On-vehicle temperature control system

Abstract

To provide an on-vehicle temperature control system capable of suppressing insufficient cooling capability.SOLUTION: An on-vehicle temperature control system includes a low-temperature water cooling circuit and a high-temperature water cooling circuit capable of exchanging heat via a refrigerant circuit, and a low-temperature side heat exchanger provided on the low-temperature water cooling circuit and a high-temperature side heat exchanger provided on the high-temperature water cooling circuit have a common heat radiation part. Therein, exhaust heat suppression control which suppresses exhaust heat from the high-temperature heat exchanger is executed under such a prescribed condition as to give priority to cooling on a predetermined low-temperature water cooling circuit based on the state of the unit cooled by exhaust heat from the low-temperature heat exchanger.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an in-vehicle temperature control system.

Background Art

[0002] Patent Document 1 discloses a heat exchanger that performs heat exchange between a heat medium and air, and has a configuration in which a plurality of heat medium passages share heat dissipation fins and louvers.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the low-temperature side heat exchanger provided in the low-temperature water cooling circuit and the high-temperature side heat exchanger provided in the high-temperature water cooling circuit of the in-vehicle temperature control system are integrated in the above configuration, since heat dissipation in the high-temperature side heat exchanger with a large temperature difference from the outside air is physically prioritized, there is a concern about insufficient cooling capacity due to insufficient heat dissipation in the low-temperature side heat exchanger.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide an in-vehicle temperature control system capable of suppressing insufficient cooling capacity.

Means for Solving the Problems

[0006] In order to solve the above-described problems and achieve the object, an in-vehicle temperature control system according to the present invention includes a low-temperature water cooling circuit and a high-temperature water cooling circuit capable of exchanging heat via a refrigerant circuit, a low-temperature side heat exchanger provided in the low-temperature water cooling circuit, and a high-temperature side heat exchanger provided in the high-temperature water cooling circuit. The in-vehicle temperature control system having a common heat dissipation unit, based on the state of a unit cooled by the exhaust heat from the low-temperature side heat exchanger, under predetermined conditions that prioritize cooling in the low-temperature water cooling circuit, exhaust heat suppression control for suppressing the exhaust heat from the high-temperature side heat exchanger is executed.

[0007] As a result, the exhaust heat from the low-temperature side heat exchanger is promoted by the amount by which the exhaust heat from the high-temperature side heat exchanger is suppressed, and insufficient cooling capacity can be suppressed.

[0008] Further, in the above, the exhaust heat suppression control may be executed as control for suppressing the amount of heat transferred from the refrigerant circuit to the high-temperature water cooling circuit.

[0009] As a result, since the amount of heat transferred from the refrigerant circuit to the high-temperature water cooling circuit is suppressed, the exhaust heat from the high-temperature side heat exchanger can be suppressed.

[0010] Further, in the above, the exhaust heat suppression control may be executed as control for suppressing heat generation in the refrigerant circuit.

[0011] As a result, due to the suppression of heat generation in the refrigerant circuit, the heat rejection requirement from the refrigerant circuit to the high-temperature water cooling circuit decreases, so that the amount of heat transferred from the refrigerant circuit to the high-temperature water cooling circuit is reduced, and the exhaust heat from the high-temperature side heat exchanger can be suppressed.

[0012] Further, in the above, the control for suppressing heat generation in the refrigerant circuit may be executed by reducing the upper limit value of the rotational speed of a compressor provided in the refrigerant circuit and / or by forcibly performing internal air circulation as air conditioning in the vehicle interior.

[0013] As a result, by directly reducing the upper limit value of the rotational speed of the compressor or indirectly reducing the rotational speed of the compressor by forcibly performing the internal air circulation, the heat rejection requirement from the refrigerant circuit to the high-temperature water cooling circuit decreases. Therefore, the amount of heat transferred from the refrigerant circuit to the high-temperature water cooling circuit can be reduced, and heat rejection from the high-temperature side heat exchanger can be suppressed. Further, by combining directly reducing the upper limit value of the rotational speed of the compressor and forcibly performing the internal air circulation, it is possible to reduce the amount of heat transferred from the refrigerant circuit to the high-temperature water cooling circuit while avoiding a decrease in air conditioning performance as much as possible, and suppress heat rejection from the high-temperature side heat exchanger.

Effect of the Invention

[0014] The vehicle-mounted temperature control system according to the present invention has the effect that the heat rejection from the low-temperature side heat exchanger is promoted to the extent that the heat rejection from the high-temperature side heat exchanger is suppressed, and the lack of cooling capacity can be suppressed.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Mode for Carrying Out the Invention

[0016] Hereinafter, an embodiment of the vehicle-mounted temperature control system according to the present invention will be described. Note that the present invention is not limited by this embodiment.

