Vehicle-mounted temperature control device

Abstract

Vehicle-mounted temperature control device (1) used in a vehicle, the vehicle having an engine for propelling the vehicle, a battery supplying electrical power to the engine, and a power control unit (PCU) controlling the electrical power supplied to the engine, the vehicle-mounted temperature control device (1) comprising: a first heating circuit (3) having a battery heat exchanger (37) exchanging heat with the battery, a PCU heat exchanger (38) exchanging heat with the power control unit (PCU), a radiator (33), and a first heat exchanger (27) configured such that the first heating medium circulates through these; and a refrigeration circuit (2) comprising a second heat exchanger (22) transferring heat from a refrigerant to something other than the refrigerant and the first heating medium to cause the refrigerant to condense.and has the first heat exchanger (27) which absorbs heat from the first heat medium to the refrigerant in order to cause the refrigerant to evaporate, and which is designed to realize a refrigeration circuit through the refrigerant circulating through it, wherein the first heat circuit (3) is designed to be able to switch between connection states of a first state in which the battery heat exchanger (37) and the first heat exchanger (27) are connected such that the first heat medium flows through them, the PCU heat exchanger (38) and the radiator (33) are connected such that the first heat medium flows through them, and the battery heat exchanger (37) and the first heat exchanger (27) are not connected to the PCU heat exchanger (38) and the radiator (33) in a state in which the first heat medium flows through them, and a second state in which the first heat exchanger (27), the PCU heat exchanger (38) and the radiator (33) are connected in such a way,that the first heat medium flows through these, characterized in that if a temperature of the battery is higher than the reference battery temperature, a connection state of the first heat circuit (3) is set to the second state and a state is set in which the battery heat exchanger (37) is not connected to the first heat exchanger (27), the PCU heat exchanger (38) and the radiator (33) in such a way that the first heat medium flows through them.

Description

AREA The present invention relates to a vehicle-mounted temperature control device. BACKGROUND In the past, a vehicle-mounted temperature control device comprising a refrigeration circuit and a low-temperature circuit has been proposed (for example, PTL 1). The refrigeration circuit is designed to implement a cooling cycle through the circulation of a refrigerant. The low-temperature circuit has a heat exchanger that exchanges heat with a heat-generating device, such as a power control unit (PCU) or a battery, and a low-temperature radiator. In such a vehicle-mounted temperature control device, the refrigeration circuit and the low-temperature circuit share a single radiator. This radiator transfers heat from the cooling water of the low-temperature circuit to the refrigerant to cause the refrigerant in the refrigeration circuit to evaporate. Furthermore, the vehicle-mounted temperature control device according to PTL 1 includes a condensing element in the refrigeration circuit that radiates heat to the outside to cause the refrigerant to condense. This radiated heat is used to heat a passenger compartment of a vehicle in which the vehicle-mounted temperature control device is installed. [CITING LIST] [PATENT LITERATURE] [PTL 1] JP 2015-186989 A US 2016 / 0318370 A1 discloses a vehicle-mounted temperature control device according to the preamble of claim 1. Further vehicle-mounted temperature control devices are known from JP 2011-073536 A and JP 2019-043262 A. SUMMARY [TECHNICAL PROBLEM] In this respect, in a vehicle-mounted temperature control device of the design described above, the low-temperature circuit preferably has the following functions. The first function is to enable the circulation of the heat transfer medium through the radiator and the cooler in a single-flow state of the low-temperature circuit. Because of this function, when the vehicle compartment is heated, the heat absorbed from the outside air by the radiator of the low-temperature circuit is used for heating. Furthermore, the second function is to enable the circulation of the heat transfer medium through the PCU heat exchanger and the radiator in a single-flow state of the low-temperature circuit. Because of this function, it is possible for the PCU to absorb heat and release this heat to the radiator of the low-temperature circuit. Furthermore, the third function is to enable constant circulation of the heat transfer medium through the PCU heat exchanger in the low-temperature circuit. The amount of heat generated by the PCU sometimes increases temporarily, for example, due to rapid acceleration, but even in such a case, the constant circulation of the heat transfer medium to the PCU heat exchanger prevents the PCU component from exceeding its thermal resistance temperature. The fourth function is to enable the circulation of the heat transfer medium through the battery heat exchanger and the radiator in a single-flow state within the low-temperature circuit. This function allows heat to be absorbed by the battery heat exchanger and transferred to the radiator in the low-temperature circuit. Furthermore, the fifth function is to enable the circulation of a heat transfer fluid, cooled by the radiator, through the battery in a single-flow state of the low-temperature circuit. This function allows the battery to be cooled quickly when it is at a high temperature. However, in the vehicle-mounted temperature control device described in PTL 1, only some of these five functions are fulfilled. The functions of the low-temperature circuit were insufficient. In view of the above problem, it is an object of the present invention to provide a vehicle-mounted temperature control device which is equipped with a low-temperature circuit which is designed to have the necessary functions. [SOLUTION TO THE PROBLEM] The object of the invention is achieved with a vehicle-mounted temperature control device according to claim 1. Advantageous embodiments of the invention are the subject of the dependent claims. [BENEFICIAL EFFECTS OF THE INVENTION] According to the present disclosure, a vehicle-mounted temperature control device is provided which is equipped with a low-temperature circuit designed to have the necessary functions. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view of the assembly, schematically showing a vehicle-mounted temperature control device. Fig. 2 is a view of the design, schematically showing an air passage for air conditioning a vehicle in which the vehicle-mounted temperature control device is installed. Fig. 3 is a view schematically showing the vehicle in which the vehicle-mounted temperature control device is installed. Fig. 4 shows an example of the operating state of the vehicle-mounted temperature control device when the low-temperature circuit is in a first mode. Fig. 5 shows an example of the operating state of the vehicle-mounted temperature control device when the low-temperature circuit is in the first mode.Figure 6 shows an example of the operating state of the vehicle-mounted temperature control device when the low-temperature circuit is in the first mode. Figure 7 shows an example of the operating state of the vehicle-mounted temperature control device when the low-temperature circuit is in the second mode. Figure 8 shows an example of the operating state of the vehicle-mounted temperature control device when the low-temperature circuit is in the second mode. Figure 9 shows an example of the operating state of the vehicle-mounted temperature control device when the low-temperature circuit is in the second mode. Figure 10 shows an example of the operating state of the vehicle-mounted temperature control device when the low-temperature circuit is in the third mode.Fig. 11 shows an example of the operating state of the vehicle-mounted temperature control device when the low-temperature circuit is in mode three. Fig. 12 shows an example of the operating state of the vehicle-mounted temperature control device when the low-temperature circuit is in mode three. Fig. 13 shows an example of the operating state of the vehicle-mounted temperature control device when the low-temperature circuit is in mode four. Fig. 14 is part of a flowchart showing an example of a control routine that controls the vehicle-mounted temperature control device. Fig. 15 is part of a flowchart showing an example of a control routine that controls the vehicle-mounted temperature control device. DESCRIPTION OF EXAMPLES OF EXECUTION The following sections explain exemplary embodiments in detail with reference to the drawings. It should be noted that, in the following explanation, identical components are assigned the same reference numerals. Design of the vehicle-mounted temperature control device With reference to Figures 1, 2 to 3, the design of a vehicle-mounted temperature control device 1 according to an exemplary embodiment is explained. Figure 1 is a view of the design, which schematically shows the vehicle-mounted temperature control device 1. In the present exemplary embodiment, the vehicle-mounted temperature control device 1 is specifically mounted in an electric vehicle driven by a motor. The vehicle-mounted temperature control device 1 has a refrigeration circuit 2, a low-temperature circuit (first heating circuit) 3, a high-temperature circuit (second heating circuit) 4 and a control device 5. First, refrigeration circuit 2 is explained. Refrigeration circuit 2 has a compressor 21, a refrigerant line 22a of a condenser 22, a receiving device 23, a first expansion valve 24, a second expansion valve 25, an evaporator 26, a refrigerant line 27a of the cooler 27, a first control valve 28, and a second control valve 29. Refrigeration circuit 2 is designed to create a refrigeration cycle by circulating a refrigerant through these components. The refrigerant used is, for example, a hydrofluorocarbon (e.g., HFC-134a) or any other substance commonly used as a refrigerant in refrigeration circuits. Refrigeration circuit 2 is divided into a refrigerant base flow path 2a, an evaporator flow path 2b, and a cooler flow path 2c. The evaporator flow path 2b and the cooler flow path 2c are parallel to each other and are each connected to the refrigerant base flow path 2a. On the refrigerant base flow path 2a, the compressor 21, the refrigerant line 22a of the condenser 22, and the receiving device 23 are arranged in this order, circulating the refrigerant in one direction. On the evaporator flow path 2b, the first control valve 28, the first expansion valve 24, and the refrigerant line 27a of the evaporator 26 are arranged in this order, circulating the refrigerant in one direction. Furthermore, on the cooler flow path 2c, the second control valve 29, the second expansion valve 25, and the cooler 27 are arranged in this order. In refrigerant flow path 2a, the refrigerant flows regardless of whether the