JP2019087372A - Battery cooling system - Google Patents

Abstract

To provide a battery cooling system configured to simply adjust currents flowing in batteries.SOLUTION: A system for cooling batteries with cooling air includes: a first battery arranged in a first cooling path; a second battery arranged in a second cooling path different from the first cooling path; and a regulator valve which controls cooling air flowing in the first cooling path and cooling air flowing in the second cooling path, on the basis of states of the first battery and the second battery. At least a part of first electrical wiring electrically connected to the first battery or at least a part of a heat pipe thermally connected to the first electrical wiring is disposed in the second cooling path. At least a part of second electrical wiring electrically connected to the second battery or at least a part of a heat pipe thermally connected to the second electrical wiring is disposed in the first cooling path.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a battery cooling system that cools a battery by applying cooling air.

  In a battery unit in which a plurality of batteries are connected in parallel, it is necessary to restore the current balance when the current balance of the batteries is broken due to the individual difference of the batteries or the variation of the resistance value due to the time change. As a method of returning the current balance, for example, Patent Document 1 discloses a system for adjusting the temperature of one of the batteries connected in parallel when the current balance of the two batteries is broken.

JP, 2017-073889, A

  As well known, an electrical wiring made of a metal material or the like for electrically connecting a battery has a temperature characteristic that the resistance value is increased when the temperature is high, and the resistance value is decreased when the temperature is low. On the other hand, the internal resistance value of the battery exhibits a temperature characteristic reverse to the resistance value of the electrical wiring, the resistance value decreases when the battery temperature is high, and the resistance value increases when the battery temperature is low.

  Therefore, for example, as shown in FIG. 5, in the battery cooling system 100 having a structure in which two batteries 110 and 120 connected in parallel are installed in the duct 300 for cooling, the battery 120 is unbalanced. If the battery 110 in which the current flows more is cooled together with the electrical wiring 210d, the internal resistance value of the battery 110 increases but the resistance value of the electrical wiring 210d decreases. Therefore, in such a cooling method, there is a problem that the change in the total resistance value due to the internal resistance value of the battery 110 and the resistance value of the electrical wiring 210d becomes small, and it is difficult to balance the current flowing in each battery.

  This invention is made in view of the said subject, and it aims at providing the battery cooling system which can carry out balance adjustment of the electric current sent through each battery easily.

  In order to solve the above problems, one aspect of the present invention is a system for applying cooling air to cool a battery, comprising: a first battery installed in a first cooling path; and a first cooling path And a second cooling path to be circulated in the first cooling path based on the second battery installed in the second cooling path different from the second cooling path and the states of the first battery and the second cell. A regulating valve for controlling a cooling air to be circulated, and a heat pipe thermally connected to at least a part of the first electric wiring electrically connected to the first battery or the first electric wiring Heat disposed at least partially in the second cooling path and thermally connected to at least a portion of the second electrical wiring electrically connected to the second battery or the second electrical wiring At least a part of the pipe is disposed in the first cooling path.

  In the system of this aspect, at least a portion of the first electrical wiring or the like electrically connected to the first battery installed in the first cooling path is disposed in the second cooling path, In addition, a cross wiring structure is employed in which at least a portion of a second electrical wiring or the like electrically connected to a second battery installed in the second cooling path is disposed in the first cooling path. ing.

  With such a cross wiring structure, when the current flowing in one battery is larger than the current flowing in the other battery and the current balance is broken, the control valve is controlled to cool the cooling air only in one cooling path. It is possible to simultaneously execute the temperature decrease of one battery (the increase of the internal resistance value) and the temperature decrease of the electric wiring of the other battery (the decrease of the wiring resistance value) by only feeding the battery. As a result, one battery changes in the current decreasing direction and the other battery changes in the current increasing direction, so that the current flowing in each battery can be controlled in a balanced direction.

  According to the battery cooling system of the present invention, it is possible to easily carry out balance adjustment of the current supplied to each battery.

