Temperature control system and temperature control method for vehicle

Abstract

The invention provides a temperature control system and method for a vehicle, which can ensure heating capability even if the outside air temperature is low, and can perform heating of a heat load based on more appropriate mode switching. A temperature control system for a vehicle is provided with a refrigerant circuit and a heat medium circuit, and is provided with: a heat pump mode in which a low-pressure-side circuit in which a heat medium circulates and a high-pressure-side circuit in which the heat medium circulates are formed; in the compressor heat source mode, the heat carrier flowing out of the high-pressure side heat exchanger flows into the low-pressure side heat exchanger through temperature control equipment and then flows into the high-pressure side heat exchanger through an outdoor heat exchanger bypass path; and a mode selection unit. The mode selection unit is configured so as to select the heat pump mode when the detected outside air temperature is high and select the compressor heat source mode when the outside air temperature is low with respect to a switched outside air temperature relating to an intersection of the outside air temperature-heating capacity characteristics of each of the heat pump mode and the compressor 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 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 response to such requirements, in addition to heat pump systems, multiple systems have been used, 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 capable of integrating the thermal management of air conditioning and equipment, a system has been proposed, which comprises: a primary circuit in which a 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 provided with an evaporator of a refrigerant circuit and a heating medium external air heat exchanger; and a second heating medium circuit, which is provided 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 external air temperature by switching the flow paths by a first switching mechanism and a second switching mechanism.

[0005] In the non-connected mode, the heat pump operates to extract the heat of 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.

[0006] In the above-mentioned patent document 1, based on the physical quantity (ρ2) related to the heating medium temperature in the second heating medium circuit in the connected mode, when the following formula is satisfied, it is estimated that the amount of heat that can be input to the heating medium of the second heating medium circuit in the connected mode is greater than the amount of heat that can be input to the heating medium in the non-connected mode, and therefore the non-connected mode is switched to the connected mode. ρ2>A1×ρ1 Here, ρ1 is the density of the refrigerant sucked into the compressor in the non-connected mode, and ρ2 is the density of the refrigerant sucked into the compressor 11 in the non-connected mode. A1 is the coefficient of performance (COP: Coefficient of Performance) of the refrigeration cycle in the non-connected mode. Previous technical literature Patent Literature

[0007] Patent Document 1: Japanese Patent No. 6083304 Summary of the invention Technical issues to be solved by the invention

[0008] In Patent Document 1, as a switching condition from the non-connected mode equivalent to the heat pump operation to the connected mode, an index based on the compressor suction density in the non-connected mode and the connected mode and the COP corresponding to the outside air temperature is used. This mode switching condition compares the heat input to the heating medium in the non-connected mode with the heat input to the heating medium in the connected mode, and selects the one with a larger heat input. That is, although Patent Document 1 aims to ensure a more sufficient heating capacity, the power consumed for heating may increase.

[0009] Furthermore, 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 intermediate temperature of the temperatures of the respective heating mediums before mixing, and then 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. Furthermore, since the flow rate of the heating medium flowing into the indoor heat exchanger is reduced, there is room for improvement in the heating capacity.

[0010] 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 the outside air temperature is low and it is difficult to ensure a heat source, and can heat the temperature control object by more appropriate mode switching. Means for solving technical problems

[0011] 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 first pump and a second pump, both of which are 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 heat exchanger bypass path, which allows the heat carrier to bypass the outdoor heat exchanger. The temperature control system has the following modes as operating modes: a heat pump mode, forming a low-pressure side circuit in which the heat medium circulates through the first pump in the low-pressure side heat exchanger and the outdoor heat exchanger, and a high-pressure side circuit in which the heat medium circulates through the second pump in the high-pressure side heat exchanger and the temperature control device; a compressor 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 heat exchanger bypass path. The temperature control system also has: a mode selection unit, configured to be able to select the heat pump mode or the compressor heat source mode; and an external air temperature sensor, which detects the external air temperature. The mode selection unit is configured to select the heat pump mode when the outside air temperature detected by the outside air temperature sensor is high, and to select the compressor heat source mode when the outside air temperature is low, relative to an intersection outside air temperature set to correspond to the intersection of the outside air temperature-heating capacity characteristics of the heat pump mode and the compressor heat source mode, or a switching outside air temperature set to a temperature lower than the intersection outside air temperature.

[0012] Furthermore, the present invention can also be extended to a temperature control method for a vehicle. Effects of the Invention

[0013] According to the present invention, the mode selection unit uses the switching outside air temperature set based on the relevant data of the outside air temperature-heating capacity characteristics of the heat pump mode and the compressor heat source mode as a threshold to determine the mode selection. As a result, the heat pump mode or the compressor heat source mode can be appropriately selected based on the heating capacity dependent on the outside air temperature. For example, even if the compressor heat source mode is more suitable than the heat pump mode in terms of the amount of heat input into the heat medium for heat exchange with the high-pressure side heat exchanger, the heat pump mode that can operate in the power saving mode by absorbing heat from the outside air can be selected based on the characteristics of the outside air temperature and the heating capacity. In this way, when the heating capacity obtained by the heat pump mode is sufficient for the required heating capacity, the compressor heat source mode that obtains the required heat by inputting electricity into the compressor will not be selected, so economical operation can be performed.

[0014] In the compressor 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.

