Temperature control system and temperature control method for vehicle

Abstract

The present invention ensures heating capacity even when it is difficult to ensure a heat source due to a low outside temperature. The vehicle temperature control system includes a refrigerant circuit and a heat medium circuit. The heat medium loop comprises a high-pressure side heat exchanger, a low-pressure side heat exchanger, a pump, an outdoor heat exchanger, temperature control equipment and an outdoor bypass path. The temperature control system is provided with a power heat source mode in which the heat medium flowing out of the high-pressure-side heat exchanger flows into the low-pressure-side heat exchanger via the temperature control device and then flows into the high-pressure-side heat exchanger via the outdoor bypass path, and the power of the compressor and the power of the pump are used as heat sources. The control device is configured so as to be able to change the rotational speed of the pump to at least a first rotational speed and a second rotational speed, and so as to be able to set the pump with a second rotational speed, which is greater than the first rotational speed set to the pump in the other operation modes, in the power heat source mode.

Description

Technical Field

[0001] The invention relates to a temperature control system assembled on a vehicle and a temperature control method using the temperature control system. Background Art

[0002] In electric vehicles and hybrid vehicles that obtain driving force for the vehicle from engines and motors, when the heat source is easily insufficient, in addition to the air conditioning functions required by the vehicle, such as heating and cooling, dehumidification, and ventilation, thermal management and waste heat utilization of vehicle-mounted equipment such as batteries are required. In the past, in addition to heat pump systems, multiple systems have been used to meet such requirements, such as systems including a cooler for cooling the battery and a heater for heating the battery, or systems that use a pump to transport water heated by waste heat from a radiator to a temperature control target.

[0003] As a vehicle thermal management system that can integrate the thermal management of air conditioning and equipment, a system has been proposed, which includes: a primary circuit in which the refrigerant circulates according to a refrigeration cycle; and a secondary circuit in which a heat medium (water, etc.) that performs heat exchange with the refrigerant in the primary circuit is transported to the vehicle-mounted equipment by a pump (for example, Patent Document 1).

[0004] The thermal management system described in Patent Document 1 includes: a first heating medium circuit, which is equipped with an evaporator of a refrigerant circuit and a heating medium external air heat exchanger; and a second heating medium circuit, which is equipped with a condenser of a refrigerant circuit and a heater core of a machine room air conditioning unit. The first heating medium circuit and the second heating medium circuit are switched between a non-connected state (non-connected mode) and a connected state (connected mode) assuming a low outside temperature by switching the flow paths of the first switching mechanism and the second switching mechanism.

[0005] In the non-connected mode, a heat pump operation is performed to extract heat from the outside air to the heat medium of the second heat medium circuit. In the connected mode, the heat medium flowing out of the evaporator does not flow into the heat medium outside air heat exchanger, but merges with the heat medium flowing out of the condenser, and the heat medium flows into the evaporator and the condenser in parallel. At this time, the first heat medium circuit and the second heat medium circuit are connected via the evaporator and the condenser. Previous technical literature Patent Literature

[0006] Patent Document 1: Patent No. 6083304 Summary of the invention Technical issues to be solved by the invention

[0007] In the connection mode of Patent Document 1, the heating medium flowing out of the evaporator and the heating medium flowing out of the condenser are mixed, and the temperature becomes the middle temperature of the temperature of each heating medium before mixing, and flows into the evaporator and the condenser. Therefore, it takes time for the temperature of the heating medium flowing out of the condenser to rise compared with the non-connection mode. In addition, since the flow rate of the heating medium flowing into the indoor heat exchanger is reduced, the heating capacity has room for improvement.

[0008] An object of the present invention is to provide a temperature control system and a temperature control method for a vehicle, which can ensure heating capacity even when it is difficult to ensure a heat source due to low external temperature. Means for solving technical problems

[0009] The present invention is a temperature control system for a vehicle, which comprises: a refrigerant circuit, including a compressor, a high-pressure side heat exchanger, a pressure reducing unit and a low-pressure side heat exchanger, configured so that the refrigerant can circulate according to a refrigeration cycle; and a heat carrier circuit, configured so that a heat carrier that performs heat exchange with the refrigerant can circulate. The heat carrier circuit includes: a high-pressure side heat exchanger, which allows the refrigerant to exchange heat with the heat carrier; a low-pressure side heat exchanger, which allows the refrigerant to exchange heat with the heat carrier; a pump, which is configured to pressurize the heat carrier; an outdoor heat exchanger, which allows the external air to exchange heat with the heat carrier; a temperature control device, which is equivalent to a temperature control object heated or cooled by the heat carrier, or is used for heating or cooling the temperature control object; and an outdoor bypass path, which allows the heat carrier to bypass the outdoor heat exchanger. The temperature control system has a power heat source mode as an operating mode. The power heat source mode is a mode in which the heat carrier flowing out of the high-pressure side heat exchanger flows into the low-pressure side heat exchanger via the temperature control device, and then flows into the high-pressure side heat exchanger through the outdoor bypass path. This mode utilizes the power of the compressor and the power of the pump as heat sources, and has a control device that is configured to set the speed of the pump to be variable. The control device is configured to change the rotation speed of the pump to at least a first rotation speed and a second rotation speed, and to set the second rotation speed, which is higher than the first rotation speed set to the pump in other operation modes, to the pump in the power heat source mode.

[0010] Furthermore, the present invention can also be extended to a temperature control method for a vehicle. Effects of the Invention

[0011] According to the present invention, even if the temperature control system of a vehicle is prone to insufficient heat source, and under the condition that the heat absorption from the outside air is insufficient due to the outside temperature being significantly lower than 0°C, the insufficient heat source can be compensated by increasing the power of the pump in the power heat source mode, thereby ensuring the heating capacity.

[0012] In the power heat source mode, since the high-pressure side heat exchanger and the low-pressure side heat exchanger are connected in series, the temperature of the heat medium flowing out of the high-pressure side heat exchanger can be increased more quickly than when the heat medium flows into the high-pressure side heat exchanger and the low-pressure side heat exchanger in parallel. In addition, since the circulation amount of the heat medium in the temperature control device is large, the heat exchange amount between the heat medium and the temperature control object becomes larger. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 1 is a circuit diagram (heat pump mode) showing a vehicle temperature control system according to an embodiment of the present invention. Figure 2 Yes means Figure 1 A diagram of the operating status of the system based on the heater mode. Figure 3 This is a block diagram showing the hardware configuration of the control device. Figure 4 It is a schematic diagram of the pH line diagram when the outside temperature is low. Figure 5 It is a graph showing the relationship between the low pressure and the compressor power of the refrigerant circuit in the heater mode (low pressure-compressor power characteristics). Figure 6 1 is a circuit diagram showing a vehicle temperature control system according to a fifth modified example of the present invention (start-up heater mode). DETAILED DESCRIPTION

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings. [Implementation Method] Figure 1 The vehicle temperature control system 1 shown is installed in, for example, a vehicle not shown in the figure, such as an electric vehicle that does not have an engine but obtains the driving force for the vehicle from an electric motor for driving, or a so-called hybrid vehicle that obtains the driving force for the vehicle from an engine and an electric motor. In addition to being responsible for air conditioning functions such as heating and cooling, dehumidification, and ventilation of the cabin 8 where passengers sit, the temperature control system 1 is also responsible for thermal management and waste heat recovery of vehicle-mounted devices such as a battery device (power supply device), a driving motor, and heat-generating electronic devices mounted on the vehicle. The act of adjusting to an appropriate temperature or humidity, or managing the vehicle-mounted devices to an appropriate temperature is collectively referred to as "thermal management." The vehicle temperature control system 1 and other electric devices or electronic devices provided in the vehicle-mounted devices are supplied with electric power stored in the vehicle-mounted battery device. The vehicle-mounted battery device is charged from an external power supply when the vehicle is stopped.

