JP5733130B2 - Battery cooling system - Google Patents

Description

  The present invention relates to a battery cooling device provided in a battery case that houses a battery.

  In general, the discharge characteristics of a battery vary depending on the temperature at which it is used. For example, it is known that when a battery is used in a high temperature state, the remaining capacity tends to decrease because self-discharge increases. In addition, use in a high temperature state tends to cause deterioration of the battery, leading to a reduction in battery life. However, since the battery generates heat by charging and discharging, a temperature rise is inevitable. Therefore, when using a battery, it is required to cool appropriately.

  As a method for cooling the battery, for example, it is conceivable to air-cool the battery. However, when the battery is air-cooled, it is necessary to flow air around the battery. For example, when the battery is housed in a case and mounted on a vehicle, an air flow is generated in the battery case. And the battery must be cooled. As a method of flowing air into the battery case, a technique is known in which the inside of the battery case that accommodates the battery and the vehicle interior are communicated and the cooled air in the vehicle interior is sent into the battery case.

  However, in this method of communicating the vehicle interior and the battery case, the temperature of the air for cooling the battery depends on the temperature of the air in the vehicle interior. In other words, when the air in the vehicle compartment is warm (when it is not cold), the battery cannot be sufficiently cooled even if the air is blown into the battery case.

  On the other hand, as a technique for cooling only the battery independently (that is, without being influenced by the temperature of the air in the passenger compartment), an evaporator and a blower fan are built in the battery case as in Patent Document 1, for example. There is what I did. This cools the battery by cooling the air by heat exchange between the refrigerant flowing inside the evaporator and the air around the evaporator, and flowing the cooled air toward the battery by a blower fan.

  Thus, if air is cooled using an evaporator, only a battery can be cooled independently. However, when using an evaporator, condensed water (also referred to as condensed water or condensed water) is generated in the evaporator due to heat exchange between the refrigerant and air and drops on the bottom of the battery case. It is necessary to discharge outside. In Patent Document 1, a drainage drain is provided in the battery case, and condensed water is discharged from the drainage drain to the outside of the battery case.

  However, in the configuration of the battery case of Patent Document 1, when the battery case is mounted under the floor of the vehicle (in other words, when the battery case is mounted outside the passenger compartment), the battery case is submerged or exposed to water. At this time, water may flow backward from the drainage drain into the battery case. In other words, assuming the case where the battery case is mounted outside the passenger compartment, the battery case is made more watertight (that is, the ability to prevent water from entering from outside) in case the battery case is submerged. It is preferable to keep it.

  In addition, although it is not a technique regarding an evaporator, the technique like patent document 2 is known as a technique which discharges the accumulated water to the exterior, for example. In this case, in order to completely remove water (drain water) accumulated in the drain pan arranged in the casing of the indoor unit, an electric heater is provided in the drain pan, and the drain water is heated and evaporated.

JP 2008-54379 A JP 2004-340523 A

  It is conceivable to apply the technique disclosed in Patent Document 2 to the removal of water generated in the evaporator. In this case, the condensed water of the evaporator can be expected to be discharged from the battery case to the outside through a minute hole called a breathing plug through which only the gas provided in the battery case passes.

However, when the condensed water is heated to a water vapor by a heater, the water vapor that has not been discharged from the evaporator to the outside of the battery case is cooled in the battery case, returned to the water, and accumulated in the battery case. In other words, the condensed water which has become water vapor in the evaporator is sent into the battery case through the duct together with air. And it flows in the battery case by the blower fan. At this time, the water vapor that has not been discharged from the breathing plug to the outside of the battery case returns to the water at a low temperature in the battery case.
Therefore, even if the water tightness of the battery case is ensured, there is a possibility that the condensed water in the evaporator is accumulated in the battery case. In addition, a device for discharging the water accumulated in the battery case is also required.

