An evaporator for battery thermal management and a battery thermal management device

Abstract

A battery thermal management device includes a pipeline, a condenser and an evaporator; the evaporator includes an upper shell plate, a liquid wick and a lower shell plate; the upper shell plate covers the lower shell plate to form a storage space; a liquid inlet is provided on one side of the storage space, and an air outlet is provided on the other side; the liquid wick has a porous structure and is located in the storage space, dividing the storage space into a compensation chamber connected to the liquid inlet and a steam chamber connected to the air outlet. Compared with the prior art, the battery thermal management device and evaporator of the present invention can improve the heat dissipation efficiency, and the stability and reliability of the overall circulation loop of the battery thermal management device are high.

Description

Technical Field

[0001] The present invention relates to the field of battery thermal management, and in particular to a battery thermal management evaporator, a battery thermal management device and a processing method for the battery thermal management evaporator. Background Art

[0002] Energy storage batteries are devices that use electrochemical reactions to store electrical energy and release it when needed. Existing batteries include lithium-ion batteries, lead-acid batteries, sodium-sulfur batteries, and zinc-air flow batteries. With the development of new energy technologies, especially new energy vehicles, battery requirements are increasingly moving towards super-fast charging, high safety, and high cycle life. However, during the charging and discharging process, existing batteries accumulate a large amount of heat due to their own resistance, and even produce a large temperature difference of 30°C inside the battery cell. The thermal conductivity of the energy storage battery material itself is too low to transfer the heat generated by the chemical reaction process in time. As a result, if the heat in the high-temperature area of ​​the pole ear cannot be diffused out in time, it will greatly affect the battery's charging and discharging performance and battery life, and even cause thermal runaway risks such as fire and explosion. Therefore, the key to the existing thermal management solution for energy storage batteries lies in high thermal conductivity and heat transfer speed.

[0003] The current heat dissipation solution for energy storage batteries is to use a liquid cooling plate for direct liquid cooling, so that low-temperature coolant flows through the bottom of the battery to remove the heat of the battery, thereby reducing the battery temperature. However, this heat dissipation technology only involves single-phase heat exchange, and the amount of heat absorbed is limited, which cannot meet the heat dissipation requirements when the battery is charged and discharged at a high rate. Summary of the invention

[0004] Based on this, the purpose of the present invention is to provide an evaporator for battery thermal management to improve the heat dissipation efficiency and meet the heat dissipation requirements of the battery during high-rate charging and discharging.

[0005] The technical solution adopted by the present invention is as follows:

[0006] An evaporator for battery management comprises an upper shell plate, a liquid wick and a lower shell plate; the upper shell plate covers the lower shell plate to form a accommodating space; a liquid inlet is provided on one side of the accommodating space, and an air outlet is provided on the other side; the liquid wick has a porous structure and is located in the accommodating space, dividing the accommodating space into a compensation chamber connected to the liquid inlet and a steam chamber connected to the air outlet.

[0007] Compared with the prior art, the evaporator of the present invention utilizes the phase change of the working fluid to absorb the heat of the battery, thereby improving the heat dissipation efficiency. At the same time, the evaporator has a gas-liquid separation structure to avoid the mutual influence between different working fluids, thereby improving the stability and reliability of the overall circulation loop of the battery thermal management device.

[0008] In another embodiment, the liquid inlet and the gas outlet are located on opposite sides of the accommodating space; along the projection perpendicular to the surface of the upper shell plate, the extension directions of the compensation cavity and the steam cavity are parallel to each other, and are alternately arranged in a direction perpendicular to their extension directions. The parallel and alternately arranged compensation cavity and steam cavity are conducive to improving the heat dissipation efficiency.

[0009] In another embodiment, the upper shell plate and / or the upper shell plate is provided with a support column protruding toward the accommodating space, and the support column is inserted into the liquid absorbent core and connected between the upper shell plate and the upper shell plate to facilitate the positioning of the liquid absorbent core in the accommodating space and increase the welding position between the upper shell plate and the upper shell plate to ensure that the evaporator is not easily deformed.

