Temperature control device

Abstract

When cooling multiple batteries, temperature control is performed to suppress temperature differences between the batteries. [Solution] The temperature control device comprises a plurality of columnar batteries arranged in close proximity to each other, a housing section containing the plurality of batteries, a heat transfer medium filled in the housing section which changes between gas and liquid depending on the temperature, a covering section that covers the sides of each of the plurality of batteries and generates flow resistance of the liquid heat transfer medium flowing along the sides, and a cooling section positioned vertically above the plurality of batteries in the housing section to cool the heat transfer medium, wherein the plurality of batteries are in contact with adjacent batteries at least in part via the covering section, the heat transfer medium is condensed and liquefied by the cooling section and vaporized by the heat of the plurality of batteries.

Description

Technical Field

[0001] The present invention relates to a temperature control device.

Background Art

[0002] As batteries, a plurality of cylindrical batteries arranged side by side in the horizontal direction are known (for example, see Patent Document 1). The plurality of cylindrical batteries described in Patent Document 1 are arranged side by side in a case in a state where they do not contact each other. Between the cylindrical batteries, spacers extending vertically downward from the upper surface of the case and spacers extending vertically upward from the lower surface of the case are arranged. The cooling water supplied horizontally in the case is prevented from passing linearly through the case by the spacers.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the battery cooling method described in Patent Document 1, the batteries near the inlet in the case are well cooled, but the temperature of the cooling water near the outlet is higher than that near the inlet. As a result, the temperature of the batteries near the outlet becomes higher than the temperature of the batteries near the inlet, and there is a risk that the temperature difference generated between the plurality of batteries arranged in the case will increase. When a plurality of batteries arranged in the case are used as one module, if the temperature difference between the batteries is large, the capacity deterioration of the higher-temperature batteries tends to progress. As a result, if overcharging or over-discharging occurs in batteries with different capacity deteriorations, not only will the battery life deteriorate, but there is also a risk that the battery safety will decrease. Therefore, it is desired to minimize the temperature difference between the plurality of batteries used as one module.

[0005] The present invention has been made to solve at least some of the above-mentioned problems, and aims to provide temperature control that suppresses temperature differences between batteries when cooling multiple batteries. [Means for solving the problem]

[0006] The present invention has been made to solve at least some of the above-mentioned problems and can be realized in the following forms.

[0007] (1) According to one embodiment of the present invention, a temperature control device is provided. This temperature control device comprises a plurality of columnar batteries arranged in close proximity to each other, a housing section housing the plurality of batteries, a heat transfer medium filled in the housing section which changes between gas and liquid depending on the temperature, a covering section that covers each side of the plurality of batteries and generates flow resistance of the liquid heat transfer medium flowing along the side, and a cooling section arranged vertically above the plurality of batteries in the housing section and cooling the heat transfer medium, wherein the plurality of batteries are in contact with adjacent batteries at least in part via the covering section, the heat transfer medium is condensed and liquefied by the cooling section and vaporized by the heat of the plurality of batteries.

[0008] In this configuration, multiple batteries that generate heat during charging and discharging are cooled by vapor heat transport using the latent heat of the heat transfer medium filled in the housing. Each side of the columnar batteries is covered with a coating that prevents the liquid heat transfer medium from flowing vertically downward. As a result, efficient heat exchange occurs between the liquid heat transfer medium flowing through the coating and the surface of the batteries. The vaporized heat transfer medium moves vertically upward through the space in the housing and within the coating, where it is cooled and condensed by the cooling unit. The condensed liquid heat transfer medium cools the batteries again. Compared to liquid cooling methods, the batteries are cooled more efficiently by vapor heat transport. As a result, the temperature difference between the maximum and minimum temperatures of the multiple batteries housed in the housing is suppressed. This allows for temperature control that suppresses the temperature difference between the multiple batteries when the multiple batteries arranged in the housing are used as a single module. As a result, overcharging or over-discharging of batteries with different capacity degradations within the housing is suppressed, and the deterioration of battery life is suppressed. Furthermore, in this configuration, since the multiple columnar batteries are arranged adjacent to each other within the housing, the volume ratio of the multiple batteries to the total volume of the housing is improved. This improvement in volume ratio leads to an improvement in the energy density ratio, which is the energy of the batteries per unit volume. In other words, in this configuration, the temperature difference generated between batteries is suppressed by uniform and high-power vapor heat transport.

[0009] (2) In the temperature control device according to the above embodiment, the covering portion may be made of a porous material. With this configuration, the porous coating allows the liquid heat transfer medium to remain on the sides of the battery for a longer period of time. This enables efficient cooling of the battery using the latent heat of the liquid heat transfer medium.

[0010] (3) In the above embodiment of the temperature control device, the device further comprises an upper busbar that is positioned vertically above the plurality of batteries in the housing and vertically below the cooling unit, is electrically connected to the terminals on one side of each of the plurality of batteries, and has a flat plate shape that extends horizontally, and the cooling unit comprises a flow path forming unit that extends horizontally and forms a plurality of refrigerant flow paths through which refrigerant flows, and a hanging part that covers at least a part of the outer wall of the flow path forming unit, extends vertically downward from the lower end of the outer wall of the flow path forming unit in a range spaced apart from the upper busbar, and is made of a porous material. In this configuration, the upper busbar, which is electrically connected to the terminals of each battery, generates heat when current flows through it. In particular, during high-rate charging and discharging, the upper busbar becomes hot, and the area of ​​the upper busbar connected to the battery terminals becomes even hotter. In this configuration, the upper busbar has a flat plate shape that extends horizontally. Therefore, much of the liquid heat transfer medium dripping vertically downward from the cooling section comes into contact with the upper busbar, and the upper busbar is cooled. Also, since the hanging section is positioned apart from the upper busbar, leakage current between the hanging section and the flow path forming section via the hanging section and the upper busbar is suppressed. On the other hand, the hanging section is located vertically below the lower end of the outer wall of the flow path forming section. Therefore, the heat transfer medium that has been cooled and liquefied by the refrigerant flowing through the refrigerant flow path is quickly dripped vertically downward through the hanging section. As a result, the upper busbar and batteries are efficiently cooled by heat vapor transport by the cooling section.

[0011] (4) In the temperature control device according to the above embodiment, the upper busbar has through holes formed in at least a portion of the position opposite to the covering portion, and the cooling portion may be positioned vertically above the upper busbar at a distance from the upper busbar. In this configuration, through holes are formed in the upper busbar at a position opposite the covering portion. Therefore, a portion of the liquid heat transfer medium dripping from the cooling section is supplied to the covering portion without contacting the upper busbar. As a result, in this configuration, the area around the terminals that become particularly hot in the upper busbar is cooled, suppressing localized overheating, and the battery is also cooled by the liquid heat transfer medium supplied to the covering portion.

[0012] (5) In the temperature control device according to the above embodiment, the device may further include a liquid receiving section for storing the heat transfer medium, which is located vertically below the plurality of batteries in the housing section and is electrically connected to the terminals on the other side of each of the plurality of batteries, and a bottom busbar located vertically below the liquid receiving section and electrically connected to the liquid receiving section. In this configuration, the electrolyte reservoir, which is electrically connected to the terminals on the vertically lower side of the battery, is electrically connected to the bottom busbar located vertically below the electrolyte reservoir. That is, the current flowing through the battery flows between the battery and the bottom busbar via the electrolyte reservoir. The electrolyte reservoir and bottom busbar, like the upper busbar, generate heat when current flows through them. The heat transfer fluid of the liquid that flows vertically downwards from the battery is stored in the electrolyte reservoir and used to cool the electrolyte reservoir and the bottom busbar. In particular, the vertically lower surface of the battery is in direct contact with the liquid heat transfer fluid, resulting in a high heat flow rate and thus a form of boiling heat transfer. Therefore, even with a small heat transfer area, the high heat flow rate enables cooling of the battery and the bottom busbar. In addition, the vaporization of the liquid heat transfer fluid that flows vertically downwards increases the flow rate of the heat transfer fluid circulating within the reservoir, suppressing dry-out, which is likely to occur on the vertically lower side of the battery.

