Battery cooling device

Abstract

To provide a battery cooling device which includes cooling liquid comprised of insulation oil and can be suppressed in deterioration of cooling performance due to inmixing of water into the cooling liquid.SOLUTION: A battery cooling device of the present invention, is a battery cooling device comprising a first cooling liquid circulation circuit in which first cooling liquid for cooling a battery and comprised of insulation oil circulate. The first cooling liquid circulation circuit is comprised of: a first reserve tank temporarily accumulating the first cooling liquid; an inmixed water accumulation tank accumulating water inmixed into the first cooling liquid; an electrode device electrolyzing the water accumulated in the inmixed water accumulation tank; and gas-dedicated piping for guiding hydrogen gas and oxygen gas, generated by electrolyzing water by the electrode device to the first reserve tank separated from the first cooling liquid. In an upper portion of the first reserve tank, a first lid member sealing an open on an upper surface side of the first reserve tank is provided. The first lid member is comprised of resin material that penetrates the hydrogen gas and the oxygen gas.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Patent Document 1 discloses a technology in which, in a cooling system for an in-vehicle battery with insulating oil, the same insulating oil is used as a coolant to cool the PCU and transaxle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-029140 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, there is still room for improvement in measures against the deterioration of cooling performance caused by the inclusion of water in the cooling liquid made of insulating oil.

[0005] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide a battery cooling device that can suppress the deterioration of cooling performance due to water being mixed into a cooling liquid consisting of insulating oil. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, the battery cooling device of the present invention is a battery cooling device equipped with a first coolant circulation circuit that circulates a first coolant made of insulating oil that cools a battery, and the first coolant circulation circuit is composed of at least a first reserve tank that temporarily stores the first coolant, a mixed water collection tank that collects water mixed into the first coolant, an electrode device that electrolyzes the water accumulated in the mixed water collection tank, and a dedicated gas piping for guiding the hydrogen gas and the oxygen gas produced by electrolyzing the water by the electrode device to the first reserve tank separately from the first coolant, and a first cover member is provided on the upper part of the first reserve tank to cover an opening on the upper side of the first reserve tank, and the first cover member is composed of a resin material that is permeable to hydrogen gas and oxygen gas.

[0007] This allows the hydrogen gas and oxygen gas produced by electrolyzing water mixed into the first cooling liquid using the electrode device to be guided to the first reserve tank through a dedicated gas piping and released to the outside of the first reserve tank through the lid member, thereby suppressing a decrease in cooling performance due to water mixing into the first cooling liquid.

[0008] In the above, a second coolant circulation circuit may be provided that circulates a second coolant made of insulating oil that cools the battery, separate from the first coolant circulation circuit, and the second coolant circulation circuit may be configured to include at least a second reserve tank that temporarily stores the second coolant, and piping that guides water that has become mixed in the second coolant to the mixed water collection tank.

[0009] This makes it possible to suppress a decrease in cooling performance due to water mixing into the first and second coolants, while allowing the battery to be cooled by the second coolant circulation circuit even if the first coolant circulation circuit is in a failed state.

[0010] In the above, the first reserve tank may be provided with a pressure sensor that detects the pressure within the first reserve tank, and may be provided with a connecting pipe that connects a space in the second reserve tank above the highest possible position for the liquid level of the second cooling liquid with a space in the first reserve tank above the highest possible position for the liquid level of the first cooling liquid.

[0011] This allows the pressure sensor to be shared between the first coolant circulation circuit and the second coolant circulation circuit, thereby reducing the number of sensors to be installed. Effect of the Invention

[0012] The battery cooling device of the present invention can guide hydrogen gas and oxygen gas produced by electrolyzing water mixed into the coolant using an electrode device to a first reserve tank through a dedicated gas piping, and release the gas to the outside of the first reserve tank through the lid member, thereby achieving the effect of suppressing a decrease in cooling performance due to water being mixed into the coolant made of insulating oil. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a battery cooling device according to the first embodiment. [Diagram 2] FIG. 2 is a diagram showing a schematic configuration of a battery cooling device according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] (Embodiment 1) A first embodiment of a battery cooling device according to the present invention will be described below. Note that the present invention is not limited to this embodiment.

[0015] Fig. 1 is a diagram showing a schematic configuration of a battery cooling device 1 according to embodiment 1. The battery cooling device 1 according to embodiment 1 shown in Fig. 1 adjusts the battery temperature of assembled batteries 2A, 2B by cooling assembled batteries 2A, 2B mounted on a vehicle as objects to be cooled. Assumed vehicles on which the battery cooling device 1 is mounted include, for example, electric vehicles that can be driven by a motor powered by assembled batteries 2A, 2B, hybrid vehicles, and the like.

