Heat exchange system

Abstract

To provide a heat exchange system 1 which efficiently transmits latent heat of condensation of a refrigerant in a water refrigerant heat exchanger 12 to hot water.SOLUTION: A heat exchange system 1 includes a hot water circuit 2 having: an electric heater 13 which heats hot water which has absorbed heat from a refrigerant in a water refrigerant heat exchanger 12; and a heating heater 10 which radiates heat from the hot water heated by the electric heater 13 to a passenger compartment 30. The electric heater 13 is disposed at a hot water passage 17a of a hot water passage 16a and the hot water passage 17a. In the hot water circuit 2, hot water flows through the electric heater 13, the heating heater 10, the water refrigerant heat exchanger 12, and the electric heater 13 in a written order and thereby circulates through the hot water passage 16a and the hot water passage 17a. A compressor 20 allows the refrigerant having a temperature higher than that of the hot water flowing from the heating heater 10 into the water refrigerant heat exchanger 12 to flow into the water refrigerant heat exchanger 12. The refrigerant has refrigerant saturation vapor pressure of 2 MPa or higher at an absolute pressure when a refrigerant temperature is 60°C.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a heat exchange system. [Background technology]

[0002] 2. Description of the Related Art Conventionally, a refrigeration cycle apparatus has been proposed that includes a compressor that compresses a refrigerant and a water-refrigerant heat exchanger in which the refrigerant discharged from the compressor is condensed and dissipates heat from the refrigerant to hot water (see, for example, Patent Document 1).

[0003] The refrigeration cycle device is provided with a pressure reducing valve that reduces the pressure of the refrigerant that has passed through the water-refrigerant heat exchanger, and an evaporator that evaporates the refrigerant reduced in pressure by the pressure reducing valve. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2015-210054 A Summary of the Invention [Problem to be solved by the invention]

[0005] The inventors have considered using a refrigeration refrigerant in the above-mentioned refrigeration cycle device and configuring a hot water circuit using a hot water heater in which hot water heated by the refrigerant in the water-refrigerant heat exchanger heats the air in the vehicle cabin, and a water-refrigerant heat exchanger.

[0006] For example, in order to efficiently heat hot water, it is desirable to heat the hot water discharged from the hot water heater only by heat radiation from the refrigerant in the water-refrigerant heat exchanger, thereby bringing the hot water temperature closer to a target temperature.

[0007] In this case, the water-refrigerant heat exchanger needs to condense the refrigerant at a temperature higher than the temperature of the hot water flowing into the water-refrigerant heat exchanger from the hot water heater. Generally, the refrigerant for refrigeration has a higher refrigerant pressure when condensing than the refrigerant for air conditioning.

[0008] Furthermore, in a refrigeration cycle device using a refrigeration refrigerant, when a water-refrigerant heat exchanger that heats hot water by heat radiation from the refrigerant is used as a condenser, it is necessary to operate the device so that the condensation pressure of the refrigerant is higher than when an air-conditioning refrigerant is used.

[0009] However, in a refrigeration cycle device that uses a refrigerating refrigerant, when hot water is heated in a water-refrigerant heat exchanger, if the power consumption by the electric compressor is limited, the pressure of the high-pressure refrigerant discharged from the electric compressor cannot be sufficiently increased.

[0010] For this reason, the condensation temperature of the refrigerant in the water-refrigerant heat exchanger cannot be made sufficiently high, and the hot water temperature cannot approach the target temperature simply by heat dissipation from the refrigerant in the water-refrigerant heat exchanger.

[0011] In addition, when the pressure of the high-pressure refrigerant rises due to a disturbance or the like and exceeds the upper limit, it is necessary to implement pressure protection control to lower the high-pressure refrigerant by controlling the compressor, etc. For this reason, the condensation temperature of the refrigerant in the water-refrigerant heat exchanger cannot be sufficiently high, and the hot water temperature cannot be brought close to the target temperature by heat radiation from the refrigerant alone.

[0012] Therefore, it is necessary to use a heating device such as an electric heater to heat the hot water in addition to the water-refrigerant heat exchanger. However, depending on the arrangement of the water-refrigerant heat exchanger and the heating device, it may not be possible to transfer the heat radiated from the refrigerant in the water-refrigerant heat exchanger to the hot water at all.

[0013] In view of the above, an object of the present disclosure is to provide a heat exchange system in which the latent heat of condensation of a refrigerant is transferred to a heat medium in a heat exchanger corresponding to a water-refrigerant heat exchanger. [Means for solving the problem]

[0014] According to one aspect of the disclosure, a heat exchange system includes: a refrigeration cycle device (3) including a compressor (20) which draws in a refrigerant through a suction port (20a), compresses it, and discharges it from a discharge port (20b), and a heat exchanger (12) which heats a heat medium by the latent heat of condensation of the refrigerant when the refrigerant discharged from the discharge port is condensed, the refrigerant which has passed through the heat exchanger is introduced to the suction port to circulate the refrigerant, and which constitutes a vapor compression refrigeration cycle using a refrigerant whose refrigerant saturated vapor pressure is 2 MPa or more in absolute pressure when the refrigerant temperature is 60° C. when the refrigerant is condensed; a heat medium circuit (2) including a heater device (13) that heats a heat medium that has absorbed heat from a refrigerant in a heat exchanger, and a heat dissipation device (10) that dissipates heat from the heat medium heated by the heater device to a heat dissipation target (30); In the case where a flow path through which a heat medium flows from a heat medium outlet (10b) of a heat radiating device to a heat medium inlet (12a) of a heat exchanger is defined as a first heat medium flow path (16a), and a flow path through which a heat medium flows from the heat medium outlet (12b) of the heat exchanger to the heat medium inlet (10a) of a heat radiating device is defined as a second heat medium flow path (17a), the heater device is disposed in the second heat medium flow path of the first heat medium flow path and the second heat medium flow path; In the heat medium circuit, the heat medium flows in the order of the heater device, the heat radiating device, the heat exchanger, and the heater device, so that the heat medium circulates through the first heat medium flow path and the second heat medium flow path.

[0015] For example, when a heater device heats hot water that has passed through a heat dissipation device prior to the heat exchanger, the temperature of the heat medium flowing into the heat exchanger may be higher than the temperature of the refrigerant flowing into the heat exchanger from the compressor, and the heat medium may not be able to be heated by the refrigerant in the heat exchanger.

[0016] In contrast to this, according to one aspect of the present disclosure, as described above, in the heat medium circuit, the heat medium flows in the order of the heater device, the heat dissipation device, the heat exchanger, and the heater device, so that the heat medium circulates through the first heat medium flow path and the second heat medium flow path.

[0017] Therefore, the heat exchanger heats the hot water that has passed through the heat dissipation device prior to the heater device, making it possible to provide a heat exchange system in which the heat of the refrigerant is efficiently transferred to the heat medium in the heat exchanger.

[0018] According to another aspect of the present disclosure, a heat exchange system includes: a heat medium circuit (2) including a heater device (13) that heats a heat medium, a heat radiating device (10) that radiates heat from the heat medium heated by the heater device to a heat radiating target (30), a first heat medium piping (80) that guides the heat medium discharged from a heat medium outlet (10b) of the heat radiating device to a heat medium inlet (13a) of the heater device, and a second heat medium piping (81) that guides the heat medium that has passed through the first heat medium piping to the heat medium inlet (81a) of the heater device, wherein the heat medium outlet (80a) of the first heat medium piping and the heat medium inlet (81a) of the second heat medium piping are configured to be detachable, A heat exchanger (12) is disposed between the heat medium outlet (80a) of the first heat medium piping and the heat medium inlet (81a) of the second heat medium piping. When a heat exchanger is disposed between the heat medium outlet of the first heat medium piping and the heat medium inlet of the second heat medium piping, The heat exchanger forms a vapor compression refrigeration cycle in which a heat medium is heated by the latent heat of condensation of the refrigerant discharged from a compressor (20) that draws in, compresses, and discharges the refrigerant, and the refrigerant is circulated together with the compressor. In the vapor compression refrigeration cycle, a refrigerant with an absolute saturation pressure of 2 MPa or more is used when the refrigerant temperature is 60°C during condensation. When a flow path through which the heat medium flows from the heat medium outlet (10b) of the heat radiating device to the heat medium inlet (12a) of the heat exchanger is defined as a first heat medium flow path (16a), and a flow path through which the heat medium flows from the heat medium outlet (12b) of the heat exchanger to the heat medium inlet (10a) of the heat radiating device is defined as a second heat medium flow path (17a), the heater device is disposed in the second heat medium flow path of the first heat medium flow path and the second heat medium flow path; In the heat medium circuit, the heat medium flows in the order of the heater device, the heat radiating device, the heat exchanger, and the heater device, so that the heat medium circulates through the first heat medium flow path and the second heat medium flow path.

