Temperature adjustment system and method for controlling temperature adjustment system

Abstract

Provided is a temperature adjustment system (100) wherein: a heat medium circuit (20) has an indoor air-conditioning unit (25) that heats or cools a temperature-control target by means of a heat medium (HM), a three-way valve (26) that causes the heat medium (HM) to branch into at least one of condenser piping (L1) and evaporator piping (L5), a flow path merging part (C) that merges the heat medium (HM) flowing through the condenser piping (L1) and the heat medium (HM) flowing through the evaporator piping (L5), and a first pump (21) that is disposed upstream of the three-way valve (26) in a circulation direction and downstream of the flow path merging part (C) in the circulation direction, and pumps the heat medium (HM) along the circulation direction; and a control unit (30) controls the three-way valve (26) and the first pump (21) so as to execute a first heater mode in which the heat medium (HM) is branched into the condenser piping (L1) and the evaporator piping (L5) by the three-way valve (26), and the heat medium (HM) is merged in the flow path merging part (C) and guided to the indoor air conditioning unit (25).

Description

Temperature control system and method for controlling the temperature control system

[0001] The present disclosure relates to a temperature control system suitable for use in a vehicle and a method for controlling a temperature control system.

[0002] A vehicle thermal management system has been known that has an operating mode for quickly heating a target device when the outside air temperature is low (see, for example, Patent Document 1). The vehicle thermal management system disclosed in Patent Document 1 has a low-pressure side heat exchanger included in a refrigeration cycle arranged in a first heat medium circuit, a high-pressure side heat exchanger included in the refrigeration cycle arranged in a second heat medium circuit, and is capable of switching between a non-connected mode in which the first heat medium circuit and the second heat medium circuit are not connected, and a connected mode in which the first heat medium circuit and the second heat medium circuit are connected.

[0003] In Patent Document 1, when supplying heat medium to the equipment to be heated, the heat medium discharged from the pump is branched by a first switching valve into three systems: a low-pressure side heat exchanger, a 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 a second switching valve, and then directed back to the pump.

[0004] JP 2014-201148 A

[0005] However, in Patent Document 1, because a portion of the flow rate of the heat medium discharged from the pump is guided to the low-pressure side heat exchanger and the high-pressure side heat exchanger by the first switching valve, the flow rate of the heat medium passing through the equipment to be heated becomes less than the flow rate of the heat medium discharged from the pump. In order to heat the equipment to a desired temperature, it is necessary to increase the temperature of the heat medium by the amount that the flow rate of the heat medium passing through the equipment to be heated decreases, resulting in a decrease in thermal efficiency.

[0006] The present disclosure has been made in consideration of these circumstances, and aims to provide a temperature control system and a control method for a temperature control system that can improve thermal efficiency when executing a temperature control mode that uses the power of a compressor to heat the temperature control target.

[0007] A temperature control system according to one aspect of the present disclosure includes a refrigerant circuit in which a refrigerant circulates through a compressor, a high-pressure side heat exchanger, a pressure reducing unit, and a low-pressure side heat exchanger; a heat medium circuit in 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; and a control unit that controls the refrigerant circuit and the heat medium circuit. The heat medium circuit includes a temperature control device that heats a temperature control target using the heat medium, a flow path branching unit that is arranged downstream of the temperature control device in the flow direction and that branches the heat medium into at least one of a first heat medium flow path that leads to the high-pressure side heat exchanger and a second heat medium flow path that leads to the low-pressure side heat exchanger, and a flow path branching unit that is arranged downstream of the temperature control device in the flow direction. a flow path junction arranged on the downstream side of the flow path and merging the heat medium flowing through the first heat medium flow path and the heat medium flowing through the second heat medium flow path; and a first pump arranged upstream of the flow path branching section in the flow direction and downstream of the flow path junction in the flow direction and pressurizing the heat medium along the flow direction, wherein the control unit controls the flow path branching section, the flow path junction, and the first pump to execute a heater mode in which the heat medium is branched into the first heat medium flow path and the second heat medium flow path at the flow path branching section, and the heat medium that has passed through the first heat medium flow path and the second heat medium flow path is merged at the flow path junction and led to the temperature adjustment device.

[0008] In a control method for a temperature adjustment system according to one aspect of the present disclosure, the temperature adjustment system includes a refrigerant circuit in which a refrigerant circulates through a compressor, a high-pressure side heat exchanger, a pressure reducing unit, and a low-pressure side heat exchanger, and a heat medium circuit in which a heat medium circulates to exchange heat with the refrigerant in the high-pressure side heat exchanger and the low-pressure side heat exchanger, the heat medium circuit including a temperature adjustment device that heats an object to be temperature adjusted using the heat medium, a flow path branching unit that is arranged downstream of the temperature adjustment device in the flow direction and that branches the heat medium into at least one of a first heat medium flow path that leads the heat medium to the high-pressure side heat exchanger and a second heat medium flow path that leads the heat medium to the low-pressure side heat exchanger, and a flow path branching unit that is arranged upstream of the temperature adjustment device in the flow direction. the heat medium flowing through the first heat medium flow path and the heat medium flowing through the second heat medium flow path; and a first pump that is arranged upstream of the flow path branching section in the flow direction and downstream of the flow path junction in the flow direction and that pressurizes the heat medium along the flow direction, and the heat medium flowing through the first heat medium flow path and the second heat medium flow path is branched at the flow path branching section into the first heat medium flow path and the second heat medium flow path, and the heat medium that has passed through the first heat medium flow path and the second heat medium flow path is joined at the flow path junction and introduced to the temperature adjustment device.

[0009] According to the present disclosure, it is possible to provide a temperature adjustment system and a control method for a temperature adjustment system that can improve thermal efficiency when executing a temperature adjustment mode in which the power of a compressor is used to heat an object to be temperature-adjusted.

[0010] 1 is a schematic configuration diagram showing a temperature control system according to an embodiment of the present disclosure, showing a state in which a first heater mode is being executed; FIG. 2 is a schematic configuration diagram showing a temperature control system according to an embodiment of the present disclosure, showing a state in which a heat pump mode is being executed; FIG. 3 is a schematic configuration diagram showing a temperature control system according to an embodiment of the present disclosure, showing a state in which a second heater mode is being executed; and FIG. 4 is a schematic configuration diagram showing a temperature control system according to an embodiment of the present disclosure, showing a state in which a cooling mode is being executed.

