An electric vehicle water-cooling plate performance test bench and data processing method

Abstract

The application discloses a kind of electric vehicle water-cooled plate performance test platform and data processing method, the test platform includes two circuits of cooling liquid circuit and refrigerant circuit, including heat pump air conditioning system, low-temperature radiator cooling system, data acquisition and control system and water-cooled plate test bench, heat pump air conditioning system includes compressor, condensing / evaporating radiator, four-way valve, electronic expansion valve and plate heat exchanger, and heating and refrigeration are realized by four-way valve Switching;Low-temperature radiator cooling system includes water-cooled radiator, three-way valve and liquid storage tank, water-cooled radiator, three-way valve and liquid storage tank are connected to form cooling liquid circuit and refrigerant circuit is exchanged with cooling liquid circuit by plate heat exchanger, and the performance experiment of low-temperature radiator to water-cooled plate test platform can be realized.This application can simulate the actual operating performance of water-cooled plate on real electric vehicle, can test the heat dissipation and heating capacity of water-cooled plate, and can determine the pressure drop or flow resistance under different flow and different temperature.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of water-cooled plates for electric vehicles, in particular, to a water-cooled plate performance test bench for electric vehicle battery thermal management and a data processing method. BACKGROUND

[0002] Due to the severe energy and environmental problems, energy saving and environmental protection have become a new direction of automobile technology development, and a series of new energy vehicles have been produced. At present, electric vehicles are one of the more potential development directions, but they also face many problems, such as winter range, etc. In terms of range, it mainly depends on the battery capacity and the thermal management technology of the battery.

[0003] Battery thermal management involves heating and cooling of the battery, and there are many forms of battery heating, and there is also a form of heating the battery by liquid through the water-cooled plate. In battery cooling, air cooling, liquid cooling and other forms are often used to cool the lithium battery pack. Since the high energy density and high power density lithium batteries currently used need a suitable working temperature, too high or too low working temperature will have a certain impact on the battery. For the suitable working temperature of lithium battery, the air cooling method cannot meet the heat dissipation demand. The liquid cooling method has the advantages of large specific heat capacity and convective heat transfer coefficient, etc., which can effectively improve the cooling efficiency and ensure the uniformity of the battery module temperature, and one of the main components in the liquid cooling system is the liquid cooling plate / water-cooled plate. Therefore, it is necessary to test the heating and cooling performance of the water-cooled plate.

[0004] For the current mainstream liquid cooling form of the water-cooled plate, the internal flow channel structure is various, and the evaluation of its performance depends on the heat dissipation efficiency, water-side pressure drop and flow resistance. Good heat dissipation capacity and lower flow resistance can reduce the energy consumption of electric vehicles to a certain extent. However, since the test of the heat dissipation capacity needs to install the battery for the whole package test, the whole test cycle time will be longer. SUMMARY

[0005] In order to solve the defects in the prior art, an electric vehicle water-cooled plate performance test bench and a data processing method are provided, and a test scheme conforming to the water-cooled plate performance test is proposed, which can test the heat dissipation performance, water-side pressure drop and flow resistance, and research the control method of the battery thermal management system.

[0006] In order to achieve the purpose of the present application, the electric vehicle water-cooled plate performance test bench provided by the present application comprises two circuits of cooling liquid circuit and refrigerant circuit, including a heat pump air conditioning system, a low-temperature radiator cooling system, a data acquisition and control system and a water-cooled plate test bench,

[0007] The heat pump air conditioning system comprises a compressor, a condensing / evaporating heat sink, a four-way valve, an electronic expansion valve and a plate heat exchanger, the compressor, the condensing / evaporating heat sink, the four-way valve, the electronic expansion valve and the plate heat exchanger are connected to form a refrigerant circuit, and the switching between heating and cooling is realized through the four-way valve, and a controllable cold and hot coolant source is provided for the input of the water-cooled plate test bench;

[0008] The low-temperature radiator cooling system comprises an electric fan, a water-cooled radiator, a three-way valve and a liquid storage tank, the water-cooled radiator, the three-way valve and the liquid storage tank are connected to form a coolant circuit, and the refrigerant circuit exchanges heat with the coolant circuit through the plate heat exchanger, and the low-temperature radiator performance experiment of the water-cooled plate test bench can be realized.

