Heat utilization loop

Abstract

The present disclosure relates to a heat utilization circuit that efficiently utilizes heat exchanged by a cooling medium that cools a plurality of objects to be cooled. In the heat utilization circuit (2), when the temperature of the cooling medium after cooling the drive axle (26) is equal to or higher than the temperature of the cooling medium after cooling the inverter (21), heat exchange is performed between the cooling medium after cooling the inverter (21) and the drive axle (26). When the temperature of the cooling medium after cooling the drive axle (26) is lower than the temperature of the cooling medium after cooling the inverter (21), heat exchange between the cooling medium after cooling the inverter (21) and the drive axle (26) is suppressed.

Description

Technical Field

[0001] This disclosure relates to heat utilization circuits. Background Technology

[0002] It is known that a heating object is heated by utilizing the heat from a cooling medium after the object has been cooled in a vehicle. Patent Document 1 discloses the use of an inverter as the heat source in a cooling unit for heating.

[0003] Prior art literature

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2020-165604 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] Patent Document 1 only discloses the inverter as the cooling object, and does not disclose the heat utilization of the cooling medium when multiple cooling objects are configured. When the heating rates of multiple cooling objects are different, it is sometimes not efficient to heat the heated object by utilizing the heat of the cooling medium after cooling multiple cooling objects. For example, if the cooling medium that has heated up by cooling a cooling object with a relatively fast heating rate is used to cool a cooling object with a relatively slow heating rate, heat loss may occur, and the heating efficiency of the heated object may decrease.

[0008] The purpose of this disclosure is to efficiently utilize the heat exchanged by the cooling medium that cools multiple objects.

[0009] Methods for solving problems

[0010] This disclosure provides a heat recovery circuit, comprising: a first cooling flow path through which a cooling medium for cooling an inverter flows; and a second cooling flow path through which a cooling medium for cooling a drive axle flows. In the heat recovery circuit, when the temperature of the cooling medium after cooling the drive axle is higher than the temperature of the cooling medium after cooling the inverter, heat exchange occurs between the cooling medium after cooling the inverter and the drive axle; when the temperature of the cooling medium after cooling the drive axle is lower than the temperature of the cooling medium after cooling the inverter, heat exchange between the cooling medium after cooling the inverter and the drive axle is suppressed.

[0011] Invention Effects

[0012] According to this disclosure, the heat exchanged by the cooling medium that cools multiple objects can be efficiently utilized. Attached Figure Description

[0013] Figure 1 This is a diagram illustrating the structure of the heat utilization circuit in this embodiment.

[0014] Figure 2 It is used for explanation Figure 1 The flowchart shown illustrates the operation of the heat utilization circuit.

[0015] Figure 3 This is a diagram illustrating the structure of the heat utilization circuit in a modified example of this embodiment.

[0016] Figure 4 This is a diagram illustrating the structure of the heat utilization circuit in a modified example of this embodiment.

[0017] Figure 5 This is a diagram illustrating the structure of the heat utilization circuit in a modified example of this embodiment.

[0018] Figure 6 This is a diagram illustrating the structure of the heat utilization circuit in a modified example of this embodiment.

[0019] Explanation of reference numerals in the attached figures

[0020] 2: Heat Utilization Circuit

[0021] 21: Inverter

[0022] 24: Switching valve

[0023] 25: Oil cooler

[0024] 26: Drive axle

[0025] 201, 201A, 201B: first cooling flow path

[0026] 202, 202A, 202B: Second cooling flow path

[0027] 201a, 202Aa: Heat utilization flow path

[0028] 201b, 202Ab: Heat exchange flow path

[0029] 201c, 202Ac, 203B: Bypass Flow Path

[0030] 401: Refrigerant Circuit

[0031] 501: Cooling water circuit. Detailed Implementation

[0032] Hereinafter, this embodiment will be described with reference to the accompanying drawings. In order to facilitate understanding of the description, the same reference numerals will be used as much as possible for the same constituent elements in each drawing, and repeated descriptions will be omitted.

