JP2014213667A - Chiller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chiller capable of decreasing the frequency of heat exchange between cooling liquid and air-conditioning refrigerant while ensuring cooling performance of a heating element.SOLUTION: Each of flow path switching units 24 and 25 can switch over between a first cooling mode of connecting a heating element-side flow path 12 to a heat exchanger-side flow path 20 and connecting a radiator-side flow path 16 to a circulation flow path 22 and a second cooling mode of connecting the heating element-side flow path 12 to the radiator-side flow path 16. If a temperature T1 of a heating element 10 is equal to or higher than a set temperature, the flow path switching units 24 and 25 select the first cooling mode. If a temperature T2 of cooling water passing through a radiator 14 falls to be equal to or lower than a reference temperature Tref while the first cooling mode is selected, the flow path switching units 24 and 25 switch the first cooling mode to the second cooling mode.

Description

  The present invention relates to a cooling device that cools a heating element with a coolant.

  A cooling device according to Patent Document 1 below includes a radiator, a coolant circulation circuit in which a heat generating part is configured in a closed circuit, an air conditioning refrigerant circulation circuit having an evaporator for an air conditioner and a compressor, a coolant circulation circuit, and an air conditioner. A heat exchanger that exchanges heat with the refrigerant circuit. When the demand for cooling the heat generating part becomes high, the cooling performance of the heat generating part is secured by switching the air conditioning refrigerant path of the air conditioning refrigerant circulation circuit to the path where the heat exchanger exists. .

JP 2002-352866 A JP 2011-105150 A

  In Patent Document 1, when the cooling requirement of the heat generating part is high, it is necessary to always operate the compressor of the air-conditioning refrigerant circulation circuit and perform heat exchange between the air-conditioning refrigerant and the coolant with the heat exchanger. As a result, the power consumption due to the operation of the compressor of the air conditioning refrigerant circulation circuit increases.

  The present invention relates to a cooling device that releases heat of a cooling liquid for cooling a heating element by heat exchange with a radiator or an air conditioning refrigerant, while ensuring the cooling performance of the heating element, and the heat of the cooling liquid and the air conditioning refrigerant. The purpose is to reduce the frequency of exchanges.

  The cooling device according to the present invention employs the following means in order to achieve the above-described object.

  The cooling device according to the present invention is configured to flow the cooling liquid through the heating element side path for cooling the heating element by flowing the cooling liquid, the radiator for releasing the heat of the cooling liquid, and the radiator. Radiator side path, a heat exchanger for exchanging heat between the coolant and the air conditioning refrigerant, a heat exchanger side path for allowing the coolant to flow through the heat exchanger, and the heating element side path And a circulation path for circulating the coolant flowing through the radiator side path without passing through the heat exchanger side path, and the heating element side path connected to the heat exchanger side path and the radiator side path Path switching means capable of switching between a first state connected to the circulation path and a second state connecting the heating element side path to the radiator side path, and the path switching means includes the heating element Or said When the temperature of the coolant that cools the heat body is equal to or higher than the set temperature, the first state is selected, and the temperature of the coolant that passes through the radiator is the reference when the first state is selected. The gist is to switch to the second state when the temperature becomes lower than the temperature.

  According to the present invention, at the time of selecting the first state, the heat of the cooling water circulating in the closed circuit by the radiator, the radiator side path, and the circulation path can be released by the radiator to promote the temperature decrease. When the temperature of the coolant passing through the radiator becomes equal to or lower than the reference temperature, the heat is exchanged between the coolant and the air conditioning refrigerant while ensuring the cooling performance of the heating element by switching to the second state. The frequency can be reduced.

It is a figure which shows schematic structure of the cooling device which concerns on embodiment of this invention. It is a figure which shows the 1st cooling mode of the cooling device which concerns on embodiment of this invention. It is a figure which shows the 2nd cooling mode of the cooling device which concerns on embodiment of this invention. It is a flowchart explaining an example of the process which an electronic controller performs. It is a flowchart explaining the other example of the process which an electronic controller performs.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings.

  FIG. 1 is a diagram showing a schematic configuration of a cooling device according to an embodiment of the present invention. A water pump 11 is provided in the heating element side flow path 12, and by driving the water pump 11, it is possible to flow cooling water (cooling liquid) through the heating element side flow path 12. The cooling water flowing through the heating element side flow path 12 can cool the heating element 10 that is a cooling target. Although the kind of heat generating body 10 here is not specifically limited, As a specific example, the power control unit (PCU) for hybrid vehicles which has a power element, the battery for hybrid vehicles, etc. are mentioned.

