Vehicle thermal management system

Abstract

The objective is to provide a vehicle thermal management system capable of improving the heat exchange efficiency of two adjacent heat exchangers. [Solution] Based on the operating status of the air conditioning system, the control unit 24 switches the switching unit 22 so that, in heating operation, coolant flows from the first connection part 16A to the LT radiator 14 and not from the second connection part 16B. On the other hand, in operation other than heating operation, the switching unit 22 switches so that coolant flows from the second connection part 16B to the LT radiator 14 and not from the first connection part 16A.

Description

Technical Field

[0001] The present invention relates to a vehicle thermal management device.

Background Art

[0002] In Patent Document 1, in the cooling mode, an air / refrigerant heat exchanger that exchanges heat between air and refrigerant dissipates heat from the refrigerant through an air / cooling water heat exchanger that exchanges heat between air and cooling water. In the heating mode, the air / cooling water heat exchanger is configured such that the cooling water absorbs heat through the air / refrigerant heat exchanger. An in-vehicle thermal management device is disclosed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the technology of Patent Document 1, in the cooling mode, heat can be dissipated from the refrigerant in the air / refrigerant heat exchanger to the air flow, and in the heating mode, the cooling water in the air / cooling water heat exchanger can absorb heat from the air flow. However, in the two heat exchangers arranged adjacent to each other, the heat exchanger on the rear side of the vehicle is affected by the ambient temperature of the heat exchanger on the front side of the vehicle, and there is a temperature distribution in the heat exchanger on the front side of the vehicle. Therefore, there is room for improvement to improve the heat exchange efficiency.

[0005] In consideration of the above facts, the present invention is made, and an object thereof is to provide a vehicle thermal management device capable of improving the heat exchange efficiency of the heat exchanger on the rear side of the vehicle among two adjacent heat exchangers.

Means for Solving the Problems

[0006] The vehicle thermal management device according to the first embodiment includes a first heat exchanger located at the front of the vehicle, a second heat exchanger located adjacent to the rear of the first heat exchanger, an air conditioning device that air-conditions the interior of the vehicle using a refrigerant circulating within the first heat exchanger, an outlet connected to the refrigerant outlet of the second heat exchanger, a first connection connected to a refrigerant inlet located at the top of the second heat exchanger, a second connection connected to a refrigerant inlet located in the center of the second heat exchanger, and a switching unit that switches the flow of refrigerant to the first and second connection based on the operating status of the air conditioning device, and a cooling circuit connected to the second heat exchanger through which the refrigerant flows.

[0007] According to the first embodiment, the switching unit is capable of switching the refrigerant path of the second heat exchanger between a path in which the refrigerant flows from the first connection to the refrigerant outlet and a path in which the refrigerant flows from the second connection to the refrigerant outlet, based on the operating status of the air conditioning system. This makes it possible to make maximum use of the second heat exchanger and improve the heat exchange efficiency of the heat exchanger on the rear side of the vehicle, of the two heat exchangers arranged adjacent to each other.

[0008] The vehicle thermal management device according to the second embodiment further comprises a control unit that controls the switching unit based on the operating status of the air conditioning system, in addition to the vehicle thermal management device according to the first embodiment.

[0009] According to the second embodiment, the control unit can change the refrigerant path of the second heat exchanger to a refrigerant path suitable for cooling, heating, etc., by controlling the switching unit based on the operating status of the air conditioning system.

[0010] In the vehicle thermal management device according to the third embodiment, the control unit controls the switching unit so that when the air conditioning device is in heating operation, the refrigerant flows from the first connection unit to the second heat exchanger.

[0011] According to the third embodiment, in the case of heating operation, by controlling the switching unit so that the refrigerant flows from the first connection unit to the second heat exchanger, heat can be transferred to the first heat exchanger using the entire surface of the second heat exchanger, thereby improving the heating performance of the air conditioning system.

[0012] The vehicle thermal management device according to the fourth embodiment is a vehicle thermal management device according to the second or third embodiment, wherein the control unit controls the switching unit so that when the air conditioning device is not operating in heating mode, the refrigerant flows from the second connection unit into the second heat exchanger.

