Temperature control system and temperature control system control method

Abstract

A temperature control system and a method for controlling a temperature control system are provided that can quickly start up a specific mode by configuring and controlling a refrigerant circuit. [Solution] The system includes a refrigerant circuit (10) through which refrigerant RF circulates, a heat medium circuit (20) through which a heat medium HM that exchanges heat with the refrigerant RF circulates, and a control unit (40). The heat medium circuit (20) has an indoor air conditioning unit (23) that heats an object to be temperature-controlled using the heat medium HM. The control unit (40) mixes the heat medium HM flowing out of the condenser (12) with the heat medium HM flowing out of the evaporator (14), causes the mixed heat medium HM to flow into the condenser (12) and the evaporator (14), and also causes the heat medium HM flowing out of the condenser (12) to flow into the indoor air conditioning unit (23), and controls the expansion valve (13) by determining whether the refrigerant RF flowing out of the condenser (12) is in a gas-liquid two-phase state or a liquid phase.

Description

[Technical Field]

[0001] The present disclosure relates to a temperature adjustment system and a method for controlling a temperature adjustment system. [Background technology]

[0002] BACKGROUND ART Conventionally, a vehicle thermal management system is known that has an operation mode in which a device to be heated is heated early when the outside air temperature is low (for example, Patent Document 1). The vehicle thermal management system disclosed in Patent Document 1 can execute an operation mode (third operation mode) in which a coolant circuit is formed by a pump, a coolant cooler, a coolant heater, and an equipment to be heated.

[0003] In the third operating mode of Patent Document 1, when supplying heat medium to the equipment to be heated, the heat medium discharged from the pump is branched by the first switching valve into three systems: the low-pressure side heat exchanger, the high-pressure side heat exchanger, and the equipment to be heated, and supplied to each system.The three systems are then merged into one by the second switching valve, and then directed back to the pump. It is said that by implementing this operating mode, the equipment to be heated can be heated quickly when the outside temperature is low. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-201148 Summary of the Invention [Problem to be solved by the invention]

[0005] The vehicle thermal management system of Patent Document 1 aims to heat the equipment to be heated early by making efforts to configure and control the coolant circuit, but does not particularly consider the configuration and control of the refrigerant circuit.

[0006] The present disclosure has been made in consideration of the above circumstances, and aims to provide a temperature control system and a control method for a temperature control system that can quickly start up a specific mode by configuring and controlling the refrigerant circuit. [Means for solving the problem]

[0007] In order to solve the above problems, the temperature adjustment system and the control method for the temperature adjustment system of the present disclosure employ the following means.

[0008] A temperature control system according to one aspect of the present disclosure includes a refrigerant circuit having a compressor, a high-pressure side heat exchanger, a pressure reduction unit, and a low-pressure side heat exchanger, and through which a refrigerant circulates; a heat medium circuit through which a heat medium circulates that exchanges heat with the refrigerant in the high-pressure side heat exchanger and the low-pressure side heat exchanger; and a control unit, wherein the heat medium circuit has a temperature control device that heats a temperature control target using the heat medium, and the control unit mixes the heat medium flowing out of the high-pressure side heat exchanger with the heat medium flowing out of the low-pressure side heat exchanger, causes the mixed heat medium to flow into the high-pressure side heat exchanger and the low-pressure side heat exchanger, and controls the pressure reduction unit to determine whether the refrigerant flowing out of the high-pressure side heat exchanger is in a gas-liquid two-phase state or a liquid phase.

[0009] A control method for a temperature adjustment system according to one aspect of the present disclosure includes a refrigerant circuit having a compressor, a high-pressure side heat exchanger, a pressure reduction unit, and a low-pressure side heat exchanger, and through which a refrigerant circulates, and a heat medium circuit through which a heat medium that exchanges heat with the refrigerant in the high-pressure side heat exchanger and the low-pressure side heat exchanger circulates, the heat medium circuit having a temperature adjustment device that heats a temperature adjustment target using the heat medium, the control method comprising: a heater mode in which the heat medium flowing out of the high-pressure side heat exchanger is mixed with the heat medium flowing out of the low-pressure side heat exchanger, the mixed heat medium is caused to flow into the high-pressure side heat exchanger and the low-pressure side heat exchanger, and the heat medium flowing out of the high-pressure side heat exchanger is caused to flow into the temperature adjustment device; and the pressure reduction unit is adjusted to determine whether the refrigerant flowing out of the high-pressure side heat exchanger is in a gas-liquid two-phase state or a liquid phase. [Effects of the Invention]

[0010] According to the present disclosure, a specific mode can be started early by configuring and controlling the refrigerant circuit. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic configuration diagram showing a temperature adjustment system (when a heater mode is executed) according to a first embodiment of the present disclosure. [Figure 2] This is a Mollier diagram (ph diagram) of the refrigerant circuit when the heater mode is running. [Figure 3] FIG. 10 is a schematic configuration diagram showing a temperature adjustment system (in heater mode) according to a modified example of the first embodiment of the present disclosure. [Figure 4] FIG. 10 is a schematic configuration diagram showing a temperature adjustment system (when a heater mode is executed) according to a second embodiment of the present disclosure. [Figure 5] FIG. 10 is a schematic configuration diagram showing a temperature adjustment system (in heater mode) according to a first modified example of the second embodiment of the present disclosure. [Figure 6] FIG. 10 is a schematic configuration diagram showing a temperature adjustment system (in heater mode) according to Modification 2 of the second embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, a temperature regulation system and a control method for a temperature regulation system according to a first embodiment and a second embodiment of the present disclosure will be described with reference to the drawings. In the following description, the names of the pipes may be distinguished from one another, but this does not necessarily mean that each pipe is a separate pipe. Conversely, separate pipes may be combined to form a pipe with the same name.

[0013] [First embodiment] The temperature control system 1 is a system that is installed in a vehicle (not shown). Examples of vehicles include electric vehicles that do not have an engine and obtain driving force for running from an electric motor, and so-called hybrid vehicles that obtain driving force for running from an engine and / or an electric motor.