  The heat exchanger 18 releases heat of the cooling water by exchanging heat between the cooling water flowing inside and the refrigerant of the air conditioner 26 (air conditioning refrigerant). The heat exchanger side flow path 20 is a flow path for supplying and discharging cooling water to and from the heat exchanger 18 and allowing the coolant to flow through the heat exchanger 18. When heat exchange between the cooling water and the air conditioning refrigerant is performed by the heat exchanger 18, the compressor (compressor) of the air conditioner 26 is operated to supply the air conditioning refrigerant to the heat exchanger 18. On the other hand, when the heat exchanger 18 does not perform heat exchange between the cooling water and the air conditioning refrigerant, the compressor of the air conditioner 26 is stopped and the air conditioning refrigerant is not supplied to the heat exchanger 18.

  The radiator 14 releases heat of the cooling water to the outside by performing heat exchange between the cooling water flowing inside and the outside air. The radiator side flow path 16 is a flow path for supplying and discharging cooling water to and from the radiator 14 and allowing the coolant to flow through the radiator 14. The radiator side flow path 16 is provided with a cooling water tank 17 and a water pump 15 for storing cooling water. By driving the water pump 15, the cooling water in the cooling water tank 17 is supplied to the radiator side flow path 16. It is possible to flow to. The circulation flow path 22 is a flow path for circulating the coolant flowing through the radiator side flow path 16 without passing through the heating element side flow path 12 and the heat exchanger side flow path 20.

  The flow path switching devices 24 and 25 connect the heating element side flow path 12 to the heat exchanger side flow path 20 (heat exchanger 18) and connect the radiator side flow path 16 to the circulation flow path 22 in the first cooling mode. (First state) and a second cooling mode (second state) in which the heating element side flow path 12 is connected to the radiator side flow path 16 can be switched. The flow path switching device 24 includes open / close valves 24a, 24b, and 24c, and the flow path switching device 25 includes open / close valves 25a, 25b, and 25c. The first cooling mode is selected by opening the on-off valves 24a, 24c, 25a, 25c and closing the on-off valves 24b, 25b. In the first cooling mode, as shown in FIG. 2, a cooling circuit for circulating the cooling water between the heating element side flow path 12 and the heat exchanger 18 is formed, and the radiator 14 (radiator side flow path) is formed. A closed circuit for circulating the cooling water flowing through 16) through the circulation channel 22 without passing through the heating element side channel 12 and the heat exchanger side channel 20 is formed. On the other hand, the second cooling mode is selected by opening the on-off valves 24b and 25b and closing the on-off valves 24a, 24c, 25a and 25c. In the second cooling mode, as shown in FIG. 3, a cooling circuit for circulating the cooling water between the heating element side flow path 12 and the radiator 14 is formed. In the second cooling mode, the connection between the heat exchanger side flow path 20 and the other flow paths is disconnected, and the connection between the circulation flow path 22 and the other flow paths is also disconnected.

  When the first cooling mode is selected by the flow path switching devices 24 and 25, the water pump 11 is driven to circulate the cooling water between the heating element side flow path 12 and the heat exchanger 18, thereby generating heat. The body 10 can be cooled. In that case, the heat of the cooling water for cooling the heating element 10 is released by operating the compressor of the air conditioner 26 and supplying the air conditioning refrigerant to the heat exchanger 18 to exchange heat with the cooling water. To do. Furthermore, by driving the water pump 15, the cooling water can be circulated between the radiator 14 and the circulation passage 22 without passing through the heating element side passage 12 and the heat exchanger side passage 20, The heat of the circulating cooling water can be released by the radiator 14.

  On the other hand, when the second cooling mode is selected by the flow path switching devices 24 and 25, the water pump 11 or the water pump 15 is driven to circulate the cooling water between the heating element side flow path 12 and the radiator 14. Thus, the heating element 10 can be cooled. In that case, since the heat of the cooling water for cooling the heating element 10 is released by the radiator 14, the compressor of the air conditioner 26 is stopped and the air conditioning refrigerant is not supplied to the heat exchanger 18.

