CN107112608B - Thermal management device of battery pack - Google Patents

Abstract

This application discloses a thermal management device for a battery pack, comprising a battery box with an outwardly protruding inner wall, two first heat sinks equipped with bidirectional fans, a second heat sink equipped with several cooling fans, two additional heat sinks with several ventilation holes, a heater, and a battery management circuit. This thermal management device creatively solves the contradiction between the need for a good heat dissipation structure and a heating and insulation structure in the battery box in the prior art, ensuring that the battery pack in the battery system can charge and discharge in a suitable environment, controlling the temperature rise and temperature difference inside the battery box, improving the cycle life of the battery pack, and reducing various safety risks caused by high and low temperatures.

Description

A thermal management device for a battery pack

technical field

The present application relates to the technical field of thermal management of battery packs, in particular to a thermal management device of a battery pack.

Background technique

Many battery systems, such as power lithium-ion battery systems, have a large number of cells and generate a lot of heat during operation (especially in the process of high-rate charge and discharge). In the battery system box module, the internal cells It is very difficult to dissipate the heat of the body cells. The accumulation of heat will cause a high temperature rise inside the battery box, and the temperature difference inside the battery box is also large, which not only reduces the cycle life of the battery pack, but also causes serious damage. safe question. Therefore, it is required that the battery case has a good heat dissipation structure.

On the other hand, when the battery pack is charged and discharged at low temperature, especially below zero temperature, not only the charging and discharging efficiency is low, but also serious irreversible attenuation of the battery capacity, and reducing the overall performance of the battery, especially safety issues . Therefore, it is required that the battery box has a good heating and thermal insulation structure.

To sum up, on the one hand, the battery box is required to have a good heat dissipation structure, and on the other hand, the battery box is required to have a good heating and thermal insulation structure. These contradictory requirements make it difficult to design a battery box that meets the requirements in the prior art. body and battery system.

SUMMARY OF THE INVENTION

The thermal management device of the battery pack of the present application includes:

a battery box, the inner wall circumference of the battery box bulges outwards;

Two first radiating plates, which are respectively fixed on a pair of opposite inner walls in the battery box, and form air ducts with the outer protrusions on the inner walls; wherein, each first radiating plate is provided with a two-way fan ;

Two second radiating plates, which are respectively fixed on another pair of opposite inner walls in the battery box, and form air ducts with the outer protrusions on the inner wall; wherein, each second radiating plate is provided with several cooling fan;

Two pieces of heat-dissipating plates, the two pieces of heat-dissipating plates are arranged in parallel at a certain distance to form air ducts, which are both parallel to the second heat-dissipating plate and fixed to the battery box or the first heat-dissipating plate, wherein the The two ends of the added radiator plate are respectively arranged at the two-way fans of the two first radiator plates, so that the air duct formed by the two pieces of heat-dissipating plates can receive the air supply or exhaust of the two-way fan; There are several ventilation holes on the heat dissipation plate;

a heater, which is arranged on the opposite side of the heat-dissipating plate;

A battery management circuit, which is electrically connected to the bidirectional fan, the cooling fan and the heater, respectively, is used to control the operation of the bidirectional fan, the cooling fan and the heater.

In a preferred embodiment, fins are provided on the side of the first radiating plate and/or the second radiating plate facing the inner wall of the battery box; and/or, the opposite side of the heat-dissipating plate is provided with fins .

In a preferred embodiment, the distance from the top plane of the fins on the first heat dissipation plate to the bidirectional fan is at least 5 mm, and the distance from the top plane of the fins on the second heat dissipation plate to the heat dissipation fan is at least 8 mm. mm.

In a preferred embodiment, the bidirectional fan is arranged in the middle of the first heat dissipation plate.

In a preferred embodiment, the two ends of the heat-dissipating plate are respectively arranged at the center of the two-way fan of the two first heat-dissipating plates, so that the air duct formed between the heat-dissipating plates receives the largest amount of the two-way fan. Supply and exhaust air volume.

In a preferred embodiment, each second heat dissipation plate is symmetrically provided with two heat dissipation fans.

In a preferred embodiment, the thermal management device of the battery pack further includes an insulating windshield member disposed on the periphery of the heat dissipation fan on the second heat dissipation plate. The thermal management device of the battery pack further includes a heat insulating film, and the heat insulating film is fixed on the side of the first heat dissipation plate and the second heat dissipation plate not facing the inner wall of the battery box through single-sided adhesive and screws.

In a preferred embodiment, the heater is a PTC heater.

