Battery temperature regulation system

Abstract

This invention provides a battery temperature control system that can improve the performance of batteries installed in vehicles. [Solution] The battery temperature control system 10 comprises a refrigerant circuit 30 for circulating liquid refrigerant 40, and a battery pack 20 having a plurality of battery cells 22 and a heat exchange unit 25. The heat exchange unit comprises a refrigerant flow path 32 through which the refrigerant flows, and a case 26 that houses the refrigerant flow path and has a first wall portion 26a on which the plurality of battery cells are installed, and a second wall portion 26b capable of dissipating heat from the refrigerant. The refrigerant flow path 32 has a fixed wall portion 32a in close contact with the first wall portion, and a movable wall portion 32b facing the fixed wall and capable of approaching and separating from the second wall portion. The movable wall portion is configured to be displaceable between a contact state in contact with the second wall portion and a separated state separated from the second wall portion by the pressure adjustment means of the refrigerant circuit.

Description

Technical Field

[0001] The present invention relates to a battery temperature adjustment system, and more particularly to a battery temperature adjustment system provided with a refrigerant circuit in which a liquid refrigerant circulates.

Background Art

[0002] In electric vehicles such as electric cars and hybrid cars, a battery serving as a drive source of the vehicle is mounted. Since the battery may cause a decrease in performance and a decrease in life if the temperature rises too much, an electric vehicle is equipped with a refrigerant circuit for cooling the battery. The refrigerant circuit is a circuit in which a refrigerant such as cooling water circulates, and includes a heat exchanger such as a radiator for cooling the refrigerant. In the refrigerant circuit, a part of the refrigerant flow path through which the refrigerant flows passes through a battery pack in which the battery is housed, and the battery is cooled by the refrigerant flowing through this refrigerant flow path.

[0003] For example, Patent Document 1 describes a battery temperature adjustment device including a refrigerant circuit in which a refrigerant circulates and a battery pack in which a battery having a plurality of battery cells is housed. The battery pack has a heat exchange part that performs heat exchange between the battery and the refrigerant circulating in the refrigerant circuit, and the heat exchange part has a cooling plate capable of releasing the heat of the refrigerant to the outside of the battery pack. The refrigerant flow path through which the refrigerant flows is fixed to the cooling plate in a state of being in contact with the cooling plate. In this battery temperature adjustment device, when the temperature of the battery becomes high, the heat absorbed by the refrigerant from the battery can be released to the outside of the battery pack through the cooling plate.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] To improve battery performance, it is necessary to cool the battery, which becomes hot while the vehicle is running, while simultaneously warming the battery, which is cold when the vehicle starts up, to bring the battery temperature within an appropriate range.

[0006] In the battery temperature control device described in Patent Document 1, a refrigerant is heated by the heat of a motor and sent to the battery pack, thereby warming the battery which is in a low-temperature state. However, since the heat from the refrigerant is released to the outside of the battery pack via a cooling plate, the battery is not being warmed efficiently.

[0007] This invention has been made in view of the above problems, and aims to provide a battery temperature control system that can improve the performance of a battery mounted on a vehicle. [Means for solving the problem]

[0008] To achieve the above objective, one embodiment of the present invention provides a battery temperature control system for adjusting the temperature of a battery mounted on a vehicle, A refrigerant circuit that circulates liquid refrigerant, The battery pack comprises a plurality of battery cells constituting the battery, and a heat exchange unit that performs heat exchange between the battery and the refrigerant, The heat exchange unit comprises a refrigerant flow path through which the refrigerant flows, a case having a first wall portion that houses the refrigerant flow path and in which the plurality of battery cells are installed, and a second wall portion that is positioned opposite the first wall portion and capable of dissipating heat from the refrigerant, The refrigerant circuit includes pressure adjustment means that adjusts the pressure in the refrigerant flow path of the heat exchange section based on the vehicle's running conditions and / or the battery temperature. The refrigerant flow path of the heat exchange section has a fixed wall portion that is in close contact with the first wall portion, and a movable wall portion that is opposite the fixed wall portion and can move closer to and further away from the second wall portion. The movable wall portion is configured to be displaceable between a contact state in which it is in contact with the second wall portion and a separated state in which it is separated from the second wall portion, by adjusting the pressure of the refrigerant flow path by the pressure adjustment means. [Effects of the Invention]

