WO2017215159A1

WO2017215159A1 - Cooling system of working medium contact type for power battery and working method thereof

Info

Publication number: WO2017215159A1
Application number: PCT/CN2016/102102
Authority: WO
Inventors: 王伟
Original assignee: 广东合一新材料研究院有限公司
Priority date: 2016-06-16
Filing date: 2016-10-14
Publication date: 2017-12-21
Also published as: CN105977572B; CN105977572A

Abstract

Disclosed is a cooling system of a working medium contact type for a power battery. A working medium box is filled with an insulating liquid heat-conducting working medium; a working medium pump is sunk into the insulating liquid heat-conducting working medium; a filter is mounted at an inlet of the working medium pump; the working medium pump is connected to a main spray pipe; multiple branch spray pipes are connected to the main spray pipe in parallel; each of the branch spray pipes is provided with multiple nozzles; the nozzles are directed at a high-power battery pack. The branch spray pipes and the main spray pipe form a cage-shaped frame. The high-power battery pack is disposed in the cage-shaped frame, and the branch spray pipes are distributed on side faces and the upper part thereof so as to form a relatively open spray structure. The insulating liquid heat-conducting working medium is a non-polar substance and is free of phase changes in a spray process. Further disclosed is a working method of the cooling system of a working medium contact type for a power battery. The heat dissipation structure of the present invention is rational and the heat dissipation efficiency is high.

Description

Working battery contact cooling system for power battery and working method thereof

Technical field

The invention relates to the technical field of cooling of a power battery, and in particular to a working fluid contact cooling system for a power battery and a working method thereof.

Background technique

With the implementation of the new energy strategy, electric vehicles are being widely used. Lithium-ion power batteries are well used for their excellent power output characteristics and long life. However, the performance of high-capacity, high-power lithium-ion batteries is sensitive to temperature changes. And in a limited space, the number of batteries used is large. When the vehicle is running under different driving conditions, the battery will discharge at different rates, generate a large amount of heat at different heat generation rates, plus time accumulation and space influence will generate uneven heat accumulation, resulting in complex and variable battery operating environment temperature. . The low temperature environment below 0 °C is easy to cause battery damage during the starting process of electrical components; while the long-term high temperature environment will reduce the battery capacity. If accumulated for a long time, some batteries will overcharge and over discharge, which will affect the battery life and performance. It is prone to safety hazards such as explosion and burning.

Therefore, the heat generated by the high-power power battery during operation must be dissipated through the cooling device to ensure that the battery temperature is within the safe working temperature range, and avoiding the safety hazard caused by over-temperature.

The existing power battery cooling device has the following technical defects:

(1) Indirect heat transfer using air as a medium: 1 The cooling device uses forced convection air cooling, and the fan/fan is forced to dissipate the ambient air convection, and the heat conduction performance of the air is lower than that of the liquid working medium, and the heat dissipation efficiency is low. 2 put higher requirements on the cleanliness of the air.

(2) Providing a heat pipe in the battery system for indirect heat transfer: 1 relying on the liquid medium circulating in the heat pipe to exchange heat with the heat generating battery. Although this method uses liquid working medium for heat transfer, the working medium and the battery are still For indirect contact, there are thermal resistance, flow resistance and flow unevenness, and the heat dissipation efficiency is low. 2 It is necessary to design a heat pipe loop according to the arrangement of the battery. The heat pipe loop is difficult to arrange and takes up a large space.

Summary of the invention

In order to solve the above technical problems, the present invention provides a working fluid contact cooling system for a power battery, which has a reasonable heat dissipation structure and high heat dissipation efficiency.

The invention also provides a method of operating a working fluid contact cooling system for a power battery.

The solution to solve the above technical problem of the present invention is as follows:

Power battery contact cooling system, including high-power battery pack composed of several single cells, insulating liquid heat transfer medium, nozzle, spray branch pipe, spray main pipe, working fluid pump, filter and working tank ,

The working medium box is filled with insulating liquid heat-conducting working medium, the working medium pump is suspended in the insulating liquid heat-conducting working medium, the filter is installed at the inlet of the working medium pump, the working medium pump is connected with the spraying main pipe, and the plurality of spraying branch pipes are connected in parallel to the spraying main pipe. Each spray branch pipe is provided with a plurality of nozzles facing the high power battery pack;

The spray branch pipe and the spray main pipe form a cage frame, and the high-power battery pack is placed in the cage frame, and the spray branch pipe is distributed on the side and the upper side to form a relatively open spray structure;

The insulating liquid thermal conductive working substance is a non-polar substance, and the insulating liquid thermal conductive working medium has no phase change during the spraying process.

