WO2017202147A1

WO2017202147A1 - Multiphase-change heat balance system for use in lithium battery pack of electric vehicle

Info

Publication number: WO2017202147A1
Application number: PCT/CN2017/079577
Authority: WO
Inventors: 钱小飞
Original assignee: 钱小飞
Priority date: 2016-05-26
Filing date: 2017-04-06
Publication date: 2017-11-30
Also published as: CN109328415A; CN205752445U

Abstract

The invention discloses a multiphase-change heat balance system for use in a lithium battery pack of an electric vehicle. The system comprises a gas-liquid phase-change thermally conductive channel comprising a gas-liquid phase-change thermally conductive material. The gas-liquid phase-change thermally conductive channel comprises at least one extension channel and at least one cylinder accommodating a lithium battery cell. The cylinder comprises a hollow wall communicating with the extension channel. An outer wall of the lithium cell is suitable for tightly matching an inner wall of the cylinder, or having a thermally conductive glue filled in between the outer wall of the lithium cell and the inner wall of the cylinder to provide thermal conduction. A liquid-solid phase-change energy-storage material is filled at a circumferential outer side of all the cylinders, respectively. The liquid-solid phase-change energy-storage material comprises three or more sets of liquid-solid phase-change energy-storage materials. Each set of the liquid-solid phase-change energy-storage materials operates at a different temperature interval. When the temperature of the lithium battery cell increases, the liquid-solid phase-change energy-storage materials can absorb and store thermal energy to reduce a rate of temperature increase; whereas when the temperature of the lithium battery cell decreases, the liquid-solid phase-change energy-storage materials can release the previously stored thermal energy to reduce a rate of temperature decrease. Therefore, the embodiment can keep, for a longer period of time, the temperature of the lithium battery cell in a preconfigured operating temperature range.

Description

Multi-phase phase change heat balance system for electric vehicle lithium battery pack

[0001] The present invention relates to a multi-phase phase change heat balance system for an electric vehicle lithium battery package, which is used for all-weather heat management of an electric vehicle lithium battery core.

Background technique

[0002] An electric vehicle uses a lithium battery pack as a power source to drive the vehicle. The battery of the lithium battery is suitable for charging and discharging in a temperature range of 20-4 o °c, in order to exert the maximum performance of the lithium battery. However, the lithium battery is charging

Heat is generated during the discharge process, so that the temperature of the lithium battery exceeds the above-mentioned suitable temperature range, thereby affecting the performance and safety of the lithium battery, for example, the battery cannot be fully charged during charging or the amount of electricity discharged during the discharge is much smaller than the set value. , affecting the cruising range of electric vehicles. In the prior art, some heat conducting devices are used to derive the heat of the lithium battery core (such as air cooling, water cooling), such as a single thermal management system using a solid-solid or solid-liquid composite phase change material composed of a plurality of phase change materials. . However, the solid-solid or solid-liquid phase change material itself has low thermal conductivity and its heat storage performance is very good, so these materials are not suitable for use as a heat conducting device, which is not conducive to the rapid derivation of lithium battery core heat.

[0003] On the other hand, when the temperature of the lithium battery cell is lower than the above-mentioned suitable temperature range, the charging and discharging performance thereof will be significantly decreased, especially when the operating environment of the electric vehicle is a cold region lower than o °c, the charging of the electric vehicle The discharge performance will drop by more than 35%, which will adversely affect the cruising range of electric vehicles. In addition, when an electric vehicle is charged in a low temperature environment, the lithium battery has a risk of explosion. Therefore, after the ambient temperature is lower than the above-mentioned suitable temperature range, the lithium battery of the electric vehicle is insulated and heated to maintain the lithium battery core within a suitable temperature range, which will facilitate the lithium battery to exert maximum charging and discharging performance and prevent electric vehicles. The cruising range is reduced and its safety is guaranteed.

technical problem

[0004] The technical problem to be solved by the present invention is to provide a multi-phase phase change heat balance system for an electric vehicle lithium battery package, which can exchange heat with the lithium battery core more quickly.