[0013] (6) In the above embodiment of the temperature control device, the device may further include: a first terminal electrically connected to the bottom busbar for extracting power supplied from the plurality of batteries; a second terminal electrically connected to the bottom busbar for extracting power supplied from the plurality of batteries, the second terminal having a lower electrical resistance than the first terminal; and a switching unit that switches to connect to the second terminal under steady conditions and to the first terminal under high load conditions when extracting power supplied from the plurality of batteries. In this configuration, the terminal connected to the battery is switched between a first terminal and a second terminal with different electrical resistances, resulting in different heat generation at each terminal during battery charging and discharging. Under high load conditions, the flow rate of the heat transfer medium circulating within the housing may be insufficient compared to steady-state conditions, preventing adequate cooling of the battery and other components by steam heat transport. In this configuration, under high load conditions, the battery is connected to the high-resistance first terminal, utilizing the high heat generation of the first terminal to compensate for the insufficient circulation of the heat transfer medium. As a result, the output of steam heat transport under high load conditions is improved. On the other hand, under steady-state conditions with lower loads than high load conditions, power loss at the second terminal is reduced by connecting an external load to the second terminal.

[0014] (7) In the temperature control device according to the above embodiment, the first terminal is located in the center of the bottom busbar, the second terminal is located on the outer circumference of the bottom busbar, and in the liquid receiving section, the heat transfer medium of the liquid stored in the liquid receiving section may move more easily to the vertically downward side of the liquid receiving section in the central section than on the outer circumference side. In this configuration, the liquid heat transfer medium stored in the liquid receiving section tends to accumulate vertically downwards in the central part. The first terminal, which has high resistance, is positioned in the central area where the heat transfer medium tends to accumulate. Therefore, the vaporization of the heat transfer medium caused by the heat generated at the first terminal under high load conditions is efficiently performed. As a result, the output of steam heat transport under high load conditions is further improved.

[0015] (8) In the temperature control device according to the above embodiment, the device further includes a temperature acquisition unit that acquires the temperature of a battery, and the switching unit may determine that it is in a steady state when the acquired temperature of the battery is below a threshold, and determine that it is in a high-load state when the temperature of the battery is above a threshold. In this configuration, the steady-state and high-load conditions of the battery are determined by the battery temperature. A high battery temperature indicates that the battery and other components require more cooling. In this configuration, the steady-state and high-load conditions are easily determined by the battery temperature, and the output of steam heat transport is increased using the heat generated at the first terminal when necessary.

[0016] Note that the present invention can be implemented in various forms, for example, a temperature control device, a cooling device, a temperature control device for a secondary battery, an electric vehicle, a temperature control method, a system including these devices, a computer program for executing these devices, a server device for distributing this computer program, a non-temporary storage medium storing the computer program, and the like.

Brief Description of the Drawings

[0017] [Figure 1] It is a schematic perspective view of a battery temperature control system as an embodiment of the present invention. [Figure 2] It is a schematic top view of the battery in the case. [Figure 3] It is a schematic perspective view of the flow path forming portion and the hanging porous body. [Figure 4] It is a schematic perspective view of the connecting porous body and the upper bus bar. [Figure 5] It is a schematic exploded perspective view of the bottom bus bar and the heating portion. [Figure 6] It is an explanatory diagram of the temperature distribution in the battery immediately after the discharge is completed. [Figure 7] It is an explanatory diagram of the temperature distribution in the battery immediately after the discharge is completed. [Figure 8] It is an explanatory diagram of the time change of the battery temperature. [Figure 9] It is an explanatory diagram of the temperature distribution in the battery of the comparative example immediately after the discharge is completed. [Figure 10] It is an explanatory diagram of the time change of the battery temperature of the comparative example. [Figure 11] It is an explanatory diagram of the volume ratio and the volume energy density ratio according to the arrangement of a plurality of batteries. [Figure 12] It is a schematic top view of the upper bus bar in the second embodiment. [Figure 13] It is a schematic cross-sectional view of the upper bus bar in the second embodiment. [Figure 14] It is a schematic perspective view of the bottom bus bar and the liquid receiving portion in the second embodiment. [Figure 15]This is a schematic bottom view of the bottom busbar of the second embodiment. [Figure 16] This is a schematic top view of the bottom busbar of the third embodiment. [Figure 17] This is a schematic cross-sectional view of the bottom busbar of the third embodiment. [Figure 18] This is a schematic perspective view of the bottom busbar of the fourth embodiment. [Figure 19] This is an explanatory diagram of the first and second terminals in the fourth embodiment. [Modes for carrying out the invention]

[0018] <First Embodiment> Figures 1 and 2 are schematic diagrams of a temperature control system (temperature control device) 100 for a battery 10 as one embodiment of the present invention. In this embodiment, the temperature control system 100 cools seven batteries 10 housed in a case 20 by vapor heat transport of a fluorocarbon-based medium 25 filled in the case 20. In this embodiment, the fluorocarbon-based medium 25 vaporizes due to the heat of the batteries 10, condenses in a cooling unit 30 located vertically above the batteries 10, and passes through a cylindrical porous body 15 covering the sides of the cylindrical batteries 10. The liquid fluorocarbon-based medium 25 passing through the cylindrical porous body 15 vaporizes again due to the heat of the batteries 10.

[0019] Figure 1 shows a schematic perspective view of the temperature control system 100. Figure 2 shows a schematic top view of the batteries 10 housed in the case 20, viewed from vertically above. As shown in Figure 1, the temperature control system 100 comprises seven cylindrical batteries 10 arranged in close proximity to each other, a cylindrical porous body (covering part) 15 covering the sides of each of the seven batteries 10, an upper busbar 40 located vertically above the seven batteries, a cooling unit 30 positioned vertically above the upper busbar 40 at a distance from the upper busbar 40, a bottom busbar 50 located vertically below the seven batteries 10, and a heating unit 60 positioned vertically below the bottom busbar 50 at a distance from the bottom busbar 50.

[0020] The battery 10 in this embodiment is a rechargeable secondary battery. Figure 2 shows a schematic top view of a part of the temperature control system 100 as seen from vertically above. In Figure 2, the cooling section 30, the upper bus bar 40, the bottom bus bar 50, and the heating section 60 are omitted from the illustration. Also in Figure 2, different types of hatching are applied to the battery 10 and the cylindrical porous body 15, respectively. As shown in Figure 2, the temperature control system 100 further comprises a case (housing section) 20 that houses seven batteries 10, and a fluorocarbon-based medium (heat transfer medium) 25 filled inside the case 20. Note that in Figure 1, the case 20 and the fluorocarbon-based medium 25 are omitted from the illustration. In addition to the seven batteries 10 and the fluorocarbon-based medium 25, the case 20 houses the cooling section 30, the upper bus bar 40, the bottom bus bar 50, and the heating section 60 shown in Figure 1. Parts of the upper busbar 40 and the lower busbar 50 protrude from the case 20 and are connected to external devices.

[0021] As shown in Figure 2, the seven batteries 10 have the same shape. The batteries 10 have a central axis parallel to the vertical direction and are arranged in a horizontal direction perpendicular to the vertical direction. The seven batteries 10 are arranged in a so-called hexagonal packing configuration, so that they are in contact with other adjacent batteries 10 via the cylindrical porous body 15 covering their sides. In this embodiment, the Cartesian coordinate system CS shown in Figures 1 and 2 is defined. The Cartesian coordinate system CS consists of a Z axis parallel to the vertical direction and X and Y axes parallel to the horizontal direction. The Y axis is parallel to the line passing through the central axes of three of the seven batteries in the hexagonal packing configuration. The X axis is perpendicular to the Y and Z axes. The Cartesian coordinate system CS corresponds to the Cartesian coordinate system CS shown in Figure 3 and subsequent figures.