[0014] The temperature control system 1 is responsible for air conditioning such as heating and cooling, dehumidification, and ventilation of the passenger compartment, as well as thermal management and / or exhaust heat recovery of on-board devices such as the battery device (power supply device), traction motor, and heat-generating electronic devices installed in the vehicle. Conditioning the air to an appropriate temperature and humidity and maintaining on-board devices at an appropriate temperature are collectively referred to as "thermal management."

[0015] Electric power stored in a battery device is supplied to the temperature adjustment system 1 and the electrically powered devices and electronic devices provided in the on-board device. The battery device is charged from an external power source, for example, when the vehicle is stopped.

[0016] The temperature adjustment system 1 includes a refrigerant circuit 10 configured to circulate a refrigerant RF, a heat medium circuit 20 configured to circulate a heat medium HM that exchanges heat with the refrigerant RF, and a control unit 40 that controls the electric devices and electronic devices provided in each circuit. The temperature control system 1 includes sensors (not shown) for acquiring information necessary for control (e.g., temperature and pressure), such as a sensor for detecting the outside air temperature, a sensor for detecting the temperature of the conditioned air blown into the vehicle cabin, a sensor for detecting the temperature of the vehicle cabin, a sensor for detecting the temperature of the refrigerant RF, a sensor for detecting the temperature of the heat medium HM, and a sensor for detecting the pressure of the refrigerant RF.

[0017] The temperature adjustment system 1 can execute an operation mode selected by the occupant or the control unit 40. Examples of operation modes of the temperature adjustment system 1 according to this embodiment include a heater mode and a heat pump mode (not shown).

[0018] <Refrigerant circuit configuration> As shown in FIG. 1, the refrigerant circuit 10 includes a compressor 11 that compresses the refrigerant RF, a condenser (high-pressure side heat exchanger) 12 that condenses the refrigerant RF, an expansion valve (pressure reduction section) 13 that reduces the pressure of the refrigerant RF, an evaporator (low-pressure side heat exchanger) 14 that evaporates the refrigerant RF, and a plurality of pipes that connect the various devices. A refrigerant RF is sealed in the refrigerant circuit 10. The sealed refrigerant RF circulates in the refrigerant circuit 10 according to a known refrigeration cycle.

[0019] The refrigerant RF may be a single refrigerant or a mixed refrigerant. For example, the refrigerant RF may be an HFC (hydrofluorocarbon) refrigerant such as R410A or R32, an HFO (hydrofluoroolefin) refrigerant such as R1234ze or R1234yf, or a hydrocarbon (HC) refrigerant such as propane or isobutane. In particular, it is preferable to use propane as the refrigerant RF in this embodiment.

[0020] When the fluorocarbon-based or hydrocarbon-based refrigerant RF is used as an example, the refrigerant circuit 10 forms a subcritical refrigeration cycle in which the refrigerant pressure on the high-pressure side does not exceed the critical pressure of the refrigerant RF. When carbon dioxide (CO2) is used as the refrigerant RF, the refrigerant circuit 10 forms a transcritical refrigeration cycle in which the refrigerant pressure on the high-pressure side exceeds the critical pressure of the refrigerant RF. Even in this case, the refrigerant RF dissipates heat through the high-pressure side heat exchanger, as in the condenser 12 of this embodiment, and the refrigerant RF absorbs heat through the low-pressure side heat exchanger, as in the evaporator 14 of this embodiment.

[0021] The compressor 11 is a device that compresses the refrigerant RF guided from the evaporator 14. The compressor 11 is, for example, an electric compressor equipped with an electric motor (not shown). The rotation speed of the compressor 11 is controlled by the control unit 40. The compressor 11 is exemplified by a scroll compressor and a rotary compressor.

[0022] A refrigerant outlet (discharge port) of the compressor 11 is connected to one end of a compressor refrigerant pipe L11. The other end of the compressor refrigerant pipe L11 is connected to a refrigerant inlet of the condenser 12. That is, the compressor refrigerant pipe L11 is a pipe that connects the discharge port of the compressor 11 and the refrigerant inlet of the condenser 12.

[0023] The condenser 12 is a heat exchanger that exchanges heat between the refrigerant RF guided from the compressor 11 via the compressor refrigerant pipe L11 and the heat medium HM flowing through the heat medium circuit 20.

[0024] The refrigerant outlet of the condenser 12 is connected to one end of a condenser refrigerant pipe L12. The other end of the condenser refrigerant pipe L12 is connected to the refrigerant inlet of the expansion valve 13. That is, the condenser refrigerant pipe L12 is a pipe that connects the refrigerant outlet of the condenser 12 and the refrigerant inlet of the expansion valve 13.

[0025] The expansion valve 13 is a device that reduces the pressure of the refrigerant RF guided from the condenser 12 via the condenser refrigerant pipe L12 and adjusts the flow rate of the refrigerant RF. The expansion valve 13 is exemplified by an electronic expansion valve whose opening is controlled based on a command from the control unit 40 .

[0026] The state of the refrigerant RF flowing out from the condenser 12 can be changed by adjusting the aperture of the expansion valve 13. For example, the refrigerant RF flowing out from the condenser 12 can be made into a liquid phase or a two-phase gas-liquid phase by adjusting the aperture of the expansion valve 13. Furthermore, when the refrigerant RF is made into a two-phase gas-liquid phase, the wetness (dryness) of the refrigerant RF can also be changed by adjusting the aperture of the expansion valve 13.

[0027] A refrigerant outlet of the expansion valve 13 is connected to one end of an expansion valve refrigerant pipe L13. The other end of the expansion valve refrigerant pipe L13 is connected to the refrigerant inlet of the evaporator 14. That is, the expansion valve refrigerant pipe L13 is a pipe that connects the refrigerant outlet of the expansion valve 13 and the refrigerant inlet of the evaporator 14.

[0028] The evaporator 14 is a device that exchanges heat between the refrigerant RF guided from the expansion valve 13 via the expansion valve refrigerant pipe L13 and the heat medium HM flowing through the heat medium circuit 20.

[0029] The refrigerant outlet of the evaporator 14 is connected to one end of an evaporator refrigerant pipe L14. The other end of the evaporator refrigerant pipe L14 is connected to the refrigerant inlet (suction port) of the compressor 11. That is, the evaporator refrigerant pipe L14 is a pipe that connects the refrigerant outlet of the evaporator 14 and the suction port of the compressor 11.