[0009] The battery temperature control system according to the present invention can improve the performance of a battery installed in a vehicle. [Brief explanation of the drawing]

[0010] [Figure 1] This is an explanatory diagram of a battery temperature control system, which is one embodiment of the present invention. [Figure 2] This is a block diagram showing the configuration of the control mechanism for the battery temperature control system. [Figure 3] This is an explanatory diagram of a vehicle equipped with a battery temperature control system. [Figure 4A] This is a schematic side view of a battery pack, showing the contact state of the movable wall portion of the deformable refrigerant flow path. [Figure 4B] Figure 4A is a right side view of the battery pack. [Figure 5A] This is a schematic side view of a battery pack, showing the separated state of the movable walls of the deformable refrigerant flow path. [Figure 5B] Figure 5A is a right side view of the battery pack. [Figure 6] This is a magnified perspective view of a portion of the refrigerant flow path housing case. [Figure 7A] This is a perspective view showing an example of a deformed refrigerant flow path. [Figure 7B] This is a perspective view showing another example of a deformed refrigerant flow path. [Figure 8A] This is an explanatory diagram showing an example of the cross-sectional shape of a deformed refrigerant flow path. [Figure 8B] This is an explanatory diagram showing another example of the cross-sectional shape of a deformed refrigerant flow path. [Figure 8C] This is an explanatory diagram showing yet another example of the cross-sectional shape of a deformed refrigerant flow path. [Figure 9] It is a diagram for explaining the operation of a battery temperature adjustment system. [Figure 10] It is a diagram for explaining the operation of a battery temperature adjustment system [Figure 11] It is a diagram for explaining the operation of a battery temperature adjustment system

Embodiments for Carrying out the Invention

[0011] FIG. 1 is an explanatory diagram of a battery temperature adjustment system 10 (hereinafter, also simply referred to as "temperature adjustment system 10") according to an embodiment of the present invention. FIG. 2 is a block diagram showing the configuration of the control mechanism of the temperature adjustment system 10. FIG. 3 is an explanatory diagram of a vehicle 1 equipped with the temperature adjustment system 10. The temperature adjustment system 10 is applied to an electric vehicle such as an electric vehicle or a hybrid vehicle in which a battery 21 is mounted as a drive source of the vehicle 1, and adjusts the temperature of the battery 21 mounted on the vehicle 1. As shown in FIG. 3, in the vehicle 1 of the present embodiment, a battery pack 20 in which the battery 21 is housed is mounted below the vehicle body 2. In FIG. 3, the left side is the front side of the vehicle 1, and the right side is the rear side of the vehicle 1.

[0012] As shown in FIG. 1, the temperature adjustment system 10 includes a battery pack 20 in which the battery 21 is housed, and a refrigerant circuit 30 that circulates a liquid refrigerant 40. The refrigerant circuit 30 includes a refrigerant flow path 31 through which the refrigerant 40 flows. A part of the refrigerant flow path 31 passes through the battery pack 20, and the refrigerant flow path 31 passing through the battery pack 20 constitutes a heat exchange part 25 that performs heat exchange between the refrigerant 40 and the battery 21.

[0013] As shown in Figures 4A and 4B, the battery pack 20 comprises a plurality of battery cells 22 constituting a battery 21, a battery housing case 24 that houses the battery 21, and a heat exchange unit 25 that performs heat exchange between the battery 21 and the refrigerant 40. In the illustrated example, a total of eight battery cells 22 are shown, with four battery cells 22 arranged in two rows, but the number and arrangement of the battery cells 22 are not limited to this. The battery cells 22 can be, for example, rechargeable lithium-ion batteries. The battery 21 can be configured to supply power to a drive motor M mounted on the vehicle 1 and to store the power generated by the motor M.

[0014] The battery housing case 24 is a case that houses a plurality of battery cells 22 inside, and in this embodiment, it is a housing formed in a flattened, substantially rectangular parallelepiped shape. The heat exchange section 25 is located above or below the plurality of battery cells 22 in the battery pack 20 mounted on the vehicle 1. In this embodiment, the heat exchange section 25, which is flatter than the battery housing case 24 and has a substantially rectangular parallelepiped shape, is located below the battery housing case 24 that houses the plurality of battery cells 22.