[0011] A temperature control system 100 according to an embodiment of the present disclosure will be described below with reference to the drawings. The vehicle temperature control system 100 shown in Fig. 1 is installed in a vehicle (not shown), such as an electric vehicle that does not have an engine and obtains driving force for running the vehicle from an electric motor, or a so-called hybrid vehicle that obtains driving force for running the vehicle from an engine and an electric motor.

[0012] The temperature adjustment system 100 is responsible for air conditioning such as heating and cooling, dehumidification, and ventilation of the passenger compartment, as well as heat management and exhaust heat recovery for on-board devices such as the battery device (power supply device) mounted on the vehicle, the traction motor, and heat-generating electronic devices. 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."

[0013] The temperature adjustment system 100 and the electrically powered devices and electronic devices provided in the on-board devices are supplied with power stored in an on-board battery device. The on-board battery device is charged from an external power source when the vehicle is stopped.

[0014] The temperature adjustment system 100 includes a refrigerant circuit 10 configured to allow refrigerant to circulate, a heat medium circuit 20 configured to allow a heat medium that transfers heat to and from the refrigerant to circulate, and a control unit 30 that sets the temperature adjustment system 100 to a predetermined operating mode and controls the operating state of the temperature adjustment system 100 in accordance with the operating mode. The temperature adjustment system 100 includes sensors (not shown), such as a sensor that detects the outside air temperature and a sensor that detects the temperature of conditioned air blown into the vehicle cabin.

[0015] The temperature adjustment system 100 can execute one of a plurality of operating modes selected by the occupant or the control unit 30. In this embodiment, the operating modes of the temperature adjustment system 100 are exemplified by a first heater mode (FIG. 1), a heat pump mode (FIG. 2), a second heater mode (FIG. 3), and a cooling mode (FIG. 4).

[0016] <Configuration of Refrigerant Circuit 10> The refrigerant circuit 10 includes a compressor 11 that compresses the refrigerant RF, a condenser (high-pressure side heat exchanger) 12, an expansion valve (pressure reducing section) 13, and an evaporator (low-pressure side heat exchanger) 14. The refrigerant RF circulates through the refrigerant circuit 10 according to a refrigeration cycle. The refrigerant RF charged into the refrigerant circuit 10 can be a single refrigerant or a mixed refrigerant. For example, HFC (hydrofluorocarbon) refrigerants such as R410A and R32, HFO (hydrofluoroolefin) refrigerants such as R1234ze and R1234yf, or hydrocarbon (HC) refrigerants such as propane and isobutane can be used. In particular, R1234yf is preferably used as the refrigerant in this embodiment.

[0017] When the above-listed fluorocarbon or hydrocarbon refrigerants are used, a subcritical refrigeration cycle is configured in which the refrigerant pressure on the high-pressure side does not exceed the critical pressure of the refrigerant. When carbon dioxide (CO2) is used as the refrigerant, a transcritical refrigeration cycle is configured in which the refrigerant pressure on the high-pressure side exceeds the critical pressure of the refrigerant. Even in this case, the refrigerant dissipates heat through the high-pressure side heat exchanger, as in the condenser 12 of this embodiment, and absorbs heat through the low-pressure side heat exchanger, as in the evaporator 14 of this embodiment. Therefore, refrigerants that configure a transcritical refrigeration cycle, such as carbon dioxide refrigerants, can also be used in the refrigerant circuit 10.

[0018] 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 30. The compressor 11 may be, for example, a scroll compressor or a rotary compressor.

[0019] The condenser 12 is a device that exchanges heat between the refrigerant RF discharged from the compressor 11 and the heat medium HM flowing through the heat medium circuit 20 .

[0020] The expansion valve 13 reduces the pressure of the refrigerant RF flowing out from the condenser 12. As the expansion valve 13, a thermostatic expansion valve or an electronic expansion valve whose opening can be controlled based on a command from the control unit 30 can be used. Note that a capillary tube may be used instead of the expansion valve 13. Furthermore, a receiver (gas-liquid separator) (not shown) may be provided between the condenser 12 and the expansion valve 13.

[0021] The evaporator 14 is a device that exchanges heat between the refrigerant RF flowing out of the expansion valve 13 and the heat medium HM flowing through the heat medium circuit 20. The refrigerant RF evaporated by the evaporator 14 is guided to the suction side of the compressor 11. An accumulator (gas-liquid separator) (not shown) may be provided between the evaporator 14 and the compressor 11.

[0022] The expansion valve 15 reduces the pressure of the refrigerant RF flowing out from the condenser 12. As the expansion valve 15, a thermostatic expansion valve or an electronic expansion valve whose opening can be controlled based on commands from the control unit 30 can be used. Note that a capillary tube may be used instead of the expansion valve 15. Furthermore, a receiver (gas-liquid separator) (not shown) may be provided between the condenser 12 and the expansion valve 15.

[0023] The compressor 11, the condenser 12, the expansion valve 13, the evaporator 14, the expansion valve 15, and the refrigerant piping connecting these elements are installed, for example, outside the passenger compartment.

[0024] <Configuration of Heat Medium Circuit 20> The heat medium circuit 20 is configured to circulate a heat medium HM capable of transferring heat to and from the refrigerant RF via the condenser 12 and the evaporator 14. The heat medium HM is used to cool or heat at least one temperature control target. In this embodiment, the temperature control target is air that is supplied to the vehicle interior for air conditioning. The temperature control target may also be an on-board battery device.

[0025] 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 the brine include a mixture of water and propylene glycol, or a mixture of water and ethylene glycol.

[0026] The heat medium circuit 20 includes a first pump 21, a second pump 22, an outdoor heat exchanger 23, a circulation flow path 24, an indoor air conditioning unit (temperature control device) 25, a three-way valve (flow path branching section) 26, a three-way valve (flow path switching section) 27, a three-way valve (flow path switching section) 28, and a reserve tank 29.

