Heat dissipation structure of electric vehicle power battery pack using immersion cooling

Abstract

The present invention discloses a heat dissipation structure of a power battery pack of an electric vehicle utilizing immersion cooling to dissipate heat, which comprises a box body, a battery box, a liquid inlet conduit, a reflux conduit, a refrigerant source and a power pump; the battery pack is inserted into a battery accommodating cavity of the battery box, and heat is generated when the battery is working, and the heat is conducted to the battery box; the power pump is turned on, and the power pump pumps refrigerant from the refrigerant source into the box body through the liquid inlet conduit, and the refrigerant directly immerses the battery box, and heat is dissipated from the battery box into the refrigerant, and then the refrigerant with heat flows back from the box body to the refrigerant source through the reflux conduit, thereby taking away the heat generated by the battery, thereby reducing the temperature of the battery; the structure has the characteristics of good heat dissipation performance.

Description

Technical Field

[0001] The invention relates to a heat dissipation structure of a power battery pack of an electric vehicle utilizing immersion cooling to dissipate heat. Background Art

[0002] In recent years, the energy crisis has worsened, and all countries have been committed to the development of clean energy vehicles, especially electric vehicles, which have made rapid progress. Lithium batteries are regarded as the best choice for electric vehicle power batteries due to their high single-cell voltage, light weight, small size, high specific energy, long cycle life, low self-discharge rate, no memory effect during charging and discharging, and are green, environmentally friendly, and pollution-free.

[0003] However, lithium batteries still have some disadvantages. For example, a large amount of heat is generated during rapid charging and discharging, causing the battery temperature to rise. The performance of lithium batteries decreases significantly with the increase in temperature. If they work in a high temperature environment for a long time, the battery life will be seriously reduced, and even battery leakage and thermal runaway may occur. In severe cases, electric vehicles may spontaneously combust. Existing heat dissipation technologies on the market, such as external air cooling and water cooling, are difficult to meet the heat dissipation requirements of batteries. Summary of the invention

[0004] The object of the present invention is to provide a heat dissipation structure of an electric vehicle power battery pack using immersion cooling to dissipate heat, so as to solve one or more of the above-mentioned problems in the prior art.

[0005] According to one aspect of the present invention, there is provided a heat dissipation structure for a power battery pack of an electric vehicle utilizing immersion cooling for heat dissipation, the heat dissipation structure comprising a housing, a battery box, a liquid inlet duct, a return duct, a refrigerant source and a power pump; wherein a battery accommodating cavity is provided on the battery box, and the battery box is accommodated in the housing; the liquid inlet duct and the return duct are both conductively connected to the interior of the housing, and the liquid inlet duct is connected to the power pump, the power pump is connected to the refrigerant source, and the return duct is connected to the refrigerant source.

[0006] In this way, when working, the battery pack is inserted into the battery receiving cavity of the battery box. The battery will generate heat when working, and the heat will be conducted to the battery box. The power pump is turned on, and the power pump pumps the refrigerant from the refrigerant source into the box through the liquid inlet pipe. The refrigerant directly immerses the battery box, and the heat is dissipated from the battery box into the refrigerant. Then the refrigerant with heat flows back from the box to the refrigerant source through the return pipe, thereby taking away the heat generated by the battery, thereby reducing the temperature of the battery; it has the characteristics of good heat dissipation performance.

[0007] In some embodiments, the battery box is provided with a plurality of battery accommodating cavities, and a through heat dissipation groove is provided between two adjacent battery accommodating cavities on the battery box.

[0008] In this way, a battery pack consisting of multiple batteries can be accommodated in the battery box, thereby increasing the capacity of the present invention; at the same time, by opening a through heat dissipation groove between two adjacent battery accommodating cavities on the battery box, the contact area between the battery box and the refrigerant is increased, that is, the heat dissipation area of ​​the battery box is increased, and the heat dissipated by the battery can be dissipated to the refrigerant more quickly through the side walls of the through heat dissipation groove.

[0009] In some embodiments, the inlet of the liquid inlet conduit extending into the box body and the outlet of the return conduit extending into the box body are respectively arranged on both sides of the battery box, the inlet is aligned with the first end of the through-heat dissipation groove, and the outlet is aligned with the second end of the through-heat dissipation groove.

[0010] In this way, when the refrigerant is pumped into the box from the inlet, the refrigerant enters from the first end of the through-heat sink, flows out from the second end of the through-heat sink after absorbing the heat, and then flows out directly from the outlet to the outside of the box, so that the refrigerant with waste heat will not accumulate in the box, further enhancing the heat dissipation effect of the present invention.