[0015] Furthermore, in the compressor heat source mode, the heat carrier passing through the high-pressure side heat exchanger and the indoor heat exchanger dissipates heat to the refrigerant through the low-pressure side heat exchanger. Therefore, compared with the heat pump mode, the low pressure of the refrigerant circuit increases, and the density of the refrigerant sucked into the compressor increases accordingly, thereby increasing the circulation flow of the refrigerant. Since the heating capacity is improved by the increase in the refrigerant circulation flow, the heating capacity can be improved, so that the temperature of the temperature-controlled object can reach the target temperature earlier.

[0016] According to the heat exchange system, by providing at least the compressor heat source mode, even when it is difficult to secure a heat source due to low outside air temperature, it is possible to secure heating capacity while supplying power required for securing a heat source to the compressor and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] 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 It is shown Figure 1 A diagram showing the system operating in heater mode. Figure 3 : is a block diagram showing the hardware configuration of a control device including a mode selection unit. Figure 4 (a) and Figure 4 (b) is a graph showing the outside air temperature-heating capacity characteristics of each of the heat pump mode and the heater mode. Figure 5 This is a flowchart showing an example of mode determination. Figure 6 This is a diagram for explaining mode selection according to the first modified example of the present invention. Figure 7 1 is a circuit diagram showing a vehicle temperature control system according to a second modified example of the present invention (start-up heater mode). DETAILED DESCRIPTION

[0018] Hereinafter, embodiments of the present invention will be described with reference to the drawings. [Implementation Method] Figure 1The 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 the 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 installed in the vehicle. The act of adjusting to an appropriate temperature or humidity, or managing the vehicle-mounted devices to an appropriate temperature is generally 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.

[0019] 〔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. Furthermore, the temperature control system 1 includes sensors such as an outside air temperature sensor 51 for detecting the outside air temperature and a room temperature sensor 52 for detecting the temperature (room temperature) in the machine room 8 .

[0020] The temperature control system 1 has a plurality of operation modes selected by the occupant or the control device 5. Regarding the heat pump mode HP ( Figure 1 ) and heater mode HT( Figure 2 ), which will be described later. The temperature control system 1 includes a mode selection unit 50 configured to be able to select a heat pump mode HP and a heater mode HT. The mode selection unit 50 may be included in the control device 5 .

[0021] 〔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.

[0022] 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. In the use of carbon dioxide (CO 2 ) is used as the refrigerant, a transition critical refrigeration cycle in which the refrigerant pressure on the high-pressure side exceeds the critical pressure of the refrigerant is constituted. 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 constituting a transition critical refrigeration cycle such as the carbon dioxide refrigerant can also be adopted in the refrigerant circuit 10.

[0023] 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. 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, an electronic expansion valve whose opening can be controlled based on a command from the control device 5 is preferably used. However, it is also acceptable to use a temperature expansion valve or a capillary tube instead of the expansion valve 13.

[0024] 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. A liquid receiver (gas-liquid separator) (not shown) may be provided between the evaporator 14 and the compressor 11 .

[0025] A relatively high refrigerant pressure (high pressure) is applied to the condenser 12, and a relatively low refrigerant pressure (low pressure) is applied to the evaporator 14. The refrigerant circulates in the refrigerant circuit 10 based on the pressure difference between the high pressure and the low pressure. exist Figure 1In FIG, 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 The following is also the same.

[0026] 〔Structure of the heat carrier circuit〕 The heating medium circuit 20 is configured to circulate a heating medium capable of exchanging heat with the refrigerant through the condenser 12 and the evaporator 14. The heating 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.

[0027] 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 heat exchanger 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.

[0028] 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 .

[0029] The heating medium circuit 20 preferably includes: a condenser bypass path 12A for allowing the heating medium to bypass the condenser 12; and an evaporator bypass path 14A for allowing the heating medium to bypass the evaporator 14. In this case, the heating medium circuit 20 preferably includes: a condenser flow rate regulating valve 12V configured to be able to adjust the flow rate ratio of the heating medium between the condenser 12 and the condenser bypass path 12A; and an evaporator flow rate regulating valve 14V configured to be able to adjust the flow rate ratio of the heating medium between the evaporator 14 and the evaporator bypass path 14A.

[0030] The first pump 21 pumps the heating medium flowing out of the evaporator 14 and discharges it, thereby pumping the heating medium. The second pump 22 pumps the heating medium flowing out of the condenser 12 and discharges it, thereby pumping the heating medium.

[0031] 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.

[0032] The outdoor heat exchanger bypass path 24 allows the heating medium to bypass the outdoor heat exchanger 23 .

[0033] The indoor heat exchanger 25 exchanges heat between the air sent by the indoor blower 25A and the heating medium, thereby supplying conditioned air into the machine room 8. The indoor blower 25A blows the air in the machine room 8 (inside air) or outside air toward the indoor heat exchanger 25. 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.

[0034] 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 ).

[0035] 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.

[0036] In the parallel circuit C1, C2 Figure 1 In the figure, the flow of the relatively low temperature heat carrier (low temperature heat carrier) circulating in the low pressure side circuit C1 is indicated by a solid line, and the flow of the relatively high temperature heat carrier (high temperature heat carrier) circulating in the high pressure side circuit C2 is indicated by a single dotted line. At this time, from position A to position B on the heat carrier circuit 20, only the low temperature heat carrier flows, and from position C to position D, only the high temperature heat carrier flows. The path where neither the low temperature heat carrier nor the high temperature heat carrier is pressure-fed is indicated by a dotted line.