[0027] The control unit 30 controls the start and stop and rotation speed of the first pump 21 and the second pump 22 .

[0028] The first pump 21 is disposed upstream of the three-way valve 26 in the flow direction of the heat medium HM and downstream of the flow path junction C in the flow direction, and is a device for pumping the heat medium HM along the flow direction. The first pump 21 is disposed between a first pump inlet pipe L2 connected to a condenser pipe (first heat medium flow path) L1 in which the condenser 12 is disposed, and a second indoor air-conditioning heat exchanger inlet pipe L3. The flow path junction C is provided between the condenser pipe L1 and the first pump inlet pipe L2.

[0029] The second pump 22 is connected to a circulation flow path 24 that branches off from an evaporator pipe (second heat medium flow path) L5 in which the evaporator 14 is disposed at a branch position B. The second pump 22 is a device that is disposed in the circulation flow path 24 and pressure-feeds the heat medium HM from the evaporator pipe L5 to the outdoor heat exchanger 23.

[0030] The exterior heat exchanger 23 is a device that exchanges heat between the heat medium and the outside air outside the vehicle cabin. The exterior heat exchanger 23 is disposed, for example, near an air inlet of the vehicle. The outside air supplied to the exterior heat exchanger 23 by the vehicle running and the operation of the exterior heat exchanger fan 23 a radiates or absorbs heat based on the temperature difference between the outside air and the heat medium.

[0031] The circulation flow path 24 is a flow path that branches the heat medium HM from the evaporator pipe L5 downstream of the evaporator 14 in the flow direction of the heat medium HM and causes the heat medium HM to flow into the evaporator pipe L5 at a three-way valve 27 upstream of the evaporator 14 in the flow direction.

[0032] The interior air-conditioning unit 25 includes an interior air-conditioning fan 25a, a first interior air-conditioning heat exchanger 25b, a second interior air-conditioning heat exchanger 25c, and a damper 25d. The interior air-conditioning unit 25 provides conditioned air to the vehicle cabin by exchanging heat between the air sent by the interior air-conditioning fan 25a and a heat medium. The interior air-conditioning fan 25a is driven by an electric motor based on commands from the control unit 30, and blows air from the vehicle cabin (interior air), outside air, or a mixture of the interior air and outside air toward the first interior air-conditioning heat exchanger 25b and the second interior air-conditioning heat exchanger 25c. When the temperature control system 100 executes the first heater mode, second heater mode, and heat pump mode described below, the damper 25d is positioned away from the second indoor air conditioning heat exchanger 25c so that air blown from the indoor air conditioning fan 25a can circulate through the second indoor air conditioning heat exchanger 25c.

[0033] A second indoor air-conditioning heat exchanger outlet pipe L6 is provided on the heat medium outlet side of the second indoor air-conditioning heat exchanger 25c. The second indoor air-conditioning heat exchanger outlet pipe L6 is connected to the three-way valve 26.

[0034] The three-way valve 26 is disposed downstream of the indoor air-conditioning unit 25 in the flow direction of the heat medium HM, and is a device that branches the heat medium HM into at least one of a condenser pipe L1 that leads to the condenser 12 and an evaporator pipe L5 that leads to the evaporator 14. The three-way valve 26 is controlled by a control unit 30, and the connection direction is switched depending on the operation mode.

[0035] The three-way valve 27 is a device that switches between a circulation state in which the heat medium HM flows through the circulation flow path 24 and a non-circulation state in which the heat medium HM does not flow through the circulation flow path 24. The three-way valve 27 is disposed in the circulation flow path 24 downstream of the outdoor heat exchanger 23 in the circulation direction and upstream of the evaporator 14 in the circulation direction. The three-way valve 27 is controlled by the control unit 30, and can switch the connection direction or prevent the heat medium from flowing depending on the operation mode.

[0036] The three-way valve 28 is a device that switches between a circulation state in which the heat medium HM flows through the circulation flow path 24 and a non-circulation state in which the heat medium HM does not flow through the circulation flow path 24. The three-way valve 28 is disposed in the circulation flow path 24 downstream of the second pump 22 in the circulation direction and upstream of the outdoor heat exchanger 23 in the circulation direction. The three-way valve 28 is controlled by the control unit 30, and can switch the connection direction or prevent the heat medium from flowing depending on the operation mode.

[0037] The reserve tank 29 is a device that is arranged downstream in the flow direction of the heat medium HM from the branch position B where the evaporator pipe L5 branches off to the circulation flow path 24, and that stores the heat medium HM. When the heat medium HM sealed in the heat medium circuit 20 expands with an increase in temperature, the reserve tank 29 receives the heat medium HM in an amount that exceeds the capacity of the pipes of the heat medium circuit 20.

[0038] Furthermore, when the volume of the heat medium HM decreases with a drop in temperature, the heat medium HM is replenished from the reserve tank 29 to the evaporator pipe L5, so that the evaporator pipe L5 is kept filled with the heat medium HM. In other words, the reserve tank 29 can prevent the internal pressure of the evaporator pipe L5 from becoming excessively high or the pressure inside the evaporator pipe L5 from becoming negative. The interior of the reserve tank 29 is open to the atmosphere. The reserve tank 29 may be sealed and adjusted to a desired constant pressure.

[0039] The reserve tank 29 is preferably arranged in a portion of the evaporator pipe L5 extending from the branch position B to the confluence C, closer to the confluence C than the branch position B. This arrangement prevents the suction pressure of the first pump 21 from becoming negative, thereby preventing a negative pressure region from being formed in the heat medium circuit 20. The three-way valves 27 and 28 may be integrated valves using the same actuator. A flow path switching valve may be provided at the confluence C. The target to be temperature-controlled may be cooled by guiding the heat medium cooled in the evaporator 14 to a temperature control device using a flow path switching valve (not shown).

[0040] <Configuration of the control unit 30> The control unit 30 is a device that controls the refrigerant circuit 10 and the heat medium circuit 20. The control unit 30 is configured, for example, with a central processing unit (CPU), random access memory (RAM), read-only memory (ROM), and a computer-readable storage medium. A series of processes for realizing various functions is stored in a storage medium or the like in the form of a program, for example. The CPU reads this program into the RAM or the like 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.