[0015] 〔Overall structure〕 The temperature control system 1 comprises: a refrigerant circuit 10, which is configured to allow the refrigerant to circulate; a heat medium circuit 20, which is configured to allow the heat medium that performs heat exchange with the refrigerant to circulate; and a control device 5, which sets the temperature control system 1 to a specified operating mode and controls the operating state of the temperature control system 1 according to the operating mode. In addition, the temperature control system 1 includes sensors such as an outdoor temperature sensor 61 for detecting the outdoor temperature, a temperature sensor 62 for detecting the temperature of the air-conditioned air blown into the machine room 8, a low-pressure pressure sensor 63 for detecting the low pressure pL of the refrigerant circuit 10, a high-pressure pressure sensor 64 for detecting the high pressure pH of the refrigerant circuit 10, and a heat medium temperature sensor 65 for detecting the temperature of the heat medium.

[0016] The temperature control system 1 has a plurality of operation modes selected by the occupant or the control device 5. The temperature control system 1 has the following characteristics: in the heater mode HT ( Figure 2 ), the power of the pumps 21 and 22 for pressurizing the heating medium is used as a heat source. In addition to the heater mode HT, the heat pump mode HP ( Figure 1 ). Heater mode HT is suitable for situations where the outside temperature is lower than heat pump mode HP.

[0017] 〔Refrigerant circuit structure〕 like Figure 1 As shown in an example of the configuration in FIG. 1 , the refrigerant circuit 10 includes a compressor 11, a condenser 12, an expansion valve 13, and an evaporator 14. In the refrigerant circuit 10, the refrigerant circulates according to a refrigeration cycle. As the refrigerant sealed in the refrigerant circuit 10, a known appropriate single refrigerant or mixed refrigerant can be used. For example, as the refrigerant of this embodiment, HFC (Hydro Fluoro Carbon: hydrofluorocarbon) refrigerants such as R410A and R32, HFO (Hydro Fluoro Olefin: hydrofluoroolefin) refrigerants such as R1234ze and R1234yf, or hydrocarbon (HC: Hydrocarbon: hydrocarbon) refrigerants such as propane and isobutane can be used. In particular, as the refrigerant of this embodiment, R1234yf is preferably used.

[0018] When the above-mentioned fluorine-based or hydrocarbon-based refrigerants are used, a subcritical refrigeration cycle is constructed 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 transition critical refrigeration cycle is formed in which the refrigerant pressure on the high-pressure side exceeds the critical pressure of the refrigerant. Even in this case, the following effect can be obtained, that is, the refrigerant dissipates heat through the high-pressure side heat exchanger as in the condenser 12 of the present embodiment, and the refrigerant absorbs heat through the low-pressure side heat exchanger as in the evaporator 14 of the present embodiment, so a refrigerant that forms a transition critical refrigeration cycle such as the carbon dioxide refrigerant can also be adopted in the refrigerant circuit 10.

[0019] The compressor 11 corresponds to an electric compressor including a motor driven by electric power supplied from a battery device (not shown). The compressor 11 adiabatically compresses the refrigerant sucked into a casing (not shown) by a compression mechanism and discharges the refrigerant. In the heater mode HT, the power of the compressor 11 becomes a heat source. In this case, the compressor 11 is an electric compressor, in which case the motor and the main body of the compressor (compressor body) constitute a heat source. That is, if the motor is powered, heat is generated by copper loss, iron loss and mechanical loss, and the compressor body generates heat according to the theory of adiabatic compression and the Ball-Charles law, thereby being able to become a heat source. In addition, in the compressor 11, heat is applied to the refrigerant passing through the compressor body.

[0020] The condenser 12 exchanges heat between the refrigerant gas discharged from the compressor 11 and a heating medium. The expansion valve 13 (decompression unit) adiabatically expands the refrigerant flowing out of the condenser 12 by decompressing the refrigerant. As the expansion valve 13, a temperature-type expansion valve can be used in addition to an electronic expansion valve whose opening can be controlled according to a command from the control device 5. Alternatively, a capillary tube can be used instead of the expansion valve 13.

[0021] The evaporator 14 exchanges heat between the refrigerant flowing out of the expansion valve 13 and a heating medium. The refrigerant evaporated by the evaporator 14 is sucked into the compressor 11. An accumulator (gas-liquid separator) (not shown) may be provided between the evaporator 14 and the compressor 11 .

[0022] A relatively high refrigerant pressure (high pressure pH) is applied to the condenser 12, and a relatively low refrigerant pressure (low pressure pL) is applied to the evaporator 14. The refrigerant circulates in the refrigerant circuit 10 based on the pressure difference between the high pressure pH and the low pressure pL. exist Figure 1 In FIG. 1 , the flow of the refrigerant on the low-pressure side is indicated by a thick solid line, and the flow of the refrigerant on the high-pressure side is indicated by a thick dotted line. Figure 2 Same.

[0023] 〔Structure of the heat carrier circuit〕 The heat medium circuit 20 is configured so that a heat medium capable of exchanging heat with the refrigerant can circulate through the condenser 12 and the evaporator 14. The heat medium is used to cool or heat at least one temperature control object. One of the temperature control objects in this embodiment corresponds to the air in the machine room 8. The heating medium sealed in the heating medium circuit 20 is a liquid such as water or salt water that is maintained in a liquid phase and circulated in the heating medium circuit 20. Examples of the salt water include a mixed liquid of water and propylene glycol or a mixed liquid of water and ethylene glycol.

[0024] like Figure 1 As shown in an example of the structure, the heat medium circuit 20 includes a condenser 12, an evaporator 14, a first pump 21 and a second pump 22, an outdoor heat exchanger 23, an outdoor bypass path 24, an indoor heat exchanger 25, and a first switching valve 31, a second switching valve 32 and a third switching valve 33 as multiple flow path switching valves. The first pump 21 and the second pump 22 also have a motor as a power source and a pump body as a pressure-increasing unit, and each generates heat in the same manner as the compressor 11, and thus can serve as a heat source. In addition, the first pump 21 and the second pump 22 apply heat to the heat medium passing through the first pump 21 and the second pump 22.

[0025] In this embodiment, the first switching valve 31 and the second switching valve 32 are four-way valves, and the third switching valve 33 is equivalent to a three-way valve. Figure 1 In the heat pump mode HP shown, both the heating medium flowing out of the condenser 12 and the heating medium flowing out of the evaporator 14 flow through the first switching valve 31 .