[0011] In some embodiments, a radiator is further included. The radiator is configured as a columnar body. A through-flow pipe is opened in the middle of the radiator. Both ends of the through-flow pipe are respectively connected to the return pipe and the refrigerant source.

[0012] In this way, after the refrigerant with waste heat flows out of the box, it is dissipated through the radiator, and after the waste heat is dissipated into the atmosphere, it flows back to the refrigerant source, thus achieving the function of heat dissipation.

[0013] In some embodiments, a plurality of heat dissipation fins are disposed on the outer periphery of the heat sink.

[0014] In this way, by providing a plurality of cooling fins on the periphery of the radiator, the contact area between the radiator and the refrigerant is increased, that is, the heat dissipation area of ​​the radiator is increased, and the waste heat can be dissipated into the refrigerant more quickly through the cooling fins. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of a heat dissipation structure of a power battery pack of an electric vehicle using immersion cooling according to an embodiment of the present invention;

[0016] Figure 2 for Figure 1 Another perspective structural schematic diagram of the structure shown;

[0017] Figure 3 A schematic diagram of a radiator in a heat dissipation structure of a power battery pack of an electric vehicle utilizing immersion cooling to dissipate heat according to an embodiment of the present invention.

[0018] Figure Number:

[0019] 1-battery box, 11-battery accommodating cavity, 12-through heat dissipation slot, 2-heat dissipation fins, 3-radiator, 31-through circulation pipeline DETAILED DESCRIPTION

[0020] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0021] Figure 1 The structure of a heat dissipation structure of an electric vehicle power battery pack using immersion cooling according to an embodiment of the present invention is schematically shown.

[0022] like Figure 1 and Figure 2 As shown, the heat dissipation structure of the electric vehicle power battery pack using immersion cooling includes a box body, a battery box 1, a liquid inlet conduit, a return conduit, a refrigerant source and a power pump; wherein, a battery accommodating cavity 11 is opened on the battery box 1, and the battery box 1 is accommodated in the box body; the liquid inlet conduit and the return conduit are both connected to the interior of the box body, and the liquid inlet conduit is connected to the power pump, the power pump is connected to the refrigerant source, and the return conduit is connected to the refrigerant source. In this embodiment, the refrigerant in the refrigerant source is transformer oil, the main components of which are alkanes, cycloalkane saturated hydrocarbons, and aromatic unsaturated hydrocarbon compounds, with a relative density of 0.895 and a freezing point of <-45°C; the specific heat capacity is 0.5k / (g*°C), the kinematic viscosity (50°C) ≤9.6×10-6m2 / s, and the flow rate has a good heat dissipation effect when it is between 1.5m / s and 4.7m / s; the good insulation effect can avoid short circuit between the two poles of the battery; if an arc is generated due to poor contact between the two poles of the battery, the transformer oil can absorb a large amount of heat generated by the arc and vaporize, thereby improving the arc extinguishing performance of the medium and extinguishing the arc quickly; 5% flame retardant is added to the transformer oil to avoid overheating and combustion of the battery.

[0023] Working principle: Insert the battery pack into the battery accommodating cavity 11 of the battery box 1. The battery will generate heat when working, and the heat will be conducted to the battery box 1. Turn on the power pump, and the power pump pumps the refrigerant from the refrigerant source into the box through the liquid inlet pipe. The refrigerant directly immerses the battery box 1, and the heat is dissipated from the battery box 1 into the refrigerant. Then the refrigerant with heat flows back from the box to the refrigerant source through the return pipe, thereby taking away the heat generated by the battery, thereby reducing the temperature of the battery; it has the characteristics of good heat dissipation performance.

[0024] When the present invention is applied in the field of electric vehicle power heat dissipation, the present invention has the following advantages over the prior art: 1. An efficient automotive power battery thermal management system. This project realizes battery temperature control based on transformer oil. Compared with traditional air cooling, it does not require a high-power fan, and the battery box 1 is installed at the vehicle vent to reduce power loss, thus having higher efficiency and being able to save power battery energy. 2. Transformer oil has good thermodynamic properties, flows mainly in a turbulent manner on the battery surface, and has a high convective heat transfer coefficient; transformer oil has good insulation properties, and adding flame retardants gives it a certain flame retardant effect.

[0025] In this embodiment, the battery box 1 is provided with a plurality of battery accommodating cavities 11, and a through heat dissipation slot 12 is provided between two adjacent battery accommodating cavities 11 on the battery box 1. In this way, a battery pack consisting of a plurality of batteries can be accommodated in the battery box 1, thereby increasing the capacity of the present invention; at the same time, by providing the through heat dissipation slot 12 between two adjacent battery accommodating cavities 11 on the battery box 1, the contact area between the battery box 1 and the refrigerant is increased, that is, the heat dissipation area of ​​the battery box 1 is increased, and the heat dissipated by the battery can be dissipated to the refrigerant more quickly through the side walls of the through heat dissipation slot 12.