[0015] The heat exchange unit 25 is positioned on the refrigerant circuit 30 and constitutes a part of the refrigerant circuit 30. The heat exchange unit 25 is a refrigerant flow path 31 through which the refrigerant 40 of the refrigerant circuit 30 flows, and comprises a deformable refrigerant flow path 32 whose cross-sectional shape can be changed, and a case 26 that houses the deformable refrigerant flow path 32. The case 26 is a housing formed in a substantially rectangular parallelepiped shape and has a first wall portion 26a on which a plurality of battery cells 22 are installed, and a second wall portion 26b which is positioned opposite the first wall portion 26a at a predetermined distance. The first wall portion 26a and the second wall portion 26b can be made of a material with high thermal conductivity. In this embodiment, the first wall portion 26a forms the upper surface of the heat exchange unit 25, the second wall portion 26b forms the bottom surface of the heat exchange unit 25, and the outer surface of the first wall portion 26a forms the mounting surface for the battery cells 22. The second wall portion 26b is in contact with the atmosphere outside the battery pack 20 and constitutes a heat dissipation wall portion that can dissipate the heat of the refrigerant 40 to the outside of the battery pack 20.

[0016] As shown in Figures 4A, 4B, 5A, and 5B, the deformable refrigerant flow path 32 within the case 26 comprises a fixed wall portion 32a that is in close contact with the first wall portion 26a of the case 26, and a movable wall portion 32b that faces the fixed wall portion 32a. The movable wall portion 32b is configured to move closer to and further away from the fixed wall portion 32a within the case 26. When the pressure in the deformable refrigerant flow path 32 increases, it moves away from the fixed wall portion 32a, and when the pressure in the deformable refrigerant flow path 32 decreases, it moves closer to the fixed wall portion 32a. In Figures 4B and 5B, the arrows indicate heat transfer. As shown in Figures 4A and 4B, when the movable wall portion 32b is furthest away from the fixed wall portion 32a, it is in contact with the second wall portion 26b of the case 26. Furthermore, as shown in Figures 5A and 5B, when the movable wall portion 32b approaches the fixed wall portion 32a, it enters a separated state, separated from the second wall portion 26b of the case 26. In this way, the movable wall portion 32b is configured to be displaceable between a contact state and a separated state with respect to the second wall portion 26b of the case 26, and in the separated state, an air layer 29 is formed between the deformable refrigerant flow path 32 and the second wall portion 26b.

[0017] Figure 6 is a partially enlarged perspective view of case 26. Case 26 has air chambers 27 separated by partition walls 26d at the upstream and downstream ends of the deformed refrigerant flow path 32. Here, the upstream and downstream ends refer to the upstream and downstream ends in the flow direction of the refrigerant 40 in the refrigerant circuit 30, and in this embodiment, the upstream and downstream ends are the ends of the case 26 in the longitudinal direction. In this embodiment, case 26 is formed symmetrically with respect to the center in the longitudinal direction, and Figure 6 shows the end on the refrigerant inflow side.

[0018] As shown in Figures 5A and 6, the deformable refrigerant flow path 32 is housed inside a pair of partition walls 26d. A refrigerant inlet pipe 32c and a refrigerant outlet pipe 32d are attached to the upstream and downstream ends of the deformable refrigerant flow path 32. The refrigerant inlet pipe 32d and the refrigerant outlet pipe 32d penetrate an air chamber 27 partitioned by the side wall portion 26c of the case 26 and the partition wall 26d. Multiple ventilation holes 26e are formed in the partition wall 26d, allowing air to move between the housing space 28 in which the deformable refrigerant flow path 32 is housed and the air chamber 27. When the movable wall portion 32b of the deformable refrigerant flow path 32 approaches the second wall portion 26b of the case 26, air in the housing space 28 moves into the air chamber 27. This improves the airtightness between the second wall portion 26b and the movable wall portion 32b when the movable wall portion 32b is in contact with the second wall portion 26b. Furthermore, when separating the movable wall portion 32b from the second wall portion 26b, the air in the space portion 27 enters the containment space 28 through the ventilation hole 26e, thereby enabling the movable wall portion 32b to be quickly separated from the second wall portion 26b.