[0030] An accumulator (gas-liquid separator) (not shown) is provided in the evaporator refrigerant pipe L14 (between the evaporator 14 and the compressor 11). This prevents the liquid refrigerant from being sent to the compressor 11.

[0031] The compressor 11, the condenser 12, the expansion valve 13, the evaporator 14, and the refrigerant pipes connecting these devices to each other are installed, for example, outside the passenger compartment.

[0032] <Configuration of the heat medium circuit> The heat medium circuit 20 is configured so that the heat medium HM that exchanges heat with the refrigerant RF in the condenser 12 and the evaporator 14 of the refrigerant circuit 10 can circulate. The heat medium HM is used to heat or cool at least one temperature control target. In this embodiment, the temperature control target is, for example, air that is supplied to the vehicle interior and used for air conditioning. The temperature control target may also be an on-board battery device.

[0033] The heat medium circuit 20 includes a pump 21 that pressurizes the heat medium HM, an indoor air conditioning unit (temperature control device) 23, a branch valve 24 that branches one flow path into multiple flow paths, and multiple pipes that connect each device. A heat medium HM is sealed in the heat medium circuit 20. The sealed heat medium HM circulates in the heat medium circuit 20 according to a cycle (heat medium loop) that corresponds to the operation mode.

[0034] The heat medium HM sealed in the heat medium circuit 20 is a liquid such as water or brine that is maintained in a liquid phase and circulates through the heat medium circuit 20. Examples of brine include a mixed liquid of water and propylene glycol and a mixed liquid of water and ethylene glycol.

[0035] The pump 21 is a device that pumps the heat medium HM in a series of heat medium loops according to the operation mode. The rotation speed of the pump 21 is controlled by the control unit 40 .

[0036] A heat medium outlet (discharge port) of the pump 21 is connected to one end of a pump outlet pipe L21. The other end of the pump outlet pipe L21 is connected to the heat medium inlet of the indoor air conditioning unit 23. That is, the pump outlet pipe L21 is a pipe that connects the discharge port of the pump 21 and the heat medium inlet of the indoor air conditioning unit 23.

[0037] The interior air conditioning unit 23 is a unit configured to supply conditioned air to the vehicle cabin by exchanging heat between air sent by a fan (not shown) and the heat medium HM guided from the pump 21 via the pump outlet piping L21. The rotation speed of the fan (not shown) is controlled by the control unit 40.

[0038] A heat medium outlet of the indoor air conditioning unit 23 is connected to one end of a temperature adjustment device outlet pipe L22. The other end of the temperature adjustment device outlet pipe L22 is connected to the heat medium inlet (inlet 24i) of the branch valve 24. That is, the temperature adjustment equipment outlet pipe L22 is a pipe that connects the heat medium outlet of the indoor air conditioning unit 23 and the inlet 24i of the branch valve 24.

[0039] The branch valve 24 is a three-way valve, and has one inlet 24i and two outlets (heat medium outlets) 24o1 and 24o2. The branch valve 24 is a valve that distributes the heat medium HM, which is introduced from the indoor air conditioning unit 23 via the temperature adjustment equipment outlet pipe L22 and flows in from the inlet 24i, to the outlets 24o1 and 24o2 in an arbitrary ratio. The branch valve 24 is controlled by the control unit 40 to adjust the ratio of the flow rates of the heat medium HM introduced to the outlets 24o1 and 24o2. In other words, the ratio of the flow rate of the heat medium HM introduced to the condenser 12 and the flow rate of the heat medium HM introduced to the evaporator 14 is adjusted.

[0040] The outlet 24o1 of the branch valve 24 is connected to one end of a condenser inlet pipe L23. The other end of the condenser inlet pipe L23 is connected to the heat medium inlet of the condenser 12. That is, the condenser inlet pipe L23 is a pipe that connects the outlet 24o1 of the branch valve 24 and the heat medium inlet of the condenser 12.

[0041] An outlet 24o2 of the branch valve 24 is connected to one end of an evaporator inlet pipe L24. The other end of the evaporator inlet pipe L24 is connected to the heat medium inlet of the evaporator 14. That is, the evaporator inlet pipe L24 is a pipe that connects the outlet 24o2 of the branch valve 24 and the heat medium inlet of the evaporator 14.

[0042] The condenser 12 is a heat exchanger that exchanges heat between the heat medium HM introduced from the branch valve 24 via the condenser inlet pipe L23 and the refrigerant RF flowing through the refrigerant circuit 10.

[0043] The heat medium outlet of the condenser 12 is connected to one end of a condenser outlet pipe L25. The other end of the condenser outlet pipe L25 is connected to the other end of the evaporator outlet pipe L26, which will be described later. That is, the condenser outlet pipe L25 is a pipe that connects the heat medium outlet of the condenser 12 and the other end of the evaporator outlet pipe L26.

[0044] The evaporator 14 is a heat exchanger that exchanges heat between the heat medium HM introduced from the branch valve 24 via the evaporator inlet pipe L24 and the refrigerant RF flowing through the refrigerant circuit 10.

[0045] The heat medium outlet of the evaporator 14 is connected to one end of an evaporator outlet pipe L26. The other end of the evaporator outlet pipe L26 is connected to the other end of the condenser outlet pipe L25. That is, the evaporator outlet pipe L26 is a pipe that connects the heat medium outlet of the evaporator 14 and the other end of the condenser outlet pipe L25.

[0046] The portion where the condenser outlet pipe L25 and the evaporator outlet pipe L26 are connected is defined as a "junction C." In other words, the condenser outlet pipe L25 and the evaporator outlet pipe L26 join together at the junction C.

[0047] To the confluence C, one end of a pump inlet pipe L27 is connected. The other end of the pump inlet pipe L27 is connected to the heat medium inlet (suction port) of the pump 21. That is, the pump inlet pipe L27 is a pipe that connects the confluence C and the suction port of the pump 21.

