Optimization design method, system and equipment for heat exchange sheet structure of air cooler of generator and medium

Abstract

The invention discloses an optimization design method, system and equipment for a heat exchange sheet structure of an air cooler of a generator and a medium, and belongs to the technical field of generator cooling, and the optimization design method comprises the steps of obtaining a target heat exchange coefficient and an allowable flow pressure drop; a turbulent flow strengthening structure and a flow resistance optimizing structure are arranged in the three-dimensional model of the whole fin-penetrating type heat exchange fin; establishing a computational fluid dynamics simulation model comprising the heat exchange fins and the cooling pipes, and setting boundary conditions; performing flow field solution and heat transfer solution to obtain velocity field distribution, pressure field distribution and temperature field distribution; calculating a heat exchange coefficient and a flowing pressure drop; judging whether performance requirements are met or not, if not, adjusting structural parameters and then resolving, and if yes, outputting an optimization design result. According to the method, the problems that traditional design depends on experience, performance prediction is inaccurate, and system optimization is lacked are solved, and automatic optimization of the heat exchange fin structure is achieved.

Description

Technical Field

[0001] This invention relates to the field of generator cooling technology, specifically to an optimized design method, system, equipment, and medium for the heat exchanger fin structure of a generator air cooler. Background Technology

[0002] As a crucial component of the generator's ventilation and cooling system, the generator air cooler's heat exchange performance directly impacts the generator's operating efficiency and lifespan. Traditional generator air coolers often employ bimetallic spiral finned tubes as heat exchange elements. This structure creates a heat exchange surface by spirally winding metal fins around the outer wall of the cooling tube. However, bimetallic spiral finned tubes suffer from limited heat exchange area and poor overall rigidity. Furthermore, during long-term operation, they are prone to issues such as thinning of the cooling tube wall and leakage at the tube-plate connections, severely affecting the generator's safe and stable operation.

[0003] With the continuous increase in the single-unit capacity of power generation equipment, higher requirements are being placed on the heat exchange capacity per unit volume of gas coolers. Due to their large heat dissipation area and high heat exchange efficiency, integral finned heat exchange elements are gradually becoming the preferred choice for generator coolers. However, the structural design of integral finned heat exchange elements directly determines the heat exchange performance and flow resistance of the cooler. How to rationally incorporate turbulence-enhancing structures on the heat exchange elements to improve heat exchange efficiency, while simultaneously reducing medium flow resistance through optimized design, is a pressing technical problem that needs to be solved in the current field of generator cooler design.

[0004] Existing heat exchanger designs mainly rely on designers' experience and simple theoretical calculations, lacking systematic optimization design methods, making it difficult to achieve an optimal balance between heat exchange efficiency and flow resistance. Although computational fluid dynamics technology has been applied in heat exchanger design, optimization design methods for generator air cooler heat exchanger structures, especially the collaborative design methods for turbulence enhancement structures and flow resistance optimization structures, are still imperfect. Summary of the Invention

[0005] In view of the above-mentioned problems, the present invention provides an optimized design method, system, equipment and medium for the heat exchanger fin structure of a generator air cooler.

[0006] Therefore, the technical problem solved by this invention is: how to systematically optimize the turbulence enhancement structure and flow resistance optimization structure of the heat exchange fins of a generator air cooler through computational fluid dynamics simulation technology, so as to improve heat exchange efficiency while reducing flow resistance and achieve synergistic optimization of heat exchange performance and flow characteristics.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: an optimization design method for the heat exchange fin structure of a generator air cooler, comprising: obtaining the heat exchange performance requirements of the generator air cooler, wherein the heat exchange performance requirements include a target heat transfer coefficient and an allowable flow pressure drop; In the three-dimensional model of the entire through-plate heat exchanger, a turbulence enhancement structure and a flow resistance optimization structure are set. The turbulence enhancement structure includes an initial turbulence section and a turbulence structure around the tube hole. The flow resistance optimization structure includes an opening structure distributed along the circumference of the tube hole. A computational fluid dynamics simulation model including the heat exchanger and cooling pipe is established, and the inlet velocity, inlet temperature and outlet pressure of the medium are set as boundary conditions. The flow field and heat transfer are solved by the simulation model to obtain the velocity field distribution, pressure field distribution and temperature field distribution when the medium flows through the heat exchange plate; The heat transfer coefficient of the heat exchange plate is calculated based on the velocity field distribution and the temperature field distribution, and the flow pressure drop of the medium flowing through the heat exchange plate is calculated based on the pressure field distribution. Determine whether the heat transfer coefficient reaches the target heat transfer coefficient and whether the flow pressure drop is less than the allowable flow pressure drop. If not, adjust the structural parameters of the turbulence enhancement structure and the structural parameters of the flow resistance optimization structure, and then re-solve the flow field and heat transfer. If satisfied, output the current structural parameters as the optimization design result.