[0019] Next, the deformable refrigerant flow path 32 will be described. The deformable refrigerant flow path 32 can be made of a flexible material and can be structured to expand and contract in response to changes in pressure within the deformable refrigerant flow path 32. Figures 7A and 7B are perspective views showing examples of the deformable refrigerant flow path 32, respectively, with the contracted state of the deformable refrigerant flow path 32 shown by a solid line and the expanded state of the deformable refrigerant flow path 32 shown by a dashed line. In the example shown in Figure 7A, the movable wall portion 32b is made of an expandable and contractible material, and as the pressure in the deformable refrigerant flow path 32 increases, the movable wall portion 32b expands, increasing the cross-sectional area of ​​the flow path. In the example shown in Figure 7B, the upstream and downstream ends of the deformable refrigerant flow path 32 are folded, and as the pressure in the deformable refrigerant flow path 32 increases, the folded portion expands, resulting in a flow path that roughly follows the inner wall of the case 26.

[0020] Figures 8A, 8B, and 8C show examples of the cross-sectional shape of the deformable refrigerant flow path 32, respectively. The left side shows the contracted state of the deformable refrigerant flow path 32, and the right side shows the expanded state of the deformable refrigerant flow path 32. In the example shown in Figure 8A, the movable wall portion 32b of the deformable refrigerant flow path 32 is made of an expandable and contractible material, and in the contracted state, the cross-sectional shape is approximately semi-elliptical. In the expanded state, the movable wall portion 32b contacts the inner wall surface of the case 26, resulting in a roughly rectangular cross-sectional shape. In the example shown in Figure 8B, in the contracted state, the movable wall portion 32b has a semi-elliptical shape with the central part flattened. In the expanded state, the flattened portion expands, and the deformable refrigerant flow path 32 contacts the inner wall surface of the case 26, resulting in a roughly rectangular cross-sectional shape. In the example shown in Figure 8C, both ends of the deformable refrigerant flow path 32 are formed in a bellows shape. In the contracted state, the bellows portion of this deformable refrigerant flow path 32 is folded, and in the expanded state, the bellows portion is extended.

[0021] Next, the refrigerant circuit 30 will be described. As shown in Figure 1, the refrigerant circuit 30 includes a pump 37, a first flow control valve 33, a second flow control valve 34, a reservoir tank 38, a first heat exchanger 42, a second heat exchanger 46, a first switching valve 44, and a second switching valve 48. Furthermore, as shown in Figure 2, the refrigerant circuit 30 includes a control unit 50 that controls the driving of the first heat exchanger 42, the second heat exchanger 46, the first switching valve 44, and the second switching valve 48.

[0022] Pump 37 pumps the refrigerant flowing through the refrigerant passage 31, circulating the refrigerant 40 in the refrigerant circuit 30. Pump 37 is located downstream of the deformed refrigerant passage 32. The reservoir tank 38 is located downstream of pump 37 in the refrigerant circuit 30 and is a tank capable of storing the refrigerant 40 inside.

[0023] The first flow rate adjustment valve 33 is located upstream of the heat exchange section 25 of the battery pack 20 in the refrigerant circuit 30 and adjusts the flow rate of the refrigerant 40 flowing through the refrigerant passage 31. The second flow rate adjustment valve 34 is located downstream of the heat exchange section 25 and upstream of the pump 37 and adjusts the flow rate of the refrigerant 40 flowing through the refrigerant passage 31.

[0024] The first heat exchanger 42 and the second heat exchanger 46 are located in the refrigerant circuit 30 downstream of the reservoir tank 38 and upstream of the first flow control valve 33. The first heat exchanger 42 is a heat exchanger capable of heating the refrigerant 40 and is configured to exchange heat between the refrigerant 40 and the motor M, which is a heat source. In this embodiment, the first heat exchanger 42 is configured to allow the refrigerant 40 to indirectly exchange heat with the motor M by performing heat exchange between the refrigerant 40 and the oil supplied to the motor M. The second heat exchanger 46 is a heat exchanger capable of dissipating heat from the refrigerant 40. The second heat exchanger 46 can be, for example, a radiator capable of releasing the heat of the refrigerant 40 into the atmosphere.