[0022] As shown in Figure 2, there is a space SP1 within the case 20 where the battery 10 and cylindrical porous body 15 are not placed. In this embodiment, the vapor pressure and type of the fluorocarbon medium 25 filled in the case 20 are appropriately set so that its boiling point is in the range of 15 degrees Celsius (°C) to 35 degrees Celsius (for example, 27°C). Therefore, the fluorocarbon medium 25 in the case 20 changes between liquid and gas depending on the heat generation state of the battery 10. The cylindrical porous body 15 covering the sides of each battery 10 is made of porous material. Therefore, it can also be said that the cylindrical porous body 15 generates flow resistance for the liquid fluorocarbon medium 25 flowing along the sides of the battery 10. The cylindrical porous body 15 retains the liquid fluorocarbon medium 25 for a longer period of time compared to the space SP1 where the cylindrical porous body 15 is not placed.

[0023] The cooling unit 30 shown in Figure 1 comprises a plurality of flow path forming sections 31 that form a refrigerant flow path 32 through which a refrigerant that cools the inside of the case 20 flows, a hanging porous body (hanging section) 34 (not shown in Figures 1 and 2) that covers the outer wall of the side surface of the flow path forming section 31, and a connecting porous body 33 that is spaced apart from the flow path forming section 31 and the hanging porous body 34 and positioned vertically below the flow path forming section 31. In this embodiment, the flow path forming section 31 is formed so that the refrigerant flow path 32 extends along the Y axis. The flow path forming section 31 has outer walls parallel to the vertical and horizontal directions so that the cross-section of the refrigerant flow path 32 is rectangular in shape perpendicular to the Y axis. The hanging porous body 34 is arranged on the outer walls of the plurality of flow path forming sections 31.

[0024] Figure 3 is a schematic perspective view of the channel forming section 31 and the hanging porous body 34. Figure 3 shows an enlarged schematic perspective view of a portion of the channel forming section 31 and the hanging porous body 34 that covers the outer wall of the channel forming section 31 on the negative X-axis side. As shown in Figure 3, a space SP2 (Figure 3) is formed between adjacent hanging porous bodies 34 in the X-axis direction. The hanging porous body 34 extends vertically downward from the lower end of the outer wall of the channel forming section 31. The hanging porous body 34 is made of a porous material. The lower side of the hanging porous body 34 is connected to the connecting porous body 33. The fluorocarbon-based medium 25, which has been vaporized by the heat generated by the battery 10, is cooled and condensed into liquid by the refrigerant flowing through the refrigerant channel 32 via the channel forming section 31. The liquefied fluorocarbon-based medium 25 passes through the hanging porous body 34 and the connecting porous body 33 connected to the hanging porous body 34.

[0025] Figure 4 is a schematic perspective view of the connected porous body 33 and the upper busbar 40. Figure 4 shows the connected porous body 33, the upper busbar 40, and a portion of the vertically upper side of the battery 10 and the cylindrical porous body 15. The connected porous body 33 has a predetermined thickness along the vertical direction and is formed by a plurality of flat plates extending in the Y-axis direction. The plurality of flat plates PL forming the connected porous body 33 are connected to each other by ribs LB extending in the X-axis direction, as shown in Figure 4. The connected porous body 33 is fixed to the case 20 and is connected to the hanging porous body 34 located vertically above it, and is spaced apart from the upper busbar 40 located vertically below it. The lower side of the connected porous body 33 is connected to the cylindrical porous body 15 that covers each battery 10. The connected porous body 33 is formed of porous material. Therefore, the liquid fluorocarbon medium 25 that flows from the hanging porous body 34 into the connected porous body 33 is diffused into the connected porous body 33 by capillary action.

[0026] The upper busbar 40 shown in Figure 4 is positioned vertically above the seven batteries 10 and is electrically connected to the vertically upward terminals of each of the seven batteries 10. In this embodiment, each battery 10 has terminals formed on the vertically upward and vertically downward sides on a central axis parallel to the vertical direction. When viewed from the vertical direction, the upper busbar 40 has a broken line shape in which its longitudinal axis is composed of straight lines parallel to the X and Y axes. As shown in Figure 4, the cylindrical porous body 15 covering the sides of the batteries 10 has a shape in which a portion of the vertically upward side is cut out so as not to come into contact with the upper busbar 40.

[0027] Figure 5 is a schematic exploded perspective view of the bottom busbar 50 and the heating section 60. As shown in Figure 5, the temperature control system 100 further includes a plurality of insulating supports 70 positioned between the bottom busbar 50 and the heating section 60. In Figure 5, the batteries 10 housed in the case 20 are omitted from the illustration. The bottom busbar 50 is electrically connected to the vertically downward terminals of each of the seven batteries 10. Although not shown in Figure 5, the cylindrical porous body 15 covering the sides of the batteries 10 has a shape in which a portion of the vertically downward side is cut out so as not to come into contact with the bottom busbar 50, similar to the vertically upward side.

[0028] The heating unit 60 heats the fluorocarbon-based medium 25 inside the case 20 according to the charge and discharge state of the battery 10. For example, the heating unit 60 may be a heater that is heated by the supplied power, or a structure in which a high-temperature heat transfer medium is supplied into the heating unit 60. The heating unit 60 heats the fluorocarbon-based medium 25 when the battery 10 generates a large amount of heat and it is desired to increase the circulation speed of the fluorocarbon-based medium 25 that circulates inside the case 20 through a phase change between liquid and gas.

[0029] Multiple insulating supports 70 are positioned between the bottom busbar 50 and the heating section 60. Each insulating support 70 has a disc shape with a predetermined thickness in the vertical direction. The insulating supports 70 are electrically insulating. In the exploded perspective view of Figure 5, the insulating supports 70 and the bottom busbar 50 are shown separated, but the upper surface of each disc-shaped insulating support 70 is in contact with the lower surface of the bottom busbar 50. Due to the presence of the insulating supports 70, the bottom busbar 50 is supported without contacting the heating section 60.

[0030] Figures 6 and 7 are explanatory diagrams of the temperature distribution inside the battery 10 immediately after discharge is complete. Figures 6 and 7 show the simulation results of the temperature distribution inside the case 20, including the battery 10, immediately after discharge until the State of Charge (SOC), which represents the charge state of the battery 10 at 3C, drops from 0.95 to 0.1. In the simulation results shown in Figures 6 and 7, a fluorocarbon-based medium 25 with a boiling point of 27°C is used. In Figures 6 and 7, as shown in Figures 6(a) and 7(a), the temperature was measured at different locations in the cross-section of the case 20. Figure 6(b) shows the temperature distribution at a location that passes through the central axis of the battery 10 located in the middle of the seven batteries 10, as shown in Figure 6(a), and also passes through the contact points of the cylindrical porous bodies 15 of the other batteries 10. On the other hand, Figure 7(b) shows the temperature distribution at locations that pass through the central axes of three of the seven batteries 10, as shown in Figure 7(a).

[0031] The vertical height dimension of the battery 10 shown in Figures 6 and 7 is 80 mm. The curves C1a and C2a (solid lines) shown in Figures 6(b) and 7(b) represent the temperature distribution at a height of 10 mm from the vertical bottom of the battery 10. The curves C1ba and C2b (dashed lines) represent the temperature distribution at a height of 40 mm from the vertical bottom of the battery 10. The curves C1c and C2c (dotted lines) represent the temperature distribution at a height of 70 mm from the vertical bottom of the battery 10. The horizontal axis in Figures 6(b) and 7(b) represents the normalized value of the distance from the central axis of the middle battery 10 relative to the linear distance of the temperature distribution. Furthermore, the position of the contact point A of the cylindrical porous body 15 of the two adjacent batteries 10 in Figure 6(a) corresponds to the center position on the X axis of region A enclosed by the thin dashed line in Figure 6(b).

