New energy automobile battery thermal management system

Abstract

The invention belongs to the field of new energy automobiles, and provides a new energy automobile battery thermal management system which comprises a battery pack, three groups of battery cells, a liquid cooling plate assembly, an electric heating element, a water pump, a battery cooler, an evaporator, a fan, a compressor, an outdoor condenser and an expansion valve. One water outlet of the mercury type thermostat is communicated with the battery cooler, the other water outlet of the mercury type thermostat is provided with a flow control valve through a pipeline, and the liquid cooling plate assembly comprises a lower liquid cooling plate, three relatively independent upper liquid cooling plates, a water inlet pipe opening and a water outlet pipe opening. And an upper water pipe plug-in and a lower water pipe plug-in are arranged between the upper liquid cooling plate and the lower liquid cooling plate. The battery pack shell is reasonable in design, beneficial to energy conservation, beneficial to improvement of heat dissipation performance in the battery pack shell, beneficial to guarantee of real-time working performance of the battery cells, beneficial to prolonging of the actual service life of the battery cells and suitable for large-scale popularization.

Description

Technical Field

[0001] The present invention belongs to the field of new energy vehicles, and in particular relates to a new energy vehicle battery thermal management system. Background Art

[0002] With the rise of the new energy vehicle technology industry, as its energy source, power batteries have become one of the important indicators to measure the performance of new energy vehicles, and the heat dissipation performance of power batteries is directly related to the working efficiency and service life of power batteries. Battery thermal management is part of the thermal management system of new energy vehicles. In addition, the thermal management system of the vehicle also includes thermal management of motors and electronic control systems, and thermal management of the cabin. The battery thermal management system is a system that ensures that the battery pack can be kept within the appropriate temperature range under various environmental conditions and working conditions. Its main function is to heat or cool the battery so that the battery can work efficiently, safely and reliably.

[0003] The existing patent CN209150271U discloses a battery thermal management system, which includes a battery water cooling plate, a heater, a water pump and a battery cooling water circuit connected in series in sequence; wherein, the battery water cooling plate generally adopts an upper and lower two-layer design, and the battery cell is arranged between the battery water cooling plates, but for the front and rear ends of the battery cell, many wirings will also generate a lot of heat during the working process, and the water cooling range of the battery water cooling plate does not involve the line range, which is not conducive to the internal heat dissipation of the battery pack; furthermore, the thermostats used in the field of fuel engines are basically wax thermostats, and the valve control mechanism temperature of the wax thermostat is above 70 degrees, and the suitable working temperature of the battery is 0-40 degrees Celsius, so there are not many applications in pure electric vehicles, especially in battery cooling cycles, and the cooling cycle relies more on the feedback of the temperature sensor, and it is inevitable that there is a feedback time difference and adjustment lag, which affects the real-time working performance and actual service life of the battery cell. Summary of the invention

[0004] In view of the technical problems existing in the battery thermal management of the above-mentioned pure electric vehicles, the present invention proposes a new energy vehicle battery thermal management system which has a reasonable design, is beneficial to energy saving, is beneficial to improving the heat dissipation performance inside the battery pack shell, is beneficial to ensuring the real-time working performance of the battery cell and is beneficial to extending its actual service life.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is that a new energy vehicle battery thermal management system provided by the present invention includes a battery pack, wherein three groups of battery cells and a liquid cooling plate assembly are arranged inside the battery pack, an electric heating element is arranged on the water inlet side of the liquid cooling plate assembly, and a water pump and a battery cooler are also arranged on the water inlet side and the water outlet side of the liquid cooling plate assembly. An evaporator, a fan, a compressor, an outdoor condenser and an expansion valve are arranged on the medium circulation side of the battery cooler, a mercury thermostat located on the water outlet side of the liquid cooling plate assembly is arranged inside the battery pack, one water outlet of the mercury thermostat is connected to the battery cooler, and the other water outlet of the mercury thermostat is connected to the battery cooler through a pipe A flow control valve is provided, and the flow control valve is arranged on the communication path between the battery cooler and the water pump. The liquid cooling plate assembly includes a lower liquid cooling plate, and relatively distributed water inlet and outlet pipes are arranged on the side of the lower liquid cooling plate. Three relatively independent upper liquid cooling plates connected with the lower liquid cooling plate are arranged above the lower liquid cooling plate. An upper water pipe plug-in and a lower water pipe plug-in are arranged between the upper liquid cooling plate and the lower liquid cooling plate. The upper water pipe plug-in is distributed near the water inlet pipe direction, and the lower water pipe plug-in is distributed near the water outlet pipe direction. One end of the lower liquid cooling plate is provided with a water outlet channel connected with the lower water pipe plug-in and blocked from the water inlet end of the upper water pipe plug-in, and the water outlet channel is connected with the water outlet pipe.