[0041] Next, the control of the temperature adjustment system 100 configured as described above will be described. <First heater mode: FIG. 1> The first heater mode (temperature adjustment mode) is suitable for heating when the heat medium HM cannot absorb heat from the outside air due to low outside air temperature. In the first heater mode, the heat medium HM transports an amount of heat corresponding to the power of the compressor 11 as a heat source to the vehicle cabin while avoiding heat radiation from the heat medium HM to the outside air. This ensures heating capacity even when the outside air temperature is significantly below 0°C. In the heat medium circuit 20 shown in FIG. 1, the areas where the heat medium HM flows are indicated by thick dashed lines, and the areas where the heat medium HM does not flow are indicated by thin dotted lines.

[0042] The refrigerant circuit 10 is started in response to a command from the control unit 30. As a result, 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, thereby releasing heat and condensing the refrigerant RF into a liquid. The liquefied high-pressure refrigerant RF is decompressed by the expansion valve 13 and then supplied to the evaporator 14.

[0043] In the evaporator 14, the refrigerant RF exchanges heat with the heat medium HM to obtain latent heat of evaporation and evaporate, becoming low-pressure gaseous refrigerant RF. The refrigerant RF that leaves the evaporator 14 is guided to the compressor 11 and repeats the above-mentioned refrigeration cycle. In the refrigerant circuit 10 shown in Figure 1, the areas where the refrigerant RF flows are indicated by thick solid lines, and the areas where the refrigerant RF does not flow are indicated by thin dotted lines.

[0044] The heat medium HM heated by the refrigerant RF in the condenser 12 is guided to the second interior air-conditioning heat exchanger inlet pipe L3 through the condenser pipe L1 and the flow path junction C by the action of the first pump 21. The heat medium HM then provides heat to the air in the vehicle cabin (or outside air) guided from the interior air-conditioning fan 25a in the second interior air-conditioning heat exchanger 25c, thereby heating the vehicle. The heat medium HM cooled by providing heat is guided to the three-way valve 26 through the second interior air-conditioning heat exchanger outlet pipe L6.

[0045] The control unit 30 controls the three-way valve 26, the three-way valve 27, the three-way valve 28, and the first pump 21 to execute a first heater mode in which the three-way valve 26 branches the heat medium HM into the condenser pipe L1 and the evaporator pipe L5, the three-way valves 27 and 28 guide the heat medium HM branched into the evaporator pipe L5 from the evaporator pipe L5 to the flow path junction C, and the heat medium HM that has passed through the condenser pipe L1 and the evaporator pipe L5 is joined at the flow path junction C and guided to the indoor air conditioning unit 25.

[0046] The heat medium HM flowing to the condenser 12 absorbs heat from the refrigerant RF flowing through the condenser 12 and liquefies the refrigerant RF. The heat medium HM flowing to the evaporator 14 imparts latent heat of evaporation to the refrigerant RF flowing through the evaporator 14, causing the refrigerant RF to evaporate.

[0047] The three-way valve 26 is configured to adjust a first flow rate of the heat medium HM introduced to the condenser pipe L1 and a second flow rate of the heat medium HM introduced to the evaporator pipe L5. The control unit 30 controls the three-way valve 26 to adjust the first flow rate and the second flow rate, for example, based on the pressure and / or temperature of the refrigerant RF flowing into the evaporator 14. The control unit 30 controls the three-way valve 26 to reduce the second flow rate when reducing the pressure of the refrigerant RF flowing into the evaporator 14. The control unit 30 may reduce the flow rate of the heat medium HM flowing into the evaporator 14 by, for example, reducing the rotation speed of the first pump 21.

[0048] Furthermore, the control unit 30 controls the three-way valve 26 to adjust the first flow rate and the second flow rate, for example, based on the pressure and / or temperature of the refrigerant RF flowing into the condenser 12. When the pressure of the refrigerant RF flowing into the condenser 12 is to be reduced, the control unit 30 controls the three-way valve 26 to increase the first flow rate. The control unit 30 may increase the flow rate of the heat medium HM flowing into the condenser 12, for example, by increasing the rotation speed of the first pump 21. Furthermore, the control unit 30 may control the rotation speed of the compressor 11 based on the temperature of the heat medium HM flowing into the second indoor air-conditioning heat exchanger 25c.

[0049] In the heat pump mode, heat is pumped from the outside air as a heat source to heat the vehicle interior. The operation of the refrigerant circuit 10 is the same as in the first heater mode, and therefore a description thereof will be omitted.

[0050] The heat medium HM heated by the refrigerant RF in the condenser 12 is guided to the second interior air-conditioning heat exchanger inlet pipe L3 through the condenser pipe L1 by the action of the first pump 21. The heat medium HM then provides heat to the air in the vehicle cabin (or outside air) guided from the interior air-conditioning fan 25a in the second interior air-conditioning heat exchanger 25c, thereby heating the vehicle. The heat medium HM cooled by providing heat is guided to the three-way valve 26 through the second interior air-conditioning heat exchanger outlet pipe L6.

[0051] The control unit 30 executes a heat pump mode in which the three-way valve 26 guides the heat medium HM from the second indoor air-conditioning heat exchanger outlet pipe L6 only to the condenser pipe L1, and the three-way valve 28 guides the heat medium HM that has passed through the condenser pipe L1 to the indoor air-conditioning unit 25, thereby forming a first circulation system, and the three-way valves 27 and 28 guide the heat medium HM from the evaporator pipe L5 to the circulation flow path 24, thereby forming a second circulation system. The control unit 30 controls the three-way valves 26, 27, 28, the first pump 21, and the second pump 22 to execute the heat pump mode.

[0052] <Second heater mode: FIG. 3> The second heater mode (temperature control mode) is suitable for heating when removing frost that has adhered to the exterior heat exchanger 23. In the second heater mode, the heat medium HM transfers an amount of heat corresponding to the power of the compressor 11 as a heat source to the exterior heat exchanger 23 and the vehicle compartment. This ensures both the defrosting and heating capabilities of the exterior heat exchanger 23. In the heat medium circuit 20 shown in FIG. 3, the portions through which the heat medium HM flows are indicated by thick dashed lines, and the portions through which the heat medium HM does not flow are indicated by thin dotted lines.