[0019] Therefore, by removing the connecting hose from the heat medium outlet of the first heat medium piping and the heat medium inlet of the second heat medium piping, the heat exchanger can be easily disposed at the correct position in the heat medium circuit.

[0020] The reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and specific components described in the embodiments described below. [Brief description of the drawings]

[0021] [Figure 1] 1 is a diagram showing an overall configuration of a hot water circuit and a refrigeration cycle device for refrigeration of a heat exchange system of an electric refrigeration vehicle in a first embodiment of the present disclosure. [Diagram 2] 4 is a flowchart showing details of a hot water control process performed by the air conditioning control device in the first embodiment of FIG. 1. [Diagram 3] FIG. 2 is a Mollier curve showing the relationship between refrigerant pressure and enthalpy in the refrigeration cycle device for refrigeration in the first embodiment of FIG. 1, and is used to assist in the explanation of the characteristics of the refrigerant used in the refrigeration cycle device. [Figure 4] FIG. 2 is a diagram for assisting in the explanation of the refrigeration refrigerant used in the refrigeration cycle device for refrigeration in the first embodiment of FIG. 1, and is a diagram showing the refrigerant saturated vapor pressure and refrigerant temperature at the time of condensation of the refrigeration refrigerant and the air conditioning refrigerant, respectively. [Diagram 5] FIG. 11 is a diagram showing the overall configuration of a hot water circuit and a refrigeration cycle device for refrigeration in a heat exchange system of an electric refrigeration vehicle in a second embodiment of the present disclosure. [Figure 6] 13 is a flowchart for illustrating a manufacturing process of the heat exchange system of the electric refrigeration vehicle in the third embodiment of the present disclosure. [Figure 7] FIG. 7 is a diagram showing the configuration of a hot water circuit installed in an electric refrigerated car of an automobile manufacturer, in the heat exchange system according to the third embodiment of FIG. 6. [Figure 8]FIG. 8 is an enlarged view of a portion VIII of the hot water circuit in FIG. 7, and is a view for assisting in the explanation of a connecting hose connected to the hot water circuit. [Figure 9] FIG. 7 is a diagram showing the overall configuration of a hot water circuit and a refrigeration cycle device for refrigeration mounted in an electric refrigeration vehicle by a refrigeration vehicle manufacturer in the third embodiment of FIG. 6, and a state in which the hot water circuit and the refrigeration cycle device for refrigeration are connected. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings for the sake of simplicity of description.

[0023] (First embodiment) FIG. 1 shows a first embodiment of a heat exchange system 1 for an electric refrigeration vehicle according to the present disclosure.

[0024] 1, a heat exchange system 1 of the present embodiment includes a hot water circuit 2 and a refrigeration cycle device 3 for refrigeration. The hot water circuit 2 is a heat medium circuit including a heater 10, a pump 11, a water-refrigerant heat exchanger 12, an electric heater 13, a temperature sensor 14, an air conditioning control device 15, and hot water pipes 16 and 17.

[0025] The hot water piping 16 constitutes a hot water flow path (i.e., a first heat medium flow path) 16a that guides hot water flowing out from a hot water outlet (i.e., a heat medium outlet) 10b of the heater 10 to a hot water inlet (i.e., a heat medium inlet) 12a of the water-refrigerant heat exchanger 12.

[0026] The hot water pipe 17 constitutes a hot water flow path (i.e., a second heat medium flow path) 17a that guides hot water flowing out from a hot water outlet (i.e., a heat medium outlet) 12b of the water-refrigerant heat exchanger 12 to a hot water inlet (i.e., a heat medium inlet) 10a of the heater 10. The hot water is a heat medium constituted by mixing antifreeze or the like with water.

[0027] The heater 10 is a heat exchanger that exchanges heat between hot water flowing in from the hot water flow path 17a through the hot water inlet 10a and the air inside the passenger compartment (i.e., the target for heat dissipation) 30 of the refrigerated vehicle. Hereinafter, the air inside the passenger compartment 30 is also referred to as inside air. The heater 10 is a heat dissipation device that dissipates heat from the hot water flowing in through the hot water inlet 10a to the inside air. In this way, the heater 10 heats the passenger compartment 30 with the hot water.

[0028] The pump 11 is disposed in the hot water flow path 16a. The pump 11 draws hot water from a hot water inlet 10a of the heater 10 and discharges it toward a hot water inlet 12a of the water-refrigerant heat exchanger 12 by rotation of its impeller.

[0029] In this embodiment, an electric pump having an impeller driven by an electric motor is adopted as the pump 11. The electric motor of the pump 11 is driven by electric power supplied from an on-board battery.

[0030] The water-refrigerant heat exchanger 12 is a heat exchanger that exchanges heat between the high-pressure refrigerant discharged from the compressor 20 and the hot water flowing in from the pump 11. The water-refrigerant heat exchanger 12 heats the hot water flowing in from the pump 11 by the latent heat of condensation and the sensible heat of the high-pressure refrigerant discharged from the compressor 20.

[0031] The electric heater 13 is a first heater device disposed in the hot water flow path 17a. The electric heater 13 heats the hot water flowing from the water-refrigerant heat exchanger 12 by using power supplied from an on-board battery. The temperature sensor 14 is a temperature detection unit that detects the temperature of the hot water heated by the electric heater 13.

[0032] The temperature sensor 14 in this embodiment is disposed in the hot water flow path 17a on the hot water inlet 10a side of the heater 10. This allows the temperature sensor 14 to detect the hot water temperature in the heater 10. As the temperature sensor 14, for example, a thermistor is used.

[0033] The air conditioning control device 15 is an electronic control device composed of a microcomputer, a memory, etc. As a temperature control unit, the air conditioning control device 15 executes water temperature control processing according to a computer program pre-recorded in the memory.

[0034] As the water temperature control process is executed, the air conditioning control device 15 controls the electric heater 13 based on the temperature detected by the temperature sensor 14 to adjust the amount of heat radiated from the electric heater 13 to the hot water. This causes the hot water temperature on the hot water inlet 10a side of the heater 10 in the hot water flow path 17a to approach the target temperature.

[0035] In other words, the air conditioning control device 15 controls the electric heater 13 based on the temperature detected by the temperature sensor 14, and adjusts the amount of heat radiated from the electric heater 13 to the hot water so that the temperature of the hot water in the heating heater 10 approaches the target temperature.

[0036] The refrigeration cycle apparatus 3 for refrigeration cools the air inside the freezer 40 by a refrigerant. Specifically, the refrigeration cycle apparatus 3 for refrigeration includes a water-refrigerant heat exchanger 12, a compressor 20, a condenser 21, an electric fan 21a, a pressure reducing valve 22, an evaporator 23, an electric fan 23a, and a refrigeration control device 24, as shown in FIG.

[0037] The compressor 20 draws in a refrigerant from a suction port 20a by driving the compression mechanism, compresses it, and discharges it from a discharge port 20b. The compressor 20, together with a condenser 21, a pressure reducing valve 22, and an evaporator 23, constitute a vapor compression refrigeration cycle that circulates the refrigerant.

[0038] In this embodiment, an electric compressor in which a compression mechanism for compressing a refrigerant is driven by an electric motor is used as the compressor 20. The electric motor of the compressor 20 is driven by electric power supplied from an on-board battery.

[0039] The water-refrigerant heat exchanger 12 condenses the refrigerant by dissipating heat from the refrigerant discharged from the compressor 20 to the hot water flowing in from the pump 11. The water-refrigerant heat exchanger 12 heats the hot water flowing from the pump 11 by the latent heat of condensation and sensible heat of the refrigerant. The condenser 21 is disposed outside the freezer 40 and outside the passenger compartment 30. The condenser 21 is an exterior heat exchanger that exchanges heat between the high-pressure refrigerant that has passed through the water-refrigerant heat exchanger 12 and the outside air.

[0040] The condenser 21 dissipates heat to the outside air from the high-pressure refrigerant that has passed through the water-refrigerant heat exchanger 12. The outside air is air that is present outside the freezer 40 and outside the vehicle compartment 30. The electric fan 21a is disposed outside the freezer 40 and outside the vehicle compartment 30.

[0041] The electric fan 21a has an impeller rotated by an electric motor, thereby generating a flow of outside air passing through the condenser 21. The electric motor of the electric fan 21a is driven by power supplied from an on-board battery.

[0042] The pressure reducing valve 22 is a pressure reducing valve that reduces the pressure of the refrigerant that has passed through the condenser 21. The evaporator 23 is an evaporator in which the low-pressure refrigerant that has passed through the pressure reducing valve 22 absorbs heat from the air inside the freezer 40.

[0043] The evaporator 23 and the electric fan 23a are each disposed inside the freezer 40. The electric fan 23a generates an airflow that passes through the evaporator 23 inside the freezer 40 by rotating its impeller with an electric motor.