[0037] 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 setting the series circuit CC, 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.

[0038] When the series circuit CC is set, the heat medium circulates in the condenser 12 and the evaporator 14 while repeating the temperature rise of the condenser 12 and the temperature drop of the evaporator 14. At this time, a continuous loop is formed in the heat medium circuit 20, so the heat medium can be pumped by only at least one of the first pump 21 and the second pump 22. However, even in the operation mode using the series circuit CC, by operating the two pumps 21 and 22 , a sufficient circulation flow rate of the heating medium in the heating medium circuit 20 can be obtained.

[0039] The first to third switching valves 31 to 33 are all electric valves that can be controlled to open and close based on a command from the control device 5 , and are configured to be able to switch the flow path of the heating medium. In order to set a path required for realizing a desired operation mode in the heating medium circuit 20 , the first to third switching valves 31 to 33 can be replaced with electric valves having an appropriate structure and an appropriate number.

[0040] 〔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. The "computer" also includes a programmable logic controller (PLC: programmable logic controller).

[0041] The control device 5 performs rotation speed control of the compressor 11 according to the heat load, etc., and increases or decreases the circulation flow rate of the refrigerant, thereby being able to increase or decrease the cooling capacity and the heating capacity respectively. In addition, the control device 5 detects physical quantities related to the room temperature, such as the room temperature, external air temperature, heating medium temperature, refrigerant temperature or pressure, etc. through sensors, and performs feedback control on the rotation speed of the compressor 11 to eliminate the deviation between the detected value and the target value, thereby adjusting the room temperature to the target temperature.

[0042] The storage unit 503 stores a computer program configured to execute the mode selection unit 50 .

[0043] The mode selection unit 50 executes the computer program based on the outdoor air temperature-heating capacity characteristics OH1 and OH2 ( Figure 4 (a)) to select either the heat pump mode HP or the heater mode HT. The mode selection unit 50 may be included in a computer different from the control device 5 .

[0044] [Explanation of heat pump mode] Next, refer to Figure 1 , the function of the temperature control system 1 in the heat pump mode HP is described. The heat pump mode HP corresponds to a mode for heating the interior of the machine room 8 , and heat is extracted from the outside air as a heat source to a high-temperature heating medium having a higher temperature than the outside air and transmitted to the machine room 8 , thereby heating the interior of the machine room 8 . In the heating medium circuit 20 , a circuit corresponding to the heat pump mode HP is set based on control commands to the first to third switching valves 31 to 33 , the condenser flow rate regulating valve 12V, and the evaporator flow rate regulating valve 14V.

[0045] In the heat pump mode HP, the temperature control system 1 operates using the parallel circuits C1 and C2. In the heat pump mode HP, a high-temperature heat medium is supplied to the indoor heat exchanger 25, and a low-temperature heat medium is supplied to the outdoor heat exchanger 23. That is, the low-temperature heating medium flowing out of the evaporator 14 flows into the outdoor heat exchanger 23 via the second switching valve 32 as indicated by the solid arrow. The heating medium having absorbed heat from the outside air returns to the evaporator 14 via the first switching valve 31 and the evaporator flow rate regulating 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.

[0046] 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.

[0047] 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.

[0048] exist Figure 1In 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 .

[0049] 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.

[0050] [Description of heater mode] Next, refer to Figure 2 , the operation mode using the series circuit CC, namely the heater mode HT, is explained. When the outside air temperature is significantly lower than 0°C, for example, when the outside air 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 such a case, the heater mode HT can be used to perform heating operation using the compressor 11 as a heat source. The heater mode HT uses the power of the compressor 11 to heat the temperature control object.

[0051] In the heater mode HT, heat corresponding to the supplied power is supplied to the temperature-controlled object, similarly to a resistance heating electric heater, for example. Therefore, although it is called a "heater" mode, the name of the heater mode HT is not necessarily limited to this. In addition, since the startup heater mode HT0 described later is a mode presupposing a transition to the heater mode HT, the same name as the heater mode HT is used, but the name of the startup heater mode HT0 is not necessarily limited to this.

[0052] The specific flow of the heating medium in the heater mode HT will be described. In order to prevent the heating medium from radiating heat to the outside air, the heating medium is bypassed from the outdoor heat exchanger 23 through the outdoor heat exchanger bypass path 24. At this time, the operation of the outdoor blower 23A may be stopped. The control device 5 sets a path corresponding to the heater mode HT in the heating medium circuit 20 by sending instructions to the first switching valve 31, the second switching valve 32, the evaporator flow regulating valve 14V, the condenser flow regulating valve 12V, the outdoor fan 23A and the indoor fan 25A.

[0053] 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 to provide 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 regulating valve 14V to dissipate heat to the refrigerant. The heat carrier flowing out of the evaporator 14 flows into the outdoor heat exchanger bypass path 24 from the second switching valve 32, and after merging with the flow from the first switching valve 31 toward the condenser 12 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.