Problem solution

Technical solution [0005] In order to solve the primary technical problem, the present invention provides a multi-phase phase change heat balance system, comprising: a gas-liquid phase change heat conduction channel containing a gas-liquid phase change material, and the gas-liquid phase change heat conduction channel includes at least one extension channel And a cylinder for accommodating the lithium battery, the hollow wall of all the cylinders is in communication with the extension channel, and the outer wall of the lithium battery is adapted to closely fit the inner wall of the cylinder or to be filled with a thermal adhesive for heat transfer.

[0006] The circumferential outer side of each cylinder is respectively filled with a solid-liquid phase change energy storage body (specifically: a container filled with a solid-liquid phase change composite material, and the wall body is suitable for rapid heat conduction (preferably a metal container)), the solid The liquid phase change energy storage body contains at least three groups, and each group of solid-liquid phase change energy storage bodies contains solid-liquid phase change materials with different working temperature ranges (ie, solid-liquid phase change composite materials), respectively: Solid-liquid phase change material at 10~20°C, solid-liquid phase change material with working temperature range of 20~30°C and solid-liquid phase change material with working temperature range of 35~45°C.

[0007] In the solid-liquid phase change mixture, the solid-liquid phase change material with an operating temperature range of 10 to 20 ° C accounts for 30%, and the solid-liquid phase change material with an operating temperature range of 20 to 30 ° C accounts for 40%, and the working temperature. Solid-liquid phase change materials with a range of 35~45 °C account for 30<3⁄4.

[0008] The extended end of the extension channel is provided with a vehicle-mounted cold heat exchanger, and the vehicle-mounted cold heat exchanger is a cold and heat output end of the vehicle air-conditioning system.

[0009] The vehicle-mounted cold heat exchanger includes a plurality of heat transfer fins and heat transfer tubes, the heat transfer sheets are parallel to each other, and the extending passages pass through the heat transfer sheets and are heat-transferred to the heat transfer sheets, and the heat transfer tubes pass through the respective heat transfer tubes. The heat sheet is heat-transferred and connected to each heat transfer sheet, and the heat transfer tube is connected to the heat transfer connection of the vehicle air conditioning system (specifically: the heat transfer tube and the condensation tube of the vehicle air conditioning system, the heat exchange water tank and/or the heating wire, etc. Parts are connected).

[0010] The multi-phase phase change heat balance system further includes a heat balance processing unit, and the heat balance processing unit includes: a controller connected to the ECU of the electric vehicle, and a plurality of temperature sensors connected to the controller; the controller is adapted to pass the temperature sensor Or the thermal sensor collects the ambient temperature, the temperature of the gas-liquid phase change material, and the temperature of the solid-liquid phase change energy storage body, and the controller is electrically connected to the vehicle air conditioning system and the vehicle power system of the electric vehicle through the ECU control. Vehicle power systems include: on-board gasoline or diesel engines, or hydrogen fuel cells and other power sources

[0011] The present invention also provides a method for operating a multi-phase phase change heat balance system, comprising:

[0012] When the temperature of the lithium battery core rises, the lithium battery core derives heat into the solid-liquid phase change energy storage body through the gas-liquid phase change heat conduction channel, and the solid-liquid phase change energy storage body absorbs heat in the working temperature range of each phase change material. When solid liquid is detected After the temperature of the phase change energy storage device reaches the set upper limit value, the cooling mode of the vehicle air conditioning system is started, and the vehicle air conditioning system exchanges heat with the lithium battery through the vehicle cold heat exchanger and the gas-liquid phase heat conduction channel;

[0013] When the temperature of the lithium battery core drops to the lower limit value 吋, the solid-liquid phase change energy storage body emits heat and transmits the heat to the lithium battery through the gas-liquid phase change heat conduction channel, and when the temperature of the solid-liquid phase change energy storage body is detected again After the set lower limit value is reached, the heating mode of the vehicle air conditioning system is started, and the vehicle air conditioning system exchanges heat with the lithium battery through the vehicle cold heat exchanger and the gas-liquid phase heat conduction channel.