[0053] In the first heater mode, the heat medium HM is branched from the three-way valve 26 to the condenser pipe L1 and the evaporator pipe L5, while the heat medium HM is not supplied from the evaporator pipe L5 to the circulation flow path 24. Therefore, in the first heater mode, the heat medium HM does not flow to the outdoor heat exchanger 23.

[0054] On the other hand, in the second heater mode, the heat medium HM is branched from the three-way valve 26 to the condenser pipe L1 and the evaporator pipe L5, and the heat medium HM is supplied from the evaporator pipe L5 to the circulation flow path 24. Therefore, in the second heater mode, the heat medium HM flows through the outdoor heat exchanger 23. According to the second heater mode, in a situation where the outdoor air temperature is significantly below 0°C, it is possible to defrost the outdoor heat exchanger 23 while ensuring heating capacity.

[0055] In the second heater mode, the operation of the refrigerant circuit 10 is the same as in the first heater mode, and therefore a description thereof will be omitted.

[0056] The control unit 30 controls the three-way valve 26, the three-way valve 27, the three-way valve 28, and the first pump 21 to execute a second heater mode in which the three-way valve 26 branches the heat medium HM into the condenser pipe L1 and the evaporator pipe L5, the heat medium HM that has passed through the condenser pipe L1 and the evaporator pipe L5 is joined at the flow path junction C, and the three-way valves 27 and 28 guide the heat medium HM to the indoor air-conditioning unit 25 and the outdoor heat exchanger 23. The heat medium HM branched from the second indoor air-conditioning heat exchanger inlet pipe L3 to the three-way valve 28 is guided to the circulation flow path 24, passes through the outdoor heat exchanger 23, and is supplied to the three-way valve 27.

[0057] <Cooling Mode: FIG. 4> In the cooling mode, the interior air conditioning unit 25 supplies cool air to the vehicle interior.

[0058] The refrigerant circuit 10 is started in response to a command from the control unit 30. As a result, the refrigerant 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 is condensed and liquefied by heat exchange with the heat medium HM. The liquefied high-pressure refrigerant RF is decompressed by the expansion valve 15 and then supplied to the first interior air-conditioning heat exchanger 25b. In the first interior air-conditioning heat exchanger 25b, the refrigerant RF provides cold energy to the air in the vehicle cabin (or outside air) guided by the interior air-conditioning fan 25a, thereby cooling the vehicle cabin to a desired temperature.

[0059] The heat medium HM heated by the refrigerant RF in the condenser 12 is guided to the second indoor air-conditioning heat exchanger inlet pipe L3 through the condenser pipe L1 and the flow path junction C by the action of the first pump 21. The heat medium HM then passes through the second indoor air-conditioning heat exchanger 25c and the outdoor heat exchanger 23 and is guided to the three-way valve 26. The heat medium HM guided to the circulation flow path 24 exchanges heat with outside air guided from the outdoor heat exchanger fan 23a in the outdoor heat exchanger 23 and dissipates heat. The heat medium HM cooled by dissipating heat passes through the three-way valve 26 and is guided to the condenser 12. In this way, in the cooling mode, the heat medium HM is circulated between the condenser 12 and the outdoor heat exchanger 23 by the first pump 21.

[0060] The temperature adjustment system 100 of the present embodiment described above has the following actions and effects. According to the temperature adjustment system 100 of the present embodiment, by executing the first heater mode, the heat medium HM branches into the condenser pipe L1 and the evaporator pipe L5 at the three-way valve 26, which is located downstream in the flow direction of the heat medium HM from the indoor air-conditioning unit 25 that heats or cools the air, and the heat medium HM that has passed through the condenser pipe L1 and the evaporator pipe L5 joins at the flow path junction C. The joined heat medium HM is pressure-fed to the indoor air-conditioning unit 25 by the first pump 21, which is located downstream in the flow direction from the flow path junction C.

[0061] All of the heat medium HM discharged from the first pump 21 is guided to the indoor air-conditioning unit 25, which heats or cools the air. Therefore, the temperature difference of the heat medium HM required to heat the air to a desired temperature can be reduced compared to when only a portion of the heat medium HM discharged from the first pump 21 is guided to the indoor air-conditioning unit 25. Therefore, the thermal efficiency can be improved when the first heater mode, which heats the air using the power of the compressor 11, is executed.

[0062] According to the temperature control system 100 of this embodiment, the air can be adjusted to a desired temperature by adjusting the first flow rate of the heat medium HM led to the condenser pipe L1 using the three-way valve 26 and the second flow rate of the heat medium HM led to the evaporator pipe L5.

[0063] According to the temperature control system 100 of this embodiment, by adjusting the first flow rate and the second flow rate based on the pressure and / or temperature of the refrigerant RF flowing into the evaporator 14, fluctuations in the flow rate of the heat medium HM flowing into the indoor air conditioning unit 25 can be suppressed, and the air can be maintained at a desired temperature.

[0064] According to the temperature control system 100 of this embodiment, when the pressure of the refrigerant RF flowing into the evaporator 14 is reduced, the second flow rate is reduced and the first flow rate is increased, thereby preventing the flow rate of the heat medium HM circulating through the second indoor air conditioning heat exchanger 25c from decreasing excessively, thereby suppressing fluctuations in the temperature of the air flowing out of the indoor air conditioning unit 25.

[0065] According to the temperature control system 100 of this embodiment, by adjusting the first flow rate and the second flow rate based on the pressure and / or temperature of the refrigerant RF flowing into the condenser 12, fluctuations in the flow rate of the heat medium HM flowing into the indoor air conditioning unit 25 can be suppressed, and the air can be maintained at a desired temperature.

[0066] According to the temperature control system 100 of this embodiment, when the pressure of the refrigerant RF flowing into the condenser 12 is reduced, the first flow rate is increased and the second flow rate is decreased, thereby suppressing an excessive increase in the flow rate of the heat medium HM circulating through the second indoor air conditioning heat exchanger 25c, which would otherwise cause fluctuations in the temperature of the air flowing out of the indoor air conditioning unit 25.