[0009] The water-cooled plate test bench comprises a measured water-cooled plate, a heating element for simulating battery heating and a second temperature sensor for measuring the temperature distribution of the water-cooled plate, wherein the measured water-cooled plate is in communication with the coolant circuit.

[0010] The data acquisition and control system is connected with the heat pump air conditioning system and the low-temperature radiator cooling system.

[0011] Further, a first temperature sensor is arranged in the coolant circuit.

[0012] The switching of the heat pump air conditioning system and the low-temperature radiator cooling system is realized through the three-way valve in the cooling circuit, that is, the switching of the air-cooled / water-cooled cooling system is realized. The heat pump air conditioning system realizes the conversion between refrigeration and heating through the four-way valve, and then heats and cools the coolant through the plate heat exchanger, and the electronic expansion valve controls the temperature of the coolant, thereby providing a controllable cold and hot coolant source for the input of the water-cooled plate test bench. In combination with the sensors in the cooling circuit, the pressure drop (or flow resistance) at different temperatures can be measured, and in combination with the sensors in the test bench, the uniformity of heat distribution on the water-cooled plate can be measured.

[0013] The switching between heating and cooling is realized through the four-way valve, and the cold and hot adjustment of the coolant is realized through the plate heat exchanger, the cold coolant can realize the water-cooled plate heat dissipation performance test, and the hot coolant can realize the water-cooled plate heating distribution uniformity test.

[0014] The water-cooled plate performance test bench adopts a water pump and combines the sensors in the cooling circuit to control the coolant flow at the inlet of the water-cooled plate, thereby the pressure drop (or flow resistance) at different flow rates can be measured.

[0015] Further, the water-cooled plate and the cooling liquid circuit are connected through a quick connector, a water pump is arranged in the cooling liquid circuit, and a temperature sensor and a flow meter are arranged at the quick connector. By controlling the opening degree of the electronic expansion valve, combining the temperature sensor and the flow meter at the quick connector, the temperature of the water inlet of the water-cooled plate can be adjusted, and then the flow of the water pump in the cooling circuit is controlled, so that the test bench can be used to measure the pressure drop or flow resistance under different temperatures and different flows.

[0016] Further, the three-way valve in the cooling liquid circuit can realize switching between low-temperature radiator cooling and direct cooling water cooling, and can be used to measure the pressure drop or flow resistance under different flows. Due to the openness of the test bench, the test bench can also be used to study the control method of the battery thermal management using the air cooling / water cooling hybrid cooling system.

[0017] Further, the data acquisition and control system adopts a data acquisition card and a motion control card, and the LabVIEW software of the upper computer is used to collect sensor data and control related devices in the heat pump system and the low-temperature radiator cooling system. The related devices include fans, compressors, three-way valves, four-way valves, water pumps, temperature sensors, heating elements, and electronic expansion valves. The data acquisition includes fan and compressor power, speed, temperature sensors, flow meters, and pressure sensors on the cooling liquid circuit.

[0018] Further, the water-cooled plate test bench also includes a temperature measurement point arrangement plate, a heating point arrangement plate, and a heat-conducting pad for enhancing heat conduction. The temperature measurement point arrangement plate is provided with at least one second temperature sensor, and the heating point arrangement plate is provided with at least one heating element.

[0019] The temperature sensor and the heating element are used to collect the temperature change curve of each measurement point on the water-cooled plate and to simulate battery heat generation. The heat pump air conditioning system, the low-temperature radiator cooling system, and the data acquisition and control system are combined to complete the water-cooled plate heating temperature uniformity and heat dissipation performance experiment.

