Method, medium and system for determining heat transfer factor of heat exchanger system

Abstract

The present invention discloses a method, medium, and system for determining the heat exchange factor of a heat exchanger system, comprising: inputting heat exchanger parameters and a first preset inlet air flow rate and temperature of the heat exchanger into HTRI software to output the heat exchanger's heat exchange capacity; fitting to obtain a heat exchange equation; establishing a three-dimensional model of the exchanger station in Fluent software; loading the heat exchange equation into Fluent software to simulate the heat exchange process of the heat exchanger, and outputting the inlet air temperature and flow rate of the heat exchanger under windy and windless conditions, respectively; inputting the inlet air temperature and flow rate of the heat exchanger under windy and windless conditions into the heat exchange equation to calculate the heat exchange capacity of the heat exchanger under windy and windless conditions, respectively; and dividing the sum of the heat exchange capacity of the heat exchanger under windy conditions by the sum of the heat exchange capacity of the heat exchanger under windless conditions to obtain the heat exchange factor. The present invention can efficiently and accurately calculate the heat exchange factor of a heat exchanger system.

Description

Technical Field

[0001] The present invention relates to the technical field of heat exchangers, and in particular to a method, medium and system for determining a heat transfer factor of a heat exchanger system. Background Art

[0002] The study focused on the air-cooled heat exchanger, the cooling system for the high-voltage converter transformers within a converter station. Each air-cooled heat exchanger has a fan at its back, generating negative pressure to draw in air from the outside environment. This airflow then flows through the heat exchange tube bundle, cooling the circulating oil entering the air-cooled heat exchanger. Because the cooling medium in an air-cooled heat exchanger is ambient air, its heat transfer performance is likely to fall below design values ​​during actual operation due to the influence of surrounding building envelopes and complex and variable weather conditions, impacting the safe operation of the converter station's high-voltage converter equipment. Therefore, using heat transfer factors allows analysis of the heat transfer performance of air-cooled heat exchangers under different wind conditions. The design values ​​for the heat transfer performance of the heat exchanger obtained from wind tunnel experiments do not match the actual heat transfer performance of the heat exchanger, impacting the safe operation of the high-voltage converter transformer. Summary of the Invention

[0003] Embodiments of the present invention provide a method, medium, and system for determining the heat transfer factor of a heat exchanger system to address the problem that, due to the influence of surrounding building envelopes and complex and changeable meteorological conditions, the design value of the heat transfer performance of the heat exchanger in the prior art cannot match the actual heat transfer performance of the actual heat exchanger, thereby affecting the safe operation of the high-voltage converter transformer.

[0004] In a first aspect, a method for determining a heat transfer factor of a heat exchanger system is provided, comprising:

[0005] Determining a wind environment condition of a heat exchanger station where the heat exchanger system is located according to a geographical location of the heat exchanger station where the heat exchanger system is located, wherein the heat exchanger system includes at least one heat exchanger;

[0006] Inputting the parameters of the heat exchanger, the first preset inlet air flow rate and the first preset inlet air temperature of the heat exchanger into the HTRI software, and outputting the heat exchange capacity of the heat exchanger;

[0007] The heat exchange equation is obtained by fitting according to a plurality of the first preset inlet air flow rates and the first preset inlet air temperatures and the corresponding heat exchange rates of the heat exchanger;

[0008] Based on the layout, actual building height, and building form of the converter station where the heat exchanger system is located, a three-dimensional model of the converter station is established in Fluent software, wherein the heat exchanger is simulated using a porous medium model;

[0009] After loading the heat exchange equation in the form of a user-defined function (UDF) in the Fluent software, the actual heat exchange process of each heat exchanger is simulated in the Fluent software using the three-dimensional model under the wind environment condition and the windless environment condition, and after stable heat exchange, the inlet air temperature and inlet air flow rate of each heat exchanger under the wind environment condition, and the inlet air temperature and inlet air flow rate of each heat exchanger under the windless environment condition are output respectively;

[0010] Substituting the output inlet temperature and inlet air flow of each heat exchanger under the windy environment condition and the windless environment condition into the heat exchange equation, respectively calculating the final heat exchange capacity of each heat exchanger under the windy environment condition and the windless environment condition;

[0011] The sum of the final heat exchange values ​​of each heat exchanger under the windy environment condition is divided by the sum of the final heat exchange values ​​of each heat exchanger under the windless environment condition to obtain the heat exchange factor of the heat exchanger system, so as to evaluate the heat exchange effect of the heat exchanger system according to the heat exchange factor.

[0012] In a second aspect, a computer-readable storage medium is provided, on which computer program instructions are stored; when the computer program instructions are executed by a processor, a method for determining the heat transfer factor of a heat exchanger system as described in the embodiment of the first aspect is implemented.

[0013] In a third aspect, a system for determining a heat transfer factor of a heat exchanger system is provided, comprising: a computer-readable storage medium as described in the embodiment of the second aspect above.

