阅读说明：本技术 一种干湿分离的锂电池包热管理系统及方法 (Dry-wet separated lithium battery pack heat management system and method ) 是由 赵耀华 徐红霞 于 2019-11-04 设计创作，主要内容包括：一种干湿分离的锂电池包热管理系统及方法,包括电池包内部的一层或多层电池和/或电池模组、电池包外壳和液冷板管换热器,所述电池和/或电池模组上表面和/或下表面贴合微热管阵列,贴合所述电池和/或电池模组表面的部分为蒸发段,所述微热管阵列至少有一端伸出所述电池和/或电池模组的表面,伸出部分作为冷凝段与电池包外壳贴合；所述电池包外壳围绕所述电池包且为封闭结构,至少在对应所述冷凝段处为导热隔板；所述液冷板管换热器的基板密封,并与电池和/或电池模组完全物理隔离；所述液冷板管换热器至少对应贴合所述导热隔板的外表面,且与电池包外部的制冷系统连接。具有散热效率高,干湿分离、防止漏液的优势。(A dry-wet separated lithium battery pack thermal management system and method comprises one or more layers of batteries and/or battery modules, a battery pack shell and a liquid cooling plate tube heat exchanger, wherein the batteries and/or the battery modules are arranged in a battery pack, the upper surface and/or the lower surface of each battery and/or battery module is/are attached to a micro heat pipe array, the part attached to the surface of each battery and/or battery module is an evaporation section, at least one end of the micro heat pipe array extends out of the surface of each battery and/or battery module, and the extending part serves as a condensation section and is attached to the battery pack shell; the battery pack shell surrounds the battery pack and is of a closed structure, and at least a heat conduction partition plate is arranged at the position corresponding to the condensation section; the base plate of the liquid cooling plate pipe heat exchanger is sealed and is completely and physically isolated from the battery and/or the battery module; the liquid cooling plate pipe heat exchanger is at least correspondingly attached to the outer surface of the heat conducting partition plate and is connected with a refrigerating system outside the battery pack. The dry-wet separation type heat dissipation device has the advantages of high heat dissipation efficiency, dry-wet separation and liquid leakage prevention.)

1. A dry-wet separated lithium battery pack thermal management system is characterized by comprising one or more layers of batteries and/or battery modules in a battery pack, a battery pack shell and a liquid cooling plate pipe heat exchanger,

the battery and/or the battery module is horizontal, the upper surface and/or the lower surface of the battery and/or the battery module is attached with the micro heat pipe array, the part of the micro heat pipe array attached with the surface of the battery and/or the battery module is an evaporation section, the length of the micro heat pipe array is at least larger than the span of the battery and/or the battery module on the layer covered by the micro heat pipe array in one direction, at least one end of the micro heat pipe array extends out of the surface of the battery and/or the battery module, and the extending part is attached with a battery pack shell as a condensation section;

the battery pack shell surrounds the battery pack and is of a closed structure, and the battery pack shell is at least provided with a heat-conducting partition plate at the position corresponding to the condensation section;

the base plate of the liquid cooling plate pipe heat exchanger is sealed and is completely and physically isolated from the battery and/or the battery module through the battery pack shell;

the liquid cooling plate pipe heat exchanger is at least correspondingly attached to the outer surface of the heat conducting partition plate, and the liquid cooling plate pipe heat exchanger is connected with a refrigerating system outside the battery pack.

2. The system according to claim 1, wherein the batteries and/or battery modules are stacked in multiple layers, each layer comprises multiple groups, each group comprises multiple groups, and each group has the surface to which the micro heat pipe array is attached.

3. The system according to claim 2, wherein the upper and lower surfaces of each group of the batteries and/or battery modules are attached to the micro heat pipe arrays, at least one micro heat pipe array is attached to each side surface, each micro heat pipe array has at least one end extending part bent in a direction perpendicular to the plane of the micro heat pipe array, the upward bent part of the micro heat pipe array located on the lower side is a condensation section attached to the heat-conducting partition plate for heat dissipation, and the downward bent part of the micro heat pipe array located on the upper side is an evaporation section attached to or connected with a heater for heating the batteries.

4. The system of claim 2, wherein at least one of the micro heat pipe arrays is attached to one of the upper and lower surfaces of each group of the batteries and/or battery modules, and the protruding portions of both ends are bent toward the same side and attached to the heat conductive spacer.