[0048] <Controller configuration> The control unit 40 is a device that controls the electric devices and electronic devices provided in each circuit. The control unit 40 is composed of, for example, a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and a computer-readable storage medium. A series of processes for realizing various functions is stored in a storage medium, for example, in the form of a program. The CPU reads this program into RAM and executes information processing and arithmetic operations to realize various functions. The program may be pre-installed in a ROM or other storage medium, provided in a state stored in a computer-readable storage medium, or distributed via wired or wireless communication means. Examples of computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, and semiconductor memories.

[0049] <Refrigerant and heat transfer medium flow during steady-state operation in heater mode> The heater mode is suitable for heating when the outside air temperature is low and heat cannot be absorbed from the outside air into the heat medium HM. In the heater mode, the heat medium HM is used to transfer an amount of heat corresponding to the power of the compressor 11 as a heat source to the vehicle compartment (indoor air conditioning unit 23) while avoiding heat radiation from the heat medium HM to the outside air. That is, in the heater mode, the heat medium HM flowing out of the evaporator 14 circulates through the heat medium circuit 20 without being guided to an exterior heat exchanger (a heat exchanger that exchanges heat between the heat medium and the outside air), not shown. This ensures heating capacity even when the outside air temperature is significantly below 0°C.

[0050] A high-temperature, high-pressure refrigerant RF compressed by the compressor 11 is supplied to the condenser 12. In the condenser 12, the refrigerant RF exchanges heat with the heat medium HM to release heat, and the refrigerant RF is condensed and liquefied (may be supercooled). The liquefied high-pressure refrigerant RF is decompressed by the expansion valve 13 and then supplied to the evaporator 14. In the evaporator 14, the refrigerant RF exchanges heat with the heat medium HM to obtain latent heat of evaporation and evaporate, becoming a low-pressure gaseous refrigerant RF. The gasified refrigerant RF is sucked into the compressor 11. This cycle is then repeated.

[0051] The heat medium HM heated by the refrigerant RF in the condenser 12 is guided to the confluence C via the condenser outlet pipe L25. On the other hand, the heat medium HM cooled by the refrigerant RF in the evaporator 14 is guided to the confluence C via the evaporator outlet pipe L26. The heat medium HM guided to the confluence C is guided to the indoor air conditioning unit 23 via the pump inlet pipe L27 (and the pump 21) and the pump outlet pipe L21. The heat medium HM guided to the interior air conditioning unit 23 provides heat to the air in the vehicle interior, for example, to perform heating. The heat medium HM cooled by providing heat is led to the branch valve 24 via the temperature adjustment device outlet pipe L22. The heat medium HM introduced to the branch valve 24 is distributed at an arbitrary ratio to the condenser inlet pipe L23 and the evaporator inlet pipe L24. The heat medium HM introduced to the condenser 12 absorbs heat from the refrigerant RF flowing through the condenser 12 to liquefy the refrigerant RF. On the other hand, the heat medium HM introduced to the evaporator 14 imparts latent heat of evaporation to the refrigerant RF flowing through the evaporator 14 to evaporate the refrigerant RF.

[0052] The flow of the heat medium HM described above is generated by the pump 21 and the branch valve 24. As long as the flow of the heat medium HM described above can be generated, the positions of the pump 21 and the various valves are not particularly limited.

[0053] <Flow of refrigerant and heat medium when starting up heater mode> As shown in FIG. 2, when starting up the heater mode, the control unit 40 controls the expansion valve 13 so that the refrigerant RF flowing out of the condenser 12 is in a gas-liquid two-phase state rather than a liquid phase. The state of the refrigerant RF flowing out from the evaporator 14 is controlled by adjusting the opening degree of the expansion valve 13, as described above. The state of the refrigerant RF flowing out from the condenser 12 is linked to a map based on the opening degree of the expansion valve 13 and the rotation speed of the compressor 11. Therefore, if the target state of the refrigerant RF and the rotation speed of the compressor 11 are known, the opening degree of the expansion valve 13 can be uniquely determined. Usually, the rotation speed of the compressor 11 can be obtained. Therefore, by setting the target state of the refrigerant RF, the target opening degree of the expansion valve 13 can be uniquely determined from the map. The control unit 40 executes the processing and calculations required to determine the opening degree of the expansion valve 13 using the map, such as reading the map, setting the target state of the refrigerant RF, and obtaining the rotation speed of the compressor 11.

[0054] Alternatively, the heat exchange amount of the heat medium HM in the condenser 12 and / or the evaporator 14 and the circulation amount of the refrigerant RF may be estimated, and an enthalpy difference of the refrigerant in the condenser 12 and / or the evaporator 14 may be estimated based on the estimated heat exchange amount and the refrigerant circulation amount. The state of the refrigerant RF flowing out from the condenser 12 may be estimated based on the refrigerant state at the inlet of the condenser 12 and / or the refrigerant state at the outlet of the evaporator 14 taking into account the estimated enthalpy difference, and the opening of the expansion valve 13 may be controlled accordingly. Here, the heat exchange amount of the heat medium HM is estimated from, for example, the rotation speed of the pump 21 and the inlet / outlet temperatures (temperature of the heat medium HM) of the condenser 12 and / or the evaporator 14. The circulation amount of the refrigerant RF is estimated from, for example, the rotation speed and suction pressure of the compressor 11.

[0055] By making the refrigerant RF flowing out of the condenser 12 a two-phase gas-liquid refrigerant, the enthalpy difference (specific enthalpy difference) Δh in the evaporator 14 becomes smaller than when the expansion valve 13 is controlled so that the refrigerant RF is in a liquid phase (see <Flow of refrigerant and heat medium during steady-state operation in heater mode> above; shown by the dashed line in Figure 2), and the amount of heat exchange required for evaporation of the refrigerant RF can be reduced. As a result, even if the temperature difference between the refrigerant RF and the heat medium HM is small, the pressure and temperature in the evaporator 14 tend to increase, and the heater mode can be started up quickly.

[0056] Here, "when starting up the heater mode" refers to, for example, when the temperature of the heat medium HM is increased when the temperature of the heat medium HM is below a first predetermined temperature and / or when the pressure of the refrigerant RF is increased when the pressure of the refrigerant RF is below a first predetermined pressure, and typically this is after (immediately after) the control unit 40 issues a command to execute the heater mode.