The working tank can be set up with the following four cooling cycle structures:

1. The working box is provided with a natural convection cooling structure of the air: the outer side of the working box is provided with heat dissipating fins.

2. The working tank is provided with an air forced convection cooling structure: the outer side of the working box is provided with heat dissipating fins, and a plurality of fans are arranged to blast the heat dissipating fins.

3. The working tank is provided with a water circulation cooling device: the evaporation working end of the water circulation cooling device is immersed in the working medium tank, and the water circulation cooling device has a water pump in the pipeline, and the heat discharging end of the water circulation cooling device is blown by the fan.

4. The working tank is provided with a compression refrigeration cycle cooling device: the evaporator of the compression refrigeration cycle cooling device is immersed in the working tank, and the outer condenser is cooled.

In the above working method of the working fluid contact cooling system of the power battery, the working fluid pump is started, the insulating liquid heat conductive working medium passes through the filter and enters the working medium pump, and the working medium pump transports the insulating liquid heat conductive medium. To the spray main pipe, the spray main pipe distributes the insulating liquid thermal conductive working substance to each spray branch pipe, and the insulating liquid thermal conductive working medium sprayed from the nozzle directly sprays to the periphery and above of the high-power battery pack, and the heat of the high-power battery pack passes. The insulating liquid heat-conducting medium is taken away, and the insulating liquid heat-conducting working medium is returned to the working medium box under gravity and cooled, so that the insulating liquid heat-conducting working medium continuously takes away the heat of the high-power battery pack.

The present invention has the following advantages over the prior art:

1. The spray branch pipe and the spray main pipe form a cage frame, and the high-power battery pack is placed in the cage frame, and the spray branch pipe is distributed on the side and the upper side to form a relatively open spray structure, and the insulating liquid heat conductive medium is directly Contact with the heating surface of the high-power battery pack that needs heat dissipation to conduct heat, reduce contact thermal resistance, without any intermediate medium and heat transfer conversion, and improve heat transfer efficiency.

2. The insulating liquid thermal conductive working substance is a non-polar substance. During the spraying process, the insulating liquid thermal conductive working medium has no phase change, and the sprayed insulating liquid thermal conductive working medium forms an atomized liquid film on the surface of the high-power battery pack, and the atomized liquid film Thermal conduction has a combination of excellent heat transfer and flow such as small flow rate, large temperature difference, high heat transfer coefficient, and high heat flux density.

3. Under the same ambient temperature, the direct contact cooling heat dissipation temperature difference can be controlled. Compared with the non-direct contact heat transfer mode, the surface temperature of the high power battery pack can be further reduced, which helps to improve the working life of the high power battery pack and reliability.

4, using spray-type heat dissipation, the effective contact area (heat exchange area) of the insulating liquid heat-conducting medium and the high-power battery pack heating surface will increase, so the theoretical heat transfer efficiency will increase (the heat exchange amount is proportional to the area), the insulating liquid The heat transfer medium has a higher effective utilization rate.

5. There is no phase change in the thermal conductivity of the insulating liquid during the spraying process. Therefore, the system circulation does not require the gas phase recovery equipment, and only the common filter is needed to filter the impurities generated by the working medium in the relatively open cycle process. Sexuality and reliability are higher.

6. Insulating liquid heat transfer working medium is non-polar substance, which will not affect the electronics, electrical equipment and circuit, and will not damage the hardware.

7. The spray pipe has simple structure and low power consumption; the nozzle parts manufacturing technology is mature and the reliability is high. The simpler the heat transfer process and structure, the higher its reliability and controllability.

8. Insulating liquid heat transfer working fluid as a liquid heat exchange method, its heat conduction performance is generally better than the use of forced air convection, and compared with the traditional forced convection air cooling system requires fresh air unit and some complex architecture design, liquid cooling technology architecture design requirements It is less self-contained, and the structure that directly contacts the spray can be simpler, thereby saving costs and extending the life of the device.

DRAWINGS

1 is a schematic view showing the structure of a working fluid contact cooling system of a power battery of Embodiment 1.