first control valve 28 and the second control valve 29 are open or closed. If the refrigerant flows to refrigerant flow path 2a, it flows through the compressor 21, the refrigerant line 22a of the condenser 22, and the receiving device 23 in that order. In evaporator flow path 2b, the refrigerant flows when the first control valve 28 is open. If the refrigerant flows to evaporator flow path 2b, it flows through the first control valve 28, the first expansion valve 24, and the refrigerant line 27a of the evaporator 26 in that order. The refrigerant flows to cooler flow path 2c when the second control valve 29 is open. If the refrigerant flows to the cooler flow path 2c, the refrigerant flows through the second control valve 29, the second expansion valve 25 and the cooler 27 in that order. The compressor 21 functions as a compressor that compresses the refrigerant to increase its temperature. In the present embodiment, the compressor 21 is electrically driven and is designed such that its output capacity can be continuously varied by adjusting the electrical power supplied to the compressor 21. In the compressor 21, the predominantly gaseous refrigerant with low temperature and low pressure, which flows from the evaporator 26 or the condenser 27, is adiabatically compressed, thereby transforming it into a predominantly gaseous refrigerant with high temperature and high pressure. The condenser 22 is equipped with the refrigerant line 22a and the cooling water line 22b. The condenser 22 functions as a second heat exchanger for transferring heat from the refrigerant to something other than the refrigerant and cooling water of the low-temperature circuit 3, which will be explained later, in order to cause the refrigerant to condense. In the present embodiment, the condenser 22 exchanges heat between the refrigerant flowing through the refrigerant line 22a and the cooling water flowing through the cooling water line 22b, which will be explained later, and transfers the heat from the refrigerant to this cooling water. The refrigerant line 22a of the condenser 22 functions as a condenser that condenses the refrigerant in the refrigeration circuit.Furthermore, in the refrigerant line 22a of the condenser 22, the mainly gaseous refrigerant with a high temperature and high pressure, which flows out of the compressor 21, is changed into a mainly liquid refrigerant with a high temperature and high pressure by isobaric cooling. The receiving device 23 stores the refrigerant that has condensed through the refrigerant line 22a of the condenser 22. Furthermore, not all of the refrigerant can necessarily be liquefied in the condenser 22, and therefore the receiving device 23 is designed to separate the gas and a liquid. Only the liquid refrigerant, separated from the gaseous refrigerant, flows out of the receiving device 23. It should be noted that, instead of the receiving device 23, the refrigeration circuit 2 can also use a secondary cooling condenser, which incorporates a gas-liquid separator, as the condenser 22. The first expansion valve 24 and the second expansion valve 25 function as expansion devices that cause the refrigerant to expand. These expansion valves 24 and 25 are equipped with small-diameter passages and spray a refrigerant from these passages to rapidly reduce the refrigerant pressure. The first expansion valve 24 sprays a mist of liquid refrigerant, supplied by the receiving device 23, into the evaporator 26. Similarly, the second expansion valve 25 sprays a mist of liquid refrigerant, supplied by the receiving device 23, into the refrigerant line 27a of the cooler 27.In these expansion valves 24 and 25, the liquid refrigerant, which flows out of the receiving device 23 at a high temperature and high pressure, is depressurized and partially evaporates, thus changing into a misty refrigerant at a low temperature and low pressure. It should be noted that the expansion valves can be of a mechanical type with fixed superheat levels or of an electrical type that can adjust the superheat levels. Furthermore, instead of the first expansion valve 24 and the second expansion valve 25, for example, ejection devices or other devices besides the expansion devices can be used if it is possible to cause the refrigerant to expand to reduce its pressure. The evaporator 26 functions as an evaporator, causing the refrigerant to evaporate. Specifically, the evaporator 26 causes the refrigerant to absorb heat from the air surrounding it, thus evaporating. Therefore, within the evaporator 26, the low-temperature, low-pressure, misty refrigerant flowing from the first expansion valve 24 is transformed into a low-temperature, low-pressure gaseous refrigerant through evaporation. As a result, the air surrounding the evaporator 26 can be cooled, and the passenger compartment can be cooled. The cooler 27 is equipped with the refrigerant line 27a and the cooling water line 27b. The cooler 27 functions as the first heat exchanger, causing the refrigerant to absorb heat from the cooling water of the low-temperature circuit 3, which will be described later, in order to evaporate the refrigerant. In the present embodiment, the cooler 27 exchanges heat between the cooling water flowing through the cooling water line 27b, which will be described later, and the refrigerant flowing through the refrigerant line 27a, and transfers heat from this cooling water to the refrigerant. The refrigerant line 27a of the cooler 27 functions as an evaporator to cause the refrigerant to evaporate.Furthermore, in the refrigerant line 27a of the cooler 27, the low-temperature, low-pressure, misty refrigerant flowing from the second expansion valve 25 evaporates, thereby changing it into a low-temperature, low-pressure gaseous refrigerant. As a result, the cooling water of the low-temperature circuit 3 is cooled. The first control valve 28 and the second control valve 29 are used to change the refrigerant circulation mode in the refrigeration circuit 2. The greater the opening degree of the first control valve 28, the greater the amount of refrigerant flowing into the evaporator flow path 2b. Consequently, the amount of refrigerant flowing into the evaporator 26 increases. Furthermore, the greater the opening degree of the second control valve 29, the greater the amount of refrigerant flowing into the cooler flow path 2c, and consequently, the greater the amount of refrigerant flowing into the cooler 27. It should be noted that in the present embodiment, the control valve 28 is designed as a valve whose opening degree can be adjusted, but it can also be an ON / OFF valve that switches between an open and a closed state.Furthermore, instead of the first control valve 28 and the second control valve 29, it is also possible to provide a three-way valve that can selectively direct the refrigerant flow from the refrigerant base flow path 2a to only the evaporator flow path 2b, only the cooler flow path 2c, and / or to both. Therefore, if it is possible to adjust the flow rate from the refrigerant base flow path 2a to the evaporator flow path 2b and the cooler flow path 2c, any type of valve can be provided as the circulation mode control device instead of these control valves 28 and 29. Next, the low-temperature circuit 3 will be explained. The low-temperature circuit 3 has a first pump 31, a second pump 32, the cooling water line 27b of the radiator 27, a low-temperature radiator 33, a first three-way valve 34, a second three-way valve 35, and a four-way valve 36. Furthermore, the low-temperature circuit 3 has the battery heat exchanger 37, the PCU heat exchanger 38, and an engine heat exchanger 39. In the low-temperature circuit 3, the cooling water circulates through these components. It should be noted that the cooling water is an example of the first heat transfer medium. A different heat transfer medium can be used instead of the cooling water within the low-temperature circuit 3. The low-temperature circuit 3 has a first sub-circuit 3a, a second sub-circuit 3b and two bypass flow paths 3c and 3d. The first sub-circuit 3a and the second sub-circuit 3b are connected to each other by the four-way valve 36. The first sub-circuit 3a comprises the first pump 31, the battery heat exchanger 37, the cooling water line 27b of the radiator 27, and the four-way valve 36, arranged in that order in the direction of cooling water circulation. Furthermore, a first bypass flow path 3c, designed to bypass the battery heat exchanger 37, is connected to the first sub-circuit 3a. In the present embodiment, one end of the first bypass flow path 3c is connected between the first pump 31 and the battery heat exchanger 37 in the direction of cooling water circulation. The other end of the first bypass flow path 3c is connected between the radiator 27 and the battery heat exchanger. Furthermore, in the second sub-circuit 3b, the low-temperature radiator 33, the second pump 32, the PCU heat exchanger 38, the four-way valve 36, and the engine heat exchanger 39 are arranged in that order in the direction of coolant circulation. The second sub-circuit 3b may also include a heat exchanger that exchanges heat with a heat-generating device other than the battery, the MG, and the PCU. The second bypass flow path 3d is connected to the first subcircuit 3a and the second subcircuit 3b to link these circuits. Specifically, one end of the second bypass flow path 3d is connected to the second subcircuit 3b between the engine heat exchanger 39 and the low-temperature radiator 33, while the other end of the second bypass flow path 3d is connected to the first subcircuit 3a between the coolant line 27b of the radiator 27 and the four-way valve 36. It should be noted that, as long as the engine heat exchanger 39 can be bypassed, the second bypass flow path 3d need not be connected to both the first subcircuit 3a and the second subcircuit 3b and may be connected to only the second subcircuit 3b. The first pump 31 and the second pump 32 pump the cooling water that circulates through the low-temperature circuit 3. In the present embodiment, the first pump 31 and the second pump 32 are electrically driven water pumps and are designed to allow their output capacities to be continuously varied by adjusting the electrical power supplied to the first pump 31 and the second pump 32. The low-temperature radiator 33 is a heat exchanger that exchanges heat with the coolant circulating through the low-temperature circuit 3 and the vehicle's outside air 100 (ambient air). The low-temperature radiator 33 is designed to transfer heat from the coolant to the outside air when the coolant temperature is higher than the outside air temperature, and to absorb heat from the outside air to the coolant when the coolant temperature is lower than the outside air temperature. The first three-way valve 34 is designed to control the circulation mode of the cooling water flowing from the first pump 31 and to allow the flow destination of the cooling water to be selectively changed between the battery heat exchanger 37 and the first bypass flow path 3c. In the first sub-circuit 3a, when the first three-way valve 34 is set to the side of the battery heat