[0054] In the heater mode HT, the heat medium receives heat generated by the power of the compressor 11 from the refrigerant and transmits it to the temperature control object while flowing in the outdoor heat exchanger bypass path 24 to avoid heat dissipation to the outside air. According to the heater mode HT, since the system is operated without heat input and output with the outside air, the heating in the machine room 8 can be continued regardless of the outside air temperature.

[0055] [Mode selection instructions] Mode selection between the heat pump mode HP and the heater mode HT by the mode selection unit 50 will be described. Figure 4 The horizontal axis of (a) is the outside air temperature T, and the vertical axis is the heating capacity CP. Figure 4 In (a), the outside air temperature-heating capacity characteristic OH1 in the heat pump mode HP is indicated by a solid line, and the outside air temperature-heating capacity characteristic OH2 in the heater mode HT is indicated by a single-dot chain line. Figure 4 (a) shows correlation data DT between the characteristic OH1 and the characteristic OH2.

[0056] Here, the "heating capacity" corresponds to the heating capacity when the rotation speed of the compressor 11 is the maximum (hereinafter referred to as the maximum heating capacity). At this time, the rotation speeds of the pumps 21 and 22 are also the maximum. At the maximum heating capacity of the heat pump mode HP, the entire amount of the heating medium flowing from the first switching valve 31 toward the evaporator 14 flows into the evaporator 14, and the entire amount of the heating medium flowing from the first switching valve 31 toward the condenser 12 flows into the condenser 12. In the maximum heating capacity of the heater mode HT, the entire amount of the heating medium flowing from the first switching valve 31 toward the evaporator 14 flows into the evaporator 14 , and the entire amount of the heating medium flowing from the first switching valve 31 toward the condenser 12 flows into the condenser 12 .

[0057] According to the characteristic OH1 , in the heat pump mode HP, the heating capacity CP gradually decreases as the outside air temperature T decreases. Also, according to the characteristic OH2 , in the heater mode HT, the heating capacity CP is constant regardless of the outside air temperature T. Based on the characteristics OH1 and OH2, the line representing the characteristics OH1 intersects with the line representing the characteristics OH2. The outside air temperature corresponding to the intersection point X of these lines is referred to as the intersection outside air temperature T.X At this intersection point, the outside air temperature T X The switch outside air temperature T is set S .

[0058] The mode selection unit 50 switches the mode when the outside air temperature T detected by the outside air temperature sensor 51 is higher than the switching outside air temperature T S In the case of selecting the heat pump mode HP, when the outside air temperature T detected by the outside air temperature sensor 51 is lower than the switching outside air temperature T S Select heater mode HT in this case. When the outside air temperature T is detected to be higher than the switching outside air temperature T S When , the heating capacity CP of the region R2 in the characteristic OH1 of the heat pump mode HP corresponding to the detected outside air temperature T is higher than the heating capacity CP of the heater mode HT. On the other hand, when the outside air temperature T is detected to be lower than the switching outside air temperature T S When , the heating capacity CP of the heater mode HT is higher than the heating capacity CP of the region R1 of the characteristic OH1 of the heat pump mode HP corresponding to the outside air temperature T. The control device 5 can switch the outside air temperature T based on S To determine the outside air temperature T as the threshold, either the heat pump mode HP or the heater mode HT is set as the operation mode of the temperature control system 1 .

[0059] Next, refer to Figure 4 (b) of the present invention will now be described an example of selecting a mode according to the air conditioning load L of the temperature control system 1. Figure 5 As shown, when the heat pump mode HP is selected by the above-mentioned determination of the outside air temperature T (No in step S01), the mode selection unit 50 does not select a mode based on the following determination, but determines the selected mode as the heat pump mode HP (step S02). On the other hand, it is preferred that when the heater mode HT is selected by the above-mentioned judgment (first judgment) of the outside air temperature T ("Yes" in step S01), that is, when the heating capacity CP of area R1 of the characteristic OH1 of the heat pump mode HP corresponding to the detected outside air temperature T is worse than the heating capacity CP of the heater mode HT, the operating mode is determined according to the air conditioning load L through the second judgment described below (steps S03 to S05).

[0060] exist Figure 4 In (b), L is shown as an example of the heating load, that is, the air conditioning load L of the temperature control system 1. 1 , L 2 .L 1 <L2 . Air conditioning load L 1 , L 2 All are heating loads, and the heating load decreases as the outside air temperature rises. Here, "air conditioning 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)

[0061] 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 Calculated by the room temperature sensor 52 and the like. 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 The room temperature detected by the room temperature sensor 52 is equivalent to the room temperature detected by the room temperature sensor 52. When no external air is introduced, the intake air temperature T I This corresponds to the outside air temperature detected by the outside air temperature sensor 51 . When the outside air temperature is significantly lower than 0°C, T T With T I The difference ΔT is large, so the air conditioning load is high.

[0062] The mode selection unit 50 preferably calculates the air conditioning load L according to the above formula, and sets the switching outside air temperature T according to the air conditioning load L. SL For example, if the air conditioning load is L 1 , then the external air temperature T SL Set to the same as the air conditioning load L 1 The temperature T corresponding to the intersection X1 of the outdoor air temperature-heating capacity characteristic OH1 of the heat pump mode HP 1 And, if the air conditioning load is L 2 , then the external air temperature T SL Set to the same as the air conditioning load L 1The temperature T corresponding to the intersection X2 of the outside air temperature-heating capacity characteristic OH1 of the heat pump mode HP 2 . When the outside air temperature T is higher than the switching outside air temperature T set according to the air conditioning load L SL In the case of (No in step S03), the mode selection unit 50 selects the heat pump mode HP (step S04), and when the outside air temperature T is lower than the switching outside air temperature T SL (YES in step S03), the mode selection unit 50 selects the heater mode HT (step S05).