In a preferred embodiment, the heater is fixed on the heat-dissipating plate by pouring thermally conductive silica gel.

According to the thermal management device of the battery pack implemented above, when heat dissipation is required, the battery management circuit turns on the cooling fan, radiates the heat to the heat-dissipating plate, and discharges the heat to the air duct formed between the heat-dissipating plates through the ventilation holes of the heat-dissipating plate. At the same time, the two-way fan is turned on to reverse the ventilation, and the hot air in the air duct between the radiating plates is discharged to the air duct formed by the first radiating plate, the second radiating plate and the inner wall of the battery box and circulates in it, thereby To achieve the effect of heat dissipation and reduce the temperature difference in the battery box; when heating is required, the battery management circuit turns on the two-way fan to rotate forward to continuously supply air to the air duct between the heat sinks, and turns on the heater to start heating, and the heated wind continues It is discharged to the second heat dissipation plate through the ventilation holes on the heat dissipation plate. During this process, the hot air heats the battery pack, and the wind is continuously drawn into the air duct between the heat dissipation plate and the heat dissipation plate. After heating, it continuously dissipates heat to the second heat dissipation plate. The plate is removed, which not only improves the heating efficiency, but also effectively reduces the temperature difference in the battery box, avoiding that the temperature difference in the battery box is still large when the heating preset temperature is partially reached in the battery box and the heater stops heating. The thermal management device of the battery pack of the present application creatively solves the contradictory requirements of the prior art that the battery box needs a good heat dissipation structure and a heating and heat preservation structure, and ensures that the battery pack in the battery system can be charged and discharged in a suitable environment. , control the temperature rise and temperature difference in the battery box, improve the cycle life of the battery pack, and reduce various safety risks caused by high and low temperature.

Description of drawings

FIG. 1 is a schematic structural diagram of a thermal management device for a battery pack according to an embodiment of the present application without a battery box;

2 is a schematic structural diagram of a thermal management device for a battery pack according to an embodiment of the present application;

3 is a schematic structural diagram of a second heat dissipation plate and its upper components in a thermal management device for a battery pack according to an embodiment of the present application;

4 is a schematic structural diagram of a first heat dissipation plate and its upper components in a thermal management device for a battery pack according to an embodiment of the present application;

5 is a schematic structural diagram of a heat dissipation plate and its upper components in a thermal management device for a battery pack according to an embodiment of the present application;

6 is a simplified schematic diagram of a thermal management device for a battery pack according to an embodiment of the present application when heat is dissipated;

FIG. 7 is a schematic diagram of the thermal management device for a battery pack according to an embodiment of the application when the battery pack is placed in the heat dissipation process, wherein FIG. 7(b) and FIG. 7(c) are the F-F plane and the D-D plane of FIG. 7(a) respectively. sectional view of ;

8 is a schematic diagram of the thermal management device for a battery pack according to an embodiment of the present application when the battery pack is placed and heated, wherein FIG. 8( b ) is a cross-sectional view of the F-F plane of FIG. 8( a ).

Detailed ways

The present application will be further described in detail below through specific embodiments in conjunction with the accompanying drawings.

Existing technologies still cannot solve the contradictory demands of heat dissipation and heating and heat preservation of battery systems and battery boxes. For example, external air conditioner heat dissipation structures or liquid cooling heat dissipation structures are generally used for heat dissipation, and each row of battery packs is heated in series. The structure of the film is fixed with adhesive on one side for heating. First of all, it is difficult to ensure the waterproof level of the battery system with the heat dissipation structure of the external air conditioner, and the power consumption during operation is also large; the liquid cooling structure requires a separate liquid-filled radiator for the battery system to complete the heat dissipation, which is complicated in structure and complex in production process. High cost and difficult modular assembly, and there are also dangers such as cooling liquid leakage; secondly, each row of battery packs is inserted in series with a heating film fixed with a single-sided adhesive, which requires a large number of heating films, high power consumption and single-sided heating. The adhesive-backed assembly method is easy to displace and loosen the heating film, resulting in damage to the heating film; finally, when the above-mentioned heat dissipation structure and heating structure exist in one system, due to the requirement of waterproof level, the battery system box needs to be strictly sealed Therefore, the entire device and structure are more inclined to heating and heat preservation, and do not have a good heat dissipation function.

In order to solve the contradictory requirements of the battery system and the battery box for heat dissipation and heating and heat preservation, the present application discloses a thermal management device for a battery pack (hereinafter referred to as the thermal management device), which will be described in detail below.