exchanger 37, the cooling water flows through the first pump 31, the battery heat exchanger 37, and the cooling water line 27b of the radiator 27 in that order. Conversely, when the first three-way valve 34 is set to the side of the first bypass flow path 3c, the cooling water does not circulate through the battery heat exchanger 37 and therefore flows only through the first pump 31 and the cooling water line 27b of the radiator 27. The second three-way valve 35 is located at the connection between the first sub-circuit 3a and the second bypass flow path 3d. The second three-way valve 35 controls the flow mode of the cooling water exiting the cooler 27 and is designed to selectively change the component into which the cooling water flows, either the four-way valve 36 or the low-temperature radiator 33. When the second three-way valve 35 is set to the side of the four-way valve 36, the cooling water flows through the cooling water line 27b of the cooler 27, the three-way valve 35, and the four-way valve 36 in that order. Conversely, when the second three-way valve 35 is set to the side of the low-temperature radiator 33, the cooling water flows through the cooling water line 27b of the cooler 27, the three-way valve 35, and the low-temperature radiator 33 in that order. It should be noted that, provided it is possible to adjust the flow rate of the cooling water flowing into the battery heat exchanger 37 and the first bypass flow path 3c appropriately, a control valve or an ON / OFF valve or other device for controlling the flow mode may be used instead of the first three-way valve 34. Similarly, provided it is possible to adjust the flow rate of the cooling water flowing into the four-way valve 36 and the low-temperature radiator 33 appropriately, a control valve or an ON / OFF valve or other device for controlling the flow mode may be used instead of the second three-way valve 35. In particular, with regard to the first three-way valve 34, as long as it is designed such that, when the low-temperature circuit 3 is in the second state explained later, it allows a switching of the flow state between the state of connecting the battery heat exchanger 37 to the cooler 27, the PCU heat exchanger 38 and the low-temperature radiator 33, so that cooling water flows through them, and the state of not connecting the battery heat exchanger 37 to the cooler 27, the PCU heat exchanger 38 and the low-temperature radiator 33, so that cooling water does not flow through them, any type of flow mode control device may be used. Furthermore, with regard to the second three-way valve 35, as long as it is designed in such a way that, when the low-temperature circuit 3 is in the second state explained later, it allows a switching of the connection state between the state of connecting the engine heat exchanger 39 to the cooler 27, the PCU heat exchanger 38 and the low-temperature radiator 33, so that coolant flows through them, and the state of not connecting the engine heat exchanger 37 to the cooler 27, the PCU heat exchanger 38 and the low-temperature radiator 33, so that coolant does not flow through them, any type of flow mode control device can be used. Furthermore, if the second bypass flow path 3d is connected to only the second subcircuit 3b, the second three-way valve 35 is designed to allow a component into which the cooling water flows to be selectively changed between the engine heat exchanger 39 and the second bypass flow path 3d. The four-way valve 36 is provided at a connection point between the first sub-circuit 3a and the second sub-circuit 3b and controls the flow mode of the cooling water between the first sub-circuit 3a and the second sub-circuit 3b. Specifically, the four-way valve 36 can switch the connection state between a first state in which the first sub-circuit 3a and the second sub-circuit 3b are not connected to each other, and a state in which the first sub-circuit 3a and the second sub-circuit 3b are connected to each other.Therefore, when the four-way valve 36 is in the first state, the battery heat exchanger 37 and the radiator 27 are connected such that the cooling water flows through them, and the PCU heat exchanger 38 and the low-temperature radiator 33 are connected such that the cooling water flows through them, while the battery heat exchanger 37 and the radiator 27 and the PCU heat exchanger 38 and the low-temperature radiator 33 are not connected in a state in which the cooling water flows through them. On the other hand, when the four-way valve 36 is in the second state, the radiator 27, the PCU heat exchanger 38, and the low-temperature radiator 33 are connected such that the cooling water flows through them. In the present embodiment, the four-way valve 36 is located in the first sub-circuit 3a between the cooler 27 and the first pump 31, and in the second sub-circuit 3b between the PCU heat exchanger 38 and the engine heat exchanger 39. Furthermore, when the four-way valve 36 is in the first state, the first sub-circuits 3a and the second sub-circuits 3b are connected. Conversely, when the four-way valve 36 is in the second state, the side of the first sub-circuit 3a located at the first pump 31 and the side of the second sub-circuit 3b located at the PCU heat exchanger 38 are connected, and the side of the first sub-circuit 3a located at the second three-way valve 35 and the side of the second sub-circuit 3b located at the engine heat exchanger 39 are connected. As a consequence, in the present embodiment, when the four-way valve 36 is in the first state, a portion of the cooling water flows through the first pump 31, the battery heat exchanger 37, and the radiator 27 in that order, and, separately and independently, the remaining cooling water flows through the low-temperature radiator 33, the PCU heat exchanger 38, and the engine heat exchanger 39 in that order. Conversely, when the four-way valve 36 is in the second state, the cooling water flows through the low-temperature radiator 33, the PCU heat exchanger 38, the first pump 31, the battery heat exchanger 37, the radiator 27, and the engine heat exchanger 39 in that order. Whatever the case, when the four-way valve 36 is in the second state, the cooling water preferentially flows through at least the low-temperature radiator 33, the PCU heat exchanger 38 and the engine heat exchanger 39 in that order. In the present embodiment, the low-temperature circuit 3 is designed to switch the connection state between the first state and the second state. Furthermore, in the first state of the low-temperature circuit 3, the battery heat exchanger 37 and the cooler 27 are connected such that the cooling water flows through them, and the PCU heat exchanger 38 and the low-temperature radiator 33 are connected such that the cooling water flows through them, while the battery heat exchanger 37 and the cooler 27, and the PCU heat exchanger 38 and the low-temperature radiator 33 are not connected in a state in which the cooling water flows through them. Furthermore, in the second state of the low-temperature circuit 3, the cooler 27, the PCU heat exchanger 38, and the low-temperature radiator 33 are connected such that the cooling water flows through them. In particular, in the present embodiment, when the low-temperature circuit 3 is in the first state, the engine heat exchanger 39 is connected to the PCU heat exchanger 38 and the low-temperature radiator 33 in such a way that the cooling water flows through them, and the battery heat exchanger 37 and the radiator 27 are not connected to the PCU heat exchanger 38, the low-temperature radiator 33 and the engine heat exchanger 39 in a state in which the cooling water flows through them. It should be noted that, as explained above, as long as it is possible to switch connection states in the low temperature circuit 3, a variety of ON / OFF valves or other connection state control devices may be used instead of the four-way valve 36. The battery heat exchanger 37 functions as a "heat-generating device"—a heat exchanger for exchanging heat with a battery (not shown) of the vehicle 100, which is itself a heat-generating device. Specifically, the battery heat exchanger 37 is provided with a conduit that encircles the battery and is designed to exchange heat between the coolant flowing through the conduit and the battery. It should be noted that the battery of the vehicle 100 is connected to the PCU and the motor of the vehicle 100, which will be explained later, and supplies electrical power to the motor to drive the vehicle 100.It should be noted that in the present embodiment, the motor used to drive the vehicle 100 is a motor generator (MG) which has a function of generating electrical power. Furthermore, the PCU heat exchanger 38 functions as a "heat-generating device" heat exchanger for exchanging heat with a power control unit (PCU, not shown) of the vehicle 100, which is itself a heat-generating device. Specifically, the PCU heat exchanger 38 is provided with a conduit that is designed around the PCU and is configured to exchange heat between the cooling water flowing through this conduit and the battery. It should be noted that the PCU is connected between the battery and the MG and controls the electrical power supplied to the MG. The PCU has an inverter that drives the MG, a boost converter that controls the voltage, a DC-DC converter that reduces the high voltage, and other heat-generating components. The engine heat exchanger 39 functions as a "heat-generating device" heat exchanger, exchanging heat with the motor unit (MG) of the vehicle 100, which is itself a heat-generating device. Specifically, the engine heat exchanger 39 is designed to exchange heat between the oil flowing around the MG and the coolant. It should be noted that the oil flow path can be designed such that the oil exchanging heat with the engine heat exchanger 39 flows around the MG and additionally around the transmission. In this case, the engine heat exchanger 39 exchanges heat with both the MG and the transmission. It should be noted that the MG is used to propel the vehicle 100 or to regenerate power when the vehicle 100 is decelerated. Next, the high-temperature circuit 4 will be explained. The high-temperature circuit 4 has a third pump 41, the cooling water line 22b of the condenser 22, a high-temperature radiator 42, a third three-way valve 43, an electric heating device 44, and a heating device core 45. Cooling water also circulates through these components in the high-temperature circuit 4. It should be noted that this cooling water is an example of the second heat transfer medium. A different heat transfer medium can be used instead of cooling water inside the high-temperature circuit 4. Furthermore, the high-temperature circuit 4 is divided into a high-temperature base flow path 4a, a radiator flow path 4b, and a heating device flow path 4c. The radiator flow path 4b and the heating device flow path 4c are arranged parallel to each other and are each connected to the high-temperature base flow path 4a. In the high-temperature base flow path 4a, a third pump 41 and the cooling water line 22b of the condenser 22 are provided in this