Battery cooling device

Abstract

To secure an insulation performance even in the case where water is mixed into an insulation oil for cooling a battery.SOLUTION: A battery cooling device comprising a plurality of coolers for cooling a battery by an insulation oil, comprises: a communication pipe that connects the plurality of the cooling devices to each other, and through which the insulation oil flows; a water level sensor that is provided in a vertical part extending in a vertical direction of the communication pipe, and detects a water level of the vertical part; a shut-down valve that is provided in the communication pipe; and a control device that controls the shut-down valve. The control device closes the shut-down valve when the water level sensor detects a water level rise equal to or greater than a predetermined value.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a battery cooling device. [Background technology]

[0002] Patent document 1 discloses that in a structure in which insulating oil is stored around a battery cell and the insulating oil can enter the battery cell container from the top of the container to equalize the pressure inside and outside the battery cell, a sensor is used to detect the interface between the electrolyte and the insulating oil inside the container. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-016608 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the configuration described in Patent Document 1 assumes that the height of the interface between the electrolyte and the insulating oil in the container is monitored by a sensor, and does not assume that water or the like may be mixed into the insulating oil. In contrast, in a configuration in which the battery is cooled by insulating oil, there is a risk that the insulating properties may be reduced if water is mixed into the insulating oil.

[0005] The present invention has been made in consideration of the above circumstances, and aims to provide a battery cooling device that can maintain insulation even if water is mixed into the insulating oil used to cool the battery. [Means for solving the problem]

[0006] The present invention is a battery cooling device having a plurality of coolers that cool batteries with insulating oil, comprising a communicating pipe that connects the plurality of coolers together and through which the insulating oil flows, a water level sensor provided in a vertical section extending vertically of the communicating pipe and detecting the water level in the vertical section, a shut valve provided in the communicating pipe, and a control device that controls the shut valve, wherein the control device closes the shut valve when the water level sensor detects a water level rise above a predetermined value.

[0007] According to this configuration, the presence of a water column can be detected by providing a water level sensor in the vertical section of the communication pipe. When a rise in the water level in the vertical section is detected, the shut valve is closed, so insulation can be maintained even if water gets into the insulating oil used to cool the battery.

[0008] The shut valve may be made of an insulating material made of resin.

[0009] According to this configuration, the conductive path through the communication pipe can be cut off by closing the insulating valve. Effect of the Invention

[0010] In the present invention, the presence of a water column can be detected by providing a water level sensor in the vertical section of the communication pipe. When a rise in the water level in the vertical section is detected, the shut valve is closed, so that insulation can be maintained even if water gets mixed into the insulating oil used to cool the battery. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram illustrating a battery cooling device according to an embodiment. [Diagram 2] FIG. 2 is a diagram showing a circulation circuit of insulating oil. [Diagram 3] FIG. 3 is a block diagram for explaining the control device. [Figure 4]FIG. 4 is a flow chart showing the opening and closing control flow. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, a battery cooling device according to an embodiment of the present invention will be specifically described with reference to the drawings. Note that the present invention is not limited to the embodiment described below.

[0013] FIG 1 is a schematic diagram of a battery cooling device in an embodiment. The battery cooling device 1 cools a battery module 3 in which multiple battery cells 2 are stacked. The battery cooling device 1 includes multiple coolers 4 that cool the batteries with an insulating refrigerant. The battery cooling device 1 is mounted on a vehicle, and the battery to be cooled supplies power to the vehicle's driving motor. The battery represents the battery cell 2 as well as the battery module 3.

[0014] The battery cells 2 are formed in a structure in which the cells pass current directly in the stacking direction of the electrode planes of bipolar electrodes, etc. The battery module 3 has a stacked structure in which multiple battery cells 2 are stacked, and is configured so that the stacking direction of the battery cells 2 and the direction in which the current flows are the same.

[0015] In the battery cooling device 1, in order to efficiently cool the planar electrodes of the battery cells 2, a flat plate-shaped cooler 4 is inserted between the planar electrodes, and an insulating refrigerant is caused to flow inside the cooler 4. The cooler 4 is present inside the planar electrodes of the battery module 3, and is therefore in the current path. Therefore, the current voltage is also applied to the refrigerant inside the cooler 4. The insulating refrigerant that cools the battery cells 2 is insulating oil.

[0016] In addition, in the battery cooling device 1, when water or the like gets mixed into the insulating oil, a water lump may be formed inside the insulating oil pipe 10 through which the insulating oil flows. In this case, when the water lump straddles the two electrodes of the battery module 3, the insulation is impaired and a current is generated. In other words, when the insulating oil and water are stirred and turbid inside the insulating oil pipe 10, tiny water particles are suspended in the insulating oil. In this turbid state, no water lump is formed inside the insulating oil pipe 10, and insulation is ensured, i.e., the insulating oil is insulated, so no current is generated.