[0044] This causes the air inside the freezer 40 to be cooled by heat absorption by the refrigerant in the evaporator 23. The electric motor of the electric fan 23a is driven by power supplied from the vehicle battery.

[0045] The refrigeration control device 24 is an electronic control device composed of a microcomputer and a memory. The refrigeration control device 24 controls the pressure of the high-pressure refrigerant in the water-refrigerant heat exchanger 12 by controlling the electric motor of the compressor 20 and the electric motor of the electric fan 21a. In this way, the temperature of the high-pressure refrigerant flowing into the water-refrigerant heat exchanger 12 approaches a target temperature.

[0046] Next, the operation of the heat exchange system 1 of this embodiment will be described.

[0047] First, in the hot water circuit 2, the pump 11 rotates an impeller by the electric motor supplied with power from the vehicle battery. As a result, the pump 11 draws hot water from the heater 10 through the hot water outlet 10b and discharges the drawn hot water toward the hot water inlet 12a of the water-refrigerant heat exchanger 12.

[0048] As a result, hot water flows in the order of heater 10, pump 11, water-refrigerant heat exchanger 12, electric heater 13, and heater 10. Therefore, hot water discharged from pump 11 circulates through hot water flow paths 17a and 16a.

[0049] The water-refrigerant heat exchanger 12 condenses the refrigerant by dissipating heat from the refrigerant discharged from the compressor 20 to the hot water flowing in from the pump 11. The water-refrigerant heat exchanger 12 heats the hot water flowing in from the pump 11 with the latent heat of condensation and sensible heat of the high-pressure refrigerant discharged from the compressor 20. This heated hot water flows into the electric heater 13. The electric heater 13 heats the hot water heated by the water-refrigerant heat exchanger 12 with power supplied from the vehicle battery.

[0050] The hot water heated by the electric heater 13 flows into the space heater 10. The space heater 10 dissipates heat from the hot water heated by the electric heater 13 to the inside air. This allows the space heater 10 to heat the vehicle interior 30 with the hot water. The hot water that has passed through the space heater 10 flows through the pump 11 to the hot water inlet 12a of the water-refrigerant heat exchanger 12.

[0051] At this time, the air conditioning control device 15 executes a water temperature control process in accordance with the flowchart of Fig. 2. Fig. 4 is a flowchart showing the details of the water temperature control process.

[0052] First, the air conditioning control device 15 detects the temperature of the hot water in the heater 10 by the temperature sensor 14 in step S100.

[0053] Next, in step S110, the air conditioning control device 15 determines whether the water temperature in the heater 10 detected in step S100 is lower than a target temperature (for example, 60° C.).

[0054] At this time, in step S110, the air conditioning control device 15 determines YES when the water temperature in the heater 10 is lower than the target temperature (for example, 60° C.). Accordingly, in step S120, the air conditioning control device 15 turns on the heater 10. As a result, the hot water flowing in from the water-refrigerant heat exchanger 12 is heated by the electric heater 13.

[0055] On the other hand, in step S110, when the water temperature in the heater 10 is equal to or higher than the target temperature, the air conditioning control device 15 judges NO. Accordingly, in step S130, the air conditioning control device 15 turns off the heater 10. As a result, heating of the hot water flowing in from the water-refrigerant heat exchanger 12 by the electric heater 13 is stopped.

[0056] In this manner, the air conditioning control device 15 repeatedly executes the water temperature detection process in step S100, the water temperature determination process in step S110, the electric heater ON process in step S120, and the electric heater OFF process in step S130.

[0057] As a result, the air conditioning control device 15 controls the electric heater 13 by adjusting the amount of heat dissipated from the electric heater 13 to the hot water so that the temperature of the hot water in the heater 10 approaches the target temperature (e.g., 60°C). As a result, the heater 10 can bring the air temperature in the vehicle interior 30 closer to the target temperature by using the hot water.

[0058] In the refrigeration cycle device 3 for refrigeration, the compressor 20 draws in refrigerant from the evaporator 23 through the suction port 20a, compresses it, and discharges the high-pressure refrigerant from the discharge port 20b. The water-refrigerant heat exchanger 12 heats the hot water flowing in from the heater 10 by the latent heat of condensation and the sensible heat of the high-pressure refrigerant discharged from the compressor 20.

[0059] Next, in the condenser 21, the high-pressure refrigerant flowing in from the water-refrigerant heat exchanger 12 dissipates heat to the outside air blown by the electric fan 21a. The pressure reducing valve 22 reduces the pressure of the refrigerant that has passed through the condenser 21. The evaporator 23 draws the low-pressure refrigerant that has passed through the pressure reducing valve 22 from the air inside the freezer 40.

[0060] As a result, the refrigerant circulates in the order of the evaporator 23, the compressor 20, the water-refrigerant heat exchanger 12, the condenser 21, the pressure reducing valve 22, and the evaporator 23. As a result, the evaporator 23 cools the inside of the freezer 40 with the low-pressure refrigerant.

[0061] The refrigeration control device 24 controls the compressor 20 or the electric fan 21a. For example, when the compressor 20 is controlled by the refrigeration control device 24 and the pressure of the refrigerant discharged from the compressor 20 increases, the pressure of the high-pressure refrigerant flowing into the water-refrigerant heat exchanger 12 increases. As a result, the temperature of the high-pressure refrigerant flowing into the water-refrigerant heat exchanger 12 increases.

[0062] On the other hand, when the compressor 20 is controlled by the refrigeration control device 24 and the pressure of the refrigerant discharged from the compressor 20 decreases, the pressure of the high-pressure refrigerant in the water-refrigerant heat exchanger 12 decreases. As a result, the condensation temperature of the high-pressure refrigerant in the water-refrigerant heat exchanger 12 decreases.

[0063] In addition, when the electric fan 21a is controlled by the refrigeration control device 24 to increase the amount of air passing through the condenser 21, the amount of heat dissipated from the condenser 21 to the outside air increases. This causes the pressure of the high-pressure refrigerant in the water-refrigerant heat exchanger 12 to decrease. This causes the temperature of the high-pressure refrigerant in the water-refrigerant heat exchanger 12 to decrease.

[0064] On the other hand, when the electric fan 21a is controlled by the refrigeration control device 24 to reduce the amount of air passing through the condenser 21, the amount of heat dissipated from the condenser 21 to the outside air decreases. This causes the pressure of the high-pressure refrigerant in the water-refrigerant heat exchanger 12 to increase. This causes the temperature of the high-pressure refrigerant in the water-refrigerant heat exchanger 12 to increase.

[0065] The refrigeration control device 24 controls the compressor 20 or the electric fan 21a to bring the refrigerant temperature during condensation in the water-refrigerant heat exchanger 12 closer to a target temperature. In this embodiment, the target temperature is a temperature (e.g., 60°C) higher than the temperature (e.g., 50°C) of the hot water flowing from the heater 10 to the water-refrigerant heat exchanger 12. This allows the water-refrigerant heat exchanger 12 to appropriately heat the hot water flowing out from the pump 11 by the latent heat of condensation and sensible heat of the high-pressure refrigerant discharged from the compressor 20.

[0066] The Mollier diagram Mo of such a refrigeration cycle device 3 for refrigeration is shown in Fig. 3. The Mollier diagram Mo shows the compression process, condensation process, decompression process, and evaporation process of the vapor compression refrigeration cycle. In Fig. 3, the horizontal axis represents the enthalpy of the refrigerant, and the vertical axis represents the refrigerant pressure.

[0067] Specifically, the Mollier diagram Mo is a diagram including points A, B, C, and D. The section from point A to point B is a compression process in which the refrigerant is compressed by the compressor 20. The section from point B to point C is a condensation process in which the refrigerant releases heat and is condensed by the water-refrigerant heat exchanger 12 and the condenser 21. The water-refrigerant heat exchanger 12 of this embodiment heats the hot water by the latent heat of condensation and sensible heat in the condensation process.

[0068] The section from point C to point D is a decompression process in which the refrigerant is decompressed by pressure reducing valve 22. The section from point D to point A is an evaporation process in which the refrigerant is evaporated by evaporator 23. The refrigerant pressure in the condensation process is lower than the critical point K. Points A and B each have a larger enthalpy than the refrigerant saturated vapor line S1. Point C has a smaller enthalpy than the refrigerant saturated liquid line S2. Point D has a larger enthalpy than the refrigerant saturated liquid line S2 and a smaller enthalpy than the refrigerant saturated vapor line S1.

[0069] In this embodiment, a refrigerant is used that has a refrigerant saturated vapor pressure of 2 MPa or more in absolute pressure when the high-pressure refrigerant is condensed at a refrigerant temperature of 60° C. In FIG. 3, the line connecting points B and C is line BC, and the point where line BC intersects with the refrigerant saturated vapor line S1 is point Hg. A refrigerant is used that has a refrigerant saturated vapor pressure of 2 MPa or more in absolute pressure when the refrigerant temperature is 60° C. at point Hg.