[0010] In another embodiment, the liquid absorbent core is provided with a liquid absorbent part, a connecting part, an inlet and an outlet; the inlet is connected with the liquid inlet, and the outlet is connected with the air outlet; the number of the liquid absorbent parts is more than three, and their extension directions are parallel to each other and separated by a distance; the connecting part is connected between two adjacent liquid absorbent parts; the compensation cavity includes two adjacent liquid absorbent parts, the connecting part and the inlet; the steam cavity includes two adjacent liquid absorbent parts, the connecting part and the outlet, so as to form a compensation cavity and a steam cavity parallel to each other.

[0011] In another embodiment, the upper shell plate and / or the upper shell plate is provided with a liquid diverter plate protruding in the direction of the accommodating space; the liquid diverter plate is located in the compensation cavity; projected along a direction perpendicular to the upper shell plate, the liquid diverter plate in the same compensation cavity is located between the two liquid suction parts, and the extension direction of the plate surface is parallel to the extension direction of the liquid suction part, so as to press the liquid working medium toward the liquid suction part.

[0012] In another embodiment, the upper shell plate and / or the upper shell plate is provided with a gas converging plate protruding in the direction of the accommodating space; the gas converging plate is located in the steam chamber; projected along a direction perpendicular to the upper shell plate, the number of gas converging plates in the same steam chamber is more than two, and they are respectively arranged on two liquid absorption parts opposite to each other, and the extension direction of the plate surface is parallel to the extension direction of the liquid absorption part, so as to gather the steam to the middle of the steam chamber.

[0013] In another embodiment, a first buffer chamber and a second buffer chamber are further provided in the accommodating space; the first buffer chamber is located between the inlet and the liquid inlet; the second buffer chamber is located between the outlet and the gas outlet to reduce the impact of the working fluid on the evaporator.

[0014] In another embodiment, the volume of the steam chamber is greater than the volume of the compensation chamber to prevent excessive pressure inside the evaporator.

[0015] In another embodiment, the pores on one side of the wick close to the compensation chamber are smaller than the pores close to the steam chamber, so as to reduce the permeability of the liquid medium and reduce the resistance of steam entering the steam chamber.

[0016] In addition, the present invention also provides a battery thermal management device, including a pipeline, a condenser and the above-mentioned evaporator; the pipeline is respectively connected between the outlet of the condenser and the liquid inlet, and the air outlet and the inlet of the condenser to form a circulation loop.

[0017] Compared with the prior art, the evaporator of the battery thermal management device of the present invention can absorb the heat of the battery by using the phase change of the working fluid, thereby improving the heat dissipation efficiency. At the same time, the evaporator has a gas-liquid separation structure to avoid the mutual influence between different working fluids, thereby improving the stability and reliability of the overall circulation loop of the battery thermal management device.

[0018] For better understanding and implementation, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of the battery thermal management device in the present invention;

[0020] Figure 2 It is a structural exploded view of the evaporator used for battery thermal management in the present invention;

[0021] Figure 3 A top view of the evaporator for battery thermal management after the upper housing is removed in the present invention;

[0022] Figure 4 The figure is a schematic diagram of the process of making an evaporator for battery thermal management in the present invention. DETAILED DESCRIPTION

[0023] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0024] Many techniques and steps are disclosed in describing the present invention, and it should be understood that each of these techniques and steps has its own benefits, and each can also be used in combination with one or more, or in some cases, all other disclosed techniques. Therefore, for the sake of clarity, unnecessary repetition of various possible combinations of various steps will be avoided herein. Of course, it should be clear that these combinations are fully within the scope of the present invention and claims.

[0025] In the following description, for the convenience of explanation, many specific details are set forth to provide a thorough understanding of the present invention. However, it is apparent that those skilled in the art can also practice the present invention without providing these specific details.