[0017] Because water has a higher specific gravity than oil, when the flow of insulating oil is stopped during vehicle soaking, the cloudy water particles begin to gather under the insulating oil piping 10 (below the refrigerant passage) due to gravity, forming a water mass. In the battery cooling device 1, water level sensors 15, 16 are arranged in the refrigerant passage of the insulating oil piping 10 where the liquid level of the water mass is likely to occur, and are configured to detect the intrusion of water. The battery cooling device 1 has a structure in which the water level sensors 15, 16 are provided in the communicating pipes 13, 14 connecting the two coolers 5, 6 at locations with a vertical component.

[0018] Specifically, the battery cooling device 1 includes a cooler 4, an insulating oil pipe 10, water level sensors 15 and 16, shut valves 17 and 18, and a control device 30 (shown in FIG. 3).

[0019] The cooler 4 is configured to include at least two coolers. As shown in Fig. 1, the cooler 4 has a first cooler 5 arranged on one side and a second cooler 6 arranged on the other side in the stacking direction of the battery modules 3. The stacking direction of the battery modules 3 is the same as the vertical direction of the vehicle.

[0020] The first cooler 5 is an upper cooler disposed above the second cooler 6 in the vertical direction of the vehicle. The insulating oil flowing inside the first cooler 5 is applied with the energizing current of the battery module 3. For example, the first cooler 5 functions as a positive electrode side current collector of the battery module 3.

[0021] The second cooler 6 is a lower cooler disposed below the first cooler 5 in the vertical direction of the vehicle. The insulating oil flowing inside the second cooler 6 is applied with the energizing current of the battery module 3. For example, the second cooler 6 functions as a negative electrode side current collector of the battery module 3.

[0022] The insulating oil pipe 10 is a refrigerant passage through which insulating oil flows. The insulating oil pipe 10 is connected to the cooler 4. The insulating oil pipe 10 has a supply pipe 11, an outflow pipe 12, and communication pipes 13 and 14.

[0023] The supply pipe 11 is a refrigerant passage formed on the inlet side of the cooler 4. Insulating oil is supplied from the supply pipe 11 to the cooler 4. The downstream side of the supply pipe 11 is connected to the communication pipe 13.

[0024] The communication pipe 13 is a first communication pipe formed between the supply pipe 11 and the inlet of the cooler 4, and is connected to the inlets of the multiple coolers 4. The communication pipe 13 has a vertical portion 13a, a first connection portion 13b, and a second connection portion 13c.

[0025] The vertical portion 13a is a portion of the communication pipe 13 that extends in the vertical direction. That is, the vertical portion 13a extends linearly along the stacking direction of the battery modules 3 and the vertical direction of the vehicle. The vertical portion 13a communicates with the supply pipe 11 at a middle position in the vertical direction. The vertical portion 13a also communicates with the first connection portion 13b at an upper end position in the vertical direction and communicates with the second connection portion 13c at a lower end position in the vertical direction.

[0026] The first connection portion 13b is a portion that is connected to the inlet of the first cooler 5 and extends horizontally. The second connection portion 13c is a portion that is connected to the inlet of the second cooler 6 and extends horizontally. In the vertical direction of the vehicle, the first connection portion 13b is disposed higher than the second connection portion 13c.

[0027] The insulating oil supplied from the supply pipe 11 to the communication pipe 13 is supplied through the vertical portion 13a from the first connection portion 13b on the upper side to the first cooler 5, and from the second connection portion 13c on the lower side to the second cooler 6. In the inlet side communication pipe 13, the insulating oil supplied to the cooler 4 branches into the first cooler 5 side and the second cooler 6 side.

[0028] The outflow pipe 12 is a refrigerant passage formed on the outlet side of the cooler 4. The insulating oil that has cooled the cooler 4 flows from the outflow pipe 12. The upstream side of the outflow pipe 12 is connected to a communication pipe 14.

[0029] The communication pipe 14 is a second communication pipe formed between the outlet of the cooler 4 and the outflow pipe 12, and is connected to the outlets of the multiple coolers 4. The communication pipe 14 has a vertical portion 14a, a first connection portion 14b, and a second connection portion 14c.

[0030] The vertical portion 14a is a portion of the communication pipe 14 that extends in the vertical direction. That is, the vertical portion 14a extends linearly along the stacking direction of the battery modules 3 and the vertical direction of the vehicle. The vertical portion 14a communicates with the outflow pipe 12 at a middle position in the vertical direction. The vertical portion 14a also communicates with the first connection portion 14b at an upper end position in the vertical direction and communicates with the second connection portion 14c at a lower end position in the vertical direction.