[0013] According to the fourth embodiment, when not in heating operation, the switching unit is controlled so that the refrigerant flows from the second connection unit into the second heat exchanger, thereby reducing the influence of the high-temperature portion of the first heat exchanger and allowing heat to be dissipated from the second heat exchanger. [Effects of the Invention]

[0014] As described above, the present invention provides a vehicle thermal management device that can improve the heat exchange efficiency of the heat exchanger on the rear side of two adjacent heat exchangers. [Brief explanation of the drawing]

[0015] [Figure 1] This is a schematic diagram showing the general configuration of the vehicle thermal management system according to this embodiment. [Figure 2] This is a perspective view showing the LT radiator. [Figure 3] This is a schematic diagram showing the switching state of the switching mechanism during winter. [Figure 4] This is a schematic diagram showing the switching state of the switching mechanism during the summer. [Figure 5] This flowchart shows an example of the processing flow performed in the control unit of the vehicle thermal management system according to this embodiment. [Figure 6] This figure shows the temperature distribution of the HT radiator and LT radiator, and the coolant flow of the LT radiator, when the system is not in heating operation. [Figure 7] This figure shows the temperature distribution of the HT radiator and LT radiator, and the coolant flow of the LT radiator during heating operation. [Modes for carrying out the invention]

[0016] Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram showing a schematic configuration of a vehicle thermal management device 10 according to the present embodiment.

[0017] The vehicle thermal management device 10 according to the present embodiment includes an HT (High Temperature) radiator 12 as an example of a first heat exchanger and an LT (Low Temperature) radiator 14 as an example of a second exchanger. The HT radiator 12 and the LT radiator 14 are arranged adjacent to each other along the vehicle front-rear direction.

[0018] The HT radiator 12 is arranged at the front of the vehicle. In the present embodiment, a cross-flow type heat exchanger is applied to the HT radiator 12. The HT radiator 12 cools, for example, a battery, an air conditioner, etc. as an object to be cooled. The HT radiator 12 has a function of cooling the object to be cooled by allowing cooling water, which is an example of a refrigerant, to flow therethrough. Further, the HT radiator 12 is connected to a heater core (not shown) provided in the vehicle interior, and has a function of heating the vehicle interior by radiating the heat of the cooling water from the heater core during heating. Note that a refrigerant other than cooling water may be applied as the refrigerant flowing through the HT radiator 12.

[0019] The LT radiator 14 is arranged adjacent to the rear side of the vehicle of the HT radiator 12. In the present embodiment, a cross-flow type heat exchanger is applied to the LT radiator 14. A cooling circuit 16 through which cooling water, which is an example of a refrigerant, flows is connected to the LT radiator 14. In the present embodiment, the LT radiator 14 functions as a heat absorber during heating operation, and the heat absorbed for heating is utilized. Note that a refrigerant other than cooling water may be applied as the refrigerant flowing through the LT radiator 14.

[0020] As shown in FIG. 2, the LT radiator 14 has two refrigerant inlets 14A and 14B on one end side in the vehicle width direction and one refrigerant outlet 14C at the lower part on the other end side in the vehicle width direction. One of the refrigerant inlets 14A on one end side in the vehicle width direction is provided at the upper part of the LT radiator 14, and the other refrigerant inlet 14B is provided at the central part in the vertical direction of the LT radiator 14. Note that the central part is not limited to the middle in the vertical direction, and it may be above or below the middle.

[0021] In this embodiment, since the LT radiator 14 applies a cross-flow type, cooling water flows in from one of the two refrigerant inlets 14A and 14B on one end side in the vehicle width direction, and as shown by the dotted arrow in FIG. 2, the cooling water circulates along the vehicle width direction in the LT radiator 14. Then, the cooling water flows out from the refrigerant outlet 14C at the lower part on the other end side in the vehicle width direction.

[0022] As shown in FIG. 1, for example, a transmission axle oil cooler 18 and a power control unit 20, which are examples of cooling targets, are connected to the cooling circuit 16, and cooling water circulates through each of them, having the function of cooling each of them. Note that the cooling targets of the cooling circuit 16 are not limited to the transmission axle oil cooler 18 and the power control unit 20, and other cooling targets may be applied.