[0063] For example, when the outside air temperature is T 1 And the air conditioning load is L 1 In the case of T SL =T ("No" in step S03), so the heat pump mode HP is selected (step S04). On the other hand, when the outside air temperature T is also T 1 And the air conditioning load is greater than L 1 L 2 In the case of T SL >T (YES in step S03 ), so the heater mode HT is selected (step S05 ).

[0064] When the outside air temperature is T 2 And the air conditioning load is L 1 In the case of T SL <T ("No" in step S03), so the heat pump mode HP is selected (step S04). And, when the outside air temperature T is also T 2 And the air conditioning load is greater than L 1 L 2 In the case of T SL =T (No in step S03), the heat pump mode HP is selected (step S04). However, even if the outside air temperature T does not change to T 2 , if the air conditioning load is higher than L 2 , then T SL >T ("Yes" in step S03) is established, so the heater mode HT is selected (step S05)

[0065] The control device 5 can switch the outside air temperature T based on SL To determine the outside air temperature T as the threshold, either the heat pump mode HP or the heater mode HT is set as the operation mode of the temperature control system 1 .

[0066] [Main effects based on this embodiment]

[0067] The switching outside air temperature T can be set by the mode selection unit 50 based on the correlation data DT of the outside air temperature-heating capacity characteristics OH1 and OH2 of the heat pump mode HP and the heater mode HT, respectively. S The mode selection is determined using the threshold value. In this way, based on the heating capacity CP depending on the outside air temperature T, the heat pump mode HP or the heater mode HT can be appropriately selected. When the air conditioning load L is high, such as when the outside air temperature T is significantly lower than 0° C., the heating target can be heated without causing a capacity shortage regardless of the influence of the outside air temperature T by selecting the heater mode HT in which the compressor 11 is operated as a heat source. Furthermore, even if the heater mode HT is more suitable than the heat pump mode HP in terms of the amount of heat input into the heat medium for heat exchange with the condenser 12, the heat pump mode HP that can be operated in the power saving mode by absorbing heat from the outside air can be selected based on the characteristics OH1 and OH2 between the outside air temperature T and the heating capacity CP. In this way, when the heating capacity obtained by the heat pump mode HP is sufficient for the required heating capacity, the heater mode HT that obtains the required amount of heat by inputting power to the compressor 11 is not selected, so that economical operation can be performed.

[0068] Furthermore, in the region R1 where the heating capacity CP of the heater mode HT is lower than the heating capacity CP of the heat pump mode HP, the switching outside air temperature T SL , the switching outside air temperature T SL Set to the same air conditioning load L(L 1 , L 2 ) and the temperature corresponding to the intersection (X1, X2) of the characteristic OH1 of the heat pump mode HP, thereby selecting an operation mode that satisfies the air conditioning load L in the heat pump mode HP and the heater mode HT. By appropriately selecting a mode based on the air conditioning load L, more economical operation can be achieved.

[0069] In addition to the above, 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.

[0070] Furthermore, 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, so compared with the heat pump mode HP, the low pressure of the refrigerant circuit 10 increases, and the density of the refrigerant sucked into the compressor 11 increases accordingly, thereby increasing the circulation flow rate of the refrigerant. Since the heat exchange capacity is improved by the increase in the refrigerant circulation flow rate, the heating capacity can be improved, so that the temperature in the machine room 8 can reach the target temperature earlier.

[0071] According to the temperature control system 1, by providing at least the heater mode HT, even when it is difficult to secure a heat source due to low outside air temperature, it is possible to secure heating capacity while supplying power required for securing a heat source to the compressor 11 and the like.

[0072] [First Modification] like Figure 6 As shown, switch the outside air temperature T S It can also be set to the external air temperature T X In this case, if the mode selection is performed based only on the first determination (step S01) described above, when the outside temperature T is higher than the switching outside temperature T S When the heating capacity CP is lower than that of the heater mode HT, the heat pump mode HP may be selected. However, the heating capacity CP of the characteristics OH1 and OH2 is the maximum heating capacity, and therefore, in most cases, the heating capacity required for the actual air conditioning load L is not insufficient. S Set to the outside air temperature T X When the outside air temperature is lower than the predetermined temperature difference Δx, the operation in the heat pump mode HP can be continued as economically as possible even if the outside air temperature decreases.

[0073] And, switch the outside air temperature T S It can also be set based on the maximum air conditioning load to the outside air temperature T from the intersection point X Intersection point X max The outside air temperature (T S ′). Intersection point X max L is the maximum air conditioning load assuming the introduction of external air and the maximum air volume max Intersection point with characteristic OH1.

[0074] [Second Modification] The temperature control system 1 of the above embodiment may include Figure 7 The heater pattern for startup shown is the startup heater pattern HT0.