[0025] The first switching valve 44 and the second switching valve 48 are located downstream of the reservoir tank 38 and upstream of the first flow control valve 33. The first and second switching valves 44 and 48 are valves that switch the flow path through which the refrigerant 40 circulates between a first flow path that passes only through the first heat exchanger 42 of the first and second heat exchangers 42 and 46, and a second flow path that passes only through the second heat exchanger 46.

[0026] In this embodiment, the refrigerant flow path 31 is branched upstream of the first heat exchanger 42 into a first branch flow path 41a that passes through the first heat exchanger 42 and a second branch flow path 41b that does not pass through the first heat exchanger 42, and the first and second branch flow paths 41a and 41b merge upstream of the first heat exchanger 42. The first switching valve 44 is installed at the junction of the first branch flow path 41a and the second branch flow path 41b, and the first switching valve 44 can be used to switch between the first branch flow path 41a and the second branch flow path 41b by closing one branch flow path and opening the other branch flow path. Furthermore, the refrigerant flow path 31 is branched upstream of the second heat exchanger 46 into a third branch flow path 45a that passes through the second heat exchanger 46 and a fourth branch flow path 45b that does not pass through the second heat exchanger 46. Upstream of the second heat exchanger 42, the third and fourth branch flow paths 45a and 45b merge. The second switching valve 48 is installed at the junction of the third branch flow path 45a and the fourth branch flow path 45b. The second switching valve 48 can be used to switch between the third branch flow path 45a and the fourth branch flow path 45b by closing one branch flow path and opening the other.

[0027] The control unit 50 is configured to include, for example, an information processing unit such as a CPU, a storage unit such as RAM or ROM, and an input / output interface. As shown in Figure 2, the control unit 50 is electrically connected to an internal sensor 52 that detects the driving state of the vehicle 1, a battery temperature sensor 54 that detects the temperature of the battery 21, and a refrigerant temperature sensor 56 that detects the temperature of the refrigerant 40 of the refrigerant circuit 30.

[0028] The internal sensor 52 is a detection device located inside the vehicle 1 that detects the driving state of the vehicle 1. The internal sensor 52 includes, for example, a vehicle speed sensor that detects the speed of the vehicle 1, an acceleration sensor that detects the acceleration of the vehicle 1, and a shift state detection sensor that detects the state of the shift lever. Based on the signals received from the internal sensor 52, the control unit 50 can determine whether the vehicle 1 is driving, whether the vehicle 1 is stopped and parked, and whether the vehicle 1 has started.

[0029] The battery temperature sensor 54 can be, for example, attached to the battery housing case 24 of the battery pack 20 and be a temperature sensor capable of directly or indirectly detecting the temperature of the battery 21. Based on the signal received from the battery temperature sensor 54, the control unit 50 can determine whether the temperature of the battery 21 is in a predetermined high-temperature state requiring cooling or in a predetermined low-temperature state requiring heating.

[0030] The refrigerant temperature sensor 56 can be, for example, positioned in the refrigerant circuit 30 near the downstream side of the heat exchange section 25 of the battery pack 20, and can be a detectable temperature sensor capable of directly or indirectly detecting the temperature of the refrigerant 40 passing through the heat exchange section 25. Based on signals received from the battery temperature sensor 54 and / or the refrigerant temperature sensor 56, the control unit 50 can determine whether the circuit through which the refrigerant 40 circulates is a first flow path that heats the refrigerant 40 with the first heat exchanger 44, or a second flow path that cools the refrigerant 40 with the second heat exchanger 46.

[0031] The control unit 50 is electrically connected to the first flow control valve 33, the second flow control valve 34, the first switching valve 44, and the second switching valve 48, and controls the operation of each valve 33, 34, 44, and 48 based on detection signals from each sensor 52, 54, and 56. Specifically, when heating the refrigerant 40 in the refrigerant circuit 30, the control unit 50 controls the first and second switching valves 44 and 48 so that the first branch flow path 41a and the fourth branch flow path 45b are selected, that is, the first flow path passes only through the first heat exchanger 42 of the first and second heat exchangers 42 and 46. On the other hand, when cooling the refrigerant 40 in the refrigerant circuit 30, the control unit 50 controls the first and second switching valves 44 and 48 so that the second branch flow path 41b and the third branch flow path 45a are selected, that is, the second flow path passes only through the second heat exchanger 46 of the first and second heat exchangers 42 and 46.