[0032] As shown by curves C1b and C2b in Figures 6(b) and 7(b), the center of the middle battery 10 among the seven batteries reaches the highest temperature at a height of 40 mm. Comparing the temperature at the center axis of the middle battery 10, which is the highest temperature, with the temperature at the lowest temperature at a height of 10 mm, the temperature difference was 2.9°C, as shown in Figure 7(b). Furthermore, from the simulation results shown in Figure 7(b), it was found that in all batteries 10, the center axis was the hottest, and the outer cylindrical porous body 15 side was the coldest.

[0033] As shown in Figure 7, the temperature difference between the outer peripheral space inside the case 20 through which the gaseous fluorocarbon medium 25 flows and the temperature of the cylindrical porous body 15 at a height of 40 mm from the battery 10 located on the outer peripheral was 2.6°C. The temperature difference between the central axis of the battery 10 and the temperature of the cylindrical porous body 15 was 3.5°C, as shown in Figure 7.

[0034] Figure 8 is an explanatory diagram of the temperature changes over time on the central axis and the outer circumference of battery 10. Figure 8 shows the temperature changes over time during 3C discharge at a height of 40 mm for battery 10, which is the middle of the seven batteries 10. Curve C3a (solid line) represents the temperature changes over time on the outer circumference, which is the coldest. Curve C3b (dashed line) represents the temperature changes over time on the central axis, which is the hottest. Curve C3c (dotted line) represents the temperature changes over time at the volume average within battery 10. As shown in curves C3a to C3c in Figure 8, all temperatures increase over time. As time passes, the temperature difference between the outer circumference and the central axis, as well as the volume average temperature, also increase. As shown in Figure 8, the temperature difference between the highest temperature (C3b) and the lowest temperature (C3a) immediately after discharge completion was 6.3°C.

[0035] Figure 9 is an explanatory diagram of the temperature distribution inside the battery 10 immediately after discharge is complete in the comparative example. Figure 9 shows the simulation results of the temperature distribution inside case 20 when the battery 10 is cooled by a liquid cooling method immediately after the battery 10 is discharged at 3C until the SOC corresponding to Figure 7(b) changes from 0.95 to 0.1. In the comparative example, 27°C cooling water is supplied into case 20 of the embodiment from vertically below to vertically above. In the temperature control system of the comparative example, cooling water is supplied at a mass flow rate of 0.01 kg / s without the cylindrical porous body 15 of the temperature control system 100 of this embodiment. In the temperature distribution of the comparative example shown in Figure 9, unlike the embodiment of steam heat transport, the temperature at a height of 70 mm (dotted line curve C4c) is higher than at a height of 40 mm (dashed line curve C4b). This is because the temperature of the cooling water supplied from vertically below rises vertically upward due to the heat from the battery 10. Note that the lowest temperature is at a height of 10 mm (solid curve C4a).

[0036] Comparing Figure 7(b) and Figure 9, the highest temperature on curve C4c (the dashed line in Figure 9), which represents the highest temperature in the comparative example, is higher than the highest temperature on curve C2b (the dashed line in Figure 7(b)), which represents the highest temperature in the embodiment. Furthermore, the temperature difference between the highest and lowest temperatures in the comparative example is greater than the temperature difference in the embodiment.

[0037] Figure 10 is an explanatory diagram illustrating the time course of the temperature along the central axis and the temperature on the outer circumference of the comparative example battery 10. Figure 10 shows the time course of the temperature during 3C discharge in the comparative example, which corresponds to Figure 8 of this embodiment. In addition to curves C5a to C5c, which correspond to curves C3a to C3c shown in Figure 8, Figure 10 shows the time course of the temperature difference between the cooling water supplied into the case 20 and the cooling water discharged from the case 20 as curve C5d (dotted line). Furthermore, Figure 10 shows the time course of the heat flow velocity from the tube wall of the battery 10 to the cooling water side as curve C5e (thin solid line). As shown by curve C5e representing the heat flow velocity, due to the low heat transfer coefficient of the cooling water, the heat flow velocity from the tube wall to the cooling water side is small, and the temperature of the battery 10 rises due to the difference in heat dissipation from the battery 10 to the cooling water side. As a result, the temperature rise from the start of discharge and the temperature difference between the maximum and minimum temperatures inside the battery 10 after discharge completion in the comparative example were 11.3°C, which is larger than the 6.3°C in the embodiment.

[0038] Figure 11 is an explanatory diagram illustrating the arrangement of multiple batteries 10 and their volume fraction and volume energy density ratio. Figure 11 shows, in bar graph form, the volume fraction (%) and volume energy density ratio that change depending on the arrangement of the multiple batteries 10 when the volume inside the case 20 is the same. The volume fraction is the ratio obtained by dividing the volume of the batteries occupied within the case 20 by the volume inside the case 20. The volume energy density ratio is the value obtained by dividing the total battery capacity (kWh) of the multiple batteries 10 by the sum of the volume of the multiple batteries 10 and the volume of the flow path through which the fluorocarbon medium 25 flows. The volume energy density ratio is calculated using the "prismatic" battery arrangement, described later, as a baseline of 100, and the values ​​for the "staggered arrangement" and "grid arrangement" are calculated.

[0039] Figure 11 shows the volume fraction and volume energy density ratio corresponding to three types: a "staggered arrangement" with hexagonal filling as in this embodiment; a "square" arrangement in which a flow channel for the fluorocarbon medium 25 is formed between multiple rectangular parallelepiped batteries; and a "grid arrangement" in which the central axes of multiple cylindrical batteries 10 are arranged in a grid along the X and Y axes. Above the bar graph in Figure 11 are schematic top views representing the "staggered arrangement," "square" arrangement, and "grid arrangement." In the "staggered arrangement" and "grid arrangement," the diameter of the battery 10 is 46 mm, and the thickness of the cylindrical porous body 15 is 1 mm. In the "square" arrangement, the width of the battery is 46 mm, and the thickness of the flow channel between the batteries is 10 mm. In all three arrangements, the height of the battery was 80 mm.

[0040] As shown in the bar graph in Figure 11, the volume ratio and volumetric energy density ratio of the "staggered arrangement" and "grid arrangement" are greater than those of the "square arrangement." This means that by adopting the "staggered arrangement" and "grid arrangement" of the battery 10, greater energy can be generated with a battery module of the same size. In particular, the "staggered arrangement" as in this embodiment shows an even greater improvement in volume ratio and volumetric energy density ratio compared to the "grid arrangement."

[0041] As described above, the temperature control system 100 of this embodiment comprises seven cylindrical batteries 10 arranged in close proximity to each other, a cylindrical porous body 15 covering each side of the seven batteries 10, a cooling unit 30 positioned vertically above the seven batteries 10, and a fluorocarbon-based medium 25 filled in a case 20. The fluorocarbon-based medium 25 changes between liquid and gaseous states depending on the heat generation state of the batteries 10. The cylindrical porous body 15 generates flow resistance for the liquid fluorocarbon-based medium 25 flowing along the sides of the batteries 10. Therefore, according to this embodiment, the batteries 10, which generate heat during charging and discharging, are cooled by vapor heat transport using the latent heat of the fluorocarbon-based medium 25 filled in the case 20. Each side of the cylindrical batteries 10 is covered by a cylindrical porous body 15 that makes it difficult for the liquid fluorocarbon-based medium 25 to flow vertically downward. Therefore, efficient heat exchange occurs between the liquid fluorocarbon-based medium 25 flowing inside the cylindrical porous body 15 and the surface of the batteries 10. The vaporized fluorocarbon medium 25 moves vertically upward through the space SP1 (Figure 2) within the case 20 and within the cylindrical porous body 15, where it is cooled and condensed by the cooling unit 30. The condensed liquid fluorocarbon medium 25 cools the battery 10 again. Compared to liquid cooling methods, the battery 10 is cooled more efficiently by vapor heat transport. As a result, the temperature difference between the maximum and minimum temperatures among the seven batteries 10 housed in the case 20 is suppressed. This allows for temperature control where the temperature difference among the seven batteries 10 is suppressed when the seven batteries arranged in the case 20 are used as a single module. Therefore, overcharging or over-discharging of batteries 10 with different capacity degradations within the case 20 is suppressed, and the deterioration of the battery life 10 is suppressed. Furthermore, in this embodiment, since the seven columnar batteries 10 are arranged adjacent to each other within the case 20, the volume ratio of the seven batteries 10 to the volume of the case 20 is improved. By improving the volume fraction, the energy density ratio, which is the energy of the battery 10 per unit volume, is improved. In other words, in the temperature control system 100 of this embodiment, the temperature difference generated between the batteries 10 is suppressed by uniform and high-power steam heat transport.