[0075] For example, assuming that the temperature control system 1 is started after the vehicle has been stopped for a long time, the start-up heater mode HT0 and the heater mode HT are described. After the temperature control system 1 is started, the control device 5 preferably implements the start-up heater mode HT0 before the heater mode HT. This allows the heating operation to be started in advance.

[0076] When the temperature control system 1 is started after the vehicle has been stopped for a long time, when the outside air temperature is significantly lower than 0°C, the temperature of the heating medium is also as low as the outside air temperature. Therefore, just after the temperature control system 1 is started, the refrigerant is cooled by the heating medium, so that the low pressure of the refrigerant circuit 10 drops, and the evaporation temperature of the refrigerant is lower than the outside air temperature. Therefore, when the temperature control system 1 is started, the refrigerant can be heated by transferring the heat absorbed from the outside air to the heating medium by the outdoor heat exchanger 23 to the refrigerant through the heater mode HT0 at startup, taking precedence over the heating in the machine room 8. Then, the low pressure of the refrigerant circuit 10 rises to the specified value, and the refrigerant circuit 10 operates stably, 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.

[0077] [Description of heater mode at startup] refer to Figure 7 , together with the specific flow of the heating medium, the function of the startup heater mode HT0 using the series circuit CC is described. In the startup heater mode HT0, in order to allow the heating medium to absorb heat from the outside air through the outdoor heat exchanger 23, the heating medium is caused to flow into the outdoor heat exchanger 23. In addition, in order to give priority to the heating of the refrigerant over the heating in the machine room 8, the heating medium is not caused to flow into the condenser 12 but to bypass the condenser bypass path 12A, thereby preventing the refrigerant from radiating heat to the heating medium. Then, in the evaporator 14, the heat is radiated from the heating medium to the refrigerant. Furthermore, in order to suppress heat exchange between the air and the heating medium in the indoor heat exchanger 25, it is preferable to stop the operation of the indoor air-sending fan 25A.

[0078] In the startup heater mode HT0 , since the heating medium is detoured from the condenser 12 , the pressure loss of the heating medium is smaller than when the heating medium flows through the condenser 12 .

[0079] The heating medium flowing out of the evaporator 14 flows into the outdoor heat exchanger 23 via the second switching valve 32, and absorbs heat from the outside air. Figure 7In the figure, a heat medium that is heated by absorbing heat from the outside air is represented by a single-dot chain line. The heat medium flowing out of the outdoor heat exchanger 23 flows into the condenser bypass path 12A via the first switching valve 31 and the condenser flow regulating valve 12V, thereby bypassing the condenser 12. The heat medium flowing out of the condenser bypass path 12A flows into the indoor heat exchanger 25 via the third switching valve 33. However, since the indoor air blower 25A is stopped, the heat exchange between the heat medium in the indoor heat exchanger 25 and the cold air that is not conditioned is suppressed. The heat medium flowing out of the indoor heat exchanger 25 returns to the evaporator 14 via the first switching valve 31 and the evaporator flow regulating valve 14V. Then, it dissipates heat to the refrigerant through the evaporator 14, becomes a low-temperature heat medium, and flows out of the evaporator 14.

[0080] 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.

[0081] When the vehicle is stopped in a state where the outside air temperature is very low and below freezing, the temperatures of the heating medium and the refrigerant drop to the same level as the outside air temperature. Therefore, by starting the temperature control system 1, the compressor 11 starts to start, and when the refrigeration cycle just starts, the refrigerant cools the heating medium. However, according to the heater mode HT0 at startup, the heat absorbed from the outside air to the heating medium is continuously transferred to the refrigerant, and the low pressure of the refrigerant circuit 10 gradually increases, and the evaporation temperature also increases. In this process, the temperature of the heating medium that exchanges heat with the refrigerant also increases.

[0082] If the temperature of the heating medium exceeds the outside air temperature, the heat absorption from the outside air becomes insufficient. Therefore, the control device 5 can make the temperature control system 1 close to the outside air temperature and shift to the heater mode HT. For example, when the temperature of the heating medium exceeds a predetermined temperature difference threshold value t lower than the outside air temperature (e.g., -20°C) by α, the temperature control system 1 is switched to the heater mode HT. 3 The difference between the outside air temperature and the threshold value is determined by the temperature difference corresponding to the time required to switch the flow of the heating medium relative to the instruction to switch the operation mode.

[0083] When the heating operation is selected by the occupant's operation or by the temperature control system 1, the control device 5 can switch the outside air temperature T according to the mode selection unit 50. S The heat pump mode HP or the heater mode HT is selected by comparing with the outside air temperature T. Furthermore, if the outside air temperature T is higher than the switching outside air temperature T SLow threshold t 2 (e.g. -15°C), the control device 5 can select the heat pump mode HP, if the outside air temperature T is lower than the threshold value t 2 , the control device 5 can select the heater mode HT0 at startup.

[0084] If the detected outside air temperature T is lower than the switching outside air temperature T S , and after the temperature control system 1 is just started, the control device 5 does not need to compare the external air temperature T with the threshold value t 2 For comparison, the start-up heater mode HT0 can be selected before the heater mode HT. Alternatively, the start-up heater mode HT0 can be selected before the heater mode HT. S In the case of the heater mode HT being selected immediately after startup, a predetermined threshold is applied to the detected temperature of the heating medium or refrigerant to determine whether to continue the heater mode HT or switch to the startup heater mode HT0.