This case has been devised in view of such a problem, and the condensed water of the evaporator generated when cooling the battery can be removed from the battery case while ensuring the water tightness of the battery case. An object is to provide a battery cooling device.
The present invention is not limited to this purpose, and is a function and effect derived from each configuration shown in the embodiments for carrying out the invention described later, and other effects of the present invention are to obtain a function and effect that cannot be obtained by conventional techniques. Can be positioned.

(1) A battery cooling device disclosed herein is a battery cooling device that is provided in a battery case that houses a battery and cools the battery, and is disposed in the battery case, and the air in the battery case An evaporator that cools the battery and an exhaust part that is provided above the side surface of the battery case and through which air flows, and an anode electrode and a cathode electrode that are connected to a power supply circuit are disposed on a bottom surface below the evaporator. It is characterized by.

(2) It is preferable that a tray portion is provided at the bottom of the evaporator, and the anode electrode and the cathode electrode are disposed below the evaporator and in contact with the bottom surface of the tray portion.
(3) It is preferable that the said anode electrode and the said cathode electrode are arrange | positioned in the deepest part of the said bottom face of the said tray part.

(4) An electric fan is provided in the battery case and generates the air flow in the battery case, and the anode electrode and the cathode electrode are energized in conjunction with the operation of the electric fan. Is preferred.
(5) It is preferable that the said battery case is mounted under the floor of a vehicle.

According to the battery cooling device of the disclosure, condensation is accumulated on the bottom surface below the evaporator by causing electricity to flow (that is, energizing) through the electric circuit to the anode electrode and the cathode electrode disposed on the bottom surface below the evaporator. Water can be electrolyzed and discharged to the outside of the battery case from an exhaust part provided above the side surface of the battery case. As a result, it is possible to prevent the condensed water from accumulating in the evaporator, and it is not necessary to provide a device (such as a drainage drain) for discharging the condensed water to the outside of the battery case. Sex can be secured.

It is a schematic diagram which shows the battery cooling device which concerns on one Embodiment, (a) is AA arrow sectional drawing of Fig.2 (a), and is a figure which shows the internal structure of an evaporator unit, (b) is an evaporator unit. FIG. It is a typical whole block diagram of the battery cooling device which concerns on one Embodiment, (a) is a top view, (b) is a side view. It is a typical disassembled perspective view which shows the mounting structure of the battery unit which has the battery cooling device which concerns on one Embodiment.

Hereinafter, embodiments will be described with reference to the drawings. Note that the embodiment described below is merely an example, and there is no intention to exclude various modifications and technical applications that are not explicitly described in the following embodiment.
The configuration of the battery cooling device according to the present embodiment will be described with reference to FIGS. This battery cooling device is suitable for use in a battery mounted on an electric vehicle, a hybrid vehicle, or the like that requires a large driving force. Here, a description will be given of an example in which the battery cooling device is applied as a driving source for an electric vehicle. Hereinafter, as a reference for the direction in explaining the mounting state and arrangement of the battery with respect to the electric vehicle, the direction of gravity is assumed to be downward, and the opposite is assumed to be upward.

[1. Constitution]
[1-1. overall structure]
As shown in FIG. 3, the electric vehicle (vehicle) 1 includes a traveling motor and a charging device (both not shown) disposed behind the vehicle body 2, a battery unit 10 disposed below the floor of the vehicle body 2, and the like. And. Further, a floor panel 3 is provided above the battery unit 10, and a front seat 4F and a rear seat 4R are disposed above the floor panel 3, that is, in the passenger compartment.

  The floor panel 3 is formed of, for example, a sheet metal, and extends in the front-rear direction and the left-right direction of the vehicle body 2 to form a floor portion of the vehicle body 2. The floor panel 3 is fixed to a predetermined position of a frame structure including a side member (not shown) constituting the vehicle body 2 by welding or the like. The battery unit 10 is arranged separately from the floor panel 3 below the floor panel 3, that is, below the floor that is outside the vehicle body. An under cover 5 is disposed below the battery unit 10 and is fixed to a frame structure or the like.

