not circulating in the refrigerant circulation path during the inspection operation. Can be determined accurately.

  Still another characteristic configuration of the inspection method for the heat pump system according to the present invention is that the heat pump system is configured to be able to switch a circulation state of the refrigerant in the refrigerant circulation path by remote control.

  According to the above characteristic configuration, the refrigerant circulation state in the refrigerant circuit when the state value detection step is performed and the refrigerant circulation state in the refrigerant circuit when the state value detection step is not performed are switched by remote operation. be able to. As a result, when the state value detection process is performed, it is not necessary for the worker to go to the site.

The characteristic configuration of the heat pump system according to the present invention includes a refrigerant circulation path through which a refrigerant circulates, an engine, compression means that is driven by the engine and that flows through the refrigerant circulation path, and a refrigerant that flows through the refrigerant circulation path The first heat exchanger that can exchange heat between the outside air and the second heat that can exchange heat between the refrigerant flowing through the refrigerant circulation path and the heat exchange target fluid Heat exchange between the exchanger, the first expansion valve that expands the refrigerant flowing into the second heat exchanger, and the refrigerant flowing through the refrigerant circuit and the exhaust heat released from the engine. A third heat exchanger capable of expanding, a second expansion valve for expanding the refrigerant flowing into the third heat exchanger, and a control device,
In a state where the control device does not circulate the refrigerant via the second expansion valve and the third heat exchanger, the refrigerant sent from the compression means is the first heat exchanger, the first expansion valve, In the second heat exchanger acting as an evaporator, the refrigerant flows in the refrigerant circulation path by switching the refrigerant circulation state so as to return to the compression means after sequentially flowing through the second heat exchanger. A heat pump system capable of performing a cooling operation for cooling the heat exchange target fluid with a refrigerant,
In the shut-off state in which the control device does not circulate the refrigerant via the first expansion valve and the second heat exchanger, the refrigerant sent from the compression means is sent to the first heat exchanger and the second expansion valve. And the third heat exchanger in order, and then, based on the state value of the circulating refrigerant detected while performing the inspection operation by switching the circulating state of the refrigerant so as to be returned to the compression means The point is that the suitability of the refrigerant charge amount existing in the refrigerant circulation path is determined.

According to the above characteristic configuration, when the state value of the circulating refrigerant is detected while performing the inspection operation, the refrigerant sent from the compression means is the first heat exchanger, the second expansion valve, and the third heat exchanger. Are sequentially returned to the compression means, and the refrigerant is not circulated through the first expansion valve and the second heat exchanger used during the cooling operation. At this time, the refrigerant does not circulate in the second heat exchanger acting as an evaporator during cooling operation, but the heat between the refrigerant flowing through the refrigerant circulation path and the exhaust heat released from the engine in the third heat exchanger. By performing the exchange, the third heat exchanger acts as an evaporator in the heat pump cycle. Thus, when detecting the state value of the circulating refrigerant, the refrigerant circulates without passing through the second heat exchanger in which heat exchange with the heat exchange target fluid is performed. Therefore, the state of heat exchange in the second heat exchanger that changes according to the length of the refrigerant circulation path required to flow the refrigerant through the second heat exchanger, the temperature and the amount of the heat exchange target fluid, The state value of the circulating refrigerant can be accurately detected in a state where many factors that can change the state value of the refrigerant, such as the number of installed heat exchangers, are eliminated.
In addition, since the state value of the refrigerant being circulated is detected, it is easier to determine that the state has reached a steady state than when detecting the state value of the refrigerant while the circulation is stopped. It can be expected that the state value of the refrigerant is detected.

  Furthermore, even if the second heat exchanger is an indoor heat exchanger that exchanges heat with air in a room or the like, heat exchange (for example, cooling of the air in the room) is not performed in the indoor heat exchanger. Therefore, it is possible to prevent the cold air from being unexpectedly supplied to the living room while detecting the state value of the circulating refrigerant.

  Then, the control device can determine the suitability of the refrigerant charge amount existing in the refrigerant circulation path based on the comparison result between the accurate state value of the circulating refrigerant detected during the inspection operation and the predetermined reference value. . Therefore, it is possible to provide a heat pump system that can correctly recognize the refrigerant charge amount in the refrigerant circuit.

It is a figure which shows the structure of a heat pump system, and is a figure explaining the circulation state of the refrigerant | coolant when performing a cooling operation. It is a figure which shows the structure of a heat pump system, and is a figure explaining the circulation state of a refrigerant | coolant at the time of performing test | inspection driving | operation. It is a ph diagram of a heat pump system. It is a schematic diagram which shows the relationship between evaporation pressure and COPc. It is a schematic diagram which shows the correspondence of a refrigerant | coolant filling amount and a supercooling degree. It is a figure which shows another structure of a compression means. It is a figure explaining the circulation state of a refrigerant and cooling water. It is a figure explaining the circulation state of a refrigerant and cooling water. It is a figure which shows another structure of a heat pump system, and is a figure explaining the circulation state of a refrigerant | coolant at the time of performing a cooling operation. It is a figure which shows another structure of a heat pump system, and is a figure explaining the circulation state of a refrigerant | coolant when performing test | inspection driving | operation.

<First Embodiment>
A heat pump system inspection method according to a first embodiment of the present invention and a heat pump system configured to execute the inspection method will be described below with reference to the drawings.
FIG. 1 is a diagram illustrating a configuration of a heat pump system. Further, FIG. 1 shows the circulation state of the refrigerant and the cooling water when the cooling operation for cooling the air in the air-conditioning target space is performed in the heat pump system, and the flow path of the refrigerant and the cooling water is drawn with a bold solid line. ing. That is, the air in the air conditioning target space becomes the heat exchange target fluid. As shown, the heat pump system includes a refrigerant circulation path 3 through which refrigerant circulates, an engine 4, a compressor 5 that is driven by the engine 4 and compresses refrigerant flowing through the refrigerant circulation path 3, and refrigerant circulation. The first heat exchanger 8 capable of performing heat exchange between the refrigerant flowing through the passage 3 and the outside air, the refrigerant flowing through the refrigerant circulation passage 3, and the air in the air-conditioning target space (an example of “heat exchange target fluid”) ), A second heat exchanger 14 that can exchange heat with the indoor heat exchanger 14, a valve (first expansion valve) V1 that expands the refrigerant flowing into the indoor heat exchanger 14, and a refrigerant circulation path 3 A third heat exchanger 10 capable of performing heat exchange between the refrigerant and exhaust heat released from the engine 4, and a valve (second expansion valve) for expanding the refrigerant flowing into the third heat exchanger 10 ) V2. In addition, the heat pump system includes a control device 20.
In the following description, the first heat exchanger 8 is described as an outdoor heat exchanger, the second heat exchanger 14 is described as an indoor heat exchanger, and the third heat exchanger 10 is described. It may be described as a heat exchanger for exhaust heat recovery.

Furthermore, in the example shown in FIG. 1, the heat pump system also includes devices such as an oil separator 6, a four-way valve 7, and an accumulator 11. The oil separator 6 is provided to separate the oil component contained in the refrigerant and return it to the suction side of the compressor 5. The auxiliary circulation path 3 d connected to the oil separator 6 is used to return the oil component separated from the refrigerant to the compressor 5.
In the present embodiment, the indoor heat exchanger 14 and the valve V <b> 1 are accommodated in the housing 13 of the indoor unit 12, and other devices are accommodated in the housing 2 of the outdoor unit 1.