Principal part transparent view explaining schematic structural example of the battery cooling system which concerns on this embodiment A flowchart showing a procedure of current balance processing performed by the battery cooling system according to the present embodiment A diagram specifically explaining an example in which current balance processing is performed Principal part transparent view explaining schematic structural example of the other battery cooling system which concerns on embodiment Principal part transparent view explaining schematic structural example of the other battery cooling system which concerns on embodiment Principal part transparent view explaining schematic structural example of the other battery cooling system which concerns on embodiment Principal part perspective view explaining the example of outline composition of the conventional battery cooling system

[Overview]
In the battery cooling system of the present invention, a portion of the first electrical wiring connected to the first battery installed in the first cooling path is disposed in the second cooling path, and A portion of the second electrical wiring connected to the second battery installed in the cooling path is disposed in the first cooling path. With this structure, when the current balance is broken, it is possible to simultaneously execute the temperature decrease of one battery and the temperature decrease of the electrical wiring of the other battery only by feeding the cooling air only to one of the cooling paths. Therefore, since one battery changes in the current decreasing direction and the other battery changes in the current increasing direction, it is possible to control the current flowing in each battery in a balanced direction.

[Constitution]
FIG. 1 is a perspective view of an essential part for explaining a schematic configuration example of a battery cooling system 1 according to an embodiment of the present invention. The battery cooling system 1 according to the present embodiment in FIG. 1 includes a first battery 11 and a second battery 12 connected in parallel, a duct 30, a regulating valve 40, and a fan 50.

  The battery cooling system 1 of the present invention may include a plurality of sets of the first battery 11 and the second battery 12 connected in parallel in series and / or in parallel. Even when a plurality of sets are provided in series and / or in parallel, the advantageous effects of the present invention can be obtained by configuring and controlling the first battery 11 and the second battery 12 in each set as described below. Can be played.

  The duct 30 is a tube for battery cooling which circulates a cooling air for cooling one or both of the first battery 11 and the second battery 12. The duct 30 has a structure in which one cooling path is branched into a first cooling path 31 and a second cooling path 32 in a section from the upstream position U to the downstream position D.

  The fan 50 is a device that is provided at a predetermined position in the duct 30 and can generate cooling air that circulates in the duct 30 by rotating. FIG. 1 shows an example in which the fan 50 is provided in front of the upstream position U where the duct 30 branches into the first cooling path 31 and the second cooling path 32.

  The first battery 11 and the second battery 12 are, for example, chargeable and dischargeable power storage elements such as lead storage batteries and lithium ion batteries. The first battery 11 is installed in the first cooling path 31 of the duct 30. The second battery 12 is installed in the second cooling path 32 of the duct 30. The first battery 11 and the second battery 12 may be configured by a single battery, or may be configured by an assembled battery in which a plurality of single batteries are connected in series.

  The first battery 11 is electrically connected to a predetermined device (not shown) that utilizes the power of its own battery via first electric wires 21 u and 21 d made of a conductive material such as copper, for example. ing. At least a portion of the first electric wires 21 u and 21 d is disposed in the second cooling path 32. In FIG. 1, a part of the first electric wiring 21 d drawn to the downstream position D side where the first cooling path 31 and the second cooling path 32 merge is disposed in the second cooling path 32. An example is shown. In addition to this, a part of the first electric wiring 21 u drawn to the upstream position U side may be disposed in the second cooling path 32.

  Second battery 12 is electrically connected to a predetermined device (not shown) that utilizes the power of its own battery via second electric wires 22u and 22d made of a conductive material such as copper, for example. ing. At least a part of the second electric wires 22 u and 22 d is disposed in the first cooling path 31. In FIG. 1, a part of the second electric wiring 22 d drawn to the downstream position D side where the first cooling path 31 and the second cooling path 32 merge is disposed in the first cooling path 31. An example is shown. Apart from this, a part of the second electric wiring 22 u drawn to the upstream position U side may be disposed in the first cooling path 31.

  The adjustment valve 40 is provided at an upstream position U where the duct 30 branches into the first cooling path 31 and the second cooling path 32. The adjusting valve 40 is controlled based on the state of the first battery 11 and the second battery 12 by a predetermined control device (not shown), and the cooling air and the second The cooling air to be circulated through the cooling path 32 is adjusted. The states of the first battery 11 and the second battery 12 indicate, for example, whether or not the current flowing to the first battery 11 and the current flowing to the second battery 12 maintain a predetermined current balance. I say the state. The control of the adjusting valve 40 will be described in detail below.