[0067] According to the temperature control system 100 of this embodiment, when the heat pump mode is executed, the three-way valve 26 guides the heat medium HM from the second indoor air conditioning heat exchanger outlet pipe L6 to the condenser pipe L1, and the three-way valve 28 guides the heat medium HM that has passed through the condenser pipe L1 to the indoor air conditioning unit 25, thereby forming a first circulation system, and the three-way valves 27 and 28 guide the heat medium HM from the evaporator pipe L5 to the circulation flow path 24, thereby forming a second circulation system.

[0068] When the heat pump mode is executed, the heat medium HM circulating through the first circulation system and the heat medium HM circulating through the second circulation path do not mix, so that a decrease in thermal efficiency caused by heat exchange between the heat medium HM due to mixing can be suppressed. Furthermore, when the first heater mode is executed, the second pump 22 that pumps the heat medium HM to the outdoor heat exchanger 23 is disposed in the circulation flow path 24, so that the heat medium HM circulating through the evaporator pipe L5 does not flow through the second pump 22. Therefore, in the first heater mode, a decrease in thermal efficiency caused by the heat medium HM passing through the second pump 22 can be suppressed.

[0069] According to the temperature control system 100 of this embodiment, the reserve tank 29 is positioned downstream of the branch position B in the flow direction, so that the suction pressure of the first pump 21 can be prevented from becoming negative and forming a negative pressure area in the heat medium circuit 20.

[0070] According to the temperature control system 100 of this embodiment, the reserve tank 29 is positioned closer to the flow path junction C than the branch position B, so that the suction pressure of the first pump 21 can be more reliably prevented from becoming negative pressure.

[0071] The temperature regulation system and the control method for the temperature regulation system described in each of the above-described embodiments can be understood, for example, as follows.

[0072] A temperature control system according to a first aspect of the present disclosure includes a refrigerant circuit (10) in which a refrigerant circulates through a compressor (11), a high-pressure side heat exchanger (12), a pressure reducing section (13), and a low-pressure side heat exchanger (14), a heat medium circuit (20) in 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, and a control section (30) that controls the refrigerant circuit and the heat medium circuit, wherein the heat medium circuit includes a temperature control device (25) that heats a temperature control target using the heat medium, and a flow path branching section (26) that is arranged downstream of the temperature control device in the flow direction and branches the heat medium into at least one of a first heat medium flow path (L1) that guides the heat medium to the high-pressure side heat exchanger and a second heat medium flow path (L5) that guides the heat medium to the low-pressure side heat exchanger. a flow path junction (27) that is arranged upstream of the temperature adjustment device in the flow direction and that joins the heat medium flowing through the first heat medium flow path and the heat medium flowing through the second heat medium flow path, and a first pump (21) that is arranged upstream of the flow path branching section in the flow direction and downstream of the flow path junction in the flow direction and that pressurizes the heat medium along the flow direction, and the control unit controls the flow path branching section, the flow path junction, and the first pump to execute a heater mode in which the heat medium is branched into the first heat medium flow path and the second heat medium flow path at the flow path branching section, and the heat medium that has passed through the first heat medium flow path and the second heat medium flow path is joined at the flow path junction and led to the temperature adjustment device.

[0073] In the temperature control system according to the first aspect of the present disclosure, when the temperature control mode is executed, the heat medium branches into a first heat medium flow path and a second heat medium flow path at a flow path branching section located downstream in the heat medium flow direction from a temperature control device that heats a temperature control target, and the heat medium that has passed through the first heat medium flow path and the second heat medium flow path merges at a flow path junction. The merged heat medium is pumped to the temperature control device by a first pump located downstream in the flow direction from the flow path junction.

[0074] All of the heat medium discharged from the first pump is guided to the temperature control device that heats the temperature control target. Therefore, the temperature difference of the heat medium required to heat the temperature control target to a desired temperature can be reduced compared to when only a portion of the heat medium discharged from the first pump is guided to the temperature control device. Therefore, the thermal efficiency can be improved when executing the temperature control mode that uses the power of the compressor to heat the temperature control target.

[0075] A temperature adjustment system according to a second aspect of the present disclosure is the same as the first aspect, but further includes the following configuration: the flow path branching section is configured to be able to adjust a first flow rate of the heat medium guided to the first heat medium flow path and a second flow rate of the heat medium guided to the second heat medium flow path.

[0076] According to the temperature control system of the second aspect of the present disclosure, the temperature of the object to be temperature controlled can be adjusted to a desired temperature by adjusting the first flow rate of the heat medium guided to the first heat medium flow path at the flow path branching section and the second flow rate of the heat medium guided to the second heat medium flow path.

[0077] The temperature adjustment system according to a third aspect of the present disclosure is the second aspect, further including the following configuration: That is, the control unit controls the flow path branching unit to adjust the first flow rate and the second flow rate based on the pressure and / or temperature of the refrigerant flowing into the low-pressure side heat exchanger.

[0078] According to the temperature control system of the third aspect of the present disclosure, by adjusting the first flow rate and the second flow rate based on the pressure and / or temperature of the refrigerant flowing into the low-pressure side heat exchanger, fluctuations in the flow rate of the heat medium flowing into the temperature control equipment can be suppressed, and the temperature control target can be maintained at the desired temperature.

[0079] A temperature adjustment system according to a fourth aspect of the present disclosure is the third aspect, further including the following configuration: That is, when the pressure of the refrigerant flowing into the low-pressure side heat exchanger is reduced, the control unit controls the flow path branching unit to reduce the second flow rate.

[0080] According to the temperature control system of the fourth aspect of the present disclosure, by reducing the second flow rate and increasing the first flow rate when lowering the pressure of the refrigerant flowing into the low-pressure side heat exchanger, the flow rate of the heat medium circulating through the second indoor heat exchanger can be prevented from decreasing excessively, thereby suppressing fluctuations in the temperature of the air flowing out of the temperature control equipment.

[0081] The temperature adjustment system according to the fifth aspect of the present disclosure is the second aspect, further including the following configuration: That is, the control unit controls the flow path branching unit to adjust the first flow rate and the second flow rate based on the pressure and / or temperature of the refrigerant flowing into the high-pressure side heat exchanger.

