Method and system for evaluating heat dissipation capability of end winding of oil-cooled motor, and storage medium

Abstract

The invention discloses an oil-cooled motor end winding heat dissipation capability evaluation method, a storage medium and a system, and belongs to the field of oil-cooled motor design. The method for evaluating the heat dissipation capability of the end winding of the oil-cooled motor comprises the steps that according to a geometric model of the oil-cooled motor, finite element analysis software is used for extracting an internal oil way structure of the oil-cooled motor, and the oil flow of an oil injection ring of the oil-cooled motor is calculated; calculating flow field distribution of an internal oil path of the oil-cooled motor and a convective heat transfer coefficient of an end winding by using particle method software; the oil injection ring structure is adjusted, and the convective heat transfer coefficient of the end winding of the adjusted oil cooling motor is calculated; and comparing and adjusting the convective heat transfer coefficients of the front and rear end windings in different regions, and evaluating the heat dissipation capability of the end windings according to a comparison result. According to the method, the temperature conditions of windings at the lower ends of different oil injection ring structures can be quickly compared by comparing the convective heat transfer coefficients, and the simulation time is shortened; and a basis is provided for structure adjustment of the oil injection ring.

Description

Technical Field

[0001] The present invention belongs to the field of oil-cooled motor design, and in particular relates to a method, storage medium and system for evaluating the heat dissipation capacity of end windings of an oil-cooled motor. Background Art

[0002] Oil-cooled motors use direct oil spraying to cool the end windings. This utilizes the oil distribution function of the spray ring, delivering oil through the ring's nozzles to each location on the corresponding winding. Gravity rapidly distributes the oil to other areas, instantly removing a significant amount of heat. The heated oil then returns to the oil pan for collection, cooling it in the oil cooler for further recirculation.

[0003] The heat dissipation capacity of the end windings of oil-cooled motors affects the operating efficiency of the motor system. Therefore, when the heat dissipation capacity of the end windings of oil-cooled motors needs to be evaluated, the traditional evaluation method is to first use the particle method to calculate the flow field distribution of the motor, and then import the motor's flow field data into finite element analysis software to calculate the temperature field of the oil-cooled motor. The heat dissipation effect of the oil-cooled motor is evaluated by analyzing the temperature field changes. However, this evaluation method is computationally difficult and time-consuming. Summary of the Invention

[0004] The technical problem to be solved by the present invention is how to more efficiently evaluate the heat dissipation capacity of the end windings of an oil-cooled motor, and provide a basis for optimizing the oil injection ring structure of the oil-cooled motor.

[0005] To achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0006] In a first aspect, the present application provides a method for evaluating the heat dissipation capacity of an oil-cooled motor end winding, comprising the following steps:

[0007] Obtaining a geometric model of an oil-cooled motor including an oil spray ring structure, extracting an internal oil circuit structure of the oil-cooled motor based on the geometric model of the oil-cooled motor, and calculating an oil flow rate of the oil spray ring of the oil-cooled motor based on the internal oil circuit structure;

[0008] The flow field distribution of the internal oil circuit of the oil-cooled motor is calculated based on the internal oil circuit structure of the oil-cooled motor and the oil flow rate of the oil injection ring, and the convective heat transfer coefficient of the oil-cooled motor is calculated based on the flow field distribution;

[0009] According to the convection heat dissipation coefficient of the oil-cooled motor, the convection heat dissipation coefficient of the end winding of the oil-cooled motor is extracted in different regions;

[0010] Adjust the oil injection ring structure, repeat the above steps of extracting the convection heat transfer coefficient of the end winding of the oil-cooled motor by region, and obtain the adjusted convection heat transfer coefficient of each region of the end winding of the oil-cooled motor;

[0011] The convective heat transfer coefficients of the same end winding zones before and after adjustment were compared, and the heat dissipation capacity of the end winding was evaluated based on the comparison results. The end winding was divided into several zones, including multiple welded ends and multiple crown ends. The convective heat dissipation coefficients of each welded end and crown end zone of the end winding were extracted from the convective heat dissipation coefficients of the oil-cooled motor.

[0012] The evaluating the heat dissipation capacity of the end winding according to the comparison result includes outputting the evaluation result of the heat dissipation capacity of the end winding according to the comparison result of the convective heat dissipation coefficient of each area after adjustment and the convective heat dissipation coefficient of the area before adjustment.