[control]
FIG. 2 is a flowchart showing the procedure of the current balance process performed by the battery cooling system 1 according to the present embodiment. This current balance process is repeatedly performed while the battery cooling system 1 is in operation.

  Step S21: It is determined whether the difference between the first current flowing to the first battery 11 and the second current flowing to the second battery 12 exceeds a predetermined threshold. The threshold value is a reference value for determining whether or not current balance processing should be performed, and can be appropriately determined according to the specifications required for the battery cooling system 1 or the like. If the difference between the two currents exceeds the threshold (S21, Yes), the process proceeds to step S22. On the other hand, if the difference between the two currents does not exceed the threshold (S21, No), the process proceeds to step S25.

  Step S22: It is determined which of the first current flowing to the first battery 11 and the second current flowing to the second battery 12 is larger. If the first current is large (S22, Yes), the process proceeds to step S23. If the second current is large (S22, No), the process proceeds to step S24.

  Step S23: The position of the regulating valve 40 is controlled to close the second cooling path 32. As a result, the cooling air is sent only to the first cooling path 31. When the position of the adjustment valve 40 is controlled, the process returns to step S21.

  Step S24: The position of the control valve 40 is controlled to close the first cooling path 31. As a result, the cooling air is sent only to the second cooling path 32. When the position of the adjustment valve 40 is controlled, the process returns to step S21.

  Step S25: The adjusting valve 40 is controlled to the neutral position. In this neutral position, cooling air is sent to both the first cooling path 31 and the second cooling path 32. When the position of the adjustment valve 40 is controlled, the process returns to step S21.

  FIG. 3 is a diagram specifically illustrating an example in which the current balance process is performed in the battery cooling system 1. FIG. 3 exemplifies the case where the current flowing to the first battery 11 is larger than the current flowing to the second battery 12 beyond the threshold and the current balance is broken.

  In this case, since it is necessary to reduce the current flowing to the first battery 11, the adjustment valve 40 is controlled to a position closing the second cooling path 32 so that the cooling air flows only to the first cooling path 31. Be sent. The cooling air sent into the first cooling path 31 strikes the first battery 11 to lower the battery temperature, thereby increasing the internal resistance value. Since the cooling air hardly hits the first electric wire 21 d connected to the downstream side of the first battery 11, the temperature of the first electric wire 21 d does not decrease and the resistance value does not decrease. On the other hand, since the second electric wiring 22d connected to the downstream side of the second battery 12 is hit, the temperature of the second electric wiring 22d is reduced and the resistance value is reduced.

  Due to this temperature control, the resistance value of the electric path increases on the first battery 11 side and the current decreases, and the resistance value of the electric path on the second battery 12 decreases and the current increases. Change in the direction. Therefore, the current flowing to the first battery 11 and the current flowing to the second battery 12 can be controlled in the direction in which the current balance is maintained.

  In the example of FIG. 3, the cooling air also hits the first electric wiring 21 u connected to the upstream side of the first battery 11. In this regard, for example, the length of the first electric wire 21u to be in contact with the cooling air may be made sufficiently shorter than the length of the first electric wire 21d to be in contact with the cooling air. It is possible to suppress the influence of the resistance value due to

[Operation / effect]
As described above, according to the battery cooling system 1 according to the embodiment of the present invention, the first electrical wiring 21 d electrically connected to the first battery 11 installed in the first cooling path 31 Are disposed in the second cooling path 32. In addition, at least a portion of the second electrical wiring 22 d electrically connected to the second battery 12 installed in the second cooling path 32 is disposed in the first cooling path 31. That is, the first electric wiring 21 d and the second electric wiring 22 d are cross-wired.