[0031] The first connection portion 14b is a portion that is connected to the outlet of the first cooler 5 and extends horizontally. The second connection portion 14c is a portion that is connected to the outlet of the second cooler 6 and extends horizontally. In the vertical direction of the vehicle, the first connection portion 14b is disposed higher than the second connection portion 14c.

[0032] The insulating oil supplied from the first cooler 5 on the upper side to the first connection portion 14b is supplied to the outlet pipe 12 via the vertical portion 14a. The insulating oil supplied from the second cooler 6 on the lower side to the second connection portion 14c is supplied to the outlet pipe 12 via the vertical portion 14a. In the communication pipe 14 on the outlet side, the insulating oil that has cooled the first cooler 5 and the insulating oil that has cooled the second cooler 6 join together.

[0033] The water level sensor 15 is a first water level sensor provided in the vertical section 13a of the inlet side communication pipe 13, and detects the water level in the vertical section 13a. The water level sensor 15 is disposed at a position closer to the second connection section 13c than to the first connection section 13b in the up-down direction, that is, at a relatively lower side of the vertical section 13a.

[0034] The water level sensor 16 is a second water level sensor provided in the vertical section 14a of the outlet side communication pipe 14, and detects the water level in the vertical section 14a. The water level sensor 16 is disposed at a position closer to the second connection section 14c than to the first connection section 14b in the up-down direction, that is, at a relatively lower side of the vertical section 14a.

[0035] The shutoff valve 17 is a first shutoff valve provided in the inlet side of the communicating pipe 13, and selectively closes the communicating pipe 13. The shutoff valve 17 is made of an insulating material such as resin, and is configured so that the parts that come into contact with the insulating oil do not contain metal. In the example shown in Fig. 1, the shutoff valve 17 is provided in the vertical part 13a of the communicating pipe 13, and the shutoff valve 17 is disposed above the water level sensor 15 in the up-down direction.

[0036] The shutoff valve 18 is a second shutoff valve provided in the communicating pipe 14 on the outlet side, and selectively closes the communicating pipe 14. The shutoff valve 18 is made of an insulating material such as resin, and is configured so that the parts that come into contact with the insulating oil do not contain metal. In the example shown in Fig. 1, the shutoff valve 18 is provided in the vertical part 14a of the communicating pipe 14, and the shutoff valve 18 is disposed above the water level sensor 16 in the up-down direction.

[0037] Moreover, the battery cooling device 1 is configured to circulate insulating oil. As shown in Fig. 2, the insulating oil circulates in a circulation circuit 20. The circulation circuit 20 functions as a circuit for managing the heat of the battery module 3. The circulation circuit 20 includes a heat exchanger 21, a reservoir tank 22, and an oil pump 23.

[0038] The heat exchanger 21 exchanges heat between the refrigerant in the separate system and the insulating oil. For example, the heat exchanger 21 is configured by a chiller. The heat exchanger 21 functions to transfer heat of the insulating oil in the circulation circuit 20 to the refrigerant in the separate system to cool the insulating oil. The reservoir tank 22 stores the insulating oil. The oil pump 23 pumps the insulating oil so that the insulating oil circulates within the circulation circuit 20.

[0039] The oil pump 23 discharges insulating oil and the insulating oil is pumped into the insulating oil piping 10, whereby the insulating oil is supplied from the supply piping 11 to the cooler 4 of the battery module 3. After cooling the battery module 3, the insulating oil is supplied to the heat exchanger 21 via the outflow piping 12. The insulating oil cooled in the heat exchanger 21 is stored in the reservoir tank 22. The oil pump 23 draws in the insulating oil from an inlet on the reservoir tank 22 side and discharges it from an outlet on the cooler 4 side.

[0040] When this circulation circuit 20 is mounted on a vehicle, in the vertical direction of the vehicle, the battery module 3 is disposed relatively lower than the heat exchanger 21, the reservoir tank 22, and the oil pump 23. Therefore, during a vehicle soak, water mixed in the insulating oil present in the insulating oil pipe 10 between the oil pump 23 and the battery module 3 collects in the supply pipe 11 located on the lower side. Similarly, water mixed in the insulating oil present in the insulating oil pipe 10 between the heat exchanger 21 and the battery module 3 collects in the outflow pipe 12 located on the lower side.

[0041] Therefore, as shown in Figure 1, a water level sensor 15 is provided in the vertical section 13a on the inlet side that communicates with the supply pipe 11, and the water level is detected by the water level sensor 15 in the vertical section 13a, and a water level sensor 16 is provided in the vertical section 14a on the outlet side that communicates with the outlet pipe 12, and the water level is detected by the water level sensor 16 in the vertical section 14a.