[0017] FIG. 1 is a block diagram showing a schematic configuration of a vehicle-mounted temperature control system 1 according to an embodiment.

[0018] The in-vehicle temperature control system 1 according to the embodiment includes a low-temperature water cooling circuit 2, a refrigerant circuit 3, and a high-temperature water cooling circuit 4, and is mounted on a vehicle.

[0019] The low-temperature water cooling circuit 2 is a circuit that circulates cooling water as a heat medium through a flow path formed by a pipe or the like. It is composed of a low-temperature radiator 20, a first electric unit 21, a second electric unit 22, a water pump 23, a battery 24, a water pump 25, and the like. The low-temperature radiator 20 is a low-temperature heat exchanger that exchanges heat between the cooling water and the outside air to cool the cooling water. The first electric unit 21, the second electric unit 22, and the battery 24 can exhaust heat to the cooling water through a water jacket or the like that constitutes a part of the flow path of the cooling water. The water pumps 23 and 25 control the heat dissipation amount at the low-temperature radiator 20, the heat exhaust amount from the first electric unit 21, the second electric unit 22, and the battery 24 to the cooling water, and the heat transfer amount (heat absorption amount) to the refrigerant circuit 3 via the chiller 30 described later, etc., by adjusting the flow rate and flow volume of the cooling water. The temperature of the cooling water circulating in the low-temperature water cooling circuit 2 is usually maintained lower than the temperature of the cooling water circulating in the high-temperature water cooling circuit 4.

[0020] The low-temperature water cooling circuit 2 forms a circulation path for circulating the cooling water at least between the battery 24 and the chiller 30 by the water pump 25 in order to cool the battery 24 by transferring the heat transferred from the battery 24 to the cooling water to the refrigerant circuit 3 via the chiller 30. Also, the low-temperature water cooling circuit 2 forms a circulation path for circulating the cooling water at least between the low-temperature radiator 20, the first electric unit 21, and the second electric unit 22 by the water pump 23 in order to cool the first electric unit 21 and the second electric unit 22 by dissipating (exhausting) the heat transferred from the first electric unit 21 and the second electric unit 22 to the cooling water from the low-temperature radiator 20.

[0021] In the low-temperature water cooling circuit 2, devices cooled by heat dissipation (waste heat) in the low-temperature radiator 20 include, for example, motor generators and PCUs (such as inverters and DCDC converters) provided in each of the first electric unit 21 and the second electric unit 22, and a charger used for charging and discharging the battery 24 mounted on the vehicle. Note that the battery 24 of the low-temperature water cooling circuit 2 is cooled using the chiller 30 (finally, waste heat from the high-temperature radiator 40 of the high-temperature water cooling circuit 4), but it is not limited thereto. For example, when the battery 24 is directly cooled by the low-temperature water cooling circuit 2 by heat dissipation (waste heat) from the low-temperature radiator 20 of the low-temperature water cooling circuit 2, the battery 24 is also included in the devices cooled by the low-temperature radiator 20 of the low-temperature water cooling circuit 2.

[0022] The refrigerant circuit 3 is a circuit that circulates a refrigerant while changing its state as a heat medium, and is composed of a chiller 30, an evaporator 31, a compressor 32, a water-cooled condenser 33, and the like. In the refrigerant circuit 3, the refrigerant compressed by the compressor 32 is condensed by the water-cooled condenser 33, and the condensed refrigerant is injected into the evaporator 31 through an expansion valve provided in the evaporator 31 and expanded, so that heat can be absorbed from the air in the evaporator 31. The chiller 30 is a unit that can absorb heat from the cooling water of the low-temperature water cooling circuit 2 and discharge waste heat to the refrigerant. The evaporator 31 and the compressor 32 are units that can discharge waste heat to the refrigerant. The water-cooled condenser 33 is a unit that can absorb heat from the refrigerant and discharge waste heat to the cooling water of the high-temperature water cooling circuit 4. The refrigerant circuit 3 is coupled to the low-temperature water cooling circuit 2 via the chiller 30 so that the heat generated in the low-temperature water cooling circuit 2 can be transferred to the refrigerant circuit 3 via the chiller 30. Further, the refrigerant circuit 3 is coupled to the high-temperature water cooling circuit 4 via the water-cooled condenser 33 so that the heat generated in the refrigerant circuit 3 and / or the heat transferred from the low-temperature water cooling circuit 2 to the refrigerant circuit 3 can be transferred to the high-temperature water cooling circuit 4 via the water-cooled condenser 33.