[0006] Preferably, the upper water pipe plug-in includes an upper jellyfish plug fixedly connected to the lower liquid cooling plate, the upper jellyfish plug includes 4 upper water sockets arranged in a straight line, the upper water pipe plug-in also includes 4 upper water intubations fixedly connected to the upper liquid cooling plate, the lower water pipe plug-in includes a lower jellyfish plug fixedly connected to the lower liquid cooling plate, the lower jellyfish plug includes 4 lower water sockets arranged in a straight line, and the lower water pipe plug-in also includes 4 lower water intubations fixedly connected to the upper liquid cooling plate.

[0007] Preferably, the water supply pipe and the water discharge pipe are both stepped structures, the lower half of the water supply pipe and the lower half of the water discharge pipe are respectively plugged into the upper jellyfish plug and the lower jellyfish plug, and the lower half of the water supply pipe and the lower half of the water discharge pipe are both provided with a plurality of vertically spaced annular grooves, and the annular grooves are used to install O-rings.

[0008] Preferably, the lengths of the upper water pipe plug-in and the lower water pipe plug-in are both less than 1 / 2 of the width of the battery cell.

[0009] Preferably, the upper liquid cooling plate includes two side cooling channels symmetrically distributed on the left and right, the water inlet end of the side cooling channel is led out from an upper water socket on the side of the upper liquid cooling plate and extends in an S-shape to a lower water socket, and an intermediate cooling channel is arranged between the two side cooling channels of the same upper liquid cooling plate, the central trajectory of the intermediate cooling channel is U-shaped and the middle part thereof is simultaneously connected to the two upper water sockets in the middle of the upper liquid cooling plate, and the U-shaped ends of the intermediate cooling channel are respectively connected to the two lower water sockets.

[0010] Preferably, the lower liquid cooling plate is provided with two structural holes spaced apart from the battery cells, the lower liquid cooling plate is provided with a plurality of sheet metal grooves at positions corresponding to the upper and lower portions of the battery cells, and a liquid cooling channel is formed inside the lower liquid cooling plate around the sheet metal grooves.

[0011] Preferably, the mercury thermostat includes a tube shell, the tube shell includes 1 inlet and 2 outlets, the center direction of the outlet on the tube shell connected to the battery cooler is parallel to the center direction of the inlet, the center direction of the outlet on the tube shell connected to the flow control valve intersects with the center direction of the inlet at an acute angle, a thermostat component is arranged inside the tube shell, a mercury filling cavity is arranged inside the thermostat component, the mercury filling cavity is filled with mercury, the cross-section of the mercury filling cavity is U-shaped, and the outer wall of the mercury filling cavity is provided with a plurality of pipeline medium contact grooves distributed in a circular array.

[0012] Preferably, the thermostat assembly includes a thermostat support, a first valve member axially movably engaged with the thermostat support is arranged at the center of the thermostat support, a directional shaft axially movably engaged with the first valve member is arranged at the center of the first valve member, a reduced diameter blind hole corresponding to the mercury filling chamber is arranged at the center of the directional shaft, the first valve member is provided with a second valve member at one end thereof facing away from the directional shaft, the second valve member is movably engaged with an outlet of the tube shell, and a first spring and a second spring are respectively arranged between the first valve member and the inside of the thermostat support and between the second valve member and the outside of the thermostat support.

[0013] Preferably, the second valve member comprises a valve stem, a valve slot cover is provided at the bottom of the valve stem, a side cover surface of the valve slot cover is in an inverted cone shape, and a trumpet-shaped bushing matching with the valve slot cover is provided inside the tube shell.

[0014] Preferably, the tube shell includes a first shell body and a second shell body which are threadedly connected, a positioning piece which cooperates with a thermostat support piece is arranged inside the first shell, and a clamping piece which is buckled with the positioning piece is arranged at one end of the positioning piece facing the second shell, and the clamping piece and the positioning piece are matched through buckle grooves and buckle teeth, and the clamping piece, the positioning piece and the thermostat support piece are nested.