[0020] An electric vehicle water-cooled plate performance test data processing method is provided. The method includes flow resistance tests of different cooling liquid flows and water-cooled plate temperature uniformity tests. For the flow resistance tests of different cooling liquid flows, flow meters and pressure sensors are arranged at the water inlet and outlet of the water-cooled plate. When the cooling liquid inlet and outlet flow is stable (within the allowable error range), the corresponding cooling liquid flow and inlet and outlet pressures are collected. The pressure drop under the current corresponding flow can be obtained by calculating the difference between the two values, and the flow resistance change curve of the water-cooled plate under different cooling liquid flows can be drawn. The pressure drop calculation is as follows:

[0021] ΔP=P out -P in

[0022] wherein P out is the cooling liquid pressure at the outlet of the water-cooled plate, P in is the cooling liquid pressure at the outlet of the water-cooled plate;

[0023] For the water-cooled plate temperature uniformity test, temperature uniformity in both the heating and cooling heat dissipation of the water-cooled plate is included:

[0024] 1) When heated, by uniformly arranging a certain number of second temperature sensors on the surface of the water-cooled plate, the temperature change rate of each point is collected and evaluated by using variance (standard deviation). The average temperature T avg of the surface of the water-cooled plate, the surface temperature difference ΔT and the surface standard deviation σ T are calculated as follows:

[0025]

[0026] wherein T i is the temperature measured by the i th temperature sensor, i = 1, 2, … n, T max , T min is the maximum and minimum values of the temperatures measured by the n temperature sensors.

[0027] 2) When cooled and heat-dissipated, in addition to the similar evaluation method when heated, the heat dissipation (heat dissipation Q) of the water-cooled plate also needs to be calculated according to the temperatures of the cooling liquid at the inlet and outlet of the water-cooled plate:

[0028]

[0029] wherein c is the specific heat capacity of the cooling liquid, m is the mass of the cooling liquid in the water-cooled plate, is the temperature of the cooling liquid at the outlet of the water-cooled plate, is the temperature of the cooling liquid at the outlet of the water-cooled plate.

[0030] Further, for the temperature uniformity of the water-cooled plate when heated, the steady-state temperatures of each measurement point can be normalized, and the temperature distribution cloud map of the entire water-cooled plate can be calculated by difference fitting, so that the temperature uniformity of the water-cooled plate can be more intuitively displayed.

[0031] The water-cooled plate performance test bench and data processing method is an open system with high flexibility, and it can also be used to study the control method of the battery thermal management system of an electric vehicle. For example, the control method of the battery thermal management system using a mixed air cooling / water cooling cooling system can be studied, and the number and types of sensors in each circuit can be flexibly arranged according to functional requirements. Through the data acquisition card and the motion control card, the control method of the battery thermal management system of an electric vehicle can be studied by using the LabVIEW software of the upper computer.

[0032] Compared with the prior art, the present application has at least the following beneficial effects:

[0033] 1) The test bench provided by the application belongs to a test test bench independently researched and developed in the related field at home, can test the performance of the water-cooled plate at a lower cost, saves the test time of the battery package, and improves the test efficiency.

[0034] 2) The test bench can simulate the performance of the water-cooled plate on the real electric vehicle. Since the test bench is as close as possible to the actual situation of the real electric vehicle, the test bench system can also be used to study the battery thermal management control method of the electric vehicle, which can further shorten the development time of the battery thermal management control method of the whole vehicle.

[0035] 3) The whole experimental device can be built by using real automobile parts to simulate the actual working condition of the water-cooled plate on the electric vehicle, and the test result has high precision.

[0036] 4) The data acquisition card and the motion control card are used to collect sensor data and control related devices in the test bench in combination with the host computer LabVIEW software, and the whole test bench is flexible and low in cost.