[0008] As a preferred embodiment of the optimized design method for the heat exchanger structure of a generator air cooler according to the present invention, the step of setting the turbulence enhancement structure and the flow resistance optimization structure in the three-dimensional model of the entire through-plate heat exchanger includes determining the position of the medium inflow end on the heat exchanger and setting the initial turbulence section at the medium inflow end. Determine the position of the tube hole on the heat exchange plate, and set a flow-deflecting structure around the tube hole; Multiple openings are made on the heat exchange plate along the circumferential direction of the tube hole to form the flow resistance optimization structure.

[0009] As a preferred embodiment of the optimized design method for the heat exchanger fin structure of a generator air cooler according to the present invention, the step of setting the initial turbulence section at the medium inflow end includes stamping a first protrusion structure at the medium inflow end of the heat exchanger fin and setting the geometric dimension parameters of the first protrusion structure. The provision of a flow-disrupting structure around the pipe hole includes: A second protrusion structure is formed by stamping around the tube hole, and the geometric dimensional parameters of the second protrusion structure are set.

[0010] The beneficial effects of this preferred technical solution are as follows: by stamping a first protruding structure at the medium inflow end and stamping a second protruding structure around the pipe hole, a zoned design for enhanced turbulence is achieved. The first protruding structure causes the boundary layer to transform into a turbulent state in advance, while the second protruding structure generates high-intensity vortices near the pipe wall. By independently adjusting the geometric dimensional parameters of the two protruding structures, a refined design is achieved.

[0011] As a preferred embodiment of the optimized design method for the heat exchanger fin structure of a generator air cooler according to the present invention, wherein: opening multiple openings on the heat exchanger fin along the circumferential direction of the tube hole includes determining the fan-shaped angle value of a single opening; Determine the number of openings to be made around the tube hole; The distribution position of each opening is determined in the circumferential direction of the tube hole based on the number of openings. Openings are punched on the heat exchange plate according to the stated sector angle value and the stated distribution position, and the edges of each opening are machined into an arc shape.

[0012] As a preferred embodiment of the optimized design method for the heat exchanger structure of a generator air cooler according to the present invention, the step of establishing a computational fluid dynamics simulation model including the heat exchanger and the cooling pipe includes meshing the three-dimensional geometric model of the heat exchanger and the cooling pipe to generate a computational mesh. Select the turbulence model and set the fluid property parameters; The inner wall of the cooling pipe is set as a constant temperature wall, and the surface of the heat exchange plate is set as an insulating wall. Set the medium inlet to a velocity inlet, and input the inlet flow rate and inlet temperature of the medium; Set the medium outlet to a pressure outlet and enter the outlet pressure value.

[0013] As a preferred embodiment of the optimized design method for the heat exchanger structure of a generator air cooler according to the present invention, the step of calculating the heat transfer coefficient of the heat exchanger based on the velocity field distribution and the temperature field distribution includes extracting the temperature values ​​of each node on the outer wall of the cooling pipe and the medium temperature values ​​of each node in the heat exchanger region. Calculate the temperature difference between the outer wall temperature of the cooling pipe and the temperature of the medium; Extract the heat flux density data of the outer wall surface of the cooling pipe; Dividing the heat flux density by the temperature difference yields the local heat transfer coefficient; The average heat transfer coefficient of the heat exchange plate is obtained by taking the area-weighted average of the local heat transfer coefficients of the outer wall of the cooling pipe.

[0014] The beneficial effects of this preferred technical solution are as follows: by extracting the temperature distribution of the pipe wall and the medium, calculating the temperature difference and combining it with the heat flux density to calculate the heat transfer coefficient, and by using the local heat transfer coefficient plus area weighted average method, it is possible to identify the weak heat transfer area and provide a precise optimization direction.

[0015] As a preferred embodiment of the optimized design method for the heat exchanger fin structure of a generator air cooler according to the present invention, the geometric dimensional parameters of the first protrusion structure include the protrusion height and tilt angle of the first protrusion structure. The geometrical parameters of the second protrusion structure include the protrusion height and the annular width of the second protrusion structure.

[0016] This invention provides an optimized design system for the heat exchanger fin structure of a generator air cooler.

[0017] To solve the above-mentioned technical problems, the present invention provides the following technical solution: an optimized design system for the heat exchanger fin structure of a generator air cooler, comprising: a parameter input module for receiving the heat exchange performance requirements of the generator air cooler; The geometric modeling module is used to create a three-dimensional model of the entire through-plate heat exchanger, and to set up turbulence enhancement structures and flow resistance optimization structures in the three-dimensional model; The simulation model building module is used to build a computational fluid dynamics simulation model that includes the heat exchanger and cooling pipe; The flow field solution module is used to solve the flow field and heat transfer of the simulation model to obtain the velocity field distribution, pressure field distribution and temperature field distribution. The performance calculation module is used to calculate the heat transfer coefficient and flow pressure drop based on the velocity field distribution, the pressure field distribution, and the temperature field distribution. The optimization judgment module is used to determine whether the heat transfer coefficient and the flow pressure drop meet the heat transfer performance requirements. If they do not meet the requirements, the structural parameters are adjusted. If they do meet the requirements, the optimization design results are output.

[0018] The present invention provides a computer device, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps of the optimized design method for the heat exchanger fin structure of a generator air cooler.