  The engine 4 is operated by consuming fuel such as natural gas. Then, the driving force of the engine 4 is transmitted to the compressor 5. Although not shown in FIG. 1, a power transmission mechanism such as a clutch that mediates transmission of driving force from the engine 4 to the compressor 5 may be provided. The control device 20 controls the operation of the engine 4 (for example, the rotational speed).

  The refrigerant sent out from the compressor 5 flows through the refrigerant circuit 3. In the middle of the refrigerant circulation path 3, various valves as described later are provided, and the circulation path of the refrigerant in the refrigerant circulation path 3 is switched by switching the open / close state of these valves. The switching of the refrigerant circulation path (that is, switching of the open / close state of various valves) is mainly controlled by the control device 20 by remote operation. For example, a command is given to the control device 20 from a server device (not shown) connected to the control device 20 via a communication line such as the Internet, and the control device 20 executes the command. The refrigerant circulation path is switched as described above.

[Refrigerant circuit 3]
The refrigerant circulation path 3 includes a main circulation path 3a that flows when the refrigerant sent from the compressor 5 circulates via the outdoor heat exchanger 8 and the indoor heat exchanger 14, and the refrigerant sent from the compressor 5. The secondary circulation paths 3b, 3c, 3d flow when circulating from the main circulation path 3a.

The main circulation path 3a (3) is composed of a compressor 5, an oil separator 6, a four-way valve 7, an outdoor heat exchanger 8, a valve V3, a valve V1, an indoor heat exchanger 14, a valve V4, a four-way valve 7 and an accumulator. 11 is a route that flows in order. In the present embodiment, the valve V3 and the valve V4 are accommodated in the housing 2 of the outdoor unit 1.
In the auxiliary circulation path 3b (3), the refrigerant branches off from the main circulation path 3a at the branch portion 50 between the outdoor heat exchanger 8 and the valve V3, and the valve V2 and the heat exchanger 10 for exhaust heat recovery are connected. This is a path that flows when the merging portion 51 between the four-way valve 7 and the accumulator 11 merges with the main circulation path 3a after flowing in sequence.
In the auxiliary circulation path 3c (3), the refrigerant branches from the main circulation path 3a at the branching portion 50 between the outdoor heat exchanger 8 and the valve V3, flows through the valve V5, and then performs heat exchange for exhaust heat recovery. This is a path that flows when joining the auxiliary circuit 3b between the vessel 10 and the accumulator 11.
The auxiliary circulation path 3d (3) is used when the refrigerant branches from the main circulation path 3a by the oil separator 6 and flows through the valve V6, and then joins the main circulation path 3a between the accumulator 11 and the compressor 5. It is a route that flows through.

[Cooling water circuit 15]
The heat released by operating the engine 4 is recovered by the cooling water flowing through the cooling water circulation path 15. A plurality of various valves as described later are provided in the middle of the cooling water circulation path 15, and the circulation path of the cooling water in the cooling water circulation path 15 is switched by switching the open / close state of these valves. Switching of the cooling water circulation path (that is, switching of the open / close state of various valves) is controlled by the control device 20 by remote control using a three-way valve or the like. When control is not required, a wax valve or the like whose opening / closing state is automatically adjusted according to temperature can be used.

  The cooling water circulation path 15 collects the first flow path portion 15 a that flows when the cooling water that has recovered the exhaust heat of the engine 4 circulates via the exhaust heat recovery heat exchanger 10 and the exhaust heat of the engine 4. The second flow path portion 15b flows when the cooling water circulates bypassing the first flow path portion 15a, the common flow path portion 15c that flows in common, and the detour path 15d. The first flow path portion 15 a and the second flow path portion 15 b are branched at the branch portion 18 and merged at the merge portion 16. A valve V7 as a cooling water distributor is provided at the branching portion 18 where the cooling water after recovering the exhaust heat of the engine 4 branches into the first flow path portion 15a and the second flow path portion 15b. A valve V8 is provided in the middle of the second flow path portion 15b between the branch portion 18 and the fourth heat exchanger 9. In the following description, the fourth heat exchanger 9 may be referred to as a heat dissipation heat exchanger.

The first flow path portion 15a reaches the junction 16 after the cooling water flows through the engine 4, the valve (cooling water distributor) V7, and the exhaust heat recovery heat exchanger 10, and passes through the common flow path portion 15c. The flow path flows when returning to the engine 4.
The second flow path portion 15b reaches the merging portion 16 after the cooling water flows through the engine 4, the valve (cooling water distributor) V7, the valve V8, and the heat dissipation heat exchanger 9, and the common flow path portion 15c passes through the common flow path portion 15c. It is a flow path that flows when returning to the engine 4 through.
The common flow path portion 15c is provided with a cooling water pump P1, and the cooling water flows into the cooling water circulation path 15 by operating the cooling water pump P1.
The detour circuit 15d is a flow path that flows when the cooling water circulates around the heat dissipation heat exchanger 9 by being diverted by the valve V8 in the middle of the second flow path portion 15b. The refrigerant flowing through the detour 15d is joined in the middle of the common flow path portion 15c.

  The heat exchanger 9 for heat dissipation is a device that can dissipate heat from the cooling water flowing through the second flow path portion 15b. The heat radiating heat exchanger 9 is provided with an outdoor fan F. When the outdoor fan F operates, the outside air taken into the outdoor unit 1 sequentially flows through the outdoor heat exchanger 8 and the heat dissipation heat exchanger 9, and is then discharged to the outside of the outdoor unit 1. That is, the outside air taken in by the outdoor fan F is first exchanged with the refrigerant flowing in the main circulation path 3a of the refrigerant circulation path 3 in the outdoor heat exchanger 8, and then in the heat dissipation heat exchanger 9 the cooling water circulation path 15 Heat exchange is performed with the cooling water flowing through the second flow path portion 15b.

[Cooling operation]
As shown in FIG. 1, the control device 20 performs a cooling operation in which the air in the air-conditioning target space is cooled by the refrigerant flowing through the indoor heat exchanger 14 while switching the refrigerant circulation state. In the figure, the paths through which the refrigerant and the cooling water flow are drawn with thick solid lines. In this case, the outdoor heat exchanger 8 acts as a condenser, and the indoor heat exchanger 14 acts as an evaporator.

  Specifically, the refrigerant sent from the compressor 5 flows into the oil separator 6 through the main circulation path 3 a of the refrigerant circulation path 3, and then reaches the four-way valve 7. The four-way valve 7 is switched so that the refrigerant sent from the compressor 5 first flows into the outdoor heat exchanger 8. Valve V3, valve V1, and valve V4 are opened. The valve V2 in the middle of the sub-circulation path 3b is closed, so that no refrigerant flows into the heat exchanger 10 for exhaust heat recovery in the sub-circulation path 3b, and the valve V5 in the middle of the sub-circulation path 3c. Is closed, the refrigerant does not flow into the auxiliary circulation path 3c. Therefore, the refrigerant sent out from the compressor 5 flows through the outdoor heat exchanger 8, the valve V 3, the valve V 1, the indoor heat exchanger 14, the valve V 4, the four-way valve 7, and the accumulator 11 in order, and then enters the compressor 5. Return. At this time, the valve V1 acts as an expansion valve, and the pressure of the refrigerant is reduced according to the opening degree to be set. Further, the valve V6 is adjusted at an appropriate opening degree according to the need for oil return.