[0023] The cooling circuit 16 includes an outflow part 16C connected to the refrigerant outlet 14C of the LT radiator 14, a first connection part 16A connected to the refrigerant inlet 14A at the upper part of the LT radiator 14, a second connection part 16B connected to the refrigerant inlet 14B at the central part of the LT radiator 14, and a switching part 22 for switching the flow of the refrigerant to the first connection part 16A and the second connection part 16B.

[0024] The switching part 22 includes a valve driven by an actuator or the like, and exclusively switches between the first connection part 16A and the second connection part 16B. Further, the switching part 22 is connected to the control part 24, and the switching of the switching part 22 is controlled by the control of the control part 24.

[0025] The control unit 24 is connected to the aforementioned switching unit 22 and air conditioning unit 26, and has the function of controlling the air conditioning unit 26 inside the vehicle, and controls the switching unit 22 based on the operating status of the air conditioning unit 26. For example, the control unit 24 controls the switching unit 22 according to the air conditioning settings, outside temperature, etc.

[0026] The air conditioning system 26 provides heating and cooling to the vehicle interior. For example, the air conditioning system 26 uses a refrigerant circulating in the HT radiator 12 to provide air conditioning (heating) to the vehicle interior. In addition to heating using the coolant flowing through the HT radiator 12 as a heat source, heating may also include heating using a heat pump. On the other hand, cooling is provided to the vehicle interior using a well-known refrigerant cycle including a compressor, condenser, evaporator, expansion valve, etc.

[0027] Here, we will explain the switching of the switching unit 22. Figure 3 is a schematic diagram showing the switching state of the switching unit 22 in winter, and Figure 4 is a schematic diagram showing the switching state of the switching unit 22 in summer.

[0028] During winter heating operation, as shown in Figure 3, the switching unit 22 is switched so that coolant flows into the LT radiator 14 from the first connection part 16A and not from the second connection part 16B.

[0029] By switching the switching unit 22 in this way, in winter, the entire surface of the LT radiator 14 is used to absorb heat and utilize it for heating performance. In other words, the heat absorbed from the transaxle oil cooler 18 and power control unit 20, which are to be cooled, is transferred from the LT radiator 14 to the adjacent HT radiator 12, and is utilized for the heating performance of the heater connected to the HT radiator 12.

[0030] On the other hand, when not operating in heating mode during the summer, the switching unit 22 is switched so that coolant flows from the second connection part 16B to the LT radiator 14, as shown in Figure 4, and not from the first connection part 16A.

[0031] Except during heating operation in the summer, the upper rear of the HT radiator 12 is hotter than the lower part (for example, about 80 degrees Celsius), while the lower part is cooler (for example, about 60 degrees Celsius). Since most of the objects to be cooled by the LT radiator 14 need to be cooled to about 65 degrees Celsius, the upper part of the LT radiator 14 receives heat from the exhaust of the HT radiator 12. On the other hand, the lower part of the LT radiator 14 dissipates heat. Therefore, by switching the switching unit 22 in this way, in the summer, the cooling performance is improved by using the cooler part of the adjacent HT radiator 12 to cool the LT radiator 14.

[0032] Next, we will describe the specific processing performed by the control unit 24 of the vehicle thermal management device 10 according to this embodiment, which is configured as described above. Figure 5 is a flowchart showing an example of the processing flow performed by the control unit 24 of the vehicle thermal management device 10 according to this embodiment. Note that the processing in Figure 5 starts, for example, when the operation of the air conditioner is instructed to start.

[0033] In step 100, the control unit 24 determines whether or not it is in heating operation. This determination is made based on the operating status of the air conditioning unit 26. For example, it may be determined based on the air conditioning settings or the outside temperature. Alternatively, it may be determined based on whether or not it is in heat pump operation. If the determination is negative, the system proceeds to step 102; if it is positive, the system proceeds to step 104.

[0034] In step 102, the control unit 24 switches the switching unit 22 to the second connection unit 16B and proceeds to step 106. That is, in cases other than heating operation, such as in summer, as shown in Figure 6, the upper rear part of the HT radiator 12 is hotter than the lower part, and the lower part is colder. Therefore, the switching unit 22 is switched so that cooling water flows into the LT radiator 14 from the refrigerant inlet 14B of the second connection unit 16B and not from the refrigerant inlet 14A of the first connection unit 16A. This allows the LT radiator 14 to be cooled using the lower temperature part of the adjacent HT radiator 12, thereby improving cooling performance.