  The temperature sensor 27 detects the temperature T1 of the heating element 10. The temperature sensor 28 detects the temperature T2 of the cooling water that passes through the radiator 14. The temperatures T1 and T2 detected by the temperature sensors 27 and 28 are input to an electronic control unit (ECU) 30. The electronic control device 30 performs switching control between the first cooling mode and the second cooling mode by the flow path switching devices 24 and 25. Hereinafter, processing executed by the electronic control unit 30 will be described with reference to the flowchart of FIG. The flowchart of FIG. 4 is repeatedly executed every predetermined time, and the second cooling mode is selected in the initial state.

  In the flowchart of FIG. 4, in step S <b> 101, it is determined whether or not the second cooling mode is selected by the flow path switching devices 24 and 25. When the first cooling mode is selected (when the determination result of step S101 is NO), the process proceeds to step S102, and when the second cooling mode is selected (when the determination result of step S101 is YES). The process proceeds to step S104.

  In step S102, it is determined whether or not the temperature of the cooling water detected by the temperature sensor 28 (the temperature of the cooling water passing through the radiator 14) T2 is equal to or lower than the reference temperature Tref. When the cooling water temperature T2 is higher than the reference temperature Tref (when the determination result of step S102 is NO), the process proceeds to step S103, and when the cooling water temperature T2 is equal to or lower than the reference temperature Tref (the determination result of step S102 is YES). In the case of (), the process proceeds to step S106.

  In step S103, it is determined whether or not the temperature T1 of the heating element 10 detected by the temperature sensor 27 is equal to or higher than the set temperature Tset1. When the temperature T1 of the heating element 10 is equal to or higher than the set temperature Tset1 (when the determination result of step S103 is YES), the process proceeds to step S105, and when the temperature T1 of the heating element 10 is lower than the set temperature Tset1 (in step S103) If the determination result is NO), the process proceeds to step S106.

  In step S104, it is determined whether or not the temperature T1 of the heating element 10 detected by the temperature sensor 27 is equal to or higher than the set temperature Tset2 (Tset2> Tset1, Tset2> Tref). When the temperature T1 of the heating element 10 is equal to or higher than the set temperature Tset2 (when the determination result in step S104 is YES), the process proceeds to step S105, and when the temperature T1 of the heating element 10 is lower than the set temperature Tset2 (in step S104). If the determination result is NO), the process proceeds to step S106.

  In step S105, the first cooling mode is selected by the flow path switching devices 24 and 25. When the first cooling mode is already selected, the first cooling mode is maintained, and when the second cooling mode is selected, the first cooling mode is switched from the second cooling mode by the flow path switching devices 24 and 25. Can be switched to.

  In step S106, the second cooling mode is selected by the flow path switching devices 24, 25. When the second cooling mode is already selected, the second cooling mode is maintained. When the first cooling mode is selected, the flow path switching devices 24 and 25 change the first cooling mode to the second cooling mode. Can be switched to.

  In step S102, the temperature T1 of the heating element 10 or the temperature of the cooling water passing through the heat exchanger 18 (for example, detected by a temperature sensor) can be used as the reference temperature Tref. In steps S103 and S104, instead of the temperature T1 of the heating element 10, the temperature of the cooling water for cooling the heating element 10 (for example, detected by a temperature sensor) can be used.

  According to the process of the flowchart of FIG. 4, when the temperature T1 of the heating element 10 (or the temperature of the cooling water for cooling the heating element 10) is equal to or higher than the set temperature, the first cooling is performed by the flow path switching devices 24 and 25. A mode is selected. When the first cooling mode is selected and the heating element 10 is cooled by the cooling water circulating between the heating element side passage 12 and the heat exchanger 18, the radiator 14, the radiator side passage 16, and the circulation passage By circulating a predetermined amount of cooling water in the closed circuit 22, the heat of the cooling water in the closed circuit can be released by the radiator 14 to promote a temperature drop. And when the temperature of the cooling water passing through the radiator 14 (the temperature of the cooling water in the closed circuit) T2 falls below the reference temperature Tref, the flow path switching devices 24 and 25 change the first cooling mode to the second cooling mode. By switching to, it is possible to reduce the selection frequency of the first cooling mode and increase the selection frequency of the second cooling mode while ensuring the cooling performance of the heating element 10. When the second cooling mode is selected and the heating element 10 is cooled by the cooling water circulating between the heating element side flow path 12 and the radiator 14, the heating element 10 is operated without operating the compressor of the air conditioner 26. Cooling can be performed. Accordingly, the frequency of stopping the compressor of the air conditioner 26 can be increased (the frequency of heat exchange between the cooling water and the air conditioning refrigerant in the heat exchanger 18 can be reduced), and the electricity generated by the operation of the compressor of the air conditioner 26 can be reduced. Consumption can be reduced.