[0026] See also Figure 1 The energy storage battery thermal management device of the present invention includes a pipeline 10, a condenser 20 and an evaporator 30. The energy storage battery (not shown) is connected to the evaporator 30. When the energy storage battery is charged and discharged at a high rate, a large amount of heat is generated. The heat is transferred to the evaporator 30 through heat conduction, and the temperature of the evaporator 30 rises due to the heat. The pipeline 10 is connected between the inlet and outlet of the condenser 20 and the evaporator 30 to form a loop, and the working fluid flows between the condenser 20 and the evaporator 30 through the pipeline 10. The working fluid is any one of deionized water, ethanol, acetone and R410a, which can be converted from liquid to gas after heating, and can be restored from gas to liquid after cooling. After the liquid working medium flowing out of the condenser 20 flows into the evaporator 30, it absorbs the heat energy on the evaporator 30 and changes into a gaseous working medium. The internal pressure of the evaporator 30 increases, and the gaseous working medium flows back into the condenser 20 under the action of pressure. The condenser 20 cools it and turns it back into a liquid working medium to achieve circulation. The heat energy in the evaporator 30 is provided by the energy storage battery. The condenser 20 includes fins (not marked), and the cooling method can adopt cooling means in the prior art such as spray cooling and / or forced air cooling.

[0027] See also Figure 2 and Figure 3The evaporator 30 for thermal management of the energy storage battery includes an upper shell plate 31, a liquid wick 32 and a lower shell plate 33. In this embodiment, an outer side wall 331 surrounding its outer edge is protruding on one side of the plate surface of the lower shell plate 33 to form a semi-enclosed structure. The upper shell plate 31 covers the side of the lower shell plate 33 on which the outer side wall 331 is provided, so that a housing space (not marked) separated from the outside can be formed between the lower shell plate 33 and the upper shell plate 31. The liquid wick 32 is placed in the housing space to separate the housing space into a compensation chamber 34 and a steam chamber 35. The housing space is provided with a liquid inlet 38 communicating with the compensation chamber 34 on one side, and an air outlet 39 communicating with the steam chamber 35 on the other side opposite thereto. The outlet of the condenser 20 is connected to the liquid inlet 38 through the pipe 10, and the air outlet 39 is connected to the inlet of the condenser 20 through the pipe 10. Assuming that the straight line direction from the liquid inlet 38 to the gas outlet 39 is direction A, projected along the direction perpendicular to the plate surface of the upper shell plate 31, the extension direction of the compensation chamber 34 and the steam chamber 35 is parallel to the direction A, and they are alternately arranged side by side in a direction perpendicular to the direction A. Preferably, the volume of the steam chamber 35 is larger than the volume of the compensation chamber 34. In one embodiment, the volume ratio between the steam chamber 35 and the compensation chamber 34 is 8:2 to prevent the internal pressure of the evaporator 30 from being too high. Further, in order to prevent the working fluid flow rate from being too high and impacting the evaporator 30, a first buffer chamber 36 and a second buffer chamber 37 are also provided in the accommodating space. The first buffer chamber 36 is located between the compensation chamber 34 and the liquid inlet 38, and the second buffer chamber 37 is located between the steam chamber 35 and the gas outlet 39. When the working medium enters the evaporator 30, it is first buffered in the first buffer chamber 36 and then flows into the compensation chamber 34; when the working medium leaves the evaporator 30, it is first buffered in the second buffer chamber 37 and then flows out of the evaporator 30. Further, along the projection perpendicular to the plate surface of the upper shell plate 31, the extension direction of the first buffer chamber 36 and the second buffer chamber 37 is perpendicular to the A direction, that is, perpendicular to the extension direction of the compensation chamber 34 and the steam chamber 35. The energy storage battery is placed on the outer plate surface of the upper shell plate 31 and / or the lower shell plate 33 for heat transfer. In order to transfer heat more evenly, the upper shell plate 31 or the lower shell plate 33 is preferably made of copper.