  As shown in FIGS. 2A and 2B, the battery unit 10 includes a plurality of battery modules (hereinafter simply referred to as batteries) 12, a cooling device 14, an electronic component (not shown), and the like inside a battery case 11. And is configured. The battery case 11 includes a tray 11a and a lid 11b (see FIG. 1A). The battery case 11 is provided with a plurality of breathing plugs 13 (three in FIG. 2B) above the opposing side surfaces.

  The breathing plug 13 is provided with a membrane that allows gas to pass but not liquid, and the air pressure in the battery case 11 is adjusted by air flowing through the breathing plug 13. The The battery 12 is configured by incorporating a plurality of battery cells (cell batteries) in a container. Here, twelve batteries 12 are arranged in the battery case 11 with a gap therebetween. Yes. In addition, the battery 12 here is a driving battery that stores electric power or electric energy serving as a driving source of the vehicle 1.

  The cooling device 14 is provided at one end in the longitudinal direction of the battery case 11, and includes an evaporator unit 20 that includes an evaporator 22 that cools the air in the battery case 11, and an electric motor that flows the air cooled by the evaporator 22 into the battery case 11. The fan 19 includes a duct 18 that communicates the evaporator unit 20 and the electric fan 19. In addition, the number of the batteries 12 arrange | positioned in the battery case 11 and the position of the cooling device 14 in the battery case 11 are not restricted to what is shown in FIG.

[1-2. Configuration of cooling device]
As shown in FIG. 1 (a), an evaporator unit 20 disposed in a battery case 11 includes an evaporator 22 having a plurality of fins in an evaporator case 21 (hereinafter simply referred to as a case 21), and condensed water. It has a tray section 23 that accumulates, an introduction flow path 24 that sends a liquid or gas-liquid mixed refrigerant to the evaporator 22, and a discharge flow path 25 that sends the refrigerant from the evaporator 22.

  The evaporator 22 has a plurality of heat transfer tube elements arranged in parallel with each other at an appropriate interval in the longitudinal direction of the case 21 and a plurality of corrugated fins sandwiched between adjacent heat transfer tube elements. It is the composition. An inlet passage 24 and a discharge passage 25 are connected to the evaporator 22. A flow path through which the refrigerant flows is formed in the heat transfer tube element of the evaporator 22, and the refrigerant sent from the introduction flow path 24 flows through the flow path in the heat transfer tube element and is sent out from the discharge flow path 25. .

  This refrigerant evaporates by taking away ambient heat while flowing through the flow path in the heat transfer tube element. Thereby, the temperature of the evaporator 22 falls and the air which flows between the fins which comprise the evaporator 22 is cooled. That is, in the evaporator 22, heat exchange is performed between the refrigerant and the air. The case 21 is provided with a plurality of holes 21 g for introducing the air in the battery case 11 into the evaporator 22 at positions facing the fins of the evaporator 22.

  The tray part 23 is a part that is provided at the bottom of the case 21 of the evaporator unit 20 and stores condensed water generated during heat exchange in the evaporator 22. In the tray portion 23, condensed water is collected on the bottom surface 21 a below the case 21 by forming an inclined portion 21 b on a part of the bottom surface 21 a of the case 21. That is, as shown in FIG. 1B, the tray portion 23 is formed to be inclined obliquely upward with respect to the horizontal bottom surface 21a and the bottom surface 21a of the case 21 (in other words, with respect to the horizontal direction). It is formed by being surrounded by an inclined portion 21b, a side surface 21c of the case 21 that faces the inclined portion 21b, and a pair of side surfaces 21d and 21e that are perpendicular to the bottom surface 21a, the inclined portion 21b, and the side surface 21c. Part.

  On the bottom surface 23B of the tray portion 23 (that is, the bottom surface 21a of the case 21), an anode electrode 26 and a cathode electrode 27 connected to the power supply circuit 28 are disposed with a space therebetween. The power supply circuit 28 is connected to a power supply (not shown) and is energized in conjunction with the operation of the electric fan 19.