[0019] The present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the method for optimizing the design of a heat exchanger structure for a generator air cooler.

[0020] The beneficial effects of this invention are as follows: By parametrically setting the turbulence enhancement structure and the flow resistance optimization structure in the three-dimensional model of the heat exchange plate, the adjustable design of the structure is realized. The turbulence enhancement structure destroys the laminar boundary layer at the medium inflow end and forms a strong vortex around the tube hole. The flow resistance optimization structure reduces the flow resistance and improves the heat transfer on the leeward side through the opening. Compared with empirical design methods, it provides a flexible optimization platform.

[0021] By obtaining the velocity, pressure, and temperature field distributions through computational fluid dynamics simulation, the heat transfer coefficient and flow pressure drop can be accurately calculated. Compared with empirical formulas, it can capture the influence of complex geometries on the flow field and provide a scientific basis for structural optimization.

[0022] By establishing an optimization judgment mechanism and adopting parameter adjustment and iterative solution, the automatic optimization of the heat exchanger structure was achieved. Compared with the trial and error design method, the R&D cycle was shortened and a large amount of physical prototype testing costs were avoided.

[0023] By implementing the optimization method as a computer program, the design process is automated and standardized, reducing reliance on designers' experience and improving design efficiency. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a general flowchart of an optimized design method for the heat exchanger fin structure of a generator air cooler, provided as an embodiment of the present invention. Detailed Implementation

[0026] To make the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0027] Example 1, referring to Figure 1 This is one embodiment of the present invention, which provides an optimized design method for the heat exchanger fin structure of a generator air cooler, comprising: Step 1: Obtain the heat transfer performance requirements of the generator air cooler, including the target heat transfer coefficient and allowable flow pressure drop; Step 2: Set up a turbulence enhancement structure and a flow resistance optimization structure in the three-dimensional model of the entire through-plate heat exchanger. The turbulence enhancement structure includes an initial turbulence section and a turbulence structure around the tube hole. The flow resistance optimization structure includes an opening structure distributed along the circumference of the tube hole. Step 3: Establish a computational fluid dynamics simulation model including heat exchange fins and cooling pipes, and set the inlet velocity, inlet temperature and outlet pressure of the medium as boundary conditions; Step 4: Solve the flow field and heat transfer of the simulation model to obtain the velocity field distribution, pressure field distribution and temperature field distribution when the medium flows through the heat exchanger. Step 5: Calculate the heat transfer coefficient of the heat exchanger plate based on the velocity field distribution and temperature field distribution, and calculate the flow pressure drop of the medium flowing through the heat exchanger plate based on the pressure field distribution; Step 6: Determine whether the heat transfer coefficient reaches the target heat transfer coefficient and whether the flow pressure drop is less than the allowable flow pressure drop. If not, adjust the structural parameters of the turbulence enhancement structure and the flow resistance optimization structure, and then re-solve the flow field and heat transfer. If satisfied, output the current structural parameters as the optimization design result.

[0028] Traditional generator air cooler heat exchanger design relies primarily on designers' experience and simple theoretical calculations, making it difficult to accurately predict the impact of complex flow disturbances on the flow and temperature fields. This often results in insufficient heat exchange efficiency or excessive flow resistance in the designed heat exchangers. When heat exchange efficiency is insufficient, the generator stator temperature rises excessively, and the insulation material ages faster, shortening its service life. When flow resistance is excessive, fan energy consumption increases and operating noise exceeds standards. Existing design methods lack a systematic optimization mechanism, allowing performance verification only through physical testing after prototype manufacturing. If requirements are not met, redesign and manufacturing are necessary, leading to long development cycles and high costs.

[0029] This embodiment establishes a parameterized three-dimensional model of the heat exchanger, incorporating adjustable turbulence enhancement and flow resistance optimization structures. Computational fluid dynamics simulation technology is used to obtain detailed flow and temperature field distributions, accurately calculating the heat transfer coefficient and flow pressure drop. An iterative optimization mechanism constrained by performance requirements is established, enabling the rapid identification of optimal structural parameters that meet performance requirements during the design phase. This method solves the problems of traditional design relying on experience, inaccurate performance prediction, and lack of system optimization. It achieves scientific design and automated optimization of the heat exchanger structure, shortening the R&D cycle and reducing prototype manufacturing costs.

[0030] Example 2, an embodiment of the present invention, provides an optimized design method for the heat exchanger fin structure of a generator air cooler based on the previous embodiment, including: Step 2: In the three-dimensional model of the entire through-plate heat exchanger, a turbulence enhancement structure and a flow resistance optimization structure are set. The turbulence enhancement structure includes an initial turbulence section and a turbulence structure around the tube hole. The flow resistance optimization structure includes an opening structure distributed along the circumference of the tube hole, including the following steps A1-A3: A1: Determine the location of the medium inflow end on the heat exchange plate and set an initial turbulence section at the medium inflow end; A2: Determine the position of the tube hole on the heat exchange plate, and set up a flow disturbance structure around the tube hole; A3: Multiple openings are made on the heat exchange plate along the circumference of the tube hole to form a flow resistance optimization structure.