[0026] The heat medium circuit 20 is provided with a liquid storage tank 15 as a mechanism for bringing the suction side of the pumps 21 and 22 to atmospheric pressure. According to the liquid storage tank 15, even if the pressure of the heat medium increases due to volume expansion caused by the temperature increase of the heat medium, the suction side of the pumps 21 and 22 is maintained at atmospheric pressure, so that the heat medium can be stably pressure-fed by the pumps 21 and 22. Liquid storage tanks may be provided on the suction sides of the pumps 21 and 22, respectively, but only one liquid storage tank 15 connected to the pipes 401 and 402 may be provided. An on-off valve 17 for connecting only one of the pipes 401 and 402 to the liquid storage tank 15 may be provided on the communication path 16 connecting the pipes 401 and 402 to the liquid storage tank 15. By closing the on-off valve 17 when the series circuit CC described later is used, it is possible to prevent the heat medium from moving due to the pressure difference through the communication path 16.

[0027] The heating medium circuit 20 preferably includes a condenser bypass path 12A for bypassing the heating medium from the condenser 12 , and a condenser flow rate regulating valve 12V. The condenser flow rate regulating valve 12V adjusts the flow rate ratio of the heating medium in the condenser 12 and the condenser bypass path 12A according to a control command issued from the control device 5 .

[0028] exist Figure 1 In the example shown, due to the flow rate adjustment by the condenser flow rate adjustment valve 12V, the entire amount of the heating medium flowing from the first switching valve 31 toward the condenser 12 does not flow into the condenser bypass path 12A but flows into the condenser 12 .

[0029] Furthermore, the heating medium circuit 20 preferably includes an evaporator bypass path 14A for bypassing the heating medium from the evaporator 14 , and an evaporator flow rate regulating valve 14V configured to be able to adjust a flow rate ratio between the evaporator 14 and the evaporator bypass path 14A. The evaporator flow rate regulating valve 14V adjusts the flow rate ratio of the heating medium in the evaporator 14 and the evaporator bypass path 14A according to a control command issued from the control device 5 .

[0030] exist Figure 1 In the example shown, due to the flow rate adjustment by the evaporator flow rate adjustment valve 14V, the entire amount of the heating medium flowing from the first switching valve 31 toward the evaporator 14 flows into the evaporator 14 without flowing into the evaporator bypass path 14A.

[0031] The condenser flow rate regulating valve 12V, which is a three-way valve in the present embodiment, can be replaced by two two-way valves capable of regulating the flow rate, or a single two-way valve capable of regulating the flow rate. For example, one two-way valve can be arranged on the condenser bypass path 12A, and the other two-way valve can be arranged on the piping between the condenser flow rate regulating valve 12V and the condenser 12. Alternatively, a single two-way valve can be arranged on one side of the condenser bypass path 12A and the piping. The evaporator flow rate regulating valve 14V can also be replaced with two two-way valves capable of regulating the flow rate, or a single two-way valve capable of regulating the flow rate, similarly to the above.

[0032] The first pump 21 and the second pump 22 are both electric pumps driven by a motor (not shown). The first pump 21 pumps the heating medium flowing out of the evaporator 14 and discharges it to pressurize the heating medium. The second pump 22 pumps the heating medium flowing out of the condenser 12 and discharges it to pressurize the heating medium.

[0033] As the pumps 21 and 22 , a well-known centrifugal pump or a positive displacement pump can be appropriately adopted.

[0034] At least one of the first pump 21 and the second pump 22 is configured to variably control the rotation speed N of the mechanism for pressurizing the heat medium by a drive circuit portion that applies a drive current to the motor. In the present embodiment, the rotation speed N of both the first pump 21 and the second pump 22 is variably controlled.

[0035] The positions of the first pump 21 and the second pump 22 are not limited to the illustrated examples, and may be appropriately determined within a range where the heating medium can be pressure-fed by at least one of the first pump 21 and the second pump 22 in consideration of the heating medium path in each operation mode.

[0036] The outdoor heat exchanger 23 exchanges heat between the outside air outside the machine room 8 and the heat medium. The outdoor heat exchanger 23 is equivalent to a radiator arranged near the air inlet of the vehicle, for example. The outside air supplied to the outdoor heat exchanger 23 by the running of the vehicle and the operation of the outdoor blower 23A dissipates or absorbs heat according to the temperature difference between the outside air and the heat medium.

[0037] The outdoor bypass path 24 allows the heating medium to bypass the outdoor heat exchanger 23 .

[0038] The indoor heat exchanger 25 exchanges heat between the air sent by the indoor blower 25A and the heat medium, thereby providing conditioned air to the machine room 8. The indoor blower 25A is driven by a motor to blow the air in the machine room 8 (inside air) or outside air, or a mixed gas of the inside air and outside air to the indoor heat exchanger 25. The indoor blower 25A is preferably configured to be controllable in a variable speed. The HVAC (Heating, Ventilation, and Air Conditioning) unit U includes an indoor heat exchanger 25, an indoor blower 25A, and a duct (not shown) through which the air sent by the indoor blower 25A flows.

[0039] By switching the flow of the heating medium by at least one of the first to third switching valves 31, 32, and 33, the heating medium circuit 20 is configured to be able to set the low-pressure side circuit C1 and the high-pressure side circuit C2 in parallel ( Figure 1 ), and is configured to be able to set a series circuit CC ( Figure 2 ).

[0040] The high-pressure circuit C2 of the heat medium flowing out of the condenser 12 and returning to the condenser 12 is separated from the low-pressure circuit C1 flowing out of the evaporator 14 and returning to the evaporator 14. Hereinafter, the low-pressure circuit C1 and the high-pressure circuit C2 may be referred to as parallel circuits C1 and C2. The heating medium of the high-pressure side circuit C2 including the condenser 12 and the heating medium of the low-pressure side circuit C1 including the evaporator 14 are not mixed with each other.

[0041] In the parallel circuit C1, C2 Figure 1In the figure, the flow of the relatively low temperature heat medium (low temperature heat medium) circulating in the low pressure side circuit C1 is indicated by a solid line, and the flow of the relatively high temperature heat medium (high temperature heat medium) circulating in the high pressure side circuit C2 is indicated by a single dotted line. The path where neither the low temperature heat medium nor the high temperature heat medium is pressure-fed is indicated by a dotted line.

[0042] On the other hand, the series circuit CC is equivalent to a continuous circuit including the evaporator 14 and the condenser 12 arranged in series. When the series circuit CC is set, for example, Figure 2 As shown, the heat transfer medium flowing out of the condenser 12 flows into the evaporator 14 and then flows into the condenser 12 . In the series circuit CC Figure 2 In the figure, the flow of a relatively low temperature heat carrier is represented by a solid line, and the flow of a relatively high temperature heat carrier is represented by a dashed line. Figure 2 Unlike the case where parallel circuits C1 and C2 are provided, the flow of the heat medium from the evaporator 14 to the condenser 12 is indicated by a solid line, and the flow of the heat medium from the condenser 12 to the evaporator 14 is indicated by a dashed line. This means that if the heat medium flows into the evaporator 14, the temperature of the heat medium decreases due to heat dissipation to the refrigerant, and if the heat medium flows into the condenser 12, the temperature of the heat medium increases due to heat absorption from the refrigerant.