[0016] The assembled batteries 2A, 2B have multiple rectangular parallelepiped battery cells and battery temperature sensors 21A, 21B that detect the battery temperature, which is the temperature of the assembled batteries 2A, 2B (battery cells). The battery temperature sensors 21A, 21B may be provided for only one of the multiple battery cells, or may be provided for multiple battery cells, such as all the battery cells.

[0017] The battery cooling device 1 according to the first embodiment includes an electronic control device 3 and a coolant circulation circuit (first coolant circulation circuit) 100. The coolant circulation circuit 100 includes a reserve tank (first reserve tank) 101, a chiller 102, an oil pump 103, coolers 104A and 104B, a coolant pipe 105, a mixed water accumulation tank 106, an electrode device 107, and a dedicated gas pipe 108.

[0018] In the coolant circulation circuit 100, the reserve tank 101, the chiller 102, the oil pump 103, and the coolers 104A and 104B are connected in a ring shape by the coolant piping 105. The coolant piping 105 is composed of a first piping 105a connecting the reserve tank 101 and the chiller 102, a second piping 105b connecting the chiller 102 and the oil pump 103, a third piping 105c and a fourth piping 105d connecting the oil pump 103 and the coolers 104A and 104B, and a fifth piping 105e and a sixth piping 105f connecting the coolers 104A and 104B and the reserve tank 101. Insulating oil is used as the coolant 10 (first coolant) that circulates through the coolant circulation circuit 100 to cool the assembled batteries 2A and 2B.

[0019] The electronic control device 3 is a control device that performs overall control of the entire battery cooling device 1, and controls the oil pump 103, the electrode device 107, etc., based on the detection results of battery temperature sensors 21A, 21B provided in the assembled batteries 2A, 2B. The electronic control device 3 may also serve as an electronic control device that performs various controls related to the running of the vehicle in which the battery cooling device 1 is mounted.

[0020] The reserve tank 101 is a container that temporarily stores the coolant 10 to be circulated in the coolant circulation circuit 100. The other end of the first pipe 105a on the upstream side and the end of the sixth pipe 105f on the downstream side are connected to the bottom of the reserve tank 101 in the flow direction of the coolant 10. In addition, a gas-only pipe 108 is connected to the upper part of the side wall of the reserve tank 101, at a position above the highest level that the liquid level of the coolant 10 can reach in the reserve tank 101. A lid member 111 that closes an opening on the upper surface side of the reserve tank 101 is provided on the upper part of the reserve tank 101. The lid member 111 is made of a resin material (e.g., polyvinyl chloride) that is permeable to hydrogen gas and oxygen gas. In addition, a pressure regulating valve 121 is provided at the upper part of the side wall of reserve tank 101, between the connection part with gas-only pipe 108 and cover member 111. When the pressure inside reserve tank 101 reaches or exceeds a predetermined pressure, a valve opens to discharge gas from reserve tank 101 and adjust the pressure inside reserve tank 101.

[0021] The chiller 102 is disposed downstream of the reserve tank 101 in the flow direction of the coolant 10. The chiller 102 is, for example, a heat exchanger for cooling the coolant 10 by exchanging heat with a refrigerant circulating in a refrigeration cycle circuit provided inside the chiller 102.

[0022] The oil pump 103 is disposed downstream of the chiller 102 in the flow direction of the coolant 10. The oil pump 103 pumps the coolant 10 and circulates it through the reserve tank 101, the chiller 102, and the coolers 104a and 104b in this order.

[0023] The coolers 104A, 104B are heat exchangers that exchange heat between the coolant 10 flowing through the coolants 104A, 104B and the assembled batteries 2A, 2B. That is, the coolers 104A, 104B absorb heat from the assembled batteries 2A, 2B into the coolant 10 as the coolant 10 circulates in the coolant circulation circuit 100, thereby cooling the assembled batteries 2A, 2B. The coolers 104A, 104B are connected to the sides of the assembled battery 2 in a manner capable of thermal conduction.

[0024] The mixed water collection tank 106 is a container for collecting water mixed into the coolant 10 circulating through the coolant circulation circuit 100. A lower end of the fourth pipe 105d is connected to the upper part of the mixed water collection tank 106 in the vertical direction, and a part of the coolant 10 circulating through the coolant circulation circuit 100 can be stored together with the water mixed into the coolant 10. In the mixed water collection tank 106, the coolant 10 and the water are separated due to the relationship in specific gravity between the coolant 10 made of insulating oil and the water mixed into the coolant 10, and the water accumulates in the lower part of the mixed water collection tank 106.