[0057] The temperature of the heat medium HM means the temperature of the heat medium HM at the heat medium outlet of the evaporator 14. This temperature is measured, for example, by a temperature sensor (not shown) configured in the control unit 40 to be able to measure it. The pressure of the refrigerant RF means the pressure of the refrigerant RF in the evaporator 14. The pressure is measured by a pressure sensor (not shown) configured in the control unit 40 to be capable of measurement, for example. The temperature of the heat medium HM may be the temperature of the heat medium HM at the heat medium inlet of the indoor air conditioning unit 23.

[0058] For example, when the temperature of the heat medium HM reaches a second predetermined temperature that is higher than the first predetermined temperature and / or the pressure of the refrigerant RF reaches a second predetermined pressure that is higher than the first predetermined pressure, the control unit 40 terminates the control of the expansion valve 13 (control that keeps the refrigerant RF in a gas-liquid two-phase state) and transitions to normal control (control that keeps the refrigerant RF in a liquid phase).

[0059] To summarize the above, the control unit 40 determines whether the refrigerant RF flowing out of the condenser 12 will be in a gas-liquid two-phase state or a liquid phase state based on the temperature of the heat medium HM and / or the pressure of the refrigerant RF, and controls the expansion valve 13.

[0060] Since the refrigerant RF flowing out of the condenser 12 is in a gas-liquid two-phase state, the condenser refrigerant pipe L12 is not provided with a reserve tank (gas-liquid separator).

[0061] <Effects> By making the refrigerant RF flowing out from the condenser 12 into a two-phase gas-liquid state, the enthalpy difference Δh in the evaporator 14 becomes smaller than when the expansion valve 13 is controlled so that the refrigerant RF becomes liquid phase, and the amount of heat exchange required for evaporation of the refrigerant RF can be reduced. This reduces the temperature difference between the refrigerant RF and the heat medium HM in the evaporator 14, making it easier for the pressure and temperature in the evaporator 14 to increase, and enabling the heater mode to be started up early.

[0062] [Modification of the first embodiment] As shown in FIG. 3, the heat medium circuit 20 may include a junction valve 25 provided at the junction C instead of the branch valve 24 (see FIG. 1). In this case, the portion where the branch valve 24 was provided becomes a branch portion B where the temperature adjustment device outlet pipe L22 branches into the condenser inlet pipe L23 and the evaporator inlet pipe L24.

[0063] The junction valve 25 is a three-way valve, and has two inlets 25i1 and 25i2 and one outlet 25o. The junction valve 25 is a valve that causes the heat medium HM taken in at an arbitrary ratio from the inlets 25i1 and 25i2 to flow out from the outlet 25o. The confluence valve 25 is controlled by the control unit 40, and the ratio of the flow rates of the heat medium HM taken in from the inlets 25i1 and 25i2 is adjusted.

[0064] The other end of the condenser outlet pipe L25 is connected to the inlet 25i1. The other end of the evaporator outlet pipe L26 is connected to the inlet 25i2. One end of a pump inlet pipe L27 is connected to the outlet 25o. This makes it possible to adjust the ratio between the flow rate of the heat medium HM led to the condenser 12 and the flow rate of the heat medium HM led to the evaporator 14, similar to the action of the branch valve 24.

[0065] [Second embodiment] The temperature regulation system according to this embodiment differs from the first embodiment in the configuration of the heat medium circuit.

[0066] As shown in FIG. 4, the temperature adjustment system 2 includes a refrigerant circuit 10 configured to circulate a refrigerant RF, a heat medium circuit 30 configured to circulate a heat medium HM that exchanges heat with the refrigerant RF, and a control unit 40 that controls electric devices and electronic devices provided in each circuit.

[0067] <Configuration of refrigerant circuit and control unit> This is the same as in the first embodiment, so a detailed description thereof will be omitted here.

[0068] <Configuration of the heat medium circuit> The heat medium circuit 30 is configured so that the heat medium HM that exchanges heat with the refrigerant RF in the condenser 12 and the evaporator 14 of the refrigerant circuit 10 can circulate.

[0069] The heat medium circuit 30 includes a first pump 31 and a second pump 32 that pump the heat medium HM, an indoor air conditioning unit (temperature control device) 33, a branch valve 34 that branches one flow path into multiple flow paths, a merging valve 35 that merges the multiple flow paths into one flow path, and multiple pipes that connect the various devices. A heat medium HM is sealed in the heat medium circuit 20. The sealed heat medium HM circulates in the heat medium circuit 30 according to a cycle (heat medium loop) that corresponds to the operation mode.

[0070] The first pump 31 is a device that pumps the heat medium HM in a series of heat medium loops according to the operation mode. The rotation speed of the first pump 31 is controlled by the control unit 40.

[0071] A heat medium outlet (discharge port) of the first pump 31 is connected to one end of a first pump outlet pipe L31. The other end of the first pump outlet pipe L31 is connected to the heat medium inlet (inlet 35i1) of the junction valve 35. That is, the first pump outlet pipe L31 is a pipe that connects the discharge port of the first pump 31 and the inlet 35i1 of the junction valve 35.

[0072] The second pump 32 is a device that pumps the heat medium HM in a series of heat medium loops according to the operation mode. The rotation speed of the second pump 32 is controlled by the control unit 40.

[0073] A heat medium outlet (discharge port) of the second pump 32 is connected to one end of a second pump outlet pipe L32. The other end of the second pump outlet pipe L32 is connected to another heat medium inlet (inlet 35i2) of the junction valve 35. That is, the second pump outlet pipe L32 is a pipe that connects the discharge port of the second pump 32 and the inlet 35i2 of the junction valve 35.

[0074] The junction valve 35 is a three-way valve and has two inlets 35i1 and 35i2 and one outlet 35o. The junction valve 35 is a valve that causes the heat medium HM taken in at an arbitrary ratio from the inlets 35i1 and 35i2 to flow out from the outlet 35o. The confluence valve 35 is controlled by the control unit 40, and the ratio of the flow rates of the heat medium HM taken in from the inlets 35i1 and 35i2 is adjusted.