[0042] Furthermore, the cylindrical porous body 15 in this embodiment is made of a porous material. Therefore, the cylindrical porous body 15, made of a porous material, helps to maintain the liquid fluorocarbon-based medium 25 on the side of the battery 10 for a longer period of time. This allows for efficient cooling of the battery 10 using the latent heat of the liquid fluorocarbon-based medium 25.

[0043] <Second Embodiment> In the second embodiment of the temperature control system 100a, the shape of the upper busbar 40a and the shape of the bottom busbar 50a differ significantly from those of the first embodiment of the temperature control system 100. Therefore, in the second embodiment, the different shapes and configurations from the first embodiment will be described, and the description of the same configurations as the first embodiment will be omitted.

[0044] Figure 12 is a schematic top view of the temperature control system 100a of the second embodiment, viewed from vertically above the upper busbar 40a. Figure 12(a) shows the upper busbar 40a viewed from vertically above, with the batteries 10 and cylindrical porous body 15 located vertically below the upper busbar 40a indicated by dashed lines. Figure 12(b) shows the projected position of the hanging porous body 34, which is located vertically above the upper busbar 40a and spaced apart from that in Figure 12(a), indicated by a thick dashed line. The temperature control system 100a of the second embodiment does not have the connecting porous body 33 that is present in the cooling unit 30 of the first embodiment. Therefore, in the second embodiment, the hanging porous body 34 and the cylindrical porous body 15 covering each battery 10 are spaced apart. Instead of the connecting porous body 33, the upper busbar 40a has a regular hexagonal flat plate shape that extends horizontally and covers the upper surfaces of the seven batteries 10 as shown in Figure 12. As shown in Figure 12, the upper busbar 40a has a plurality of approximately equilateral triangular through holes 41 that penetrate vertically in the thickness direction. Some of the plurality of through holes 41 are formed in positions facing the upper surfaces of the batteries 10 and the cylindrical porous body 15. On the other hand, none of the through holes 41 are formed in positions that do not face the upper surfaces of the batteries 10 and the cylindrical porous body 15. In other words, the through holes 41 are not formed in positions facing the space SP1 (Figure 2) formed on the outer circumferential surface of the plurality of cylindrical porous bodies 15.

[0045] Because the hanging porous body 34 and the upper bus bar 40a are separated, the fluorocarbon-based medium 25, which has been condensed by the refrigerant flowing through the refrigerant channel 32, drips onto the upper bus bar 40a from the hanging porous body 34, which is located vertically above the upper bus bar 40a.

[0046] Figure 13 is a schematic cross-sectional view of the upper busbar 40a, the battery 10, and the cylindrical porous body 15. Figure 13 shows an enlarged schematic cross-section of a portion of the vertically upper side of one battery 10, the cylindrical porous body 15 covering the side of the battery 10, and a portion of the upper busbar 40a near the vertically upper side of the battery 10. As shown in Figure 13, a portion of the fluorocarbon-based medium 25 that drips from the hanging porous body 34 passes through the through-hole 41 of the upper busbar 40a, as indicated by arrow DR1, and flows along the top surface of the battery 10 into the cylindrical porous body 15. A portion of the fluorocarbon-based medium 25 vaporizes on the surface of the battery 10 due to the heat generated by the battery 10.

[0047] Figure 14 is a schematic perspective view of the bottom busbar 50a and the liquid receiving section 80 in the second embodiment. As shown in Figure 14, the temperature control system 100a of the second embodiment includes a liquid receiving section 80 positioned vertically below seven batteries 10, a bottom busbar 50a positioned vertically below the liquid receiving section 80, a heating section 60 positioned vertically below the bottom busbar 50a at spaced intervals, and a plurality of insulating supports 70 positioned vertically between the heating section 60 and the bottom busbar 50.

[0048] The temperature control system 100a of the second embodiment differs from the temperature control system 100 of the first embodiment in that it includes a liquid receiving section 80 and has a different shape for the bottom busbar 50a. As shown in Figure 14, the liquid receiving section 80 has a shape in which the bottoms of seven cylinders, each with an open top, are connected, and the tops of the cylinders are positioned vertically below each of the seven batteries 10. The liquid receiving section 80 has a bottom surface 81 with a surface parallel to the horizontal direction and a wall portion 82 extending vertically upward from the bottom surface 81. The upper surface of the bottom surface 81 facing the batteries 10 is electrically connected to the vertically downward terminals of each of the seven batteries 10. The inner circumferential surface of the wall portion 82 is in contact with the outer circumferential surface of the cylindrical porous body 15 that covers the sides of each battery 10. Therefore, the fluorocarbon-based medium 25 liquid that drips down the cylindrical porous body 15 is stored in the liquid receiving section 80. Furthermore, some of the liquid fluorocarbon-based medium 25 that passes through the space SP1 (Figure 2) formed between the cylindrical porous bodies 15 of adjacent batteries 10 moves vertically downward within the case 20, below the liquid receiving section 80, and reaches the upper surface of the heating section 60.

[0049] Figure 15 is a schematic bottom view of the bottom busbar 50a of the second embodiment. In addition to the bottom busbar 50a, Figure 15 shows the case 20, the batteries 10 and cylindrical porous body 15 located vertically above the bottom busbar 50a are shown by dashed lines, and the insulating support 70 located vertically below the bottom busbar 50a is also shown by dashed lines. As shown in Figure 15, the bottom busbar 50a, viewed from vertically below, has a shape in which flat plates of a predetermined width are combined, connecting the central axes of two or more batteries 10 that are aligned in a straight line out of the seven batteries 10. The angles formed by the two non-parallel sets of flat plates are both 60 degrees.

[0050] As described above, in the temperature control system 100a of the second embodiment, the cooling unit 30 includes a plurality of flow path forming units 31 that form a refrigerant flow path 32 through which a refrigerant that cools the inside of the case 20 flows, and a hanging porous body (hanging part) 34 that covers the outer wall of the side surface of the flow path forming unit 31. As shown in Figure 12, the upper busbar 40a covers the upper surface of the seven batteries 10 and has a flat plate shape that extends horizontally. In the second embodiment, the upper busbar 40a, which is electrically connected to the terminals on the vertically upper side of each battery 10, generates heat when current flows through it. In particular, during high-rate charging and discharging such as 3C, the upper busbar 40a becomes hot, and the area of ​​the upper busbar 40a that is connected to the battery terminals becomes even hotter. In the second embodiment, since the upper busbar 40a has a flat plate shape that extends horizontally, much of the liquid fluorocarbon medium 25 that drips vertically downward from the cooling unit 30 comes into contact with the upper busbar 40a, and the upper busbar 40a is cooled. Furthermore, since the hanging porous body 34 is positioned at a distance from the upper bus bar 40a, leakage current between the hanging porous body 34 and the flow channel forming section 31 via the hanging porous body 34 and the upper bus bar 40a is suppressed. On the other hand, the hanging porous body 34 is located vertically below the lower end of the outer wall of the flow channel forming section 31. Therefore, the fluorocarbon-based medium 25, which has been cooled and liquefied by the refrigerant flowing through the refrigerant flow channel 32, is quickly dripped vertically downward through the hanging porous body 34. As a result, the upper bus bar 40a and the battery 10 are efficiently cooled by heat vapor transport by the cooling section 30.