[0028] In this embodiment, the lower shell plate 33 is a rectangular structure, and the outer side wall 331 includes a first outer side wall 331A, a second outer side wall 331B, a third outer side wall 331C and a fourth outer side wall 331D connected in sequence. The first outer side wall 331A is opposite to the third outer side wall 331C, and the second outer side wall 331B is opposite to the fourth outer side wall 331D. The liquid inlet 38 is provided on the second outer side wall 331B, and the gas outlet 39 is provided on the fourth outer side wall 331D. Further, according to the speed of steam generation, the number of the liquid inlet 38 can be set to be different from the number of the gas outlet 39, for example, the number of the liquid inlet 38 is one, and the number of the gas outlet 39 is three, so as to further prevent the internal pressure of the evaporator 30 from being too high. The lower shell plate 33 is a flat plate, and the first outer side wall 331A, the second outer side wall 331B, the third outer side wall 331C and the fourth outer side wall 331D are respectively connected to the top of the lower shell plate 33.

[0029] The absorbent core 32 has a porous structure, and extends back and forth between the liquid inlet 38 and the air outlet 39 to form a compensation chamber 34 and a steam chamber 35 that are parallel to each other and connected through the porous structure. The porous structure can provide capillary driving force. In this embodiment, the absorbent core 32 is provided with a bottom plate 321, a liquid absorbing portion 322, a connecting portion 323, an inlet 324 and an outlet 325. The bottom plate 321 is located on the inner plate surface of the lower shell plate 33, and more than three liquid absorbing portions 322 are arranged on the plate surface of the bottom plate 321 facing away from the lower shell plate 33 and extending along the A direction. The multiple liquid absorbing portions 322 are arranged in parallel in a direction perpendicular to the A direction, and there is a certain gap between two adjacent liquid absorbing portions 322. On the side close to the liquid inlet 38, the connecting portion 323 and the inlet 324 are alternately connected between two adjacent liquid suction portions 322; on the side close to the gas outlet 39, the connecting portion 323 and the outlet 325 are alternately connected between two adjacent liquid suction portions 322, the inlet 324 is connected to the liquid inlet 38, and the outlet 325 is connected to the gas outlet 39. Two adjacent liquid suction portions 322 and the connecting portions 323 and the outlet 325 located at both ends of the two liquid suction portions 322 and opposite to each other form the compensation chamber 34, or two adjacent liquid suction portions 322 and the connecting portions 323 and the inlet 324 located at both ends of the two liquid suction portions 322 and opposite to each other form the steam chamber 35. In the direction perpendicular to the A direction, the compensation chamber 34 and the steam chamber 35 are alternately arranged. Further, the first buffer chamber 36 is located between the inlet 324 and the liquid inlet 38, and the second buffer chamber 37 is located between the outlet 325 and the gas outlet 39. The working fluid entering the first buffer chamber 36 from the liquid inlet 38 first enters the compensation chamber 34, is sucked into the liquid absorption portion 322 by the porous structure, and is heated to form steam. The steam enters the steam chamber 35, and then flows toward the second buffer chamber 37 under the action of pressure, and then flows out of the evaporator 30 from the gas outlet 39.