[0082] According to the temperature control system of the fifth aspect of the present disclosure, by adjusting the first flow rate and the second flow rate based on the pressure and / or temperature of the refrigerant flowing into the high-pressure side heat exchanger, fluctuations in the flow rate of the heat medium flowing into the temperature control equipment can be suppressed, and the temperature of the object to be temperature controlled can be maintained at the desired temperature.

[0083] A temperature adjustment system according to a sixth aspect of the present disclosure is the fifth aspect, further including the following configuration: That is, when the pressure of the refrigerant flowing into the high-pressure side heat exchanger is reduced, the control unit controls the flow path branching unit to increase the first flow rate.

[0084] According to the temperature control system of the sixth aspect of the present disclosure, by increasing the first flow rate and decreasing the second flow rate when lowering the pressure of the refrigerant flowing into the high-pressure side heat exchanger, it is possible to suppress fluctuations in the temperature of the air flowing out of the temperature control equipment, which would otherwise occur if the flow rate of the heat medium circulating through the second indoor heat exchanger were to increase excessively.

[0085] A temperature control system according to a seventh aspect of the present disclosure is the first or second aspect, further comprising the following configuration: That is, the heat medium circuit includes a circulation flow path (24) that branches the heat medium from the second heat medium flow path downstream of the low-pressure side heat exchanger in the flow direction and causes the heat medium to flow into the second heat medium flow path upstream of the low-pressure side heat exchanger in the flow direction, an outdoor heat exchanger (23) that is arranged in the circulation flow path and exchanges heat between outside air and the heat medium, a flow path switching unit (27, 28) that switches between a circulation state in which the heat medium flows through the circulation flow path and a non-circulation state in which the heat medium does not flow through the circulation flow path, and and a second pump (22) arranged in the circulation flow path and pressurizing the heat medium from the second heat medium flow path to the outdoor heat exchanger, wherein the control unit controls the flow path branching unit, the flow path switching unit, the first pump, and the second pump to execute a heat pump mode in which a first circulation system is formed by guiding the heat medium to the first heat medium flow path at the flow path branching unit, and a second circulation system is formed by guiding the heat medium from the second heat medium flow path to the circulation flow path at the flow path switching unit in the circulation state.

[0086] According to the temperature control system of the seventh aspect of the present disclosure, when the heat pump mode is executed, a first circulation system is formed by guiding the heat medium that has passed through the first heat medium flow path to the temperature control device at the flow path junction, and a second circulation system is formed by guiding the heat medium from the second heat medium flow path to the circulation flow path at the flow path switching unit in the circulation state.

[0087] When the heat pump mode is executed, the heat medium circulating through the first circulation system and the heat medium circulating through the second circulation path do not mix, so that a decrease in thermal efficiency caused by heat exchange between the heat mediums due to mixing can be suppressed. Furthermore, when the temperature control mode is executed, the second pump that pumps the heat medium to the outdoor heat exchanger is disposed in the circulation path, so that the heat medium circulating through the second heat medium path does not pass through the second pump. Therefore, in the temperature control mode, a decrease in thermal efficiency caused by the heat medium passing through the second pump can be suppressed.

[0088] A temperature control system according to an eighth aspect of the present disclosure is the seventh aspect, further including the following configuration: the heat medium circuit includes a reserve tank that is arranged downstream of a branch position (B) from the second heat medium flow path to the circulation flow path in the flow direction and that stores the heat medium.

[0089] According to the temperature control system of the eighth aspect of the present disclosure, the reserve tank is positioned downstream of the branching position in the flow direction, thereby preventing the suction pressure of the first pump from becoming negative and forming a negative pressure area in the heat medium circuit.

[0090] A temperature regulation system according to a ninth aspect of the present disclosure is the eighth aspect, further including the following configuration: the reserve tank is disposed at a position closer to the flow path junction than the branch position.

[0091] According to the temperature control system of the ninth aspect of the present disclosure, the reserve tank is positioned closer to the flow path junction than the branch position, thereby more reliably preventing the suction pressure of the first pump from becoming negative.

[0092] In a control method for a temperature adjustment system according to a tenth aspect of the present disclosure, the temperature adjustment system includes a refrigerant circuit in which a refrigerant circulates through a compressor, a high-pressure side heat exchanger, a pressure reducing unit, and a low-pressure side heat exchanger, and a heat medium circuit in 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, the heat medium circuit including a temperature adjustment device that heats an object to be temperature adjusted using the heat medium, a flow path branching unit that is arranged downstream of the temperature adjustment device in the flow direction and that branches the heat medium into at least one of a first heat medium flow path that leads the heat medium to the high-pressure side heat exchanger and a second heat medium flow path that leads the heat medium to the low-pressure side heat exchanger, and a flow path branching unit that is arranged upstream of the temperature adjustment device in the flow direction. the heat medium flowing through the first heat medium flow path and the heat medium flowing through the second heat medium flow path; and a first pump arranged upstream of the flow path branching section in the flow direction and downstream of the flow path junction in the flow direction, the first pump pressurizing the heat medium along the flow direction, the heat medium being branched into the first heat medium flow path and the second heat medium flow path at the flow path branching section, and the heat medium having passed through the first heat medium flow path and the second heat medium flow path being joined at the flow path junction and being guided to the temperature adjustment device.

[0093] According to the control method for a temperature adjustment system according to a tenth aspect of the present disclosure, by executing a temperature adjustment mode, the heat medium branches into a first heat medium flow path and a second heat medium flow path at a flow path branching section located downstream in the flow direction of the heat medium from a temperature adjustment device that heats a temperature adjustment target, and the heat medium that has passed through the first heat medium flow path and the second heat medium flow path merges at a flow path junction. The merged heat medium is pumped to the temperature adjustment device by a first pump located downstream in the flow direction from the flow path junction.

[0094] All of the heat medium discharged from the first pump is guided to the temperature control device that heats the temperature control target. Therefore, the temperature difference of the heat medium required to heat the temperature control target to a desired temperature can be reduced compared to when only a portion of the heat medium discharged from the first pump is guided to the temperature control device. Therefore, the thermal efficiency can be improved when executing the temperature control mode that uses the power of the compressor to heat the temperature control target.