  The electronic control device 30 can also perform switching control between the first cooling mode and the second cooling mode by the flow path switching devices 24 and 25 according to the processing of the flowchart of FIG. In the flowchart of FIG. 5, in step S201, the temperature T2 of the cooling water passing through the radiator 14 is read, and in step S202, the temperature T3 of the cooling water passing through the heat exchanger 18 (for example, detected by a temperature sensor) is read. . In step S203, it is determined whether or not the temperature T2 of the cooling water passing through the radiator 14 is lower than the temperature T3 of the cooling water passing through the heat exchanger 18. In the case of T2 <T3 (when the determination result in step S203 is YES), the cooling water passing through the radiator 14 has higher cooling performance than the cooling water passing through the heat exchanger 18; The second cooling mode is selected by the path switching devices 24 and 25. On the other hand, when T2 ≧ T3 (when the determination result in step S203 is NO), in step S205, the coolant temperature T2 after the second cooling mode is selected is estimated, and in step S206, the coolant temperature T2 is determined to be outside air. It is determined whether or not the temperature is lower than the temperature Tout (for example, detected by a temperature sensor). When T2 <Tout (when the determination result in step S206 is YES), the cooling water passing through the radiator 14 absorbs heat from the outside air and rises in temperature, so in step S207, the flow path switching devices 24 and 25 perform the first operation. A cooling mode is selected. On the other hand, when T2 ≧ Tout (when the determination result of step S206 is NO), in step S208, the coolant temperature T2 after the second cooling mode is selected is estimated, and in step S209, the coolant temperature T2 is cooled. It is determined whether or not it is lower than the possible water temperature Tp. When the heating element 10 is a battery, for example, the coolable water temperature Tp is set from the cell temperature, and when the heating element 10 is a power control unit, for example, an absolute value is set as the coolingable water temperature Tp for determination. When T2 ≧ Tp (when the determination result of step S209 is NO), it is difficult to ensure the cooling performance in the second cooling mode. Therefore, in step S210, the first cooling mode is set by the flow path switching devices 24 and 25. Selected. On the other hand, when T2 <Tp (when the determination result of step S209 is YES), the second cooling mode is selected by the flow path switching devices 24 and 25 in step S211.

  Even in the process of the flowchart of FIG. 5, when the first cooling mode is selected, a predetermined amount of cooling water is circulated in the closed circuit by the radiator 14, the radiator-side flow path 16, and the circulation flow path 22. The cooling water can be released by the radiator 14 to promote a temperature drop, and the frequency of selecting the first cooling mode can be reduced. As a result, the frequency of stopping the compressor of the air conditioner 26 can be increased.

  As mentioned above, although the form for implementing this invention was demonstrated, this invention is not limited to such embodiment at all, and it can implement with a various form in the range which does not deviate from the summary of this invention. Of course.

  DESCRIPTION OF SYMBOLS 10 Heating body, 11, 15 Water pump, 12 Heating body side flow path, 14 Radiator, 16 Radiator side flow path, 17 Cooling water tank, 18 Heat exchanger, 20 Heat exchanger side flow path, 22 Circulation flow path, 24 , 25 Channel switching device, 24a, 24b, 24c, 25a, 25b, 25c On-off valve, 26 Air conditioning device, 27, 28 Temperature sensor, 30 Electronic control device.

Claims (1)

A heating element side path for cooling the heating element by flowing a cooling liquid;
A radiator for releasing the heat of the coolant,
A radiator side path for allowing the coolant to flow through the radiator;
A heat exchanger for performing heat exchange between the coolant and the air conditioning refrigerant;
A heat exchanger side path for flowing coolant through the heat exchanger;
A circulation path for circulating the coolant flowing through the radiator side path without passing through the heating element side path and the heat exchanger side path;
Switch between a first state in which the heating element side path is connected to the heat exchanger side path and the radiator side path is connected to the circulation path, and a second state in which the heating element side path is connected to the radiator side path. Possible route switching means;
Have
The route switching means is
When the temperature of the heating element or the cooling liquid for cooling the heating element is equal to or higher than a set temperature, the first state is selected,
A cooling device that switches to the second state when the temperature of the coolant that passes through the radiator becomes a reference temperature or lower when the first state is selected.

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