  As described above, in the example shown in FIG. 1, the compressor 5 is not circulated through the valve (second expansion valve) V <b> 2 and the exhaust heat recovery heat exchanger (third heat exchanger) 10. The sent refrigerant flows through the outdoor heat exchanger (first heat exchanger) 8, the valve (first expansion valve) V 1, and the indoor heat exchanger (second heat exchanger) 14 in order, and then the compressor 5. In the indoor heat exchanger (second heat exchanger) 14 acting as an evaporator, the air in the air-conditioning target space (heat exchange target) is changed by the refrigerant flowing through the refrigerant circulation path 3 by switching the circulation state of the refrigerant so as to return to Cooling operation is performed to cool the fluid. In addition, although description is abbreviate | omitted, the heating operation which heats the air of the space for air-conditioning by changing the circulation direction of a refrigerant | coolant by switching the four-way valve 7 can also be performed.

When this cooling operation is performed, the control device 20 causes the cooling water recovered from the engine 4 in the cooling water circulation path 15 to flow into the second flow path portion 15 b and is cooled in the heat dissipation heat exchanger 9. Let the heat dissipate from the water. Specifically, the control device 20 causes the cooling water to flow through the common flow path portion 15c by operating the cooling water pump P1, and the total amount of the cooling water from which the exhaust heat is recovered from the engine 4 is the second flow path portion. The valve V7 is operated so as to flow to 15b, the valve V8 is operated so that the cooling water does not flow through the bypass 15d, and the outside air is introduced into the heat exchanger 9 for heat radiation, and heat is radiated from the cooling water. The outdoor fan F is operated so as to be performed. Further, when the control device 20 operates the outdoor fan F, outside air is also introduced into the outdoor heat exchanger 8.
Further, in order to set the temperature of the cooling water returning to the engine 4 to a predetermined temperature or to set the temperature of the cooling water discharged from the engine 4 to a predetermined temperature, a part of the cooling water is supplied to the first flow path portion 15a. Or the detour 15d. In the example shown in FIG. 1, a state in which a part of the cooling water flows through the first flow path portion 15a is shown.

[Inspection operation]
Next, an inspection method for the heat pump system will be described. This inspection method includes a state value detection step and a refrigerant filling amount determination step.

  FIG. 2 is a diagram illustrating a refrigerant circulation state when the state value detection step is performed in the heat pump system. Specifically, in the example shown in FIG. 2, the refrigerant sent from the compressor 5 flows into the oil separator 6 through the main circulation path 3 a of the refrigerant circulation path 3 and then reaches the four-way valve 7. The four-way valve 7 is switched so that the refrigerant sent from the compressor 5 first flows into the outdoor heat exchanger 8. At this time, the valve V1 and the valve V5 are closed, and the valve V2, the valve V3, and the valve V4 are opened. Therefore, the refrigerant sent out from the compressor 5 sequentially flows through the outdoor heat exchanger 8, the valve V2, the exhaust heat recovery heat exchanger 10, and the accumulator 11, and then returns to the compressor 5. At this time, the valve V2 acts as an expansion valve, and the pressure of the refrigerant is reduced according to the opening degree to be set. Further, the valve V6 is adjusted at an appropriate opening degree according to the need for oil return.

  When this inspection operation is being performed, the control device 20 causes the cooling water recovered from the engine 4 in the cooling water circulation path 15 to flow the cooling water from the engine 4 to the first flow path portion 15a, and the heat exchanger 10 for exhaust heat recovery. The heat is dissipated from the cooling water and the heat is transferred to the refrigerant flowing through the refrigerant circulation path 3. That is, in the heat exchanger 10 for exhaust heat recovery, heat exchange is performed between the cooling water that flows through the first flow path portion 15a of the cooling water circulation path 15 and the refrigerant that flows through the auxiliary circulation path 3b. The exhaust heat recovered from 4 is transmitted to the refrigerant. As a result, the exhaust heat recovery heat exchanger 10 can act as an evaporator that absorbs the exhaust heat recovered from the engine 4 into the refrigerant flowing in the sub-circulation path 3b. Specifically, the control device 20 causes the cooling water to flow through the common flow path portion 15c by operating the cooling water pump P1, and the cooling water that has recovered the exhaust heat from the engine 4 flows into the first flow path portion 15a. The valve V7 is operated so as to flow. The example shown in FIG. 2 shows the case where the entire amount of cooling water flows through the first flow path portion 15a and the common flow path portion 15c, but the temperature of the cooling water returning to the engine 4 is set to a predetermined temperature. Alternatively, in order to set the temperature of the cooling water discharged from the engine 4 to a predetermined temperature, a part of the cooling water may flow to the second flow path portion 15b or the detour 15d. In addition, the control device 20 operates the outdoor fan F so that outside air is introduced into the outdoor heat exchanger 8. Thus, in the inspection operation, the exhaust heat recovery heat exchanger 10 functions as an evaporator instead of the indoor heat exchanger 14 that functions as an evaporator in the cooling operation.

In the inspection method of the heat pump system, the state value detection step is performed from the compression means 5 in a shut-off state in which the refrigerant is not circulated via the valve (first expansion valve) V1 and the indoor heat exchanger (second heat exchanger) 14. The refrigerant is circulated in such a manner that the sent refrigerant is passed through the outdoor heat exchanger 8, the valve (second expansion valve) V2, and the exhaust heat recovery heat exchanger 10 in order, and then returned to the compression means 5. This is a step of detecting the state value of the circulating refrigerant while performing the inspection operation by switching.
The refrigerant filling amount determination step is a step of determining suitability of the refrigerant filling amount existing in the refrigerant circulation path 3 based on the state value detected in the state value detection step.
In this inspection method, when the refrigerant is newly filled in the refrigerant circuit 3, it is determined whether or not the refrigerant charging amount is appropriate, or after the refrigerant has been charged into the refrigerant circuit 3, the refrigerant circuit 3 It can be used to determine whether or not the amount of refrigerant in the refrigerant is appropriate (that is, whether or not refrigerant leaks from the refrigerant circulation path 3).

The transition from the refrigerant circulation state in the cooling operation shown in FIG. 1 to the refrigerant circulation state (blocking state) in the inspection operation shown in FIG. 2 can be performed by operating the valves as follows.
For example, during the cooling operation shown in FIG. 1, the valve V1 is opened at a predetermined opening, the valve V2 is closed, the valves V3 and V4 are opened, and the refrigerant is circulated with the valve V5 closed. I am letting. When the inspection operation shown in FIG. 2 is performed, the valve V1 is closed and the valve V2 is opened at a predetermined opening to circulate the refrigerant. Even in the inspection operation, the valve V3 and the valve V4 remain open and the valve V5 remains closed.

  Thus, the refrigerant circulation state in the refrigerant circulation path 3 when the state value detection step is performed (circulation state in FIG. 1) and the refrigerant circulation state in the refrigerant circulation path 3 when the state value detection step is not performed ( The circulation state in FIG. 2 can be switched by remote control of each valve by the control device 20. The switching of the cooling water circulation path from FIG. 1 to FIG. 2 can also be performed by remote control by the control device 20. When the cooling water valve is a wax valve or the like, the opening degree is automatically adjusted. As a result, when the state value detection process is performed, it is not necessary for the worker to go to the site.