[0014] When the ambient temperature is lower than 20 ° C, the upper limit of the temperature setting is 30 ° C, the lower limit is 10 ° C; when the ambient temperature is located at 20-30 ° C, the upper limit of the temperature setting is 35 °C, no setting lower limit; When the ambient temperature is higher than 30 °C, if the lithium battery is in charge and discharge state, the upper limit of temperature setting is 40 °C, otherwise the upper limit of temperature setting is 45 ° C, no lower limit is set.

[0015] When the vehicle air conditioning system is started, if the lithium battery is in a discharged or deactivated state, the vehicle air conditioning system is powered by the vehicle's vehicle power system; if the lithium battery is in a charging state, the vehicle air conditioning system is powered by the charging pile.

[0016] The present invention also provides a solid-liquid phase change mixture for a multi-phase phase change heat balance system, comprising: 30% solid-liquid phase change material with an operating temperature range of 10-20 ° C, 40% The solid-liquid phase change material with working temperature range of 20~30 °C and 30% solid-liquid phase change material with working temperature range of 35~45 °C.

Advantageous effects of the invention

Beneficial effect

[0017] Compared with the prior art, the technical effects of the present invention are:

[0018] 1) The gas-liquid phase change heat conduction channel has a thermal conductivity much higher than that of the metal, and the gas-liquid phase change heat conduction channel is used to conduct heat, thereby improving heat transfer efficiency with the lithium battery core, and accommodating the column of the single lithium battery core. The heat transfer between the inside of the cylinder and the lithium battery can make the heat transfer contact area of the lithium battery core and the gas-liquid phase variable heat conduction channel larger, further improving the heat transfer efficiency of the lithium battery core; the column barrel is connected with the extension channel, and can be composed of a lithium battery core The lithium battery and the cold and heat sources other than the lithium battery are more convenient for heat exchange.

[0019] 2) The solid-liquid phase change energy storage body disposed on the outer side of the cylinder can absorb heat and store or release the stored heat as needed, and when the lithium battery is heated, the stored energy can be absorbed to delay the heating rate of the lithium battery. When the lithium battery is cooled, the stored heat can be released to delay the cooling rate of the lithium battery, so that the lithium battery is kept within the set operating temperature range for a longer period of time, and the operating temperature range is 10~. 20. C, 20~30. C and 35~45. C three solid-liquid phase change materials can keep the lithium battery core at the optimum temperature in the longer turn, which is beneficial to the lithium battery to maintain normal charging and discharging performance, and it is also beneficial to reduce external cooling or heating. The frequency of heat exchange between the equipment and the lithium battery plays a role in energy saving and emission reduction.

3) The content of solid-liquid phase change material with working temperature range of 20~30°C is higher than that of the other two solid-liquid phase change materials, so that the lithium battery core is kept at a temperature of 20~30°C for a longer period, which is beneficial to play out. Lithium battery's maximum charge and discharge

[0021] 4) The vehicle-mounted cold heat exchanger is an intermediate part of the heat exchange between the vehicle air-conditioning system and the lithium battery core. When the temperature of the lithium battery core exceeds the adjustment range of the solid-liquid phase change energy storage body, the refrigeration or heating of the vehicle air-conditioning system is utilized. The function is to exchange heat with the lithium battery through the on-board cold heat exchanger and the gas-liquid phase heat conduction channel, so that the temperature of the lithium battery core is kept within a controllable range.

[0022] 5) The heat balance processing unit analyzes and controls the working time, working state and vehicle air conditioning of the vehicle air conditioning system by collecting the ambient temperature, the temperature of the solid-liquid phase change energy storage body, and the charging, discharging or deactivating state of the lithium battery core. The power source of the system realizes the all-weather automation of the operation of the multi-phase phase change heat balance system.