[0033] Reference Figure 1 The heat utilization circuit 2 of this embodiment will now be described. The heat utilization circuit 2 is a heat exchange system installed in a vehicle. The heat utilization circuit 2 includes a first cooling flow path 201 and a second cooling flow path 202.

[0034] The first cooling flow path 201 is a flow path through which the cooling medium for cooling the inverter 21 flows. In this embodiment, the cooling medium for cooling the inverter 21 is water. The first cooling flow path 201 includes a heat recovery flow path 201a, a heat exchange flow path 201b, and a bypass flow path 201c.

[0035] Both ends of the heat recovery flow path 201a are connected to both ends of the heat exchange flow path 201b, forming a flow path for circulating the cooling medium. A switching valve 24, acting as a three-way valve, is installed at the portion where one end of the heat recovery flow path 201a connects to one end of the heat exchange flow path 201b. The other end of the heat recovery flow path 201a is connected to the other end of the heat exchange flow path 201b at a connection point P1. A bypass flow path 201c is provided such that the switching valve 24 is connected to the connection point P1.

[0036] A pump 23 is provided to circulate the cooling medium in the first cooling flow path 201. In this embodiment, the pump 23 is provided in the heat recovery flow path 201a. A temperature sensor 28 is provided in the first cooling flow path 201 to measure the temperature of the cooling medium after cooling the inverter 21. In this embodiment, the temperature sensor 28 is provided downstream of the inverter 21 in the heat recovery flow path 201a.

[0037] An inverter 21 and a battery 22 are configured in the heat recovery flow path 201a. The inverter 21 is cooled by a cooling medium flowing in the heat recovery flow path 201a. The cooling medium, which raises the temperature of the inverter 21 by cooling it, exchanges heat with the battery 22, causing the battery 22 to heat up as well.

[0038] An oil cooler 25 is provided in the heat exchange flow path 201b. The oil cooler 25 is a heat exchanger used for heat exchange between the oil cooler 25 and the cooling medium flowing in the second cooling flow path 202.

[0039] The second cooling flow path 202 is a flow path for the cooling medium to flow to cool the drive axle 26. In this embodiment, the cooling medium for cooling the drive axle 26 is oil.

[0040] A drive axle 26, a pump 27, a temperature sensor 29, and an oil cooler 25 are arranged in the second cooling flow path 202. The pump 27 is configured to circulate the cooling medium within the second cooling flow path 202. The temperature sensor 29 is located downstream of the drive axle 26 and upstream of the oil cooler 25 to measure the temperature of the cooling medium after cooling the drive axle 26. The oil cooler 25 is a heat exchanger used for heat exchange between the oil cooler 25 and the cooling medium flowing in the first cooling flow path 201.

[0041] As an electrical component, the control unit 3 includes a microcomputer (hereinafter referred to as "microcomputer"), a data transmission circuit, a power supply circuit, and a power detection circuit. The microcomputer includes a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), and flash memory.

[0042] Temperature data showing the temperature of the cooling medium after cooling the inverter 21 is input to the control unit 3 from temperature sensor 28. Temperature data showing the temperature of the cooling medium after cooling the drive axle 26 is input to the control unit 3 from temperature sensor 29. The control unit 3 outputs drive signals to pump 23, switching valve 24, and pump 27.

[0043] Next, refer to Figure 2 The operation of control unit 3 will be explained below. In step S01, control unit 3 acquires the drive axle side temperature and the inverter side temperature. The drive axle side temperature is the temperature of the cooling medium after cooling the drive axle 26, and is the temperature data output by temperature sensor 29. The inverter side temperature is the temperature of the cooling medium after cooling the inverter, and is the temperature data output by temperature sensor 28.

[0044] In step S02, immediately following step S01, the control unit 3 determines whether the drive bridge side temperature is below the inverter side temperature. If the drive bridge side temperature is below the inverter side temperature (step S02: "Yes"), the processing proceeds to step S03. If the drive bridge side temperature is not below the inverter side temperature (step S02: "No"), the processing proceeds to step S05.