[0015] Compared with the prior art, the advantages and positive effects of the present invention are:

[0016] 1. The present invention provides a new energy vehicle battery thermal management system. The mercury thermostat uses mercury as a temperature-sensitive medium to control the opening of its different outlets. Combined with the flow control function of the flow control valve, the liquid flow flowing out of the battery pack and passing through the battery cooler can be adjusted in real time. This not only ensures the stability of the water pump output, but also reduces the workload of the evaporator, fan and outdoor condenser, thereby achieving energy-saving effects.

[0017] 2. The present invention provides a new energy vehicle battery thermal management system, which utilizes an upper water pipe plug-in and a lower water pipe plug-in to establish a flow path for the upper liquid cooling plate and the lower liquid cooling plate, thereby establishing a pipeline condition capable of exchanging heat at the front and rear ends of the battery cell, and in particular can improve the heat dissipation effect of the working circuit in the wiring range, thereby facilitating the improvement of the heat dissipation performance inside the battery pack, and also facilitating the guarantee of the real-time working performance of the battery cell and extending its actual service life, and is suitable for large-scale promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 A schematic diagram of the structure of a new energy vehicle battery thermal management system provided in an embodiment;

[0020] Figure 2 A front view of a liquid cooling plate assembly provided in an embodiment;

[0021] Figure 3 An axonometric view of an upper liquid cooling plate provided in an embodiment;

[0022] Figure 4 An axonometric view of a lower liquid cooling plate provided in an embodiment;

[0023] Figure 5 A top view of a liquid cooling plate assembly provided in an embodiment;

[0024] Figure 6 A cross-sectional view of a mercury thermostat provided in an embodiment;

[0025] Figure 7 A schematic diagram of the external structure of a mercury thermostat provided in an embodiment;

[0026] Figure 8 An axonometric view of a mercury thermostat provided for an embodiment;

[0027] Fig. 9A front view of a mercury thermostat provided in an embodiment;

[0028] In the above figures:

[0029] 1. Battery pack;

[0030] 2. Battery cells;

[0031] 3. Liquid cooling plate assembly; 31. Lower liquid cooling plate; 311. Water inlet; 312. Water outlet; 313. Structural hole; 314. Sheet metal groove; 32. Upper liquid cooling plate; 321. Side cooling channel; 322. Middle cooling channel; 33. Upper water pipe plug-in; 331. Upper jellyfish plug-in; 332. Upper water socket; 333. Upper water inlet; 34. Lower water pipe plug-in; 341. Lower jellyfish plug-in; 342. Lower water socket; 343. Lower water inlet; 35. Water outlet channel; 36. Annular groove;

[0032] 4. Electric heating element;

[0033] 5. Water pump;

[0034] 6. Battery cooler;

[0035] 7. Evaporator;

[0036] 8. Fan;

[0037] 9. Compressor;

[0038] 10. Outdoor condenser;

[0039] 11. Expansion valve;

[0040] 12. Mercury thermostat; 121. Tube shell; 1211. Inlet; 1212. Outlet; 1213. First shell; 1214. Second shell; 122. Thermostat assembly; 1221. Mercury filling cavity; 1222. Pipe medium contact groove; 1223. Thermostat support; 1224. First valve member; 1225. Orienting shaft; 1226. Reduced diameter blind hole; 1227. Second valve member; 12271. Valve stem; 12272. Valve slot cover; 1228. First spring; 1229. Second spring; 123. Trumpet bushing; 124. Positioning member; 125. Pressing member; 126. Buckle groove; 127. Buckle teeth;

[0041] 13. Flow control valve. DETAILED DESCRIPTION

[0042] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described below in conjunction with the accompanying drawings and embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict. For the convenience of description, if the words "upper", "lower", "left" and "right" appear below, they only indicate that the upper, lower, left and right directions are consistent with the accompanying drawings themselves, and do not limit the structure.

[0043] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways than those described herein. Therefore, the present invention is not limited to the specific embodiments of the following disclosure.

[0044] Examples, such as Figure 1-Figure 9 As shown, a new energy vehicle battery thermal management system provided by the present invention includes a battery pack 1, wherein three groups of battery cells 2 and a liquid cooling plate assembly 3 are arranged inside the battery pack 1, each group of battery cells 2 includes 32 battery cells, so the three groups of battery cells have a total of 96 battery cells, an electric heating element 4 is arranged on the water inlet side of the liquid cooling plate assembly 3, a water pump 5 and a battery cooler 6 are also arranged on the water inlet side and the water outlet side of the liquid cooling plate assembly 3, and an evaporator 7, a fan 8, a compressor 9, an outdoor condenser 10 and an expansion valve 11 are arranged on the medium circulation side of the battery cooler 6. Among them, the electric heating element 4 is used to heat the circulating medium in the liquid cooling plate assembly 3 in winter and under cold start conditions to ensure the starting performance of the pure electric vehicle; other structures such as the battery cooler 6, the evaporator 7, the fan 8, the compressor 9, the outdoor condenser 10 and the expansion valve 11 and the connection route are existing mature technologies, and this embodiment will not be repeated here.