[0023] 6) During the rise or fall of the temperature of the lithium battery, the gas-liquid phase change heat conduction channel or the solid-liquid phase change energy storage body is first used to control the temperature change, and finally the vehicle air conditioning system is used to control the temperature change thereof. The lithium battery core can be kept in the required temperature range for a longer period of time, which can save energy and reduce emissions. The vehicle air conditioning system can be used to forcibly cool or heat the lithium battery core, so that the lithium battery core can be kept under control. Within the temperature range.

[0024] 7) according to different environmental temperatures, the thermal conductivity of the gas-liquid phase change heat conduction channel and the phase change characteristics of the solid-liquid phase change energy storage body, setting different temperature setting upper and lower limit values, the lithium battery core can be maintained In a better operating temperature range, lithium batteries work more efficiently.

[0025] 8) Lithium battery charging state 吋, the vehicle air conditioning system is powered by the power supply pile, which can effectively save the energy of the vehicle power system, effectively reduce the load of the vehicle power system, and improve energy utilization efficiency.

[0026] 9) 30% solid-liquid phase change material with working temperature range of 10~20 °C, 40% solid-liquid phase change material with working temperature range of 20~30 °C and 30% working temperature range It is a solid-liquid phase change mixture of 35~45 °C solid-liquid phase change material, which can maintain a longer temperature in the range of 20~30 °C during the phase change process. Brief description of the drawing

DRAWINGS [0027] In order to clarify the innovative principle of the invention and its technical advantages over existing products, possible embodiments are explained below by means of a non-limiting example of the application of the principles by means of the figures. In the picture:

1 is a three-dimensional schematic diagram of a multi-phase phase change heat balance system of the present invention;

2 is a front elevational view of a multi-phase phase change heat balance system of the present invention; [0029] FIG.

3 is a cross-sectional view along line A-A of the multi-phase phase change heat balance system of the present invention.

Embodiments of the invention

[0031] As shown in FIG. 1-3, the multi-phase phase change heat balance system of the present invention comprises: a solid-liquid phase change energy storage body 1, a gas-liquid phase change heat conduction channel 2, an extension channel 21, a column 22, and a lithium battery. Core 3, on-vehicle cold heat exchanger 4, heat transfer fins 41, heat transfer tubes 42.

[0032] The gas-liquid phase change heat conduction channel 2 includes a pair of parallel extending passages 21 and a plurality of cylinders 22 vertically passing through the pair of extending passages 21, all of which are in communication with the extending passages 21, and each of the cylindrical tubes 22 is adapted to For accommodating a single lithium battery cell 3, the outer side wall of each lithium battery cell 3 is closely matched with the inner wall of the cylinder 22 (it may also be filled with a heat conductive medium such as a thermal conductive silica gel), and the circumferential outer side of each cylinder 22 is filled with a solid liquid phase. Change energy storage body 1. The portion of the extension passage 21 adjacent to the cylinder 22 is wider than the rest of the extension passage 21.

[0033] The extended end of the extension channel 21 is provided with a vehicle-mounted cold heat exchanger 4, and the vehicle-mounted cold heat exchanger 4 includes a heat transfer fin 41 and a heat transfer tube 42. The plurality of heat transfer fins 41 are arranged in parallel and equidistantly. The extension channel 21 passes through the plurality of heat transfer fins 41 and is fixedly coupled to each of the heat transfer fins 41, and the heat transfer tubes 42 located between the pair of extension passages 21 pass through the plurality of heat transfer fins 41 and A heat transfer connection is fixed to each of the heat transfer sheets 41.