[0023] The high-temperature water cooling circuit 4 is a circuit that circulates cooling water as a heat medium, and is composed of a high-temperature radiator 40, a water pump 41, an electric heater 42, a heater core 43, and the like. The high-temperature water cooling circuit 4 has a function of storing heat in the cooling water for heating as air conditioning in the vehicle interior, and a function of dissipating heat (exhaust heat) received from the refrigerant circuit 3 by heat exchange to the outside of the vehicle. The high-temperature radiator 40 is a high-temperature heat exchanger for performing heat exchange between the cooling water and the outside air to air-cool the cooling water. The water pump 41 is a unit that circulates the cooling water, and by adjusting the flow rate and flow volume of the cooling water, the heat dissipation amount (exhaust heat amount) of the high-temperature radiator 40 and the moving heat amount from the refrigerant circuit 3 through the water-cooled condenser 33 can be changed. The electric heater 42 is a unit that heats the cooling water when the temperature of the cooling water is insufficient. The heater core 43 has a tube and fins through which the cooling water flows, and is a unit that performs heat exchange between the air passing through the fins and the cooling water.

[0024] In the high-temperature water cooling circuit 4, the types of devices cooled by heat dissipation (exhaust heat) in the high-temperature radiator 40, and the direct or indirect exhaust heat include the compressor 32, evaporator heat absorption, and chiller heat absorption (= battery exhaust heat), etc. Note that as long as it is directly connected to the high-temperature water cooling circuit 4, such as engine exhaust heat, or indirectly exhausts heat from the high-temperature radiator 40 of the high-temperature water cooling circuit 4 via the high-temperature water cooling circuit 4, it does not matter whether it is direct or indirect.

[0025] Regarding the configurations of the low-temperature water cooling circuit 2 and the high-temperature water cooling circuit 4, as long as heat can be exhausted from the low-temperature radiator 20 and the high-temperature radiator 40, the circuit configuration is not particularly limited. For example, a configuration that enables each device to be cooled using a switching valve, and the arrangement order of the devices to be cooled, etc. are not particularly limited.

[0026] In the in-vehicle temperature control system 1 according to the embodiment, the low-temperature radiator 20 of the low-temperature water cooling circuit 2 and the high-temperature radiator 40 of the high-temperature water cooling circuit 4 are provided in proximity to each other, and have a structure in which a plurality of heat dissipation fins are shared in a common heat dissipation section. And, in the in-vehicle temperature control system 1 according to the embodiment, a mechanism is provided for temporarily restricting the exhaust heat at the high-temperature radiator 40 of the high-temperature water cooling circuit 4.

[0027] FIG. 2 is a diagram showing the restriction level of the exhaust heat at the high-temperature radiator 40 in the in-vehicle temperature control system 1 according to the embodiment. Note that the battery cooling level in FIG. 2 is the strength of the cooling requirement for the battery 24, and the higher the battery cell temperature of the battery 24, the stronger the requirement. Also, the unit cooling level in FIG. 2 is the strength of the cooling requirement for the first electric unit 21 and the second electric unit 22 (motor generator, PCU (inverter and DCDC converter, etc.), and charger, etc.) in the low-temperature water cooling circuit 2, and is determined by the target temperature of the cooling object, the temperature of the cooling water, the influence of the malfunctioning function, etc.

[0028] As shown in FIG. 2, in a region where the battery cooling level is low and the unit cooling level is low, the restriction level of the exhaust heat at the high-temperature radiator 40 is lowered to prioritize the air conditioning performance. Also, as shown in FIG. 2, in a region where the battery cooling level is high and the unit cooling level is low, the restriction level of the exhaust heat at the high-temperature radiator 40 is lowered to prioritize the cooling of the battery 24 via the chiller 30. Also, as shown in FIG. 2, in a region where the battery cooling level is low and the unit cooling level is high, the restriction level of the exhaust heat at the high-temperature radiator 40 is raised to promote the exhaust heat from the low-temperature water cooling circuit 2 and prioritize the cooling of the unit. Also, as shown in FIG. 2, in a region where the battery cooling level is high and the unit cooling level is high, the restriction level of the exhaust heat at the high-temperature radiator 40 is set to medium to balance the cooling of the unit and the cooling of the battery 24.