[0045] In step S03, the control unit 3 determines whether to suppress heat exchange between the cooling medium after cooling the inverter 21 and the drive bridge 26. Figure 1In the heat utilization loop 2 shown, heat exchange occurs between the cooling medium after cooling the inverter 21 and the drive bridge 26. Therefore, the control unit 3 determines whether to suppress heat exchange between the cooling medium after cooling the inverter 21 and the cooling medium after cooling the drive bridge 26. (Referring to...) Figure 2 In the explanation provided, the control unit 3 determines whether to stop the heat exchange between the cooling medium used to cool the inverter 21 and the cooling medium used to cool the drive axle 26.

[0046] In step S04, immediately following step S03, control unit 3 adjusts switching valve 24 to allow the cooling medium after cooling inverter 21 to dominate the temperature rise of battery 22 disposed in heat recovery flow path 201a. Dominating the temperature rise of battery 22 disposed in heat recovery flow path 201a using cooling medium after cooling inverter 21 means that more cooling medium that cools inverter 21 and does not pass through oil cooler 25 flows to battery 22 compared to cooling medium that passes through oil cooler 25. (Refer to...) Figure 2 In the explanation provided, the control unit 3 switches the switching valve 24 so that all the cooling medium after cooling the inverter 21 flows to the bypass flow path 201c.

[0047] In step S05, the control unit 3 determines whether heat exchange has been performed between the cooling medium after cooling the inverter 21 and the drive bridge 26. Figure 1 In the heat utilization circuit 2 shown, the heat exchange between the cooling medium that cools the inverter 21 and the drive bridge 26 occurs between the cooling medium that cools the inverter 21 and the cooling medium that cools the drive bridge 26. Therefore, the control unit 3 determines whether to implement the heat exchange between the cooling medium that cools the inverter 21 and the cooling medium that cools the drive bridge 26.

[0048] In step S06, immediately following step S05, control unit 3 adjusts switching valve 24 to utilize the temperature rise caused by the cooling medium after cooling inverter 21 and the temperature rise caused by the cooling medium after cooling drive axle 26, which is then used in battery 22 configured in heat recovery flow path 201a. (Refer to...) Figure 2 In the described embodiment, the control unit 3 switches the switching valve 24 so that all the cooling medium after cooling the inverter 21 flows to the heat exchange path 201b. Alternatively, the control unit 3 can switch the switching valve 24 so that the cooling medium after cooling the inverter 21 flows separately to the heat exchange path 201b and the bypass path 201c.

[0049] In reference Figure 1 In the heat utilization circuit 2 described herein, the bypass flow path 201c is provided in the first cooling flow path 201, but the bypass flow path can also be provided in the second cooling flow path. (Refer to...) Figure 3 The heat utilization circuit 2A, which is a modified example in which a bypass flow path is provided in the second cooling flow path, will be described. When describing the heat utilization circuit 2A, descriptions of parts common to the heat utilization circuit 2 will be appropriately omitted; the main focus will be on the differences from the heat utilization circuit 2. The heat utilization circuit 2A includes a first cooling flow path 201A and a second cooling flow path 202A.

[0050] The first cooling flow path 201A is a flow path for the cooling medium to flow to cool the inverter 21. The first cooling flow path 201A is equipped with the inverter 21, pump 23, temperature sensor 28, battery 22 and oil cooler 25.

[0051] The inverter 21 is cooled by the cooling medium flowing in the first cooling flow path 201A. The cooling medium, which is heated by cooling the inverter 21, is further heated by heat exchange in the oil cooler 25 and exchanges heat with the battery 22, thereby heating the battery 22.

[0052] The second cooling flow path 202A is a flow path for the cooling medium to flow to cool the drive axle 26. The second cooling flow path 202A has a heat recovery flow path 202Aa, a heat exchange flow path 202Ab, and a bypass flow path 202Ac.

[0053] Both ends of the heat recovery flow path 202Aa are connected to both ends of the heat exchange flow path 202Ab, forming a flow path for circulating the cooling medium. A switching valve 24 is installed at one end of the heat recovery flow path 202Aa, where it connects to one end of the heat exchange flow path 202Ab. The other end of the heat recovery flow path 202Aa is connected to the other end of the heat exchange flow path 202Ab at the connection point P2. A bypass flow path 202Ac is provided such that the switching valve 24 is connected to the connection point P2.