order, in the direction of cooling water circulation. In the radiator flow path 4b, a high-temperature radiator 42 is provided. Furthermore, in the heating device flow path 4c, an electric heating device 44 and a heating device core 45 are provided in this order, in the direction of cooling water circulation. A third three-way valve 43 is provided between the high-temperature base flow path 4a and the radiator flow path 4b and the heating device flow path 4c. The third pump 41 pumps the cooling water that circulates through the high-temperature circuit 4. In the present embodiment, the third pump 41 is an electric water pump, identical to the first pump 31. Furthermore, the high-temperature radiator 42, like the low-temperature radiator 33, is a heat exchanger that exchanges heat between the cooling water circulating through the high-temperature circuit 4 and the outside air. The third three-way valve 43 functions as a circulation mode control device, controlling the circulation mode of the cooling water flowing out of the cooling water line 22b of the condenser 22. It is designed to selectively change the direction of circulation between the radiator flow path 4b and the heating device flow path 4c. If the third three-way valve 43 is fixed on the radiator flow path 4b side, the cooling water flowing out of the cooling water line 22b of the condenser 22 flows through the radiator flow path 4b. Conversely, if the third three-way valve 43 is fixed on the heating device flow path 4c side, the cooling water flowing out of the cooling water line 22b of the condenser 22 flows through the electric heating device 44 and the heating device core 45.It should be noted that if it is possible to adjust the flow rate of the cooling water flowing into the radiator flow path 4b and the heating device flow path 4c in a suitable manner, an adjustment valve or an ON / OFF valve or other circulation mode control device may be used instead of the three-way valve 43. The electric heating device 44 functions as a heating device that heats the cooling water. The electric heating device 44 is, for example, equipped with a resistance heating element arranged around the conduit through which the cooling water flows, and is designed such that the cooling water in the conduit is heated by supplying electrical power to this resistance heating element. The electric heating device 44 is used, for example, for heating when the ambient air temperature is extremely low and, as a consequence, the refrigerant in the refrigeration circuit 2 does not function properly. It should be noted that the electric heating device 44 can be arranged in a different position, as long as the cooling water heated by the electric heating device can be supplied to the heating device core 45.In particular, the electric heating device 44 can, for example, be provided in the high-temperature base flow path 4a between the condenser 22b and the third three-way valve 43. The heating unit core 45 is designed to exchange heat between the cooling water circulating through the high-temperature circuit 4 and the air surrounding the heating unit core 45, thereby heating the passenger compartment. Specifically, the heating unit core 45 is designed to transfer heat from the cooling water to the air surrounding it. Therefore, when high-temperature cooling water flows to the heating unit core 45, the temperature of the cooling water is reduced, and the air surrounding the heating unit core 45 is heated. Fig. 2 is a schematic view of the design showing the air passage 6 for air conditioning the vehicle 100, in which the vehicle-mounted temperature control device 1 is installed. Air flows through the air passage 6 in the direction indicated by the arrows in the figure. The air passage 6 shown in Fig. 2 is connected to the exterior of the vehicle 100 or to the air intake openings of the passenger compartment. Outside air or air inside the passenger compartment flows into the air passage 6 according to the state of control by the control device 5. Furthermore, the air passage 6 shown in Fig. 2 is connected to ventilation openings that blow air into the passenger compartment. Air is supplied from the air passage 6 to one of the ventilation openings according to the state of control by the control device 5. As shown in Fig. 2, in the air passage 6 for air conditioning of the present embodiment a blower 61, an evaporator 26, an air mixing door 62 and a heating device core 45 are provided in this order in the direction of an air flow. The blower 61 is equipped with a blower motor 61a and a blower fan 61b. The blower 61 is designed such that, if the blower fan 61b is driven by the blower motor 61a, the outside air or the air inside the passenger compartment flows into and through the air passage 6. The air mixing door 62 adjusts the flow rate of the air flowing through the heating element core 45 to that of the air flowing through the air passage 6. The air mixing door 62 is designed to be adjustable to a state in which all the air flowing through the air passage 6 passes through the heating element core 45, to a state in which none of the air flowing through the air passage 6 passes through the heating element core 45, and to states between these. In the air passage 6 thus configured, if the blower 61 is driven and the refrigerant circulates through the evaporator 26, the air flowing through the air passage 6 is cooled. Furthermore, if the blower 61 is driven and the cooling water circulates to the heating element core 45, and the air mixing door 62 is controlled such that air flows through the heating element core 45, the air flowing through the air passage 6 is heated. Fig. 3 is a schematic view of the vehicle 100 in which the vehicle-mounted temperature control device 1 is installed. As shown in Fig. 3, a low-temperature radiator 33 and a high-temperature radiator 42 are arranged on the inside of the front grille of the vehicle 100. Therefore, when the vehicle 100 is moving, wind generated by the vehicle's movement strikes these radiators 33 and 42. Furthermore, a fan 71 is provided adjacent to these radiators 33 and 42. The fan 71 is designed such that, when driven, the air strikes the radiators 33 and 42. Therefore, even when the vehicle 100 is not moving, driving the fan 71 makes it possible to cause the air to strike the radiators 33 and 42. With reference to Fig. 1, the control device 5 is provided with an electronic control unit (ECU) 51. The ECU 51 is provided with a processor for carrying out various types of processes, a memory that stores programs and various types of information, and an interface that is connected to various actuators and various sensors. Furthermore, the control device 5 is equipped with a battery temperature sensor 52, which detects the battery temperature, a first water temperature sensor 53, which detects the temperature of the cooling water flowing through the second sub-circuit 3b (in particular, the temperature of the cooling water flowing out of the second pump 32 and into the PCU heat exchanger 38), and a second water temperature sensor 54, which detects the temperature of the cooling water flowing into the heating device core 45. The ECU 51 is connected to these sensors, and output signals from these sensors are fed to the ECU 51. Furthermore, the ECU 51 is connected to and controls various types of actuators of the vehicle-mounted temperature control unit 1. Specifically, the ECU 51 is connected to and controls the compressor 21, the control valves 28 and 29, the pumps 31, 32 and 41, the three-way valves 34, 35 and 43, the four-way valve 36, the electric heating unit 44, the blower motor 61a, the air mixing door 62 and the fan 71. Operation of the vehicle-mounted temperature control device Next, typical operating conditions of the vehicle-mounted temperature control device 1 are explained with reference to Figs. 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 to 14. In Figs. 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 to 14, a flow path through which the refrigerant or cooling water flows is shown by a solid line, while a flow path through which the refrigerant or cooling water does not flow is shown by a dashed line. Furthermore, thin arrow markings in the figures indicate directions of a flow of refrigerant or cooling water, while thick arrow markings indicate directions of a movement of heat. In the present embodiment, the operating states of the low-temperature circuit 3 of the vehicle-mounted temperature control device 1 are divided into four main modes, from the first to the fourth mode. The connection states between the devices provided in the low-temperature circuit 3 differ in these operating states. These four operating states are explained below. Figures 4, 5 to 6 show the operating state of the vehicle-mounted temperature control device 1 when the operating state of the low-temperature circuit 3 is in the first mode. As can be seen from Figures 4, 5 to 6, in the first mode the first pump 31 is stopped and the second pump 32 is running. Furthermore, the four-way valve 36 is fixed in the first state. Therefore, the first sub-circuit 3a and the second sub-circuit 3b are not connected to each other. As a consequence, when the low-temperature circuit 3 is in the first operating mode, the coolant circulates in the second sub-circuit 3b of the low-temperature circuit 3 through the second pump 32, the PCU heat exchanger 38, the engine heat exchanger 39, and the low-temperature radiator 33, in that order. Therefore, the coolant in the low-temperature circuit 3 absorbs heat from the PCU and the engine heat exchanger at the PCU heat exchanger 38 and the engine heat exchanger 39, and releases heat to the outside air at the low-temperature radiator 33. As a result, the PCU and the engine heat exchanger are cooled. Conversely, since the first pump 31 is stopped, the coolant does not circulate in the first sub-circuit 3a of the low-temperature circuit 3. Therefore, there is almost no heat transfer between the coolant and the battery or refrigerant at the battery heat exchanger 37 and the radiator 27. Consequently, the battery is not cooled effectively. In particular, in the example shown in Fig. 4, the compressor 21 and the third pump 41 are also stopped. Therefore, the refrigeration circuit 2 is not implemented. Consequently, there is almost no heat transfer between the cooling water and the refrigerant in the radiator 27 and the condenser 22. The vehicle-mounted temperature control device 1 is, for example, set to the operating state shown in Fig. 4, when the battery temperature is low and neither heating nor cooling is required in the vehicle compartment 100. Furthermore, in the example shown in Fig. 5, the compressor 21 is stopped, but the third pump 41 is in operation. In addition, the three-way valve 43 of the high-temperature circuit 4 is set to the side of the heating device flow path 4c, and electrical power is supplied to the electric heating device 44. In the example shown in Fig. 5, the compressor 21 is stopped, and therefore the refrigeration cycle in refrigeration circuit 2 is not functioning. Consequently, there is almost no heat transfer between