[0042] As shown in Fig. 3, the battery cooling device 1 includes a control device 30 that controls the open / closed states of the shut valves 17, 18. The control device 30 is an electronic control device that controls the battery cooling device 1. This electronic control device is configured to include a microcontroller equipped with a CPU, RAM, ROM, and an input / output interface. Signals from the water level sensors 15, 16 are input to the control device 30. Then, the control device 30 executes the opening / closing control of the shut valves 17, 18 based on the signals input from the water level sensors 15, 16.

[0043] 4 is a flow chart showing an opening / closing control flow. The control shown in FIG.

[0044] The control device 30 determines whether or not at least one of the inlet side water level sensor 15 and the outlet side water level sensor 16 has detected a rise in the water level (step S1). If it is determined that neither the inlet side water level sensor 15 nor the outlet side water level sensor 16 has detected a rise in the water level (step S1: No), this control routine ends.

[0045] When it is determined that at least one of the inlet side water level sensor 15 and the outlet side water level sensor 16 has detected a rise in the water level (step S1: Yes), the control device 30 closes the shutoff valves 17, 18 in the communicating pipes 13, 14 (step S2). In step S2, both the inlet side and the outlet side shutoff valves 17, 18 may be closed, or only the side where the rise in the water level has been detected may be closed. In other words, at least the shutoff valve arranged on the inlet side or the outlet side where the rise in the water level has been detected is closed.

[0046] As described above, according to the embodiment, when a rise in water level is detected in the vertical sections 13a, 14a of the communicating pipes 13, 14, the shut valves 17, 18 close, thereby preventing a water column caused by water mixed in the insulating oil from forming across the two electrodes.

[0047] It should be noted that the shutoff valve 17 does not have to be disposed above the water level sensor 15. The shutoff valve 17 only needs to be provided in the communicating pipe 13, and does not necessarily have to be provided in the vertical portion 13a. For example, the shutoff valve 17 is provided in the second connecting portion 13c. Similarly, the shutoff valve 18 does not have to be disposed above the water level sensor 16. The shutoff valve 18 only needs to be provided in the communicating pipe 14, and does not necessarily have to be provided in the vertical portion 14a. For example, the shutoff valve 18 is provided in the second connecting portion 14c.

[0048] The number of coolers 4 is not limited to two, and may be three or more. When the number of coolers 4 is three or more, one shut valve is provided for each insulating oil pipe connecting two coolers adjacent in the vertical direction. For example, when the number of coolers 4 is three, the coolers 4 are arranged in three places, namely, the top, middle, and bottom, so that the two coolers adjacent in the vertical direction are a combination of the upper cooler 4 and the middle cooler 4, and a combination of the middle cooler 4 and the lower cooler 4. Then, one shut valve is provided in the communication pipe connecting the upper cooler 4 and the middle cooler 4, and one shut valve is provided in the communication pipe connecting the middle cooler 4 and the lower cooler 4. Thereby, by closing the two shut valves as necessary, it is possible to prevent a conductive path from being formed across two electrodes.

[0049] In addition, the cooler 4 also functions as a current collector plate in the above-described embodiment, but the present invention is not limited to this. The cooler 4 may be disposed between the positive and negative current collector plates of the battery module 3.

[0050] Furthermore, there is no limit to the number of battery modules 3 to be cooled by the battery cooling device 1. In other words, the battery cooling device 1 can be used for a battery pack having a structure in which multiple battery modules 3 are stacked in a stacking direction. [Explanation of symbols]

[0051] 1 Battery cooling device 2 Battery Cells 3 Battery Module 4 Cooler 5 1st cooler 6 Second cooler 10. Insulating oil piping 11 Supply piping 12 Outlet pipe 13 Communication piping 13a Vertical section 13b First connection part 13c Second connection part 14 Communication piping 14a Vertical section 14b First connection part 14c Second connection part 15,16 Water level sensor 17,18 Shut valve 20 Circulation circuit 21 Heat exchanger 22 Reservoir tank 23 Oil pump 30 Control device

Claims

1. A battery cooling device having a plurality of coolers that cool batteries using insulating oil, a communication pipe connecting the plurality of coolers with each other and through which the insulating oil flows; a water level sensor provided in a vertical portion of the communication pipe that extends in a vertical direction and detects a water level in the vertical portion; a shut valve provided in the communication pipe; A control device for controlling the shut valve; Equipped with The control device closes the shut valve when the water level sensor detects a water level rise of a predetermined value or more. A battery cooling device comprising:

2. The shut valve is made of an insulating material made of resin. The battery cooling device according to claim 1 .

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