[0014] Thus, in this embodiment of the present invention, the heat exchanger selection software HTRI is combined with the numerical simulation software Fluent. Based on the established heat transfer equation, the heat transfer factor of the heat exchanger system under different wind environment conditions can be efficiently and accurately calculated. The heat transfer factor can be used to quantitatively evaluate the impact of local wind environment conditions on heat transfer capacity, thereby providing guidance for the initial design of the heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0016] Figure 1 is a flow chart of a method for determining a heat transfer factor of a heat exchanger system according to an embodiment of the present invention;

[0017] Figure 2is a schematic diagram of a heat exchanger system and surrounding buildings according to an embodiment of the present invention;

[0018] Figure 3 Schematic diagram of the calculation area established under windless environmental conditions;

[0019] Figure 4 Schematic diagram of the calculation area established under wind environment conditions. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments derived by ordinary technicians in this field based on the embodiments of the present invention without creative work are within the scope of protection of the present invention.

[0021] The present invention discloses a method for determining the heat transfer factor of a heat exchanger system. This method, based on highly operational numerical simulation technology, utilizes simulated pressure, temperature, and velocity cloud maps to more easily analyze and study factors influencing the heat exchanger's performance. Furthermore, compared to wind tunnel testing, numerical simulation can provide guidance during the initial design phase of a heat exchanger, enabling further optimization.

[0022] Specifically, such as Figure 1 As shown, the method includes the following steps:

[0023] Step S101: determining the wind environment conditions of the converter station where the heat exchanger system is located according to the geographical location of the converter station where the heat exchanger system is located.

[0024] The heat exchanger system includes at least one heat exchanger. When there are multiple heat exchangers, the multiple heat exchangers are identical heat exchangers. The heat exchangers are air-cooled heat exchangers.

[0025] Specifically, wind environment conditions include: average wind speed, wind direction, average outdoor temperature and average outdoor pressure.

[0026] Because extreme weather conditions are common in summer and winter, the average outdoor temperatures in these two seasons can be considered the upper and lower limits of the region's annual temperature, respectively. Therefore, when applying the aforementioned wind environment conditions, the wind environment conditions for summer and winter can be selected. The resulting heat transfer factor can be considered the upper and lower limits of the heat exchanger's heat transfer factor, allowing evaluation of heat transfer performance within the heat transfer factor's range. These parameters can be determined based on the outdoor meteorological parameters specified in the "Design Code for Heating, Ventilation, and Air Conditioning in Civil Buildings" and local meteorological data.

[0027] For example, for a converter station in a certain location, the summer wind environment conditions are: average wind speed of 3 m / s, southeast wind direction, average outdoor temperature of 40°C, and average outdoor pressure of 88,350 Pa. The winter wind environment conditions are: average wind speed of 3 m / s, northwest wind direction, average outdoor temperature of 10°C, and average outdoor pressure of 88,350 Pa.

[0028] Step S102: Input the parameters of the heat exchanger, the first preset inlet air flow rate and the first preset inlet air temperature of the heat exchanger into the HTRI software, and output the heat exchange capacity of the heat exchanger.

[0029] HTRI software is the HTRI Xchanger Suite, a heat exchanger selection software. Regarding heat exchanger calculations, HTRI is specialized in heat exchanger design, verification, and simulation. Relying on extensive experimental data and correlation formulas, HTRI accurately predicts heat transfer and pressure drop patterns for various heat exchangers, while remaining highly efficient and easy to use.

[0030] The heat exchanger of the embodiment of the present invention is a fin-type air-cooled heat exchanger, which is composed of aluminum base tube channels and corrugated aluminum fins. The transformer cooling oil exchanges heat with the air when passing through the tube bundle channel, and the pipe transfers heat to the aluminum fins.

[0031] The heat exchanger parameters include: the length, width, and height of the heat exchanger; the number of finned tube rows; the number of finned tubes in each row; the material, length, outer diameter, and center-to-center distance of the base tubes; the number of fins per unit length of the base tube; the material, nominal thickness, thickness, and fin root diameter of the fins; and the diameter of the fan. It should be understood that in this embodiment of the present invention, one fan is configured for each heat exchanger.

[0032] For example, a heat exchanger has a length of 5.7 meters, a height of 1.7 meters, and a width of 0.3 meters. There are 6 rows of finned tubes, with 39 fins per row. The base tube is made of S30409, is 5.6 meters long, has an outer diameter of 16.7 mm, and a center-to-center distance of 38 mm. The number of fins per unit length of base tube is 433. The fins are made of aluminum, with a nominal thickness of 0.8 mm, a thickness of 0.1 mm, and a fin root diameter of 16.8 mm. The fan has a diameter of 0.945 meters.

[0033] The first preset inlet air flow rate and the first preset inlet air temperature of the heat exchanger can be selected according to actual conditions. These parameters are selected so that the error of the final result is small, for example, less than 5%.

[0034] Among them, the inlet oil temperature is 50℃ and the inlet oil flow rate is 14.83kg·s -1 .