[0030] Further, a plurality of guide plates 331, support columns 332, liquid diverter plates 333 and gas convergence plates 334 are protrudingly provided on the plate surface of one side of the lower shell plate 33 close to the liquid absorbent core 32. Accordingly, a through hole (not marked) is provided on the bottom plate 321 for inserting the guide plates 331, support columns 332, liquid diverter plates 333 and gas convergence plates 334 to limit the position of the liquid absorbent core 32. Further, the guide plates 331, support columns 332, liquid diverter plates 333 and gas convergence plates 334 are at the same height on the plate surface of the lower shell plate 33. A plurality of support columns 332 are protrudingly provided at even intervals in the compensation chamber 34, the steam chamber 35, the first buffer chamber 36 and the second buffer chamber 37, and abut against the upper shell plate 31 for support. The liquid diverter plate 333 is located in the compensation chamber 34. Projected along the direction perpendicular to the plate surface of the upper shell plate 31, in the same compensation chamber 34, the plate surface of the liquid diverter plate 333 faces the two liquid suction parts 322 respectively, and the plate surface extends along the A direction, and there is a certain gap between the two liquid suction parts 322, and the liquid working medium entering the compensation chamber 34 is diverted by the liquid diverter plate 333 and pressed into the liquid suction parts 321 on both sides. Further, in the same compensation chamber 34, the number of the liquid diverter plates 333 is more than two, and they are arranged at equal intervals along the A direction to evenly distribute the liquid working medium in the compensation chamber 34. The gas converging plate 334 is located in the steam chamber 35. In the same steam chamber 35, the number of the gas convergence plates 334 is more than two, and each gas convergence plate 334 is respectively opposite to the two liquid suction parts 322, and the extension direction of the plate surface is parallel to the A direction. The gaseous working medium coming out of the liquid suction part 322 is converged to the middle of the steam chamber 35 by the gas convergence plates 334, so as to reduce the reflux of steam to the liquid suction part 322. Preferably, in the same steam chamber 35, the number of the gas convergence plates 334 on the liquid suction part 322 on the same side is more than two, and they are arranged at equal intervals along the A direction, and the liquid suction part 322 on the other side is also provided with a gas convergence plate 334 opposite thereto to guide the steam. The guide plates 331 are respectively arranged in the first buffer chamber 36 and the second buffer chamber 37. In the first buffer chamber 36, a guide plate 331 is provided near each inlet 324, one end of the guide plate 331 is close to the inlet 324, and the other end extends toward the liquid inlet 38. When projected along a direction perpendicular to the surface of the upper shell plate 31, the extension direction of the guide plate 331 is not parallel to the A direction, and the liquid working medium entering from the liquid inlet 38 flows along the surface of the guide plate 331 toward each inlet 323.In the second buffer chamber 37 , when projected in a direction perpendicular to the surface of the upper shell plate 31 , a guide plate 331 is provided near each outlet 325 , and one end of the guide plate 331 is close to the outlet 324 , and the other end extends toward the air outlet 39 , so as to guide the steam in the steam chamber 35 from the outlet 325 to the air outlet 35 .

[0031] In addition, in this embodiment, the guide plate 331, the support column 332, the liquid diverter plate 333 and the gas convergence plate 334 are arranged on the lower shell plate 33, but according to needs, the guide plate 331, the support column 332, the liquid diverter plate 333 and the gas convergence plate 334 can also be set on the lower shell plate 33, or at least one of the guide plate 331, the support column 332, the liquid diverter plate 333 and the gas convergence plate 334 can be set on the lower shell plate 33, and the rest can be set on the upper shell plate 31.

[0032] See also Figure 4 Based on the structure of the above-mentioned evaporator 30, the manufacturing steps thereof are now described. In this embodiment, the width of the upper shell plate 31 and the lower shell plate 33 is 100 mm to 300 mm, the length is 100 mm to 500 mm, and the thickness is 3 mm to 30 mm.

[0033] Step S100: setting the upper shell plate 31 and the lower shell plate 33 according to the size of the energy storage battery.

[0034] The guide plate 331, the support column 332, the liquid diverter plate 333 and the gas converging plate 334 are cut out from the upper shell plate 31 and / or the lower shell plate 33 according to machining accuracy and surface smoothness through machining processes such as CNC machine tool milling and drilling to ensure the performance and stable operation of the evaporator 30.

[0035] Step S110 : arranging the liquid absorbent core 32 according to the shapes of the upper shell plate 31 and the lower shell plate 33 and fixing it to the upper shell plate 31 and / or the lower shell plate 33 .