[0032] The control unit 50 can change the pressure in the deformable refrigerant flow path 32 located between the first flow control valve 33 and the second flow control valve 34 in the refrigerant circuit 30 by controlling the opening of these valves while the pump 37 is running. In the refrigerant circuit 30, the first flow control valve 33, the second flow control valve 34, the pump 37, the reservoir tank 38, and the control unit 50 constitute a pressure adjustment means that adjusts the pressure in the refrigerant flow path 31 of the heat exchange unit 25, i.e., the deformable refrigerant flow path 32, based on the driving state of the vehicle 1 and / or the temperature of the battery 21.

[0033] Next, the operation of the temperature control system 10 described above will be explained. First, the procedure for changing the deformable refrigerant flow path 32 from the expanded state shown in Figure 9 to the contracted state shown in Figure 10 will be explained. In the expanded state of the deformable refrigerant flow path 32 shown in Figure 9, the movable wall portion 32b of the deformable refrigerant flow path 32 is in close contact with the second wall portion 26b of the case 26, and the first flow control valve 33 and the second flow control valve 34 are fully open. First, the control unit 50 maintains the fully open state of the second flow control valve 34 and reduces the opening degree of the first flow control valve 33, slightly closing the first flow control valve 33. As a result, in the refrigerant circuit 30, the pressure in the refrigerant flow path 31 downstream of the first flow control valve 33 and upstream of the pump 37 decreases, and the pressure downstream of the pump 37 increases. This pressure change causes the pressure in the deformable refrigerant flow path 32 to decrease, causing the deformable refrigerant flow path 32 to contract so that its volume decreases, and the movable wall portion 32b of the deformable refrigerant flow path 32 to separate from the second wall portion 26b of the case 26. In addition, the pressure in the refrigerant flow path 31 in which the reservoir tank 38 is located increases, which increases the amount of refrigerant 40 in the reservoir tank 38.

[0034] Next, the procedure for changing the deformable refrigerant flow path 32 from the contracted state shown in Figure 10 to the expanded state shown in Figure 9 will be described. In the contracted state shown in Figure 10, the control unit 50 increases the opening of the first flow rate adjustment valve 33 to a fully open state, and decreases the opening of the second flow rate adjustment valve 34 to slightly close the second flow rate adjustment valve 34. As a result, in the refrigerant circuit 30, the pressure in the refrigerant flow path 31 downstream of the first flow rate adjustment valve 33 and upstream of the pump 37 increases, while the pressure downstream of the pump 37 decreases. Due to this pressure change, the pressure in the deformable refrigerant flow path 32 increases, causing the deformable refrigerant flow path 32 to expand so that its volume increases, and the movable wall portion 32b of the deformable refrigerant flow path 32 comes into close contact with the second wall portion 26b of the case 26. In addition, the amount of refrigerant 40 in the reservoir tank 38 decreases as the pressure in the refrigerant flow path 31 in which the reservoir tank 38 is located decreases.

[0035] Although the second flow rate adjustment valve 34 is not an essential component of the temperature control system 10, adjusting the flow rate with the second flow rate adjustment valve 34 can improve the responsiveness of the deformation operation of the deformable refrigerant flow path 32.

[0036] The temperature control system 10 described above controls the first and second flow rate adjustment valves 33 and 34 by the control unit 50 based on the driving state of the vehicle 1 as measured by the internal sensor 52 and / or the battery temperature as measured by the battery temperature sensor 54. As a result, the temperature control system 10 can control the state of the deformable refrigerant flow path 32 so that the movable wall portion 32b of the deformable refrigerant flow path 32 is in contact with or separated from the second wall portion 26b of the case 26.

[0037] For example, the temperature control system 10 adjusts the pressure in the deformable refrigerant flow path 32 so that the movable wall portion 32b of the deformable refrigerant flow path 32 is in close contact with the second wall portion 26b when the vehicle 1 is running and / or the battery 21 is in a predetermined high-temperature state. When the vehicle is running, the temperature of the battery 21 rises, so it is necessary to cool the battery 21. In this embodiment, the temperature control system 10 makes the deformable refrigerant flow path 32 into contact with the second wall portion 26b as shown in Figure 9, so that the heat of the refrigerant 40 flowing through the deformable refrigerant flow path 32 is released from the second wall portion 26b to the outside of the battery pack 20, thereby dissipating the heat of the refrigerant 40.