[0034] The heat transfer tube 42 is thermally coupled to a vehicle air conditioning system (not shown), and the vehicle air conditioning system is electrically connected to and controlled by a thermal management system (BMS), and the BMS collects ambient temperature and temperature through the thermal sensor. The liquid phase change energy storage body 1 and the temperature of the gas-liquid phase change heat conduction channel 2, the BMS calculates and analyzes and controls the operation of the vehicle air conditioning system according to the above three temperatures, thereby adjusting the temperature of the lithium battery core 3. The BMS is electrically connected to the onboard power system of the electric vehicle to regulate the power source of the vehicle air conditioning system.

[0035] The solid-liquid phase change energy storage body 1 comprises at least three groups separated from each other, and each set of solid-liquid phase change energy storage body 1 is provided with a solid-liquid phase change mixture composed of three kinds of solid-liquid phase change materials. The operating temperature ranges of the three solid-liquid phase change materials are: 10~20°C in the low temperature zone (all solid phase below 10°C, full liquid phase above 20°C), and 20~30 in the medium temperature zone. °C (all solid phase below 20 °C, full liquid phase above 30 °C), material in high temperature zone is 3 5~45°C (all solid phase below 35°C, full liquid phase above 45°C), the three materials independently work in the corresponding temperature range without mutual interference. In general, the mass ratio of the three materials in the solid-liquid phase change mixture is: 30% in the low temperature zone, 40% in the medium temperature zone, and 30% in the high temperature zone. The mass ratio of the three materials is not limited to the above ratio, and can be selected according to the external ambient temperature range in which the lithium battery is long-term. Each solid-liquid phase change material has its own phase change temperature threshold, which has the effect of absorbing or releasing heat significantly within the threshold range. When the threshold value is exceeded, the heat is no longer absorbed or released.

[0036] The above three kinds of solid-liquid phase change materials may be phase change wax energy storage plates produced by Shanghai Joule Wax Co., Ltd., or may be produced by units such as China Aerospace Science and Industry Group and Aerospace Haiying (Zhenjiang) Special Materials Co., Ltd. Composite phase change material energy storage plate; or, using inorganic eutectic phase change energy storage plate produced by Changzhou Haika Solar Heat Pump Co., Ltd.; or, using organic composite phase change energy storage plate produced by Shanxi Institute of Coal Chemistry, Chinese Academy of Sciences ( Such as the high thermal conductivity paraffin and graphite phase change composite disclosed in the patent document CN103555282A. The solid-liquid phase change material can also be referred to Patent Documents CN103131395A, CN101982518A, CN10477674 3A, and the like.

[0037] The gas-liquid phase change heat-conducting channel 2 is provided with a gas-liquid phase change material, as shown in Table 1, the heat transfer efficiency of the gas-liquid phase change material is hundreds to thousands of high-heat-conducting metal silver. The gas-liquid phase change heat conduction channel 2 containing the gas-liquid phase change material can exchange heat with the lithium battery core 3 more quickly, ensuring that the lithium battery core 3 does not generate thermal imbalance, and can compensate for the low thermal conductivity of the solid-liquid phase change material. The insufficiency solves the structural complexity and uneconomical problems of conventional air-cooled and water-cooled systems.

[0038] The working process of the multi-phase phase change heat balance system of the present invention comprises the following steps:

[0039] (1) When the ambient temperature is lower than 20 ° C

[0040] 1) If the lithium battery cell 3 is in charge and discharge process, the heat generated by the lithium battery cell 3 is first transmitted to the gas-liquid phase change heat conduction channel 2 through the column 22 and is diverged from the gas-liquid phase change heat conduction channel 2, The heat of the helium is transferred from the gas-liquid phase to the heat-conducting channel 2 to the surrounding solid-liquid phase change energy storage body 1, and the solid-liquid phase change energy storage body 1 absorbs heat in the working temperature range of each phase change material until the solid-liquid phase changes energy storage. The temperature of the body 1 reaches 30 ° C, and the materials in the low temperature zone and the medium temperature zone are all converted into a liquid phase, and the ability of the entire solid-liquid phase change energy storage body 1 to continue to store heat is weakened, and the BMS detects the solid-liquid phase change energy storage body. The temperature of 1 reaches 30 °C, and the cooling mode of the vehicle air conditioning system is started. The vehicle air conditioning system exchanges heat with the gas-liquid phase heat conduction channel 2 through the vehicle cold heat exchanger 4, and accelerates the heat generated by the lithium battery core 3 from the gas phase. The variable heat conduction channel 2 is derived, thereby preventing the temperature of the lithium battery core 3 from continuing Continue to rise.