  Then, the state value detection step is sent out from the compressor 5 while the refrigerant moving step is carried out and is maintained in a shut-off state in which the refrigerant is not circulated via the valve V1 and the indoor heat exchanger 14. The refrigerant is passed through the outdoor heat exchanger 8, the valve (second expansion valve) V2, and the exhaust heat recovery heat exchanger (third heat exchanger) 10 in this order, and then returned to the compressor 5. This is a step of detecting the state value of the circulating refrigerant by switching the circulation state of the refrigerant.

  FIG. 3 is a ph diagram of the heat pump system. In FIG. 3, a saturated liquid line and a saturated vapor line are drawn with a one-dot chain line, an isotherm is drawn with a broken line, a condensation temperature is 40 ° C., a supercooling degree is 5K (Kelvin), a superheating degree is 5K, and a compression efficiency is 75%. The value of each COPc (coefficient of performance during cooling) when the evaporation temperature is changed from −30 ° C. to 10 ° C. is shown. The refrigerant is R410A. Here, COPc shown in the figure is represented by “Δh2 / Δh1”, where Δh2 is the amount of heat necessary for evaporating the refrigerant and Δh1 is the power of the compressor 5. As shown in FIG. 3, the COPc (heat of evaporation / compression power) decreases as the evaporation temperature decreases. FIG. 4 is a schematic diagram showing the relationship between the evaporation pressure and COPc when the condensation temperature Tc is changed between 30 ° C. and 50 ° C. The refrigerant is R410A. At any condensation temperature, the COPc decreases as the evaporation pressure decreases, so that the heat pump cycle can be operated even when the heat balance when the engine shaft end efficiency is high, that is, when the engine exhaust heat ratio is small. That is, when detecting the state value in the state value detection step, the control device 20 performs the cooling operation by performing the cooling operation on the evaporating pressure in the exhaust heat recovery heat exchanger 10 of the circulating refrigerant by performing the inspection operation. It is preferable to lower the evaporation pressure of the circulating refrigerant in the indoor heat exchanger (second heat exchanger) 14. When the evaporation pressure decreases in the heat pump cycle, it means that the amount of heat necessary to evaporate the refrigerant with respect to the power for compressing the refrigerant becomes small, so the engine exhaust heat ratio is small. But the heat pump cycle can be operated.

The state value detected in the state value detection step is, for example, the degree of supercooling of the refrigerant. The degree of supercooling corresponds to a value obtained by subtracting the refrigerant temperature at the location from the condensation temperature that can be calculated from the pressure upstream of the expansion valve (valve V2) or downstream of the outdoor heat exchanger 8. For example, the pressure and temperature of the refrigerant on the downstream side of the outdoor heat exchanger 8 are measured at the position X in FIGS. 1 and 2, and the measured refrigerant temperature is subtracted from the condensation temperature that can be converted from the measured pressure. By doing so, the degree of supercooling of the refrigerant can be derived. Alternatively, at the position Y in FIGS. 1 and 2, the refrigerant pressure and temperature on the upstream side of the expansion valve (valve V2) are measured, and the measured refrigerant temperature is calculated from the condensing temperature that can be converted from the measured pressure. By subtracting, the degree of supercooling of the refrigerant can be derived.
FIG. 5 is a schematic diagram illustrating a correspondence relationship between the refrigerant charging amount and the degree of supercooling. As shown in the figure, it can be seen that the degree of supercooling decreases as the refrigerant charge amount decreases. That is, it can be seen that the amount of refrigerant charging can be determined using the degree of supercooling as the state value as an index.

Specifically, the control device 20 maintains a predetermined condensation temperature (for example, 40 ° C. or the like) in a ph diagram while being maintained in a shut-off state in which the refrigerant is not circulated via the valve V1 and the indoor heat exchanger 14. ) And a predetermined evaporation temperature (for example, −10 ° C., etc.), the degree of supercooling of the circulating refrigerant is detected while circulating the refrigerant by performing the above-described inspection operation. Then, the control device 20 stores the amount of the refrigerant filling amount based on the correspondence relationship between the degree of supercooling and the refrigerant filling amount stored in the storage device 30 in advance and the degree of supercooling detected in the state value detection step. And the degree thereof. For example, based on the correspondence example shown in FIG. 5, if the degree of supercooling detected in the state value detection step is 10K, the control device 20 determines that the refrigerant charging amount is 100% (reference amount). In contrast, if the degree of supercooling detected in the state value detection step is 2K, the control device 20 determines that the refrigerant charging amount is 80% (less than the reference amount), and if the degree of supercooling is 14K. It is determined that the refrigerant charging amount is 110% (more than the reference amount). Further, when the control device 20 indicates that the refrigerant filling amount existing in the refrigerant circuit 3 is smaller than the reference amount, the control device 20 is short of the refrigerant filling amount, or in the refrigerant circuit 3. As a result, it is possible to obtain a determination result that the refrigerant charging amount is not appropriate, such as that the refrigerant is leaking from.
As described above, in the present embodiment, the control device 20 converts the refrigerant sent from the compression unit 5 to the outdoor heat in a shut-off state in which the refrigerant is not circulated via the valve (first expansion valve) V1 and the indoor heat exchanger 14. After the exchanger 8, the valve (second expansion valve) V 2, and the exhaust heat recovery heat exchanger 10 are passed in order, the inspection operation is performed by switching the circulation state of the refrigerant so as to return to the compression means 5. On the basis of the detected state value of the circulating refrigerant, the suitability of the refrigerant charging amount existing in the refrigerant circulation path 3 is determined.

  As described above, in the inspection operation shown in FIG. 2, since the refrigerant circulates without passing through the indoor heat exchanger 14 where heat exchange with the air in the air-conditioning target space is performed, the refrigerant passes through the indoor heat exchanger 14. The length of the refrigerant circulation path 3 required for the refrigerant to flow, the state of heat exchange in the indoor heat exchanger 14 that changes according to the temperature and amount of air in the air-conditioning target space, the number of indoor heat exchangers 14 installed, etc. The state value of the circulating refrigerant can be detected in a state in which many of the factors that can change the state value of the refrigerant are eliminated.

  Next, specific contents of the inspection operation when the state value is detected in the state value detection step will be described.

[Adjusting the flow rate of cooling water supplied to the heat exchanger 10 for exhaust heat recovery in the inspection operation]
As described above, the heat pump system includes the cooling water circulation path 15 through which the cooling water for recovering the exhaust heat released from the engine 4 circulates. In the heat exchanger 10 for exhaust heat recovery, the refrigerant flowing through the refrigerant circulation path 3 Heat exchange with the cooling water flowing through the cooling water circulation path 15 can be performed.
When the controller 20 detects the state value in the state value detection step, the controller 20 sets the flow rate per unit time of the cooling water supplied to the exhaust heat recovery heat exchanger 10 through the cooling water circulation path 15. Below. In other words, when the flow rate per unit time of the cooling water supplied to the exhaust heat recovery heat exchanger 10 is reduced below the set cooling water amount, the exhaust heat recovery heat exchanger 10 as the refrigerant evaporator Therefore, the heat exchange performance with respect to the refrigerant decreases. For this reason, when the condensation pressure and the superheat degree of the refrigerant at the compressor inlet are approximately the same, the evaporation pressure decreases, and the heat pump cycle can be operated even when the engine exhaust heat ratio is small.