[0045] On this basis, the battery pack 1 provided by the present invention is provided with a mercury thermostat 12 located on the water outlet side of the liquid cooling plate assembly 3, one water outlet of the mercury thermostat 12 is connected to the battery cooler 6, and the other water outlet of the mercury thermostat 12 is provided with a flow control valve 13 through a pipeline, and the flow control valve 13 is preset at a stable flow value, and the flow control valve 13 is arranged on the communication path between the battery cooler 6 and the water pump 5, and the liquid cooling plate assembly 3 includes a lower liquid cooling plate 31, and the side of the lower liquid cooling plate 31 is provided with relatively distributed water inlet pipes 3 11 and a water outlet pipe port 312, three relatively independent upper liquid cooling plates 32 connected to the lower liquid cooling plate 31 are arranged above the lower liquid cooling plate 31, an upper water pipe plug-in 33 and a lower water pipe plug-in 34 are arranged between the upper liquid cooling plate 32 and the lower liquid cooling plate 31, the upper water pipe plug-in 33 is distributed near the water inlet pipe port 311, and the lower water pipe plug-in 34 is distributed near the water outlet pipe port 312, and one end of the lower liquid cooling plate 31 is provided with a water outlet channel 35 connected to the lower water pipe plug-in 34 and blocked from the water inlet end of the upper water pipe plug-in 33, and the water outlet channel 35 is connected to the water outlet pipe port 312.

[0046] Specifically, the mercury thermostat 12 uses mercury as a temperature-sensitive medium, which is more sensitive to temperature than the wax thermostat, and can react at all temperatures when the battery pack 1 is under working conditions, thereby adjusting the opening of the two different outlets 1212 of the mercury thermostat 12. Specifically, if the temperature of the battery cell inside the battery pack 1 is less than 25°C to 40°C, the connection path between the mercury thermostat 12 and the flow control valve 13 is in a connected state, so most of the fluid of the liquid cooling plate assembly 3 can be directly circulated in the liquid cooling plate assembly 3, the water pump 5 and the mercury thermostat 12. In addition, the flow control function of the flow control valve 13 can adjust the liquid flow flowing out of the battery pack 1 and passing through the battery cooler 6 in real time, and the water flow of the water pump 5 is also kept stable; while the medium circulation flow on the side where the battery cooler 6 is located and the workload of the fan 8 and the compressor 9 are in a relatively low state, which has a positive significance for energy saving. If the temperature of the battery cell inside the battery pack 1 is greater than 40°C, the connection path between the mercury thermostat 12 and the flow control valve 13 is disconnected, and the mercury thermostat 12 and the battery cooler 6 are kept fully open, so the fluid medium in the liquid cooling plate assembly 3 all passes through the battery cooler 6, and the evaporator 7 on the battery cooler 6 side also enters normal load operation, thereby ensuring the cooling effect of the liquid in the battery cooling cycle, and then controlling the operating temperature of the battery cell inside the battery pack 1 to drop below 40°C, thereby ensuring the real-time working performance of the battery cell.

[0047] Furthermore, in the liquid cooling plate assembly 3 provided by the present invention, an upper water pipe plug-in 33 and a lower water pipe plug-in 34 are used to establish a flow path for the upper liquid cooling plate 32 and the lower liquid cooling plate 31, and at the same time, the upper water pipe plug-in 33 and the lower water pipe plug-in 34 also leave sufficient wiring space for both ends of the battery cell. On the one hand, the liquid medium in the liquid cooling plate assembly 3 can enter from the water inlet pipe port 311 and be distributed to the entire lower liquid cooling plate 31, and then be distributed to different upper liquid cooling plate 32 assemblies 3 from the upper water pipe plug-in 33. The end of the upper liquid cooling plate 32 assembly 3 discharges the liquid medium to the water outlet channel 35 through the lower water pipe plug-in 34, and then is discharged from the water outlet pipe port 312, thereby establishing a pipeline condition for the circulation flow of the liquid medium; on the other hand, liquid medium has passed through both the upper water pipe plug-in 33 and the lower water pipe plug-in 34, thereby establishing a pipeline condition that can exchange heat at the front and rear ends of the battery cell 2, especially improving the heat dissipation effect of the working circuit in the wiring range at both ends of the battery cell 2, thereby facilitating improving the heat dissipation performance inside the battery pack 1, and also facilitating ensuring the real-time working performance of the battery cell and extending its actual service life.