[0051] Furthermore, as shown in Figure 12, the upper busbar 40a of the second embodiment has a plurality of approximately equilateral triangular through-holes 41 that penetrate in the vertical direction, which is the thickness direction. Some of the plurality of through-holes 41 are formed in positions facing the upper surface of the battery 10 and the upper surface of the cylindrical porous body 15. Therefore, in the second embodiment, some of the liquid fluorocarbon medium 25 dripping from the cooling unit 30 is supplied to the cylindrical porous body 15 without contacting the upper busbar 40a. As a result, the area near the terminals of the battery 10, which becomes particularly hot in the upper busbar 40a, is cooled, suppressing localized overheating, and the battery 10 is also cooled by the liquid fluorocarbon medium 25 supplied to the cylindrical porous body 15. In addition, the through-holes 41 are not formed in positions facing the space SP1 (Figure 2) formed on the outer circumferential surface of the plurality of cylindrical porous bodies 15. Therefore, the liquid fluorocarbon medium 25 does not flow directly into the space SP1 through the through-holes 41. As a result, the liquid fluorocarbon medium 25 flows into the top surface of the battery 10 or the cylindrical porous body 15, thereby efficiently cooling the battery 10.

[0052] Furthermore, the temperature control system 100a of the second embodiment, as shown in Figure 14, includes a liquid receiving section 80 positioned vertically below the seven batteries 10, and a bottom bus bar 50a positioned vertically below the liquid receiving section 80. The upper surface of the bottom surface 81 of the liquid receiving section 80 is electrically connected to the vertically downward terminals of each of the seven batteries 10. The liquid receiving section 80 stores the liquid fluorocarbon medium 25 that has dripped down the cylindrical porous body 15. In the second embodiment, the current flowing through the batteries 10 flows between the batteries 10 and the bottom bus bar 50a via the liquid receiving section 80. The liquid receiving section 80 and the bottom bus bar 50a, like the upper bus bar 40a, generate heat when current flows through them. The liquid fluorocarbon medium 25 that has flowed vertically downward from the batteries 10 is stored in the liquid receiving section 80 and used to cool the liquid receiving section 80 and the bottom bus bar 50a. In particular, the vertically downward surface of the battery 10 is in direct contact with the liquid fluorocarbon medium 25, resulting in a high heat flow rate and thus a form of boiling heat transfer. Therefore, even with a small heat transfer area, the high heat flow rate enables cooling of the battery 10 and the bottom busbar 50a. In addition, the vaporization of the liquid fluorocarbon medium 25 flowing vertically downward increases the flow rate of the fluorocarbon medium 25 circulating within the case 20, suppressing dry-out, which is likely to occur on the vertically downward side of the battery 10.

[0053] <Third Embodiment> Figures 16 and 17 are explanatory diagrams of the bottom busbar 50b of the third embodiment. The third embodiment differs from the second embodiment in that there is no liquid receiving portion 80, and the bottom busbar 50b has a shape that functions as the liquid receiving portion 80. Figure 16 shows a schematic top view of the bottom busbar 50b of the third embodiment. Figure 17 shows a schematic cross-sectional view of the bottom busbar 50b.

[0054] As shown in Figure 17, the bottom busbar 50b has a flat bottom surface 52 located vertically downward and a battery connection portion 53 located vertically upward of the bottom surface 52. When viewed from the vertical direction, the bottom surface 52 has a regular hexagonal shape smaller than the cross-sectional shape of the case 20. The battery connection portion 53 has the same shape as the bottom busbar 50a of the second embodiment, as shown in Figure 16. In the bottom busbar 50b, liquid fluorocarbon medium 25 is temporarily stored in the space on the upper side of the bottom surface 52 where the battery connection portion 53 does not exist. Therefore, this space functions as a configuration equivalent to the liquid receiving portion 80 of the second embodiment. Note that in Figure 16, as in Figure 15, the case 20 is shown, the battery 10 and cylindrical porous body 15 located vertically upward of the bottom busbar 50b are shown by dashed lines, and the insulating support 70 located vertically downward of the bottom busbar 50b is also shown by dashed lines.

[0055] In the third embodiment, the bottom busbar 50b has a plurality of through holes 51 that penetrate the bottom surface 52 and the battery connection portion 53 in the thickness direction (vertical direction). The through holes 51 are formed in positions that include a part of the outer circumference of the cylindrical porous body 15. The schematic cross-section shown in Figure 17 is a cross-section along the central axis parallel to the vertical direction of the through holes 51. Because the through holes 51 are formed in a position vertically below the cylindrical porous body 15, a portion of the liquid fluorocarbon medium 25 that has traveled along the cylindrical porous body 15 to the upper surface of the battery connection portion 53 moves through the through holes 51 to the space SP3 between the upper surface of the heating portion 60 and the lower surface of the bottom busbar 50b. The space SP3 is a space that has the same height as the insulating support 70 which is positioned between the bottom surface 52 and the heating portion 60. The fluorocarbon medium 25 that has moved into the space SP3, i.e., to the surface of the heating portion 60, is vaporized by heating by the heating portion 60.

[0056] <Fourth Embodiment> The temperature control system 100b of the fourth embodiment differs from the temperature control system 100a of the second embodiment in that it includes two terminals 85 and 86 connected to the bottom busbar 50a, a temperature sensor (temperature acquisition unit) 95 for detecting the temperature of the battery 10, and a control unit (switching unit) 90 for controlling the connection of the temperature control system 100b to an external load and one of the two terminals 85 and 86. In the fourth embodiment, the control unit 90 switches the terminal connected to the external load between two first terminals 85 and second terminals 86 for extracting power supplied from the seven batteries 10, according to the temperature of the battery 10 detected by the temperature sensor 95. In the fourth embodiment, the electrical resistance of the second terminal 86 is set lower than that of the first terminal 85. Therefore, the amount of heat generated when the first terminal 85 is connected to the external load is greater than the amount of heat generated when the second terminal 86 is connected to the external load.

[0057] Figure 18 is a schematic perspective view of the bottom busbar 50a of the fourth embodiment. Figure 18 shows schematic perspective views of the bottom busbar 50a, six insulating supports 70 supporting the bottom busbar 50a, a first terminal 85, and a second terminal 86. The first terminal 85 of the fourth embodiment is positioned in place of the central insulating support 70 among the seven insulating supports 70 of the second embodiment. The first terminal 85 is made of a conductive material. The second terminal 86 is positioned at the outer peripheral end of the bottom busbar 50a, as shown in Figure 18. The second terminal 86 is made of a conductive material that has lower resistance than the first terminal 85.

[0058] Figure 19 is an explanatory diagram of the connection switching between the first terminal 85 and the second terminal 86 in the fourth embodiment. Figure 19 shows a schematic cross-sectional view of the temperature control system 100b of the fourth embodiment and a block diagram of the control by the control unit 90. Figure 19 shows a cross-section of a part of the vertically downward side of the temperature control system 100b. The temperature control system 100b comprises a liquid receiving section 80b, a temperature sensor 95 that detects the temperature of the battery 10 located in the center of the seven batteries 10, and a control unit 90 that switches the connection destination of the external terminal, which is a load, between the first terminal 85 and the second terminal 86 according to the temperature detected by the temperature sensor 95.

[0059] Unlike the liquid receiving section 80 of the second embodiment, the liquid receiving section 80b of the fourth embodiment has two types of wall sections 82 and 83 with different heights. The height of the wall section 83, which is located on the outer circumference of the cylindrical porous body 15 covering the side surface of the central battery 10 among the seven batteries 10, is lower than the height of the wall sections 82, which are located on the outer circumference of the cylindrical porous body 15 of the other batteries 10. Therefore, of the liquid fluorocarbon medium 25 that flows vertically downward from the seven batteries 10, the fluorocarbon medium 25 that flows vertically downward from the central battery 10 is more likely to flow between the lower surface of the bottom busbar 50a and the upper surface of the heating section 60, along arrow DR2. Although not shown in detail in Figure 19, the bottom surface 81b of the liquid receiving section 80b is inclined vertically downward from the outer circumference towards the center. Therefore, the liquid fluorocarbon medium 25 stored in the liquid receiving section 80b tends to accumulate in the center. In other words, in the liquid receiving section 80b, the stored fluorocarbon-based medium 25 is more likely to move to the upper surface of the heating section 60 on the vertically downward side of the liquid receiving section 80b in the central part than in the outer periphery.

