A multifunctional oil-cooled stator thermophysical property testing platform and testing method

Abstract

This invention discloses a multifunctional oil-cooled stator thermophysical property testing platform and method, relating to the field of motor thermal management technology. The testing platform includes a control and regulation component and a testing component. The control and regulation component includes a constant-temperature oil bath, a centrifugal pump, a regulating valve, and a mass flow meter arranged along a pipeline. The testing component includes a flow channel test section and pressure and temperature sensors located at both ends of the flow channel test section, which is connected to the pipeline. The flow channel test section includes multiple sub-flow channel test sections, each including a cooling pipe connected to the pipeline and a coil assembly located outside the cooling pipe. Temperature sensors are installed in both the cooling pipe and the coil assembly, and at least one cooling pipe has an internal regulating plate for enhanced heat transfer. This invention can simultaneously and comprehensively measure multiple thermophysical properties and related characteristic parameters, providing data support for the optimized design of cooling pipe structures and significantly improving the heat dissipation performance and operational reliability of motor oil-cooling systems.

Description

Technical Field

[0001] This invention relates to the field of motor thermal management technology, specifically to a multifunctional oil-cooled stator thermal property testing platform and testing method. Background Technology

[0002] With the widespread application of high-power-density motors in electric vehicles, industrial drives, and aerospace, motor thermal management has become a key bottleneck restricting their performance improvement. If losses such as copper and iron losses generated during motor operation are not dissipated in time, the temperature of the windings and core will rise, thereby reducing operating efficiency, weakening output torque, and accelerating the aging and failure of insulation materials. Traditional heat dissipation methods mainly include air cooling and liquid cooling. Among them, oil cooling has been widely studied and applied due to its excellent insulation properties, high specific heat capacity and thermal conductivity, and the ability to achieve a shorter heat dissipation path.

[0003] Currently, existing testing platforms for testing the thermophysical properties and flow characteristics of oil-cooled stator cooling pipes often suffer from problems such as limited functionality, insufficient testing accuracy, and poor adaptability. They cannot simultaneously achieve accurate testing of key parameters such as heat transfer coefficient and pressure drop under various flow channel structures and different operating conditions, making it difficult to meet the testing needs for optimizing cooling pipe structures.

[0004] Therefore, there is an urgent need for a multifunctional, high-precision oil-cooled stator thermophysical property testing platform and corresponding testing methods to address the shortcomings of existing technologies. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose a multifunctional oil-cooled stator thermophysical property testing platform and testing method, solving the technical problem that the existing testing platform cannot simultaneously and comprehensively measure multiple thermophysical properties and related characteristic parameters.

[0006] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a multifunctional oil-cooled stator thermophysical property testing platform. The testing platform includes a control and adjustment component and a testing component. The control and adjustment component includes a constant temperature oil tank, a centrifugal pump, a regulating valve, and a mass flow meter arranged along a pipeline. The testing component includes a flow channel testing section and pressure sensors and temperature sensors located at both ends of the flow channel testing section. The flow channel testing section is connected to the pipeline. The flow channel testing section includes multiple sub-flow channel testing sections. Each sub-flow channel testing section includes a cooling pipe connected to the pipeline and a coil assembly located outside the cooling pipe. The cooling pipe and the coil assembly are respectively equipped with temperature sensors, and at least one cooling pipe has a regulating plate inside for enhancing heat transfer.

[0007] In some embodiments, there are multiple regulating plates, with two regulating plates forming a pair. Multiple pairs of regulating plates are arranged at equal intervals along the extension direction of the cooling pipe, and the spacing between each pair of regulating plates gradually increases along the flow direction of the cooling pipe.

[0008] In some embodiments, the cooling conduit includes a top plate and a bottom plate that overlap each other, with the bottom plate integrally formed with the regulating plate.

[0009] In some embodiments, the coil assembly includes two heating coils and an insulating layer enclosing the heating coils, with the two heating coils respectively arranged on both sides of a cooling pipe.