[0070] For example, as shown in Fig. 4, refrigeration refrigerants such as R404A and R452A are used as the refrigerant. As can be seen from Fig. 4, R404A and R452A are refrigerants whose refrigerant saturated vapor pressure is 2 MPa or more in absolute pressure when the refrigerant temperature is 60°C.

[0071] In addition, the refrigerant saturated vapor pressures of R404A and R452A when the refrigerant temperature in Figure 4 is 40°C are refrigerant saturated vapor pressures when R404A and R452A are used as refrigerants in a refrigeration cycle device that does not use a water-refrigerant heat exchanger 12.

[0072] The refrigerant saturated vapor pressures of R134a and R1234yf when the refrigerant temperatures in FIG. 4 are 60° C. and 40° C. are the refrigerant saturated vapor pressures when R134a and R1234yf are used as air-conditioning refrigerants in an air-conditioning refrigeration cycle device.

[0073] According to the present embodiment described above, the heat exchange system 1 includes a refrigeration cycle device 3 that configures a vapor compression refrigeration cycle. The refrigeration cycle device 3 includes a compressor 20 that draws in a refrigerant from an intake port 20a, compresses it, and discharges it from a discharge port 20b. The refrigeration cycle device 3 includes a water-refrigerant heat exchanger 12 that heats the hot water by the latent heat of condensation and sensible heat of the refrigerant when the refrigerant discharged from the discharge port 20b of the compressor 20 releases heat to the hot water from the pump 11 and condenses.

[0074] In the refrigeration cycle device 3, the refrigerant that has passed through the water-refrigerant heat exchanger 12 is guided through a pressure reducing valve 22 and an evaporator 23 to an intake port 20a of a compressor 20 to circulate the refrigerant. In the vapor compression refrigeration cycle, a refrigerant is used that has a refrigerant saturated vapor pressure of 2 MPa or more in absolute pressure when the refrigerant temperature is 60°C when the refrigerant is condensed.

[0075] The heat exchange system 1 includes a hot water circuit 2 having an electric heater 13 that heats hot water that has absorbed heat from the refrigerant in a water-refrigerant heat exchanger 12, and a heating heater 10 that dissipates heat from the hot water heated by the electric heater 13 to the vehicle interior 30.

[0076] The flow path through which hot water flows from the hot water outlet 10b of the heating heater 10 to the hot water inlet 12a of the water-refrigerant heat exchanger 12 is designated as hot water flow path 16a, and the flow path through which hot water flows from the hot water outlet 12b of the water-refrigerant heat exchanger 12 to the hot water inlet 10a of the heating heater 10 is designated as hot water flow path 17a.

[0077] The electric heater 13 is disposed only in the hot water flow path 17a out of the hot water flow path 16a and the hot water flow path 17a.

[0078] In the hot water circuit 2, hot water flows through the electric heater 13, the heater 10, the water-refrigerant heat exchanger 12, and the electric heater 13 in this order, so that the hot water circulates through the hot water flow paths 16a and 17a.

[0079] Generally, refrigeration refrigerants have a higher refrigerant saturated vapor pressure when condensing than air-conditioning refrigerants, as shown in Figure 4. Figure 4 shows the refrigerant saturated vapor pressure when refrigerant temperatures are 60°C and 40°C when refrigerant for refrigeration and air-conditioning are condensed, respectively.

[0080] In this embodiment, the water-refrigerant heat exchanger 12 that heats hot water by the latent heat of condensation and the sensible heat of the refrigerant is used as a condenser in the refrigeration cycle apparatus 3. When the water-refrigerant heat exchanger 12 is used to heat hot water in the refrigeration cycle apparatus 3, the condensation pressure of the refrigerant needs to be higher than when the water-refrigerant heat exchanger 12 is not used.

[0081] Here, in order to efficiently heat the hot water, it is desirable to heat the hot water only with the heat radiated from the refrigerant by the water-refrigerant heat exchanger 12 without using the electric heater 13 .

[0082] However, in the refrigeration cycle device 3 for refrigeration, in order to bring the hot water temperature closer to the target temperature using only the water-refrigerant heat exchanger 12 without using the electric heater 13, the refrigerant pressure during condensation of the refrigerant needs to be higher than when the water-refrigerant heat exchanger 12 is not used.

[0083] In this case, if the pressure of the high-pressure refrigerant rises due to a disturbance or the like and exceeds the upper limit, it is necessary to implement pressure protection control to lower the high-pressure refrigerant by controlling the compressor 20, the electric fan 53a, etc. As a result, it may be impossible to sufficiently increase the condensation temperature of the refrigerant in the water-refrigerant heat exchanger 12, and it may not be possible to increase the hot water temperature to the required target temperature.

[0084] On the other hand, if the power consumption of the compressor 20 is limited due to the remaining charge of the vehicle battery, the pressure of the high-pressure refrigerant discharged from the compressor 20 cannot be sufficiently increased. As a result, the condensation temperature of the refrigerant in the water-refrigerant heat exchanger 12 cannot be sufficiently increased, and the hot water temperature cannot be increased to the required target temperature.

[0085] In contrast, in this embodiment, in addition to the water-refrigerant heat exchanger 12, the electric heater 13 is used. Furthermore, in the hot water circuit 2, as described above, hot water flows through the electric heater 13, the heater 10, the water-refrigerant heat exchanger 12, and the electric heater 13 in this order, so that the hot water circulates through the hot water flow paths 16a and 17a.

[0086] Therefore, the temperature of the refrigerant flowing from the compressor 20 into the water-refrigerant heat exchanger 12 is higher than the temperature of the hot water flowing from the heater 10 into the water-refrigerant heat exchanger 12. This allows the water-refrigerant heat exchanger 12 to heat the hot water that has dissipated heat in the heater 10 before the electric heater 13.

[0087] Therefore, even if the condensation temperature of the refrigerant in the water-refrigerant heat exchanger 12 cannot be made sufficiently high due to the above-mentioned pressure protection control of the high-pressure refrigerant or limitations on the power consumption of the compressor 20, the hot water temperature in the heater 10 can be raised to the target temperature as described below.

[0088] That is, the hot water dissipated by the heater 10 can be heated to a temperature halfway to the target temperature by the water-refrigerant heat exchanger 12, and then the heated hot water can be heated to the target temperature by the electric heater 13.

[0089] On the other hand, when the electric heater 13 heats the hot water prior to the water-refrigerant heat exchanger 12, it is possible that the temperature of the hot water flowing from the electric heater 13 to the water-refrigerant heat exchanger 12 will be higher than the temperature of the refrigerant flowing from the compressor 20 to the water-refrigerant heat exchanger 12.

[0090] In this case, heat cannot be transferred from the refrigerant to the hot water in the water-refrigerant heat exchanger 12. In contrast, in this embodiment, as described above, the water-refrigerant heat exchanger 12 heats the hot water that has dissipated heat in the heater 10 before it is heated by the electric heater 13. Therefore, it is possible to provide a heat exchange system 1 that efficiently transfers the latent heat of condensation of the refrigerant in the water-refrigerant heat exchanger 12 to the hot water.

[0091] The present embodiment configured as described above can provide the following advantageous effects. That is, the heat exchange system 1 of the present embodiment is applied to a refrigerated vehicle equipped with a freezer 40. The refrigeration cycle device 3 for refrigeration includes a pressure reducing valve 22 that reduces the pressure of the refrigerant discharged from the compressor 20, and an evaporator 23 in which the refrigerant reduced in pressure by the pressure reducing valve 22 absorbs heat from the inside of the freezer 40 and evaporates the refrigerant.

[0092] As described above, the water-refrigerant heat exchanger 12 heats the hot water by utilizing heat absorbed from inside the freezer 40. Therefore, the hot water can be heated efficiently without wasting the heat of the refrigerant.

[0093] Second embodiment In the present second embodiment, a heat exchange system 1 in which a refrigeration cycle 4 for air conditioning is added to the components in the first embodiment will be described with reference to FIG.

[0094] Fig. 5 is a diagram showing a detailed configuration of the heat exchange system 1 of this embodiment. The heat exchange system 1 of this embodiment is obtained by adding a refrigeration cycle 4 for air conditioning to the heat exchange system 1 of the first embodiment. In Fig. 5, the same reference numerals as those in Fig. 1 indicate the same things, and the description thereof will be omitted.

[0095] Hereinafter, the refrigeration cycle 4 for air conditioning, which is a difference between this embodiment and the above-mentioned first embodiment, will be described with reference to FIG.