[0038] Furthermore, the temperature control system 10 adjusts the pressure in the deformable refrigerant flow path 32 so that the movable wall portion 32b of the deformable refrigerant flow path 32 is separated from the second wall portion 26b when the vehicle 1 is parked and / or the battery 21 is in a predetermined low temperature state. When the vehicle is parked, the temperature of the battery 21 gradually decreases. If the battery temperature is low when the vehicle is started, the battery performance cannot be fully utilized, so when parked, it is necessary to keep the battery 21 warm with the warmed refrigerant 40 to suppress the decrease in battery temperature. In this embodiment, the temperature control system 10 sets the deformable refrigerant flow path 32 to a separated state, slightly separated from the second wall portion 26b, as shown in Figure 11, when the vehicle 1 is parked. This forms an air layer 29, i.e., an insulating layer, between the movable wall portion 32b of the deformable refrigerant flow path 32 and the second wall portion 26b, thereby suppressing the release of heat from the refrigerant 40 to the outside from the second wall portion 26b. Furthermore, by increasing the volume of refrigerant 40 in the deformable refrigerant channel 32 for keeping the battery 21 warm compared to the state of the deformable refrigerant channel 32 shown in Figure 10, the performance of storing heat generated during vehicle operation can be improved. The state shown in Figure 11 is the expanded state of the deformable refrigerant channel 32 with an insulating layer, which has an insulating layer between it and the second wall portion 26b. This improves the heat storage performance of the refrigerant 40 compared to the contracted state of the deformable refrigerant channel 32 with an insulating layer shown in Figure 10. In addition, even when the battery 21 is in a predetermined low-temperature state, by providing an air layer 29 between the movable wall portion 32b and the second wall portion 26b of the deformable refrigerant channel 32, as shown in Figure 10 or Figure 11, the heat dissipation of the refrigerant 40 can be suppressed, thereby suppressing the temperature drop of the battery 21.

[0039] Next, the operation of the temperature control system 10 when starting a parked vehicle 1 will be described. When parked, as shown in Figure 11, the heat exchange section 25 of the battery pack 20 is in an expanded state of the deformable refrigerant flow path 32 with an insulating layer. When the battery 21 and refrigerant 40 are in a low-temperature state due to parking, and the internal sensor 52 detects that the vehicle 1 is starting, the control unit 50 switches the refrigerant circuit 30 to a first flow path that can heat the refrigerant 40 with the first heat exchanger 42. Also, when the vehicle 1 is detected to be starting, the control unit 50 controls the first and second flow rate adjustment valves 33 and 34 to reduce the pressure in the deformable refrigerant flow path 32, causing the deformable refrigerant flow path 32 to contract, as shown in Figure 10. This discharges the low-temperature refrigerant 40 in the deformable refrigerant flow path 32 to the outside of the heat exchange section 25, reducing the volume of the deformable refrigerant flow path 32. When starting the vehicle, it is preferable that the volume of the deformable refrigerant flow path 32 be kept to a minimum.

[0040] After the vehicle 1 is started, the refrigerant 40 is heated by the first heat exchanger 42, and when the temperature of the refrigerant 40 becomes higher than the temperature of the battery 21, the control unit 50 controls the first and second flow rate adjustment valves 33 and 34 to expand the deformable refrigerant flow path 32, as shown in Figure 11, and maintains the separation state between the movable wall portion 32b and the second wall portion 26b of the deformable refrigerant flow path 32. By expanding the deformable refrigerant flow path 32 in this way and increasing its volume, the effect of the surface area of ​​the deformable refrigerant flow path 32 is relatively reduced, and the loss of thermal energy due to heat dissipation can be reduced.

[0041] As described above, in the temperature control system 10 of this embodiment, when it is desired to cool the battery 21, the deformable refrigerant flow path 32 can be brought into close contact with the second wall portion 26b of the case 26, thereby promoting heat dissipation in the heat exchange section 25 on the side opposite the battery 21. Furthermore, when it is desired to keep the battery 21 warm or to raise the temperature of the battery 21 quickly, the temperature control system 10 can move the deformable refrigerant flow path 32 away from the second wall portion 26b of the case 26, thereby suppressing heat dissipation of the refrigerant 40. This makes it possible to extend the driving range of the battery 21, stabilize the output of the battery 21, shorten the charging time, and suppress the deterioration of the battery 21, thereby improving battery performance.