[0036] The method comprises placing an upper shell plate 31 and / or a lower shell plate 33 provided with the guide plate 331, the support column 332, the liquid diverter plate 333 and the gas converging plate 334 in the graphite mold; filling the graphite mold with metal powder, including but not limited to at least one metal powder of copper, nickel, aluminum and stainless steel; and performing high-temperature sintering molding on the graphite mold with the upper shell plate 31 and / or the lower shell plate 33 in an atmosphere furnace containing a mixture of N2 and H2 to obtain a liquid absorbent core 32 with a porous structure.

[0037] Among them, the structure of the porous structure of the liquid absorbent core 32 can adopt a single mesh structure formed by metal powder of the same particle size, so that the pore size of the liquid absorbent core 32 is uniform; or a multi-mesh structure formed by metal powders of different particle sizes in a certain proportion can be adopted, so that the liquid absorbent core 32 obtains different porosities by adjusting the ratio of metal powders of different pore sizes; further, by adjusting the ratio of metal powders at different positions in the graphite mold, the pore sizes at different positions of the liquid absorbent core 32 are different, for example, the part close to the compensation cavity 34 can adopt small-particle metal powder to reduce permeability, and the part close to the steam cavity 35 can adopt large-particle metal powder to increase porosity, thereby reducing gas resistance, that is, in the liquid absorbent core 32, the pores on the side close to the compensation cavity 34 are smaller than the pores close to the steam cavity 35.

[0038] In this embodiment, the lower shell plate 33 is set in the graphite mold, and after the metal powder is filled in the accommodation space surrounded by the outer side wall 331 of the lower shell plate 33, the cover plate of the graphite mold is covered and sintered, and the particle size of the metal powder is between 50 and 1000 meshes. Powder high-temperature sintering has the advantage of adjustable porosity, and can obtain a sintered powder-type liquid-absorbing core with higher capillary pressure and excellent anti-gravity ability, and realize a highly controllable pore structure.

[0039] Step S120: welding the upper shell plate 31 and the lower shell plate 33 together.

[0040] In this embodiment, during welding, low-temperature solder paste is applied on the side of the guide plate 331, the support column 332, the liquid diverter plate 333 and the gas converging plate 334 toward the upper shell plate 31, and then the upper shell plate 31 is pressurized and heated to ensure that the upper shell plate 31 and the lower shell plate 33 fit tightly, further ensuring the independence between the compensation chamber 34 and the steam chamber 35.

[0041] Compared with the prior art, the evaporator and battery management device of the present invention use internal capillary force and steam pressure as driving force, do not require additional mechanical equipment, can achieve long-term high-reliability operation, and thus provide an efficient heat dissipation solution, specifically having the following advantages:

[0042] (1) The evaporator with a gas-liquid separation structure can prevent the gaseous working fluid from being blocked by the liquid working fluid during operation. At the same time, the working fluid flows in one direction under the impetus of vapor pressure to drive the circulation. In other words, the gas-liquid separation structure of the evaporator can improve the stability and reliability of the overall circulation loop.

[0043] (2) The evaporator forms alternating parallel channels in the length direction, which are separated by a porous wick. The liquid working medium completely soaks the evaporation surface under the capillary suction force of the porous wick, absorbs the heat from the heat source and changes into a gaseous working medium to enter the evaporation chamber. The channels are independent of each other and form a gas-liquid separation structure, which improves the maximum heat dissipation power of the evaporator and ensures the stability of the cycle.

[0044] (3) The liquid absorbent core is formed by high-temperature sintering of metal powder to form a sintered neck connection. Different metal powder pore sizes can achieve adjustable porosity, higher capillary pressure and better anti-gravity ability. At the same time, the metal powder liquid absorbent core can more effectively prevent other working fluids in the evaporation chamber from entering the compensation chamber, thereby improving the overall circulation loop's ability to cope with different heat dissipation powers and heat transfer performance.