[0096] The air-conditioning refrigeration cycle 4 includes a compressor 50, a water-refrigerant heat exchanger 51, a pressure reducing valve 52, an exterior heat exchanger 53, an electric fan 53a, a pressure reducing valve 54, an evaporator 55, an electric fan 55a, a bypass passage 56, an on-off valve 57, and a gas-liquid separator 58.

[0097] The compressor 50 draws in a refrigerant from an intake port 50a by driving the compression mechanism, compresses it, and discharges it from a discharge port 50b. The compressor 50, together with a pressure reducing valve 52, a water-refrigerant heat exchanger 51, an exterior heat exchanger 53, a pressure reducing valve 54, an evaporator 55, a bypass passage 56, and a gas-liquid separator 58, constitute a vapor compression refrigeration cycle that circulates the refrigerant.

[0098] In this embodiment, an electric compressor in which a compression mechanism for compressing a refrigerant is driven by an electric motor is used as the compressor 50. The electric motor of the compressor 50 is driven by electric power supplied from an on-board battery.

[0099] The water-refrigerant heat exchanger 51 and the electric heater 13 are arranged in series between the hot water outlet 12b of the water-refrigerant heat exchanger 12 and the hot water inlet 10a of the heater 10. The water-refrigerant heat exchanger 51 is a second heater device arranged upstream of the electric heater 13 in the hot water flow direction.

[0100] The water-refrigerant heat exchanger 51 is a heat exchanger that exchanges heat between the high-pressure refrigerant discharged from the compressor 50 and the hot water flowing in from the water-refrigerant heat exchanger 12. The water-refrigerant heat exchanger 51 dissipates heat from the high-pressure refrigerant discharged from the compressor 50 to the hot water and condenses it. The water-refrigerant heat exchanger 51 heats the hot water flowing in from the water-refrigerant heat exchanger 12 with the latent heat of condensation and sensible heat of the high-pressure refrigerant discharged from the compressor 50.

[0101] In this embodiment, the heating COP of the water-refrigerant heat exchanger 51 is higher than the heating COP of the electric heater 13.

[0102] In other words, the water-refrigerant heat exchanger 51 and the electric heater 13 are arranged so that the heating COP becomes lower as the hot water outlet 51b of the water-refrigerant heat exchanger 51 approaches the hot water inlet 10a of the heater 10. In other words, the water-refrigerant heat exchanger 51 and the electric heater 13 are arranged so that the heating COP becomes higher as the hot water inlet 10a of the heater 10 approaches the hot water outlet 12b of the water-refrigerant heat exchanger 51.

[0103] The heating COP is an index that indicates the energy consumption efficiency during heating. COP is an abbreviation of Coefficient Of Performance. Specifically, the heating COP is expressed by the following formula 1.

[0104] Heating COP = heating capacity (kW) ÷ heating power consumption (kW) (Formula 1) Here, the heating capacity of the water-refrigerant heat exchanger 51 and the power consumption of the refrigeration cycle device 3 for refrigeration as heating power consumption are substituted into Equation 1 to determine the heating COP of the water-refrigerant heat exchanger 51.

[0105] The heating capacity of the electric heater 13 and the power consumption of the electric heater 13 as heating power consumption are substituted into Equation 1, whereby the heating COP of the electric heater 13 is obtained.

[0106] On the other hand, the pressure reducing valve 52 is disposed between the hot water outlet 51b of the water-refrigerant heat exchanger 51 and the hot water inlet 53c of the exterior heat exchanger 53. The pressure reducing valve 52 adjusts the flow path cross-sectional area of ​​the refrigerant flow path 59 between the hot water outlet 51b of the water-refrigerant heat exchanger 51 and the hot water inlet 53c of the exterior heat exchanger 53. Specifically, the pressure reducing valve 52 includes a valve mechanism 52c and an electric actuator 52d.

[0107] The valve mechanism 52c adjusts the flow path cross-sectional area of ​​the refrigerant flow path 59. The electric actuator 52d drives the valve mechanism 52c. Thus, the electric actuator 52d drives the valve mechanism 52c, thereby adjusting the flow path cross-sectional area of ​​the refrigerant flow path 59.

[0108] The exterior heat exchanger 53 is disposed outside the freezer 40 and outside the vehicle interior 30. The exterior heat exchanger 53 exchanges heat between the refrigerant flowing in from the water-refrigerant heat exchanger 51 and outside air passing through the exterior heat exchanger 53 itself.

[0109] The electric fan 53a is disposed outside the freezer 40 and outside the vehicle compartment 30. The electric fan 53a generates a flow of outside air passing through the vehicle exterior heat exchanger 53 by rotating its impeller by an electric motor. The electric motor of the electric fan 53a is driven by power supplied from the vehicle battery.

[0110] Here, a refrigerant flow path through which the refrigerant flows from the refrigerant outlet 53b of the exterior heat exchanger 53 to the refrigerant inlet 55b of the evaporator 55 is referred to as a refrigerant flow path 62.

[0111] The pressure reducing valve 54 includes a valve mechanism 54a that adjusts the flow path cross-sectional area of ​​the refrigerant flow path 62, and an electric actuator 54b that drives the valve mechanism 54a.

[0112] The evaporator 55 is a heat exchanger that exchanges heat between the low-pressure refrigerant reduced in pressure by the pressure reducing valve 54 and the inside air passing through the evaporator 55. The evaporator 55 is disposed inside the passenger compartment 30.

[0113] In the evaporator 55, the low-pressure refrigerant decompressed by the pressure reducing valve 54 absorbs heat from the inside air passing through the evaporator 55 itself. Thus, the inside air is cooled by the heat absorption by the refrigerant. The electric fan 55a is disposed inside the passenger compartment 30. The electric fan 55a generates a flow of inside air passing through the evaporator 55 itself.

[0114] Here, a branching portion in the refrigerant flow path between refrigerant outlet 53b of exterior heat exchanger 53 and refrigerant inlet 54c of pressure reducing valve 54 is referred to as branching portion 60. A branching portion in the refrigerant flow path between refrigerant outlet 55c of evaporator 55 and refrigerant inlet 58a of gas-liquid separator 58 is referred to as branching portion 61. Hereinafter, branching portion 60 and branching portion 61 are also referred to as branching portions 60 and 61.

[0115] The bypass passage 56 is a refrigerant passage that allows the refrigerant to flow from the refrigerant outlet 53 b of the exterior heat exchanger 53 through branching portions 60 and 61 to the refrigerant inlet 58 a of the gas-liquid separator 58 , bypassing the pressure reducing valve 54 and the evaporator 55 .

[0116] The on-off valve 57 opens and closes the bypass flow passage 56. Specifically, the on-off valve 57 includes a valve mechanism 57a that opens and closes the bypass flow passage 56, and an electric actuator 57b that drives the valve mechanism 57a. The gas-liquid separator 58 stores the liquid-phase refrigerant out of the gas-phase refrigerant and the liquid-phase refrigerant that have passed through either the bypass flow passage 56 or the evaporator 55, and guides the gas-phase refrigerant to the suction port 50a of the compressor 50.

[0117] The air conditioning control device 15 of this embodiment controls the electric heater 13 in the same manner as in the first embodiment. In addition, the air conditioning control device 15 performs cooling operation and heating operation by controlling the pressure reducing valves 52, 54, the on-off valve 57, and the electric fans 53a, 55a, as described below. As the air conditioning refrigerant in this embodiment, for example, R134a or R1234yf is used.

[0118] Next, specific examples of the heating operation and the cooling operation in the heat exchange system 1 of this embodiment will be described. Below, the heating operation will be described before the cooling operation.

[0119] (Heating operation) First, in the hot water circuit 2, the pump 11, like the first embodiment, draws in hot water from the hot water outlet 10b of the heater 10 and discharges the drawn hot water toward the hot water inlet 12a of the water-refrigerant heat exchanger 12. As a result, the hot water flows through the heater 10, the pump 11, the water-refrigerant heat exchanger 12, the water-refrigerant heat exchanger 51, the electric heater 13, and the heater 10 in this order.

[0120] In the refrigeration cycle device 3 for refrigeration, the compressor 20, the water-refrigerant heat exchanger 12, the condenser 21, the pressure reducing valve 22, the evaporator 23, and the electric fans 21a and 23a are operated in the same manner as in the first embodiment. As a result, the water-refrigerant heat exchanger 12 transfers heat from the high-pressure refrigerant discharged from the compressor 20 to the hot water flowing in from the pump 11, and condenses it, in the same manner as in the first embodiment. The water-refrigerant heat exchanger 12 heats the hot water flowing in from the pump 11 by using the latent heat of condensation and the sensible heat of the high-pressure refrigerant discharged from the compressor 20 .