[0043] When the series circuit CC is set, the heating medium repeats the temperature rise based on the condenser 12 and the temperature drop based on the evaporator 14, and circulates in the condenser 12 and the evaporator 14. At this time, a continuous loop is formed in the heating medium circuit 20, so the heating medium can be pumped by only at least one of the first pump 21 and the second pump 22. That is, when the temperature control system 1 has only an operation mode using the series circuit CC, only one of the first pump 21 and the second pump 22 is required.

[0044] The rotation speed of the pumps 21 and 22 described later may be set for at least one of the pumps 21 and 22 to be operated. From the viewpoint of obtaining the waste heat from the pumps 21 and 22 to the maximum, it is preferable to operate the two pumps 21 and 22 and set the rotation speed N of one of the pumps 21 and 22 to the maximum even in the operation mode using the series circuit CC.

[0045] The first to third switching valves 31 to 33 are all electric valves that can be opened and closed by commands from the control device 5 , and are configured to be able to switch the flow path of the heating medium in accordance with each operation mode. In order to set a desired path in the heating medium circuit 20 to realize a desired operation mode, the first to third switching valves 31 to 33 can be replaced by electric valves having an appropriate structure and an appropriate number.

[0046] 〔Control device structure〕 like Figure 3 As shown, the control device 5 corresponds to a computer including a memory 501, a calculation unit 502, a storage unit 503, and an input / output unit 504. "Computer" also includes a programmable logic controller (PLC). The control device 5 operates according to a computer program read from the storage unit 503 and executed.

[0047] In each operation mode, the control device 5 controls the drive of the compressor 11 based on a computer program read from the storage unit 503 and executed, and can increase or decrease the cooling capacity or heating capacity by increasing or decreasing the circulation flow rate of the refrigerant. The control device 5 detects physical quantities related to the room temperature, such as the outside temperature, the blown-out temperature of air-conditioned air, or the temperature of the heat carrier or the temperature of the refrigerant, through sensors 61, 62, etc., and performs feedback control such as controlling the rotation speed of the compressor 11 to eliminate the deviation between the detected value and the target value, thereby being able to control the room temperature to the target temperature.

[0048] Furthermore, the control device 5 is configured to be able to set the rotation speed N of the pressure-feeding mechanism of the pumps 21 and 22 . In the present embodiment, the same rotation speed N is set for the pumps 21 and 22 , but the present invention is not limited thereto. Different rotation speeds N may be set for the pumps 21 and 22 , respectively.

[0049] The control device 5 generates, for example, a control command indicating the reference rotation speed of each of the pumps 21 and 22 determined for each operation mode. The reference rotation speed is determined, for example, as follows and stored in the storage unit 503 .

[0050] Cooling mode: 1st speed N1 Heat pump mode: 1st speed N1 Heater mode: 2nd speed N2 The second rotation speed N2 corresponds to, for example, 1.2 to 2 times the first rotation speed N1. The second rotation speed N2 may be a maximum rotation speed corresponding to the maximum axial force output from the motor to the pressure-feeding mechanism of the pump.

[0051] The rotation speed N of the pumps 21 and 22 is set in at least the heater mode HT among the plurality of operation modes. For example, when the temperature control system 1 is started in the heat pump mode HP, or when switching from the heat pump mode HP to the heater mode HT, the control device 5 generates a control instruction S corresponding to the heater mode HT to the pumps 21 and 22. HT . Then, the drive circuit portion 21D of the first pump 21 applies the control command S to the motor 21M. HT The first pump 21 is driven at the second rotation speed N2 by the corresponding driving current. Similarly, the driving circuit portion 22D provided in the second pump 22 applies the control command S to the motor 22M. HT The second pump 22 is driven at the second rotation speed N2 by the corresponding driving current. The rotation speed N of each of the pumps 21 and 22 can be controlled by increasing or decreasing the frequency or duty ratio of the drive current applied to the motors 21M and 22M, for example.

[0052] [Explanation of operation mode] First of all, Figure 1 The heat pump mode HP shown will be briefly described. Heat pump mode HP( Figure 1 ): The heat pump mode HP corresponds to a mode for heating the interior of the machine room 8 , and heat is heated by extracting heat from the outside air as a heat source into a high-temperature heat medium having a temperature higher than the outside temperature and transferring the heat to the machine room 8 .

[0053] In the heat pump mode HP, the temperature control system 1 operates using the parallel circuits C1 and C2. The low-temperature heat medium flowing out of the evaporator 14 flows into the outdoor heat exchanger 23 through the second switching valve 32 as shown by the solid arrow. The heat medium that absorbs heat from the outside air returns to the evaporator 14 through the first switching valve 31 and the evaporator flow control valve 14V. The refrigerant evaporates by absorbing heat from the heating medium flowing into the evaporator 14, and is sucked into the compressor 11. The refrigerant discharged from the compressor 11 condenses in the condenser 12 by dissipating heat to the heating medium, thereby raising the temperature of the heating medium.

[0054] As indicated by the dashed arrow, the high-temperature heating medium flowing out of the condenser 12 flows into the indoor heat exchanger 25 via the third switching valve 33. The heating medium heated in the machine room 8 returns to the condenser 12 via the first switching valve 31 and the condenser flow control valve 12V.

[0055] The heat pump mode HP utilizes the outside air as a part of the heat source, thereby ensuring the heating capacity while suppressing the increase in the power of the compressor 11, the pumps 21, 22, and the like.

[0056] Heater mode HT( Figure 2 ): Next, refer to Figure 2, the operation mode using the series circuit CC, namely the heater mode HT, is described. When the outside temperature is significantly lower than 0°C, for example, when the outside temperature drops below -20°C, the amount of heat that can be absorbed from the outside air to the heat medium through the above-mentioned heat pump mode HP is reduced, and the density of the refrigerant sucked into the compressor 11 is reduced, and the power of the compressor 11 becomes smaller. Even in this case, the heater mode HT can serve as a heat source for providing heat to the refrigerant passing through the compressor 11, and at the same time as a heat source for providing heat to the heating medium passing through the pumps 21 and 22 whose rotation speed N is set higher than that in other operation modes, for heating the temperature control object.

[0057] For example, similar to a resistance heating electric heater, in the heater mode HT, heat corresponding to the supplied power is supplied to the temperature-controlled object. Therefore, although it is called a "heater" mode, the name of the heater mode HT is not necessarily limited to this. In addition, the startup heater mode HT0 described later is a mode based on the premise of transition to the heater mode HT, and therefore uses the same name as the heater mode HT, but the name of the startup heater mode HT0 is not necessarily limited to this.

[0058] refer to Figure 2 , the flow of the heating medium in the heater mode HT is described. In order to prevent the heat transfer of the heating medium to the outside air, the heating medium is bypassed from the outdoor heat exchanger 23 through the outdoor bypass path 24. At this time, the operation of the outdoor blower 23A can be stopped. The rotation speed N of the pumps 21 and 22 is set to the second rotation speed N2, for example.