[0037] 5) The water-cooled plate performance test bench and the data processing method are an open system with high flexibility, which can also be used to study the control method of the battery thermal management system of the electric vehicle, such as the control method of the battery thermal management using the air-cooled / water-cooled hybrid cooling system, the number and types of sensors in each circuit are arranged flexibly according to the functional requirements, the development experiment cost of the control method is saved. The data acquisition card and the motion control card are used to study the control method of the battery thermal management system of the electric vehicle in combination with the host computer LabVIEW software. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 It is the overall architecture diagram of the water-cooled plate performance test bench and the data processing method provided by the embodiment of the application.

[0039] Figure 2 It is the principle diagram of the water-cooled plate performance test bench and the data processing method provided by the embodiment of the application.

[0040] Figure 3 It is the sectional view of the water-cooled plate joint and the quick connector connection structure provided by the embodiment of the application.

[0041] Figure 4 It is the overall structure diagram of the water-cooled plate test bench provided by the embodiment of the application.

[0042] Figure 5 It is the principle diagram of the water-cooled plate heating distribution uniformity experiment provided by the embodiment of the application.

[0043] Figure 6 It is one kind of distribution diagram of the temperature measurement point in the water-cooled plate test bench provided by the embodiment of the application.

[0044] Figure 7 is a water-cooled plate heat dissipation performance experiment principle diagram provided by the embodiment of the present application under air conditioning refrigeration.

[0045] Figure 8 is a distribution diagram of a water-cooled plate PTC heater heating point provided by the embodiment of the present application.

[0046] Figure 9 is a water-cooled plate low-temperature radiator cooling performance experiment principle diagram provided by the embodiment of the present application.

[0047] Figure 10 is a temperature contour cloud diagram of a water-cooled plate actual measurement point through interpolation fitting under an environment temperature of-30 DEG C.

[0048] Figure 11 is a temperature contour cloud diagram of a water-cooled plate simulated by a computational fluid dynamics method under an environment temperature of-30 DEG C. DETAILED DESCRIPTION

[0049] The technical solutions of the present application will be further specifically described below by means of specific embodiments and in conjunction with the drawings. It should be understood that the implementation of the present application is not limited to the following embodiments, and any form of modification and / or change of the present application will fall within the scope of protection of the present application.

[0050] As shown in Figure 1 , the present application provides a kind of electric vehicle water-cooled plate performance test platform, including cooling liquid circuit and refrigerant circuit two circuits, including heat pump air conditioning system, low-temperature radiator cooling system, data acquisition and control system, water-cooled plate test bench.The refrigerant circuit of heat pump air conditioning system, low-temperature radiator cooling system is coupled to cooling liquid circuit, cooling liquid circuit is connected with water-cooled plate test bench by quick joint, data acquisition and control system acquisition and control heat pump air conditioning system, low-temperature radiator cooling system, the relevant devices of water-cooled plate test bench.

[0051] As shown in Figure 2 , the refrigerant circuit of heat pump air conditioning system and cooling liquid circuit are connected by plate heat exchanger 102 to realize heat exchange, low-temperature radiator cooling system is coupled in cooling liquid circuit by three-way valve 107, cooling liquid circuit and water-cooled plate test bench 116 are connected by quick joint.Using heat pump air conditioning system to generate cold water and hot water as the input of water-cooled plate test bench 116 cold and hot controllable cooling liquid source.

[0052] As shown in Figure 2As shown, the heat pump air conditioning system includes a compressor 101, a condensing / evaporating heat sink 103, a four-way valve 104, an electronic expansion valve 105, a plate heat exchanger 102, and a liquid storage drying tank (not shown), forming a refrigerant circuit. The condensing / evaporating heat sink 103 is arranged opposite an electric fan. The system realizes switching between heating and cooling through the four-way valve 104, and the refrigeration capacity or heating capacity can be adjusted by adjusting the opening degree of the electronic expansion valve 105. The refrigerant circuit exchanges heat with the cooling liquid circuit through the plate heat exchanger 102, thereby providing a controllable cooling liquid source for the water-cooled plate test bench 116, realizing water-cooled plate heat dissipation performance testing and heating temperature distribution uniformity testing.