[0025] The electrode device 107 is provided with a positive electrode 107a and a negative electrode 107b for electrolyzing water, which are installed at the lowest position in the mixed-water collection tank 106. In the electrode device 107, electricity is applied to the positive electrode 107a and the negative electrode 107b, whereby the water accumulated in the mixed-water collection tank 106 is electrolyzed to generate hydrogen gas and oxygen gas.

[0026] The lower end of the gas-only pipe 108 is connected to the top of the mixed water collection tank 106, and the upper end is connected to the top of the reserve tank 101, above the highest possible liquid level of the coolant 10 in the reserve tank 101. The gas-only pipe 108 is a pipe dedicated to gas that guides the hydrogen gas and oxygen gas generated by electrolyzing the water in the mixed water collection tank 106 by the electrode device 107 to the reserve tank 101.

[0027] In the battery cooling device 1 according to the first embodiment, when water is mixed into the cooling liquid 10 made of insulating oil, the water is heavier than the cooling liquid 10, and as the cooling liquid 10 is circulated by the oil pump 103, the water in the cooling liquid 10 gradually accumulates in the mixed water collection tank 106 from the lower end of the fourth pipe 105d. In addition, in the battery cooling device 1 according to the first embodiment, the coolers 104A and 104B are inclined at an angle θ with respect to the horizontal direction so that the downstream end is vertically higher than the upstream end in the flow direction of the cooling liquid 10. This makes it possible to guide the water in the cooling liquid 10 that has accumulated in the coolers 104A and 104B, etc., to the mixed water collection tank 106 by gravity via the fourth pipe 105d.

[0028] The water stored in the mixed water collection tank 106 is electrolyzed by applying a predetermined voltage to the positive electrode 107a and the negative electrode 107b of the electrode device 107 installed at the lowest position in the mixed water collection tank 106, and hydrogen gas and oxygen gas are generated. The hydrogen gas and oxygen gas generated by electrolyzing the water in the cooling liquid 10 pass through the cooling liquid 10 stored in the mixed water collection tank 106 and reach the upper part of the mixed water collection tank 106, and are guided to the reserve tank 101 through the gas dedicated pipe 108 and collected in the reserve tank 101. Note that hydrogen gas is much lighter than the air in the reserve tank 101, so it moves relatively quickly through the gas dedicated pipe 108 to the reserve tank 101. Also, oxygen gas is lighter than the air in the reserve tank 101, although not as light as hydrogen gas, so it gradually moves through the gas dedicated pipe 108 to the reserve tank 101.

[0029] The hydrogen gas and oxygen gas collected in the reserve tank 101 are released to the outside of the reserve tank 101 through the lid member 111 provided on the top of the reserve tank 101. As a result, in the battery cooling device 1 according to the first embodiment, the hydrogen gas and oxygen gas can be gradually released and diffused to the outside of the reserve tank 101 from the lid member 111 without going through the pressure regulating valve 121 provided on the reserve tank 101, making it difficult for a flammable phenomenon to occur outside the reserve tank 101 and, ultimately, outside the coolant circulation circuit 100.

[0030] In this way, in the battery cooling device 1 of embodiment 1, water mixed into the coolant 10 made of insulating oil can be reliably and safely discharged outside the coolant circulation circuit 100, and it is possible to suppress a decrease in the insulating properties of the insulating oil due to water mixing into the coolant 10, and a decrease in cooling performance due to the accumulation of hydrogen gas and oxygen gas generated by electrolyzing the water in the coolant 10 in various parts of the coolant circulation circuit 100.

[0031] (Embodiment 2) A battery cooling device according to a second embodiment of the present invention will be described below. Note that the description of the second embodiment common to the first embodiment will be omitted as appropriate.

[0032] FIG. 2 is a diagram showing a schematic configuration of a battery cooling device 1 according to a second embodiment. As shown in FIG. 2, the battery cooling device 1 according to the second embodiment includes, in addition to an electronic control device 3 and a coolant circulation circuit 100, a sub-coolant circulation circuit (second coolant circulation circuit) 200 that circulates a coolant (second coolant) 20 made of insulating oil for cooling the assembled batteries 2A and 2B separately from the coolant circulation circuit 100. The sub-coolant circulation circuit 200 is a separate cooling system configuration that can perform a minimum level of battery cooling. In the battery cooling device 1 according to the second embodiment, the same type of insulating oil is used as the coolant 10 circulating in the coolant circulation circuit 100 and the coolant 20 circulating in the sub-coolant circulation circuit 200.