[0010] In some embodiments, temperature sensors are provided on the top and bottom walls of the cooling pipe; temperature sensors are also provided on the top and bottom walls of the insulating layer.

[0011] In some embodiments, each sub-flow channel test section further includes flow meters, valves, and pressure gauges arranged along the pipeline.

[0012] In some embodiments, the sub-flow channel test section includes a first sub-flow channel test section, a second sub-flow channel test section, and a third sub-flow channel test section; wherein, the cooling pipe of the first sub-flow channel test section has a smooth pipe wall, and the cooling pipe of the second sub-flow channel test section is provided with an adjusting plate.

[0013] In some embodiments, the two ends of the sub-channel test section are connected to the pipeline via flanges.

[0014] In some embodiments, the control and regulation assembly further includes an exhaust valve and a filter arranged along the pipeline, the exhaust valve being used to discharge gas from the pipeline and the filter being used to purify the oil passages of the pipeline.

[0015] Secondly, the present invention also provides a multifunctional oil-cooled stator thermophysical property testing method, applied to the aforementioned testing platform. The testing method includes: adjusting and stabilizing the oil temperature of the constant-temperature oil bath based on test setting conditions; adjusting the regulating valve and stabilizing the flow rate of the pipeline based on test setting conditions; obtaining the temperature of the cooling pipeline and the inlet and outlet pressures; and calculating the local convective heat transfer coefficient of the flow channel wall and the local pressure drop of the flow channel based on the obtained temperature, pressure, and flow rate.

[0016] Compared with existing technologies, the multifunctional oil-cooled stator thermophysical property testing platform provided by this invention can achieve precise control of cooling oil temperature and flow rate, as well as synchronous acquisition of key data such as temperature and pressure, through control and adjustment components and testing components. It can simultaneously acquire the local wall temperature distribution and local pressure drop of the flow channel, overcoming the limitation of traditional devices that can only measure macroscopic average values ​​and solving the problem of single-function testing platforms. Simultaneously, multiple sub-flow channel test sections are set up, and adjustment plates are configured in some cooling pipes, enabling simultaneous comparative testing of cooling pipes with different structures, meeting diverse testing needs and improving the platform's versatility. The rational layout of each component, stable boundary conditions, and high-precision experimental data can provide calibration benchmarks for CFD simulation, shortening the structural optimization cycle and improving design efficiency. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the framework of the multifunctional oil-cooled stator thermophysical property testing platform provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the test component provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the flow channel test section provided in an embodiment of the present invention; Figure 4 yes Figure 3 Sectional view of section AA; Figure 5 This is a schematic diagram of the cooling pipe structure provided in an embodiment of the present invention; Figure 6 This is a flowchart illustrating the testing method provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the structure of the motor provided in an embodiment of the present invention.

[0018] Explanation of reference numerals in the attached figures: 100. Testing platform; 110. Control and regulating components; 111. Thermostatic oil bath; 112. Exhaust valve; 113. Centrifugal pump; 114. Filter; 115. Regulating valve; 116. Mass flow meter; 120. Test assembly; 121. First temperature sensor; 122. First pressure sensor; 123. Second temperature sensor; 124. Second pressure sensor; 125. Flow channel test section; 125A. First sub-flow channel test section; 125B. Second sub-flow channel test section; 125C. Third sub-flow channel test section; 1251. Flow meter; 1252. Valve; 1253. Pressure gauge; 1254. Cooling pipe; 12541. Top plate; 12542. Bottom plate; 12543. Adjusting plate; 1255. Coil assembly; 12551. Heating coil; 12552. Insulation layer; 200. Test methods; 300, motor; 310, motor coil; 320, stator core. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0020] With the widespread application of high-power-density motors in electric vehicles, industrial drives, and aerospace, motor thermal management has become a key bottleneck restricting their performance improvement. Currently, existing testing platforms for testing the thermophysical properties and flow characteristics of oil-cooled stator cooling pipes often suffer from problems such as limited functionality, insufficient testing accuracy, and poor adaptability.