[0053] As shown in FIG. 1, the water-cooled plate heat dissipation performance test includes: measuring the pressure drop (i.e., the product of flow resistance and flow rate) at different flow rates and different temperatures, and testing the heat dissipation and heating capacity of the water-cooled plate. Figure 2

[0054] 1) When measuring the pressure difference (flow resistance), the flow rate and the inlet and outlet pressures of the water-cooled plate are collected when the flow rate of the water-cooled plate inlet and outlet is stable (within the allowable error range) through the flow meter and pressure sensor arranged at the inlet and outlet of the water-cooled plate. The pressure drop at the current flow rate can be obtained by calculating the difference between the two values, and the flow resistance variation curve of the water-cooled plate at different cooling liquid flow rates can be drawn. The pressure drop calculation is as follows:

[0055] ΔP = P out -P in

[0056] where P out is the cooling liquid pressure at the outlet of the water-cooled plate, and P in is the cooling liquid pressure at the inlet of the water-cooled plate.

[0057] 2) When measuring the heat dissipation performance of the water-cooled plate, the heat dissipation of the water-cooled plate is calculated by the temperature of the cooling liquid at the inlet and outlet of the water-cooled plate:

[0058]

[0059] where Q is the heat dissipation, c is the specific heat capacity of the cooling liquid, m is the mass of the cooling liquid in the water-cooled plate, is the cooling liquid temperature at the inlet of the water-cooled plate, is the cooling liquid temperature at the outlet of the water-cooled plate. For the temperature uniformity, a certain number of second temperature sensors 130 can be arranged uniformly on the surface of the water-cooled plate to collect the temperature variation rate of each point and evaluate using variance (standard deviation). The average temperature T avg , the surface temperature difference ΔT, and the surface standard deviation σ T are calculated as follows: ​

[0060]

[0061] wherein, T i is the temperature measured by the ith second temperature sensor, i = 1, 2, … n, n is the total number of the second temperature sensors set, T max , T min is the maximum value and the minimum value among the temperatures measured by the n second temperature sensors.

[0062] As shown in Figure 2 , the low-temperature radiator cooling system includes an electric fan 110, a water-cooled radiator 106, a three-way valve 107, a liquid storage tank 108, and a cooling liquid circuit formed thereby. The low-temperature radiator cooling and direct water cooling are switched by the three-way valve 107 in the circuit. The electric fan 110 is arranged opposite to the water-cooled radiator 106. The cooling liquid circuit is connected to the water-cooled plate test bench 116 through a quick connector 119, or uses a joint formed by the cooperation between a soft tube of the same size and a fixing buckle, and the joint form used is not limited to the above form.

[0063] As shown in Figure 3 , the connection between the water-cooled plate connector 117 and the quick connector 119 according to the present application includes the water inlet 125 and the water outlet 126 of the water-cooled plate, or a section of pressure pipe is used to realize the connection between the connector 117 and the water inlet and water outlet of the water-cooled plate, which is not limited to the same type of water inlet and water outlet shown in the figure.

[0064] In some embodiments of the present application, as shown in Figure 3 , the water-cooled plate connector 117 has a groove 118 connected to the quick connector 119 at the interface, and the quick connector 119 includes a self-locking spring 123, a lock sleeve 120, a ball 121, a circlip 122, and a sealing ring (not shown) at the interface of the connector, and the quick connector described herein is not limited to other connector forms, as long as it can meet certain pressure and quick connection requirements.