[0048] like Figure 2-Figure 5As shown, the upper water pipe plug-in 33 provided by the present invention includes an upper jellyfish plug-in 331 fixedly connected to the lower liquid cooling plate 31, the upper jellyfish plug-in 331 includes four upper water sockets 332 arranged in a straight line, the upper water pipe plug-in 33 also includes four upper water inlets 333 fixedly connected to the upper liquid cooling plate 32, the lower water pipe plug-in 34 includes a lower jellyfish plug-in 341 fixedly connected to the lower liquid cooling plate 31, the lower jellyfish plug-in 341 includes four lower water sockets 342 arranged in a straight line, and the lower water pipe plug-in 34 also includes four lower water inlets 343 fixedly connected to the upper liquid cooling plate 32. Among them, the upper water pipe plug-in 33 divides an upper water jellyfish plug 331 into four upper water sockets 332 to connect with the upper water plug 333. By reducing the connection diameter, the pressure of water flowing from bottom to top into the upper liquid cooling plate 32 can be increased, and it is ensured that a reasonable number of branches can be divided from the upper liquid cooling plate 32 to fill the upper liquid cooling plate 32. Different branches are connected to different lower water sockets 342, which is convenient for guiding the liquid medium to the circulation path without stagnation in the upper liquid cooling plate 32. In addition, the heat conduction effect of the plate material of the liquid cooling plate 32 itself can effectively improve the overall heat dissipation effect of the liquid cooling plate assembly 3 on the battery cell.

[0049] In order to improve the connection sealing performance of the upper water pipe plug-in 33 and the lower water pipe plug-in 34, the upper water plug-in 333 and the lower water plug-in 343 provided by the present invention are both stepped structures, and the lower half of the upper water plug-in 333 and the lower water plug-in 343 are respectively plugged with the upper jellyfish plug-in 331 and the lower jellyfish plug-in 341, and are preferably aligned with the roots of the upper jellyfish plug-in 331 and the lower jellyfish plug-in 341; at the same time, the lower half of the upper water plug-in 333 and the lower water plug-in 343 are both provided with a plurality of annular grooves 36 distributed vertically at intervals, and the annular grooves 36 are used to install O-type sealing rings. In this way, on the basis of increasing the sealing area by plugging in the upper water pipe plug-in 33 and the lower water pipe plug-in 34, multiple O-type sealing rings are also provided as elastic seals, which increases the resistance of the liquid medium overflowing the docking surface and effectively ensures the sealing performance of the liquid medium in the upper and lower connection paths.

[0050] Considering that there are many connections at both ends of the battery cell, in order not to affect the connections at both ends of the battery cell, the length of the upper water pipe plug-in 33 and the lower water pipe plug-in 34 provided by the present invention are both less than 1 / 2 of the width of the battery cell. The upper water pipe plug-in 33 and the lower water pipe plug-in 34 also leave sufficient connection space for both ends of the battery cell. For some connections, due to the limited internal space of the battery pack 1, some connections can be connected with the upper water pipe plug-in 33 and the lower water pipe plug-in 34 in a reasonable wiring manner, thereby achieving the purpose of heat conduction and heat dissipation.

[0051] In order to improve the distribution effect of the liquid medium in the upper liquid cooling plate 32, matching the horizontal lengths of the upper water pipe plug-in 33 and the lower water pipe plug-in 34, the upper liquid cooling plate 32 provided by the present invention includes two side cooling channels 321 that are symmetrically distributed on the left and right. The water inlet end of the side cooling channel 321 is led out from an upper water socket 332 on the side of the upper liquid cooling plate 32 and extends in an S-shaped circuitous manner to a lower water socket 342. A middle cooling channel 322 is arranged between the two side cooling channels 321 of the same upper liquid cooling plate 32. The central trajectory of the middle cooling channel 322 is U-shaped and the middle part thereof is simultaneously connected to the two upper water sockets 332 in the middle of the upper liquid cooling plate 32. The U-shaped ends of the middle cooling channel 322 are respectively connected to the two lower water sockets 342. Among them, the upper water socket 332 and the lower water socket 342 are close to the middle position of the upper liquid cooling plate 32. The circuitous extension of the side cooling channel 321 can ensure that there is a channel with sufficient area and length for the liquid medium to flow through, and one middle cooling channel 322 is used to connect the two upper water sockets 332 and the two lower water sockets 342 at the same time. The flow path of the liquid medium in the side cooling channel 321 is long, which can ensure the adequacy of the heat conduction and heat exchange of the liquid medium; the flow path of the liquid medium in the middle cooling channel 322 is short, and its U-shaped two sides are connected to each other, with good water flow effect and not easy to be blocked. It can ensure that the water flow source has a small power and can maintain a certain fluidity to ensure the actual heat dissipation effect of the liquid cooling plate assembly 3.