  The anode electrode 26 includes a first portion 26a that is in contact with the bottom surface 23B of the tray portion 23, and a second portion 26b that is continuously formed by bending upward from one end of the first portion 26a. In other words, the anode electrode 26 is substantially L-shaped (that is, bent upward at a substantially right angle) in which the first portion 26a is provided along the bottom surface 23B and the second portion 26b is provided substantially perpendicular to the bottom surface 23B. Shape).

  The cathode electrode 27 is formed similarly to the shape of the anode electrode 26. That is, the cathode electrode 27 includes a first portion 27a that is in contact with the bottom surface 23B of the tray portion 23, and a second portion 27b that is continuously formed by bending upward from one end of the first portion 27a. In other words, the cathode electrode 27 is substantially L-shaped (that is, bent upward at a substantially right angle) in which the first portion 27a is provided along the bottom surface 23B and the second portion 27b is provided substantially perpendicular to the bottom surface 23B. Shape). Each of the anode electrode 26 and the cathode electrode 27 constitutes a pair of electrodes.

  Here, the pair of the anode electrode 26 and the cathode electrode 27 is disposed at the approximate center in the longitudinal direction of the bottom surface 23B and the approximate center in the lateral direction (that is, approximately the center of the bottom surface 23B). The first portions 26a and 27a of the anode electrode 26 and the cathode electrode 27 extend in the longitudinal direction of the bottom surface 23B, and the entire first portions 26a and 27a are in contact with the bottom surface 23B. Further, the second portions 26b and 27b of the anode electrode 26 and the cathode electrode 27 are provided to have substantially the same length as the height (depth) of the tray portion 23, and the power circuit 28 is connected to the tip thereof. . In addition, since the evaporator 22, the introduction flow path 24, and the discharge flow path 25 are disposed above the tray portion 23, the lengths of the second portions 26b and 27b of the anode electrode 26 and the cathode electrode 27 are not limited thereto. It should just be set to such an extent that it does not touch.

  The introduction channel 24 is a pipe that is connected to the lower side of the evaporator 22 and feeds the refrigerant into the evaporator 22. The discharge passage 25 is a pipe that is connected to the upper side of the evaporator 22 and sends out the refrigerant from the evaporator 22. The connection positions of the introduction flow path 24 and the discharge flow path 25 are not limited to this.

  A duct 18 for sending the air cooled by the evaporator 22 into the battery case 11 is connected to the upper surface 21 f of the case 21 of the evaporator unit 20. An electric fan 19 is connected to the downstream side of the duct 18. The electric fan 19 causes the cool air that has circulated through the duct 18 to flow toward the battery 12. That is, the electric fan 19 generates an air flow in the battery case 11. Here, the electric fan 19 is connected to the same power source as the power source to which the power circuit 28 is connected.

[2. Action, effect]
Since the battery cooling device 14 according to the present embodiment is configured as described above, the battery 12 is cooled as follows.
The battery 12 housed in the battery case 11 and disposed with a gap therebetween is cooled by the air flowing through the gap. This air flows through the gaps between the batteries 12 and absorbs the heat of the batteries 12, thereby cooling the batteries 12 and increasing the temperature. The air whose temperature has risen is introduced into the evaporator 22 along the air flow generated by the electric fan 19 (the white arrow in FIG. 1A). The air introduced into the evaporator 22 is circulated between the fins of the evaporator 22 and cooled, and then flows through the duct 18 to the electric fan 19 (black arrow in FIG. 1A). Then, the air cooled by the electric fan 19 is caused to flow toward the battery 12, thereby cooling the battery 12.

  Further, in the evaporator 22, condensed water is generated by heat exchange between the refrigerant and the air, and this condensed water gradually falls downward and travels down the inclined portion 21b to the bottom surface 23B of the tray portion 23 (that is, the case 21). It collects on the inner bottom surface 21a). The accumulated condensed water is electrolyzed by flowing electricity through a pair of electrodes provided on the bottom surface 23B. In other words, when the pair of anode electrode 26 and cathode electrode 27 are energized, the condensed water is decomposed into oxygen gas and hydrogen gas at the first portions 26a and 27a of the anode electrode 26 and the cathode electrode 27 in contact with the condensed water.