[0065] As shown in Figure 1 and Figure 2As shown, the data acquisition and control system of the present application adopts a data acquisition card and a motion control card, combines with the LabVIEW software of the host computer, acquires sensor data, and realizes control of related devices of a heat pump air conditioning system, a low-temperature radiator cooling system, etc. The related devices include a fan 110, a compressor 101, a three-way valve 107, a four-way valve 104, a water pump 109, a first temperature sensor 113, a heating element, and an electronic expansion valve 105. The data acquisition information includes the power and rotating speed of the fan 110 and the compressor 101, the temperature information, flow information, and pressure information of the first temperature sensor 113, a flow meter 114, and a pressure sensor 115 on the cooling liquid circuit, and is not limited to the above. Figure 2 The sensor positions marked as shown can be flexibly arranged. In some embodiments of the present application, the heating element is a PTC heater 112. It can be understood that in other embodiments, a gas heating element can be used.

[0066] As shown, Figure 4 The water-cooled plate test bench 116 of the present application includes a measured water-cooled plate 111, a temperature measurement point arrangement plate 128, a heating point arrangement plate 129, a water inlet 125, a water outlet 126, and an upper and lower wrapped thermal insulation layer 127 and a heat-conducting pad (not shown). The water inlet 125 and the water outlet 126 are arranged on the measured water-cooled plate 111, and the heat-conducting pad is arranged between the heating point arrangement plate 129 and the measured water-cooled plate 111, for enhancing the heat-conducting effect between the heating point arrangement plate 129 and the water-cooled plate 111. The overall water-cooled plate test bench 116 uses clamping devices (not shown) to fix the water-cooled plate 111, the temperature measurement point arrangement plate 128, the heating point arrangement plate 129, the upper and lower wrapped thermal insulation layer 127, and the heat-conducting pad, and is not limited to using bolts for clamping. The temperature measurement point arrangement plate 128 is provided with at least one second temperature sensor 130, and the heating point arrangement plate 129 is provided with at least one PTC heater 112. The temperature measurement point arrangement plate 128 and the heating point arrangement plate 129 are flexibly arranged, and are arranged according to the requirements of experimental projects.

[0067] As shown, Figure 5 and Figure 6 As shown, the water-cooled plate heating distribution uniformity experiment is performed on the heat pump air conditioning system working in the heat pump mode. The heat pump air conditioning system exchanges heat with the water-cooled plate test bench 116 through the plate heat exchanger 102, i.e., the plate heat exchanger 102 acts as a condensing radiator, and the condensing / evaporating radiator 103 acts as an evaporating radiator. The high-temperature and high-pressure refrigerant from the compressor 101 heats the cooling liquid in the cooling circuit through the plate heat exchanger 102, and the heated cooling liquid heats the water-cooled plate 111 through the three-way valve 107 and the quick connector 119. In some embodiments of the present application, Figure 6To distribute the second temperature sensor 130 on the temperature measurement point arrangement plate 128, the second temperature sensor 130 measures the temperature distribution of the surface of the water-cooled plate 111, that is, the temperature measurement point arrangement plate 128 should be placed above the water-cooled plate, and the heat-conducting pad is arranged between the two. The steady-state temperature of each measurement point is normalized, and the temperature distribution cloud of the entire water-cooled plate is calculated by the existing interpolation fitting method, which can more intuitively display the temperature uniformity of the water-cooled plate. In other embodiments, the arrangement and number of temperature measurement points are not limited to Figure 6 as shown.

[0068] As shown in Figure 7 and Figure 8 , Figure 7 is the temperature contour cloud of the measured points through interpolation fitting at an environmental temperature of -30°C in an embodiment of the present application, Figure 8 is the temperature contour cloud of the water-cooled plate simulated by the computational fluid dynamics method. Through simulation and experiment comparison, the different temperature distribution regions and proportions have good consistency.