[0095] REFRIGERATION VALVE 10 Refrigerant circuit 11 Compressor 12 Condenser 13 Expansion valve 14 Evaporator 15 Expansion valve 20 Heat medium circuit 21 First pump 22 Second pump 23 Outdoor heat exchanger 23a Outdoor heat exchanger fan 24 Circulation flow path 25 Indoor air conditioning unit (temperature control device) 25a Indoor air conditioning fan 25b First indoor air conditioning heat exchanger 25c Second indoor air conditioning heat exchanger 26 Three-way valve (flow path branching portion) 27 Three-way valve (flow path switching portion) 28 Three-way valve (flow path switching portion) 29 Reserve tank 30 Control unit 100 Temperature control system B Branching position C Flow path junction HM Heat medium L1 Condenser piping (first heat medium flow path) L2 First pump inlet piping L3 Second indoor air conditioning heat exchanger inlet piping L5 Evaporator piping (second heat medium flow path) L6 Second indoor air conditioning heat exchanger outlet piping RF Refrigerant

Claims

a heat medium circuit through which a heat medium circulates to exchange heat with the refrigerant in the high-pressure side heat exchanger and the low-pressure side heat exchanger; and a control unit for controlling the refrigerant circuit and the heat medium circuit, wherein the heat medium circuit has: a temperature control device that heats a temperature control target using the heat medium; a flow path branching section that is arranged downstream of the temperature control device in a flow direction of the heat medium and branches the heat medium into at least one of a first heat medium flow path that leads to the high-pressure side heat exchanger and a second heat medium flow path that leads to the low-pressure side heat exchanger; a flow path junction that is arranged upstream of the temperature control device in the flow direction and merges the heat medium flowing through the first heat medium flow path and the heat medium flowing through the second heat medium flow path; and a first pump that is arranged upstream of the flow path branching section in the flow direction and downstream of the flow path junction in the flow direction to pump the heat medium along the flow direction, The control unit controls the flow path branching unit, the flow path junction, and the first pump so as to execute a temperature control mode in which the heat medium is branched into the first heat medium flow path and the second heat medium flow path at the flow path branching unit, and the heat medium that has passed through the first heat medium flow path and the second heat medium flow path is joined at the flow path junction to be guided to the temperature control device.

2. A temperature control system as described in claim 1, wherein the flow path branching portion is configured to be able to adjust a first flow rate of the heat medium guided to the first heat medium flow path and a second flow rate of the heat medium guided to the second heat medium flow path.

3. A temperature control system as described in claim 2, wherein the control unit controls the flow path branching section to adjust the first flow rate and the second flow rate based on the pressure and / or temperature of the refrigerant flowing into the low-pressure side heat exchanger.

4. A temperature control system as described in claim 3, wherein the control unit controls the flow path branching portion so as to reduce the second flow rate when the pressure of the refrigerant flowing into the low-pressure side heat exchanger is reduced.

5. A temperature control system as described in claim 2, wherein the control unit controls the flow path branching section to adjust the first flow rate and the second flow rate based on the pressure and / or temperature of the refrigerant flowing into the high-pressure side heat exchanger.

6. A temperature control system as described in claim 5, wherein the control unit controls the flow path branching portion so as to increase the first flow rate when the pressure of the refrigerant flowing into the high-pressure side heat exchanger is reduced.

7. The heat medium circuit has: a circulation flow path that branches the heat medium from the second heat medium flow path downstream of the low-pressure side heat exchanger in the flow direction and causes the heat medium to flow into the second heat medium flow path upstream of the low-pressure side heat exchanger in the flow direction; an outdoor heat exchanger that is arranged in the circulation flow path and exchanges heat between outside air and the heat medium; a flow path switching unit that switches between a circulation state in which the heat medium flows through the circulation flow path and a non-circulation state in which the heat medium does not flow through the circulation flow path; and a second pump that is arranged in the circulation flow path and pressure-feeds the heat medium from the second heat medium flow path to the outdoor heat exchanger, 3. The temperature adjustment system according to claim 1, wherein the control unit controls the flow path branching unit, the flow path switching unit, the first pump, and the second pump to execute a heat pump mode in which a first circulation system is formed by guiding the heat medium to the first heat medium flow path at the flow path branching unit, and a second circulation system is formed by guiding the heat medium from the second heat medium flow path to the circulation flow path at the flow path switching unit in the circulation state.

8. A temperature control system as described in claim 7, wherein the heat medium circuit is arranged downstream of a branching position from the second heat medium flow path to the circulation flow path in the flow direction and has a reserve tank for storing the heat medium.

9. The temperature adjustment system according to claim 8, wherein the reserve tank is disposed at a position closer to the flow path junction than the branching position.

10. A method for controlling a temperature adjustment system, the temperature adjustment system comprising: a refrigerant circuit in which a refrigerant circulates through a compressor, a high-pressure side heat exchanger, a pressure reducing section, and a low-pressure side heat exchanger; and a heat medium circuit in which a heat medium circulates to exchange heat with the refrigerant in the high-pressure side heat exchanger and the low-pressure side heat exchanger, the heat medium circuit comprising: a temperature adjustment device that heats a temperature adjustment target using the heat medium; a flow path branching section that is arranged downstream of the temperature adjustment device in a flow direction of the heat medium and branches the heat medium into at least one of a first heat medium flow path that leads to the high-pressure side heat exchanger and a second heat medium flow path that leads to the low-pressure side heat exchanger; and a flow path junction section that is arranged upstream of the temperature adjustment device in the flow direction and causes the heat medium flowing through the first heat medium flow path and the heat medium flowing through the second heat medium flow path to join together. a first pump that is arranged upstream of the flow path branching portion in the flow direction and downstream of the flow path junction in the flow direction and pressurizes the heat medium along the flow direction, wherein the control method includes a control step of controlling the flow path branching portion and the first pump so as to execute a heater mode in which the heat medium is branched into the first heat medium flow path and the second heat medium flow path at the flow path branching portion, and the heat medium that has passed through the first heat medium flow path and the second heat medium flow path is joined at the flow path junction to be guided to the temperature adjustment device.

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