  Oxygen gas and hydrogen gas generated by electrolysis are discharged from the breathing plug 13 provided in the battery case 11 to the outside of the battery case 11. In addition, since the electrolysis by the anode electrode 26 and the cathode electrode 27 is gradually performed over a long period of time, the oxygen gas and hydrogen gas that are generated in a short time are extremely small, and the respiratory plug is gradually 13 is discharged.

  Therefore, according to the battery cooling device 14, electricity is supplied (that is, energized) through the electric circuit 28 to the anode electrode 26 and the cathode electrode 27 disposed on the bottom surface 21 a inside the evaporator unit 20 (below the evaporator 22). ), The condensed water collected on the bottom surface 21a in the evaporator unit 20 can be electrolyzed into oxygen gas and hydrogen gas, and discharged to the outside of the battery case 11. As a result, it is possible to prevent the condensed water from accumulating in the evaporator unit 20, and it is not necessary to provide a device (for example, a drainage drain) for discharging the condensed water to the outside of the battery case 11. The water tightness of the case 11 can be ensured.

  Further, since condensed water is gasified by electrolysis, the water does not return to water again in the battery case 11 as compared with the case where the water is discharged out of the battery case 11 as water vapor. It can be prevented from accumulating. In addition, it takes a considerable amount of time for condensed water to gasify by electrolysis (that is, to be decomposed into oxygen gas and hydrogen gas), and in a short time the generated oxygen gas and hydrogen gas are extremely small. Therefore, safety is not impaired.

  Further, since the evaporator unit 20 is provided with the tray portion 23 having the inclined portion 21b, condensed water can be accumulated on the bottom surface 23B of the tray portion 23 (that is, the bottom surface 21a of the case 21). By disposing the anode electrode 26 and the cathode electrode 27 on the bottom surface 23B of 23, the condensed water can be efficiently electrolyzed. Moreover, since the electrode can be disposed without interfering with the evaporator 22 by forming the inclined portion 21b, the degree of freedom in installing the electrode can be increased. Further, since the anode electrode 26 and the cathode electrode 27 are formed in a substantially L shape, and the second portions 26b and 27b are provided substantially perpendicular to the bottom surface 23B, they are formed at the tips of the second portions 26b and 27b. The connected power supply circuit 28 is safe without coming into contact with condensed water.

  Further, since the air flow is generated in the battery case 11 by the electric fan 19, the battery 12 in the battery case 11 can be actively cooled. At this time, in conjunction with the operation of the electric fan 19, that is, when air is being cooled by the evaporator 22, the anode electrode 26 and the cathode electrode 27 are energized to electrolyze the condensed water. Water can be reliably prevented from accumulating in the evaporator unit 20.

Further, the battery cooling device 14 is applied to the battery unit 10 (that is, the battery case 11) mounted under the floor of the vehicle 1, and the battery case 11 may be submerged or exposed to water. Therefore, higher water tightness is required. On the other hand, in the case of the battery cooling device 14 that gasifies and discharges condensed water generated in the evaporator 22 by electrolysis, there is no need to provide drainage drain or the like, so there is a path through which water enters from the outside. Therefore, high water tightness can be ensured and it is more effective.
In the case where the battery 12 constituting the battery unit 10 is a driving battery that serves as a driving source for the vehicle 1, the driving battery is often mounted under the floor of the vehicle 1 because of its large capacity. 14 is particularly effective when applied to a drive battery.

[3. Modified example]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above embodiment, the tray portion 23 is provided at the bottom of the case 21 of the evaporator unit 20, but the shape of the tray portion 23 is not limited to that described above. For example, the tray portion may have a shape in which two surfaces inclined with respect to the bottom surface 21a are provided (that is, a shape in which the central portion in the short direction of the bottom surface 23B is deepest).