[0069] As shown in Figure 9 and Figure 10 , the water-cooled plate heat dissipation performance experiment under air conditioning refrigeration, the heat pump air conditioning system realizes heat exchange through the plate heat exchanger 102 and the water-cooled plate test bench 116, that is, the plate heat exchanger 102 acts as an evaporative heat sink, and the condensing / evaporative heat sink 103 acts as a condensing heat sink. The low-temperature and low-pressure refrigerant from the expansion valve 105 evaporates through the plate heat exchanger 102, absorbs the heat of the cooling liquid in the cooling circuit, and is refrigerated. The refrigerated cooling liquid passes through the three-way valve 107 and then cools the water-cooled plate 111 through the quick connector 119. The water-cooled plate 111 is provided with a PTC heater 112 to simulate battery heating. In some embodiments of the present application, the arrangement of the heating point of the PTC heater 112 can be arranged according to the battery arrangement, and the arrangement of the point is not limited to Figure 10 as shown. The heating point arrangement plate 129 is placed above the water-cooled plate 111, and a heat-conducting pad is arranged between the two. According to the measurement requirements, the temperature measurement point arrangement plate 128 can be placed above the heating point arrangement plate 129 to simulate the measurement of the surface temperature of the battery, or it can be arranged above the heat-conducting pad, that is, below the heating point arrangement plate 129 to simulate the measurement of the bottom temperature of the battery.

[0070] As shown in Figure 10 and Figure 11As shown, the cooling performance experiment of the water-cooled plate low-temperature radiator is conducted by using a fan 110 in conjunction with the water-cooled radiator 106 to test the heat dissipation of the water-cooled plate 111. Using a pressure sensor 115 and a flow meter 114 located at the quick connector, the pressure drop (or flow resistance) at different flow rates can be measured. The flow rate at the inlet of the water-cooled plate 111 is adjusted by the water pump 109, or the flow rate is controlled by a throttle valve installed in the water pump pipeline. Pressure drop calculations are performed after the flow rate is relatively stable. The temperature at the inlet of the water-cooled plate 111 is adjusted by the opening of the electronic expansion valve 105 in conjunction with the temperature sensor located at the quick connector 119, and the pressure drop (or flow resistance) at different temperatures is measured.

[0071] like Figure 2 , Figure 6 and Figure 10 As shown, due to its open system nature and high flexibility, it can also be used to study control methods for electric vehicle battery thermal management systems. For example, it can be used to study control methods for battery thermal management employing a hybrid air / water cooling system, where the sensor arrangement is not limited to... Figure 2 As shown, the number and types of sensors in each loop can be flexibly arranged according to functional requirements. A control method for the thermal management system of an electric vehicle battery is studied using a data acquisition card and a motion control card, combined with LabVIEW software on a host computer.