  Specifically, the cooling water circulation path 15 includes a first bypass path (second flow path portion 15b and detour path 15d) through which the cooling water can circulate bypassing the exhaust heat recovery heat exchanger 10, and the first bypass. It has the valve V7 and the valve V8 as a cooling water distributor which can adjust the distribution state of the cooling water to a channel | path (2nd flow-path part 15b, detour 15d). That is, as shown in FIG. 7, the control device 20 can distribute and flow the cooling water into the first flow path portion 15a and the second flow path portion 15b. Or although illustration is abbreviate | omitted, a cooling water can also be distributed and sent to the detour 15d.

  When the control device 20 detects the state value in the state value detection step, the flow rate of the cooling water supplied to the exhaust heat recovery heat exchanger 10 through the cooling water circulation path 15 per unit time, that is, the cooling The flow rate per unit time of the cooling water supplied to the heat exchanger 10 for exhaust heat recovery through the first flow path portion 15a of the water circulation path 15 is set using the cooling water distributor (valve V7, valve V8). It can be: For example, the control device 20 uses the valve V7 to supply cooling water to the first flow path portion 15a and the second flow path portion while maintaining a constant flow rate per unit time of the cooling water flowing through the common flow path portion 15c by the cooling water pump P1. The flow rate per unit time of the cooling water supplied to the heat exchanger 10 for exhaust heat recovery through the first flow path portion 15a of the cooling water circulation path 15 is distributed using the valve V7. The amount of cooling water can be set below the set amount.

  Alternatively, the cooling water circulation path 15 is provided with a cooling water pump P1 capable of adjusting the flow rate per unit time of the cooling water. Therefore, the control device 20 does not distribute the cooling water to the first flow path portion 15a and the second flow path portion 15b by the valve V7, but does not circulate the cooling water when detecting the state value in the state value detection step. The flow rate per unit time of the cooling water supplied to the heat exchanger 10 for exhaust heat recovery through the path 15 can be made equal to or less than the set cooling water amount using the cooling water pump P1.

[Adjusting the flow rate of the refrigerant supplied to the heat exchanger 10 for exhaust heat recovery in the inspection operation]
The refrigerant circulation path 3 includes a second bypass path (sub-circulation path 3c) through which the refrigerant can circulate by bypassing the exhaust heat recovery heat exchanger 10 and the indoor heat exchanger 14, and the second bypass path (sub-circulation path 3c). And a valve V5 as a refrigerant distributor capable of adjusting the refrigerant distribution state to the above. In the present embodiment, the valve V5 as the refrigerant distributor is an on-off valve provided in the middle of the auxiliary circulation path 3c or a valve capable of adjusting the on-off amount. Therefore, if the valve V5 is closed, the refrigerant is not distributed (does not flow) to the auxiliary circuit 3c, and if the valve V5 is opened, the refrigerant is distributed (flows) to the auxiliary circuit 3c. Moreover, if the opening / closing amount of the valve V5 is adjusted, the flow rate of the refrigerant flowing through the auxiliary circulation path 3c can be adjusted. In this way, as shown in FIG. 8, the control device 20 can distribute the refrigerant to the sub-circulation path 3 b and the sub-circulation path 3 c in the refrigerant circulation path 3. If the flow rate of the refrigerant flowing through the sub-circulation path 3c increases, the flow rate of the refrigerant flowing through the sub-circulation path 3b of the refrigerant circulation path 3 decreases, and if the flow rate of the refrigerant flowing through the sub-circulation path 3c decreases, The flow rate of the refrigerant flowing through the sub circulation path 3b of the refrigerant circulation path 3 increases. When the controller 20 detects the state value in the state value detection step, the flow rate per unit time of the refrigerant supplied to the exhaust heat recovery heat exchanger 10 through the refrigerant circulation path 3 is used as a refrigerant distributor. The flow rate of the refrigerant can be reduced below the set flow rate using the valve V5. That is, when the flow rate per unit time of the refrigerant supplied to the heat exchanger 10 for exhaust heat recovery is reduced to a set refrigerant flow rate or less, the heat exchanger 10 for exhaust heat recovery as an evaporator of the refrigerant uses the cooling water. The heat exchange performance with respect to the refrigerant decreases. Therefore, when the condensation pressure and the degree of superheat of the refrigerant at the compressor inlet are approximately the same, the evaporation pressure decreases, and the heat pump cycle can be operated even when the engine exhaust heat amount is small.

Second Embodiment
The specific contents of the inspection operation when the state value is detected in the state value detection step can be changed as appropriate. For example, the operation control of the outdoor fan F as described below may be performed.

As described above, the heat pump system includes the cooling water circulation path 15 through which the cooling water for recovering the exhaust heat released from the engine 4 circulates and the outdoor fan F that allows the outside air to flow. In the case shown in FIG. 7, in the cooling water circulation path 15, the cooling water after collecting the exhaust heat released from the engine 4 branches into the first flow path portion 15 a and the second flow path portion 15 b at the branch portion 18. So that the cooling water flowing through the first flow path portion 15a and the second flow path portion 15b merges at the merging portion 16 so that the exhaust heat released from the engine 4 is recovered again. It can be circulated. In the middle of the second flow path portion 15b of the cooling water circulation path 15, there is provided a heat dissipation heat exchanger 9 that can exchange heat between the cooling water flowing through the second flow path portion 15b and the outside air. It is done. When the outdoor fan F is operated, the outdoor air after heat exchange with the refrigerant flowing through the refrigerant circulation path 3 in the outdoor heat exchanger 8 becomes the cooling water and heat flowing through the second flow path portion 15b in the heat dissipation heat exchanger 9. Flow to exchange.
When the control device 20 detects the state value in the state value detection step, the outdoor fan is set so that the temperature difference between the cooling water before and after heat exchange with the outside air by the heat radiating heat exchanger 9 is within the set temperature difference. Adjust the rotation speed of F. In the present embodiment, the control device 20 has a coolant temperature upstream of the heat dissipation heat exchanger 9 measured by the temperature sensor T1 and a downstream side of the heat dissipation heat exchanger 9 measured by the temperature sensor T2. Based on the cooling water temperature, the temperature difference between the cooling water before and after heat exchange with the outside air by the heat-dissipating heat exchanger 9 can be derived.

  By performing such an operation, when the state value is detected in the state value detection step, the rotational speed of the outdoor fan F is adjusted, and the cooling water changes in temperature within a set temperature difference in the heat-dissipating heat exchanger 9. Return to the engine 4 just by receiving. That is, the exhaust heat of the engine 4 recovered by the cooling water is hardly lost in the heat dissipation heat exchanger 9. Therefore, in order to reduce the heat exchange performance in the heat exchanger 10 for exhaust heat recovery, even if it is necessary to flow a part of the cooling water to the heat exchanger 9 for heat dissipation, engine exhaust heat can be prevented from being insufficient. .