Fig. 2 is a structural view showing a shower main pipe and a shower branch pipe of the first embodiment;

3 is a schematic structural view of a working fluid contact cooling system of a power battery of Embodiment 2.

Fig. 4 is a structural view showing a shower main pipe and a spray branch pipe of the second embodiment.

Fig. 5 is a heat dissipation structure of the working tank of the third embodiment.

Fig. 6 is a heat dissipation structure of the working tank of the fourth embodiment.

detailed description

The invention will now be further described with reference to the accompanying drawings and embodiments.

Example 1:

The working fluid contact cooling system of the power battery shown in FIG. 1 comprises a high power battery pack composed of a plurality of single cells, an insulating liquid heat transfer medium 2, a nozzle 3, a spray branch pipe 4, and a spray manifold 5 , working fluid pump 6, filter 7 and working tank 8,

The filter 7 ensures the purity of the insulating liquid heat-conducting medium 2, prevents damage of the working fluid pump 6 by impurities and clogging of the nozzle 3.

Insulating liquid heat transfer medium 2 must use a good thermal conductivity liquid working fluid, such as various types of transformer oil, heat transfer oil, etc., to ensure the insulation of the working medium, to avoid contact with the high-power battery pack 1 conductive, resulting in battery damage and The system is scrapped. The insulating liquid thermal conductive medium 2 generally has a high thermal conductivity, and can be directly contacted with the heat-generating high-power battery pack 1 by spraying, thereby enabling efficient heat dissipation to the high-power battery pack 1.

The nozzle 3 needs to use materials with excellent insulation and engineering strength.

The working medium box 8 is filled with an insulating liquid heat-conducting working medium 2, the working medium pump 6 is suspended in the insulating liquid heat-conducting working medium 2, the filter 7 is installed at the inlet of the working medium pump 6, and the working medium pump 6 is connected to the spraying main pipe 5, a plurality of The spray branch 4 is connected in parallel to the spray manifold 5, and each spray branch 4 is provided with a plurality of nozzles 3 facing the high-power battery pack 1.

The insulating liquid heat transfer medium 2 is a non-polar substance, and the insulating liquid heat transfer medium 2 has no phase change during the spraying process.

As shown in FIG. 2, the spray branch pipe 4 and the spray pipe 5 form a cage frame, and the high-power battery pack 1 is placed in the cage frame, and the spray branch pipe 4 is distributed on the side and the upper side to form a relatively open spray. structure.

The working box 8 is provided with an air natural convection cooling structure: the outer side of the working medium box 8 is provided with a heat dissipating fin 9. The natural convection of the ambient air alone relies on the insulating liquid heat transfer medium 2 carrying the heat of the battery to cool down in the working tank 8 through the heat dissipating fins 9 and the environment. This cooling method has the outstanding advantage that the cooling part does not use any power consuming appliances or mechanical parts; it can be used as long as the environmental conditions satisfy the basic heat dissipation temperature difference and natural convection conditions. The insulating liquid heat transfer medium 2 in the working tank 8 is continuously cooled to ensure the effective heat exchange temperature difference between the insulating liquid heat conductive medium 2 and the high power battery pack 1 to effectively cool the high power battery pack 1.

In the above working method of the working fluid contact cooling system of the power battery, the working fluid pump 6 is started, and the insulating liquid thermal conductive medium 2 enters the working fluid pump 6 through the filter 7, and the working fluid pump 6 heats the insulating liquid 2 It is sent to the spray main pipe 5, and the spray main pipe 5 distributes the insulating liquid heat transfer medium 2 to each spray branch pipe 4, and the insulating liquid heat transfer medium 2 sprayed from the nozzle 3 is directly sprayed to the periphery and above of the high power battery pack 1. The heat of the high-power battery pack 1 is taken away by the insulating liquid heat transfer medium 2, and the insulating liquid heat transfer medium 2 is returned to the working tank 8 under gravity and cooled, so that the insulating liquid heat transfer medium 2 is continuously high. The heat of the power battery pack 1 is taken away.

Example 2:

Figure 3 shows another working fluid contact cooling system for a power battery. The working box 8 is provided with an air forced convection cooling structure: the outer side of the working box 8 is provided with a heat dissipating fin 9 and a plurality of fans are arranged 10 blasts the heat radiating fins 9. The air is convected under the influence of external force, and the fresh air with lower temperature continuously circulates into the heat transfer medium 2 of the insulating liquid to realize the cooling of the insulating liquid heat transfer medium 2 .