5. The system of claim 1, wherein the micro heat pipe array is a flat heat conductor with a porous structure formed by extruding a metal material, a plurality of micro heat pipes which are arranged side by side and are not communicated with each other and operate independently are arranged inside the micro heat pipe array, the hydraulic diameter of each micro heat pipe is 0.2-3.0mm, and the internal phase change working medium is a non-conductive medium.

6. The system of claim 1, wherein a compressible heat-conducting gasket is disposed between the micro heat pipe array and the battery and/or battery module.

7. The system of claim 1, wherein the lower surface of the micro heat pipe array is further provided with a heater.

8. The system of claim 3 or 7, further comprising an automatic control system and a cell temperature detection unit, wherein the automatic control system is connected to the cell temperature detection unit, the heater and the refrigeration system respectively.

9. A dry-wet separation lithium battery pack heat management method is characterized in that the heat management system according to any one of claims 1 to 8 is adopted, an evaporation section of a micro heat pipe array attached to the surface of a battery and/or a battery module absorbs heat of the battery and/or the battery module, the heat is conducted to a condensation section of an extending part, and then the heat is conducted to a liquid cooling plate pipe heat exchanger attached to the outer surface of a heat conduction partition plate and connected with a battery pack external refrigeration system through the heat conduction partition plate.

10. The method of claim 9, wherein when the detected temperature of the battery cell is higher than a first set value, the control system automatically starts the refrigeration system to drive the liquid cold plate and tube heat exchanger to start to dissipate heat from the battery cell; when the temperature of the battery core is lower than a first set value, the refrigerating system stops supplying cold to the liquid cooling plate pipe heat exchanger, when the temperature of the battery is lower than a second set temperature, the heater which is directly or indirectly contacted with the micro heat pipe array is heated, the battery is heated through the micro heat pipe array, and at the moment, the refrigerating system stops running.

Technical Field

The invention relates to a dry-wet separation battery pack heat management method and system, and belongs to the field of battery pack heat dissipation of electric automobiles.

Background

Thermal management of the lithium battery pack is critical not only to battery life, but also to battery safety.

The traditional battery pack heat management method, namely the air cooling technology, can not meet the requirement of the protection level of the lithium battery pack, and the great temperature difference between the battery core and the battery core is caused due to the great temperature difference of the inlet and the outlet of the air cooling system, so that the lithium battery is greatly damaged, and therefore, the use value is basically not available at present.

The traditional lithium battery pack heat management method with high protection level generally adopts a liquid cooling mode, a liquid cooling bottom plate adopted by most manufacturers at present only sets up a single liquid cooling plate at the bottom of a battery module, the single liquid cooling plate heat dissipation mode at the bottom of the battery module can cause great temperature difference inside a battery monomer, and the damage to a battery is great when the battery is rapidly charged and discharged and preheated at low temperature. Only tesla employs all battery full side surface liquid cooling mode. However, at present, the liquid cooling medium is directly cooled by antifreeze or refrigeration medium, and the latter is equivalent to a direct expansion evaporator. The direct expansion type cooling of the refrigerating medium has the advantages that due to the fact that the temperature of the refrigerating medium is too low, severe cold impact can be caused on the battery, the temperature difference inside the battery is extremely large, the battery is greatly damaged, and the direct expansion type cooling of the refrigerating medium basically has no practical value. The used antifreeze solution contains water, and for the liquid-cooled bottom plate with a plurality of welding parts, the welding parts are easy to damage in the using process, so that the antifreeze solution inside leaks; all sides are used for Tesla to the liquid cooling pipe, the welding port is located outside the battery pack, once impact occurs, the liquid cooling pipe between the battery cores is damaged, anti-freezing liquid leakage can be caused, the welding port is distributed on all sides, and the probability that the welding port is damaged is high. In either case, the leaked antifreeze may short-circuit the battery pack if it contacts the battery in the battery pack, resulting in a serious safety accident.

Disclosure of Invention

The invention provides a dry-wet separation lithium battery pack thermal management system and method, aiming at solving the problems of large potential safety hazard, low heat dissipation efficiency and large damage to a battery in the prior art.