[0031] In this embodiment of the application, in step A2, the flow disturbance structure around the pipe hole is set by: determining the inner radius and outer radius of the annular region around the pipe hole according to the center coordinates and radius of the pipe hole; forming a second protrusion structure on the surface of the heat exchange plate in the annular region by a stamping process; dividing the second protrusion structure into multiple independent protrusion units along the circumference of the pipe hole; maintaining a gap between each protrusion unit to form a medium flow channel; and setting the protrusion height parameter and annular width parameter for each protrusion unit.

[0032] In an optional implementation, in step A2, the flow disturbance structure around the pipe hole can be set by: forming multiple arc-shaped flange structures on the surface of the heat exchange fins around the pipe hole through a stamping process. The arc-shaped flange structures are evenly distributed along the circumference of the pipe hole, and the flange direction of each arc-shaped flange structure faces the medium flow direction. The flange height and flange width of the arc-shaped flange structure are set as adjustable parameters.

[0033] In another optional implementation, in step A2, the flow disturbance structure around the tube hole can also be set by: forming multiple secondary holes on the surface of the heat exchange plate around the tube hole through a punching process. The secondary holes are distributed in a ring array along the circumference of the tube hole. The diameter of the secondary holes and the distance from the center of the tube hole are set as adjustable parameters. The secondary holes cause the medium to generate a local jet effect when flowing around the tube hole.

[0034] In this embodiment of the application, in step A3, the flow resistance optimization structure is formed by: uniformly marking the center positions of multiple openings along the circumferential direction on the heat exchange plate around the tube hole; the center angle position of each opening is evenly distributed according to the number of openings; extending half a fan-shaped angle value from each center position to both sides to form the boundary line of the fan-shaped opening; removing the heat exchange plate material along the boundary line by a punching process to form the opening; and using a rounded corner transition treatment at the edge of the opening to form an arc-shaped edge.

[0035] In an optional implementation, in step A3, the flow resistance optimization structure can be formed by: setting non-uniformly distributed openings along the circumferential direction on the heat exchange fins around the tube hole, setting a smaller number of openings on the windward side of the mainstream medium direction to maintain structural strength, setting a larger number of openings on the leeward side to improve the heat exchange performance of the vortex region, and setting the fan-shaped angle of each opening differently according to its circumferential position.

[0036] In another alternative implementation, in step A3, the flow resistance optimization structure can also be formed by: when opening a fan-shaped opening on the heat exchange plate around the tube hole, designing the opening edge as wavy rather than arc-shaped, the wavy edge is formed by multiple arc segments connected alternately, the wavy edge generates additional vortex disturbance at the opening boundary, and the wavelength and amplitude of the wave are adjustable parameters.

[0037] In step A1, an initial turbulence section is set at the medium inflow end, including the following steps A11-A13: A11 forms a first protrusion structure by stamping at the medium inflow end of the heat exchange plate, and sets the geometric dimension parameters of the first protrusion structure; A12 includes a flow-disrupting structure around the pipe orifice, including: A13 is formed by stamping a second protrusion around the tube hole, and the geometric dimensional parameters of the second protrusion are set.

[0038] In step A2, multiple openings are made on the heat exchange plate along the circumferential direction of the tube hole, including the following steps A21-A23: A21: Determine the sector angle value for a single opening; A22: Determine the number of openings to be made around the pipe hole; A23: Determine the distribution position of each opening in the circumferential direction of the pipe hole based on the number of openings; A24: Punch openings on the heat exchange fins according to the fan-shaped angle value and distribution position, and process the edge of each opening into an arc shape.

[0039] It should be noted that the geometrical parameters of the first protrusion structure include the protrusion height and tilt angle of the first protrusion structure; the geometrical parameters of the second protrusion structure include the protrusion height and annular width of the second protrusion structure.

[0040] Step 3: Establish a computational fluid dynamics simulation model including heat exchange fins and cooling pipes, setting the inlet velocity, inlet temperature, and outlet pressure of the medium as boundary conditions, including the following steps B1-B5: B1: Mesh the three-dimensional geometric model of the heat exchanger and cooling pipes to generate a computational mesh; B2: Select the turbulence model and set the fluid property parameters; B3: Set the inner wall of the cooling pipe as a constant temperature wall and the surface of the heat exchange plate as an adiabatic wall; B4: Set the medium inlet to a velocity inlet, and input the inlet flow rate and inlet temperature of the medium; B5: Set the medium outlet to a pressure outlet and enter the outlet pressure value.

[0041] In this embodiment, in step 3, the computational fluid dynamics simulation model extracts the fluid domain from the geometric model of the heat exchanger containing the turbulence enhancement structure and the flow resistance optimization structure; adopts a boundary layer mesh on the surface of the heat exchanger and the outer wall of the cooling pipe; sets the first layer height of the boundary layer mesh so that the dimensionless distance of the near-wall mesh meets the requirements of the turbulence model; performs local mesh refinement around the turbulence structure and the opening structure; selects the SSTk-ω turbulence model and sets the density, dynamic viscosity, specific heat capacity and thermal conductivity of the medium; sets the inner wall temperature of the cooling pipe as the average value of the inlet and outlet temperatures of the cooling water; sets the surface of the heat exchanger as an adiabatic boundary; applies velocity boundary conditions at the medium inlet and inputs the flow velocity and temperature values; and applies pressure boundary conditions at the medium outlet.