[0033] In the battery cooling device 1 of embodiment 2, even if the coolant circulation circuit 100 is in a failed state, the sub-coolant circulation circuit 200 cools the assembled batteries 2A, 2B, allowing power to be output from the assembled batteries 2A, 2B, thereby enabling the vehicle to travel at a constant speed for evacuation.

[0034] In the battery cooling device 1 according to the second embodiment, the coolant circulation circuit 100 is provided with a pressure sensor 131 for detecting the pressure inside the reserve tank 101, at an upper portion of the side wall of the reserve tank 101.

[0035] In the battery cooling device 1 according to the second embodiment, the lower end of a special passage 109 for guiding and collecting gas into the reserve tank 101 is connected to a bent portion at the upper part of the fifth pipe 105e connected to the downstream side of the cooler 104B in the flow direction of the coolant 10 as a portion where gas in the coolant circulation circuit 100 is likely to accumulate. The upper end of the special passage 109 is inserted from the bottom of the reserve tank 101 and connected to the reserve tank 101 so as to be located above the highest level that the liquid level of the coolant 10 can take in the reserve tank 101. In the coolant circulation circuit 100 according to the second embodiment, the coolers 104A and 104B are inclined (slant) with respect to the horizontal, so that gas is likely to accumulate from the fifth pipe 105e connected to the downstream side of the coolers 104A and 104B in the flow direction of the coolant 10 toward the reserve tank 101 through the special passage 109. This allows the gas accumulated in the bent portion at the top of the fifth pipe 105e to be guided to the reserve tank 101 via the special passage 109 and collected therein.

[0036] The sub-coolant circulation circuit 200 is configured by providing a reserve tank (second reserve tank) 201, a chiller 202, an oil pump 203, a cooler 204, a coolant pipe 205, and a communication pipe 206. In the second embodiment, the basic configurations of the reserve tank 201, the chiller 202, the oil pump 203, the cooler 204, and the like provided in the sub-coolant circulation circuit 200 are almost the same as the reserve tank 101, the chiller 102, the oil pump 103, and the cooler 104 provided in the coolant circulation circuit 100, and therefore the description thereof will be omitted as appropriate.

[0037] In the sub-coolant circulation circuit 200, the reserve tank 201, the chiller 202, the oil pump 203, and the cooler 204 are connected in a ring shape by the coolant pipe 205. In this case, the reserve tank 201 is installed in a place where the flow of gas in the sub-coolant circulation circuit 200 is not stagnated or is unlikely to stagnate. In addition, the cooler 204 is arranged at a predetermined angle (for example, angle θ) with respect to the horizontal direction so that the downstream end in the flow direction of the coolant 20 is vertically higher than the upstream end. This makes it possible to guide the water in the coolant 20 that has accumulated in the cooler 204, etc., to the mixed water accumulation tank 106 by gravity via the third pipe 205c and the fourth pipe 205d.

[0038] The cooling liquid piping 205 is composed of a first pipe 205a connecting the reserve tank 201 and the chiller 202, a second pipe 205b connecting the chiller 202 and the oil pump 203, a third pipe 205c and a fourth pipe 205d connecting the oil pump 203 and the cooler 204, and a fifth pipe 205e connecting the cooler 204 and the reserve tank 201. The third pipe 205c is arranged at an angle θ with respect to the horizontal direction so that the downstream end in the flow direction of the cooling liquid 20 is vertically higher than the upstream end. In addition, the downstream end of the third pipe 205c in the flow direction of the cooling liquid 20 is inserted into the mixed water accumulation tank 106 from the side wall of the mixed water accumulation tank 106, and a part of the cooling liquid 20 circulating in the sub-cooling liquid circulation circuit 200 can be stored together with the water mixed in the cooling liquid 20.

[0039] The communicating pipe 206 is a pipe that communicates between a space above the highest possible position of the liquid level of the coolant 20 in the reserve tank 201 of the sub-coolant circulation circuit 200 and a space above the highest possible position of the liquid level of the coolant 10 in the reserve tank 101 of the coolant circulation circuit 100, and functions as a path through which gas can pass from inside the reserve tank 201 to inside the reserve tank 101. The end of the communicating pipe 206 on the reserve tank 101 side is inserted into the reserve tank 101 from the cover member 111 of the reserve tank 101, and is located above the highest possible position of the liquid level of the coolant 10 in the reserve tank 101. The end of the communicating pipe 206 on the reserve tank 201 side is inserted into the reserve tank 201 through the cover member 211 of the reserve tank 201, and is located above the highest possible liquid level of the coolant 20 in the reserve tank 201.