The technical scheme of the invention is as follows:

a dry-wet separated lithium battery pack thermal management system is characterized by comprising one or more layers of batteries and/or battery modules in a battery pack, a battery pack shell and a liquid cooling plate pipe heat exchanger,

the battery and/or the battery module is horizontal, the upper surface and/or the lower surface of the battery and/or the battery module is attached with the micro heat pipe array, the part of the micro heat pipe array attached with the surface of the battery and/or the battery module is an evaporation section, the length of the micro heat pipe array is at least larger than the span of the battery and/or the battery module on the layer covered by the micro heat pipe array in one direction, at least one end of the micro heat pipe array extends out of the surface of the battery and/or the battery module, and the extending part is attached with a battery pack shell as a condensation section;

the battery pack shell surrounds the battery pack and is of a closed structure, and the battery pack shell is at least provided with a heat-conducting partition plate at the position corresponding to the condensation section;

the base plate of the liquid cooling plate pipe heat exchanger is sealed and is completely and physically isolated from the battery and/or the battery module through the battery pack shell;

the liquid cooling plate pipe heat exchanger is at least correspondingly attached to the outer surface of the heat conducting partition plate, and the liquid cooling plate pipe heat exchanger is connected with a refrigerating system outside the battery pack.

Preferably, the batteries and/or the battery modules are distributed in a multi-layer overlapping mode, each layer comprises a plurality of groups, each group comprises a plurality of groups, and the surface of each group is respectively attached to the micro heat pipe array.

The upper side surface and the lower side surface of the battery and/or the battery module are attached to the micro heat pipe arrays, at least one micro heat pipe array is attached to each side surface, each micro heat pipe array is provided with at least one end extending part, the extending parts are bent towards the vertical direction of the micro heat pipe array plane, the upward bending part of the micro heat pipe array located on the lower side is a condensation section, the condensation section is attached to the heat conduction partition plate and used for heat dissipation, the downward bending part of the micro heat pipe array located on the upper side is an evaporation section, and a heater is attached or connected to the evaporation section and used for heating the battery.

Preferably, one of the upper surface and the lower surface of each group of batteries and/or battery modules is attached to at least one micro heat pipe array, and the extending parts at the two ends are bent towards the same side and attached to the heat-conducting partition plate.

The preferable micro heat pipe array is a flat heat conductor which is formed by extruding a metal material and has a porous structure, a plurality of micro heat pipes which are arranged side by side, are not communicated with each other and operate independently are arranged in the micro heat pipe array, the hydraulic diameter of each micro heat pipe is only 0.2-3.0mm and is even smaller, and the internal phase change working medium is a non-conductive medium. And solid metal strips with the width of 3-10mm and the length same as that of the micro heat pipe array are reserved between the independent heat pipes along the length direction of the heat pipes according to the position size of the mounting holes and can be used for drilling the mounting holes.

Preferably, a compressible and deformable heat conduction gasket is arranged between the micro heat pipe array and the battery and/or the battery module.

Preferably, the base plate of the liquid cooling plate tube heat exchanger is connected or welded with the outer surface of the battery pack shell through a sealing ring, and the battery pack shell is of an IP67 grade.

Preferably, the base plate of the liquid cooling plate pipe heat exchanger is provided with a refrigerant inlet and a refrigerant outlet which are respectively connected with a refrigerating system.

Preferably, the lower surface of the micro heat pipe array is also provided with a heater, and the heater is preferably an electric heating film.

Preferably, the system also comprises an automatic control system and a cell temperature detection unit, wherein the automatic control system is respectively connected with the cell temperature detection unit, the heater and the refrigeration system.

The dry-wet separation type lithium battery pack heat management method is characterized in that the heat management system is adopted, an evaporation section of a micro heat pipe array attached to the surface of a battery and/or a battery module absorbs heat of the battery and/or the battery module, the heat is conducted to a condensation section of an extending part, and then the heat is conducted to a liquid cooling plate pipe heat exchanger attached to the outer surface of a heat conduction partition plate and connected with a battery pack external refrigeration system through the heat conduction partition plate.

