Method for observing motion characteristics of internal flow field of stator cooling system of oil-cooled motor

Abstract

The invention provides an oil-cooled motor stator cooling system internal flow field motion characteristic observation method, which can simulate a real motor internal cooling flow circulation process and realize visual observation and analysis by building an experiment platform comprising a full-transparent motor experiment device. The effect of dynamically capturing the flow field can be greatly improved by utilizing tracer particles and corresponding filters on the laser; image processing is executed through a PIV technology, and a local part of a flow channel in the motor is enhanced by adopting a mask, so that the efficiency and precision of flow field data extraction and calculation can be improved; according to the obtained various parameters such as flow field vorticity, turbulence intensity distribution, streamline characteristics and turbulent kinetic energy, accurate characterization of complex flow characteristics and heat dissipation characteristics of the cooling fluid can be finally realized, and the method has important guiding significance for design and optimization of a motor cooling system.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of new energy vehicle electric drive motor, and particularly relates to an internal flow field motion characteristic observation method of an oil-cooled motor stator cooling system. BACKGROUND

[0002] Due to the complex and changeable working conditions faced by the high-speed oil-cooled motor applied in new energy vehicles, how to design the oil cooling system is still one of the technical problems in the field at the present stage. The cooling oil circulation path in the motor oil cooling system is relatively complex, and its flow characteristics and heat dissipation characteristics are easily affected by various factors such as the internal structure of the motor, and it is difficult to intuitively and accurately observe and analyze. Individual prior art such as the applicant's previous Chinese patent CN119290323A provides a visual experiment platform capable of simulating the internal flow of the oil-cooled motor stator and the oil injection ring flow channel, but it is not perfect enough for specific flow characteristics and corresponding heat dissipation characteristic analysis, and lacks accurate acquisition and analysis means for vorticity field, turbulent intensity distribution and related heat dissipation rules. SUMMARY

[0003] Therefore, in view of the technical problems existing in the field, the application provides an internal flow field motion characteristic observation method of an oil-cooled motor stator cooling system, which specifically comprises the following steps:

[0004] Step one, build a motor stator cooling system experiment platform, including a fully transparent motor experiment device, fluid measurement elements, fluid conveying pipelines, a power pump, an oil tank, a high-speed camera, a laser, and a support frame; wherein the motor experiment device is composed of a machine shell and a stator, a rotor, a winding, a cooling component and a corresponding flow channel arranged according to the internal structure of a real motor; a cooling fluid inlet is arranged on the transparent machine shell and is communicated with the fluid conveying pipeline, and a cooling fluid outlet is communicated with the oil tank, which can realize the circulation of the cooling fluid under the action of the power pump; the high-speed camera is used to shoot the cooling fluid image in the motor cooling flow channel, and the laser is used to form a uniform area light to illuminate the cooling flow channel; the high-speed camera and the laser are arranged in a mutually orthogonal manner; the fluid measurement elements are installed on the fluid conveying pipeline to measure the parameters of the cooling fluid including flow, temperature, pressure, etc.

[0005] Step two, complete the related preparation work of the experiment observation, including: adding tracer particles with a specific concentration in the cooling fluid, and installing a corresponding filter on the high-speed camera to improve the clarity of the tracer particles in the image; adjust the field of view of the high-speed camera and the light field of the laser;

[0006] Step three, start the power pump to form a cooling fluid circulation in the oil tank, fluid conveying pipeline and motor experiment device and start the experiment, and simultaneously collect continuous images of the cooling fluid in the cooling flow channel through the high-speed camera;

[0007] Step four, the collected images are processed using particle image velocimetry (PIV) to calculate the corresponding velocity field and vorticity field and other flow field data;

[0008] Step five, based on the obtained flow field data, the vorticity, turbulence intensity distribution, and flow parameters including flow line characteristics and turbulent kinetic energy are calculated, and the fluid flow state in the cooling channel is fully characterized and analyzed.

[0009] Further, a pair of oil injection rings are used in the motor experimental device, which are installed on both sides of the stator.

[0010] Further, the fluid measuring element is specifically selected from a flowmeter, a thermocouple, and a pressure gauge.

[0011] Further, in step four, the collected images are also processed by a mask to improve the efficiency and accuracy of flow field data extraction and calculation.

[0012] The above-mentioned oil-cooled motor stator cooling system internal flow field motion characteristic observation method provided by the present application can simulate the real motor internal cooling flow circulation process and realize visual observation and analysis by building an experimental platform including a fully transparent motor experimental device. The use of tracer particles and corresponding filters on the laser can greatly improve the effect of dynamic capture of the flow field. The PIV technology is used for image processing, and the mask is used to enhance the local flow channel inside the motor, which can improve the efficiency and accuracy of flow field data extraction and calculation. According to the obtained flow field vorticity, turbulence intensity distribution, flow line characteristics, and turbulent kinetic energy, the complex flow characteristics and heat dissipation characteristics of the cooling fluid can be accurately characterized, which has important guiding significance for the design and optimization of the motor cooling system. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 The optional structure diagram of the motor stator cooling system experimental platform built in the method provided by the present application. DETAILED DESCRIPTION

[0014] The technical solutions of the present application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0015] The oil-cooled motor stator cooling system internal flow field motion characteristic observation method provided by the present application specifically includes the following steps:

[0016] Step one, build aFigure 1 The motor stator cooling system experimental platform shown includes a full transparent motor experimental device 5, fluid measuring elements 6, fluid delivery pipelines 7, a power pump 8, an oil tank 3, a high-speed camera 1, a laser 10, and a support frame 4; wherein the motor experimental device 5 is composed of a casing and a stator, a rotor, windings, cooling components, and corresponding flow channels arranged according to the internal structure of a real motor; a cooling fluid inlet is arranged on the transparent casing and is in communication with the fluid delivery pipelines 7, and a cooling fluid outlet is in communication with the oil tank 3, and under the action of the power pump 8, the circulation of the cooling fluid can be realized; the high-speed camera 1 is used to shoot the images of the cooling fluid in the cooling flow channel, and the laser 10 is used to form a uniform surface light to illuminate the cooling flow channel; the high-speed camera 1 and the laser 10 are arranged in a mutually orthogonal manner; the fluid measuring elements 6 are installed on the fluid delivery pipelines 7 and are used to measure the parameters of the cooling fluid including flow rate, temperature, and pressure;

[0017] Step two, complete the relevant preparation work of experimental observation, including: adding tracer particles of a specific concentration in the cooling fluid, and installing corresponding filter sheets 2 for improving the clarity of the tracer particles in the images on the high-speed camera 1; adjusting the support frame 4 and the laser support frame 9 to make the field of view of the high-speed camera and the light field of the laser meet the experimental requirements;

[0018] Step three, start the power pump 8 to form the circulation of the cooling fluid in the oil tank 3, the fluid delivery pipelines 7, and the motor experimental device 1 and begin the experiment, and at the same time, continuously shoot the images of the cooling fluid in the cooling flow channel through the high-speed camera;

[0019] Step four, process the collected images by using the particle image velocimetry technology to calculate the corresponding velocity field and vorticity field and other flow field data;

[0020] Step five, calculate the vorticity and the distribution of the turbulent intensity based on the obtained flow field data, and extract the flow parameters including the streamline characteristics and the turbulent kinetic energy, and on this basis, realize the comprehensive characterization and analysis of the fluid flow state in the cooling flow channel.

[0021] In a preferred embodiment of the present application, a pair of oil injection rings are used in the motor experimental device and are respectively installed in the double-side spray cooling structure at both ends of the stator.

[0022] In a preferred embodiment of the present application, the fluid measuring elements are specifically selected as a flowmeter, a thermocouple, and a pressure gauge.

[0023] In a preferred embodiment of the present application, in step four, the collected images are also processed locally in the motor internal flow channel through a mask to improve the efficiency and accuracy of the extraction and calculation of the flow field data.

[0024] It should be understood that the size of the serial number of each step in the embodiments of the present application does not mean the order of execution, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0025] Although embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and alterations can be made thereto without departing from the principles and spirit of the present application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for observing the internal flow field motion characteristics of an oil-cooled motor stator cooling system, characterized by: The specific steps include: Step 1: Build a motor stator cooling system experimental platform, including a fully transparent motor experimental device, a fluid measuring element, a fluid delivery pipeline, a power pump, an oil tank, a high-speed camera, a laser, and a support frame; wherein, the motor experimental device consists of a housing and a stator, rotor, winding, cooling components, and corresponding flow channels arranged according to the internal structure of a real motor; a cooling fluid inlet connected to the fluid delivery pipeline and a cooling fluid outlet connected to the oil tank are provided on the transparent housing, and the cooling fluid circulation can be realized under the action of the power pump; the high-speed camera is used to capture the image of the cooling fluid in the motor cooling channel, and the laser is used to form a uniform surface light to illuminate the cooling channel; the high-speed camera and the laser are arranged in a mutually orthogonal layout; the fluid measuring element is installed on the fluid delivery pipeline to measure the parameters of the cooling fluid including flow, temperature, and pressure; Step 2: Complete the relevant preparations for experimental observation, including: adding a specific concentration of tracer particles to the cooling fluid, installing the appropriate filter on the high-speed camera to improve the clarity of the tracer particles in the image; and adjusting the field of view of the high-speed camera and the light field of the laser. Step 3: Start the power pump to form a cooling fluid circulation in the oil tank, fluid delivery pipeline and motor experimental device and start the experiment. At the same time, use a high-speed camera to capture continuous images of the cooling fluid in the cooling channel; Step 4: Process the collected images using particle image velocimetry (PIV) technology to calculate the corresponding velocity field and vortex field data; Step 5: Based on the obtained flow field data, the vorticity and turbulence intensity distribution are calculated, and the flow parameters including streamline characteristics and turbulent kinetic energy are extracted. On this basis, the fluid flow state in the cooling channel is fully characterized and analyzed.

2. The method according to claim 1, wherein: The motor experimental device specifically adopts a double-sided spray cooling structure in which a pair of oil spray rings are installed at both ends of the stator.

3. The method according to claim 1, wherein: The fluid measuring elements include flow meters, thermocouples and pressure gauges.

4. The method according to claim 1, wherein: In step 4, the collected image is also masked to achieve local processing of the flow channel inside the motor to improve the efficiency and accuracy of flow field data extraction and calculation.

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