[0045] (4) The guide plates, support columns, liquid diverter plates and gas convergence plates in the accommodation space can play a supporting and guiding role. At the same time, the welding points between the lower shell plate and the upper shell plate are increased to ensure that the upper shell plate and the lower shell plate fit closely and further ensure the independence of the compensation chamber and the evaporation chamber.

[0046] (5) The evaporator structure can effectively solve the problems of traditional battery heat pipe devices that cannot meet the needs of high-power devices, fail to start under low power, and cannot meet the needs of multiple heat sources for heat dissipation.

[0047] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. An evaporator for battery management, characterized in that: The device comprises an upper shell plate, a liquid wick and a lower shell plate; the upper shell plate covers the lower shell plate to form a receiving space; a liquid inlet and an air outlet are respectively arranged on opposite sides of the receiving space; the liquid wick has a porous structure and is located in the receiving space, dividing the receiving space into a compensation chamber connected to the liquid inlet and a steam chamber connected to the air outlet; Projected in a direction perpendicular to the surface of the upper shell plate, the extension directions of the compensation chamber and the steam chamber are parallel to each other and point from the liquid inlet to the gas outlet, and are alternately arranged in a direction perpendicular to their extension directions; The upper shell plate and / or the upper shell plate are provided with a liquid diverter plate and a gas converging plate protruding toward the accommodating space; the liquid diverter plate is located in the compensation chamber, and the extension direction of the plate surface is parallel to the extension direction of the compensation chamber, so that the plate surfaces on both sides of the liquid diverter plate face the steam chamber respectively and have a gap with the two side walls of the compensation chamber; the gas converging plate is located in the steam chamber, and the number of gas converging plates in the same steam chamber is more than two, and the extension direction of the plate surface is parallel to the extension direction of the steam chamber, so that the plate surfaces on both sides of the gas converging plate face the compensation chamber respectively and are connected with the two side walls of the steam chamber respectively.

2. The evaporator according to claim 1, characterized in that: The upper shell plate and / or the upper shell plate are provided with a support column protruding toward the accommodating space, and the support column is inserted into the liquid absorbent core and connected between the upper shell plate and the upper shell plate.

3. The evaporator according to claim 1, characterized in that: The liquid absorbent core is provided with a liquid absorbent part, a connecting part, an inlet and an outlet; the inlet is connected with the liquid inlet, and the outlet is connected with the air outlet; the number of the liquid absorbent parts is more than three, and their extension directions are parallel to each other and separated by a distance; the connecting part is connected between two adjacent liquid absorbent parts; the compensation chamber includes two adjacent liquid absorbent parts, the connecting part and the inlet; the steam chamber includes two adjacent liquid absorbent parts, the connecting part and the outlet.

4. The evaporator according to claim 3, characterized in that: Projected along a direction perpendicular to the upper shell plate, the liquid diverter plate in the same compensation cavity is located between the two liquid suction parts.

5. The evaporator according to claim 3, characterized in that: Projected along a direction perpendicular to the upper shell plate, the gas converging plates are respectively arranged on the two liquid absorbing parts in a relatively opposite manner.

6. The evaporator according to claim 3, characterized in that: A first buffer cavity and a second buffer cavity are further provided in the accommodating space; the first buffer cavity is located between the inlet and the liquid inlet; and the second buffer cavity is located between the outlet and the air outlet.

7. The evaporator according to claim 1, characterized in that: The volume of the steam chamber is greater than the volume of the compensation chamber.

8. The evaporator according to claim 1, characterized in that: The pores on one side of the liquid absorbent core close to the compensation cavity are smaller than the pores close to the steam cavity.

9. A battery management device, characterized in that: It comprises a pipeline, a condenser and the evaporator according to any one of claims 1 to 8; the pipeline is respectively connected between the outlet of the condenser and the liquid inlet, and the gas outlet and the inlet of the condenser to form a circulation loop.

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