Referring to FIGS. 1 to 5 , the thermal management device of the present application includes a battery box 101 , two first heat dissipation plates 103 , two second heat dissipation plates 105 , two additional heat dissipation plates 107 , a heater 109 and a battery management circuit (not shown in the picture).

The battery box 101 is used for placing the battery pack, and the inner circumference of the battery box 101 protrudes outward.

Two pieces of first heat dissipation plates 103 are respectively fixed on a pair of opposite inner walls of the battery box 101 , and form air ducts with the outer protrusions on the inner walls; each of the first heat dissipation plates 103 is provided with a bidirectional fan 111 . The bidirectional fan 111 refers to a fan that can draw air (air suction) or exhaust air. In a specific embodiment, the bidirectional fan 111 may be a bidirectional fan fan. In a preferred embodiment, the bidirectional fan 111 is disposed in the middle of the first heat dissipation plate 103 . In order to increase the heat exchange surface area, in a preferred embodiment, fins 113 , for example, aluminum fins, are provided on the side of the first heat dissipation plate 103 facing the inner wall of the battery box 101 . In order to make the air extraction and exhaust effect of the bidirectional fan 111 better, in a preferred embodiment, the distance from the top plane of the fins on the first heat dissipation plate 103 to the bidirectional fan 111 is at least 5 mm.

Two pieces of second heat dissipation plates 105 are respectively fixed on the other pair of opposite inner walls in the battery box 101, and form air ducts with the outer protrusions on the inner walls; wherein each second heat dissipation plate 105 is provided with a number of cooling fans 115. In a preferred embodiment, each second cooling plate 105 is provided with two cooling fans 115 symmetrically. In order to improve the effect of the cooling fan 115 , in an embodiment, the thermal management device of the present application further includes an insulating wind shield 119 disposed on the second cooling plate 105 around the cooling fan 115 . In order to increase the heat exchange surface area, in a preferred embodiment, the side of the second heat dissipation plate 105 facing the inner wall of the battery box 101 is also provided with fins 113, for example, aluminum fins are provided. In order to make the effect of the cooling fan 115 better, in a preferred embodiment, the distance from the top plane of the fins on the second cooling plate 105 to the cooling fan 115 is at least 8 mm.

Two pieces of heat-dissipating plates 107 are arranged in parallel at a certain distance to form air ducts. Both pieces of heat-dissipating plates 107 are parallel to the second heat-dissipating plate 105 and fixed to the battery box 101 or the first heat-dissipating plate 103 . The two ends are respectively disposed at the two-way fans 111 of the two first radiating plates 103, so that the air ducts formed by the two pieces and the radiating plates 107 can receive air supply or exhaust air from the two-way fans 111; Several ventilation holes 117 are provided. In a specific embodiment, the plane where the heat dissipation plate 107 is added is perpendicular to the bottom plane of the battery box 101 and the plane where the first heat dissipation plate 103 is located, respectively. In order to increase the heat exchange surface area, in a preferred embodiment, fins 113, such as aluminum fins, are also provided on the opposite side of the heat dissipation plate 107. In order to allow the air duct formed between the added heat dissipation plate 107 to receive the maximum air supply and exhaust volume of the bidirectional fan 111 , in one embodiment, the two ends of the added heat dissipation plate 107 are respectively disposed on two bidirectional fans of the first heat dissipation plate 103 . the center of the place.

The heaters 109 are arranged on the opposite sides of the heat-dissipating plates 107 . In one embodiment, the heater 109 may be a PTC heater. The heater 109 can be fixed on the heat-dissipating plate 107 by pouring thermal conductive silica gel.

The battery management circuit is electrically connected to the bidirectional fan 111 , the cooling fan 115 and the heater 109 respectively, and is used to control the operation of the bidirectional fan, the cooling fan and the heater.

In order to achieve better heat dissipation and heating effects, in a preferred embodiment, the thermal management device may further include a thermal insulation film 119. Considering that this is a thermal management device for a battery pack, the thermal insulation film 119 may be an insulating flame retardant barrier. hot film. The heat insulating film 119 is fixed on the side of the first heat dissipation plate 103 and the second heat dissipation plate 105 not facing the inner wall of the battery box 101 by single-sided adhesive and screws.