[0075] One end of the temperature adjusting device inlet pipe L33 is connected to the outlet 35o. The other end of the temperature adjustment equipment inlet pipe L33 is connected to the heat medium inlet of the indoor air conditioning unit 33. That is, the temperature adjustment equipment inlet pipe L33 is a pipe that connects the outlet 35o and the heat medium inlet of the indoor air conditioning unit 33.

[0076] The interior air conditioning unit 33 is a unit configured to supply conditioned air to the vehicle interior by exchanging heat between air sent by a fan (not shown) and the heat medium HM guided from the first pump 31 and / or the second pump 32 via the temperature control equipment inlet piping L33. The rotation speed of the fan (not shown) is controlled by the control unit 40.

[0077] A heat medium outlet of the indoor air conditioning unit 33 is connected to one end of a temperature adjustment device outlet pipe L34. The other end of the temperature adjustment device outlet pipe L34 is connected to the heat medium inlet (inlet 34i) of the branch valve 34. That is, the temperature adjustment equipment outlet pipe L34 is a pipe that connects the heat medium outlet of the indoor air conditioning unit 33 and the inlet 34i of the branch valve 34.

[0078] The branch valve 34 is a three-way valve, and has one inlet 34i and two outlets (heat medium outlets) 34o1 and 34o2. The branch valve 34 is a valve that distributes the heat medium HM, which is introduced from the indoor air conditioning unit 33 via the temperature adjustment equipment outlet pipe L34 and flows in from the inlet 34i, to the outlets 34o1, 34o2 in an arbitrary ratio. The branch valve 34 is controlled by the control unit 40, and the ratio of the flow rates of the heat medium HM guided to the outlets 34o1, 34o2 is adjusted.

[0079] An outlet 34o1 of the branch valve 34 is connected to one end of a condenser inlet pipe L35. The other end of the condenser inlet pipe L35 is connected to the heat medium inlet of the condenser 12. That is, the condenser inlet pipe L35 is a pipe that connects the outlet 34o1 of the branch valve 34 and the heat medium inlet of the condenser 12.

[0080] An outlet 34o2 of the branch valve 34 is connected to one end of an evaporator inlet pipe L36. The other end of the evaporator inlet pipe L36 is connected to the heat medium inlet of the evaporator 14. That is, the evaporator inlet pipe L36 is a pipe that connects the outlet 34o2 of the branch valve 34 and the heat medium inlet of the evaporator 14.

[0081] The condenser 12 is a heat exchanger that exchanges heat between the heat medium HM introduced from the branch valve via the condenser inlet pipe L35 and the refrigerant RF flowing through the refrigerant circuit .

[0082] The heat medium outlet of the condenser 12 is connected to one end of a condenser outlet pipe L37. The other end of the condenser outlet pipe L37 is connected to the heat medium inlet (suction port) of the first pump 31. That is, the condenser outlet pipe L37 is a pipe that connects the heat medium outlet of the condenser 12 and the suction port of the first pump 31.

[0083] The evaporator 14 is a heat exchanger that exchanges heat between the heat medium HM introduced from the branch valve 34 via the evaporator inlet pipe L36 and the refrigerant RF flowing through the refrigerant circuit 10.

[0084] The heat medium outlet of the evaporator 14 is connected to one end of an evaporator outlet pipe L38. The other end of the evaporator outlet pipe L38 is connected to the heat medium inlet (suction port) of the second pump 32. That is, the evaporator outlet pipe L38 is a pipe that connects the heat medium outlet of the evaporator 14 and the suction port of the second pump 32.

[0085] <Refrigerant and heat transfer medium flow during steady-state operation in heater mode> The heater mode is suitable for heating when the outside air temperature is low and heat cannot be absorbed from the outside air into the heat medium HM. In the heater mode, the heat medium HM is used to transfer an amount of heat corresponding to the power of the compressor 11 as a heat source to the vehicle compartment (interior air conditioning unit 33) while avoiding heat radiation from the heat medium HM to the outside air. That is, in the heater mode, the heat medium HM flowing out from the evaporator 14 circulates through the heat medium circuit 20 without being guided to an exterior heat exchanger (a heat exchanger that exchanges heat between the heat medium and the outside air), not shown. This ensures heating capacity even when the outside air temperature is significantly below 0°C.

[0086] The refrigerant RF is compressed by the compressor 11, and the high-temperature, high-pressure refrigerant RF is supplied to the condenser 12. In the condenser 12, the refrigerant RF exchanges heat with the heat medium HM to release heat, and the refrigerant RF is condensed and liquefied, and further subcooled. The liquefied high-pressure refrigerant RF is decompressed by an expansion valve 13 and then supplied to an evaporator 14. In the evaporator 14, the refrigerant RF exchanges heat with the heat medium HM to obtain latent heat of evaporation and evaporate, becoming a low-pressure gaseous refrigerant RF. The gasified refrigerant RF is sucked into the compressor 11. This cycle is then repeated.

[0087] The heat medium HM heated by the refrigerant RF in the condenser 12 is guided to the junction valve 35 via the condenser outlet pipe L37 (and the first pump 31) and the first pump outlet pipe L31. On the other hand, the heat medium HM cooled by the refrigerant RF in the evaporator 14 is guided to the junction valve 35 via the evaporator outlet pipe L38 (and the second pump 32) and the second pump outlet pipe L32. The heat medium HM guided to the junction valve 35 is guided to the indoor air conditioning unit 33 via the temperature adjustment equipment inlet pipe L33. The heat medium HM guided to the interior air conditioning unit 33 provides heat to the air in the vehicle interior, for example, to heat the vehicle interior. The heat medium HM cooled by providing heat is led to the branch valve 34 via the temperature adjustment device outlet pipe L34. The heat medium HM introduced to the branch valve 34 is distributed at an arbitrary ratio to the condenser inlet pipe L35 and the evaporator inlet pipe L36. The heat medium HM introduced to the condenser 12 absorbs heat from the refrigerant RF flowing through the condenser 12 to liquefy the refrigerant RF. On the other hand, the heat medium HM introduced to the evaporator 14 imparts latent heat of evaporation to the refrigerant RF flowing through the evaporator 14 to evaporate the refrigerant RF.