[0121] Meanwhile, the air conditioning control device 15 controls the valve mechanism 52c of the pressure reducing valve 52 via the electric actuator 52d to adjust the flow path cross-sectional area of ​​the refrigerant flow path 59. The air conditioning control device 15 closes the refrigerant flow path 62 by controlling the valve mechanism 54a of the pressure reducing valve 54 via the electric actuator 54b.

[0122] The air conditioning control device 15 controls the valve mechanism 57a of the on-off valve 57 via the electric actuator 57b to open the bypass passage 56. The air conditioning control device 15 drives the electric fan 53a to generate a flow of outside air passing through the exterior heat exchanger 53.

[0123] At this time, the compressor 50 draws in the refrigerant from the suction port 50a, compresses it, and discharges it from the discharge port 50b. Then, the water-refrigerant heat exchanger 51 condenses the high-pressure refrigerant discharged from the compressor 50 by dissipating heat to the hot water flowing in from the water-refrigerant heat exchanger 12. At this time, the water-refrigerant heat exchanger 51 heats the hot water flowing in from the water-refrigerant heat exchanger 12 by the latent heat of condensation and sensible heat of the high-pressure refrigerant.

[0124] The pressure reducing valve 52 reduces the pressure of the refrigerant condensed by the water-refrigerant heat exchanger 51. The refrigerant reduced in pressure by the pressure reducing valve 52 absorbs heat from the outside air in the exterior heat exchanger 53 and becomes a two-phase gas-liquid state. Therefore, the refrigerant flows in a mixed state of the gas-phase refrigerant and the liquid-phase refrigerant from the exterior heat exchanger 53 through the bypass passage 56 to the gas-liquid separator 58.

[0125] Thereafter, in the gas-liquid separator 58, the liquid phase refrigerant is stored, and the gas phase refrigerant is guided to the suction port 50a of the compressor 50. As a result, during heating operation, the refrigerant flows through the compressor 50 in the order of the water-refrigerant heat exchanger 51, the pressure reducing valve 52, the exterior heat exchanger 53, the bypass flow path 56, the gas-liquid separator 58, and the compressor 50.

[0126] Therefore, heat absorbed from the outside air by the exterior heat exchanger 53 is transferred to the hot water in the water-refrigerant heat exchanger 51. In this manner, the hot water heated by the water-refrigerant heat exchanger 12 and the water-refrigerant heat exchanger 51 flows toward the hot water inlet 10a of the heater 10. At this time, the air conditioning control device 15 executes the water temperature control process in the same manner as in the first embodiment.

[0127] As a result, the air conditioning control device 15 controls the electric heater 13 to adjust the amount of heat released from the electric heater 13 to the hot water. Therefore, the air conditioning control device 15 controls the electric heater 13 so that the temperature of the hot water in the heater 10 approaches a target temperature (e.g., 60°C). Therefore, the electric heater 13 heats the hot water heated by the water-refrigerant heat exchanger 51 with power supplied from the vehicle battery.

[0128] At this time, the hot water heated by the electric heater 13 flows to the heater 10. The heater 10 dissipates heat from the hot water heated by the electric heater 13 to the inside air. In this way, the heater 10 can bring the air temperature of the vehicle interior 30 closer to the target temperature by the hot water.

[0129] (Cooling operation) In the hot water circuit 2, the air conditioning control device 15 stops the pump 11 and the electric heater 13. As a result, the water in the hot water circuit 2 is not heated by the electric heater 13. With the pump 11 stopped, the circulation of hot water in the hot water circuit 2 is also not generated.

[0130] On the other hand, in the refrigeration cycle device 3 for refrigeration, the compressor 20 draws in refrigerant from the evaporator 23 through the suction port 20a, compresses it, and discharges the high-pressure refrigerant from the discharge port 20b. The discharged high-pressure refrigerant passes through the water-refrigerant heat exchanger 12 and flows to the condenser 21. At this time, in the water-refrigerant heat exchanger 12, the high-pressure refrigerant does not release heat to the hot water.

[0131] On the other hand, the condenser 21 dissipates heat from the high-pressure refrigerant flowing in from the water-refrigerant heat exchanger 12 to the outside air. The pressure reducing valve 22 reduces the pressure of the refrigerant that has passed through the condenser 21. The evaporator 23 draws the low-pressure refrigerant that has passed through the pressure reducing valve 22 from the air inside the freezer 40.

[0132] As a result, the refrigerant circulates in the order of the evaporator 23, the compressor 20, the water-refrigerant heat exchanger 12, the condenser 21, the pressure reducing valve 22, and the evaporator 23. Therefore, the condenser 21 dissipates heat absorbed from the inside of the freezer 40 by the evaporator 23 to the outside air. Therefore, the evaporator 23 can cool the inside of the freezer 40.

[0133] Meanwhile, the air conditioning control device 15 controls the valve mechanism 52c of the pressure reducing valve 52 via the electric actuator 52d to maximize the flow path cross-sectional area of ​​the refrigerant flow path 59. The air conditioning control device 15 adjusts the flow path cross-sectional area of ​​the refrigerant flow path 62 by controlling the valve mechanism 54a of the pressure reducing valve 54 via the electric actuator 54b.

[0134] The air conditioning control device 15 closes the bypass passage 56 by controlling the valve mechanism 57a of the opening / closing valve 57 via the electric actuator 57b. The air conditioning control device 15 drives the electric fan 53a to generate a flow of outside air passing through the exterior heat exchanger 53. The air conditioning control device 15 drives the electric fan 55a to generate a flow of inside air passing through the evaporator 55.

[0135] At this time, the compressor 50 draws in the refrigerant from the suction port 50a, compresses it, and discharges the high-pressure refrigerant from the discharge port 50b. Then, the high-pressure refrigerant passes through the water-refrigerant heat exchanger 51 and the pressure reducing valve 52 and flows into the exterior heat exchanger 53. At this time, the high-pressure refrigerant does not release heat in the water-refrigerant heat exchanger 51. The pressure reducing valve 52 does not reduce the pressure of the high-pressure refrigerant.

[0136] On the other hand, the exterior heat exchanger 53 condenses the high-pressure refrigerant by dissipating heat from the high-pressure refrigerant that has passed through the pressure reducing valve 52 to the outside air.

[0137] Thereafter, the pressure reducing valve 54 reduces the pressure of the refrigerant that has passed through the exterior heat exchanger 53. The refrigerant reduced in pressure by the pressure reducing valve 54 absorbs heat from the interior air and becomes a two-phase gas-liquid refrigerant in the evaporator 55. Therefore, the refrigerant flows from the evaporator 55 to the gas-liquid separator 58 in a mixed state of gas-phase refrigerant and liquid-phase refrigerant.

[0138] Thereafter, in the gas-liquid separator 58, of the gas-phase refrigerant and the liquid-phase refrigerant, the liquid-phase refrigerant is stored, while the gas-phase refrigerant is guided to the suction port 50a of the compressor 50. As a result, during cooling operation, the refrigerant flows through the compressor 50 in the order of the water-refrigerant heat exchanger 51, the pressure reducing valve 52, the exterior heat exchanger 53, the pressure reducing valve 54, the evaporator 55, the gas-liquid separator 58, and the compressor 50.

[0139] Therefore, the heat absorbed from the inside air in the evaporator 55 is discharged to the outside air in the exterior heat exchanger 53 .

[0140] In this case, the water-refrigerant heat exchanger 12, the water-refrigerant heat exchanger 51, and the electric heater 13 do not heat the water in the hot water circuit 2. Therefore, the room heater 10 does not radiate heat to the inside air.

[0141] According to the present embodiment described above, in the hot water circuit 2 of the heat exchange system 1, the water-refrigerant heat exchanger 51 and the electric heater 13 are arranged in series.

[0142] The heating COP of the water-refrigerant heat exchanger 51 and the electric heater 13 decreases from the hot water outlet 12b of the water-refrigerant heat exchanger 12 to the hot water inlet 10a of the heater 10. That is, the electric heater 13 has the lowest heating COP among the water-refrigerant heat exchanger 51 and the electric heater 13.

[0143] The heat exchange system 1 includes an air conditioning control device 15 that controls the electric heater 13 to adjust the amount of heat radiated from the electric heater 13 to the hot water in the hot water circuit 2, and a temperature sensor 14 that detects the temperature of the hot water flowing from the electric heater to the hot water inlet 10a of the heating heater 10.

[0144] With the water-refrigerant heat exchangers 12, 51 heating the hot water, the air conditioning control device 15 controls the amount of heat radiated from the electric heater 13 to the hot water based on the temperature detected by the temperature sensor 14. In this way, the air conditioning control device 15 controls the electric heater 13 based on the temperature detected by the temperature sensor 14 so as to bring the hot water temperature closer to the target temperature.

[0145] Therefore, the hot water is heated to a halfway point of the target temperature by the water-refrigerant heat exchangers 12 and 51, and then This heated water can be heated to a target temperature by the electric heater 13. This allows the electric heater 13 and the water-refrigerant heat exchangers 12, 51 to efficiently heat the water.