[0060] The control unit 90 connects the second terminal 86 to the load when the battery 10 is in a steady state. The control unit 90 connects the first terminal 85 to the load when the battery 10 is under a high load. In the fourth embodiment, the control unit 90 determines that the load is high when the temperature detected by the temperature sensor 95 is high (for example, 35°C) or higher, and determines that the load is steady when the detected temperature is below the threshold.

[0061] As described above, in the temperature control system 100b of the fourth embodiment, the control unit 90 connects the second terminal 86, which has low electrical resistance, to an external load when the battery 10 is in a steady state, and connects the first terminal 85, which has high electrical resistance, to an external load when the battery 10 is under high load. In this embodiment, the terminal on the vertically lower side of the battery 10 is switched between the first terminal 85 and the second terminal 86, which have different electrical resistances, so that the amount of heat generated by terminals 85 and 86 differs depending on which terminals 85 and 86 are connected during charging and discharging of the battery 10. Under high load conditions, the flow rate of the fluorocarbon-based medium 25 circulating in the case 20 may be insufficient compared to the steady state, and the cooling of the battery 10, etc., by steam heat transport may not be sufficiently performed. In the fourth embodiment, when under high load conditions, the battery 10 is connected to the high-resistance first terminal 85, and the high amount of heat generated by the first terminal 85 is used to compensate for the insufficient amount of circulating fluorocarbon-based medium 25. As a result, the output of steam heat transport under high load conditions is improved. On the other hand, during steady-state operation with a lower load than during high-load operation, power loss at the second terminal 86 is reduced by connecting an external load to the second terminal 86.

[0062] Furthermore, in the liquid receiving section 80b of the fourth embodiment, the stored liquid fluorocarbon medium 25 is more likely to move to the upper surface of the heating section 60 vertically below the liquid receiving section 80b in the central part than on the outer periphery. The first terminal 85 is positioned in the center where the liquid fluorocarbon medium 25 tends to accumulate, and the second terminal 86 is positioned on the outer periphery. In the fourth embodiment, the liquid fluorocarbon medium 25 stored in the liquid receiving section 80b tends to accumulate on the upper surface of the heating section 60, which is vertically below the central part. The first terminal 85, which has high resistance, is positioned in the central part where the fluorocarbon medium 25 tends to accumulate. Therefore, vaporization of the fluorocarbon medium 25 due to the heat generated by the first terminal 85 under high load conditions is efficiently performed. As a result, the output of steam heat transport under high load conditions is further improved.

[0063] Furthermore, in the fourth embodiment, the control unit 90 determines that a high load is occurring when the temperature detected by the temperature sensor 95 is above a threshold, and determines that a steady state is occurring when the detected temperature is below the threshold. In other words, in the fourth embodiment, the steady state and high load of the battery 10 are determined by the temperature of the battery 10. When the temperature of the battery 10 is high, it means that the battery 10 and other components require more cooling. The high load and steady state are easily determined by the temperature of the battery 10, and the output of steam heat transport utilizing the heat generated by the first terminal 85 is increased when necessary.

[0064] <Modified examples of embodiments> The present invention is not limited to the embodiments described above, and can be implemented in various forms without departing from its spirit. For example, the following modifications are possible. Furthermore, in the above embodiments, some of the configurations implemented by hardware may be replaced with software, and conversely, some of the configurations implemented by software may be replaced with hardware.

[0065] <Example 1> The temperature control systems 100, 100a, and 100b of the first to fourth embodiments described above are examples of systems for cooling multiple columnarly arranged batteries 10. The temperature control system (temperature control device) is modifiable within the range of comprising multiple columnar batteries 10 arranged horizontally within a case 20, a cooling unit 30 arranged vertically above the batteries 10, and a heat transfer medium for steam heat transport filled within the case 20. The number of columnar batteries 10 arranged within the case 20 may be less than 7 or 8 or more. The columnar batteries 10 may have a prismatic shape. The multiple batteries 10 arranged within the case 20 may be arranged in a grid or the like, rather than in a staggered arrangement with hexagonal filling as shown in Figure 11. The arrangement is preferably one that improves the volume fraction and volumetric energy density.

[0066] In the cooling unit 30, refrigerant is supplied to multiple refrigerant channels 32, but any well-known cooling device can be applied as long as it is capable of cooling the fluorocarbon medium 25 inside the case 20. The boiling point of the heat transfer medium that performs vapor heat transport can be set appropriately according to the target control temperature of the battery 10. A heat transfer medium other than the fluorocarbon medium 25 may be used. The cooling unit 30 of the first embodiment does not have to include a connected porous body 33 as in the second embodiment. The hanging porous body 34 of the cooling unit 30 does not necessarily have to extend below the vertical lower end of the channel forming section 31, and may only cover the side surface of the channel forming section 31. The temperature control systems 100, 100a, and 100b do not have to include a heating unit 60 positioned vertically below. The shape and number of the multiple insulating supports 70 positioned between the bottom busbar 50 and the heating unit 60 shown in Figure 14 can be changed.

[0067] <Modification 2> The shapes of the upper busbars 40, 40a and the lower busbars 50, 50a, 50b are deformable within the range of electrical connection to the vertically upper or vertically lower terminals of the multiple batteries 10. The shape, position, and number of through holes 41 formed in the upper busbar 40a and the through holes 51 formed in the lower busbar 50b of the second embodiment are deformable. The position of the hanging porous body 34 relative to the upper busbar 40a is also deformable.

[0068] The shape of the liquid receiving portions 80 and 80b can be deformed within a range that allows for the storage of the fluorocarbon-based medium 25 liquid that flows vertically downward from the battery 10. The liquid receiving portion 80 does not have to have a wall portion 82 that matches the side surface of the cylindrical porous body 15 as shown in Figure 14. For example, the liquid receiving portion 80 may have multiple through holes formed on a surface that has the same shape as the cross section along the horizontal direction inside the case 20. The bottom busbar 50b of the third embodiment does not have to have through holes 51 formed as shown in Figure 17.

[0069] <Variation 3> In the fourth embodiment, the first terminal 85 is positioned in the center of the bottom busbar 50a, and the second terminal 86 is positioned on the outer periphery, but the positions of the first terminal 85 and the second terminal 86 are deformable. In addition, there is a third terminal having a higher electrical resistance than the first terminal 85 and the second terminal 86, and the control unit 90 may divide the temperature of the battery 10 into three temperature zones and switch the terminal connected to the external load.

[0070] The control unit 90 determined high load and steady state by comparing the temperature of the battery 10 with a threshold value, but high load and steady state may be determined by other methods. For example, high load and steady state may be determined according to the power required by the battery 10. Also, when the battery 10 is used as a power source for an automobile, high load and steady state may be determined according to the speed of the automobile.

[0071] In the liquid receiving section 80b of the fourth embodiment, the wall portion 83 covering the outer circumference of the cylindrical porous body 15 of the central battery 10 was lower in height than the wall portions 82 covering the outer circumferences of the other cylindrical porous bodies 15, and the bottom surface 81 was inclined vertically downward from the outer circumference to the center. However, as in the second embodiment, the height of the wall portion 83 may be the same as the height of the wall portion 82. Also, the bottom surface 81b does not have to be inclined. To facilitate the movement of the fluorocarbon-based medium 25 liquid stored in the liquid receiving section 80b towards the vertically downward side of the liquid receiving section 80b in the central part, for example, more through holes 51 (Figure 17) may be formed in the central part.