[0042] In an optional implementation, in step 3, the computational fluid dynamics simulation model can be modified by: replacing the SSTk-ω turbulence model with the standard k-ε turbulence model, using the standard wall function to process the boundary layer near the wall, adjusting the height of the first layer of the near-wall mesh accordingly so that the dimensionless distance meets the applicable range of the wall function, and setting the remaining boundary conditions and physical property parameters in the same way as in the implementation of this application.

[0043] In another alternative implementation, in step 3, the computational fluid dynamics simulation model can also be: using a large eddy simulation turbulence model to perform time-dependent transient solutions on the eddy structure around the heat exchanger, using a finer grid in space to distinguish the eddy scale, setting a time step in time to capture the dynamic evolution of the eddy, and obtaining the statistically significant velocity field, pressure field, and temperature field distribution by averaging the transient results over time.

[0044] Step 5: Calculating the heat transfer coefficient of the heat exchanger based on the velocity and temperature field distributions, and calculating the pressure drop of the medium flowing through the heat exchanger based on the pressure field distribution, includes the following steps C1-C5: C1: Extract the temperature values ​​of each node on the outer wall of the cooling pipe and the medium temperature values ​​of each node in the heat exchanger area; C2: Calculate the temperature difference between the outer wall temperature of the cooling pipe and the temperature of the medium; C3: Extract heat flux density data from the outer wall of the cooling pipe; C4: Divide the heat flux density by the temperature difference to obtain the local heat transfer coefficient; C5: The average heat transfer coefficient of the heat exchanger is obtained by taking the area-weighted average of the local heat transfer coefficients of the outer wall of the cooling pipe.

[0045] In this embodiment, step 5 calculates the heat transfer coefficient of the heat exchanger by: exporting the temperature data and heat flux density data of all grid nodes on the outer wall of the cooling pipe from the simulation results; for each wall node, extracting the medium temperature of the fluid node closest to the wall in its normal direction; calculating the difference between the temperature of the wall node and the temperature of the corresponding fluid node as the local temperature difference; dividing the heat flux density of the node by the local temperature difference to obtain the local heat transfer coefficient of the node; dividing the outer wall of the cooling pipe into multiple micro-areas; taking the average local heat transfer coefficient in each micro-area; and summing the products of the local heat transfer coefficients of all micro-areas and their corresponding areas and dividing by the total area to obtain the average heat transfer coefficient.

[0046] In an optional implementation, in step 5, the heat transfer coefficient of the heat exchanger can be calculated by: calculating the medium temperature using the volume averaging method, setting a reference control volume near the outer wall of the cooling pipe, the control volume extending along the cooling pipe axis and covering the spacing range of the heat exchanger, performing a volume-weighted average of the temperatures of all fluid nodes within the control volume to obtain the reference medium temperature, taking the difference between the average temperature of the outer wall of the cooling pipe and the reference medium temperature as the temperature difference, and dividing the total heat transfer of the outer wall of the cooling pipe by the total wall area and the temperature difference to obtain the average heat transfer coefficient.

[0047] In another optional implementation, in step 5, the heat transfer coefficient of the heat exchanger can also be calculated by dividing the outer wall of the cooling pipe into three regions according to the circumferential position: the windward side, the side side, and the leeward side. The local average heat transfer coefficient of each region is calculated separately. By comparing the differences in the heat transfer coefficients of the three regions, weak heat transfer areas are identified. For the leeward side region with a lower heat transfer coefficient, the flow resistance optimization structural parameters of that region are adjusted to achieve targeted optimization of heat transfer performance.

[0048] It should be noted that the target heat transfer coefficient is calculated using the heat balance equation based on the generator stator's heat load and the cooling medium's temperature parameters. Specifically, the heat required to be transferred per unit heat exchange area is calculated based on the total heat generation power of the generator stator windings, the mass flow rate of the cooling medium, and the temperature difference. The required heat transfer coefficient value is then determined using heat transfer formulas. The allowable flow pressure drop is determined based on the performance curve of the generator's matching fan. At the fan's rated speed, the allowable pressure drop value allocated to the heat exchange fins is determined based on the difference between the total pressure provided by the fan and the pressure drop across the pipes before and after the cooler.

[0049] Furthermore, the determination of the target heat transfer coefficient also considers the arrangement of heat exchange fins and the number of cooling pipes. The total heat load of the generator stator is divided by the proportion of heat load borne by a single cooler, and then divided by the total heat exchange area of ​​the single cooler to obtain the heat transfer per unit area. This is then combined with the logarithmic mean temperature difference method to calculate the target heat transfer coefficient. The determination of the allowable flow pressure drop also considers the noise limits of generator operation. If the flow pressure drop is too large, causing the fan speed to increase, the operating noise may exceed the standard. Therefore, it is necessary to control the flow pressure drop within a reasonable range while meeting the heat exchange requirements.