[0052] To match the three groups of battery cells, the lower liquid cooling plate 31 provided by the present invention is provided with two structural holes 313 that are spaced apart from the battery cells. The lower liquid cooling plate 31 is provided with a plurality of sheet metal grooves 314 at positions corresponding to the upper and lower portions of the battery cells. The interior of the lower liquid cooling plate 31 forms a liquid cooling flow channel that is blocked from the water outlet channel 35 around the sheet metal grooves 314. The liquid cooling flow channels at the left, middle and right positions of the lower liquid cooling plate 31 are all kept connected, which is beneficial for distributing the liquid cooling medium from the lower liquid cooling plate 31 to the three upper liquid cooling plates 32 that are in a relatively independent relationship.

[0053] like Figure 6-Figure 9As shown, the mercury thermostat 12 includes a tube shell 121, and the tube shell 121 includes an inlet 1211 and two outlets 1212. The center direction of the outlet 1212 on the tube shell 121 connected to the battery cooler 6 is parallel to the center direction of the inlet 1211, and the center direction of the outlet 1212 on the tube shell 121 connected to the flow control valve 13 intersects with the center direction of the inlet 1211 at an acute angle. A thermostat component 122 is arranged inside the tube shell 121, and a mercury filling cavity 1221 is arranged inside the thermostat component 122. The mercury filling cavity 1221 is filled with mercury, and the cross-section of the mercury filling cavity 1221 is U-shaped. The outer wall of the mercury filling cavity 1221 is provided with a plurality of pipeline medium contact grooves 1222 distributed in a circular array. If the outlet 1212 connected to the battery cooler 6 is kept parallel to the inlet 1211 of the tube shell 121, it is beneficial for the inlet and outlet directions of the tube shell 121 to maintain good connection performance after the battery cell temperature is greater than 45°C. The wall thickness of the corresponding position of the mercury filling cavity 1221 and the pipeline medium contact groove 1222 is relatively small, which can improve the instantaneous expansion of mercury due to heat.

[0054] Furthermore, the thermostat assembly 122 provided by the present invention includes a thermostat support 1223, a first valve member 1224 is arranged at the center of the thermostat support 1223 to cooperate with the thermostat support 1223, the first valve member 1224 and the thermostat support 1223 cooperate part is a solid part, the first valve member 1224 facing the second valve member 1227 is a hollow support structure; the first valve member 1224 is arranged at the center of the first valve member 1224 to cooperate with the thermostat support 1223, and the first valve member 1224 and the second valve member 1227 are hollow support structures. A reduced diameter blind hole 1226 corresponding to the mercury filling chamber 1221 is arranged in the center, a second valve component 1227 is arranged at the end of the first valve component 1224 facing away from the directional axis 1225, the second valve component 1227 is movably matched with an outlet 1212 of the tube shell 121, a first spring 1228 and a second spring 1229 are arranged between the first valve component 1224 and the inside of the thermostat support 1223, and between the second valve component 1227 and the outside of the thermostat support 1223, respectively. The first spring 1228 and the second spring 1229 play the role of elastic support and reset, and ensure the closing quality of the valve port where the first valve member 1224 and the valve port where the second valve member 1227 are located when reaching their respective closing conditions; the aperture of the reduced-diameter blind hole 1226 is significantly smaller than the cavity diameter of the mercury filling cavity 1221. On the one hand, such a design can allow mercury to quickly produce strain under heating conditions; on the other hand, in conjunction with the cross-sectional design of the mercury filling cavity 1221, it can ensure a more flexible mechanical action based on less usage.