[0013] The oil flow rate of the injection ring remains unchanged before and after the injection ring structure is adjusted.

[0014] The expression of convection heat dissipation coefficient is:

[0015]

[0016]

[0017] Where: q is the heat exchanged between the end winding surface and the oil per unit area per unit time, which is called heat flux density. are the end winding surface temperature and oil temperature respectively; A is the end winding oil spraying area; Q is the heat transfer quantity on the oil spraying area A per unit time; h is the convection heat transfer coefficient.

[0018] The particle method software performs simulation calculations based on the smoothed particle fluid dynamics method of the Lagrangian system.

[0019] In a second aspect, the present application provides a computer-readable storage medium having a computer program / instruction stored thereon. When the computer program / instruction is executed by a processor, the steps of the above-mentioned method for evaluating the heat dissipation capacity of the end winding of an oil-cooled motor are implemented.

[0020] In a third aspect, the present application provides a computer system, comprising:

[0021] Memory, used to store computer programs / instructions;

[0022] A processor is used to execute the computer program / instructions to implement the steps of the above-mentioned method for evaluating the heat dissipation capacity of the end winding of the oil-cooled motor.

[0023] In a fourth aspect, the present application provides a computer program product, comprising a computer program / instruction, which, when executed by a processor, implements the steps of the above-mentioned method for evaluating the heat dissipation capacity of the end winding of an oil-cooled motor.

[0024] Compared to methods that determine the heat dissipation status of end windings based on the overall temperature field of oil-cooled motors, the present invention's technical solution can quickly compare the temperature of end windings under different injection ring structures by comparing the convective heat transfer coefficient. This eliminates the need for complex temperature field calculations and reduces simulation time. The method described in this invention can effectively adjust the injection ring structure of oil-cooled motors, achieving an optimal injection ring nozzle distribution and improving the heat dissipation performance of the motor system. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A flow chart of a method for evaluating the heat dissipation capacity of end windings of oil-cooled motors;

[0026] Figure 2 This is a schematic diagram of the partition state of the end winding in Example 1. DETAILED DESCRIPTION

[0027] In order to elaborate on the technical solutions adopted by the present invention to achieve the predetermined technical objectives, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments, and the technical means or technical features in the embodiments of the present invention can be replaced without creative work. The present invention will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0028] Convective heat transfer refers to the process of heat transfer between a fluid and a solid surface. When a fluid flows over a solid surface, the temperature difference between the fluid and the solid surface causes heat to transfer from the higher temperature area to the lower temperature area, creating a convection heat transfer process. This form of heat transfer is widely used in equipment such as radiators, boilers, and heat exchangers.

[0029] Example 1

[0030] refer to Figure 1 and Figure 2 As shown, a method for evaluating the heat dissipation capacity of the end winding of an oil-cooled motor includes the following steps:

[0031] Step 1: Based on the geometric model of the oil-cooled motor, use finite element analysis software to extract the internal oil circuit structure of the oil-cooled motor, and calculate the oil flow rate of the oil injection ring of the oil-cooled motor based on the internal oil circuit structure;

[0032] Based on the actual oil-cooled motor products, the corresponding geometric model of the oil-cooled motor is constructed. Based on the geometric model of the oil-cooled motor, the volume of the oil pipe part in the model is extracted through the finite element analysis method, and the flow is distributed as a separate oil circuit model. The oil flow of the oil injection ring of the oil-cooled motor is calculated using finite element analysis software.

[0033] Step 2: Based on the internal oil circuit structure of the oil-cooled motor and the oil flow rate of the oil injection ring, use the particle method software to calculate the flow field distribution of the internal oil circuit of the oil-cooled motor, and calculate the convective heat transfer coefficient of the oil-cooled motor based on the flow field distribution;

[0034] The heat transfer coefficient (HTC) is used to characterize the heat transfer capacity between a fluid (oil) and a solid surface (end winding). Its value is closely related to the physical properties of the fluid during the heat transfer process, the shape and location of the heat transfer surface, and the flow rate of the fluid.

[0035] Basic parameters, such as oil temperature, oil physical parameters, and the operating temperature of the oil-cooled motor, are collected during actual operating conditions and entered into particle physics software. The software then calculates the total flow rate at the oil cooler outlet of the oil-cooled motor and simulates the flow field distribution within the motor after oil spraying. Based on this flow field distribution, the oil spraying area of the end windings of the oil-cooled motor is determined, and the motor's convection heat dissipation coefficient is calculated. Entering the collected parameters into the software improves model accuracy, making the calculated results closer to the actual values.