In this case, it is preferable that the anode electrode 26 and the cathode electrode 27 are provided in the deepest part of the bottom face of the tray part. Condensed water generated from the evaporator 22 accumulates in the deepest part (deepest part) of the tray part along the inclined surface. With such a configuration, the condensed water can be electrolyzed even when the amount of condensed water is small. The amount of water stored can be reduced.
Further, the tray portion 23 may not be formed integrally with the case 21. That is, a configuration in which the tray portion is provided separately from the case 21 and is coupled to the bottom portion of the case 21 may be employed.

  Moreover, the structure which does not have the inclination part 21b in the bottom face of the evaporator unit 20 below may be sufficient. That is, the bottom surface 21a of the case 21 may be formed in a horizontal plane so that condensed water is not collected. In this case, since condensed water is expected to spread over the entire bottom surface 21a, if a plurality of electrodes (that is, the anode electrode 26 and the cathode electrode 27) are provided on the bottom surface 21a, any portion of the bottom surface 21a is electrolyzed. be able to.

  Further, the shape and arrangement of the anode electrode 26 and the cathode electrode 27 are not limited to those described in the above embodiment. For example, the lengths of the second portions 26b and 27b may be different from the height of the tray portion 23, and the interval between the anode electrode 26 and the cathode electrode 27 only needs to be long enough not to contact each other. It is not limited to that shown in FIG. Moreover, in the said embodiment, although the 1st parts 26a and 27a of the anode electrode 26 and the cathode electrode 27 are all extended in the longitudinal direction of the bottom face 23B, you may extend in the transversal direction. Furthermore, the number of anode electrodes 26 and cathode electrodes 27 is not limited to a pair, and a plurality of pairs may be provided.

Further, the duct 18 may be connected to the side surface of the case 21 instead of the upper surface 21 f of the case 21.
Moreover, it is good also as a structure which flows an electric current only to an electrode. That is, the energization to the anode electrode 26 and the cathode electrode 27 may not be performed in conjunction with the operation of the electric fan 19. For example, the energization may be always performed or the energization timing may be determined by an in-vehicle electronic control device (not shown). It is good also as a structure which is controlled.

  Further, the battery cooling device 14 is not limited to the one applied to the driving battery unit 10 mounted under the floor of the vehicle 1, and may be applied to a battery unit mounted in the vehicle interior. . Further, the battery cooling device 14 is not limited to those applied to a battery unit mounted on a vehicle such as an electric vehicle or a hybrid vehicle, and can be applied as long as it has a configuration in which a battery is accommodated in a battery case. .

1 Vehicle 10 Battery Unit 11 Battery Case 12 Battery Module (Battery)
13 Breathing plug 14 Cooling device 18 Duct 19 Electric fan 20 Evaporator unit 21 Evaporator case 22 Evaporator 23 Tray part 23B Bottom face (deepest part)
24 Introducing flow path 25 Discharging flow path 26 Anode electrode 27 Cathode electrode 28 Power supply circuit

Claims (5)

A battery cooling device that is provided in a battery case that houses a battery and cools the battery,
An evaporator disposed in the battery case for cooling air in the battery case ;
Provided above the side surface of the battery case, and an exhaust part through which air flows ,
A battery cooling device, wherein an anode electrode and a cathode electrode connected to a power supply circuit are disposed on a bottom surface below the evaporator. Having a tray at the bottom of the evaporator,
The battery cooling device according to claim 1, wherein the anode electrode and the cathode electrode are disposed below the evaporator and in contact with a bottom surface of the tray portion. The battery cooling device according to claim 2, wherein the anode electrode and the cathode electrode are disposed at a deepest portion of the bottom surface of the tray portion. An electric fan disposed in the battery case and generating the air flow in the battery case;
The battery cooling device according to claim 1, wherein the anode electrode and the cathode electrode are energized in conjunction with the operation of the electric fan. The battery cooling device according to claim 1, wherein the battery case is mounted under a floor of a vehicle.

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