[0088] The flow of the heat medium HM described above is generated by the first pump 31, the second pump 32, the branch valve 34, and the merging valve 35. As long as the flow of the heat medium HM described above can be generated, the positions of the first pump 31, the second pump 32 and the various valves are not particularly limited.

[0089] <Flow of refrigerant and heat medium when starting up heater mode> This is the same as in the first embodiment, so a detailed description thereof will be omitted here.

[0090] [Modification 1 of the second embodiment]

[0091] As shown in FIG. 5, the condenser outlet pipe L37 and the evaporator outlet pipe L38 may be connected by a connecting pipe L39.

[0092] A reserve tank 36 is provided in the connecting pipe L39. The reserve tank 36 is a container that receives the heat medium HM when the volume of the heat medium HM expands with an increase in temperature and the volume exceeds the volume of the piping (limited to the portion where the heat medium HM loops) of the heat medium circuit 30. Conversely, when the volume of the heat medium HM decreases with a decrease in temperature, the heat medium HM is replenished from the reserve tank 36 to the piping of the heat medium circuit 30, so that the inside of the piping of the heat medium circuit 30 is maintained in a state filled with the heat medium HM.

[0093] When the pressure of the heat medium HM in the condenser outlet pipe L37 and the pressure of the heat medium HM in the evaporator outlet pipe L38 are balanced, no flow of the heat medium HM is formed in the connection pipe L39. On the other hand, if the pressure of the heat medium HM in the condenser outlet pipe L37 and the pressure of the heat medium HM in the evaporator outlet pipe L38 are not balanced, the pressure equalization effect provided by the connecting pipe L39 will result in the formation of a flow of the heat medium HM from one outlet pipe (for example, the evaporator outlet pipe L38) to the other outlet pipe (for example, the condenser outlet pipe L37).

[0094] [Modification 2 of the Second Embodiment] As shown in FIG. 6, for example, the second pump 32 may be stopped. In this case, the heat medium HM flowing out of the evaporator 14 does not pass through the second pump 32, but is guided to the condenser outlet pipe L37 (and thus the first pump 31) via the evaporator outlet pipe L38 and the connecting pipe L39. Therefore, the flow of the heat medium HM is generated only by the first pump 31.

[0095] The first pump 31 may be stopped and the second pump 32 may be operated.

[0096] [Note] The temperature regulation system and the control method for the temperature regulation system according to each embodiment described above can be understood, for example, as follows.

[0097] A temperature control system (1, 2) according to a first aspect of the present disclosure includes a refrigerant circuit (10) having a compressor (11), a high-pressure side heat exchanger (12), a pressure reducing section (13), and a low-pressure side heat exchanger (14), through which a refrigerant (RF) circulates, a heat medium circuit (20) through which a heat medium (HM) that exchanges heat with the refrigerant in the high-pressure side heat exchanger and the low-pressure side heat exchanger circulates, and a control section (40). The heat medium circuit includes a temperature control device (23) that heats a temperature control target using the heat medium. , 33), and the control unit controls the pressure reducing unit by determining whether the refrigerant flowing out from the high-pressure side heat exchanger is in a gas-liquid two-phase state or a liquid phase state in a heater mode in which the heat medium flowing out from the high-pressure side heat exchanger is mixed with the heat medium flowing out from the low-pressure side heat exchanger, the mixed heat medium is allowed to flow into the high-pressure side heat exchanger and the low-pressure side heat exchanger, and the heat medium flowing out from the high-pressure side heat exchanger is allowed to flow into the temperature adjustment device.

[0098] In the temperature control system according to this aspect, the control unit controls the pressure reducing unit by determining whether the refrigerant flowing out of the high-pressure heat exchanger is in a gas-liquid two-phase state or a liquid state based on the temperature of the heat medium and / or the pressure of the refrigerant. For example, if the refrigerant is in a gas-liquid two-phase state when starting up the heater mode, the enthalpy difference in the low-pressure heat exchanger is smaller than when the pressure reducing unit is controlled to keep the refrigerant in a liquid state (for example, when the refrigerant flowing out of the high-pressure heat exchanger is subcooled), and the amount of heat exchange required for evaporating the refrigerant can be reduced. This reduces the temperature difference between the refrigerant and the heat medium, making it easier for the pressure and temperature in the evaporator to increase, and allowing the heater mode to be started up more quickly.

[0099] In the temperature control system according to the second aspect of the present disclosure, in the first aspect, the control unit controls the pressure reducing unit so that the refrigerant flowing out of the high-pressure side heat exchanger is in a gas-liquid two-phase state when the temperature of the heat medium is below a first predetermined temperature.

[0100] In the temperature control system according to the third aspect of the present disclosure, in the second aspect, the control unit controls the pressure reducing unit so that the refrigerant flowing out of the high-pressure side heat exchanger is in a gas-liquid two-phase state when the temperature of the heat medium is equal to or higher than a second predetermined temperature that is higher than the first predetermined temperature.

[0101] In the temperature control system according to the fourth aspect of the present disclosure, in the first or second aspect, the control unit controls the pressure reducing unit so that the refrigerant flowing out from the high-pressure side heat exchanger is in a liquid phase when the pressure of the refrigerant in the low-pressure side heat exchanger is equal to or lower than a first predetermined pressure.

[0102] In a temperature control system according to a fifth aspect of the present disclosure, in the fourth aspect, the control unit controls the pressure reducing unit so that the refrigerant flowing out of the high-pressure side heat exchanger is in a liquid phase when the pressure of the refrigerant in the low-pressure side heat exchanger is equal to or higher than a second predetermined pressure that is higher than the first predetermined pressure.

[0103] In a temperature control system according to a sixth aspect of the present disclosure, in any of the first, second and fourth aspects, the control unit estimates the state of the refrigerant flowing out from the high-pressure side heat exchanger based on the temperature of the heat medium at the inlet / outlet of the high-pressure side heat exchanger and / or the temperature of the heat medium at the inlet / outlet of the low-pressure side heat exchanger, the rotation speed and suction pressure of the compressor, and controls the pressure reduction unit so that the refrigerant becomes in a two-phase gas-liquid state.