[0036] The convection heat dissipation coefficient is calculated based on Newton's law of cooling, which states that the heat flux of convection heat transfer between the fluid and the solid wall is proportional to the temperature difference between them, that is:

[0037]

[0038]

[0039] Where: q is the heat exchanged between the end winding surface and the oil per unit area per unit time, which is called heat flux density. are the end winding surface temperature and oil temperature respectively; A is the end winding oil spraying area; Q is the heat transfer quantity per unit time on area A; h is the convection heat transfer coefficient.

[0040] Step 3: According to the convection heat dissipation coefficient of the oil-cooled motor, extract the convection heat dissipation coefficient of the end winding of the oil-cooled motor by region;

[0041] Step 4: Adjust the oil injection ring structure and repeat the above steps 1-3 to calculate the convective heat transfer coefficient of each partition of the end winding of the oil-cooled motor after adjustment;

[0042] In this embodiment, the spray holes on the fuel injection ring are evenly distributed before adjustment. During the adjustment process, the number and hole size of the fuel injection rings remain unchanged. Only the positions of the spray holes are changed, and the total oil flow rate at the fuel injection ring remains unchanged.

[0043] Step 5: Compare the convective heat transfer coefficients of the same end winding partitions before and after adjustment, and evaluate the heat dissipation capacity of the end winding based on the comparison results.

[0044] In this embodiment, the end winding is divided into several welding ends and crown ends, and the changes in the corresponding convection heat dissipation coefficients of the same welding ends and crown ends before and after the injection ring structure is adjusted are compared. If the convection heat transfer coefficients of the multiple welding ends after adjustment are all greater than the convection heat transfer coefficients before adjustment, it indicates that the heat dissipation capacity of the welding ends of the end winding is improved; if the convection heat transfer coefficients of the multiple crown ends after adjustment are all greater than the convection heat transfer coefficients before adjustment, it indicates that the heat dissipation capacity of the crown ends of the end winding is improved; at this time, it can be concluded that the heat dissipation capacity of the end winding of the oil-cooled motor is improved.

[0045] refer to Figure 2 As shown in the figure, "1-16" represents the spray hole number on the injection ring, and "w1-w8" represents the partition number of the end winding.

[0046] The following table shows the oil flow rate and convection heat dissipation coefficient in each area of the end winding before and after the oil injection ring structure adjustment.

[0047]

[0048] In this embodiment, the total oil flow rate of the oil injection ring remains unchanged. Given the same winding heat generation, a larger convective heat transfer coefficient indicates greater heat dissipation capacity, indicating better oil cooling of the end windings and lower end winding temperatures. The adjusted oil injection ring structure improves the convective heat dissipation coefficient across all regions of the end winding, demonstrating enhanced heat dissipation capacity.

[0049] It should be noted that the change in the position of the spray hole on the oil injection ring will change the flow distribution in different areas of the end winding, but the total oil flow of the oil injection ring remains unchanged.

[0050] Evaluating the heat dissipation capacity of the end windings provides a basis for structural optimization of the oil injection ring. Directly comparing the convective heat transfer coefficients of the oil and the motor end windings to evaluate the heat dissipation capacity of the motor end windings eliminates the need for additional temperature field calculations, reducing simulation computational complexity and time.

[0051] The particle method is a fluid simulation method based on the Lagrangian system (the system takes moving fluid particles as the research object and focuses on the law of parameter changes of moving fluid particles over time).

[0052] The particle method divides the fluid into a certain number of micro-particles, and by establishing the control equation, solves the interaction between each particle within the range of action, and then obtains the motion law of the fluid.

[0053] Example 2

[0054] A computer-readable storage medium stores a computer program / instruction thereon, which, when executed by a processor, implements the steps of the above-mentioned method for evaluating the heat dissipation capacity of the end winding of an oil-cooled motor.

[0055] Example 3

[0056] A computer system includes: a memory for storing computer programs / instructions; and a processor for executing the computer programs / instructions to implement the steps of the above-mentioned method for evaluating the heat dissipation capacity of the end windings of an oil-cooled motor.