[0085] When the startup heater mode HT0 is performed before the heater mode HT, the controller 5 operates the temperature control system 1 in the startup heater mode HT0 while waiting for the refrigerant circuit 10 to reach a stable state position. For example, if the temperature of the heating medium exceeds a predetermined threshold value t 3 , the operation mode can be switched from the startup heater mode HT0 to the steady state heater mode HT. The threshold is not limited to the temperature of the heating medium or refrigerant, and a physical quantity such as pressure in the same state as the state of the heating medium or refrigerant indicated by the temperature threshold can also be used. After switching from the heater mode HT0 at startup to the heater mode HT, the flow rate of the heating medium flowing into the condenser 12 can be gradually increased by the condenser flow rate regulating valve 12V.

[0086] 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. 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.

[0087] [Note] Through the above disclosure, the structure described below will be understood. [1] A temperature control system for a vehicle, 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 first pump 21 and the second pump 22 are both configured to be able to pressure-feed 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 to heat or cool the temperature control object; and The outdoor heat exchanger bypass path 24 allows the heat medium to bypass the outdoor heat exchanger 23. The temperature control system has the following modes as operating modes: Heat pump mode HP, forming a low-pressure side circuit C1 in which the heat medium circulates through the low-pressure side heat exchanger 14 and the outdoor heat exchanger 23 through the first pump 21, and a high-pressure side circuit C2 in which the heat medium circulates through the high-pressure side heat exchanger 12 and the temperature control device 25 through the second pump 22; and In the compressor heat source mode HT, 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 heat exchanger bypass path 24. The temperature control system also has: a mode selection unit 50 configured to be able to select the heat pump mode HP or the compressor heat source mode HT; and The outside air temperature sensor 51 detects the outside air temperature. The mode selection unit 50 is configured as follows: The outside air temperature T is set to correspond to the intersection X of the outside air temperature-heating capacity characteristics OH1 and OH2 of the heat pump mode HP and the compressor heat source mode HT, respectively. X , or than the outside air temperature T of the intersection X Low temperature switching outside air temperature T S , T SL When the outside air temperature T detected by the outside air temperature sensor 51 is high, the heat pump mode HP is selected, and when the outside air temperature T is low, the compressor heat source mode HT is selected.

[0088] [2] The vehicle temperature control system according to [1], wherein: The mode selection unit 50 is configured to select the heat pump mode HP in a region R1 where the heating capacity CP in the outdoor air temperature-heating capacity characteristic OH1 is lower than that in the compressor heat source mode HT according to the heating load L. 1 , L 2 To set the switching outside air temperature T SL .

[0089] [3] The vehicle temperature control system according to [2], wherein: In the outside air temperature-heating capacity characteristic OH1 of the heat pump mode HP, the heating capacity CP decreases as the outside air temperature T decreases. The structure is such that, with respect to the heating load L 1 , L 2 and the switching outside air temperature T corresponding to the intersection points X1 and X2 of the outside air temperature-heating capacity characteristics of the heat pump mode HP. SL When the outside air temperature T is high, the heat pump mode HP is selected, and when the outside air temperature T is low, the compressor heat source mode HT is selected.

[0090] [4] The vehicle temperature control system according to any one of [1] to [3], comprising: A high-pressure side bypass path 12A allows the heat medium to bypass the high-pressure side heat exchanger 12; and The high-pressure side flow rate regulating valve 12V is configured to be able to adjust the flow rate ratio of the heat medium in the high-pressure side heat exchanger 12 and the high-pressure side bypass path. The vehicle temperature control system includes a startup compressor heat source mode HT0 as the operation mode. In the compressor heat source mode HT0 during startup, the heat carrier flowing out of the high-pressure side heat exchanger 12 flows into the low-pressure side heat exchanger 14, then passes through the outdoor heat exchanger 23, and flows into the high-pressure side heat exchanger 12 and at least the high-pressure side bypass path 12A.

[0091] [5] The vehicle temperature control system according to [4], wherein: The startup compressor heat source mode HT0 causes the heating medium flowing out of the low-pressure side heat exchanger 14 to flow into the outdoor heat exchanger 23 . [6] A vehicle temperature control method, which is a temperature control method using a vehicle temperature control system, The temperature control system 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 first pump 21 and the second pump 22 are both configured to be able to pressure-feed 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 to heat or cool the temperature control object; and The outdoor heat exchanger bypass path 24 allows the heat medium to bypass the outdoor heat exchanger 23. When the temperature control method is selected in the following modes: Heat pump mode HP, forming a low-pressure side circuit C1 in which the heat medium circulates through the low-pressure side heat exchanger 14 and the outdoor heat exchanger 23 through the first pump 21, and a high-pressure side circuit C2 in which the heat medium circulates through the high-pressure side heat exchanger 12 and the temperature control device 25 through the second pump 22; and In the compressor heat source mode HT, 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 heat exchanger bypass path 24. The outside air temperature T is set to correspond to the intersection X of the outside air temperature-heating capacity characteristics OH1 and OH2 of the heat pump mode HP and the compressor heat source mode HT, respectively. X , or than the outside air temperature T of the intersection X Low temperature switching outside air temperature T S , T SL When the detected outside air temperature T is high, the heat pump mode HP is selected, and when the detected outside air temperature T is low, the compressor heat source mode HT is selected. Explanation of symbols