[0021] To address the technical problem that testing platforms cannot simultaneously and comprehensively measure multiple types of thermal properties and related characteristic parameters, this invention provides a multifunctional oil-cooled stator thermal property testing platform. This testing platform can simultaneously and comprehensively measure multiple types of thermal properties and related characteristic parameters, providing data support for the optimized design of cooling pipe structures and significantly improving the heat dissipation performance and operational reliability of motor oil-cooling systems.

[0022] It should be noted that the test platform provided by this invention is used for, but not limited to, oil-cooled stator thermal property testing. For ease of explanation, this invention will only use the application of the test platform to oil-cooled stator thermal property testing as an example. The principle of the test platform applied to other types of equipment is essentially the same as that applied to oil-cooled stator thermal property testing, and will not be elaborated here.

[0023] This invention provides a multifunctional oil-cooled stator thermophysical property testing platform 100, such as... Figure 1 and Figure 2 As shown, the test platform 100 includes a control and adjustment component 110 and a test component 120. The control and adjustment component 110 includes a constant temperature oil tank 111, a centrifugal pump 113, a regulating valve 115, and a mass flow meter 116 arranged along the pipeline. The test component 120 includes a flow channel test section 125 and pressure sensors and temperature sensors located at both ends of the flow channel test section. The flow channel test section is connected to the pipeline. The flow channel test section includes multiple sub-flow channel test sections. Each sub-flow channel test section includes a cooling pipe 1254 connected to the pipeline and a coil assembly 1255 located outside the cooling pipe. The cooling pipe 1254 and the coil assembly 1255 are respectively equipped with temperature sensors. At least one cooling pipe 1254 has an adjustment plate 12543 inside for enhancing heat exchange.

[0024] The control and regulation component 110 is a component used to control and regulate parameters such as the temperature and flow rate of the cooling oil.

[0025] For example, the control and regulation assembly 110 includes a constant temperature oil tank 111, an exhaust valve 112, a centrifugal pump 113, a filter 114, a regulating valve 115, and a mass flow meter 116 arranged sequentially along the pipeline.

[0026] The constant temperature oil bath 111 serves as a cooling oil storage container, providing temperature-controlled cooling oil and acting as a system cold source to ensure that the cooling oil inlet temperature meets the set requirements during the test, thus guaranteeing the accuracy of the test.

[0027] The exhaust valve 112 serves as a pipeline venting device. After the cooling oil flows out of the constant temperature oil tank 111, the air in the pipeline is discharged through the exhaust valve 112, which avoids air bubbles interfering with the stability of the cooling oil flow and the accuracy of test data. At the same time, it protects the centrifugal pump 113 and extends the service life of the equipment.

[0028] Centrifugal pump 113 is the system power unit. After passing through exhaust valve 112, the cooling oil is driven by centrifugal pump 113 to achieve circulation in the pipeline and flow channel test section, ensuring that the cooling oil flows stably through each test area.

[0029] As a pipeline purification device, filter 114 can filter out impurities and particulate matter in the cooling oil, prevent pipeline blockage, ensure smooth flow and normal operation of test components, reduce the interference of impurities on test results, and improve test accuracy.

[0030] The regulating valve 115 is used to regulate the flow rate of cooling oil in the pipeline. It works with the mass flow meter to achieve precise control and stable flow rate maintenance, and can adapt to the flow rate requirements of different test conditions. The regulating valve 115 and the centrifugal pump 113 work together to form a flow regulation unit to achieve high-precision stepless regulation of cooling oil flow rate.

[0031] The mass flow meter 116 is used to monitor the flow rate of cooling oil in the pipeline in real time, realize the accurate acquisition of flow data, and provide a reliable flow basis for subsequent calculation of parameters such as heat transfer coefficient and pressure drop.