<Third Embodiment>
Even if an operation command is given to the outdoor fan F in order to exert a predetermined refrigerant condensing performance in the outdoor heat exchanger 8, if the performance of the outdoor fan F or the outdoor heat exchanger 8 changes due to aging, The refrigerant condensing performance in the outdoor heat exchanger 8 may change. In that case, the condensation pressure of the refrigerant in the outdoor heat exchanger 8 deviates from the target value.
Therefore, when detecting the state value in the state value detecting step, the control device 20 uses the outdoor heat exchanger 8 measured by a sensor (not shown) provided at the position X shown in FIGS. 1 and 2, for example. The rotational speed of the outdoor fan F is adjusted so that the condensing pressure of the refrigerant becomes the target value. Thus, when the state value is detected in the state value detection step, the rotational speed of the outdoor fan F is adjusted so that the refrigerant condensation pressure in the outdoor heat exchanger 8 becomes the target value. It is ensured that the condensation pressure of the refrigerant reaches the target value. At this time, the target value of the condensation pressure may be fixed or may be changed according to the outside air temperature.

<Fourth embodiment>
In the above embodiment, the example in which the compression unit 5 is configured by one compressor has been described, but the compression unit 5 may be configured by a plurality of compressors.
FIG. 6 is a diagram showing another configuration of the compression means 5. As shown in the figure, the compression means 5 includes a plurality of compressors that are driven by the engine 4 to compress the refrigerant, and a driving force that can adjust the transmission state of the driving force from the engine 4 to each of the plurality of compressors. A transmission mechanism 40 can also be provided. When the state value is detected in the state value detection step, the control device 20 causes the driving force transmission mechanism 40 to transmit the driving force of the engine 4 only to some of the compressors.

  In the example shown in FIG. 6, the compressing means 5 includes two compressors, a first compressor 5a and a second compressor 5b. The first compressor 5 a and the second compressor 5 b are provided in parallel in the refrigerant circulation path 3. The driving force of the engine 4 is transmitted to the first compressor 5a via the primary pulley 41, the belt 44, and the secondary pulley 42, and via the primary pulley 41, the belt 44, and the secondary pulley 43. It is transmitted to the second compressor 5b. A clutch 45 is provided between the secondary pulley 42 and the first compressor 5a, and a clutch 46 is provided between the secondary pulley 43 and the second compressor 5b. The primary pulley 41, the secondary pulley 42, the secondary pulley 43, the belt 44, the clutch 45, and the clutch 46 constitute a driving force transmission mechanism 40. And the control apparatus 20 can adjust the circulation amount of the refrigerant | coolant in the refrigerant | coolant circulation path 3 by switching the operation state of the clutch 45 and the clutch 46, and changing the operating number of compressors.

  If the same refrigerant flow rate is used, the number of operating compressors increases, and the larger the total displacement volume of the compression means 5, the lower the rotational speed of the engine 4 (that is, the greater the torque). The smaller the number and the smaller the total excluded volume of the compression means 5, the higher the rotational speed of the engine 4 (that is, the smaller the torque). If the efficiency of each compressor is the same, the power required at this time is the same. Further, as a characteristic of the engine 4, thermal efficiency tends to increase as torque increases, and thermal efficiency tends to decrease as torque decreases. Therefore, if the number of operating compressors is reduced, the thermal efficiency of the engine is lowered (engine exhaust heat efficiency is increased) as the rotational speed is increased (torque is reduced), and the exhaust heat ratio of the engine 4 is increased.

  Therefore, when detecting the state value in the state value detecting step, the control device 20 causes the driving force transmission mechanism 40 to transmit the driving force of the engine 4 only to some of the compressors. For example, in the example illustrated in FIG. 6, the control device 20 selects one of the compressor 5a and the compressor 5b, and the driving force of the engine 4 is transmitted only to the compressor. The driving force transmission mechanism 40 is operated. That is, the state value detection step can be performed with the exhaust heat ratio of the engine 4 increased.

<Fifth Embodiment>
The operation of the engine 4 when the cooling operation is performed may be different from the operation of the engine 4 when the inspection operation is performed.
Specifically, when the control device 20 detects the state value in the state value detection step, the control device 20 performs the cooling operation at the same rotation speed and torque with respect to the rotation speed and torque of the engine 4 during the inspection operation. The engine 4 may be operated with an engine operation setting that can increase the exhaust heat ratio of the engine 4.

  For example, the control device 20 intentionally lowers the thermal efficiency within a range in which the exhaust gas characteristics and the combustion stability are not deteriorated so much by retarding the ignition timing of the engine 4 and adjusting the air ratio (lean degree reduction). By increasing the heat rate, the degree of decrease in evaporation pressure can be suppressed. In other words, in normal cooling operation, the engine 4 is set so that the thermal efficiency of the engine 4 is as high as possible in consideration of exhaust gas (ignition timing, air ratio, etc.). Can be operated with a setting (delaying the ignition timing or reducing the lean degree of the air ratio) such that the thermal efficiency of the engine becomes low (the exhaust heat ratio increases).

<Sixth Embodiment>
Considering the amount of refrigerant remaining in the refrigerant circulation path 3 where the refrigerant is not circulated (refrigerant is accumulated) at the time of the inspection operation, whether or not the refrigerant charging amount existing in the refrigerant circulation path 3 is appropriate is determined. You may judge.

  Specifically, the control device 20 performs a staying refrigerant amount deriving step of deriving the staying refrigerant amount based on the volume of the section where the refrigerant stays in the shut-off state and the density of the refrigerant staying in the section. And in the refrigerant filling amount determination step, based on the comparison result between the state value detected in the state value detection step and the predetermined reference value, and the amount of retained refrigerant, the refrigerant filling amount existing in the refrigerant circulation path 3 Judge the suitability.

  More specifically, when the valve V1 is closed in order to switch from the cooling operation shown in FIG. 1 to the inspection operation shown in FIG. 2, the branching portion 50 and the merging portion 51 of the main circulation path 3a of the refrigerant circulation path 3 The refrigerant stays in the interval (hereinafter sometimes referred to as “retaining part”). At this time, a high-density liquid-phase refrigerant stays in the main circulation path 3a between the branch portion 50 and the valve V1, and the main circulation path 3a between the indoor heat exchanger 14 and the merge section has a density. A small vapor phase refrigerant stays. In the staying refrigerant amount deriving step of the present embodiment, the amount of liquid-phase refrigerant having a high density staying in the main circulation path 3a between the branch portion 50 and the valve V1 is derived. For example, if the volume of the main circulation path 3a in the section between the branch 50 and the valve V1 is known, the density of the refrigerant staying in this section is calculated by measuring the temperature and pressure of the refrigerant there. The amount of the remaining refrigerant remaining in the section between the branching portion 50 and the valve V1 can be derived. And the control apparatus 20 can perform correction | amendment of deriving | leading-out the refrigerant | coolant filling amount of the refrigerant circulation path 3 whole based on the derived | required refrigerant | coolant amount.