[0146] Third embodiment In this third embodiment, the manufacturing process of the heat exchange system 1 of the refrigerated vehicle of the first embodiment will be described with reference to Fig. 6, Fig. 7, Fig. 8, and Fig. 9. Fig. 6 is a flow chart showing the manufacturing process of the heat exchange system 1 in the refrigerated vehicle of this embodiment. Fig. 7 shows the hot water circuit 2 installed in the refrigerated vehicle in the manufacturing process of the refrigerated vehicle by an automobile manufacturer of this embodiment.

[0147] First, in the manufacturing process of the refrigerated vehicle by the automobile manufacturer in step S200 of Fig. 6, only the hot water circuit 2 of the heat exchange system 1 is installed in the refrigerated vehicle. The freezer 40 and the refrigeration cycle device 3 for refrigeration are not installed in this refrigerated vehicle. Therefore, in the manufacturing process of the refrigerated vehicle by the automobile manufacturer, when the hot water circuit 2 is installed in the refrigerated vehicle, the water-refrigerant heat exchanger 12 is not connected to the hot water circuit 2.

[0148] As shown in FIG. 7, in the hot water circuit 2, a hot water outlet 11b of the pump 11 is connected to a hot water pipe (i.e., a first heat medium pipe) 80 that guides the hot water discharged from the pump 11 to the hot water inlet 13a side of the electric heater 13.

[0149] To the hot water inlet 13a of the electric heater 13, a hot water pipe (that is, a second heat medium pipe) 81 that guides the hot water flowing out from the hot water outlet 80a of the hot water pipe 80 to the hot water inlet 13a of the electric heater 13 is connected.

[0150] Here, a hot water outlet (ie, heat medium outlet) 80a of the hot water pipe 80 and a hot water inlet (ie, heat medium inlet) 81a of the hot water pipe 81 are connected by a connecting hose 70 instead of the water-refrigerant heat exchanger 12.

[0151] 8, the hot water outlet 80a of the hot water piping 80 is inserted into one opening of the connecting hose 70. At this time, the connecting hose 70 elastically deforms, and the outer periphery of the hot water piping 80 on the hot water outlet 80a side is in close contact with the inner periphery of the connecting hose 70.

[0152] The hot water inlet 81a of the hot water pipe 81 is inserted into the other side opening of the connecting hose 70. At this time, the connecting hose 70 elastically deforms, and the outer periphery of the hot water pipe 81 on the hot water inlet 81a side is in close contact with the inner periphery of the connecting hose 70.

[0153] As a result, the hot water outlet 80a of the hot water pipe 80 and the hot water inlet 81a of the hot water pipe 81 are configured to be detachable by the connecting hose 70. As shown in Fig. 8, the connecting hose 70 is formed in a short cylindrical shape. The connecting hose 70 is formed from, for example, a resin material such as rubber. The hot water pipe 80 and the hot water pipe 81 are formed from, for example, a metal material such as aluminum.

[0154] The refrigerated vehicle equipped with the hot water circuit 2 in which the hot water pipes 80, 81 are connected by the connecting hose 70 in this manner is transported to a refrigerated vehicle manufacturer. At this time, in the manufacturing process of the refrigerated vehicle at the refrigerated vehicle manufacturer in step S210 of FIG. 6, the freezer 40 and the refrigeration cycle device 3 for refrigeration are installed in the refrigerated vehicle.

[0155] The water-refrigerant heat exchanger 12 is disposed between the hot water outlet 80a of the hot water pipe 80 and the hot water inlet 81a of the hot water pipe 81 by removing the connecting hose 70. At this time, the hot water circuit 2 and the refrigeration cycle device 3 for refrigeration are connected as follows.

[0156] That is, the connecting hose 70 is removed from the hot water outlet 80a of the hot water pipe 80 and the hot water inlet 81a of the hot water pipe 81. As shown in Fig. 9, the hot water outlet 80a of the hot water pipe 80 is connected to the hot water inlet 12a of the water-refrigerant heat exchanger 12. The hot water inlet 81a of the hot water pipe 81 is connected to the hot water outlet 12b of the water-refrigerant heat exchanger 12.

[0157] As described above, the water-refrigerant heat exchanger 12 is disposed between the hot water outlet 80a of the hot water pipe 80 and the hot water inlet 81a of the hot water pipe 81, instead of the connecting hose 70. When the water-refrigerant heat exchanger 12 is disposed between the hot water outlet 80a of the hot water pipe 80 and the hot water inlet 81a of the hot water pipe 81, the hot water circuit 2 and the refrigeration cycle device 3 for refrigeration are connected via the water-refrigerant heat exchanger 12, similarly to the first embodiment.

[0158] This causes the hot water circuit 2 and the refrigeration cycle device 3 to operate in the same manner as in the first embodiment. That is, the water-refrigerant heat exchanger 12 heats the hot water in the hot water circuit 2 by the latent heat of condensation and sensible heat of the refrigerant when the high-pressure refrigerant discharged from the compressor 20, which draws in, compresses, and discharges the refrigerant, is condensed.

[0159] The water-refrigerant heat exchanger 12, together with the compressor 20, the pressure reducing valve 22, and the evaporator 23, constitute a vapor compression refrigeration cycle for refrigeration that circulates the refrigerant. This vapor compression refrigeration cycle for refrigeration uses a refrigerant whose refrigerant saturation pressure is 2 MPa or more in absolute pressure when the refrigerant temperature is 60° C. when the refrigerant is condensed. The electric heater 13 is arranged only in the hot water flow path 17a out of the hot water flow path 16a and the hot water flow path 17a.

[0160] In the hot water circuit 2, hot water flows through the electric heater 13, the heater 10, the water-refrigerant heat exchanger 12, and the electric heater 13 in this order, so that the hot water circulates through the hot water flow path 16a and the hot water flow path 17a.

[0161] According to the present embodiment described above, the hot water circuit 2 installed in a refrigerated vehicle by an automobile manufacturer includes an electric heater 13 that heats hot water, and a heating heater 10 that radiates heat from the hot water heated by the electric heater 13 to the vehicle interior 30.

[0162] The hot water circuit 2 includes a hot water pipe 80 that guides the hot water discharged from the hot water outlet 10b of the heater 10 to the hot water inlet 13a of the electric heater 13, and a hot water pipe 81 that guides the hot water that has passed through the hot water pipe 80 to the hot water inlet 13a of the electric heater 13. In addition, the hot water circuit 2 includes a connection hose 70 that connects the hot water outlet 80a of the hot water pipe 80 and the hot water inlet 81a of the hot water pipe 81.

[0163] As a result, in the hot water circuit 2, the hot water outlet 80a of the hot water pipe 80 and the hot water inlet 81a of the hot water pipe 81 are configured to be detachable by the connecting hose . In addition, in a refrigerated vehicle manufacturer, the water-refrigerant heat exchanger 12 is disposed between the hot water outlet 80a of the hot water pipe 80 and the hot water inlet 81a of the hot water pipe 81 in the hot water circuit 2 by removing the connecting hose 70.

[0164] As a result, in the refrigerated vehicle manufacturer, a water-refrigerant heat exchanger 12 is disposed between the hot water outlet 80a of the hot water pipe 80 and the hot water inlet 81a of the hot water pipe 81 in the hot water circuit 2, instead of the connecting hose 70.

[0165] Therefore, a refrigerated vehicle manufacturer can easily place the water-refrigerant heat exchanger 12 in the correct location in the hot water circuit 2. This can prevent the hot water circuit 2 and the refrigeration cycle device 3 for refrigeration from being connected in an incorrect structure.

[0166] (Other embodiments)

[0167] (1) In the above first, second and third embodiments, examples have been described in which a refrigeration refrigerant such as R404A or R452A is used as a refrigerant in the refrigeration cycle device 3 for refrigeration, the refrigerant temperature of which is 60°C and the saturated vapor pressure of which is 2 MPa or more in absolute pressure when the high-pressure refrigerant is condensed.

[0168] However, in the refrigeration cycle device 3 for refrigeration, refrigerants other than R404A and R452A may be used as long as the refrigerant temperature is 60° C. and the refrigerant saturated vapor pressure is 2 MPa or more in absolute pressure when the high-pressure refrigerant is condensed.

[0169] (2) In the above first, second, and third embodiments, an example in which the heat exchange system 1 of the present disclosure is applied to an electric refrigeration vehicle has been described. However, instead of this, the heat exchange system 1 of the present disclosure may be applied to a stationary refrigeration device.

[0170] (3) In the above first, second and third embodiments, an example has been described in which the pump 11 is disposed in the hot water circuit 2 between the heater 10 and the water-refrigerant heat exchanger 12. However, instead of this, the pump 11 may be disposed in the hot water circuit 2 at a position other than between the heater 10 and the water-refrigerant heat exchanger 12.