[0059] The heat medium that absorbs heat from the refrigerant in the condenser 12 flows into the indoor heat exchanger 25 via the third switching valve 33, and is used for heating in the machine room 8. Then, the heat medium that flows out of the indoor heat exchanger 25 flows into at least the evaporator 14 and the evaporator 14 in the evaporator bypass path 14A via the first switching valve 31 and the evaporator flow control valve 14V, and dissipates heat to the refrigerant. The heat carrier flowing out of the evaporator 14 flows into the outdoor bypass path 24 from the second switching valve 32, and after merging between the first switching valve 31 and the condenser flow regulating valve 12V, flows into at least the condenser 12 and the condenser 12 in the condenser bypass path 12A, thereby absorbing heat from the refrigerant.

[0060] Here, the pumps 21 and 22 operate at a predetermined efficiency η. In simple terms, most of the loss, which is the product of the shaft power P output from the motors 21M and 22M to the pumps 21 and 22 and (1-efficiency η), is transferred to the heat medium as heat energy. In the heater mode HT, the rotation speed N of the pumps 21 and 22 is increased to the second rotation speed N2 relative to the first rotation speed N1 in the heat pump mode HP, etc., so that the discharge flow rate of the heat medium of the pumps 21 and 22 increases compared to the flow rate in other operation modes, and the heat transferred from the pumps 21 and 22 to the heat medium increases. As a result, the heat dissipation from the heat medium to the refrigerant in the evaporator 14 increases, and the low pressure pL of the refrigerant circuit 10 rises.

[0061] Figure 4 Refrigeration cycle Y1 (dashed line) in heat pump mode HP and refrigeration cycle Y2 (solid line) in heater mode HT are shown in FIG. Refrigeration cycles Y1 and Y2 are both based on the condition of an outside temperature of -20°C. In the heat pump mode HP, the refrigerant needs to absorb heat from the heating medium flowing into the evaporator 14 by exchanging heat with the outside air at -20°C, so the low pressure pL decreases.

[0062] On the other hand, in the heater mode HT, the heat medium passing through the condenser 12 and the indoor heat exchanger 25 dissipates heat to the refrigerant through the evaporator 14. In addition, due to the increase in the rotation speed N of the pumps 21 and 22, the amount of heat input from the heat medium to the refrigerant increases, so that Figure 4 As shown, the low pressure pL increases compared to the heat pump mode HP. As a result, the density of the refrigerant sucked into the compressor 11 (hereinafter, compressor suction density ρ) increases, thereby increasing the power of the compressor 11 and the circulation flow rate of the refrigerant, thereby improving the heating capacity. Furthermore, due to the increase in the discharge flow rate of the heating medium caused by the increase in the rotation speed N of the pumps 21 and 22, the amount of heat absorbed from the refrigerant to the heating medium in the condenser 12 increases, and the heating capacity also improves.

[0063] In the heater mode HT, the heat medium avoids heat dissipation to the outside air and flows in the outdoor bypass path 24, and receives heat generated by the power of the pumps 21 and 22, and further receives heat generated by the power of the compressor 11 from the refrigerant and transmits it to the temperature control object. According to the heater mode HT, while increasing the speed N of the pumps 21 and 22 to increase the heat input to the refrigerant, the system operation without heat input and output with the outside air is utilized, so that the heating in the machine room 8 can be continued regardless of the outside air temperature.

[0064] [Main effects based on this embodiment] In the temperature control system 1 of a vehicle in which the heat source is easily insufficient, even under the condition that the heat absorption from the outside air is insufficient because the outside temperature is significantly lower than 0°C, the insufficient heat source can be compensated by increasing the power of the pumps 21 and 22 in the heater mode HT, thereby ensuring the heating function. Therefore, compared with the heater mode HP, the temperature in the engine room 8 can reach the target temperature earlier.

[0065] Furthermore, in the heater mode HT using the series circuit CC, since the condenser 12 and the evaporator 14 are connected in series, the temperature of the heating medium flowing out of the condenser 12 can be increased more quickly than when the heating medium flows in parallel into the condenser 12 and the evaporator 14. Furthermore, since the circulation amount of the heating medium in the indoor heat exchanger 25 is large, the amount of heat exchange between the heating medium and the air becomes large.

[0066] [First Modification] In heat pump mode HP( Figure 1 ), the rotation speed N of the second pump 22 corresponding to the high-pressure side circuit C2 can be set to a rotation speed higher than the rotation speed N of the first pump 21, for example, set to the second rotation speed N2 in the same manner as in the heater mode HT. Therefore, compared with the case where the rotation speed N of the second pump 22 is the same as the rotation speed N of the first pump 21 and the waste heat from the second pump 22 is small, the amount of heat absorbed from the refrigerant to the heating medium by the condenser 12 can be increased, thereby improving the heating capacity. The first pump 21 corresponding to the low-pressure circuit C1 does not need to increase the rotation speed N in order to ensure a temperature difference between the outside air and the heating medium of the low-pressure circuit C1 required for absorbing heat from the outside air.

[0067] [Second Modification] The rotation speed N of the pumps 21 and 22 in the heater mode HT can be set only when the temperature of the heating medium is lower than a predetermined temperature. For example, when the temperature of the heating medium flowing out of the evaporator 14 is lower than the threshold value T1, the heating capacity may not be sufficient. Therefore, the control device 5 determines, for example, that the temperature of the heating medium is detected by the heating medium temperature sensor 65 ( Figure 2 ) Whether the detected temperature is lower than the threshold value T1. As a result of the determination, when the detected temperature is lower than the threshold value T1, the control device 5 sets the rotation speed N of the pumps 21 and 22 to a rotation speed N higher than that of other operation modes, for example, to the second rotation speed N2.

[0068] [Third Modification] Furthermore, in the heater mode HT, the rotation speed N of the pumps 21 and 22 can be set to a rotation speed corresponding to the heat load. Here, the "air conditioning load" as a cooling load or a heating load is defined by the following formula (1). The air temperature in the formula is strictly speaking the air enthalpy. The air volume in the formula is strictly speaking the mass flow rate. Air conditioning load L = air volume Q × (target air temperature T T - Intake air temperature T I )…(1) The heating load increases as the outside temperature decreases.

[0069] The air volume Q is the volume flow rate of air sent to the indoor heat exchanger 25 by the indoor blower 25A and the running of the vehicle. The air volume Q can be obtained based on the setting level of the occupant or the setting level of the temperature control system 1, and the blowing mode (Face / Foot / Defogger, etc.). Target outlet air temperature T T The target temperature of the air blown out from the HVAC unit U into the machine room 8 is set according to the target temperature of the air in the machine room 8. T Detected by the temperature sensor 62 . Intake air temperature T I It refers to the temperature of the air introduced into the indoor heat exchanger 25 by the indoor blower 25A and the running of the vehicle. When the internal circulation is set, the intake air temperature T I This corresponds to the room temperature in the machine room 8 detected by a room temperature sensor (not shown), and corresponds to the outside temperature detected by the outside temperature sensor 61 when outside air introduction is provided. When the outside temperature is significantly lower than 0℃, T T With T I The difference ΔT is large, so the heating load is high.