[0050] It should be noted that adjusting the structural parameters of the turbulence enhancement structure and the flow resistance optimization structure includes: when the calculated heat transfer coefficient is lower than the target heat transfer coefficient, increasing the bulge height of the first bulge structure or increasing the bulge height of the second bulge structure to enhance the turbulence effect; when the calculated flow pressure drop is greater than the allowable flow pressure drop, increasing the fan-shaped angle value of the opening or increasing the number of openings to reduce flow resistance.

[0051] Furthermore, sensitivity analysis was used to determine the direction and magnitude of structural parameter adjustments. Specifically, small-amplitude perturbations were made to the height of the first and second protrusions, the fan-shaped angle of the openings, and the number of openings. The impact of each parameter change on the heat transfer coefficient and flow pressure drop was calculated. The parameter with the greatest impact on the performance indicators that did not meet the requirements was selected for adjustment, with the adjustment range being 5% to 20% of the current value of that parameter.

[0052] Furthermore, when neither the heat transfer coefficient nor the flow pressure drop meets the requirements, a multi-objective optimization strategy is adopted to adjust multiple structural parameters simultaneously. Deviation weights for the heat transfer coefficient and flow pressure drop are set. Based on the relative deviations between the current heat transfer coefficient and the target heat transfer coefficient, and the relative deviations between the current flow pressure drop and the allowable flow pressure drop, the comprehensive optimization objective is calculated using weighted coefficients. A gradient descent method or genetic algorithm is then used to search for the combination of structural parameters that minimizes the comprehensive optimization objective.

[0053] It should be noted that the first and second protruding structures are formed by die stamping. The first protruding structure is wavy or serrated and distributed laterally along the medium inflow end. Each protruding unit protrudes upward from the heat exchange fin base surface, and the cross-section of the protrusion is trapezoidal or arc-shaped. The second protruding structure is distributed in a ring or arc shape around the pipe hole. Each protruding unit protrudes radially along the pipe hole, and the cross-section of the protrusion is rectangular or semi-circular.

[0054] Furthermore, the inclination angle of the first protrusion structure is the angle between the protruding surface and the base surface of the heat exchange fin. This angle affects the degree of disturbance when the medium flows through the protrusion structure. If the inclination angle is too small, the turbulence effect will be insignificant; if the inclination angle is too large, the flow resistance will be too high. The preferred inclination angle range is 20 degrees to 45 degrees. The annular width of the second protrusion structure is the extension length of the protrusion unit along the radial direction of the pipe hole. The annular width affects the range of the turbulence area around the pipe hole. The preferred annular width is 15% to 35% of the pipe hole radius.

[0055] Specifically, the stamping process includes the following steps: placing the heat exchanger material on the lower die of the stamping die, the surface of the lower die having grooves corresponding to the first and second protruding structures, and the surface of the upper die having corresponding bosses. The upper die is driven downward by a press, causing the heat exchanger material to undergo plastic deformation between the upper die boss and the lower die groove, forming a protruding structure. After stamping is completed, the upper die is springed back, and the heat exchanger with the protruding structure is removed.

[0056] It should be noted that the sector angle of a single opening is determined comprehensively based on the requirements for flow resistance optimization and structural strength. If the sector angle is too small, the flow resistance reduction effect is not significant; if the sector angle is too large, the structural strength of the heat exchange fins at the opening is insufficient. The preferred sector angle range is 30 to 90 degrees. The number of openings is calculated based on the perimeter of the tube orifice and the sector angle of a single opening. Provided that sufficient support structure is provided between adjacent openings, a greater number of openings results in a better flow resistance reduction effect. The preferred number of openings ranges from 4 to 12.

[0057] Furthermore, the distribution of each opening is preferably uniformly distributed circumferentially, with the 360-degree circumference of the orifice evenly allocated to each opening, ensuring that the center angle positions of each opening are equally spaced. When optimization is required for a specific flow direction, a non-uniform distribution method can be adopted, with more or larger openings placed on the leeward side of the orifice to improve the flow field and temperature field distribution in that area.

[0058] Specifically, the radius of the rounded corners is determined based on the thickness of the heat exchanger material and the opening size. A radius that is too small will cause stress concentration at the opening edge, while a radius that is too large will affect the effective area of ​​the opening. Preferably, the radius is 2 to 5 times the thickness of the heat exchanger. After the punching process, a deburring process is used to treat the opening edge, removing burrs and sharp edges generated during punching to ensure a smooth transition.

[0059] It should be noted that the height of the first layer of the boundary layer mesh is determined based on the selected turbulence model type. When using the SSTk-ω turbulence model, the dimensionless distance y+ of the near-wall mesh is required to be less than 1. The formula for calculating the height of the first layer mesh is: First layer height = y+ × dynamic viscosity / (density × wall friction velocity), where the wall friction velocity is estimated based on the inlet velocity. When using the standard k-ε turbulence model with wall functions, the y+ value is required to be between 30 and 300, and the height of the first layer mesh should be adjusted accordingly to meet this range.