[0104] A temperature control system according to a seventh aspect of the present disclosure is provided with a refrigerant circuit having a compressor, a high-pressure side heat exchanger, a pressure reduction unit, and a low-pressure side heat exchanger, and comprising: a refrigerant circuit through which a refrigerant circulates; and a heat medium circuit through which a heat medium that exchanges heat with the refrigerant in the high-pressure side heat exchanger and the low-pressure side heat exchanger circulates, wherein the heat medium circuit has a temperature control device that heats a temperature control target using the heat medium. A control method for a temperature control system is provided, wherein the heat medium flowing out of the high-pressure side heat exchanger is mixed with the heat medium flowing out of the low-pressure side heat exchanger, the mixed heat medium is caused to flow into the high-pressure side heat exchanger and the low-pressure side heat exchanger, and the heat medium flowing out of the high-pressure side heat exchanger is caused to flow into the temperature control device, and the pressure reduction unit is adjusted by determining whether the refrigerant flowing out of the high-pressure side heat exchanger is in a gas-liquid two-phase state or a liquid state. [Explanation of symbols]

[0105] 1,2 Temperature control system 10 Refrigerant circuit 11 Compressor 12 Condenser (high pressure side heat exchanger) 13 Expansion valve (pressure reducing section) 14 Evaporator (low-pressure side heat exchanger) L11 Compressor refrigerant piping L12 Condenser refrigerant piping L13 Expansion valve refrigerant piping L14 Evaporator refrigerant piping 20 Heat carrier circuit 21 Pump 23 Indoor air conditioning unit (temperature control equipment) 24 Branch valve 24i inlet 24o1 Outlet 24o2 Outlet 25 Confluence valve 25i1 Inlet 25i2 Inlet 25o outlet L21 Pump outlet piping L22 Temperature controller outlet piping L23 Condenser inlet piping L24 Evaporator inlet piping L25 Condenser outlet piping L26 Evaporator outlet piping L27 Pump inlet piping 30 Heat carrier circuit 31 First Pump 32 Second Pump 33 Indoor air conditioning unit (temperature control equipment) 34 Branch valve 34i inlet 34o1 Outlet 34o2 Outlet 35 Confluence valve 35i1 Inlet 35i2 Inlet 35o outlet 36 Reserve tank L31 First pump outlet piping L32 Second pump outlet piping L33 Temperature control equipment inlet piping L34 Temperature controller outlet piping L35 Condenser inlet piping L36 Evaporator inlet piping L37 Condenser outlet piping L38 Evaporator outlet piping L39 Connection piping 40 Control Unit B Branch C Confluence

Claims

1. a refrigerant circuit including a compressor, a high-pressure side heat exchanger, a pressure reducing section, and a low-pressure side heat exchanger, in which a refrigerant circulates; a heat medium circuit through which a heat medium circulates that exchanges heat with the refrigerant in the high-pressure side heat exchanger and the low-pressure side heat exchanger; A control unit; Equipped with the heat medium circuit has a temperature control device that heats a temperature control target using the heat medium, The control unit In a heater mode, the heat medium flowing out of the high-pressure side heat exchanger is mixed with the heat medium flowing out of the low-pressure side heat exchanger, the mixed heat medium is caused to flow into the high-pressure side heat exchanger and the low-pressure side heat exchanger, and the heat medium flowing out of the high-pressure side heat exchanger is caused to flow into the temperature adjustment device, The pressure reducing unit is controlled by determining whether the refrigerant flowing out from the high-pressure side heat exchanger is in a gas-liquid two-phase state or a liquid phase state. Temperature control system.

2. The control unit controls the pressure reducing unit so that the refrigerant flowing out from the high-pressure side heat exchanger is in a gas-liquid two-phase state when the temperature of the heat medium at the heat medium outlet of the low-pressure side heat exchanger or the heat medium inlet of the temperature adjustment device is equal to or lower than a first predetermined temperature. The temperature control system according to claim 1 .

3. The control unit controls the pressure reducing unit so that the refrigerant flowing out of the high-pressure side heat exchanger is in a gas-liquid two-phase state when the temperature of the heat medium is equal to or higher than a second predetermined temperature that is higher than the first predetermined temperature. The temperature control system according to claim 2 .

4. The control unit controls the pressure reducing unit so that the refrigerant flowing out of the high-pressure side heat exchanger is in a liquid phase when the pressure of the refrigerant in the low-pressure side heat exchanger is equal to or lower than a first predetermined pressure. The temperature control system according to claim 1 .

5. The control unit controls the pressure reducing unit so that the refrigerant flowing out of the high-pressure side heat exchanger is in a liquid phase when the pressure of the refrigerant in the low-pressure side heat exchanger is equal to or higher than a second predetermined pressure that is higher than the first predetermined pressure. The temperature control system according to claim 4 .

6. The control unit estimates a state of the refrigerant flowing out from the high-pressure side heat exchanger based on a temperature of the heat medium at an inlet / outlet of the high-pressure side heat exchanger and / or a temperature of the heat medium at an inlet / outlet of the low-pressure side heat exchanger, a rotation speed and a suction pressure of the compressor, and controls the decompression unit so that the refrigerant is in a gas-liquid two-phase state. The temperature control system according to any one of claims 1, 2 and 4.

7. a refrigerant circuit including a compressor, a high-pressure side heat exchanger, a pressure reducing section, and a low-pressure side heat exchanger, in which a refrigerant circulates; a heat medium circuit through which a heat medium circulates that exchanges heat with the refrigerant in the high-pressure side heat exchanger and the low-pressure side heat exchanger; Equipped with The heat medium circuit has a temperature control device that heats a temperature control target using the heat medium. A method for controlling a temperature adjustment system, comprising: In a heat medium loop in a heater mode in which the heat medium flowing out of the high-pressure side heat exchanger is mixed with the heat medium flowing out of the low-pressure side heat exchanger, the mixed heat medium is flowed into the high-pressure side heat exchanger and the low-pressure side heat exchanger, and the heat medium flowing out of the high-pressure side heat exchanger is flowed into the temperature control device, the pressure reducing section is adjusted by determining whether the refrigerant flowing out of the high-pressure side heat exchanger is in a gas-liquid two-phase state or a liquid phase state. A method for controlling a temperature control system.

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