[0032] The test assembly 120 includes a flow channel test section 125, with pressure sensors and temperature sensors located at both ends of the flow channel test section 125. For example... Figure 2 As shown, exemplarily, a first temperature sensor 121 and a first pressure sensor 122 are provided at the inlet of the flow channel test section 125; a second temperature sensor 123 and a second pressure sensor 124 are provided at the outlet of the flow channel test section 125. The flow channel test section 125 is connected to a pipeline to ensure that the cooling oil can flow smoothly into the flow channel test section for testing. During the test, the first temperature sensor 121 and the second temperature sensor 123 are used to collect the cooling oil temperature at the inlet and outlet of the flow channel test section 125, and the first pressure sensor 122 and the second pressure sensor 124 are used to collect the pressure at the inlet and outlet of the flow channel test section 125.

[0033] The flow channel test section 125 includes multiple sub-flow channel test sections. The number of sub-flow channel test sections can be determined according to actual needs, such as 2, 3, 4, etc.

[0034] For example, such as Figure 3 As shown, each sub-flow channel test section also includes a flow meter 1251, a valve 1252, and a pressure gauge 1253 arranged along the pipeline. The flow meter 1251 is used to monitor the flow rate of the cooling oil in the corresponding sub-flow channel test section in real time, forming a dual monitoring system with the mass flow meter 116 in the control and regulation assembly 110 to improve the accuracy of the flow data; the valve 1252 is used to control the on / off state of the corresponding sub-flow channel test section, and can open or close a specific sub-flow channel test section according to the test requirements, realizing the function of testing a single channel or multiple channels simultaneously, improving the flexibility of the test platform; the pressure gauge 1253 is used to monitor the pressure in the sub-flow channel test section in real time, and works with the pressure sensors at both ends of the channel test section to comprehensively obtain the pressure distribution in the sub-flow channel, providing more comprehensive pressure data for the calculation of local pressure drop.

[0035] Each sub-channel test section includes a cooling pipe 1254 connected to the main pipe and a coil assembly 1255 located outside the cooling pipe 1254. The cooling pipe 1254, connected to the main pipe, simulates the cooling flow path of the motor stator. Cooling oil flows within the cooling pipe 1254 and exchanges heat with the pipe wall; for example, the cooling pipe 1254 is made of stainless steel. The coil assembly 1255, located outside the cooling pipe 1254, simulates the heating state of the motor stator coil, providing a stable heat flux density for testing. The coil assembly 1255 has the same coil structure as the actual motor coil. Temperature sensors are installed on both the cooling pipe 1254 and the coil assembly 1255 to collect the wall temperature of the cooling pipe 1254 and the temperature of the coil assembly 1255 in real time, providing temperature data for the inversion of the convective heat transfer coefficient. At least one cooling pipe 1254 has an adjustment plate inside to enhance heat transfer. By setting the adjustment plate, different heat transfer structures of the cooling pipe can be simulated, expanding the functional range of the test platform.

[0036] For example, such as Figure 4As shown, the coil assembly 1255 includes a heating coil 12551 and an insulating layer 12552 wrapped around the heating coil. Two heating coils 12551 are respectively arranged on both sides of the cooling pipe 1254, and are symmetrically arranged relative to the cooling pipe 1254. Temperature sensors are installed on the top and bottom walls of the insulating layer 12552 to collect the temperature of the heating coils 12551. The heating coils 12551 use resistance heating, and the heating power can be adjusted by an external voltage regulating module to achieve precise control of heat flux density, simulating the heating state of the motor stator coil under different loads. The insulating layer 12552 is made of high-temperature resistant and high-insulation materials, such as ceramics and high-temperature silicone, to isolate the heating coils from the cooling pipe, prevent leakage accidents, reduce heat loss to the outside, and ensure that the heat generated by the heating coils can be efficiently transferred to the cooling pipe, improving testing efficiency and accuracy.