the cooling water and the refrigerant in the radiator 27 and the condenser 22. On the other hand, the cooling water in the high-temperature circuit 4 circulates through the third pump 41, the cooling water line 22b of the condenser 22, the electric heater 44, and the heater core 45, in that order. Furthermore, the temperature of the cooling water in the high-temperature circuit 4 is increased at the electric heater 44. As a result, the cooling water in the high-temperature circuit 4 absorbs heat at the electric heater 44 and releases heat to the surrounding air at the heater core 45. Due to this heat transfer, the interior of the vehicle compartment 100 is heated.The vehicle-mounted temperature control device 1 is, for example, set to the operating state shown in Fig. 5 if the battery temperature is low, heating of the interior of the vehicle compartment 100 is required, and the temperature of the coolant in the low-temperature circuit 3 is extremely low (for example, equal to or less than -20°C). Furthermore, in the example shown in Fig. 6, both the compressor 21 and the third pump 41 are in operation. In addition, the first control valve 28 of the refrigeration circuit 2 is open and the second control valve 29 is closed. Furthermore, the three-way valve 43 of the high-temperature circuit 4 is fixed to the side of the radiator flow path 4b. In the example shown in Fig. 6, the compressor 21 is in operation, and therefore the refrigerant circulates in the refrigeration circuit 2. Specifically, the first control valve 28 is open and the second control valve 29 is closed, and therefore the refrigerant circulates in the refrigeration circuit 2 through the compressor 21, the refrigerant line 22a of the condenser 22, the receiving unit 23, the first expansion valve 24, and the evaporator 26 in that order. As a result, the refrigerant in the refrigeration circuit 2 absorbs heat from the surrounding air at the evaporator 26 and releases heat to the cooling water of the high-temperature circuit 4 at the condenser 22. Due to this heat absorption, the interior of the vehicle compartment 100 is cooled. On the other hand, the cooling water in the high-temperature circuit 4 circulates through the third pump 41, the cooling water line 22b of the condenser 22, and the high-temperature radiator 42 in that order. As a result, the cooling water in the high-temperature circuit 4 absorbs heat from the refrigerant at the condenser 22 and releases heat to the atmosphere at the high-temperature radiator 42. Therefore, in the example shown in Fig. 6, the heat absorbed at the evaporator 26 is released at the high-temperature radiator 42. The vehicle-mounted temperature control device 1 is, for example, set to the operating state shown in Fig. 6 if the battery temperature is low and cooling of the interior of the vehicle compartment 100 is required. Figures 7, 8 to 9 show the operating state of the vehicle-mounted temperature control device 1 when the low-temperature circuit 3 is in the second mode. As can be seen from Figures 7, 8 to 9, in the second mode both the first pump 31 and the second pump 32 are in operation. Furthermore, the four-way valve 36 is set to the second state. Therefore, the first sub-circuit 3a and the second sub-circuit 3b are connected. Additionally, the first three-way valve 34 is set to the side of the battery heat exchanger 37, while the second three-way valve 35 is set to the side of the four-way valve 36. It should be noted that in the second mode only one of the pumps, the first pump 31 and the second pump 32, can be in operation. As a consequence, if the operating state of the low-temperature circuit 3 is in the second mode, the cooling water of the low-temperature circuit 3 circulates through the first pump 31, the battery heat exchanger 37, the coolant line 27b of the radiator 27, the engine heat exchanger 39, the low-temperature radiator 33, the second pump 32, and the PCU heat exchanger 38 in that order. Therefore, the cooling water of the low-temperature circuit 3 absorbs heat from the battery, the PCU, and the engine at the battery heat exchanger 37, the PCU heat exchanger 38, and the engine heat exchanger 39, respectively, and releases heat to the outside air at the low-temperature radiator 33. As a result, the battery, the PCU, and the engine are cooled. In particular, in the example shown in Fig. 7, the compressor 21 and the third pump 41 are stopped. Therefore, the refrigeration circuit 2 is not implemented. Consequently, there is almost no heat transfer between the cooling water and the refrigerant in the radiator 27 and the condenser 22. The vehicle-mounted temperature control device 1 is, for example, set to the operating state shown in Fig. 7, when the battery temperature is sufficiently high and neither heating nor cooling of the interior of the vehicle compartment 100 is required. Furthermore, in the example shown in Fig. 8, the compressor 21 and the third pump 41 are in operation. In addition, the first control valve 28 of the refrigeration circuit 2 is closed and the second control valve 29 is open. Furthermore, the three-way valve 43 of the high-temperature circuit 4 is fixed to the side of the heating device flow path 4c. In the example shown in Fig. 8, the compressor 21 is in operation, and therefore a refrigerant circulates in the refrigeration circuit 2. Specifically, the first control valve 28 is closed and the second control valve 29 is open, and therefore the refrigerant circulates in the refrigeration circuit 2 through the compressor 21, the refrigerant line 22a of the condenser 22, the receiving device 23, the second expansion valve 25, and the refrigerant line 27a of the cooler 27 in that order. As a result, the refrigerant in the refrigeration circuit 2 absorbs heat from the cooling water of the low-temperature circuit 3 at the cooler 27 and releases heat to the cooling water of the high-temperature circuit 4 at the condenser 22. On the other hand, the third pump 41 is in operation, and therefore the cooling water in the high-temperature circuit 4 circulates through the third pump 41, the cooling water line 22b of the condenser 22, and the heating element core 45 in that order. As a result, the cooling water in the high-temperature circuit 4 absorbs heat from the refrigerant in the refrigeration circuit 2 at the condenser 22 and releases heat to the surrounding air at the heating element core 45. This heat transfer warms the interior of the vehicle compartment 100. The vehicle-mounted temperature control device 1 is, for example, set to the operating state shown in Fig. 8, when the battery temperature is high to a certain extent and heating of the interior of the vehicle compartment 100 is required. It should be noted that, as described above, when the operating state of the low-temperature circuit 3 is in the second mode, the cooling water in the low-temperature circuit 3 generally absorbs heat from the battery, the PCU, and the MG at the battery heat exchanger 37, the PCU heat exchanger 38, and the engine heat exchanger 39, respectively, and releases heat to the outside air at the low-temperature radiator 33. However, in the operating state shown in Fig. 8, when the amount of heat transferred from the cooling water of the low-temperature circuit 3 to the refrigerant of the refrigeration circuit 2 at the radiator 27 is large, the cooling water of the low-temperature circuit 3 can also absorb heat from the outside air at the low-temperature radiator 33. Furthermore, in the example shown in Fig. 9, the compressor 21 and the third pump 41 are both in operation. In addition, the first control valve 28 of the refrigeration circuit 2 is open and the second control valve 29 is closed. Furthermore, the three-way valve 43 of the high-temperature circuit 4 is fixed to the side of the radiator flow path 4b. In the example shown in Fig. 9, the compressor 21 is in operation, and therefore the refrigerant circulates in the refrigeration circuit 2. Specifically, the first control valve 28 is open and the second control valve 29 is closed, and therefore the refrigerant circulates in the refrigeration circuit 2 through the compressor 21, the refrigerant line 22a of the condenser 22, the receiving unit 23, the first expansion valve 24, and the evaporator 26 in that order. As a result, the refrigerant in the refrigeration circuit 2 absorbs heat from the surrounding air at the evaporator 26 and releases heat to the cooling water of the high-temperature circuit 4 at the condenser 22. Due to this heat absorption, the interior of the vehicle compartment 100 is cooled. On the other hand, the cooling water in the high-temperature circuit 4 circulates through the third pump 41, the cooling water line 22b of the condenser 22, and the high-temperature radiator 42 in that order. As a result, the cooling water in the high-temperature circuit 4 absorbs heat from the refrigerant at the condenser 22 and releases heat to the atmosphere at the high-temperature radiator 42. Therefore, in the example shown in Fig. 9, the heat absorbed at the evaporator 26 is released at the high-temperature radiator 42. The vehicle-mounted temperature control device 1 is, for example, set to the operating condition shown in Fig. 9, when the battery temperature is high to a certain extent and cooling of the interior of the vehicle compartment 100 is required. Figures 10, 11 to 12 show the operating state of the vehicle-mounted temperature control device 1 when the low-temperature circuit 3 is in the third mode. As can be seen from Figures 10, 11 to 12, in the third mode both the first pump 31 and the second pump 32 are in operation. Furthermore, the four-way valve 36 is set to the first state. Therefore, the first sub-circuit 3a and the second sub-circuit 3b are not connected to each other. As a consequence, if the operating state of the low-temperature circuit 3 is in the third mode, the coolant in the first sub-circuit 3a of the low-temperature circuit 3 circulates through the first pump 31, the battery heat exchanger 37, and the coolant line 27b of the radiator 27 in that order. Therefore, the coolant in the first sub-circuit 3a absorbs heat at the battery heat exchanger 37 and releases heat to the refrigerant of the refrigeration circuit 2 at the radiator 27. As a result, the battery is cooled quickly. On the other hand, the coolant in the second sub-circuit 3b of the low-temperature circuit 3 circulates through the second pump 32, the PCU heat exchanger 38, the engine heat exchanger 39, and the low-temperature radiator 33 in that order. Therefore, the coolant in the low-temperature circuit 3 absorbs heat from the PCU and the engine heat exchanger 38 and 39, respectively.The engine heat exchanger 39 transfers heat to the outside air via the low-temperature radiator 33. As a result, the PCU and the MG are cooled. In particular, in the example shown in Fig. 10, the compressor 21 and the third pump 41 are in operation. Furthermore, the first control valve 28 of the refrigeration circuit 2 is closed and the second control valve 29 is open. Additionally, the three-way valve 43 of the high-temperature circuit 4 is fixed to the side of the radiator flow