[0060] Furthermore, the local mesh refinement area includes the surface of the first raised structure, the surface of the second raised structure, and the opening edge region. On the windward and leeward sides of the raised structure, the mesh size is controlled at 10% to 20% of the raised height to accurately capture the vortices induced by the raised structure. Around the opening edge, within a range of one opening width, the mesh size is controlled at 5% to 15% of the opening width to accurately simulate the flow details of the medium passing through the opening.

[0061] It should be noted that when extracting the medium temperature of the fluid node closest to the wall in its normal direction, the normal direction is perpendicular to the outer wall of the cooling pipe. For each grid node on the outer wall of the cooling pipe, the nearest fluid domain grid node is searched along the outward normal direction of that node, and the temperature of that fluid node is taken as the medium temperature corresponding to that wall node. When there are multiple fluid nodes that are close to the wall node, the temperatures of these fluid nodes are averaged by distance to obtain the medium temperature corresponding to that wall node.

[0062] Furthermore, the method for dividing the micro-element area is as follows: the outer wall of the cooling pipe is divided into multiple grid units according to the grid topology relationship, each grid unit is a micro-element area, the local heat transfer coefficient at the center point of each grid unit is calculated, the local heat transfer coefficient is multiplied by the area of ​​the grid unit to obtain the heat transfer contribution of the micro-element, and the sum of the heat transfer contributions of all micro-elements is divided by the total wall area to obtain the average heat transfer coefficient.

[0063] It should be noted that the pressure drop of the medium flowing through the heat exchanger is calculated based on the pressure field distribution by: extracting the total pressure data of all nodes at the medium inlet boundary and calculating the area-weighted average of the inlet total pressure as the inlet average total pressure; extracting the total pressure data of all nodes at the medium outlet boundary and calculating the area-weighted average of the outlet total pressure as the outlet average total pressure; and using the difference between the inlet average total pressure and the outlet average total pressure as the pressure drop of the medium flowing through the heat exchanger. Furthermore, the total pressure is the sum of the static pressure and the dynamic pressure, with the dynamic pressure calculated based on the velocity vectors of the nodes. When calculating the area-weighted average, the total pressure of each boundary node is multiplied by the area unit corresponding to that node, and the sum of the weighted values ​​of all nodes is divided by the total boundary area. When the velocity distribution at the inlet or outlet boundary is uneven, using the total pressure instead of the static pressure to calculate the pressure drop can more accurately reflect the flow energy loss.

[0064] Example 3 is an embodiment of the present invention, which provides an optimized design system for the heat exchanger fin structure of a generator air cooler, comprising: The parameter input module is used to receive the heat exchange performance requirements of the generator air cooler. The geometric modeling module is used to create a three-dimensional model of the entire through-plate heat exchanger, and to set up turbulence enhancement structures and flow resistance optimization structures in the three-dimensional model; The simulation model building module is used to build a computational fluid dynamics simulation model that includes the heat exchanger and cooling pipe; The flow field solution module is used to solve the flow field and heat transfer of the simulation model to obtain the velocity field distribution, pressure field distribution and temperature field distribution. The performance calculation module is used to calculate the heat transfer coefficient and flow pressure drop based on the velocity field distribution, the pressure field distribution, and the temperature field distribution. The optimization judgment module is used to determine whether the heat transfer coefficient and the flow pressure drop meet the heat transfer performance requirements. If they do not meet the requirements, the structural parameters are adjusted. If they do meet the requirements, the optimization design results are output.

[0065] This embodiment also provides an electronic device applicable to an optimization design method for a generator air cooler heat exchanger fin structure, comprising: a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions to realize the optimization design method for a generator air cooler heat exchanger fin structure as proposed in the above embodiment.

[0066] This embodiment also provides a storage medium storing a computer program that, when executed by a processor, implements an optimized design method for the heat exchanger structure of a generator air cooler as proposed in the above embodiments.

[0067] The storage medium proposed in this embodiment and the optimized design method for realizing the heat exchanger structure of a generator air cooler proposed in the above embodiment belong to the same inventive concept. Technical details not described in detail in this embodiment can be found in the above embodiments, and this embodiment has the same beneficial effects as the above embodiments.

[0068] Based on the above description of the implementation methods, those skilled in the art can clearly understand that the present invention can be implemented using software and necessary general-purpose hardware, and of course, it can also be implemented using hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk, or optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods of the various embodiments of the present invention.

[0069] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. An optimized design method for the heat exchange fin structure of a generator air cooler, characterized in that: include, Obtain the heat transfer performance requirements for the generator air cooler, including the target heat transfer coefficient and allowable flow pressure drop; In the three-dimensional model of the entire through-plate heat exchanger, a turbulence enhancement structure and a flow resistance optimization structure are set. The turbulence enhancement structure includes an initial turbulence section and a turbulence structure around the tube hole. The flow resistance optimization structure includes an opening structure distributed along the circumference of the tube hole. A computational fluid dynamics simulation model including the heat exchanger and cooling pipe is established, and the inlet velocity, inlet temperature and outlet pressure of the medium are set as boundary conditions. The flow field and heat transfer are solved by the simulation model to obtain the velocity field distribution, pressure field distribution and temperature field distribution when the medium flows through the heat exchange plate; The heat transfer coefficient of the heat exchange plate is calculated based on the velocity field distribution and the temperature field distribution, and the flow pressure drop of the medium flowing through the heat exchange plate is calculated based on the pressure field distribution. Determine whether the heat transfer coefficient reaches the target heat transfer coefficient and whether the flow pressure drop is less than the allowable flow pressure drop. If not, adjust the structural parameters of the turbulence enhancement structure and the structural parameters of the flow resistance optimization structure, and then re-solve the flow field and heat transfer. If the conditions are met, output the current structural parameters as the optimization design result.