[0037] For example, such as Figure 5 As shown, temperature sensors are installed on the top and bottom walls of the cooling pipe 1254 to collect the temperature of the pipe walls. The cooling pipe 1254 is formed by a top plate 12541 and a bottom plate 12542 overlapping each other, and an regulating plate 12543 for enhancing heat transfer is installed inside. The arrangement of the regulating plate 12543 can be flexibly set according to actual needs, and it adopts an integral molding structure with the bottom plate 12542. For example, the regulating plate 12543 can be integrally formed by selective laser melting (SLM) technology to achieve high-precision fabrication of complex internal structures.

[0038] In some embodiments, such as Figure 5 As shown, there are multiple regulating plates 12543. Two regulating plates 12543 form a pair. Multiple pairs of regulating plates 12543 are arranged at equal intervals along the extension direction of the cooling pipe 1254. The spacing between each pair of regulating plates 12543 gradually increases along the flow direction of the cooling pipe 1254.

[0039] In this embodiment, the regulating plates 12543 are arranged symmetrically, with each pair of regulating plates 12543 symmetrically positioned relative to the central axis of the cooling pipe 1254. This ensures uniform force on the cooling oil as it flows within the pipe, preventing localized flow velocity anomalies from affecting test results. Multiple pairs of regulating plates 12543 are arranged at equal intervals along the length of the cooling pipe 1254, ensuring the uniformity of the heat transfer enhancement effect. Under low cooling oil flow conditions, this arrangement of regulating plates 12543 enhances the heat transfer coefficient compared to a smooth pipe without a smooth surface, thereby improving the motor's heat transfer performance. The regulating plates 12543 can be made of metal, such as copper or aluminum, to further enhance the heat transfer effect.

[0040] In some embodiments, such as Figure 2As shown, the flow channel test section 125 includes three sub-flow channel test sections, namely the first sub-flow channel test section 125A, the second sub-flow channel test section 125B, and the third sub-flow channel test section 125C. Among them, the cooling pipe of the first sub-flow channel test section 125A has a smooth pipe wall, and the cooling pipe of the second sub-flow channel test section 125B is equipped with an adjusting plate 12543.

[0041] In this embodiment, the cooling pipe of the first sub-flow channel test section 125A has a smooth wall and is not equipped with any adjusting plates. It serves as a benchmark test section to obtain parameters such as the heat transfer coefficient and pressure drop of the smooth-walled cooling pipe. The cooling pipe of the second sub-flow channel test section 125B is equipped with adjusting plates 12543. It serves as a heat transfer enhancement test section to obtain relevant performance parameters of the cooling pipe with the heat transfer enhancement structure. The third sub-flow channel test section 125C can be configured with a different structure than the first and second sub-flow channel test sections (such as adjusting plates of different sizes or shapes) according to testing requirements, further expanding the testing range. The three sub-flow channel test sections can operate independently or simultaneously, enabling comparative testing of cooling pipes with different structures and further improving the platform's versatility and practicality.

[0042] In some embodiments, such as Figure 3 As shown, the two ends of the sub-channel test section are connected to the pipeline via flanges.

[0043] In this embodiment, both ends of each sub-channel test section are connected to the pipeline via flanges. The flange connections are sealed with gaskets to ensure airtightness and prevent cooling oil leakage. Flange connections offer advantages such as easy disassembly, secure connection, and good sealing performance, facilitating the installation, disassembly, and replacement of the sub-channel test sections. When testing sub-channel test sections with different structures, the original test section can be quickly disassembled and a new test section installed, improving the flexibility and maintainability of the testing platform. Simultaneously, the robustness of the flange connections ensures that the sub-channel test section and the pipeline will not loosen during testing, guaranteeing stable cooling oil flow and improving the accuracy of test data.