[0070] In the heater mode HT, the controller 5 can assign a rotation speed N corresponding to the air conditioning load L to the pumps 21 and 22 as the air conditioning load L calculated by the formula (1) is relatively high, and assign a lower rotation speed N corresponding to the air conditioning load L to the pumps 21 and 22 as the air conditioning load L is relatively low. By increasing or decreasing the rotation speed N according to the air conditioning load L, the heating capacity can be variably controlled. According to the third modification, it is possible to operate in the power saving mode while suppressing power while ensuring sufficient heating capacity for the air-conditioning load L.

[0071] [Fourth Modification] In the heater mode HT, by controlling the rotation speed N of the pumps 21 and 22 , at least the low pressure pL of the refrigerant circuit 10 can be controlled. In the heater mode HT, the control device 5 controls the low pressure pL to be greater than or equal to 0.2 MPa and less than or equal to 1.2 MPa. Furthermore, in the heater mode HT, the control device 5 preferably controls the high-pressure pH to be 2.8 MPa or less.

[0072] [Low pressure-compressor dynamic characteristics in heater mode] Figure 5 It shows the relationship between the low pressure pL (horizontal axis) and the power of the compressor 11 (vertical axis) in the heater mode HT. This is the result calculated under the condition that the high pressure pH is constant and the speed of the compressor 11 is also constant. The solid line shows the case of R1234yf, and the single-point dash line shows the case of propane (R290). For any refrigerant, the low pressure-compressor power characteristic LPP presents a peak-shaped curve, and its peak is located at about 1MPa. The following applies to both refrigerants unless otherwise specified.

[0073] Figure 5 The value range of the low pressure pL shown is 0.1 MPa or more and 2.1 MPa or less. The low pressure pL starts from 0.1 MPa, rises to a peak value while the increase rate gradually decreases, and if it exceeds the peak value and turns to decrease, it decreases while the decrease rate gradually increases.

[0074] As the low pressure pL rises from 0.1 MPa to 1 MPa, the power of the compressor 11 increases, and thus the heating capacity based on the heat corresponding to the power of the compressor 11 also increases. However, if the low pressure pL exceeds the peak value and becomes too high, sufficient heating capacity cannot be obtained for the low outside temperature due to the decrease in power. The low pressure pL gradually decreases from the peak value, so even if it exceeds the peak value, the heating capacity up to 1.2 MPa is allowed.

[0075] This low pressure compressor dynamic characteristic LPP is consistent with the refrigeration cycle Y2 ( Figure 4 ) corresponds. If the low pressure pL rises, the compressor 11 power increases as the compressor suction density ρ increases, while the pressure difference Δp between the high pressure pH and the low pressure pL decreases. Therefore, as the enthalpy difference Δh( Figure 4 ) decreases, the power of the compressor 11 decreases. That is, during the period when the low pressure pL rises to 1 MPa, the increase in power caused by the increase in the compressor suction density ρ is greater than the decrease in power caused by the decrease in the enthalpy difference Δh.

[0076] According to the low pressure-compressor dynamic characteristic LPP, even if the low pressure pL rises in the heater mode HT, if the low pressure pL is too low or too high, the heating capacity will not increase, so the effect of increasing the heating capacity may not necessarily be obtained. Therefore, in order to ensure sufficient heating capacity at low external temperatures, the control device 5 maintains the low pressure pL at 0.2 MPa or more and 1.2 MPa or less in the heater mode HT. This control of the low pressure pL is based on the fact that, unlike the heat pump mode HP, the heater mode HT does not absorb heat from the outside air to the heating medium, and therefore the low pressure pL can be freely increased to a pressure corresponding to saturated steam or higher.

[0077] [High-pressure-compressor dynamic characteristics in heater mode] The relationship between the high-pressure pH and the compressor power in the heater mode HT is omitted. As the high-pressure pH increases, the compressor power gradually increases, so the higher the high-pressure pH, the higher the heating capacity. From the viewpoint of increasing the pressure difference Δp to sufficiently ensure the heating capacity, it is preferred to set the high-pressure pH as high as possible within the range of ensuring the pressure resistance of the equipment such as the housing of the compressor 11. Therefore, the control device 5 preferably limits the high-pressure pH to, for example, more than twice the low pressure pL and less than 2.8 MPa at least in the heater mode HT.

[0078] [Refrigerant pressure control in heater mode] In order to control the low pressure pL to the above value in the heater mode HT, the rotation speed N of the pumps 21 and 22 can be increased or decreased. If the rotation speed N of the pumps 21 and 22 is changed, the flow rate of the heating medium circulating in the path of the evaporator 14 including the heating medium circuit 20 changes, and the amount of heat transferred from the pumps 21 and 22 to the heating medium changes. As a result, the amount of heat dissipated from the heating medium to the refrigerant in the evaporator 14 changes, and the low pressure pL changes.

[0079] The control device 5 can perform feedback control to provide the rotation speed N (control command) as an operation amount to the pumps 21 and 22 while detecting the low pressure pL detected by the low pressure sensor 63 so as to eliminate the deviation between the detected value and the target pressure.

[0080] Furthermore, in order to control the high-pressure pH to the above-mentioned value in the heater mode HT, the rotation speed N of the pumps 21 and 22 can also be increased or decreased. If the rotation speed N of the pumps 21 and 22 is changed, the flow rate of the heating medium circulating in the path of the condenser 12 including the heating medium circuit 20 changes. Accordingly, the amount of heat absorbed from the refrigerant to the heating medium in the condenser 12 changes, and the high-pressure pH changes.

[0081] The control device 5 can detect the high pressure pH detected by the high pressure sensor 64 and perform feedback control to provide the rotation speed N (control command) as an operation amount to the pumps 21 and 22 so as to eliminate the deviation between the detected value and the target pressure.

[0082] According to the fourth variant, based on the low pressure-power characteristic LPP under the heater mode HT, the low pressure pL is controlled to be above 0.2 MPa and below 1.2 MPa, and at the same time, the rotation speed of the pumps 21 and 22 under the heater mode HT is increased within the range of above 0.2 MPa and below 1.2 MPa relative to the rotation speed in other operating modes, thereby reliably ensuring the heating capacity.

[0083] [Fifth Modification] The temperature control system 1 of the above embodiment may include Figure 6 The heater mode HT0 is shown during startup. In the heater mode HT0 at startup, the heat medium is made to flow into the outdoor heat exchanger 23 so that the heat medium absorbs heat from the outside air through the outdoor heat exchanger 23. Furthermore, in order to give priority to the heating of the refrigerant over the heating in the machine room 8, the heat medium is made to bypass the condenser bypass path 12A instead of flowing into the condenser 12, thereby preventing the refrigerant from radiating heat to the heat medium. Then, the heat medium flowing out of the indoor heat exchanger 25 is made to radiate heat to the refrigerant in the evaporator 14. Furthermore, in order to suppress the heat exchange between the air in the indoor heat exchanger 25 and the heat medium, it is preferred to stop the operation of the indoor air blower 25A.