[0026] In this embodiment, the inlet of the liquid inlet conduit extending into the box body and the outlet of the return conduit extending into the box body are respectively arranged on both sides of the battery box 1, the inlet is aligned with the first end of the through-heat dissipation slot 12, and the outlet is aligned with the second end of the through-heat dissipation slot 12. In this way, when the refrigerant is pumped into the box body from the inlet, the refrigerant enters from the first end of the through-heat dissipation slot 12, flows out from the second end of the through-heat dissipation slot 12 after absorbing heat, and then flows out directly from the outlet to the outside of the box body, so that the refrigerant with waste heat will not accumulate in the box body, further enhancing the heat dissipation effect of the present invention.

[0027] In this embodiment, an auxiliary heat dissipation device is also included, which includes a temperature collection unit and a flow rate control unit. The surface of the power pump is insulated. When the temperature collected by the thermal sensor located on the surface of the battery is too high, the power pump starts to work and controls the flow rate of the transformer oil according to the specific temperature, thereby strengthening the heat dissipation of the transformer oil and the fins and controlling the temperature within a reasonable range.

[0028] like Figure 3 As shown, in this embodiment, a radiator 3 is also included. The radiator 3 is set in a columnar shape. A through-flow pipe 31 is also opened in the middle of the radiator 3. The two ends of the through-flow pipe 31 are respectively connected to the return pipe and the refrigerant source. In this way, after the refrigerant with waste heat flows out of the box, it passes through the radiator 3 to dissipate the waste heat, dissipates the waste heat into the atmosphere, and then flows back to the refrigerant source, playing a heat dissipation function.

[0029] In this embodiment, a plurality of heat dissipation fins 2 are provided on the periphery of the radiator 3. Thus, by providing a plurality of heat dissipation fins 2 on the periphery of the radiator 3, the contact area between the radiator 3 and the refrigerant is increased, that is, the heat dissipation area of ​​the radiator 3 is increased, and the waste heat can be dissipated to the refrigerant more quickly through the heat dissipation fins 2.

[0030] The above is only one embodiment of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the inventive concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. An electric vehicle power battery pack heat dissipation structure using immersion cooling, characterized in that: It includes a box body, a battery box, a liquid inlet conduit, a return conduit, a refrigerant source and a power pump; The battery box is provided with a battery accommodating cavity, and the battery box is accommodated in the box; the liquid inlet conduit and the return conduit are both conductively connected to the interior of the box, and the liquid inlet conduit is connected to the power pump, the power pump is connected to the refrigerant source, and the return conduit is connected to the refrigerant source; The battery box is provided with a plurality of battery accommodating cavities, and a through heat dissipation groove is provided between two adjacent battery accommodating cavities on the battery box; The inlet of the liquid inlet conduit extending into the box body and the outlet of the return conduit extending into the box body are respectively arranged on both sides of the battery box, the inlet is aligned with the first end of the through heat dissipation slot, and the outlet is aligned with the second end of the through heat dissipation slot; The refrigerant in the refrigerant source is transformer oil, the main components of which are alkanes, cycloalkanes, saturated hydrocarbons, and aromatic unsaturated hydrocarbon compounds, with a relative density of 0.895, a freezing point of <-45°C, a specific heat capacity of 0.5 kJ / (g.°C), and a kinematic viscosity of ≤9.6×10 at 50°C. -6 m 2 / s, and has good heat dissipation effect when the flow rate is between 1.5m / s and 4.7m / s; has good insulation effect, which can avoid short circuit between the two poles of the battery; if an arc is generated due to poor contact between the two poles of the battery, the transformer oil can absorb a large amount of heat generated by the arc and vaporize, thereby improving the arc extinguishing performance of the medium and extinguishing the arc quickly; 5% flame retardant is added to the transformer oil to avoid overheating and combustion of the battery.

2. The heat dissipation structure of the electric vehicle power battery pack using immersion cooling according to claim 1 is characterized in that: It also includes a radiator, which is configured as a columnar body. A through-flow pipe is provided in the middle of the radiator, and two ends of the through-flow pipe are respectively connected to the return pipe and the refrigerant source.

3. The heat dissipation structure of electric vehicle power battery pack using immersion cooling according to claim 2 is characterized in that: A plurality of heat dissipation fins are arranged on the outer periphery of the heat sink.

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