[0054] A pump 27 is provided to circulate the cooling medium in the second cooling flow path 202A. In this modified example, the pump 27 is provided in the heat recovery flow path 202Aa. A temperature sensor 29 is provided in the second cooling flow path 202 to measure the temperature of the cooling medium after cooling the drive axle 26. In this modified example, the temperature sensor 29 is provided downstream of the drive axle 26 in the heat recovery flow path 202Aa.

[0055] An oil cooler 25 is provided in the heat exchange flow path 202Ab. The oil cooler 25 is a heat exchanger used for heat exchange between the oil cooler 25 and the cooling medium flowing in the first cooling flow path 201A.

[0056] Regarding the operation of the control unit 3 in the heat utilization circuit 2A, refer to Figure 2 The steps S01, S02, S03, and S05 described are the same as those in heat utilization circuit 2.

[0057] In step S04, the control unit 3 adjusts the switching valve 24 to allow the cooling medium after cooling the inverter 21 to dominate the temperature rise of the battery 22 configured in the first cooling flow path 201A. Dominating the temperature rise of the battery 22 configured in the first cooling flow path 201A using the cooling medium after cooling the inverter 21 means suppressing heat exchange between the cooling medium after cooling the inverter 21 in the oil cooler 25 and the cooling medium flowing in the second cooling flow path 202A, allowing it to flow directly to the battery 22. For example, the control unit 3 switches the switching valve 24 so that all the cooling medium after cooling the drive axle 26 flows into the bypass flow path 202Ac.

[0058] In step S06, the control unit 3 adjusts the switching valve 24 to utilize the temperature rise caused by the cooling medium after cooling the inverter 21 and the cooling medium after cooling the drive axle 26 for the battery 22 disposed in the first cooling flow path 201A. For example, the control unit 3 switches the switching valve 24 so that all the cooling medium after cooling the drive axle 26 flows to the heat exchange flow path 202Ab. Alternatively, the control unit 3 may switch the switching valve 24 so that the cooling medium after cooling the drive axle 26 flows separately to the heat exchange flow path 202Ab and the bypass flow path 202Ac.

[0059] In reference Figure 1 The heat utilization circuit 2 is explained in reference. Figure 3 In the heat utilization circuit 2A, an example of using oil as the cooling medium to cool the drive axle 26 is described. Water can also be used as the cooling medium to cool the drive axle 26; in this case, it can be shared with the cooling medium used to cool the inverter 21. For the heat utilization circuit 2B, which uses water as the cooling medium to cool the drive axle 26, please refer to... Figure 4 Explanation will be provided. When explaining the heat utilization circuit 2B, the explanation of the parts common to heat utilization circuit 2 will be appropriately omitted, and the main focus will be on the differences between it and heat utilization circuit 2.

[0060] like Figure 4As shown, the heat utilization circuit 2B includes a first cooling flow path 201B and a second cooling flow path 202B. The two ends of the first cooling flow path 201B are connected to the two ends of the second cooling flow path 202B, and the first cooling flow path 201B and the second cooling flow path 202B form a flow path for circulating water as a cooling medium.

[0061] A switching valve 24 is provided at one end of the first cooling flow path 201B and one end of the second cooling flow path 202B. The other end of the first cooling flow path 201B and the other end of the second cooling flow path 202B are connected at the connecting part P3. A bypass flow path 203B is provided such that the switching valve 24 is connected to the connecting part P2.

[0062] An inverter 21, a pump 23, a temperature sensor 28, and a battery 22 are configured in the first cooling flow path 201B. The inverter 21 is cooled by a cooling medium flowing in the first cooling flow path 201B. The cooling medium, heated by cooling the inverter 21, exchanges heat with the battery 22, further heating the battery 22. When the heated cooling medium flows to the second cooling flow path 202B, it further cools and heats the drive axle 26. When the heated cooling medium flows to the bypass flow path 203B, it directly heats the battery 22.

[0063] A drive axle 26 and a temperature sensor 29 are arranged in the second cooling flow path 202B. The temperature sensor 29 is provided in the second cooling flow path 202B to measure the temperature of the cooling medium after cooling the drive axle 26. In this modified example, the temperature sensor 29 is provided at a position downstream of the drive axle 26.