[0072] The embodiments of this specification have been described above based on the embodiments and modifications described above. The embodiments described above are for the purpose of facilitating understanding of this specification and do not limit it. This specification may be modified and improved without departing from its spirit and the scope of the claims, and equivalents thereof are included in this specification. Furthermore, any technical features that are not described as essential in this specification may be deleted as appropriate.

[0073] The present invention can also be realized in the following forms. [Application Example 1] A temperature control device, Multiple columnar batteries arranged in close proximity to each other, A housing section containing the aforementioned multiple batteries, A heat transfer medium, which is filled in the aforementioned containment section and changes between gas and liquid depending on the temperature, A covering portion covers each of the sides of the plurality of batteries and generates flow resistance of the heat transfer medium, which is a liquid flowing along the side, A cooling unit is positioned vertically above the plurality of batteries within the housing and cools the heat transfer medium, Equipped with, The plurality of batteries are in contact with adjacent batteries, at least in part, via the covering portion. A temperature control device in which the heat transfer medium is condensed and liquefied by the cooling unit and vaporized by the heat of the plurality of batteries. [Application Example 2] A temperature control device as described in Application Example 1, The covering portion is formed of a porous material, and the device is a temperature control device. [Application Example 3] A temperature control device as described in Application Example 1 or Application Example 2, further, The upper busbar is positioned vertically above the plurality of batteries in the housing and vertically below the cooling section, is electrically connected to the terminals on one side of each of the plurality of batteries, and has a flat plate shape extending horizontally. The cooling unit is A flow path forming section that extends horizontally and forms multiple refrigerant flow paths through which refrigerant flows, A hanging portion, formed of a porous material, covers at least a portion of the outer wall of the channel forming section, extends vertically downward from the lower end of the outer wall of the channel forming section in a range spaced apart from the upper busbar, and comprises a portion that covers at least a part of the outer wall of the channel forming section and extends vertically downward from the lower end of the outer wall of the channel forming section. A temperature control device having the following features. [Application Example 4] A temperature control device described in any one of the application examples 1 to 3, The upper busbar has through holes formed in at least a portion of the position opposite the covering portion, The cooling unit is a temperature control device positioned vertically above the upper busbar, spaced apart from the upper busbar. [Application Example 5] A temperature control device described in any one of Application Examples 1 to 4, further, A liquid receiving section for storing the heat transfer medium, located vertically below the plurality of batteries within the housing section, and electrically connected to the terminals on the other side of each of the plurality of batteries, A bottom busbar is positioned vertically below the liquid receiving section and electrically connected to the liquid receiving section, A temperature control device equipped with the following features. [Application Example 6] A temperature control device described in any one of Application Examples 1 to 5, further, A first terminal electrically connected to the bottom busbar for extracting power supplied from the multiple batteries, A second terminal electrically connected to the bottom busbar and for extracting power supplied from the plurality of batteries, the second terminal having an electrical resistance lower than the electrical resistance of the first terminal, When extracting power supplied from the aforementioned multiple batteries, a switching unit is provided to switch the connection to the second terminal during steady-state operation and to the first terminal during high-load operation. A temperature control device equipped with the following features. [Application Example 7] A temperature control device described in any one of the application examples 1 to 6, The first terminal is located in the center of the bottom busbar. The second terminal is located on the outer circumference side of the bottom busbar. A temperature control device in which, in the liquid receiving section, the heat transfer medium of the liquid stored in the liquid receiving section is more likely to move vertically downward from the liquid receiving section in the central part than on the outer periphery. [Application Example 8] A temperature control device described in any one of Application Examples 1 to 7, further, It is equipped with a temperature acquisition unit that acquires the temperature of the battery, The switching unit determines that the battery is in a steady state when the acquired battery temperature is below a threshold, and determines that it is in a high-load state when the battery temperature is above a threshold. [Explanation of symbols]

[0074] 10...Battery 15…Cylindrical porous body (coating part) 20… Case (storage compartment) 25...Fluorocarbon-based fluids (heat transfer fluids) 30…Cooling section 31... Flow channel forming section 32… Refrigerant flow path 33… Linked porous body 34...Drooping porous body (hanging part) 40,40a... Upper busbar 41…Through-hole for upper busbar 50, 50a, 50b...Bottom busbar 51…Through-hole for bottom busbar 52…Bottom part 53...Battery connection 60…Heating part 70…Insulating support 80, 80b... Liquid receiving section 81, 81b... Bottom surface of the liquid receiving section 82, 83... Wall section of the liquid receiving part 85...1st terminal 86...2nd terminal 90...Control unit (switching unit) 95...Temperature sensor (temperature acquisition unit) 100, 100a, 100b… Temperature control system (temperature control device) PL...Flat plate LB... Rib SP1~SP3…Space

Claims

1. A temperature control device, Multiple columnar batteries arranged in close proximity to each other, A housing section containing the aforementioned multiple batteries, A heat transfer medium, which is filled into the aforementioned containment section and changes between gas and liquid depending on the temperature, A covering portion that covers each side of the plurality of batteries and generates flow resistance of the liquid heat transfer medium flowing along the side, A cooling unit is positioned vertically above the plurality of batteries within the housing and cools the heat transfer medium, Equipped with, The plurality of batteries are in contact with adjacent batteries, at least in part, via the covering portion. A temperature control device in which the heat transfer medium is condensed and liquefied by the cooling unit and vaporized by the heat of the plurality of batteries.

2. A temperature control device according to claim 1, The aforementioned covering portion is formed of a porous material, and is a temperature control device.

3. A temperature control device according to claim 1, further, The upper busbar is positioned vertically above the plurality of batteries in the housing and vertically below the cooling section, is electrically connected to the terminals on one side of each of the plurality of batteries, and has a flat plate shape extending horizontally. The cooling unit is A flow path forming section that extends horizontally and forms multiple refrigerant flow paths through which refrigerant flows, A hanging portion, formed of a porous material, covers at least a portion of the outer wall of the channel forming section, extends vertically downward from the lower end of the outer wall of the channel forming section in a range spaced apart from the upper busbar, and comprises a portion that covers at least a part of the outer wall of the channel forming section and extends vertically downward from the lower end of the outer wall of the channel forming section. A temperature control device having the following features.

4. A temperature control device according to claim 3, The upper busbar has through holes formed in at least a portion of the position opposite the covering portion, The cooling unit is a temperature control device positioned vertically above the upper busbar, spaced apart from the upper busbar.

5. A temperature control device according to any one of claims 1 to 4, further comprising: A liquid receiving section for storing the heat transfer medium, located vertically below the plurality of batteries within the housing section, and electrically connected to the terminals on the other side of each of the plurality of batteries, A bottom busbar is positioned vertically below the liquid receiving section and electrically connected to the liquid receiving section, A temperature control device equipped with the following features.

6. A temperature control device according to claim 5, further, A first terminal electrically connected to the bottom busbar for extracting power supplied from the multiple batteries, A second terminal electrically connected to the bottom busbar and for extracting power supplied from the plurality of batteries, the second terminal having an electrical resistance lower than the electrical resistance of the first terminal, When extracting power supplied from the aforementioned multiple batteries, a switching unit is provided to switch the connection to the second terminal during steady-state operation and to the first terminal during high-load operation. A temperature control device equipped with the following features.

7. A temperature control device according to claim 6, The first terminal is located in the center of the bottom busbar. The second terminal is located on the outer circumference side of the bottom busbar. A temperature control device in which, in the liquid receiving section, the heat transfer medium of the liquid stored in the liquid receiving section is more likely to move vertically downward from the liquid receiving section in the central part than on the outer periphery.

8. A temperature control device according to claim 6, further, It is equipped with a temperature acquisition unit that acquires the temperature of the battery, The switching unit determines that the battery is in a steady state when the acquired battery temperature is below a threshold, and determines that it is in a high-load state when the battery temperature is above a threshold.

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