[0084] In order to increase the amount of heat input to the refrigerant in the heater mode HT0 at startup, the rotation speed N of each of the first and second pumps 21 and 22 can be increased, for example, to the maximum rotation speed. In this way, in addition to the heat given to the refrigerant from the outside air via the heating medium, heat corresponding to the power of the first and second pumps 21 and 22 can be given from the heating medium to the refrigerant, and the heat dissipation from the heating medium to the refrigerant is promoted by increasing the circulation flow of the heating medium, thereby promoting the transition of the refrigerant circuit 10 to stable operation. Therefore, the time required from the start-up heater mode HT0 to the transition to the heater mode HT when the temperature control system 1 is started can be suppressed, so that heating in the machine room 8 can be started as soon as possible.

[0085] The heat exchange between the heating medium and the refrigerant and the heat exchange between the heating medium and the air are suppressed from the outlet of the outdoor heat exchanger 23 through the condenser bypass path 12A and the indoor heat exchanger 25 to the inlet of the evaporator 14. The heating medium, which absorbs heat from the outside air, passes through the condenser bypass path 12A and the indoor heat exchanger 25 and transfers the heat to the evaporator 14 where the refrigerant flows.

[0086] During the period when the vehicle is stopped in a state where the outside temperature is very low and below freezing, the temperatures of the heating medium and the refrigerant drop to the same level as the outside temperature. Therefore, by starting the temperature control system 1, the compressor 11 is started, and after the refrigeration cycle starts, the low pressure pL of the refrigerant circuit 10 drops by cooling the heating medium by the refrigerant, and the evaporation temperature of the refrigerant is lower than the outside temperature. However, according to the heater mode HT0 at startup, the heat absorbed from the outside air to the heating medium and the waste heat from the pumps 21 and 22 are continuously transferred to the refrigerant, and the low pressure of the refrigerant circuit 10 gradually rises, and the evaporation temperature also rises. Then, the low pressure pL rises to the specified value, and the refrigerant circuit 10 is stably operated, and the temperature control object can be heated by extracting heat from the power of the compressor 11 to the heating medium, so it can be transferred to the heater mode HT.

[0087] If the temperature of the heating medium exceeds the outside temperature, the heat absorption from the outside air becomes insufficient, so the control device 5 can transfer the temperature control system 1 to the heater mode HT when the heating medium approaches the outside temperature. For example, when the temperature of the heating medium exceeds a threshold value T3 lower than the outside temperature (for example, -20°C) by a predetermined temperature difference α, it can be transferred to the heater mode HT.

[0088] In addition to the above, the structures listed in the above embodiments may be selected or replaced, or may be appropriately changed to other structures.

[0089] The temperature control system 1 may include other temperature control devices such as a battery device in addition to or in place of the indoor heat exchanger 25 as a temperature control device. In this case, the heating medium circuit 20 includes a path for cooling or heating other temperature control devices with the heating medium.

[0090] [Note] Through the above disclosure, the structure described below is understood. [1] A vehicle temperature control system 1, comprising: The refrigerant circuit 10 includes a compressor 11, a high-pressure side heat exchanger 12, a pressure reducing unit 13, and a low-pressure side heat exchanger 14, and is configured so that the refrigerant can circulate according to a refrigeration cycle; and The heating medium circuit (20) is configured to allow a heating medium for exchanging heat with the refrigerant to circulate. The heat carrier circuit 20 comprises: The high-pressure side heat exchanger 12 enables the refrigerant to exchange heat with the heat carrier; The low-pressure side heat exchanger 14 enables the refrigerant to exchange heat with the heat carrier; The pumps 21 and 22 are configured to pressurize the heat medium; The outdoor heat exchanger 23 allows the external air to exchange heat with the heat carrier; The temperature control device 25 is equivalent to the temperature control object heated or cooled by the heat carrier, or is used for heating or cooling the temperature control object; and The outdoor bypass path 24 allows the heat medium to bypass the outdoor heat exchanger 23. The temperature control system 1 has a power heat source mode HT as an operation mode NP, The power heat source mode HT is a mode in which the heat medium flowing out of the high-pressure side heat exchanger 12 flows into the low-pressure side heat exchanger 14 via the temperature control device 25, and then flows into the high-pressure side heat exchanger 12 via the outdoor bypass path 24. The power of the compressor 11 and the power of the pumps 21 and 22 are used as heat sources. The device further comprises a control device 5 configured to be able to variably set the rotation speed N of the pumps 21 and 22. The control device 5 is configured as follows: At least the rotational speed N of the pumps 21 and 22 can be changed to the first rotational speed N1 and the second rotational speed N2, and in the power heat source mode HT, the second rotational speed N2 greater than the first rotational speed N1 set in the pumps 21 and 22 in the other operation mode NP can be set in the pumps 21 and 22.

[0091] [2] The vehicle temperature control system 1 described in item [1], wherein: The heat medium circuit 20 includes a first pump 21 and a second pump 22 as the pumps 21 and 22. The temperature control system 1 has a heat pump mode HP as another operation mode. The heat pump mode HP forms a low-pressure side loop C1 and a high-pressure side loop C2. The low-pressure side loop C1 is used to allow the heat carrier to circulate in the low-pressure side heat exchanger 14 and the outdoor heat exchanger 23 through the first pump 21, and the high-pressure side loop C2 is used to allow the heat carrier to circulate in the high-pressure side heat exchanger 12 and the temperature control device 25 through the second pump 22.

[0092] [3] The vehicle temperature control system described in [2], wherein: The control device 5 is configured as follows: In the heat pump mode HP, the rotation speed N which is larger than the first rotation speed N1 set in the first pump 21 can be set in the second pump 22 .

[0093] [4] The vehicle temperature control system according to any one of [1] to [3], wherein: The control device 5 is configured as follows: In the power heat source mode HT and when the temperature of the heating medium is lower than a predetermined temperature, the second rotation speed N2 can be set to the pumps 21 and 22 .

[0094] [5] The vehicle temperature control system according to any one of [1] to [4], wherein: The control device 5 is configured as follows: In the power heat source mode HT, the rotation speed N corresponding to the heat load can be set to the pumps 21 and 22 .

[0095] [6] The vehicle temperature control system according to any one of [1] to [5], wherein: The control device 5 is configured as follows: In the power heat source mode HT, by controlling the rotation speed N based on control commands to the pumps 21 , 22 , at least the low pressure pL of the refrigerant circuit 10 and the high pressure pH is controlled.