[0057] Example 4

[0058] A computer program product includes a computer program / instruction, which, when executed by a processor, implements the steps of the above-mentioned method for evaluating the heat dissipation capacity of the end winding of an oil-cooled motor.

[0059] To sum up, compared with the method of judging the heat dissipation status of the end winding based on the entire temperature field of the oil-cooled motor, the technical solution of the present invention can quickly compare the temperature conditions of the end winding under different injection ring structures by comparing the convection heat transfer coefficient. There is no need to perform complex temperature field calculations, which shortens the simulation time. The heat dissipation capacity evaluation method of the end winding of the oil-cooled motor of the present invention can guide the adjustment of the injection ring structure of the oil-cooled motor, obtain the optimal injection ring spray hole distribution, and improve the heat dissipation performance of the motor system.

[0060] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0061] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1A device that provides the functions specified in a block or multiple blocks.

[0062] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0063] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0064] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which are all protected by the present invention.

Claims

1. A method for evaluating the heat dissipation capacity of the end winding of an oil-cooled motor, characterized in that: The steps include: Obtaining a geometric model of an oil-cooled motor including an oil spray ring structure, extracting an internal oil circuit structure of the oil-cooled motor based on the geometric model of the oil-cooled motor, and calculating an oil flow rate of the oil spray ring of the oil-cooled motor based on the internal oil circuit structure; The flow field distribution of the internal oil circuit of the oil-cooled motor is calculated based on the internal oil circuit structure of the oil-cooled motor and the oil flow rate of the oil injection ring, and the convective heat transfer coefficient of the oil-cooled motor is calculated based on the flow field distribution; According to the convection heat dissipation coefficient of the oil-cooled motor, the convection heat dissipation coefficient of the end winding of the oil-cooled motor is extracted in different regions; Adjust the oil injection ring structure, repeat the above steps of extracting the convection heat transfer coefficient of the end winding of the oil-cooled motor by region, and obtain the adjusted convection heat transfer coefficient of each region of the end winding of the oil-cooled motor; The convective heat transfer coefficients of the same end winding partitions before and after adjustment are compared, and the heat dissipation capacity of the end winding is evaluated based on the comparison results.

2. The method for evaluating the heat dissipation capacity of the end winding of an oil-cooled motor according to claim 1, characterized in that: The end winding is divided into several areas, including multiple welding ends and multiple crown ends, and the convection heat dissipation coefficient in each welding end and crown end area on the end winding is extracted from the convection heat dissipation coefficient of the oil-cooled motor.

3. The method for evaluating the heat dissipation capacity of the end winding of an oil-cooled motor according to claim 1, characterized in that: The evaluating the heat dissipation capacity of the end winding according to the comparison result includes outputting the evaluation result of the heat dissipation capacity of the end winding according to the comparison result of the convective heat dissipation coefficient of each area after adjustment and the convective heat dissipation coefficient of the area before adjustment.

4. The method for evaluating the heat dissipation capacity of the end winding of an oil-cooled motor according to claim 1, characterized in that: The oil flow rate of the injection ring remains unchanged before and after the injection ring structure is adjusted.

5. The method for evaluating the heat dissipation capacity of the end winding of an oil-cooled motor according to claim 1, wherein: The expression of convection heat dissipation coefficient is: Where: q is the heat exchanged between the end winding surface and the oil per unit area per unit time, which is called heat flux density. are the end winding surface temperature and oil temperature respectively; A is the end winding oiling area; Q is the heat transfer quantity on the oiling area A per unit time; h is the convection heat transfer coefficient.

6. The method for evaluating the heat dissipation capacity of the end winding of an oil-cooled motor according to claim 1, characterized in that: The particle method software performs simulation calculations based on the smoothed particle fluid dynamics method of the Lagrangian system.

7. A computer-readable storage medium having a computer program / instruction stored thereon, characterized in that: When the computer program / instruction is executed by a processor, the steps of the method for evaluating the heat dissipation capacity of the end winding of an oil-cooled motor according to any one of claims 1 to 6 are implemented.

8. A computer system, characterized in that: include: Memory, used to store computer programs / instructions; A processor is used to execute the computer program / instructions to implement the steps of the method for evaluating the heat dissipation capacity of the end winding of an oil-cooled motor according to any one of claims 1 to 6.

9. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instruction is executed by a processor, the steps of the method for evaluating the heat dissipation capacity of the end winding of an oil-cooled motor according to any one of claims 1 to 6 are implemented.

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