[0035] On the other hand, in step 104, the control unit 24 switches the switching unit 22 to the first connection unit 16A and proceeds to step 106. That is, in winter, as shown in Figure 7, in order to use the entire surface of the LT radiator 14 to absorb heat and utilize it for heating performance, the switching unit 22 is switched so that cooling water flows into the LT radiator 14 from the refrigerant inlet 14A of the first connection unit 16A and not from the refrigerant inlet 14B of the second connection unit 16B. As a result, the heat absorbed by the LT radiator 14 from the transaxle oil cooler 18 and power control unit 20, which are being cooled, is transferred to the adjacent HT radiator 12, and can be used for the heating performance of the heater connected to the HT radiator 12.

[0036] In step 106, the control unit 24 determines whether or not to stop the air conditioning. This determination is, for example, whether or not an instruction has been given to stop the air conditioning operation. If the determination is negative, the process returns to step 100 and the above process is repeated until the determination is positive, at which point the series of processes ends.

[0037] Thus, in the vehicle thermal management device 10 according to this embodiment, the control unit 24 controls the switching unit 22 based on the operating status of the air conditioning unit 26, thereby maximizing the use of the LT radiator 14 and improving the heat exchange efficiency of the LT radiator 14.

[0038] In the above embodiment, the HT radiator 12 and LT radiator 14 are of the cross-flow type, but a down-flow type radiator may also be used. In this case, for example, in addition to the upper and lower tanks of the down-flow type radiator, a center tank is provided in the central part. Then, a refrigerant inlet 14A is provided in the upper tank and connected to the first connection part 16A, a refrigerant inlet 14B is provided in the center tank and connected to the second connection part 16B, and a refrigerant outlet is provided in the lower tank and connected to the outlet part 16C, thereby achieving the same effects as in the above embodiment.

[0039] Furthermore, the processing performed by the control unit 24 in each of the above embodiments may be software processing performed by executing a program, or hardware processing such as a GPU (Graphics Processing Unit), ASIC (Application Specific Integrated Circuit), and FPGA (Field-Programmable Gate Array). Alternatively, it may be processing that combines both software and hardware. In the case of software processing, the program may be stored in various storage media and distributed.

[0040] Furthermore, the present invention is not limited to the above, and it is of course possible to implement it in various modified forms without departing from its spirit. [Explanation of symbols]

[0041] 10. Vehicle thermal management system 12 HT Radiator (First Heat Exchanger) 14 LT Radiator (Second Heat Exchanger) 14A, 14B Refrigerant Inlet 14C Refrigerant outlet 16 Cooling circuit 16A First connection section 16B Second connection section 16C Outlet 22 Switching section 24 Control Unit 26 Air conditioner

Claims

1. The first heat exchanger is located at the front of the vehicle, A second heat exchanger is positioned adjacent to the first heat exchanger on the rear side of the vehicle, An air conditioning system that uses a refrigerant circulating within the first heat exchanger to air condition the interior of a vehicle, A cooling circuit connected to the second heat exchanger through which refrigerant flows includes an outlet connected to the refrigerant outlet of the second heat exchanger, a first connection connected to the refrigerant inlet located at the top of the second heat exchanger, a second connection connected to the refrigerant inlet located in the center of the second heat exchanger, and a switching unit that switches the flow of refrigerant to the first connection and the second connection based on the operating status of the air conditioning system. A vehicle thermal management system equipped with the following features.

2. The vehicle thermal management device according to claim 1, further comprising a control unit that controls the switching unit based on the operating status of the air conditioning device.

3. The vehicle thermal management device according to claim 2, wherein the control unit controls the switching unit so that refrigerant flows from the first connection unit to the second heat exchanger when the air conditioning device is in heating operation.

4. The vehicle thermal management device according to claim 2, wherein the control unit controls the switching unit so that refrigerant flows from the second connection unit to the second heat exchanger when the air conditioning device is not operating in heating mode.

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