[0044] This invention also provides a multifunctional oil-cooled stator thermophysical property testing method 200, applied to the aforementioned testing platform 100, such as... Figure 6 As shown, the test method 200 includes: Step S210: Based on the test settings, adjust and stabilize the oil temperature of the constant temperature oil bath.

[0045] Specifically, based on the testing requirements, the target oil temperature of the constant temperature oil bath is set, the constant temperature oil bath is started, and the oil temperature is adjusted through its internal heating and cooling devices. After the oil temperature stabilizes at the set value, the constant temperature oil bath is kept running to ensure that the inlet temperature of the cooling oil is stable, laying the temperature foundation for subsequent tests.

[0046] Step S220: Based on the test settings, adjust the regulating valve and stabilize the flow rate in the pipeline.

[0047] Specifically, according to the test conditions, the flow rate of cooling oil in the pipeline is adjusted by regulating the regulating valve, while observing the real-time reading of the mass flow meter. The opening of the regulating valve is gradually adjusted until the flow rate reaches the set value. Then, the opening of the regulating valve is kept constant to ensure the flow rate in the pipeline is stable, providing a stable flow condition for heat exchange and pressure drop tests.

[0048] Step S230: Obtain the temperature of the cooling pipe and the inlet and outlet pressures.

[0049] Specifically, after the oil temperature and flow rate stabilize, the simulated coil heating is started (the uniform heat flux density is set through the pressure regulating module). After the system reaches thermal equilibrium, the temperature distribution data of the pipe wall is collected by the temperature sensor on the cooling pipe, and the inlet and outlet pressure data are collected by the pressure sensors at both ends of the flow channel test section. At the same time, the real-time flow data of the mass flow meter is recorded. All data are collected and stored synchronously to ensure the integrity and synchronization of the data.

[0050] Step S240: Calculate the local convective heat transfer coefficient of the flow channel wall and the local pressure drop of the flow channel based on the obtained temperature, pressure and flow rate.

[0051] Specifically, based on the collected heat flux density, cooling oil flow rate, inlet oil temperature, and cooling pipe wall temperature, the local convective heat transfer coefficient of the flow channel wall is obtained by inversion according to Newton's law of cooling and related heat transfer formulas; based on the total pressure drop measured by the differential pressure gauge and the preset local resistance model, combined with the linear regression method, the local pressure drop of the flow channel is calculated to complete the test process.

[0052] To facilitate understanding, the overall solution for the testing platform will be summarized and explained first: Overall system design: Construct a closed-loop oil circulation circuit, integrating components such as a constant temperature oil tank, centrifugal pump, filter, regulating valve, exhaust valve and heating plate to achieve high-precision digital control of inlet oil temperature, flow rate and heat load.

[0053] The flow channel test section is prepared by using selective laser melting (SLM) metal 3D printing technology to integrally form a cooling flow channel with internal staggered baffles (adjustment plates), balancing structural complexity and manufacturing precision. The two ends of the flow channel are welded with disc-type clamps by argon arc welding, which provides reliable sealing while providing definite local resistance characteristics.

[0054] Multi-point temperature measurement: Temperature sensors are arranged on the upper and lower walls of the heating coil and the upper and lower walls of the cooling pipe to realize real-time acquisition of local wall temperature; and temperature sensors are arranged inside the cooling pipe to obtain the local temperature of the fluid.

[0055] Differential pressure measurement: Differential pressure gauges are installed at the inlet and outlet of the flow channel to measure the total pressure drop, and the local resistance and friction resistance components are obtained by linear regression.

[0056] Collaborative control and data processing: The control system performs closed-loop regulation of oil temperature, flow rate, and heating power; the collected temperature and pressure difference data are input into the calculation module, and the local convective heat transfer coefficient is obtained by inversion based on Newton's law of cooling and heat transfer formula; the local pressure drop is calculated by linear regression combined with the pressure difference model and experimental data.