It should be noted that the connection method of "fixed setting" involved in this application refers to "fixed setting", and the implementation methods include but are not limited to fixing by screws, assisted fixing by brackets, and the like. In addition, when the first heat dissipation plate 103 and the second heat dissipation plate 105 are fixed on the inner wall of the battery box 101, they can be fixed in the concave position of the inner wall of the battery box 101, so that the first heat dissipation plate 103 and the second heat dissipation plate 105 can be connected to the inner wall of the battery box 101. The outer bulge of the inner wall forms a relatively closed air channel.

The working principle of the thermal management device of the present application will be described below.

Please refer to FIG. 6 and FIG. 7 , the arrows in the figures are schematic diagrams of wind directions, and the heat dissipation principle is as follows. The battery box 101 is provided with a battery module with a through-type ventilation duct, for example, a lithium-ion battery module with a through-type ventilation duct is placed. When the temperature of the battery pack reaches a preset value, such as 55°C, when the battery The management circuit controls to turn on the cooling fan 115, and the cooling fan 115 supplies air into the battery box 101. The air is discharged to the cooling plate 107 through the through-type ventilation duct of the battery pack, and enters the cooling plate 107 through the ventilation holes 117 on the cooling plate 107. Add the air ducts between the cooling plates 107. During this process, the wind will take away the heat of the battery pack and become hot air; at the same time, the battery management circuit controls to turn on the two-way fan 111 to reverse the exhaust air, so that the air enters the cooling plate 107 The hot air in the air duct between them is extracted and discharged to the first heat dissipation plate 103, the second heat dissipation plate 105 and the outer protrusions on the wall of the battery box 101 to form an air channel, and circulates in it, so as to achieve heat dissipation and reduce the internal pressure of the battery box. The effect of temperature rise and temperature difference provides a working environment with a suitable temperature for the battery module and improves the cycle life of the battery pack.

Please refer to FIG. 8 , the arrow in the figure is a schematic diagram of the wind direction, and the heating principle is as follows. When the working temperature of the battery pack is a low temperature environment and needs to be heated, the battery management circuit turns on the bidirectional fan 111 and the heater 109 to work. The two-way fan 111 rotates forward to continuously supply air to the air duct between the cooling plate 107. The air fed into the air duct is heated by the heater 109 and becomes hot air, and then dissipates heat to the second through the ventilation holes 117 on the cooling plate 107. When the hot air is exhausted in the direction of the plate 107, the battery pack located there will be heated by the hot air during the process of exhausting the hot air from the added heat dissipation plate 107 to the direction of the second heat dissipation plate 107. In this way, the wind is continuously drawn into the air duct between the heat dissipation plates 107 to be heated, and the hot air obtained after being heated is continuously discharged to the second heat dissipation plate through the ventilation holes 117 on the heat dissipation plate 107, which not only improves the heating efficiency, but also improves the heating efficiency. It also effectively reduces the temperature difference in the battery box 101, avoiding that the temperature difference in the battery box is still relatively large when the heating preset temperature is partially reached in the battery box and the heater stops heating. The thermal management device of the battery pack of the present application creatively solves the contradictory requirements of the prior art that the battery box needs a good heat dissipation structure and a heating and heat preservation structure, and ensures that the battery pack in the battery system can be charged and discharged in a suitable environment. , which improves the cycle life of the battery pack and reduces various safety risks caused by high and low temperature.

To sum up, during cooling, the present application controls the temperature rise and temperature difference through the arrangement of the radiating components and the structural arrangement of optimized thermal management, so as to ensure effective and good air circulation inside the battery box and the battery pack, and avoid heat accumulation The resulting temperature rises, and the temperature difference between different parts inside is greatly reduced; during heating, the battery pack is heated and the entire battery box is kept warm through the arrangement of heating devices and the structural arrangement of thermal management. The heat dissipation structure of the present application adopts heat conduction and heat isolation type internal air duct circulation heat dissipation, which solves the problem of conflict and contradiction between the waterproof level such as IP67 and the heat dissipation structure, and solves the problem of using densely arranged and large number of small heating films. Compared with the traditional liquid-cooled heat-dissipation structure, the structure and process of the heat-dissipation structure of the present application are simplified, and the problems of complex liquid-cooled heat-dissipation structure, high manufacturing process cost and difficult modular assembly are solved. , and there is no safety problem of liquid cooling structure coolant leakage, and it has a selective heating function. The heating method of the present application has low power consumption, requires a small number of heating films, and the heater is not easily damaged. At the same time, the fan blows the wind directly to the surface of the PTC heater, which overcomes the characteristic that the heating stops automatically after the PTC reaches the rated temperature. , greatly improving the heating efficiency. The application adopts two layers of thermal management inside and outside, the internal heating cycle, when heating, the heat insulation film prevents the heat from dissipating; the external heat dissipation cycle, when the heat is circulated in the outer layer, the heat insulation film prevents the heat from entering the inner battery pack. In this way, the structure of sharing heating and cooling between the inner and outer layers ensures the strict sealing characteristics required for heating and heat preservation. At the same time, the independent heat dissipation layer ensures the characteristics of heat dissipation for cooling, and the heat insulation film effectively prevents heat from returning to the inner layer. In the battery pack, the contradiction between the two functions of heating and cooling at the same time is solved. It should be noted that, in an embodiment, the inner layer here refers to the space enclosed by the first heat dissipation plate 103 , the second heat dissipation plate 105 and the additional heat dissipation plate 107 in the battery box 101 , and the outer layer refers to the first heat dissipation plate 103 , the second heat dissipation plate 105 and the additional heat dissipation plate 107 . A heat dissipation plate 103, a second heat dissipation plate 105 and the outer protrusion of the inner wall of the battery box 101 form a relatively closed air duct.