[0040] The lid member 211 of the reserve tank 201 is made of a resin material (such as polyvinyl chloride) that is permeable to hydrogen gas and oxygen gas, similar to the lid member 111 of the reserve tank 101. In the battery cooling device 1 according to the second embodiment, the pressure regulating valve 121 provided in the reserve tank 101 is shared by the reserve tank 101 and the reserve tank 201.

[0041] In the battery cooling device 1 according to the second embodiment, the pressure sensor 131 can detect a temporary pressure rise in the reserve tank 101 caused by gas generation in at least one of the coolant circulation circuit 100 and the sub-coolant circulation circuit 200. Then, based on the detection result, the electronic control device 3 can perform input / output limiting control of the assembled batteries 2A, 2B to compensate for insufficient cooling of the assembled batteries 2A, 2B. Also, in the battery cooling device 1 according to the second embodiment, the pressure sensor 131 can be shared between the coolant circulation circuit 100 and the sub-coolant circulation circuit 200, so the number of sensors to be installed can be reduced.

[0042] In the battery cooling device 1 according to the second embodiment, the electronic control device 3 may control the positive electrode 107a and the negative electrode 107b of the electrode device 107 to be energized only when the SOC of the assembled batteries 2A, 2B is equal to or higher than a reference value, or when the regenerative power during vehicle deceleration is equal to or higher than a predetermined value, and power cannot be efficiently stored in the assembled batteries 2A, 2B. This can reduce unnecessary power consumption. Also, in the battery cooling device 1 according to the second embodiment, the power required for electrolysis of water in the electrode device 107 is provided by utilizing surplus power of the vehicle, thereby making it possible to save fuel required for battery charging.

[0043] In the battery cooling device 1 according to the second embodiment, the reserve tank 101 is installed at a position in the coolant circulation circuit 100 where the piping is simplified, and the special passage 109 makes it difficult for gas to accumulate in the coolant piping 105, so that hydrogen gas and oxygen gas generated by electrolysis of water in the coolant 10 outside the electrode device 107 are also guided to and collected in the reserve tank 101. The hydrogen gas and oxygen gas thus collected in the reserve tank 101 are then released from inside the reserve tank 101 through the lid member 111 to the outside of the reserve tank 101 and ultimately to the coolant circulation circuit 100 side, thereby making it possible to suppress the occurrence of poor cooling caused by the presence of gas in the coolant 10. [Explanation of symbols]

[0044] 1 Battery cooling device 2A,2B assembled battery 3. Electronic Control Unit 10,20 Coolant 100 Coolant circulation circuit 101,201 Reserve tank 102,202 Chiller 103,203 Oil pump 104A,104B,204 Cooler 105,205 Coolant piping 105a, 205a First pipe 105b, 205b Second piping 105c, 205c 3rd piping 105d, 205d 4th pipe 105e, 205e 5th pipe 105f 6th Pipe 107 Electrode device 107a Positive electrode 107b Negative electrode 108 Gas-only piping 109 Special passage 111,211 Cover member 121 Pressure Regulating Valve 131 Pressure Sensor 206 Communication pipe

Claims

1. A battery cooling device including a first coolant circulation circuit that circulates a first coolant made of insulating oil for cooling a battery, The first coolant circulation circuit includes at least a first reserve tank for temporarily storing the first cooling liquid; a mixed water collecting tank for collecting water mixed in the first cooling liquid; An electrode device for electrolyzing the water stored in the mixed water collection tank; a gas-only pipe for guiding hydrogen gas and oxygen gas generated by electrolyzing the water by the electrode device to the first reserve tank separately from the first cooling liquid; It is composed of a first cover member is provided on an upper portion of the first reserve tank to close an opening on an upper surface side of the first reserve tank; A battery cooling device characterized in that the first cover member is made of a resin material that is permeable to hydrogen gas and oxygen gas.

2. a second coolant circulation circuit that circulates a second coolant made of insulating oil for cooling the battery, separately from the first coolant circulation circuit; The second coolant circulation circuit includes at least a second reserve tank for temporarily storing the second cooling liquid; A pipe for guiding water mixed in the second cooling liquid to the mixed water collecting tank; 2. The battery cooling device according to claim 1, characterized in that the battery cooling device is configured by:

3. The first reserve tank is provided with a pressure sensor that detects a pressure in the first reserve tank, The battery cooling device as described in claim 2, characterized in that it is provided with a connecting pipe connecting a space in the second reserve tank above the highest possible position of the liquid level of the second cooling liquid and a space in the first reserve tank above the highest possible position of the liquid level of the first cooling liquid.

Images