[0041] 2) If the lithium battery cell 3 is in the deactivated state, the temperature of the lithium battery cell 3 is gradually decreased from the working state, and the solid-liquid phase change energy storage body 1 is stored in the operating temperature range of each phase change material. The heat is transferred to the lithium battery cell 3 through the gas-liquid phase change heat conduction channel 2, thereby slowing down the temperature drop rate of the lithium battery cell 3, and the temperature of the solid-liquid phase change energy storage body 1 is lowered to 10 ° C, and all phase change materials are converted into In the solid phase, the energy storage board 1 no longer releases heat. When the BMS detects that the temperature of the solid-liquid phase change energy storage body 1 drops to 10 ° C, the heating mode of the vehicle air conditioning system is started, and the vehicle air conditioning system passes the vehicle hot and cold heat. The exchanger 4 exchanges heat with the gas-liquid phase change heat conduction channel 2, and transfers the heat generated by the vehicle air conditioning system to the lithium battery cell 3 through the gas-liquid phase change heat conduction channel 2, thereby preventing the temperature of the lithium battery core 3 from continuing to drop, so that the next lithium battery The core 3 is designed to work directly into an efficient operating state.

[0042] (2) When the ambient temperature is situated ² 0-30 ° C

[0043] 1) If the lithium battery cell 3 is in the process of charging and discharging, the heat generated by the lithium battery cell 3 is first transmitted to the gas-liquid phase change heat conduction channel 2 through the column 22 and is diverged from the gas-liquid phase change heat conduction channel 2, The heat of the helium is transferred from the gas-liquid phase to the heat-conducting channel 2 to the surrounding solid-liquid phase change energy storage body 1, and the solid-liquid phase change energy storage body 1 absorbs heat in the working temperature range of each phase change material until the solid-liquid phase changes energy storage. The temperature of the body 1 reaches 35 ° C, and the materials in the low temperature zone and the medium temperature zone are all converted into a liquid phase, and the ability of the entire solid-liquid phase change energy storage body 1 to continue to store heat is weakened, and the BMS detects the solid-liquid phase change energy storage body. The temperature of 1 reaches 35 °C, and the cooling mode of the vehicle air conditioning system is started. The vehicle air conditioning system exchanges heat with the gas-liquid phase heat conduction channel 2 through the vehicle cold heat exchanger 4, and accelerates the heat generated by the lithium battery core 3 from the gas phase. The variable heat conduction channel 2 is led out, thereby preventing the temperature of the lithium battery cell 3 from continuing to rise.

[0044] 2) If the lithium battery cell 3 is in the deactivated state, the ambient temperature can keep the temperature of the lithium battery cell 3 within 20-30 ° C, and the lithium battery cell 3 can directly enter the high-efficiency operation state after the next working.