[0092] 1- Temperature control system, 5- Control device, 8- Machine room, 10- Refrigerant circuit, 11- Compressor, 12- Condenser, 12A- Condenser bypass path, 12V- Condenser flow control valve, 13- Expansion valve (pressure reducing part), 14- Evaporator, 14A- Evaporator bypass path, 14V- Evaporator flow control valve, 20- Heat medium circuit, 21- 1st pump, 22- 2nd pump, 23- Outdoor heat exchanger, 23A- Outdoor fan, 24- Outdoor heat exchanger bypass path, 25- Indoor heat exchanger, 25A- Indoor fan, 31- 32- 1-switching valve, 32-2nd switching valve, 33-3rd switching valve, 50-mode selection unit, 51-outside air temperature sensor, 52-room temperature sensor, 501-memory, 502-calculation unit, 503-storage unit, 504-input / output unit, C1-low-pressure side circuit, C2-high-pressure side circuit, CC-series circuit, CP-heating capacity, DT-related data, R1, R2-area, HP-heat pump mode, HT-heater mode (compressor heat source mode), HT0-starting heater mode (starting compressor heat source mode), L, L 1 , L 2 - Air conditioning load, OH1, OH2 - External air temperature - Heating capacity characteristics, T, T 1 , T 2 - Outside air temperature, T S , T SL - Switch outside air temperature, T X -Intersection outside air temperature, U - HVAC unit, X - intersection, Δx - temperature 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; The first pump and the second pump are both configured to be able to pressure-feed 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 to heat or cool the temperature control object; and The outdoor heat exchanger bypass path allows the heat medium to bypass the outdoor heat exchanger. The temperature control system has the following modes as operating modes: Heat pump mode, forming a low-pressure side circuit in which the heat medium circulates through the low-pressure side heat exchanger and the outdoor heat exchanger through the first pump, and a high-pressure side circuit in which the heat medium circulates through the high-pressure side heat exchanger and the temperature control device through the second pump; and In the compressor heat source mode, 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 heat exchanger bypass path. The temperature control system also has: a mode selection unit configured to be able to select the heat pump mode or the compressor heat source mode; and External air temperature sensor, detects external air temperature, The mode selection unit is configured as follows: With respect to an intersection external air temperature set to correspond to the intersection of the external air temperature-heating capacity characteristics of the heat pump mode and the compressor heat source mode, or a switching external air temperature set to a temperature lower than the intersection external air temperature, the heat pump mode is selected when the external air temperature detected by the external air temperature sensor is high, and the compressor heat source mode is selected when the external air temperature is low.

2. The vehicle temperature control system according to claim 1, wherein: The mode selection unit is configured to be able to set the switching outside air temperature according to a heating load in a region where the heating capacity of the outside air temperature-heating capacity characteristic of the heat pump mode is lower than that of the compressor heat source mode.

3. The vehicle temperature control system according to claim 2, wherein: In the outside air temperature-heating capacity characteristics of the heat pump mode, the heating capacity decreases as the outside air temperature decreases, The mode selection unit is configured to select the heat pump mode when the outside air temperature is high, and to select the compressor heat source mode when the outside air temperature is low, relative to the switching outside air temperature corresponding to the intersection of the heating load and the outside air temperature-heating capacity characteristics of the heat pump mode.

4. The vehicle temperature control system according to any one of claims 1 to 3, comprising: A high-pressure side bypass path allows the heat medium to bypass the high-pressure side heat exchanger; and The high-pressure side flow regulating valve is configured to be able to adjust the flow ratio of the heat medium in the high-pressure side heat exchanger and the high-pressure side bypass path, The vehicle temperature control system includes a startup compressor heat source mode as the operation mode. In the startup compressor heat source mode, the heating medium flowing out of the low-pressure side heat exchanger flows into the outdoor heat exchanger and further flows into the high-pressure side bypass path.

5. The vehicle temperature control system according to claim 4, wherein: An indoor heat exchanger is provided for exchanging heat between the delivered air and the heating medium. In the startup compressor heat source mode, the heating medium flowing through the high-pressure side bypass path flows into the outdoor heat exchanger and then returns to the low-pressure side heat exchanger.

6. A vehicle temperature control method, which is a temperature control method using a vehicle temperature control system, 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; The first pump and the second pump are both configured to be able to pressure-feed 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 to heat or cool the temperature control object; and The outdoor heat exchanger bypass path allows the heat medium to bypass the outdoor heat exchanger. When the temperature control method is selected in the following modes: Heat pump mode, forming a low-pressure side circuit in which the heat medium circulates through the low-pressure side heat exchanger and the outdoor heat exchanger through the first pump, and a high-pressure side circuit in which the heat medium circulates through the high-pressure side heat exchanger and the temperature control device through the second pump; and In the compressor heat source mode, 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 heat exchanger bypass path. Relative to the switching external air temperature set to an intersection external air temperature corresponding to the intersection of the external air temperature-heating capacity characteristics of the heat pump mode and the compressor heat source mode, or a temperature lower than the intersection external air temperature, the heat pump mode is selected when the detected external air temperature is high, and the compressor heat source mode is selected when the external air temperature is low.

Images