[0096] [7] A vehicle temperature control method, which is a vehicle temperature control method using a vehicle temperature control system 1, wherein: The temperature control system 1 has: The refrigerant circuit 10 includes a compressor 11, a high-pressure side heat exchanger 12, a pressure reducing unit 13, and a low-pressure side heat exchanger 14, and is configured so that the refrigerant can circulate according to a refrigeration cycle; and The heating medium circuit (20) is configured to allow a heating medium for exchanging heat with the refrigerant to circulate. The heat carrier circuit 20 comprises: The high-pressure side heat exchanger 12 enables the refrigerant to exchange heat with the heat carrier; The low-pressure side heat exchanger 14 enables the refrigerant to exchange heat with the heat carrier; The pumps 21 and 22 are configured to pressurize the heat medium; The outdoor heat exchanger 23 allows the external air to exchange heat with the heat carrier; The temperature control device 25 is equivalent to the temperature control object heated or cooled by the heat carrier, or is used for heating or cooling the temperature control object; and The outdoor bypass path 24 allows the heat medium to bypass the outdoor heat exchanger 23. In the temperature control method, In the power heat source mode HT, a second rotation speed N2 which is larger than the first rotation speed N1 set to the pumps 21 and 22 in the other operation mode HP is set to the pumps 21 and 22. The power heat source mode HT is a mode in which the heat carrier flowing out of the high-pressure side heat exchanger 12 flows into the low-pressure side heat exchanger 14 via the temperature control device 25, and then flows into the high-pressure side heat exchanger 12 through the outdoor bypass path 24. The mode utilizes the power of the compressor 11 and the power of the pumps 21 and 22 as heat sources. Explanation of symbols

[0097] 1- Temperature control system, 5- Control device, 8- Machine room, 10- Refrigerant circuit, 11- Compressor, 12- Condenser (High-pressure side heat exchanger), 12A- Condenser bypass path (High-pressure side bypass path), 12V- Condenser flow control valve (High-pressure side flow control valve), 13- Expansion valve (Decompression section), 14- Evaporator (Low-pressure side heat exchanger), 14A- Evaporator bypass path (Low-pressure side bypass path), 14V- Evaporator flow control valve (Low-pressure side flow control valve), 15- Liquid storage tank, 16- Communication path, 17- Opening and closing valve, 20- Heat medium circuit, 21- 1st pump (pump), 21D- Drive circuit section, 21M- Motor, 22- 2nd pump (pump), 22D- Drive circuit section, 22M- Motor, 23- Outdoor heat exchanger, 23A- Outdoor blower, 24- Outdoor bypass Passage path, 25-indoor heat exchanger (temperature control equipment), 25A-indoor fan, 31-1st switching valve, 32-2nd switching valve, 33-3rd switching valve, 61-outside temperature sensor, 62-temperature sensor, 63-low pressure pressure sensor, 64-high pressure pressure sensor, 65-heat carrier temperature sensor, 401, 402-piping, 501-memory, 502-calculation unit, 503-storage unit, 504-input and output unit, C1-low pressure side circuit, C2-high pressure side circuit, CC-series circuit, HP-heat pump mode, HT-heater mode (power heat source mode), HT0-start-up heater mode, LPP-compressor dynamic characteristics, U-HVAC unit, Y1, Y2-refrigeration cycle, pH-high pressure, pL-low pressure, Δh-enthalpy difference, Δp-pressure difference.

Claims

1. A temperature control system for a vehicle, comprising: A refrigerant circuit includes a compressor, a high-pressure side heat exchanger, a pressure reducing unit, and a low-pressure side heat exchanger, and is configured so that the refrigerant can circulate according to a refrigeration cycle; and The heat medium circuit is configured to allow a heat medium for exchanging heat with the refrigerant to circulate. The heat carrier circuit comprises: The high-pressure side heat exchanger enables the refrigerant to exchange heat with the heat carrier; The low-pressure side heat exchanger enables the refrigerant to exchange heat with the heat carrier; A pump configured to pressurize the heat medium; An outdoor heat exchanger is used to exchange heat between the external air and the heat carrier; The temperature control device is equivalent to the temperature control object heated or cooled by the heat carrier, or is used for heating or cooling the temperature control object; and The outdoor bypass path allows the heat medium to bypass the outdoor heat exchanger. The temperature control system has a power heat source mode as an operating mode, The power heat source mode is a mode in which the heat medium flowing out of the high-pressure side heat exchanger flows into the low-pressure side heat exchanger via the temperature control device and then flows into the high-pressure side heat exchanger via the outdoor bypass path. The power of the compressor and the power of the pump are used as heat sources. and comprising a control device configured to set the rotation speed of the pump to be variable, The control device is configured as follows: The rotation speed of the pump can be changed to at least a first rotation speed and a second rotation speed, and in the power heat source mode, the second rotation speed higher than the first rotation speed set to the pump in the other operation modes can be set to the pump.

2. The vehicle temperature control system according to claim 1, wherein: The heat medium circuit includes a first pump and a second pump as the pumps. The temperature control system has a heat pump mode as another operation mode. The heat pump mode forms a low-pressure side circuit and a high-pressure side circuit. The low-pressure side circuit is used to circulate the heat carrier through the low-pressure side heat exchanger and the outdoor heat exchanger through the first pump, and the high-pressure side circuit is used to circulate the heat carrier through the high-pressure side heat exchanger and the temperature control device through the second pump.

3. The vehicle temperature control system according to claim 2, wherein: The control device is configured as follows: In the heat pump mode, the rotation speed that is higher than the first rotation speed set for the first pump can be set for the second pump.

4. The vehicle temperature control system according to any one of claims 1 to 3, wherein: The control device is configured as follows: In the power heat source mode and when the temperature of the heating medium is lower than a predetermined temperature, the second rotation speed can be set for the pump.

5. The vehicle temperature control system according to any one of claims 1 to 3, wherein: The control device is configured as follows: In the power heat source mode, the rotation speed corresponding to the heat load can be set to the pump.

6. The vehicle temperature control system according to any one of claims 1 to 3, wherein: The control device is configured as follows: In the power heat source mode, at least the low pressure of the refrigerant circuit is controlled by controlling the rotation speed based on a control command to the pump.

7. A vehicle temperature control method, which is a temperature control method using a vehicle temperature control system, wherein: The temperature control system has: A refrigerant circuit includes a compressor, a high-pressure side heat exchanger, a pressure reducing unit, and a low-pressure side heat exchanger, and is configured so that the refrigerant can circulate according to a refrigeration cycle; and The heat medium circuit is configured to allow a heat medium for exchanging heat with the refrigerant to circulate. The heat carrier circuit comprises: The high-pressure side heat exchanger enables the refrigerant to exchange heat with the heat carrier; The low-pressure side heat exchanger enables the refrigerant to exchange heat with the heat carrier; A pump configured to pressurize the heat medium; An outdoor heat exchanger is used to exchange heat between the external air and the heat carrier; The temperature control device is equivalent to the temperature control object heated or cooled by the heat carrier, or is used for heating or cooling the temperature control object; and The outdoor bypass path allows the heat medium to bypass the outdoor heat exchanger. In the temperature control method, In the power heat source mode, a second rotation speed is set to the pump, which is greater than the first rotation speed set to the pump in other operation modes, The power heat source mode is a mode in which the heat carrier flowing out of the high-pressure side heat exchanger flows into the low-pressure side heat exchanger via the temperature control device, and then flows into the high-pressure side heat exchanger through the outdoor bypass path. The power heat source mode utilizes the power of the compressor and the power of the pump as heat sources.

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