[0064] Regarding the operation of the control unit 3 in the heat utilization circuit 2B, refer to Figure 2 The steps S01, S02, S03, and S05 described are the same as those in heat utilization circuit 2.

[0065] In step S04, the control unit 3 adjusts the switching valve 24 to allow the cooling medium after cooling the inverter 21 to dominate the temperature rise of the battery 22 configured in the first cooling flow path 201B. Dominating the temperature rise of the battery 22 configured in the first cooling flow path 201B using the cooling medium after cooling the inverter 21 means suppressing heat exchange between the cooling medium after cooling the inverter 21 and the drive bridge 26, allowing it to flow to the battery 22. For example, the control unit 3 switches the switching valve 24 so that all the cooling medium after cooling the drive bridge 26 flows to the bypass flow path 203B.

[0066] In step S06, the control unit 3 adjusts the switching valve 24 to divert the temperature rise caused by the cooling medium after cooling the inverter 21 and the temperature rise caused by the cooling medium after cooling the drive axle 26 to the battery 22. For example, the control unit 3 switches the switching valve 24 so that all the cooling medium after cooling the inverter 21 flows to the second cooling flow path 202B. Alternatively, the control unit 3 may switch the switching valve 24 so that the cooling medium after cooling the inverter 21 flows separately to the second cooling flow path 202B and the bypass flow path 203B.

[0067] Reference Figure 1 , 2 Sections 3 and 4 describe the structure of a heat utilization circuit in which the heat recovered from cooling the inverter and drive axle is transferred to the battery. However, the form of heat transfer is not limited to directly supplying the battery. In addition, heat can also be supplied to elements other than the battery.

[0068] exist Figure 5 In the heat utilization circuit 2C shown, instead of the reference... Figure 1 The heat utilization circuit 2, as described above, is equipped with a cooler 41 for the battery 22, and also includes a refrigerant circuit 401 and a cooling water circuit 501. The refrigerant circuit 401 functions as a heat pump. The refrigerant circuit 401 is equipped with a cooler 41, a compressor 42, and a water-cooled condenser 43.

[0069] The refrigerant circulating in the refrigerant circuit 401 receives heat in the cooler 41, is pressurized by the compressor 42 to further increase its temperature, and flows into the water-cooled condenser 43. In the water-cooled condenser 43, it exchanges heat with the cooling water flowing in the cooling water circuit 501.

[0070] The cooling water circuit 501 is equipped with a water-cooled condenser 43, a pump 51, and a battery 22. The cooling water circulating in the cooling water circuit 501 undergoes heat exchange with the water-cooled condenser 43, which raises the temperature of the battery 22.

[0071] The control unit 3 outputs control signals to pump 23, switching valve 24, pump 27, compressor 42 and pump 51.

[0072] The heat recovery circuit 2C recovers heat from the inverter 21 and drive bridge 26 and heats the battery 22 via the refrigerant circuit 401, which acts as a heat pump.

[0073] exist Figure 6 In the heat utilization loop 2D shown, the reference is... Figure 5In the heat utilization circuit 2C, the battery 22 is replaced by a heater core 52. As with the heat utilization circuit 2D, it is also possible that heat is not provided to the battery 22, but to other heating objects such as the heater core 52.

[0074] The present embodiment has been described above with reference to specific examples. However, this disclosure is not limited to these specific examples. Structures obtained by those skilled in the art through appropriate design modifications to these specific examples, as long as they possess the features of this disclosure, are also included within the scope of this disclosure. The elements, their configurations, conditions, shapes, etc., of each of the above-described specific examples are not limited to the illustrated cases and can be appropriately modified. The combinations of the elements of each of the above-described specific examples can be appropriately changed as long as no technical contradictions arise.

[0075] [Note]

[0076] For notes 1 to 4 below, any combination is permissible as long as there is no technical contradiction.