path 4b. In the example shown in Fig. 10, the compressor 21 is in operation, and therefore a refrigerant circulates in the refrigeration circuit 2. Specifically, the first control valve 28 is closed and the second control valve 29 is open, and therefore the refrigerant circulates in the refrigeration circuit 2 through the compressor 21, the refrigerant line 22a of the condenser 22, the receiving device 23, the second expansion valve 25, and the refrigerant line 27a of the cooler 27, in that order. As a result, the refrigerant in the refrigeration circuit 2 absorbs heat from the cooling water in the low-temperature circuit 3 at the cooler 27 and releases heat to the cooling water of the high-temperature circuit 4 at the condenser 22. Furthermore, the third pump 41 is in operation, and therefore the cooling water in the high-temperature circuit 4 circulates through the third pump 41, the cooling water line 22b of the condenser 22, and the high-temperature radiator 42 in that order. As a consequence, the cooling water in the high-temperature circuit 4 absorbs heat from the refrigerant in the refrigeration circuit 2 at the condenser 22 and releases heat to the outside air at the high-temperature radiator 42. Therefore, the heat absorbed by the cooling water in the low-temperature circuit 3 at the radiator 27 is released to the outside air at the high-temperature radiator 42. The vehicle-mounted temperature control device 1 is, for example, set to the operating state shown in Fig. 10, when the battery temperature is extremely high and neither heating nor cooling of the interior of the vehicle compartment 100 is required. Furthermore, in the example shown in Fig. 11, the vehicle-mounted temperature control device 1 is in an operating state similar to the example shown in Fig. 10, except that the third three-way valve 43 is fixed on the side of the heating device flow path 4c. Therefore, in the example shown in Fig. 11, the cooling water in the high-temperature circuit 4 circulates through the third pump 41, the cooling water line 22b of the condenser 22, and the heating device core 45 in that order. As a result, the cooling water in the high-temperature circuit 4 absorbs heat from the refrigerant in the refrigeration circuit 2 at the condenser 22 and releases heat to the surrounding air at the high-temperature radiator 42. Due to this heat release, the interior of the vehicle compartment 100 is heated.For example, if the temperature of the battery is extremely high and heating of the interior of the vehicle compartment 100 is requested, the vehicle-mounted temperature control device 1 is set to the state shown in Fig. 11. Furthermore, in the example shown in Fig. 12, the vehicle-mounted temperature control device 1 is in an operating state similar to the example shown in Fig. 10, except that the first control valve 28 is open. Therefore, in the example shown in Fig. 12, the refrigerant in the refrigeration circuit 2 flows to both the evaporator 26 and the refrigerant line 27a of the radiator 27. As a consequence, the refrigerant in the refrigeration circuit 2 absorbs heat from the surrounding air at the evaporator 26, absorbs heat from the cooling water in the low-temperature circuit 3 at the radiator 27, and releases heat to the cooling water of the high-temperature circuit 4 at the condenser 22. Due to the absorption of heat at the evaporator 26, the interior of the vehicle compartment 100 is cooled. The vehicle-mounted temperature control device 1 is, for example, based on the example shown in Fig.The operating condition shown in section 12 is set when the battery temperature is extremely high and cooling of the interior of the vehicle compartment 100 is required. Fig. 13 shows the operating state of the vehicle-mounted temperature control device 1 when the low-temperature circuit 3 is in a fourth mode. As can be seen from Fig. 13, in the fourth mode both the first pump 31 and the second pump 32 are in operation. Furthermore, the four-way valve 36 is fixed in the second state. Therefore, the first sub-circuit 3a and the second sub-circuit 3b are connected. Additionally, the first three-way valve 34 is fixed to the side of the first bypass flow path 3c, while the second three-way valve 35 is fixed to the side of the low-temperature radiator 33 (side of the second bypass flow path 3d). It should be noted that in the fourth mode, only one pump—either the first pump 31 or the second pump 32—can be in operation. As a consequence, if the operating state of the low-temperature circuit 3 is in the fourth mode, the coolant in the low-temperature circuit 3 circulates through the first pump 31, the coolant line 27b of the radiator 27, the low-temperature radiator 33, the second pump 32, and the PCU heat exchanger 38 in that order. In other words, the coolant in the low-temperature circuit 3 circulates without passing through the battery heat exchanger 37 and the engine heat exchanger 39. Therefore, the coolant in the low-temperature circuit 3 absorbs heat from the outside air at the low-temperature radiator 33, absorbs heat from the PCU at the PCU heat exchanger 38, and releases heat to the refrigerant of the refrigeration circuit 2 at the radiator 27. Furthermore, in the example shown in Fig. 13, the compressor 21 and the third pump 41 are in operation, just as in the example shown in Fig. 8. In addition, the first control valve 28 of the refrigeration circuit 2 is closed, and the second control valve 29 is open. Furthermore, the three-way valve 43 of the high-temperature circuit 4 is fixed to the side of the heating device flow path 4c. Therefore, the refrigerant in the refrigeration circuit 2 absorbs heat from the cooling water in the low-temperature circuit 3 at the radiator 27 and releases heat to the cooling water of the high-temperature circuit 4 at the condenser 22. Furthermore, the cooling water in the high-temperature circuit 4 absorbs heat from the refrigerant in the refrigeration circuit 2 at the condenser 22 and releases heat to the surrounding air at the heating device core 45. Due to this heat transfer, the interior of the vehicle compartment 100 is heated.The vehicle-mounted temperature control device 1 is, for example, set to the operating state shown in Fig. 13, when the temperature of the battery is low and heating of the interior of the vehicle compartment 100 is required and the temperature of the coolant in the low-temperature circuit 3 is not so low (if, for example, it is higher than -20°C). Control of the vehicle-mounted temperature control unit Figures 14 and 15 are flowcharts showing an example of a control routine for controlling the vehicle-mounted temperature control device 1. The control routine shown is executed at each specific time interval. As shown in Fig. 14, step S11 first determines whether the battery temperature Tb is higher than the reference battery temperature Tb1. The battery temperature Tb is measured by the battery temperature sensor 52. The reference battery temperature Tb1 is a temperature at which battery degradation etc. does not progress, but easily reaches a temperature at which battery degradation etc. will progress if the temperature exceeds this value, and is, for example, 30°C. If step S11 determines that the battery temperature Tb is higher than the reference battery temperature Tb1, the control routine proceeds to step S12. Step S12 determines whether the battery temperature Tb is higher than the upper limit battery temperature Tb2. The upper limit battery temperature Tb2 is a temperature above which the battery deteriorates. For example, it is 40°C. If step S12 determines that the battery temperature Tb is higher than the upper limit battery temperature Tb2, the control routine proceeds to step S13. At step S13, the operating state of the low-temperature circuit 3 is set to the third mode, as shown in Figs. 10, 11 to 12. Therefore, both the first pump 31 and the second pump 32 are in operation, and the four-way valve 36 is set to the first state. Consequently, if the battery temperature Tb is higher than the upper limit battery temperature Tb2, the connection state of the low-temperature circuit 3 is set to the first state. Furthermore, at step S13, the compressor 21 is operated, and the second control valve 29 is opened. Next, in step S14, it is determined whether the heating request has been set to ON. The ON / OFF state of the vehicle 100's heating request can, for example, be switched automatically based on the user's temperature setting, the temperature in the vehicle compartment, etc., or it can be switched directly by the user using a switch. If step S14 determines that the heating request is set to ON, the control routine proceeds to step S15. In step S15, the third pump 41 is operated and the first control valve 28 is closed. Furthermore, the three-way valve 43 is set to the side of the heating device flow path 4c, and the electric heating device 44 is set to OFF. As a result, the vehicle-mounted temperature control device 1 enters the operating state shown in Fig. 11. If, on the other hand, step S14 determines that the heating request is not set to ON, the control routine proceeds to step S16. Step S16 determines whether the cooling request is set to ON. The ON / OFF state of the vehicle 100's cooling request can, for example, be switched automatically based on the user's temperature setting, the temperature in the vehicle compartment, etc., or it can be switched directly by the user using a switch. If step S16 determines that the cooling request is set to ON, the control routine proceeds to step S17. In step S17, the third pump 41 is operated and the first control valve 28 is opened. Furthermore, the three-way valve 43 is set to the side of the radiator flow path 4b, and the electric heating device 44 is set to OFF. As a result, the vehicle-mounted temperature control device 1 enters an operating state as shown in Fig. 12. If, at step S16, it is determined that the cooling request is not set to ON, that is, if there is neither a heating nor a cooling request, the control routine proceeds to step S18. At step S18, the third pump 41 is operated and the first control valve 28 is closed. Furthermore, the three-way valve 43 is set to the side of the radiator flow path 4b, and the electric heating device 44 is set to OFF. As a result, the vehicle-mounted temperature control device 1 enters the operating state shown in Fig. 10. If step S12 determines that the battery temperature Tb is equal to or lower than the upper limit battery temperature Tb2, the control routine proceeds to step S19. Step S19 determines whether the temperature of the cooling water Tw in the low-temperature circuit 3, specifically the temperature of the cooling water Tw flowing into the PCU heat exchanger 38, is higher than the reference temperature Tw1. The temperature of the cooling water Tw in the low-temperature circuit 3 is measured by the first water temperature sensor 53. Furthermore, the reference temperature Tw1 is a temperature similar to the upper limit battery temperature Tb2 and is, for example, 40°C. If step S19 determines that the cooling water temperature Tw in the low-temperature circuit 3 is higher