[0055] Specifically, after the mercury expands due to heat, its expansion state causes the axial distance between the necked blind hole and the mercury filling cavity 1221 to lengthen, and the directional shaft 1225 remains in position under the pressure, but the first valve member 1224 and the second valve member 1227 will simultaneously produce axial displacement, especially the original closed surfaces of the first valve member 1224 and the thermostat support member 1223 will be staggered to leave a gap, and the fitting gap between the second valve member 1227 and the tube shell 121 will gradually be compressed; the continued expansion of mercury will cause the valve port of the first valve member 1224 to be completely opened, and the valve port of the second valve member 1227 to be completely closed, thereby completely redirecting the actual outlet 1212 of the fluid in the tube shell 121, thereby achieving the purpose of energy saving in the early stage of the battery cell operation, and also conducive to improving the starting efficiency of pure electric vehicles under cold start.

[0056] In order to ensure the control performance of the second valve component 1227, the second valve component 1227 provided by the present invention includes a valve stem 12271, a valve slot cover 12272 is provided at the bottom of the valve stem 12271, the side cover surface of the valve slot cover 12272 is inverted cone shape, and a trumpet-shaped bushing 123 with a double cone structure matching the valve slot cover 12272 is provided inside the tube shell 121. In this way, the valve port controlled by the second valve component 1227 under the mercury strain condition has a certain control gradient. In the process of mercury straining with temperature, the second valve component 1227 is slowly closed, and the gap of the valve port where it is located is gradually reduced. The continuity and stability of the entire cooling and heat exchange process are ensured through the gradual process, which is conducive to ensuring the working performance of the system.

[0057] In order to improve the utilization rate of the mercury thermostat 12, in addition to the thermostat assembly 122, the tube shell 121 also adopts a detachable design. For example, the tube shell 121 includes a first shell 1213 and a second shell 1214 that are threaded together. The interior of the first shell 1213 is provided with a positioning piece 124 that cooperates with the thermostat support 1223. The positioning piece 124 is provided with a clamping piece 125 that is buckled with the second shell 1214 at one end thereof facing the second shell 1214. The clamping piece 125 and the positioning piece 124 are matched through buckling grooves and buckling teeth, and the clamping piece 125, the positioning piece 124 and the thermostat support 1223 are nested. In this case, the thermostat assembly 122 can be fixed on the positioning member 124 by means of press-fitting, and the buckle groove 126 and the buckle teeth 127 are used for quick buckling, so that the pressing member 125, the positioning member 124 and the thermostat support member 1223 are installed in order to establish a reasonable nesting relationship, thereby ensuring the installation reliability of the thermostat assembly 122; at the same time, the first shell 1213 and the second shell 1214 can be quickly installed and disassembled through threaded connection, which is convenient for assembling the thermostat assembly 122. The outlet 1212 and the inlet 1211 of the tube shell 121 can be connected to the corresponding pipelines in the system through nylon tubes. The nylon tubes have good physical, chemical and mechanical properties, are wear-resistant, have a smooth surface, can prevent rust and scale accumulation, and are soft, easy to bend, easy to install, and simple to process, which can meet the installation requirements of the mercury thermostat 12 inside the battery pack 1.

[0058] The above description is only a preferred embodiment of the present invention and does not limit the present invention in other forms. Any technician familiar with the profession may use the technical content disclosed above to change or modify it into an equivalent embodiment with equivalent changes and apply it to other fields. However, any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A new energy vehicle battery thermal management system, comprising a battery pack, wherein three groups of battery cells and a liquid cooling plate assembly are arranged inside the battery pack, an electric heating element is arranged on the water inlet side of the liquid cooling plate assembly, a water pump and a battery cooler are also arranged on the water inlet side and the water outlet side of the liquid cooling plate assembly, and an evaporator, a fan, a compressor, an outdoor condenser and an expansion valve are arranged on the medium circulation side of the battery cooler, characterized in that: A mercury thermostat located at the water outlet side of the liquid cooling plate assembly is arranged inside the battery pack, one water outlet of the mercury thermostat is communicated with the battery cooler, another water outlet of the mercury thermostat is provided with a flow control valve through a pipeline, and the flow control valve is arranged on the communication path between the battery cooler and the water pump, the liquid cooling plate assembly includes a lower liquid cooling plate, the side of the lower liquid cooling plate is provided with relatively distributed water inlet and outlet, three relatively independent upper liquid cooling plates connected to the lower liquid cooling plate are arranged above the lower liquid cooling plate, an upper water pipe plug-in and a lower water pipe plug-in are arranged between the upper liquid cooling plate and the lower liquid cooling plate, the upper water pipe plug-in is distributed near the direction of the water inlet, and the lower water pipe plug-in is distributed near the direction of the water outlet, one end of the lower liquid cooling plate is provided with a water outlet channel connected to the lower water pipe plug-in and blocked from the water inlet end of the upper water pipe plug-in, and the water outlet channel is connected to the water outlet.