  Specifically, in the refrigerant filling amount determination step, the control device 20 calculates the refrigerant filling amount in the refrigerant circulation path 3 from the comparison result between the state value detected in the state value detection step and a predetermined reference value, and then stays there. Using the accumulated refrigerant amount derived in the refrigerant amount deriving step, the refrigerant charge amount of the entire refrigerant circulation path 3 including the accumulated portion is calculated, and refrigerant leakage is determined. For example, when the temperature of the refrigerant staying as described above is lower than the reference value, the density of the refrigerant increases, so that a refrigerant having a mass larger than the reference exists in the staying portion, and the refrigerant leaks. Even when there is no refrigerant, the refrigerant charging amount determining step determines that the refrigerant charging amount is less than the reference value. On the contrary, when the density of the refrigerant staying is low, there is a refrigerant with a mass less than the reference in the staying portion, and even if there is a refrigerant leak, the refrigerant filling amount determination step corresponds to the reference value. There is a possibility that the refrigerant charging amount is determined. However, such an influence can be suppressed by performing the correction of calculating the refrigerant filling amount of the entire refrigerant circulation path 3 including the staying portion by deriving the amount of the staying refrigerant as described above. In particular, this is effective when the distance between the outdoor unit 1 and the indoor unit 12 is long and the volume of the pipe serving as the staying portion becomes large. As described above, in consideration of the amount of the remaining refrigerant that is present in the refrigerant circulation path 3 but is not circulated through the refrigerant circulation path 3 at the time of the inspection operation, whether or not the refrigerant charging amount existing in the refrigerant circulation path 3 is appropriate. Can be determined accurately.

<Another embodiment>
<1>
In the said embodiment, although the specific example was given and demonstrated about the structure of the heat pump system, about the structure, it can change suitably.
For example, in the above-described embodiment, the cooling water circulation path 15 is configured by the first flow path portion 15a, the second flow path portion 15b, the common flow path portion 15c, and the detour path 15d, and an example in which valves are provided in various places has been described. However, those configurations can be changed as appropriate. A state without the detour 15d may be used.

  In addition, a heat exchanger may be additionally provided in the middle of the refrigerant circulation path 3. For example, FIG. 9 and FIG. 10 are diagrams showing another configuration of the heat pump system. Specifically, FIG. 9 is a diagram illustrating the circulation state of the refrigerant when performing the cooling operation, and FIG. 10 is a diagram illustrating the circulation state of the refrigerant when performing the inspection operation. In this example, the 5th heat exchanger 17 is provided in the middle of the main circuit 3a and the sub circuit 3c of the refrigerant circuit 3. Then, in the fifth heat exchanger 17, heat exchange is performed between the refrigerant existing in the main circulation path 3a and the refrigerant existing in the sub circulation path 3c. 9 and 10, the fifth heat exchanger 17 is installed between the branch portion 50 and the valve V3. However, the fifth heat exchanger 17 may be installed between the outdoor heat exchanger 8 and the branch portion 50. .

  In the cooling operation shown in FIG. 9, the refrigerant flows through the main circuit 3a, and the refrigerant flows through the sub circuit 3c by adjusting the valve V5 provided in the middle of the sub circuit 3c to a predetermined opening degree. As a result, the fifth heat exchanger 17 exchanges heat between the refrigerant flowing through the main circulation path 3a and the refrigerant flowing through the sub circulation path 3c. That is, the fifth heat exchanger 17 functions as a supercooler.

In the inspection operation shown in FIG. 10, the refrigerant does not flow into the main circulation path 3 a by closing the valve V <b> 1, but as described in the above embodiment, the branch part 50 and the merge part 51 of the main circulation path 3 a The refrigerant stays in between.
Further, as described in the above embodiment, in the inspection operation, the valve V5 provided in the middle of the auxiliary circulation path 3c is adjusted to a predetermined opening degree to be cooled in the auxiliary circulation path 3c and discharged during the inspection operation. The flow rate of the refrigerant supplied to the heat recovery heat exchanger 10 can also be adjusted. However, if the flow rate of the refrigerant supplied to the exhaust heat recovery heat exchanger 10 is not adjusted during the inspection operation, the valve V5 may be closed.

<2>
In the fourth embodiment, the heat pump system in which the plurality of compressors 5a and 5b are driven by the engine 4 has been described. For example, a heat pump system in which a part of the plurality of compressors 5a and 5b is driven by an electric motor. You may change to

<3>
In the above embodiment, the heat pump system includes the engine 4, whereby the driving force of the engine 4 is transmitted to the compressor 5, and the exhaust heat of the engine 4 is transferred to the exhaust heat recovery heat exchanger (third heat exchanger) 10. Although the given example has been described, a configuration in which the heat pump system includes a fuel cell and an electric motor instead of the engine 4 may be adopted. In this case, the electric motor operated by the power generated by the fuel cell drives the compressor 5, and the exhaust heat of the fuel cell is provided to the exhaust heat recovery heat exchanger 10.

<4>
In the above embodiment, the case where the state value detected in the state value detection step is the degree of supercooling of the refrigerant, but the change in the degree of supercooling according to the change in the refrigerant filling amount is p according to the refrigerant filling amount. It is merely an example of a change in the -h diagram, and a value different from the degree of supercooling as the state value, that is, a value appearing in a ph diagram different from the degree of supercooling may be used as the state value.

<5>
The configurations disclosed in the above-described embodiments (including the other embodiments, the same applies hereinafter) can be applied in combination with the configurations disclosed in the other embodiments as long as no contradiction arises, and are disclosed in this specification. The embodiment is an exemplification, and the embodiment of the present invention is not limited to this, and can be appropriately modified without departing from the object of the present invention.

  INDUSTRIAL APPLICABILITY The present invention can be used for an inspection method for a heat pump system that can correctly recognize the refrigerant charge amount in the refrigerant circuit.

3 Refrigerant circuit 4 Engine 5 Compressor (compression means)
5a Compressor 5b Compressor 8 Outdoor heat exchanger (first heat exchanger)
9 Heat exchanger for heat dissipation (4th heat exchanger)
10 Heat exchanger for exhaust heat recovery (3rd heat exchanger)
14 Indoor heat exchanger (second heat exchanger)
15 Cooling water circulation path 15a 1st flow path part 15b 2nd flow path part 15c Common flow path part 16 Merging part 20 Control device 40 Driving force transmission mechanism F Outdoor fan V1 valve (1st expansion valve)
V2 valve (second expansion valve)
V5 valve (refrigerant distributor)
V7 valve (cooling water distributor)
V8 valve (cooling water distributor)

Claims (14)