[0045] (3) When the ambient temperature is higher than 30 ° C

[0046] 1) If the lithium battery cell 2 is in the process of charging and discharging, the heat generated by the lithium battery cell 3 is first transmitted to the gas-liquid phase change heat conduction channel 2 through the column 22 and is diverged from the gas-liquid phase change heat conduction channel 2, The heat of the helium is transferred from the gas-liquid phase to the heat-conducting channel 2 to the surrounding solid-liquid phase change energy storage body 1, and the solid-liquid phase change energy storage body 1 absorbs heat in the working temperature range of each phase change material until the solid-liquid phase changes energy storage. The temperature of the body 1 reaches 40 ° C, and the materials in the low temperature zone and the medium temperature zone are all converted into a liquid phase, and a part of the material in the high temperature zone has also been converted into a liquid. Phase, the ability of the entire solid-liquid phase change energy storage body 1 to continue to store heat is weakened, and the BMS detects that the temperature of the solid-liquid phase change energy storage body 1 reaches 40 ° C. The cooling mode of the vehicle air conditioning system is started, and the vehicle air conditioning system is cooled by the vehicle. The heat exchanger 4 exchanges heat with the gas-liquid phase change heat conduction passage 2 to accelerate the heat generated by the lithium battery core 3 from the gas-liquid phase change heat conduction passage 2, thereby preventing the temperature of the lithium battery core 3 from continuing to rise.

[0047] 2) If the lithium battery cell 3 is in a deactivated state, the surrounding environment continuously transfers heat to the lithium battery cell 3 through the gas-liquid phase change heat conduction channel 2, and the solid-liquid phase change energy storage body 1 is changed in each phase. The heat is absorbed in the working temperature range of the material, thereby slowing down the temperature rise of the lithium battery cell 3, until the temperature of the solid-liquid phase change energy storage body 1 reaches 45 ° C, and all the phase change materials have been converted into a liquid phase, and the whole solid-liquid phase change The energy storage body 1 cannot continue to store heat, and the BMS detects that the temperature of the solid-liquid phase change energy storage body 1 reaches 45 ° C. The cooling mode of the vehicle air conditioning system is started, and the vehicle air conditioning system passes through the vehicle cold heat exchanger 4 and the gas liquid phase change. The heat conduction channel 2 performs heat exchange, and accelerates the heat in the lithium battery core 3 from the gas-liquid phase change heat conduction channel 2, thereby preventing the temperature of the lithium battery core 3 from continuing to rise and exceeding the operating temperature limit value of the lithium battery core by 45 °C.

[0048] In all cases, when it is required to activate the vehicle air conditioning system, if the BMS detects that the lithium battery cell 3 is in a discharged or deactivated state, the vehicle air conditioning system is controlled to be powered by the vehicle power system of the electric vehicle; if the BMS detects When the lithium battery cell 3 is in a charging state, the vehicle air conditioning system is controlled to be powered by the charging post.

Table 1

[] [Table 1]

It is apparent that the above-described embodiments are merely illustrative of the invention and are not intended to limit the embodiments of the invention. Other variations or modifications of the various forms may be made by those skilled in the art in light of the above description. There is no need and no way to exhaust all of the implementations. And these obvious changes or changes that extend to the spirit of the present invention are still in this Within the scope of protection of the invention.

Claims

Claim

[Claim 1] A multi-phase phase change heat balance system for an electric vehicle lithium battery package, comprising: a gas-liquid phase change heat conduction channel (2) containing a gas-liquid phase change material, and a gas-liquid phase change heat conduction channel (2) including at least An extension channel (21) and a cylinder (22) for accommodating the lithium battery cell (3), the hollow wall of all the cylinders (22) is in communication with the extension channel (21), and the outer wall of the lithium battery cell (3) is suitable Heat transfer to the inner wall of the cylinder (22).

[Claim 2] The multiphase phase change heat balance system according to claim 1, wherein: each of the columns (22

There is a solid-liquid phase change energy storage body (1) on the outer side of the circumference, and the solid-liquid phase change energy storage body (1) contains at least three groups, and each group of solid-liquid phase change energy storage bodies (1) contains different work. The solid-liquid phase change materials in the temperature range are: solid-liquid phase change material with working temperature range of 10~20 °C, solid-liquid phase change material with working temperature range of 20~30 °C and working temperature range of 35~ Solid-liquid phase change material at 45 °C.