[0072] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An electric vehicle water-cooling plate performance test bench, characterized in that: The test bench comprises a cooling liquid circuit and a refrigerant circuit, and specifically comprises a heat pump air conditioning system, a low-temperature radiator cooling system, a data acquisition and control system and a water-cooled plate test bench (116). The heat pump air conditioning system comprises a compressor (101), a condensing / evaporating radiator (103), a four-way valve (104), an electronic expansion valve (105) and a plate heat exchanger (102). The compressor (101), the condensing / evaporating radiator (103), the four-way valve (104), the electronic expansion valve (105) and the plate heat exchanger (102) are connected to form the refrigerant circuit. The four-way valve (104) is used to switch between the refrigeration mode and the heating mode, so that the plate heat exchanger (102) provides a cold source or a heat source for the cooling liquid circuit. The low-temperature radiator cooling system comprises an electric fan (110), a water-cooled radiator (106), a three-way valve (107) and a liquid storage tank (108). The water-cooled radiator (106), the three-way valve (107) and the liquid storage tank (108) are connected to form the cooling liquid circuit. The refrigerant circuit exchanges heat with the cooling liquid circuit through the plate heat exchanger (102). The three-way valve (107) is used to switch the cooling liquid to flow through the water-cooled radiator (106) or to bypass directly. The three-way valve (107) is used to switch between the low-temperature radiator cooling and the direct water cooling. The water-cooled plate test bench (116) comprises a measured water-cooled plate (111), a heating point arrangement plate (129), a temperature measurement point arrangement plate (128) and a heat-conducting pad for enhancing heat conduction. The heating point arrangement plate (129) is provided with at least one heating element for simulating battery heating. The temperature measurement point arrangement plate (128) is provided with at least one second temperature sensor (130) for measuring the temperature distribution of the surface of the water-cooled plate. The inlet (125) and the outlet (126) of the measured water-cooled plate (111) are communicated with the cooling liquid circuit through quick couplings (119). The quick couplings (119), the inlet (125) and the outlet (126) of the measured water-cooled plate (111) are provided with temperature sensors. The inlet (125) and the outlet (126) are also provided with pressure sensors (115). The cooling liquid circuit is also provided with a flow meter (114) and a water pump (109). The data acquisition and control system is connected with the heat pump air conditioning system and the low-temperature radiator cooling system. The data acquisition and control system adopts a data acquisition card and a motion control card, and combines with a host computer LabVIEW software, and is used to acquire data from the temperature sensors, the pressure sensors (115) and the flow meter (114), and is used to control the compressor (101), the four-way valve (104) and the electronic expansion valve (105) in the heat pump air conditioning system, control the electric fan (110), the three-way valve (107) and the water pump (109) in the low-temperature radiator cooling system, and control the heating element on the water-cooled plate test bench (116).By controlling the opening of the electronic expansion valve (105) and the temperature sensor at the water inlet (125), the temperature of the coolant entering the water-cooled plate is adjusted; by controlling the water pump (109), the coolant flow is adjusted; thereby the flow resistance characteristics, heat dissipation performance and temperature distribution uniformity of the water-cooled plate under different temperatures and different flows can be comprehensively determined on one test bench.

2. An electric vehicle water-cooled panel performance test data processing method, characterized in that, The method comprises flow resistance tests for different cooling liquid flow rates and water-cooled plate temperature uniformity tests, wherein for the flow resistance tests for different cooling liquid flow rates, flow meters (114) and pressure sensors (115) are arranged at water-cooled plate water inlets (125) and water outlets (126), when the cooling liquid inlet and outlet flow rates are stable, the corresponding cooling liquid flow rate and inlet and outlet pressures are collected, the pressure drop under the current corresponding flow rate is obtained by calculating the pressure difference, and then a flow resistance change curve of the water-cooled plate under different cooling liquid flow rates is drawn, and the pressure drop is calculated as follows: wherein P is the cooling liquid pressure at the outlet of the water cooling plate, P is the cooling liquid pressure at the outlet of the water cooling plate; for the water cooling plate temperature uniformity test, including the temperature uniformity under the conditions of the water cooling plate being heated and cooled: 1) when heated, by uniformly arranging a certain number of second temperature sensors (130) on the surface of the water cooling plate, collecting the temperature change rate of each point, and using variance or standard deviation for evaluation, the average temperature of the surface of the water cooling plate the surface temperature difference and the surface standard deviation are calculated as follows: ， ， wherein T is the temperature measured by the i-th second temperature sensor, i = 1, 2,... n, , T is the maximum and minimum of the temperatures measured by the n second temperature sensors. 2) During cooling and heat dissipation, in addition to using a similar evaluation method when heated, the heat dissipation amount Q of the water-cooled plate needs to be calculated according to the cooling liquid temperatures at the water-cooled plate inlets and outlets: where c is the specific heat capacity of the coolant, m is the mass of the coolant in the water-cooling plate, Tout is the temperature of the coolant at the outlet of the water-cooling plate, Tout is the temperature of the coolant at the outlet of the water-cooling plate.

3. The performance test data processing method of the water-cooled plate of an electric vehicle according to claim 2, characterized in that: For the temperature uniformity of the water-cooled plate when heated, the steady-state temperatures of each measurement point are normalized, and a temperature distribution cloud map of the entire water-cooled plate is calculated by interpolation fitting, so as to intuitively display the temperature uniformity of the water-cooled plate.

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