A refrigerant circulation path through which the refrigerant circulates, an engine, a compression unit that is driven by the engine and compresses the refrigerant flowing through the refrigerant circulation path, and performs heat exchange between the refrigerant flowing through the refrigerant circulation path and the outside air A first heat exchanger capable of generating heat, a second heat exchanger capable of performing heat exchange between the refrigerant flowing through the refrigerant circulation path and the heat exchange target fluid, and the second heat exchanger. A first expansion valve for expanding the refrigerant flowing in; a third heat exchanger capable of performing heat exchange between the refrigerant flowing through the refrigerant circuit and the exhaust heat released from the engine; A second expansion valve that expands the refrigerant flowing into the three heat exchangers,
The refrigerant sent from the compression means is not circulated through the second expansion valve and the third heat exchanger, and the refrigerant sent from the compression means is the first heat exchanger, the first expansion valve, and the second heat exchange. In the second heat exchanger acting as an evaporator, the heat exchange is performed by the refrigerant flowing through the refrigerant circulation path by switching the circulation state of the refrigerant so as to return to the compression means after sequentially flowing through the evaporator. An inspection method for a heat pump system capable of performing a cooling operation for cooling a target fluid,
In the shut-off state in which the refrigerant is not circulated via the first expansion valve and the second heat exchanger, the refrigerant sent from the compression means is used as the first heat exchanger, the second expansion valve, and the third heat. A state value detection step of detecting the state value of the circulating refrigerant while performing the inspection operation by switching the circulation state of the refrigerant so as to be returned to the compression means after sequentially flowing through the exchanger;
A method for inspecting a heat pump system, comprising: a refrigerant charge amount determination step for determining whether or not a refrigerant charge amount existing in the refrigerant circulation path is appropriate based on the state value detected in the state value detection step.   When the state value is detected in the state value detection step, the evaporating pressure of the circulating refrigerant in the third heat exchanger is performed by performing the inspection operation, and the circulating refrigerant is recovered by performing the cooling operation. The method for inspecting a heat pump system according to claim 1, wherein the inspection method is lower than an evaporation pressure in the second heat exchanger.   The heat pump system inspection method according to claim 1, wherein the state value is a degree of supercooling of the refrigerant. The heat pump system includes a cooling water circulation path through which cooling water for recovering exhaust heat released from the engine circulates, and in the third heat exchanger, the refrigerant flowing through the refrigerant circulation path and the cooling flowing through the cooling water circulation path Heat exchange with water,
When detecting the said state value in the said state value detection process, the flow rate per unit time of the cooling water supplied to the said 3rd heat exchanger through the said cooling water circulation path is made into below setting cooling water amount. The inspection method of the heat pump system as described in any one of 3. The cooling water circulation path includes a first bypass path through which the cooling water can circulate bypassing the third heat exchanger, and a cooling water distributor capable of adjusting a distribution state of the cooling water to the first bypass path. ,
When the state value is detected in the state value detection step, the flow rate per unit time of the cooling water supplied to the third heat exchanger through the cooling water circulation path is set using the cooling water distributor. The inspection method for the heat pump system according to claim 4, wherein the amount is less than or equal to the amount of water. The cooling water circulation path is provided with a cooling water pump capable of adjusting the flow rate per unit time of the cooling water,
When the state value is detected in the state value detecting step, the flow rate per unit time of the cooling water supplied to the third heat exchanger through the cooling water circulation path is set using the cooling water pump. The method for inspecting a heat pump system according to claim 4 or 5, wherein the amount is not more than the amount of water. The refrigerant circulation path includes a second bypass path through which the refrigerant can circulate bypassing the third heat exchanger and the second heat exchanger, and a refrigerant distribution capable of adjusting a distribution state of the refrigerant to the second bypass path. And
When detecting the state value in the state value detecting step, the flow rate per unit time of the refrigerant supplied to the third heat exchanger through the refrigerant circulation path is equal to or lower than the set refrigerant flow rate using the refrigerant distributor. The inspection method for the heat pump system according to any one of claims 1 to 6. The heat pump system includes a cooling water circulation path through which cooling water for recovering exhaust heat released from the engine circulates, and an outdoor fan for flowing outside air,
In the cooling water circulation path, the cooling water after recovering the exhaust heat released from the engine branches and flows into the first flow path part and the second flow path part at the branch part, and the first flow path part and The cooling water can be circulated so as to collect the exhaust heat released from the engine again after the cooling water that has flowed through the second flow path portion merges at the merge portion.
In the middle of the second flow path portion, a fourth heat exchanger capable of performing heat exchange between the cooling water flowing through the second flow path portion and the outside air is provided,
In the third heat exchanger, heat exchange can be performed between the refrigerant flowing through the refrigerant circulation path and the cooling water flowing through the first flow path portion,
When the outdoor fan operates, the outside air after heat exchange with the refrigerant flowing through the refrigerant circulation path in the first heat exchanger is performed by cooling water flowing through the second flow path portion in the fourth heat exchanger. Flows to exchange heat,
When detecting the state value in the state value detecting step, the rotational speed of the outdoor fan is set so that the temperature difference between the cooling water before and after the heat exchange with the outside air in the fourth heat exchanger is within a set temperature difference. The inspection method of the heat pump system according to any one of claims 1 to 7, which is adjusted. The heat pump system includes an outdoor fan that causes the outside air to flow, and the outside air that flows when the outdoor fan operates is configured to exchange heat with the refrigerant that flows through the refrigerant circulation path in the first heat exchanger.
8. The rotation speed of the outdoor fan is adjusted so that the condensation pressure of the refrigerant in the first heat exchanger becomes a target value when the state value is detected in the state value detection step. The inspection method for the heat pump system according to one item. The compression means includes a plurality of compressors driven by the engine to compress the refrigerant, and a driving force transmission mechanism capable of adjusting a transmission state of the driving force from the engine to each of the plurality of compressors. Prepared,
The driving force transmission mechanism transmits the driving force of the engine only to some of the compressors of the plurality of compressors when detecting the state value in the state value detecting step. The inspection method of the heat pump system as described in any one of Claims 9.   When the state value is detected in the state value detection step, the exhaust heat of the engine is larger than when the cooling operation is performed at the same rotation speed and torque as the rotation speed and torque of the engine during the inspection operation. The inspection method of the heat pump system according to any one of claims 1 to 10, wherein the engine is operated with an engine operation setting capable of increasing a ratio. A residence refrigerant amount deriving step for deriving the amount of residence refrigerant based on the volume of the section in which the refrigerant stays in the shut-off state and the density of the refrigerant staying in the section;
In the refrigerant charge amount determination step, the refrigerant charge amount existing in the refrigerant circulation path based on the comparison result between the state value detected in the state value detection step and a predetermined reference value and the amount of the retained refrigerant The inspection method for a heat pump system according to any one of claims 1 to 11, wherein the suitability is determined.   The heat pump system inspection method according to any one of claims 1 to 12, wherein the heat pump system is configured to be able to switch a circulation state of the refrigerant in the refrigerant circulation path by a remote operation. A refrigerant circulation path through which the refrigerant circulates, an engine, a compression unit that is driven by the engine and compresses the refrigerant flowing through the refrigerant circulation path, and performs heat exchange between the refrigerant flowing through the refrigerant circulation path and the outside air A first heat exchanger capable of generating heat, a second heat exchanger capable of performing heat exchange between the refrigerant flowing through the refrigerant circulation path and the heat exchange target fluid, and the second heat exchanger. A first expansion valve for expanding the refrigerant flowing in; a third heat exchanger capable of performing heat exchange between the refrigerant flowing through the refrigerant circuit and the exhaust heat released from the engine; A second expansion valve for expanding the refrigerant flowing into the three heat exchangers, and a control device;
In a state where the control device does not circulate the refrigerant via the second expansion valve and the third heat exchanger, the refrigerant sent from the compression means is the first heat exchanger, the first expansion valve, In the second heat exchanger acting as an evaporator, the refrigerant flows in the refrigerant circulation path by switching the refrigerant circulation state so as to return to the compression means after sequentially flowing through the second heat exchanger. A heat pump system capable of performing a cooling operation for cooling the heat exchange target fluid with a refrigerant,
In the shut-off state in which the control device does not circulate the refrigerant via the first expansion valve and the second heat exchanger, the refrigerant sent from the compression means is sent to the first heat exchanger and the second expansion valve. And the third heat exchanger in order, and then, based on the state value of the circulating refrigerant detected while performing the inspection operation by switching the circulating state of the refrigerant so as to be returned to the compression means A heat pump system for determining the suitability of the refrigerant filling amount existing in the refrigerant circulation path.

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