[0029] FIG. 3 is a flowchart showing an example of temperature control in the in-vehicle temperature control system 1 according to the embodiment. Note that the temperature control shown in FIG. 3 is executed, for example, by an electronic control unit mounted on the vehicle. Further, various information necessary for the electronic control unit to perform temperature control is acquired, for example, by various sensors provided in each of the low-temperature water cooling circuit 2, the refrigerant circuit 3, and the high-temperature water cooling circuit 4, and transmitted to the electronic control unit. Further, the electronic control unit can control the operations of various units (devices) such as the water pumps 23, 25, 41, the compressor 32, the electric heater 42, and the air conditioner provided in each of the low-temperature water cooling circuit 2, the refrigerant circuit 3, and the high-temperature water cooling circuit 4.

[0030] First, in the in-vehicle temperature control system 1, the electronic control unit calculates the battery cooling level (step S1). Next, in the in-vehicle temperature control system 1, the electronic control unit calculates the unit cooling level (step S2). Next, in the in-vehicle temperature control system 1, the electronic control unit calculates the radiator cooling level of the low-temperature water cooling circuit 2 (step S3). The radiator cooling level of the low-temperature water cooling circuit 2 is determined from the battery cooling level calculated in step S1 and the unit cooling level calculated in step S2. Increasing the radiator cooling level of the low-temperature water cooling circuit 2 partially restricts the cooling of the air conditioner (cooling or dehumidifying) that exhausts heat from the high-temperature radiator 40 of the high-temperature water cooling circuit 4 and the battery 24 using the chiller 30. Conversely, decreasing the radiator cooling level of the low-temperature water cooling circuit 2 relaxes the restriction on the cooling of the air conditioner (cooling or dehumidifying) that exhausts heat from the high-temperature radiator 40 of the high-temperature water cooling circuit 4 and the battery 24 using the chiller 30.

[0031] Next, in the in-vehicle temperature control system 1, the electronic control unit calculates the upper limit of the rotation speed of the compressor 32 in the refrigerant circuit 3 (step S4). The upper limit rotation speed of the compressor 32 is lowered according to the radiator cooling level of the low-temperature water cooling circuit 2. That is, when the radiator cooling level of the low-temperature water cooling circuit 2 is high, the upper limit rotation speed of the compressor 32 is decreased to limit the compressor work. Thereby, the heat absorption amount of the refrigerant circuit 3 can be reduced, and thus the heat exhaust amount of the high-temperature radiator 40 of the high-temperature water cooling circuit 4 can be reduced.

[0032] Next, in the vehicle air conditioning system 1, the electronic control unit determines whether to forcibly switch the air conditioning to the recirculation mode according to the radiator cooling level of the low-temperature water cooling circuit 2 (step S5). The forced recirculation mode of the air conditioning is performed when the radiator cooling level of the low-temperature water cooling circuit 2 is higher than the threshold value. In the vehicle air conditioning system 1, when the electronic control unit determines not to forcibly switch the air conditioning to the recirculation mode (No in step S5), it does not perform the forced recirculation mode and ends the series of controls. In the vehicle air conditioning system 1, when the electronic control unit determines to forcibly switch the air conditioning to the recirculation mode (Yes in step S5), the electronic control unit determines the forced recirculation mode (step S6) and performs the forced recirculation mode. By performing the forced recirculation mode, the heat absorption amount of the refrigerant circuit 3 can be reduced, and thus the heat rejection amount of the high-temperature radiator 40 on the high-temperature side of the high-temperature water cooling circuit 4 can be reduced. Then, in the vehicle air conditioning system 1, the series of controls are ended.

[0033] The vehicle air conditioning system 1 according to the embodiment includes a low-temperature water cooling circuit 2 and a high-temperature water cooling circuit 4 that can transfer heat to each other via the refrigerant circuit 3. The low-temperature radiator 20 provided in the low-temperature water cooling circuit 2 and the high-temperature radiator 40 provided in the high-temperature water cooling circuit 4 have a common heat dissipation part. In the vehicle air conditioning system 1 according to the embodiment, based on the state of the unit cooled by the heat dissipation (heat rejection) from the low-temperature radiator 20, under a predetermined condition that prioritizes the cooling in the predetermined low-temperature water cooling circuit 2 (low-temperature radiator 20), heat rejection suppression control for suppressing the heat rejection from the high-temperature radiator 40 is executed. Thereby, in the vehicle air conditioning system 1 according to the embodiment, the heat rejection from the low-temperature radiator 20 of the low-temperature water cooling circuit 2 is promoted by the amount by which the heat rejection from the high-temperature radiator 40 of the high-temperature water cooling circuit 4 is suppressed, and insufficient cooling capacity can be suppressed.

[0034] Also, in the in-vehicle temperature control system 1 according to the embodiment, the exhaust heat suppression control may be executed as control for suppressing the amount of heat transferred from the refrigerant circuit 3 to the high-temperature water cooling circuit 4. Thereby, since the amount of heat transferred from the refrigerant circuit 3 to the high-temperature water cooling circuit 4 is suppressed, the exhaust heat from the high-temperature side radiator 40 can be suppressed.