[0042] It should be noted that the present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention.

[0043] For example, the temperature control system according to the present invention may be configured to displace the movable wall portion 32b of the deformable refrigerant flow path 32 based on either the driving state of the vehicle 1 or the temperature of the battery 21. [Explanation of symbols]

[0044] 1 vehicle 10. Battery temperature regulation system 20 Battery Packs 21 batteries 22 battery cells 25 Heat exchange section 26 cases 26a First wall section 26b Second wall section 30 Refrigerant Circuit 31 Refrigerant flow path 32 Deformed refrigerant flow path 33. First flow control valve 34. Second flow control valve 37 Pumps 38 Reservoir Tank 42 First heat exchanger 44. First changeover valve 46. ​​Second heat exchanger 48. Second switching valve 50 Control Unit

Claims

1. In a battery temperature control system that adjusts the temperature of a battery installed in a vehicle, A refrigerant circuit that circulates liquid refrigerant, The battery pack comprises a plurality of battery cells constituting the battery, and a heat exchange unit that performs heat exchange between the battery and the refrigerant, The heat exchange unit comprises a refrigerant flow path through which the refrigerant flows, a case having a first wall portion that houses the refrigerant flow path and in which the plurality of battery cells are installed, and a second wall portion that is positioned opposite the first wall portion and capable of dissipating heat from the refrigerant, The refrigerant circuit includes pressure adjustment means that adjusts the pressure in the refrigerant flow path of the heat exchange section based on the vehicle's running conditions and / or the battery temperature. The refrigerant flow path of the heat exchange section has a fixed wall portion that is in close contact with the first wall portion, and a movable wall portion that is opposite the fixed wall portion and can move closer to and further away from the second wall portion. A battery temperature control system characterized in that the movable wall portion is configured to be displaceable between a contact state in which it is in contact with the second wall portion and a separated state in which it is separated from the second wall portion, by adjusting the pressure of the refrigerant flow path by the pressure adjustment means.

2. The battery temperature adjustment system according to claim 1, characterized in that the pressure adjustment means adjusts the pressure in the refrigerant flow path to increase and the movable wall portion to be in contact when the vehicle is running and / or the battery is in a predetermined high temperature state, and adjusts the pressure in the refrigerant flow path to decrease and the movable wall portion to be in the separated state when the vehicle is parked and / or the battery is in a predetermined low temperature state.

3. The pressure adjusting means is In the refrigerant circuit, a first flow control valve is located upstream of the heat exchange section, A pump located downstream of the heat exchange section, A reservoir tank is located downstream of the pump and is capable of storing the refrigerant, A control unit that controls the opening degree of the first flow control valve according to the driving state of the vehicle and / or the temperature of the battery, A battery temperature control system according to claim 1 or 2, characterized by comprising the following:

4. The pressure adjustment means includes a second flow rate adjustment valve located downstream of the heat exchange section and upstream of the pump. The battery temperature control system according to claim 3, characterized in that the control unit controls the opening degree of the second flow rate control valve according to the driving state of the vehicle and / or the temperature of the battery.

5. The refrigerant circuit comprises, downstream of the reservoir tank and upstream of the first flow control valve, a first heat exchanger for heating the refrigerant, a second heat exchanger for dissipating heat from the refrigerant, and a switching valve for switching the flow path of the refrigerant. The switching valve is capable of switching the flow path between a first flow path that passes only through the first heat exchanger and a second flow path that passes only through the second heat exchanger. The control unit, Based on the vehicle's running condition, the battery temperature, and the refrigerant temperature, the operation of the switching valve and the first flow rate adjustment valve is controlled. When the vehicle is started and the battery temperature and the refrigerant temperature are at a predetermined low temperature, the switching valve switches to the first flow path and the opening of the first flow rate adjustment valve is reduced to bring the movable wall closer to the fixed wall. The battery temperature control system according to claim 3, characterized in that, after the vehicle has been started and the temperature of the refrigerant has changed from the low temperature state to a non-low temperature state, the opening of the first flow control valve is increased while maintaining the separation state between the movable wall and the second wall, thereby separating the movable wall from the fixed wall.

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