2. The optimized design method for the heat exchanger fin structure of a generator air cooler as described in claim 1, characterized in that: The step of setting the turbulence enhancement structure and flow resistance optimization structure in the three-dimensional model of the entire plate heat exchanger includes determining the position of the medium inflow end on the heat exchanger and setting the initial turbulence section at the medium inflow end. Determine the position of the tube hole on the heat exchange plate, and set a flow-deflecting structure around the tube hole; Multiple openings are made on the heat exchange plate along the circumferential direction of the tube hole to form the flow resistance optimization structure.

3. The optimized design method for the heat exchanger fin structure of a generator air cooler as described in claim 2, characterized in that: The step of setting the initial turbulence section at the medium inflow end includes stamping a first protrusion structure at the medium inflow end of the heat exchange plate and setting the geometric dimension parameters of the first protrusion structure. The provision of a flow-disrupting structure around the pipe hole includes: A second protrusion structure is formed by stamping around the tube hole, and the geometric dimensional parameters of the second protrusion structure are set.

4. The optimized design method for the heat exchanger fin structure of a generator air cooler as described in claim 3, characterized in that: The step of opening multiple openings on the heat exchange plate along the circumferential direction of the tube hole includes determining the fan-shaped angle value of a single opening. Determine the number of openings to be made around the tube hole; The distribution position of each opening is determined in the circumferential direction of the tube hole based on the number of openings. Openings are punched on the heat exchange plate according to the stated sector angle value and the stated distribution position, and the edges of each opening are machined into an arc shape.

5. The optimized design method for the heat exchanger fin structure of a generator air cooler as described in claim 4, characterized in that: The step of establishing a computational fluid dynamics simulation model including the heat exchanger and the cooling pipe includes meshing the three-dimensional geometric model of the heat exchanger and the cooling pipe to generate a computational mesh. Select the turbulence model and set the fluid property parameters; The inner wall of the cooling pipe is set as a constant temperature wall, and the surface of the heat exchange plate is set as an insulating wall. Set the medium inlet as a velocity inlet, and input the inlet flow rate and inlet temperature of the medium; Set the medium outlet to a pressure outlet and enter the outlet pressure value.

6. The optimized design method for the heat exchanger fin structure of a generator air cooler as described in claim 5, characterized in that: The step of calculating the heat transfer coefficient of the heat exchanger based on the velocity field distribution and the temperature field distribution includes extracting the temperature values ​​of each node on the outer wall of the cooling pipe and the medium temperature values ​​of each node in the heat exchanger area. Calculate the temperature difference between the outer wall temperature of the cooling pipe and the temperature of the medium; Extract the heat flux density data of the outer wall surface of the cooling pipe; Dividing the heat flux density by the temperature difference yields the local heat transfer coefficient; The average heat transfer coefficient of the heat exchange plate is obtained by taking the area-weighted average of the local heat transfer coefficients of the outer wall of the cooling pipe.

7. The optimized design method for the heat exchanger fin structure of a generator air cooler as described in claim 6, characterized in that: The geometric parameters of the first protrusion structure include the protrusion height and tilt angle of the first protrusion structure; The geometrical parameters of the second protrusion structure include the protrusion height and the annular width of the second protrusion structure.

8. An optimization design system for the heat exchanger fin structure of a generator air cooler, employing the optimization design method for the heat exchanger fin structure of a generator air cooler as described in any one of claims 1 to 7, characterized in that, include: The parameter input module is used to receive the heat exchange performance requirements of the generator air cooler. The geometric modeling module is used to create a three-dimensional model of the entire through-plate heat exchanger, and to set up turbulence enhancement structures and flow resistance optimization structures in the three-dimensional model; The simulation model building module is used to build a computational fluid dynamics simulation model that includes the heat exchanger and cooling pipe; The flow field solution module is used to solve the flow field and heat transfer of the simulation model to obtain the velocity field distribution, pressure field distribution and temperature field distribution. The performance calculation module is used to calculate the heat transfer coefficient and flow pressure drop based on the velocity field distribution, the pressure field distribution, and the temperature field distribution. The optimization judgment module is used to determine whether the heat transfer coefficient and the flow pressure drop meet the heat transfer performance requirements. If they do not meet the requirements, the structural parameters are adjusted. If they do meet the requirements, the optimization design results are output.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the optimized design method for the heat exchanger structure of a generator air cooler according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the optimized design method for the heat exchanger structure of a generator air cooler according to any one of claims 1 to 7.

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