than the reference temperature Tw1, the control routine proceeds to step S13. Conversely, if step S19 determines that the cooling water temperature Tw in the low-temperature circuit 3 is equal to or lower than the reference temperature Tw1, the control routine proceeds to step S20. Step S20 determines whether the coolant temperature Tw in the low-temperature circuit 3 is higher than the battery temperature Tb. If it is determined that the coolant temperature Tw is higher than the battery temperature Tb, the control routine proceeds to step S21. Conversely, if it is determined that the coolant temperature Tw is equal to or lower than the battery temperature Tb, the control routine proceeds to step S31. In step S21, the operating state of the low-temperature circuit 3 is set to the second mode, as shown in Fig. 7, Fig. 8 to Fig. 9. Therefore, the first pump 31 and the second pump 32 are both in operation and the four-way valve 36 is set to the second state. In the present embodiment, this means that, in principle, if the battery temperature Tb is equal to or less than the upper limit battery temperature Tb2 and higher than the reference battery temperature Tb1, the operating state of the low-temperature circuit 3 is set to the second mode. Therefore, at this time, the connection state of the low-temperature circuit 3 is set to the second state, in which the battery heat exchanger 37 is connected to the cooler 27, the PCU heat exchanger 38, and the low-temperature radiator 33. In the present embodiment, however, even if the temperature Tb of the battery is equal to or less than the upper limit battery temperature Tb2 and higher than the reference battery temperature Tb1, if the temperature of the cooling water Tw in the low-temperature circuit 3 is higher than the reference temperature Tw1, the operating state of the low-temperature circuit 3 is set to the third mode, whereas if the temperature of the cooling water Tw in the low-temperature circuit 3 is higher than the temperature Tb of the battery, it is set to the first mode or the fourth mode. If, in step S21, the operating state of the low-temperature circuit 3 is set to the second mode, the next step in step S22 determines whether the heating request is set to ON. If, in step S22, it is determined that the heating request is set to ON, the control routine proceeds to step S23. In step S23, the compressor 21 and the third pump 41 are operated, the first control valve 28 is closed, and the second control valve 29 is opened. Furthermore, the three-way valve 43 is set to the side of the heating device flow path 4c, and the electric heating device 44 is set to OFF. As a result, the vehicle-mounted temperature control device 1 enters the operating state shown in Fig. 8. If, on the other hand, step S22 determines that the heating request is not set to ON, the control routine proceeds to step S24. Step S24 determines whether the cooling request has been set to ON. If step S24 determines that the cooling request is set to ON, the control routine proceeds to step S25. In step S25, the compressor 21 and the third pump 41 are operated, the first control valve 28 is opened, and the second control valve 29 is closed. Furthermore, the three-way valve 43 is set to the side of the radiator flow path 4b, and the electric heating device 44 is set to OFF. As a result, the vehicle-mounted temperature control device 1 enters an operating state as shown in Fig. 9. If step S24 determines that the cooling request is not set to ON, the control routine proceeds to step S26. In step S26, the compressor 21 and the third pump 41 are stopped, and the electric heating device 44 is set to OFF. As a consequence, the vehicle-mounted temperature control device 1 enters an operating state as shown in Fig. 7. If step S11 determines that the battery temperature Tb is equal to or lower than the reference battery temperature Tb1, the routine proceeds to step S31. Step S31 determines whether the heating requirement is set to ON. If step S31 determines that the heating requirement is set to ON, the control routine proceeds to step S32. In step S32, it is determined whether the temperature of the cooling water Tw in the low-temperature circuit 3, as detected by the first water temperature sensor 53, is lower than the lower limit temperature Tw0. The lower limit temperature Tw0 is a cooling water temperature below which the refrigeration circuit can no longer be adequately implemented in refrigeration circuit 2 and is, for example, -20°C. Furthermore, in step S33, it is determined whether the temperature of the cooling water Tw in the low-temperature circuit 3, as measured by the first water temperature sensor 53, is higher than the upper limit temperature Tw2. The upper limit temperature Tw2 is the temperature of the cooling water above which the PCU can no longer be adequately cooled. For example, it is 50°C. Furthermore, step S34 determines whether the temperature To of the oil with which the engine heat exchanger 39 exchanges heat is higher than the upper limit temperature To1. The upper limit temperature To1 is the oil temperature above which the engine cannot be adequately cooled. For example, it is 80°C. If, at step S32, it is determined that the temperature of the cooling water Tw in the low-temperature circuit 3 is lower than the lower limit temperature Tw0, if, at step S33, it is determined that the temperature of the cooling water Tw in the low-temperature circuit 3 is higher than the upper limit temperature Tw2, or if, at S34, it is determined that the temperature To of the oil is higher than the upper limit temperature To1, the routine proceeds to step S35. At step S35, the operating state of the low-temperature circuit 3 is set to the first mode, as shown in Figs. 4, 5 to 6. Therefore, the first pump 31 is stopped and the second pump 32 is operated. Furthermore, the four-way valve 36 is set to the first state. Additionally, at step S35, the compressor 21 is stopped, the third pump 41 is operated, the three-way valve 43 is set to the side of the heating flow path 4c, and the electric heating device 44 is set to ON. As a result, the vehicle-mounted temperature control device 1 enters the operating state shown in Fig. 5. If, on the other hand, step S32 determines that the temperature of the cooling water Tw in the low-temperature circuit 3 is equal to or greater than the lower limit temperature Tw0, if step S33 determines that the temperature of the cooling water Tw in the low-temperature circuit 3 is equal to or less than the upper limit temperature Tw2, and if step S34 determines that the temperature To of the oil is equal to or less than the upper limit temperature To1, the routine proceeds to step S36. At step S36, the operating state of the low-temperature circuit 3 is set to the fourth mode, as shown in Fig. 13. Therefore, the first pump 31 and the second pump 32 are operated together, and the four-way valve 36 is set to the second state. Furthermore, at step S36, the compressor 21 and the third pump 41 are operated, the first control valve 28 is closed, and the second control valve 29 is opened. Additionally, the three-way valve 43 is set to the side of the heating device flow path 4c, while the electric heating device 44 is set to OFF. As a result, the vehicle-mounted temperature control device 1 enters the operating state shown in Fig. 13. In the present embodiment, this means that if the heating requirement is set to ON and the temperature of the cooling water Tw in the low-temperature circuit 3 is lower than the lower limit temperature Tw0, the operating state of the low-temperature circuit 3 is set to the first mode. Therefore, at this time, the connection state of the low-temperature circuit 3 is also set to the first state. Furthermore, in the present embodiment, if the heating requirement is set to ON and the temperature of the cooling water Tw in the low-temperature circuit 3 is equal to or greater than the lower limit temperature Tw0, the operating state of the low-temperature circuit 3 is set to the fourth mode. Therefore, at this time, the connection state of the low-temperature circuit 3 is set to the second state, in which the battery heat exchanger 37 is not connected to the cooler 27, the PCU heat exchanger 38, and the low-temperature radiator 33. It should be noted that in the present embodiment, if the heating requirement is set to ON, even if the temperature of the cooling water Tw in the low-temperature circuit 3 is equal to or greater than the lower limit temperature Tw0, if the temperature of the cooling water Tw in the low-temperature circuit 3 is higher than the upper limit temperature Tw2, or if the temperature To of the oil is higher than the upper limit temperature To1, the operating state of the low-temperature circuit 3 is set to the first mode. If step S31 determines that the heating request is not set to ON, the control routine proceeds to step S37. In step S37, the operating state of the low-temperature circuit 3 is set to the first mode, as shown in Figures 4, 5 to 6. Therefore, if the battery temperature is equal to or less than the reference battery temperature and heating inside the vehicle compartment 100 is not requested, the connection state of the low-temperature circuit 3 is set to the first state. Next, in step S38, it is determined whether the cooling request is set to ON. If step S38 determines that the cooling request is set to ON, the control routine proceeds to step S39. In step S39, the compressor 21 and the third pump 41 are both operated, the first control valve 28 is opened, and the second control valve 29 is closed. Furthermore, the three-way valve 43 is set to the side of the radiator flow path 4b, and the electric heating device 44 is set to OFF. As a result, the vehicle-mounted temperature control device 1 enters an operating state as shown in Fig. 6. If step S38 determines that the cooling request is not set to ON, the control routine proceeds to step S40. In step S40, the compressor 21 and the third pump 41 are stopped, and the electric heating device 44 is set to OFF. As a result, the vehicle-mounted temperature control device 1 enters an operating state as shown in Fig. 4. Mode of action and effect In the present embodiment, in the low-temperature circuit 3, in all modes from the first mode to the fourth mode, the cooling water in the low-temperature circuit 3 flows through the PCU heat exchanger 38. Because of this, even if the amount of heat generated by the PCU temporarily increases due to rapid acceleration, etc., the elements of the PCU are prevented from exceeding the thermal resistance temperature. Furthermore, in the present embodiment, if the operating state of the low-temperature circuit 3 is in the first mode up to the third mode, the cooling water of the low-temperature circuit 3 circulates through the PCU heat exchanger 38 and the low-temperature radiator 33. Because of this, it is possible to absorb heat from the PCU and release this heat at the low-temperature radiator 33. Furthermore, in the present embodiment, if the operating state of the low-temperature circuit 3 is in the first mode up to the third mode, the cooling water of the