[0077] [Note 1]

[0078] The heat utilization circuits 2, 2A, 2B, 2C, and 2D include: first cooling flow paths 201, 201A, and 201B, through which cooling medium flows to cool the inverter 21; and second cooling flow paths 202, 202A, and 202B, through which cooling medium flows to cool the drive axle 26. In the heat utilization circuits 2, 2A, 2B, 2C, and 2D, when the temperature of the cooling medium after cooling the drive axle 26 is higher than the temperature of the cooling medium after cooling the inverter 21, heat exchange occurs between the cooling medium after cooling the inverter 21 and the drive axle 26; when the temperature of the cooling medium after cooling the drive axle 26 is lower than the temperature of the cooling medium after cooling the inverter 21, heat exchange between the cooling medium after cooling the inverter 21 and the drive axle 26 is suppressed.

[0079] Compared to the inverter 21, the drive axle 26 has a larger heat capacity in the heat transfer path from the heat-generating part to the cooling medium. Therefore, even if the temperature of the drive axle 26 itself rises, it sometimes takes a relatively long time before the cooling medium heats up. According to Note 1, when the temperature of the cooling medium after cooling the drive axle 26 is lower than the temperature of the cooling medium after cooling the inverter 21, heat exchange between the cooling medium after cooling the inverter 21 and the drive axle 26 is suppressed. Therefore, the temperature drop of the cooling medium heated by cooling the inverter 21 due to heat exchange with the drive axle 26 can be suppressed, and the heat of the cooling medium heated by heat exchange with the inverter 21 can be effectively utilized.

[0080] [Note 2]

[0081] Based on the heat utilization circuits 2, 2A, 2C, and 2D described in Note 1, a first cooling medium for cooling the inverter flows in the first cooling flow path 201 and 201A, and a second cooling medium for cooling the drive axle flows in the second cooling flow path 202 and 202A. The heat utilization circuits 2, 2A, 2C, and 2D also include an oil cooler 25 as a heat exchanger for heat exchange between the first and second cooling media. Heat exchange in the heat exchanger occurs when the temperature of the second cooling medium after cooling the drive axle 26 is higher than the temperature of the first cooling medium after cooling the inverter 21, and heat exchange in the heat exchanger is suppressed when the temperature of the second cooling medium after cooling the drive axle 26 is lower than the temperature of the first cooling medium after cooling the inverter 21.

[0082] According to Note 2, since the oil cooler 25 is provided as a heat exchanger for heat exchange between the first cooling medium and the second cooling medium, the first cooling medium and the second cooling medium can be different, and a cooling medium suitable for the object being cooled can be used.

[0083] [Note 3]

[0084] Based on the heat utilization circuits 2, 2A, 2C, and 2D described in Note 2, the first cooling flow path 201, 201A and / or the second cooling flow path 202, 202A include: heat exchange flow paths 201b and 202Ab, which pass through an oil cooler 25 serving as a heat exchanger; bypass flow paths 201c and 202Ac, which do not pass through the oil cooler 25 serving as a heat exchanger; and a switching valve 24, which controls whether to allow the first cooling medium and / or the second cooling medium to flow to the heat exchange flow path 201b or 202Ab, or to allow the first cooling medium to flow to the second cooling medium. The medium and / or the second cooling medium flows to the bypass flow path 201c, 202Ac for switching. When the temperature of the second cooling medium after cooling the drive axle 26 is higher than the temperature of the first cooling medium after cooling the inverter 21, the switching valve 24 causes the first cooling medium and / or the second cooling medium to flow to the heat exchange flow path 201b, 202Ab. When the temperature of the second cooling medium after cooling the drive axle 26 is lower than the temperature of the first cooling medium after cooling the inverter 21, the switching valve 24 increases the amount of the first cooling medium and / or the second cooling medium flowing to the bypass flow path 201c, 202Ac.

[0085] According to Note 3, when the temperature of the second cooling medium after cooling the drive axle 26 is lower than the temperature of the first cooling medium after cooling the inverter 21, the amount of the first cooling medium and / or the second cooling medium flowing into the bypass paths 201c and 202Ac is increased. Therefore, the temperature of the cooling medium heated while cooling the inverter 21 can be reliably suppressed from decreasing due to heat exchange with the drive axle 26, and the heat of the cooling medium heated by heat exchange with the inverter 21 can be effectively utilized.