[0171] (4) In the second embodiment, the hot water outlet 12b of the water-refrigerant heat exchanger 12 in the hot water circuit 2 An example has been described in which the water-refrigerant heat exchanger 51 and the electric heater 13 are arranged between the heater 10 and the hot water inlet 10a as a plurality of heater devices.

[0172] However, instead of this, three or more heater devices for heating hot water may be arranged as multiple heater devices between the hot water outlet 12b of the water-refrigerant heat exchanger 12 and the hot water inlet 10a of the heater 10 in the hot water circuit 2.

[0173] (5) In the above first, second and third embodiments, an example has been described in which hot water (i.e., water) is used as a heat medium for transferring heat of the refrigerant in the refrigeration cycle device 3 for refrigeration to the heater 10. However, instead of this, a heat medium other than hot water may be used as a heat medium for transferring heat of the refrigerant in the refrigeration cycle device 3 for refrigeration to the heater 10.

[0174] (6) In the above third embodiment, an example has been described in which the hot water outlet 80a of the hot water pipe 80 and the hot water inlet 81a of the hot water pipe 81 are configured to be detachable by the connecting hose 70. However, instead of this, the hot water outlet 80a of the hot water pipe 80 and the hot water inlet 81a of the hot water pipe 81 may be configured to be detachable by a connecting member other than the connecting hose 70.

[0175] For example, a first connection member is provided on the hot water outlet 80a side of the hot water pipe 80, and a second connection member is provided on the hot water inlet 81a side of the hot water pipe 81. The first connection member and the second connection member are configured to be detachable from each other.

[0176] As a result, the hot water pipes 80 and 81 are configured to be detachable by the first connecting member and the second connecting member. In this case, the hot water pipes 80 and 81 may be configured by pipes (e.g., rubber hoses) that are made of a resin material such as rubber and are capable of elastic deformation.

[0177] The hot water circuit 2 including the hot water pipe 80 and the hot water pipe 81 configured as described above has the first connecting member and the second connecting member removed by the refrigerated vehicle manufacturer. Then, the hot water outlet 80a of the hot water pipe 80 is connected to the hot water inlet 12a of the water-refrigerant heat exchanger 12. The hot water inlet 81a of the hot water pipe 81 is connected to the hot water outlet 12b of the water-refrigerant heat exchanger 12. In this way, the water-refrigerant heat exchanger 12 is disposed between the hot water outlet 80a of the hot water pipe 80 and the hot water inlet 81a of the hot water pipe 81 in the hot water circuit 2.

[0178] (7) Note that the present disclosure is not limited to the above-described embodiments, and can be appropriately modified within the scope of the claims. The above-described embodiments are not unrelated to each other, and can be appropriately combined, except when the combination is clearly impossible. It goes without saying that the elements constituting the embodiments in the above-described embodiments are not necessarily essential, except when they are particularly specified as essential or when they are clearly considered essential in principle. In addition, in the above-described embodiments, when it is described that external environment information of the vehicle (e.g., humidity outside the vehicle) is acquired from a sensor, it is also possible to eliminate the sensor and receive the external environment information from a server or cloud outside the vehicle. Alternatively, it is also possible to eliminate the sensor, acquire related information related to the external environment information from a server or cloud outside the vehicle, and estimate the external environment information from the acquired related information. [Explanation of symbols]

[0179] 1. Heat exchange system 2 Hot water circuit 3 Refrigeration cycle equipment for refrigeration 10 Heater 11 Pump 12 Water-refrigerant heat exchanger 13 Electric heater 14 Temperature Sensor 15 Air conditioning control device 16 Hot water piping 17 Hot water piping

Claims

1. a refrigeration cycle device (3) comprising a compressor (20) which draws in a refrigerant from a suction port (20a), compresses it, and discharges it from a discharge port (20b); and a heat exchanger (12) which heats a heat medium by the latent heat of condensation of the refrigerant when the refrigerant discharged from the discharge port is condensed, the refrigerant that has passed through the heat exchanger is introduced to the suction port to circulate the refrigerant, and a vapor compression refrigeration cycle is used which uses the refrigerant whose saturated vapor pressure is 2 MPa or more in absolute pressure when the refrigerant temperature is 60° C. when the refrigerant is condensed; a heat medium circuit (2) including a heater device (13) that heats the heat medium that has absorbed heat from the refrigerant in the heat exchanger, and a heat dissipation device (10) that dissipates heat from the heat medium heated by the heater device to a heat dissipation target (30); A flow path through which the heat medium flows from the heat medium outlet (10b) of the heat radiating device to the heat medium inlet (12a) of the heat exchanger is defined as a first heat medium flow path (16a), and a flow path through which the heat medium flows from the heat medium outlet (12b) of the heat exchanger to the heat medium inlet (10a) of the heat radiating device is defined as a second heat medium flow path (17a), the heater device is disposed in the second heat medium flow path of the first heat medium flow path and the second heat medium flow path, The heat medium circuit is a heat exchange system in which the heat medium flows through the heater device, the heat dissipation device, the heat exchanger, and the heater device in this order, thereby circulating the heat medium through the first heat medium flow path and the second heat medium flow path.

2. A plurality of heater devices (13, 51) are arranged in series between the heat medium outlet of the heat exchanger and the heat medium inlet of the heat radiator, and the heating COP becomes lower as the distance from the heat medium outlet of the heat exchanger approaches the heat medium inlet of the heat radiator; a temperature control unit (15) that controls a first heater device (13) having the lowest heating COP among the plurality of heater devices to adjust the amount of heat radiated from the first heater device to the heat medium; a temperature detection unit (14) that detects a temperature of the heat medium flowing from the first heater device to the heat medium inlet of the heat dissipation device, 2. The heat exchange system according to claim 1, wherein, when a second heater device (51) other than the first heater device among the plurality of heater devices heats the heat medium, the temperature control unit controls the first heater device so as to bring the temperature of the heat medium closer to a target temperature based on the temperature detected by the temperature detection unit.

3. A heat exchange system applied to a refrigerated vehicle equipped with a freezer (40), 3. The heat exchange system according to claim 1, wherein the refrigeration cycle device comprises: a pressure reducing valve (22) that reduces the pressure of the refrigerant discharged from the compressor; and an evaporator (23) in which the refrigerant reduced in pressure by the pressure reducing valve absorbs heat from inside the freezer to evaporate the refrigerant.

4. a heat medium circuit (2) including a heater device (13) for heating a heat medium, a heat dissipation device (10) for dissipating heat from the heat medium heated by the heater device to a heat dissipation target (30), a first heat medium pipe (80) for guiding the heat medium discharged from a heat medium outlet (10b) of the heat dissipation device to a heat medium inlet (13a) of the heater device, and a second heat medium pipe (81) for guiding the heat medium that has passed through the first heat medium pipe to the heat medium inlet of the heater device, the heat medium outlet (80a) of the first heat medium pipe and the heat medium inlet (81a) of the second heat medium pipe being configured to be detachable; A heat exchanger (12) is disposed between the heat medium outlet (80a) of the first heat medium piping and the heat medium inlet (81a) of the second heat medium piping; When the heat exchanger is disposed between the heat medium outlet of the first heat medium piping and the heat medium inlet of the second heat medium piping, the heat exchanger forms a vapor compression refrigeration cycle in which, when the refrigerant discharged from a compressor (20) that draws in, compresses, and discharges the refrigerant is condensed, the heat medium is heated by the latent heat of condensation of the refrigerant, and the refrigerant is circulated together with the compressor; The vapor compression refrigeration cycle uses a refrigerant whose saturation pressure is 2 MPa or more in absolute pressure when the refrigerant temperature is 60° C. when the refrigerant is condensed, When a flow path through which the heat medium flows from the heat medium outlet (10b) of the heat radiating device to the heat medium inlet (12a) of the heat exchanger is defined as a first heat medium flow path (16a), and a flow path through which the heat medium flows from the heat medium outlet (12b) of the heat exchanger to the heat medium inlet (10a) of the heat radiating device is defined as a second heat medium flow path (17a), the heater device is disposed in the second heat medium flow path of the first heat medium flow path and the second heat medium flow path, The heat medium circuit is a heat exchange system in which the heat medium flows through the heater device, the heat dissipation device, the heat exchanger, and the heater device in this order, thereby circulating the heat medium through the first heat medium flow path and the second heat medium flow path.

5. The heat medium circuit includes a connecting hose (70) that connects the heat medium outlet of the first heat medium piping and the heat medium inlet of the second heat medium piping, 5. The heat exchange system according to claim 4, wherein a space between the heat medium outlet of the first heat medium piping and the heat medium inlet of the second heat medium piping is a space in which the heat exchanger is disposed by removing the connecting hose.

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