2. A new energy vehicle battery thermal management system according to claim 1, characterized in that: The upper water pipe plug-in includes an upper jellyfish plug fixedly connected to the lower liquid cooling plate, the upper jellyfish plug includes 4 upper water sockets arranged in a straight line, the upper water pipe plug-in also includes 4 upper water intubations fixedly connected to the upper liquid cooling plate, the lower water pipe plug-in includes a lower jellyfish plug fixedly connected to the lower liquid cooling plate, the lower jellyfish plug includes 4 lower water sockets arranged in a straight line, and the lower water pipe plug-in also includes 4 lower water intubations fixedly connected to the upper liquid cooling plate.

3. A new energy vehicle battery thermal management system according to claim 2, characterized in that: The water supply pipe and the water discharge pipe are both stepped structures. The lower half of the water supply pipe and the lower half of the water discharge pipe are respectively plugged into the upper jellyfish plug and the lower jellyfish plug. The lower half of the water supply pipe and the lower half of the water discharge pipe are both provided with a plurality of annular grooves distributed vertically at intervals, and the annular grooves are used to install O-rings.

4. A new energy vehicle battery thermal management system according to claim 3, characterized in that: The lengths of the upper water pipe plug-in and the lower water pipe plug-in are both less than 1 / 2 of the width of the battery core.

5. A new energy vehicle battery thermal management system according to any one of claims 2 to 4, characterized in that: The upper liquid cooling plate includes two side cooling channels that are symmetrically distributed on the left and right. The water inlet end of the side cooling channel is led out from an upper water socket on the side of the upper liquid cooling plate and extends in an S-shape to a lower water socket. An intermediate cooling channel is arranged between the two side cooling channels of the same upper liquid cooling plate. The central trajectory of the intermediate cooling channel is U-shaped and the middle part thereof is connected to the two upper water sockets in the middle of the upper liquid cooling plate at the same time. The U-shaped ends of the intermediate cooling channel are respectively connected to the two lower water sockets.

6. A new energy vehicle battery thermal management system according to claim 1, characterized in that: The lower liquid cooling plate is provided with two structural holes spaced apart from the battery cells, and the lower liquid cooling plate is provided with a plurality of sheet metal grooves at positions corresponding to the upper and lower portions of the battery cells, and a liquid cooling channel is formed inside the lower liquid cooling plate around the sheet metal grooves.

7. A new energy vehicle battery thermal management system according to claim 1, characterized in that: The mercury thermostat includes a tube shell, the tube shell includes 1 inlet and 2 outlets, the center direction of the outlet on the tube shell connected to the battery cooler is parallel to the center direction of the inlet, the center direction of the outlet on the tube shell connected to the flow control valve intersects with the center direction of the inlet at an acute angle, a thermostat component is arranged inside the tube shell, a mercury filling cavity is arranged inside the thermostat component, the mercury filling cavity is filled with mercury, the cross-section of the mercury filling cavity is U-shaped, and the outer wall of the mercury filling cavity is provided with a plurality of pipeline medium contact grooves distributed in a circular array.

8. A new energy vehicle battery thermal management system according to claim 7, characterized in that: The thermostat assembly includes a thermostat support, a first valve member axially movably matched with the thermostat support is arranged at the center of the thermostat support, a directional shaft axially movably matched with the first valve member is arranged at the center of the first valve member, a reduced-diameter blind hole corresponding to the mercury filling chamber is arranged at the center of the directional shaft, the first valve member is provided with a second valve member at one end thereof facing away from the directional shaft, the second valve member is movably matched with an outlet of the tube shell, and a first spring and a second spring are respectively arranged between the first valve member and the inside of the thermostat support, and between the second valve member and the outside of the thermostat support.

9. A new energy vehicle battery thermal management system according to claim 8, characterized in that: The second valve member comprises a valve stem, a valve slot cover is arranged at the bottom of the valve stem, a side cover surface of the valve slot cover is in an inverted cone shape, and a trumpet-shaped bushing matched with the valve slot cover is arranged inside the tube shell.

10. A new energy vehicle battery thermal management system according to claim 9, characterized in that: The tube shell includes a first shell body and a second shell body which are threadedly connected. A positioning piece which cooperates with a thermostat support piece is arranged inside the first shell body. A clamping piece which is buckled with the positioning piece is arranged at one end of the positioning piece facing the second shell body. The clamping piece and the positioning piece are matched through buckle grooves and buckle teeth. The clamping piece, the positioning piece and the thermostat support piece are nested.

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