low-temperature circuit 3 circulates through the engine heat exchanger 39 and the low-temperature radiator 33. As a result, it is possible to absorb heat from the MG and release this heat at the low-temperature radiator 33. Furthermore, in the present embodiment, if the operating state of the low-temperature circuit 3 is in the second and third modes, the cooling water of the low-temperature circuit 3 can circulate through the battery heat exchanger 37 and the low-temperature radiator 33. As a result, it is possible to absorb heat from the battery and release this heat at the low-temperature radiator 33. Furthermore, in the present embodiment, if the operating state of the low-temperature circuit 3 is in the second mode and the cooling water of the low-temperature circuit 3 absorbs heat at the low-temperature radiator 33 and releases heat at the battery heat exchanger 37, the cooling water flows through the low-temperature radiator 33, the battery heat exchanger 37 and the engine heat exchanger 39 in this order and circulates through them. As a result, the coolant, which has been cooled at the low-temperature radiator 33, flows into the battery heat exchanger 37 before the temperature of the coolant is increased by the engine heat exchanger 39 with its large amount of heat output, and therefore it is possible to cool the battery efficiently. Furthermore, in the present embodiment, if the operating state of the low-temperature circuit 3 is in the third mode, the cooling water of the low-temperature circuit 3, which has been cooled by the radiator 27, flows through the battery heat exchanger 37. As a result, if the battery reaches a high temperature, it can be cooled quickly. Furthermore, in the present embodiment, if the operating state of the low-temperature circuit 3 is the fourth mode, the cooling water of the low-temperature circuit 3 can circulate through the low-temperature radiator 33 and the cooling water line 27b of the radiator 27. As a result, while the interior of the vehicle compartment 100 is being heated, heat absorbed from the outside air by the low-temperature radiator 33 can be used for heating. Furthermore, in the present embodiment, if the operating state of the low-temperature circuit 3 is in the fourth mode, the cooling water, which has been cooled by passing through the cooling water line 27b of the radiator 27, does not flow through the engine heat exchanger 39. This prevents the oil in the engine heat exchanger 39 from being excessively cooled and thus prevents increased friction. Preferred embodiments of the present invention have been explained above, but the present invention is not limited to these embodiments and can be modified and amended in various ways within the scope of the claims. For example, in the preceding embodiment, if in step S33 of Fig. 15 it is determined that the temperature of the coolant Tw in the low-temperature circuit 3 is higher than the upper limit temperature Tw2, or if in step S34 it is determined that the temperature To of the oil is higher than the upper limit temperature To1, the operating state of the low-temperature circuit 3 is set to the first mode and the electric heating device 44 is set to ON. Therefore, the vehicle-mounted temperature control device 1 enters the operating state as shown in Fig. 5. In this case, however, the vehicle-mounted temperature control device 1 can also enter the operating state shown in Fig. 8. Provided, however, that the battery does not need to be cooled in this case, the first three-way valve 34 is therefore fixed to the side of the first bypass flow path 3c. Consequently, if the temperature of the coolant in the low-temperature circuit 3 is extremely high, or if the temperature of the oil in the engine heat exchanger 39 is extremely high, the cooler 27 can be used to rapidly cool the coolant or the oil. REFERENCE MARK LIST 1 Vehicle-mounted temperature control unit 2 Refrigeration circuit 3 Low-temperature circuit 4 High-temperature circuit 5 Control device 6 Air passage 22 Condenser 27 Radiator 33 Low-temperature radiator 34 First three-way valve 35 Second three-way valve 36 Four-way valve 37 Battery heat exchanger 38 PCU heat exchanger 39 Engine heat exchanger

Claims

Vehicle-mounted temperature control device (1) used in a vehicle, the vehicle having an engine for propelling the vehicle, a battery supplying electrical power to the engine, and a power control unit (PCU) controlling the electrical power supplied to the engine, the vehicle-mounted temperature control device (1) comprising: a first heating circuit (3) having a battery heat exchanger (37) exchanging heat with the battery, a PCU heat exchanger (38) exchanging heat with the power control unit (PCU), a radiator (33), and a first heat exchanger (27) configured such that the first heating medium circulates through these; and a refrigeration circuit (2) having a second heat exchanger (22) that transfers heat from a refrigerant to something other than the refrigerant and the first heating medium to cause the refrigerant to condense.and has the first heat exchanger (27) which absorbs heat from the first heat medium to the refrigerant in order to cause the refrigerant to evaporate, and which is designed to realize a refrigeration circuit through the refrigerant circulating through it, wherein the first heat circuit (3) is designed to be able to switch between connection states of a first state in which the battery heat exchanger (37) and the first heat exchanger (27) are connected such that the first heat medium flows through them, the PCU heat exchanger (38) and the radiator (33) are connected such that the first heat medium flows through them, and the battery heat exchanger (37) and the first heat exchanger (27) are not connected to the PCU heat exchanger (38) and the radiator (33) in a state in which the first heat medium flows through them, and a second state in which the first heat exchanger (27), the PCU heat exchanger (38) and the radiator (33) are connected in such a way,that the first heat medium flows through these, characterized in that if a temperature of the battery is higher than the reference battery temperature, a connection state of the first heat circuit (3) is set to the second state and a state is set in which the battery heat exchanger (37) is not connected to the first heat exchanger (27), the PCU heat exchanger (38) and the radiator (33) in such a way that the first heat medium flows through them. Vehicle-mounted temperature control device (1) according to claim 1, further comprising an engine heat exchanger (39) which exchanges heat with the engine, wherein in the first state, the engine heat exchanger (39) is connected to the PCU heat exchanger (38) and the radiator (33) in such a way that the first heat medium flows through them, and the battery heat exchanger (37) and the first heat exchanger (27) are not connected to the PCU heat exchanger (38), the radiator (33) and the engine heat exchanger (39) in a state in which the first heat medium flows through them. Vehicle-mounted temperature control device (1) according to claim 2, wherein the first heat circuit (3) is designed to switch between connection states in which, in the second state, the engine heat exchanger (39) is connected to the first heat exchanger (27), the PCU heat exchanger (38) and the radiator (33) such that the first heat medium flows through it, and a state in which the engine heat exchanger (39) is not connected to the first heat exchanger (27), the PCU heat exchanger (38) and the radiator (33) such that the first heat medium flows through it. Vehicle-mounted temperature control device (1) according to claim 3, wherein the first heat circuit (3) is designed such that, in the second state and in a state in which the engine heat exchanger (39) is connected to the first heat exchanger (27), the PCU heat exchanger (38) and the radiator (33) in such a way that the first heat medium flows through them, the first heat medium circulates through the radiator (33), the PCU heat exchanger (38) and the engine heat exchanger (39) in this order. Vehicle-mounted temperature control device (1) according to one of claims 2 to 4, wherein the first heat circuit (3) is designed such that, in the first state, the first heat medium circulates through the radiator (33), the PCU heat exchanger (38) and the engine heat exchanger (39) in that order. Vehicle-mounted temperature control device (1) according to one of claims 1 to 5, wherein the first heat circuit (3) is designed to be able to switch between connection states, in the second state, between a state in which the battery heat exchanger (37) is connected to the first heat exchanger (27), the PCU heat exchanger (38) and the radiator (33) in such a way that the first heat medium flows through them, and a state in which the battery heat exchanger (37) is not connected to the first heat exchanger (27), the PCU heat exchanger (38) and the radiator (33) in such a way that the first heat medium flows through them. Vehicle-mounted temperature control device (1) according to any one of claims 1 to 6, wherein, when a temperature of the battery is higher than an upper limit battery temperature which is higher than the reference battery temperature, the connection state of the first thermal circuit (3) is set to the first state. Vehicle-mounted temperature control device (1) according to any one of claims 1 to 7, wherein, when the temperature of the battery is equal to or less than the reference battery temperature and heating inside the vehicle compartment is not required, the connection state of the first heat circuit (3) is set to the first state. Vehicle-mounted temperature control device (1) according to any one of claims 1 to 8, wherein, when the temperature of the battery is equal to or less than the reference battery temperature and heating is requested inside the compartment of the vehicle and the temperature of the first heat medium is lower than a predetermined lower limit heat medium temperature, the connection state of the first heat circuit (3) is set to the first state. Vehicle-mounted temperature control device (1) according to claim 9, wherein, when the temperature of the battery is equal to or less than the reference battery temperature and heating is requested inside the vehicle compartment and the temperature of the first heat medium is equal to or greater than the lower limit heat medium temperature, the connection state of the first heat circuit (3) is set to the state in which the battery heat exchanger (37) is not connected to the first heat exchanger (27), the PCU heat exchanger (38) and the radiator (33). Vehicle-mounted temperature control device (1) according to one of claims 1 to 10, further comprising a second heat circuit (4) which has a heating device core (45) which heats the interior of a vehicle compartment and is designed such that the second heat medium circulates through the heating device core (45), wherein the second heat exchanger (22) exchanges heat between the refrigerant and the second heat medium in order to cause heat to move from the refrigerant to the second heat medium.

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