[0057] Experimental simulation closed loop: The local heat transfer coefficient and pressure drop data obtained from the experiment are used for the verification and calibration of the numerical simulation model, supporting the iterative design of structural optimization.

[0058] The flow channel test section 125 includes a first sub-flow channel test section 125A, a second sub-flow channel test section 125B, and a third sub-flow channel test section 125C. The cooling pipe of the first sub-flow channel test section 125A has a smooth wall, and the cooling pipe of the second sub-flow channel test section 125B is equipped with an adjusting plate 12543. These examples will be used for the derivation and explanation.

[0059] Example 1: The second sub-flow channel test section 125B and the third sub-flow channel test section 125C are closed by valve 1252. The cooling pipe of the first sub-flow channel test section 125A has a smooth pipe wall and is adjusted to a low flow rate. The flow rate is measured by flow meter 1251, pressure gauge 1253 and first pressure sensor 122.

[0060] (1) Under laminar flow conditions: (2) (3) In the formula It is the pressure difference; This is the drag coefficient; The length of the flow channel; The hydraulic diameter of the flow channel; The density of the oil; For flow rate; It is the Reynolds number; This refers to the viscosity of the oil.

[0061] The final complete inversion formula is: (4) By directly substituting the experimental data into this final formula, the oil viscosity can be calculated. .

[0062] Example 2: The first sub-flow channel test section 125A and the third sub-flow channel test section 125C are closed by valve 1252, and the second sub-flow channel test section 125B is tested. The oil cooling channel in the second sub-flow channel test section 125B is the enhanced heat exchange wall to be evaluated.

[0063] Heating coils are used to test the temperature rise of different wall structures using temperature sensors. The heat transfer performance of different structures can be compared using the following formula for calculating the local heat transfer coefficient.

[0064] Core definition (derived directly from Newton's law of cooling): (5) Formula for calculating local fluid temperature: (6) Total heating amount from the inlet to point x (assuming uniform heating conditions): (7) In the formula The coefficient of heat transfer is the local convective heat transfer coefficient. The wall heat flux density; Let x be the wall temperature at position x; Let x be the local temperature of the fluid at position x; The fluid inlet temperature; fluid mass flow rate The specific heat capacity at constant pressure of the fluid; Let x be the total heat absorbed by the fluid from the inlet to point x. Let x be the total heat exchange area from the inlet to point x.

[0065] Substituting equations (6) and (7) into equation (5), assuming uniform heating, the final complete inversion formula is: (8) By directly substituting the experimental data into this final formula, the result can be calculated. .

[0066] In some embodiments, voltage drop and coil temperature rise can be measured simultaneously.

[0067] For example, the first sub-flow channel test section 125A, the second sub-flow channel test section 125B, and the third sub-flow channel test section 125C can be opened and closed by valve 1252 to measure the branch flow distribution.

[0068] For example, such as Figure 7As shown, the motor 300 includes a motor coil 310 and a stator core 320. The coil assembly 1255 of the test platform 100 adopts the same structure as the actual motor coil to improve test accuracy. A flow channel is provided between the two rows of the motor coil 310 and is fixed by the teeth of the stator core 320; correspondingly, a cooling pipe 1254 is provided between the two rows of the coil assembly 1255.

[0069] The various embodiments described above can be arbitrarily combined without interfering with each other, and the combined embodiments also possess the advantages of the independent embodiments. To more clearly demonstrate the technical advantages of this application, the overall beneficial effects are summarized as follows: This testing platform boasts a high degree of integration and comprehensive testing functions. By integrating control and testing components, it can precisely regulate cooling oil temperature and flow rate, simultaneously collect parameters such as temperature and pressure, and obtain local wall temperature and pressure drop in the flow channel. This solves the problem of traditional platforms having limited functionality and only being able to measure macroscopic average values. The testing section can invert the local convective heat transfer coefficient based on heat transfer formulas, compare the heat transfer effects of different flow channel structures through replaceable interfaces, calculate local pressure drop and oil viscosity by combining pressure difference data, and measure the correlation between heat generation and coil temperature rise.