The above specific examples are used to illustrate the present invention, which are only used to help understand the present invention, and are not intended to limit the present invention. For those skilled in the art, according to the idea of the present invention, the above-mentioned specific embodiments can be changed.

Claims (9)

1. A thermal management device for a battery pack, comprising: a battery box, the inner wall circumference of the battery box bulges outwards; Two first radiating plates, which are respectively fixed on a pair of opposite inner walls in the battery box, and form air ducts with the outer protrusions on the inner walls; wherein, each first radiating plate is provided with a two-way fan ; Two second radiating plates, which are respectively fixed on another pair of opposite inner walls in the battery box, and form air ducts with the outer protrusions on the inner wall; wherein, each second radiating plate is provided with several A cooling fan; wherein the air duct formed by the first cooling plate and the inner wall of the battery box is in communication with the air channel formed by the second cooling plate and the inner wall of the battery box; Two pieces of heat-dissipating plates, the two pieces of heat-dissipating plates are arranged in parallel at a certain distance to form air ducts, which are both parallel to the second heat-dissipating plate and fixed to the battery box or the first heat-dissipating plate, wherein the The two ends of the added radiator plate are respectively arranged at the two-way fans of the two first radiator plates, so that the air duct formed by the two pieces of heat-dissipating plates can receive the air supply or exhaust of the two-way fan; A number of ventilation holes are arranged on the heat dissipation plate; the air ducts formed by two of them plus the heat dissipation plate are in communication with the air channel formed by the first heat dissipation plate and the inner wall of the battery box; a heater, which is arranged on the opposite side of the heat-dissipating plate; A battery management circuit, which is electrically connected to the bidirectional fan, the cooling fan and the heater, respectively, is used to control the operation of the bidirectional fan, the cooling fan and the heater. 2 . The thermal management device for a battery pack according to claim 1 , wherein the first heat dissipation plate and/or the second heat dissipation plate is provided with fins on the side facing the inner wall of the battery box; and/or the Fins are arranged on the opposite side of the heat dissipation plate. 3 . The thermal management device for a battery pack according to claim 2 , wherein the distance from the top plane of the fins on the first heat dissipation plate to the bidirectional fan is at least 5 mm, and the distance between the top plane of the fins on the second heat dissipation plate and the bidirectional fan is at least 5 mm. 4 . The distance from the top plane of the fins to the cooling fan should be at least 8 mm. 4 . The thermal management device of the battery pack according to claim 1 , wherein the bidirectional fan is arranged in the middle of the first heat dissipation plate. 5 . 5 . The thermal management device for a battery pack according to claim 1 , wherein the two ends of the heat-dissipating plate are respectively disposed at the center of the two-way fan of the two first heat-dissipating plates, so that the heat-dissipating plate is added and the heat-dissipating plate is heated. 6 . The air ducts formed between the panels receive the maximum supply and exhaust air volume from the bidirectional fans. 6 . The thermal management device of the battery pack according to claim 1 , wherein each second heat dissipation plate is symmetrically provided with two heat dissipation fans. 7 . 7 . The thermal management device of the battery pack according to claim 1 or 6 , further comprising an insulating wind shield arranged on the periphery of the cooling fan on the second cooling plate. 8 . 8. The thermal management device for a battery pack according to claim 1, wherein the heater is a PTC heater. 9 . The thermal management device for a battery pack according to claim 1 or 8 , wherein the heater is fixed on the heat-dissipating plate by pouring thermally conductive silica gel. 10 .

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