[Claim 3] The multi-phase phase change heat balance system according to claim 2, wherein: in the solid-liquid phase change mixture, the solid-liquid phase change material having an operating temperature range of 10 to 20 ° C accounts for 30%. Solid-liquid phase change materials with an operating temperature range of 20 to 30 ° C account for 40%, and solid-liquid phase change materials with an operating temperature range of 35 to 45 ° C account for 30%.

[Claim 4] The multi-phase phase change heat balance system according to any one of claims 1-3, characterized in that: the extended end of the extension channel (21) is provided with a vehicle-mounted cold heat exchanger (4), and the vehicle is cooled. The heat exchanger (4) is adapted for heat exchange with a vehicle air conditioning system.

[Claim 5] The multi-phase phase change heat balance system according to claim 4, wherein the on-vehicle cold heat exchanger (4) comprises a plurality of heat transfer fins (41) and a heat transfer tube (42), The heat sheets (41) are parallel to each other, and the extending passages (21) pass through the heat transfer sheets (41) and are heat-transferred to the heat transfer sheets (41), and the heat transfer tubes (42) pass through the respective heat transfer sheets (41). And heat transfer connection with each heat transfer sheet (41), the heat transfer tube (42) is connected to the heat transfer connection of the vehicle air conditioning system.

[Claim 6] The multi-phase phase change heat balance system according to claim 1, wherein: the multi-phase phase change heat balance system further comprises a heat balance processing unit, wherein the heat balance processing unit comprises: an ECU connected to the electric vehicle a controller, a plurality of temperature sensors connected to the controller; the controller is adapted to collect an ambient temperature, a temperature of the gas-liquid phase change material, and a solid by the temperature sensor The liquid phase changes the temperature of the energy storage body (1), and the controller controls the vehicle air conditioning system and the vehicle power system of the electric vehicle through the ECU.

A method of operation using the multiphase phase change heat balance system of claim 6 characterized by comprising:

When the temperature of the lithium battery (3) rises, the lithium battery (3) conducts heat to the solid-liquid phase change energy storage body (1) through the gas-liquid phase heat transfer channel (2), and the solid-liquid phase change energy storage body (1) Heat absorption When the temperature of the solid-liquid phase change energy storage body (1) is detected to reach the set upper limit value, the cooling mode of the vehicle air conditioning system is started, and the vehicle air conditioning system passes the vehicle cold heat exchanger (4), gas liquid phase The variable heat conduction channel (2) exchanges heat with the lithium battery cell (3).

The method for operating a multi-phase phase change heat balance system according to claim 7, wherein: when the temperature of the lithium battery cell (3) drops to a lower limit value, the solid-liquid phase change energy storage body (1) emits heat and Passing the gas-liquid phase variable heat conduction channel (2) to the lithium battery cell (3), when the temperature of the solid-liquid phase change energy storage body (1) is detected to reach the set lower limit value again, the heating mode of the vehicle air conditioning system is started. , car air conditioning system through the vehicle cold heat exchanger, gas-liquid phase change heat conduction channel

(2) Heat exchange with lithium battery (3).

The method for operating a multi-phase phase change heat balance system according to claim 7, wherein: when the ambient temperature is lower than 20 ° C, the upper limit of the temperature setting is 30 ° C, and the lower limit is 10 ° C. When the ambient temperature is at 20-30 °C, the upper limit of the temperature setting is 35 °C, no lower limit is set; When the ambient temperature is higher than 30 °C, if the lithium battery is in charge and discharge, the temperature is set. The upper limit is 40 °C, otherwise the upper limit of the temperature setting is 45 °C, there is no lower limit;

When the car air conditioning system is activated, if the lithium battery (3) is in a discharged or deactivated state, the car air conditioning system is powered by the vehicle's onboard power system; if the lithium battery (3) is in the charging state, the car air conditioning system is powered by the charging post.

An electric vehicle, comprising a lithium battery package, characterized in that the lithium battery package adopts the multi-phase phase change heat balance system according to any one of claims 1-3.