[0070] The platform boasts high testing accuracy and reliable data. Its optimized layout and piping ensure stable oil flow, while precisely positioned sensors effectively reduce calculation errors, providing a reliable basis for parameter analysis and structural optimization. Furthermore, it is highly versatile, employing multiple test sections and a modular design to conduct comparative tests on different structures. It also facilitates the replacement of cooling media and structural reinforcement, and is easy to maintain.

[0071] In addition, the platform's experimental data can provide accurate calibration for CFD simulation, shorten the structural optimization cycle, quantify the heat transfer and flow resistance characteristics of different reinforced structures, provide data support for engineering design, and effectively improve the heat dissipation efficiency and reliability of high power density motor oil cooling systems.

[0072] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A multifunctional oil-cooled stator thermophysical property testing platform, characterized in that, include: Control and regulation components include a thermostatic oil bath, a centrifugal pump, regulating valves, and a mass flow meter arranged along the pipeline; The test assembly includes a flow channel test section and pressure and temperature sensors located at both ends of the flow channel test section, wherein the flow channel test section is connected to the pipeline; The flow channel test section includes multiple sub-flow channel test sections, each of which includes a cooling pipe connected to the main pipe and a coil assembly located outside the cooling pipe; the cooling pipe and the coil assembly are respectively equipped with temperature sensors, and at least one of the cooling pipes is equipped with a regulating plate for enhancing heat exchange.

2. The testing platform according to claim 1, characterized in that, The number of regulating plates is multiple, with two regulating plates forming a pair. The multiple pairs of regulating plates are arranged at equal intervals along the extension direction of the cooling pipe, and the spacing between each pair of regulating plates gradually increases along the flow direction of the cooling pipe.

3. The testing platform according to claim 2, characterized in that, The cooling pipe includes a top plate and a bottom plate that overlap each other, and the bottom plate is integrally formed with the adjusting plate.

4. The testing platform according to claim 1, characterized in that, The coil assembly includes two heating coils and an insulating layer surrounding the heating coils, with the two heating coils respectively arranged on both sides of the cooling pipe.

5. The testing platform according to claim 4, characterized in that, The temperature sensor is provided on the top and bottom walls of the cooling pipe; the temperature sensor is provided on the top and bottom walls of the insulating layer.

6. The testing platform according to claim 1, characterized in that, Each of the sub-flow channel test sections also includes flow meters, valves, and pressure gauges arranged along the pipeline.

7. The testing platform according to claim 6, characterized in that, The sub-flow channel test section includes a first sub-flow channel test section, a second sub-flow channel test section, and a third sub-flow channel test section; wherein, the cooling pipe of the first sub-flow channel test section has a smooth pipe wall, and the cooling pipe of the second sub-flow channel test section is provided with the adjusting plate.

8. The testing platform according to claim 1, characterized in that, The two ends of the sub-channel test section are connected to the pipeline via flanges.

9. The testing platform according to claim 1, characterized in that, The control and regulation assembly also includes an exhaust valve and a filter arranged along the pipeline, the exhaust valve being used to discharge gas from the pipeline and the filter being used to purify the oil passages of the pipeline.

10. A multifunctional oil-cooled stator thermophysical property testing method, applied to the testing platform described in any one of claims 1-9, characterized in that, The testing method includes: Based on the test settings, the oil temperature of the constant temperature oil bath is adjusted and stabilized. Based on the test settings, the regulating valve is adjusted to stabilize the flow rate in the pipeline; The temperature of the cooling pipe and the inlet and outlet pressures are obtained; The local convective heat transfer coefficient of the flow channel wall and the local pressure drop of the flow channel are calculated based on the obtained temperature, pressure and flow rate.

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