When the detected temperature of the battery cell is higher than a first set value, the control system automatically starts the refrigerating system to drive the liquid cooling plate tube heat exchanger to start, so that heat dissipation is carried out on the battery cell; and when the temperature of the battery cell is lower than a first set value, the refrigerating system stops supplying cold to the liquid cooling plate pipe heat exchanger. When the temperature of the battery is lower than a second set temperature, the heater which is directly or indirectly contacted with the micro heat pipe array is heated, the battery is heated through the micro heat pipe array, and at the moment, the refrigeration system stops running.

The invention has the beneficial technical effects that:

the invention relates to a dry-wet separation battery pack heat management system, which is characterized in that a micro heat pipe array heat conductor is attached to the surface of a battery (electric core) or a battery module, heat is transmitted to a liquid cooling plate pipe heat exchanger through a heat conduction clapboard, the liquid cooling plate pipe heat exchanger is combined with a refrigeration system of an electric automobile to form a liquid cooling system, and the temperature of the electric core is managed in an indirect liquid cooling mode. On the one hand, the unilateral of little heat pipe array and every group electricity core or two side surface laminating, even be located inside electric core like this, its temperature also can be through the little heat pipe array with it laminating give the thermal baffle of its laminating in both ends effective conduction, and then the conduction is outside to the battery, then through the liquid cooling plate tube heat exchanger of being connected with electric automobile's refrigerating system, in the environment outside the battery box is gived off to the temperature of battery inside through the mode of liquid cooling, the radiating efficiency is high. On the other hand, the micro heat pipe array is a flat heat conductor with a porous structure formed by extruding a metal material, a plurality of micro heat pipes which are arranged side by side and are not communicated with each other are arranged inside the micro heat pipe array, the hydraulic diameter of each micro heat pipe is only 1.0nm, even smaller, the pressure bearing capacity of the pipe wall is extremely high, so that the leakage problem can be almost ignored, and the phase change working medium is a trace and non-conductive medium, so that the battery cannot be damaged even if the phase change working medium is damaged and leaked under extreme conditions; and the heat conduction partition plate is simultaneously used as a protective shell of the battery cell, the substrate of the liquid cooling plate tube heat exchanger is separated from the battery pack, and the substrate of the liquid cooling plate tube heat exchanger is sealed by sealing measures such as sealing rings or welding, so that the complete physical isolation between the substrate and the battery cell in the outer shell is realized, the cooling medium in the liquid cooling plate tube heat exchanger is effectively prevented from leaking into the battery pack, and the protection grade of the battery pack is ensured to reach the waterproof and dustproof grade of IP 67.

When the temperature of the battery pack in the dry-wet separation system is higher than a first set value, such as 35-42 ℃, the control system automatically starts a refrigeration system of an automobile to refrigerate and exchange heat with a liquid cooling plate pipe heat exchanger, and the heat on the surface of the battery pack is conducted to the liquid cooling plate pipe heat exchanger which is arranged outside the battery pack shell and connected with the refrigeration system through the micro heat pipe array to be exchanged.

In conclusion, the micro heat pipe array with efficient heat transfer is effectively combined with the liquid cooling mode, and one or two liquid cooling plate pipe heat exchangers are arranged outside each battery pack through the position and arrangement relationship of the micro heat pipe array and the battery units, so that the temperature inside the battery can be effectively conducted out, the overhigh temperature is prevented, the uniform temperature of the battery is ensured, and the heat dissipation efficiency is high.

The extending part is bent and attached to the heat-conducting partition plate, so that the contact area between the condensation section of the micro heat pipe array and the heat-conducting partition plate is larger, and the heat-conducting efficiency is improved.

The heat conducting gasket has the functions of heat conduction, electric insulation and ensuring good contact between the micro heat pipe array and the battery.

Drawings

Fig. 1 is an exploded view of a lithium battery pack thermal management system according to an embodiment 1 of the present invention;

FIG. 2 is a schematic view of FIG. 1 assembled;

FIG. 3 is a schematic partial cross-sectional view of one end of a battery cell of example 1;

fig. 4 is a schematic cross-sectional view of a battery cell of example 2.

1-a battery pack housing; 2-liquid cold plate pipe heat exchanger; 3-a refrigerant inlet; 4-refrigerant outlet; 5-a battery cell; 6-micro heat pipe array, 61-extension part, 7-heat conduction gasket and 8-electric heating film.

Detailed Description

For a clearer understanding of the contents of the present invention, reference will now be made in detail to the accompanying drawings 1 to 3 and specific examples.