As shown in Fig. 4, the spray branch pipe 4 and the spray pipe 5 form a rectangular frame.

Example 3:

As shown in FIG. 5, the working tank 8 is provided with a water circulation cooling device: the evaporation working end 11 of the water circulation cooling device is immersed in the working tank 8, and the water circulation cooling device is provided with a water pump 13 in the pipeline, and the heat dissipation end 12 of the water circulation cooling device passes The fan 10 performs blasting to achieve cooling of the high-temperature insulating liquid heat transfer medium 2 in the working fluid tank 8 by heat exchange, and the water of the evaporation working end 11 carries the heat of the insulating liquid heat-conductive working medium 2 to the heat-dissipating end 12 After the heat is dissipated, the heat transfer of the insulating liquid heat transfer medium 2 is continued by the water pump 13 circulation.

Example 4:

As shown in Fig. 6, the working tank 8 is provided with a compression refrigeration cycle cooling device: the evaporator 14 of the compression refrigeration cycle cooling device is immersed in the working tank 8, and the outer condenser 15 dissipates heat. The evaporator 14 is heat-exchanged with the high-temperature insulating liquid heat transfer medium 2, and then cooled and recirculated in the outer condenser 15.

The above is a preferred embodiment of the present invention, but the embodiments of the present invention are not limited to the above, and any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and scope of the present invention. Equivalent replacement means are included in the scope of protection of the present invention.

Claims

The working fluid contact cooling system of the power battery is characterized in that it comprises a high-power battery pack composed of a plurality of single cells, an insulating liquid thermal conductive working fluid, a nozzle, a spray branch pipe, a spray main pipe, a working fluid pump, and a filter. And the work box,

The working medium tank is filled with an insulating liquid heat-conducting working medium, the working medium pump is suspended in the insulating liquid heat-conductive working medium, the filter is installed at the inlet of the working medium pump, the working medium pump is connected to the spray main pipe, and the plurality of spray branch pipes are connected in parallel a shower main pipe, each spray branch pipe is provided with a plurality of nozzles, and the nozzles face the high power battery pack;

The spray branch pipe and the spray main pipe form a cage frame, and the high-power battery pack is placed in the cage frame, and the spray branch pipe is distributed on the side and the upper side to form a relatively open spray structure;

The insulating liquid thermal conductive working substance is a non-polar substance, and the insulating liquid thermal conductive working medium has no phase change during the spraying process.
The working medium contact cooling system for a power battery according to claim 1, wherein the working tank is provided with a natural convection cooling structure of the air: a heat dissipating fin is disposed outside the working chamber.
The working fluid contact cooling system for a power battery according to claim 1, wherein the working fluid tank is provided with an air forced convection cooling structure: a heat dissipating fin is disposed outside the working medium box, and a plurality of fan pairs are disposed The heat radiating fins are blasted.
The working medium contact cooling system for a power battery according to claim 1, wherein the working tank is provided with a water circulation cooling device: the evaporation working end of the water circulation cooling device is immersed in the working medium tank, and the water circulation cooling device tube The road is provided with a water pump, and the heat radiating end of the water circulation cooling device is blown by a fan.
The working medium contact cooling system for a power battery according to claim 1, wherein the working tank is provided with a compression refrigeration cycle cooling device: the evaporator of the compression refrigeration cycle cooling device is immersed in the working tank The outside condenser dissipates heat.
The working method of the working fluid contact cooling system of the power battery according to claim 1, wherein the working fluid pump is started, the insulating liquid heat conductive working medium passes through the filter and enters the working fluid pump, and the working fluid pump applies the insulating liquid. The heat transfer working medium is transported to the spray main pipe, and the spray main pipe distributes the insulating liquid heat conductive working substance to each spray branch pipe, and the insulating liquid heat conductive working medium sprayed from the nozzle directly sprays to the high power battery Around and above the group, the heat of the high-power battery pack is taken away by the insulating liquid heat-conducting working medium, and the insulating liquid heat-conducting working fluid is returned to the working tank under the action of gravity and cooled, so that the thermal conductivity of the insulating liquid is continuously high. The heat of the power battery pack is taken away.