[0035] Also, in the in-vehicle temperature control system 1 according to the embodiment, the exhaust heat suppression control may be executed as control for suppressing heat generation in the refrigerant circuit 3. Thereby, due to the suppression of heat generation in the refrigerant circuit 3, the exhaust heat demand from the refrigerant circuit 3 to the high-temperature water cooling circuit 4 decreases, so that the amount of heat transferred from the refrigerant circuit 3 to the high-temperature water cooling circuit 4 can be reduced, and the exhaust heat from the high-temperature side radiator 40 can be suppressed.

[0036] Also, in the in-vehicle temperature control system 1 according to the embodiment, the control for suppressing heat generation in the refrigerant circuit 3 may be executed by lowering the upper limit value of the rotational speed of the compressor 32 provided in the refrigerant circuit 3 and / or forcibly performing internal air circulation as the air conditioning in the vehicle interior. Thereby, due to the direct lowering of the upper limit value of the rotational speed of the compressor 32 or the indirect lowering of the rotational speed of the compressor by forcibly performing internal air circulation, the exhaust heat demand from the refrigerant circuit 3 to the high-temperature water cooling circuit 4 decreases, so that the amount of heat transferred from the refrigerant circuit 3 to the high-temperature water cooling circuit 4 can be reduced, and the exhaust heat from the high-temperature side radiator 40 can be suppressed. Also, by combining the direct lowering of the upper limit value of the rotational speed of the compressor 32 and the forcible execution of internal air circulation, while avoiding a decrease in air conditioning performance as much as possible, the amount of heat transferred from the refrigerant circuit 3 to the high-temperature water cooling circuit 4 can be reduced, and the exhaust heat from the high-temperature side radiator 40 can be suppressed.

[0037] In the in-vehicle temperature control system 1 according to the embodiment, for example, a mechanism is provided to limit the compressor operation and the heat absorption amount of the evaporator 31 in the refrigerant circuit 3. However, the mechanism for limiting the waste heat from the high-temperature radiator 40 in the high-temperature water cooling circuit 4 is not particularly limited. That is, it may be switched to a method of using a cooling device that does not inhibit the waste heat of the low-temperature radiator 20 in the low-temperature water cooling circuit 2 other than the high-temperature radiator 40 in the high-temperature water cooling circuit 4, or a method of discharging heat to another heat utilization destination. Further, a method such as reducing the output of the water pump 41 in the high-temperature water cooling circuit 4 to reduce the cooling water circulation amount in the high-temperature water cooling circuit 4 and thereby reducing the efficiency of the high-temperature radiator 40 in the high-temperature water cooling circuit 4 may also be used.

Explanation of Signs

[0038] 1 In-vehicle temperature control system 2 Low-temperature water cooling circuit 3 Refrigerant circuit 4 High-temperature water cooling circuit 20 Low-temperature radiator 21 First electric unit 22 Second electric unit 23 Water pump 24 Battery 25 Water pump 30 Chiller 31 Evaporator 32 Compressor 33 Water-cooled condenser 40 High-temperature radiator 41 Water pump 42 Electric heater 43 Heater core

Claims

1. The cooling system includes a low-temperature water cooling circuit and a high-temperature water cooling circuit capable of transferring heat through a refrigerant circuit, A vehicle-mounted temperature control system, wherein a low-temperature side heat exchanger provided in the low-temperature water cooling circuit and a high-temperature side heat exchanger provided in the high-temperature water cooling circuit have a common heat dissipation part, An in-vehicle temperature control system characterized by executing exhaust heat suppression control to suppress exhaust heat from the high-temperature side heat exchanger under predetermined conditions that prioritize cooling in the low-temperature water cooling circuit based on the state of a unit cooled by exhaust heat from the low-temperature side heat exchanger.

2. 2. The vehicle-mounted temperature adjustment system according to claim 1, wherein the exhaust heat suppression control is executed as a control for suppressing an amount of heat transferred from the refrigerant circuit to the high-temperature water cooling circuit.

3. 3. The vehicle-mounted temperature adjustment system according to claim 2, wherein the exhaust heat suppression control is executed as a control for suppressing heat generation in the refrigerant circuit.

4. The vehicle temperature control system according to claim 3, characterized in that the control for suppressing heat generation in the refrigerant circuit is performed by lowering the upper limit of the rotation speed of a compressor provided in the refrigerant circuit and / or by forcibly circulating internal air as air conditioning for the vehicle cabin.

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