  For example, when the current flowing to the first battery 11 is larger than the current flowing to the second battery 12 and the current balance is broken by this cross wiring, the control valve 40 is controlled to perform the first cooling path. Only by feeding the cooling air only to 31, it is possible to simultaneously execute the decrease of the battery temperature in the first battery 11 and the temperature decrease of the second electric wiring 22 d in the second battery 12. That is, the internal resistance value of the first battery 11 can be increased, and at the same time, the resistance value of the second electrical wiring 22 d connected to the second battery 12 can be reduced. In addition, even when the current flowing to the second battery 12 is larger than the current flowing to the first battery 11 and the current balance is broken, the embodiment can be implemented similarly.

  As a result, the first battery 11 changes in the direction in which the current decreases, and the second battery 12 changes in the direction in which the current increases. Therefore, the current flowing to each battery is controlled in the direction to maintain balance. be able to. Therefore, according to the present battery cooling system, it is possible to easily carry out balance adjustment of the current supplied to each battery only by controlling the direction of sending the cooling air using one adjusting valve 40 and one fan 50. .

[Modification]
FIG. 4A is a perspective view of an essential part for explaining a schematic configuration example of another battery cooling system 2 according to an embodiment of the present invention. The battery cooling system 2 shown in FIG. 4A has a structure in which the first electric wiring 21 d and the second electric wiring 22 d are cross-wired, and the first cooling path 31 and the second cooling path 32 are crossed at the downstream side. It is realized by doing. Even with such a structure, since one battery and the other electric wiring can be cooled simultaneously, the useful effects of the present invention described above can be exhibited.

  FIG. 4B is a perspective view of an essential part for explaining a schematic configuration example of another battery cooling system 3 according to an embodiment of the present invention. The battery cooling system 3 shown in FIG. 4B not only simply cross-wires the first electrical wiring 21 d and the second electrical wiring 22 d, but also thermally applies the second battery 12 and the first battery 11 to each other. It is realized by contacting with. Even with such a structure, one battery and the other electric wiring can be simultaneously cooled, and one electric wiring is heated by the heat of the other battery, so that the above-mentioned useful effects of the present invention can be achieved. be able to.

  FIG. 4C is a perspective view of an essential part for explaining a schematic configuration example of another battery cooling system 4 according to an embodiment of the present invention. The battery cooling system 4 shown in FIG. 4C does not cross-wire the first electric wiring 21d and the second electric wiring 22d, but uses a heat pipe, which is one of the heat transport means, to carry out the first electric The first heat pipe 61 thermally connected to the wiring 21 d and the second heat pipe 62 thermally connected to the second electric wiring 22 d are cross-wired. Preferably, the first heat pipe 61 is disposed in the second cooling path 32 and is in thermal contact with the second battery 12, and the second heat pipe 62 is disposed in the first cooling path 31. And is in thermal contact with the first battery 11. In such a structure, one of the electric wires can be heated by the heat of the other battery through the heat pipe simultaneously with the cooling of the one battery, so that the above-described useful effects of the present invention can be exhibited. it can.

  In addition, in order to realize the battery cooling systems 1 to 4 according to the above-described embodiments, it is necessary to draw the electric wiring and the heat pipe through the wall surface of the duct 30. , You may use the general technique known.

  INDUSTRIAL APPLICABILITY The present invention is applicable to a battery cooling system that cools a battery by applying cooling air.

1, 2, 3, 4, 100 battery cooling system 11, 12, 110, 120 battery 21u, 21d, 22u, 22d, 210d electrical wiring 30, 300 duct 31, 32 cooling path 40 adjusting valve 50 fan 61, 62 heat pipe

Claims (1)

A system that cools the battery by blowing cooling air,
A first battery installed in the first cooling path;
A second battery installed in a second cooling path different from the first cooling path;
A control valve configured to control a cooling air to be circulated in the first cooling path and a cooling air to be circulated in the second cooling path based on the states of the first battery and the second battery;
At least a portion of a first electrical wire electrically connected to the first battery or at least a portion of a heat pipe thermally connected to the first electrical wire, in the second cooling path Placed in
At least a portion of a second electrical wire electrically connected to the second battery or at least a portion of a heat pipe thermally connected to the second electrical wire, in the first cooling path Placed in
Battery cooling system.