[0086] [Note 4]

[0087] Based on the heat utilization circuit 2B described in Note 1, the same cooling medium flows in the first cooling flow path 201B and the second cooling flow path 202B. The heat utilization circuit 2B further includes: a bypass flow path 203B, which prevents the cooling medium after cooling the inverter 21 from passing through the drive bridge 26; and a switching valve 24, which switches whether the cooling medium flows to the second cooling flow path 202B or the bypass flow path 203B. When the temperature of the cooling medium after cooling the drive bridge 26 is higher than the temperature of the cooling medium after cooling the inverter 21, the switching valve 24 allows the cooling medium after cooling the inverter 21 to flow to the second cooling flow path 202B. When the temperature of the cooling medium after cooling the drive bridge 26 is lower than the temperature of the cooling medium after cooling the inverter 21, the switching valve 24 increases the amount of cooling medium after cooling the inverter 21 flowing to the bypass flow path 203B.

[0088] According to Note 4, even if the same cooling medium flows in the first cooling flow path 201B and the second cooling flow path 202B, by setting a simple structure such as the bypass flow path 203B and the switching valve 24, it is possible to suppress the temperature drop of the cooling medium heated by cooling the inverter 21 due to heat exchange with the drive bridge 26, and to effectively utilize the heat of the cooling medium that has been heated by heat exchange with the inverter 21.

Claims

1. A heat utilization circuit, wherein, The heat utilization circuit includes: A first cooling flow path, wherein a cooling medium flows through the first cooling flow path to cool the inverter; and The second cooling flow path supplies the cooling medium for cooling the drive axle. When the temperature of the cooling medium after cooling the drive axle is higher than the temperature of the cooling medium after cooling the inverter, heat exchange occurs between the cooling medium after cooling the inverter and the drive axle. When the temperature of the cooling medium after cooling the drive axle is lower than the temperature of the cooling medium after cooling the inverter, heat exchange between the cooling medium after cooling the inverter and the drive axle is suppressed.

2. The heat utilization circuit according to claim 1, wherein, A first cooling medium for cooling the inverter flows in the first cooling flow path. A second cooling medium for cooling the drive axle flows in the second cooling flow path. The heat utilization circuit also includes a heat exchanger, which performs heat exchange between the first cooling medium and the second cooling medium. Heat exchange occurs in the heat exchanger when the temperature of the second cooling medium after cooling the drive axle is above the temperature of the first cooling medium after cooling the inverter. When the temperature of the second cooling medium after cooling the drive axle is lower than the temperature of the first cooling medium after cooling the inverter, heat exchange in the heat exchanger is suppressed.

3. The heat utilization circuit according to claim 2, wherein, The first cooling flow path and / or the second cooling flow path includes: a heat exchange flow path via the heat exchanger; a bypass flow path that does not pass through the heat exchanger; and a switching valve that switches whether the first cooling medium and / or the second cooling medium flows into the heat exchange flow path or into the bypass flow path. When the temperature of the second cooling medium after cooling the drive axle is higher than the temperature of the first cooling medium after cooling the inverter, the switching valve allows the first cooling medium and / or the second cooling medium to flow into the heat exchange path. When the temperature of the second cooling medium after cooling the drive axle is lower than the temperature of the first cooling medium after cooling the inverter, the switching valve increases the amount of the first cooling medium and / or the second cooling medium flowing into the bypass path.

4. The heat utilization circuit according to claim 1, wherein, The same cooling medium flows in both the first and second cooling paths. The heat utilization circuit further includes: a bypass path that prevents the cooling medium after cooling the inverter from passing through the drive bridge; and a switching valve that switches whether the cooling medium flows to the second cooling path or to the bypass path. When the temperature of the cooling medium after cooling the drive axle is higher than the temperature of the cooling medium after cooling the inverter, the switching valve allows the cooling medium after cooling the inverter to flow into the second cooling path. When the temperature of the cooling medium after cooling the drive axle is lower than the temperature of the cooling medium after cooling the inverter, the switching valve increases the amount of cooling medium after cooling the inverter flowing into the bypass path.

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