[0035] In a specific embodiment, the first preset inlet air flow rate, the first preset inlet air temperature, and the heat exchange capacity of the heat exchanger output by the HTRI software are shown in Table 1.

[0036] Table 1 The first preset inlet air flow rate, the first preset inlet air temperature and the heat exchange rate

[0037]

[0038] Step S103: obtaining a heat exchange equation by fitting according to a plurality of first preset inlet air flow rates and first preset inlet air temperatures and corresponding heat exchange capacities of the heat exchangers.

[0039] The heat exchange equation of the embodiment of the present invention can be obtained by fitting the above data, which is as follows:

[0040] Q = a 00 +a 10 t in +a 01 G+a 20 t in 2 +a 11 t in G+a 02 G 2 .

[0041] Where Q represents the heat transfer amount, G represents the inlet air flow rate of the heat exchanger, and t in Indicates the inlet air temperature of the heat exchanger, a 00 、a 10 、a 01 、a 20 、a 11 、a 02 They represent constant terms respectively. Through fitting, the heat transfer equation for the heat exchanger in the above specific embodiment is obtained as follows:

[0042]

[0043] Since the heat exchangers in the embodiments of the present invention are all the same, the heat transfer equation of each heat exchanger is the same.

[0044] Step S104: Based on the layout, actual building height, and building form of the converter station where the heat exchanger system is located, a three-dimensional model of the converter station is created in Fluent software.

[0045] The numerical simulation software Fluent is currently the most widely used and technologically mature commercial simulation software in the world, so I will not go into details here.

[0046] For example, the heat exchanger station where the heat exchanger system is located is located in a certain place. The overall layout of the heat exchanger system and its surrounding buildings, the actual height of the buildings and the building form are as follows: Figure 2 As shown. The converter station where the heat exchanger system is located contains two sets of converter transformer systems with the same specifications, namely pole 1 converter transformer and pole 2 converter transformer. Each pole converter transformer has six high-voltage transformers, and each transformer requires a set of heat exchange equipment to cool it. The heat exchange equipment of each transformer is composed of four heat exchangers arranged vertically in parallel. Each set of heat exchangers is equipped with four induced draft fans for forced heat exchange. The indoor DC field and valve hall of each pole are 26m high, and the control building located between the pole 1 valve hall and the pole 2 valve hall is 16m high. In specific applications, the general plan of the converter station can be drawn according to the relevant actual values ​​of the converter station, and the general plan can be input into the Fluent software to set the height of the corresponding building.

[0047] In addition, the heat exchanger is simulated using a porous media model. The porous media resistance coefficient includes the inertial resistance coefficient and the viscous resistance coefficient. These coefficients can be pre-fitted using a parameter table of the heat exchanger tube bundle pressure drop at different inlet flow rates. The specific acquisition method is as follows:

[0048] (1) The heat exchanger parameters, the second preset inlet air flow rate, the second preset inlet air temperature, the inlet oil temperature of 50 ° C and 14.83 kg·s -1 The standard inlet oil flow is input into the HTRI software, and the pressure drop of the output air after passing through the heat exchanger tube bundle is obtained.

[0049] The parameters of the heat exchanger are as described above and will not be repeated here. The second preset inlet air flow rate can be selected according to the actual situation. The selected parameters make the final result error smaller, for example, less than 5%. The second preset inlet air temperature is 25°C, the inlet oil temperature is 50°C, and the standard inlet oil flow rate is 14.83 kg·s -1 .

[0050] (2) According to a plurality of second preset inlet air flow rates and the corresponding pressure drops of the air after passing through the heat exchanger tube bundle, a pressure drop equation is obtained by fitting.

[0051] The second preset inlet air flow rates and the corresponding pressure drops of the air after passing through the heat exchanger tube bundle are shown in Table 2.

[0052] Table 2 Second preset inlet air flow and pressure drop

[0053] <![CDATA[Inlet air flow rate G (m 3 / s)]]> 15 20 25 30 35 Pressure drop of cold air passing through the tube bundle ΔP (Pa) 10.07 16.14 23.32 31.56 40.79

[0054] Specifically, the pressure drop equation obtained by fitting the data in Table 2 is as follows:

[0055]

[0056] Among them, c0 and c1 are the first parameter and the second parameter respectively; G is the inlet air flow, m 3 / s; A is the windward area of ​​the heat exchanger tube bundle, m 2 ; ΔP is the pressure drop after the air passes through the converter tube bundle, Pa.

[0057] (3) According to the first parameter and the second parameter in the pressure drop equation obtained by fitting, the inertial drag coefficient and the viscous drag coefficient are calculated respectively.

[0058] Among them, the inertial resistance coefficient is:

[0059] The viscous drag coefficient is:

[0060] Where ρ is the air density, kg / m 3 ; μ is the dynamic viscosity, kg / (m·s); Δn is the thickness of the porous medium region, m.

[0061] These two parameters are set in Fluent software when building a three-dimensional model.

[0062] In a specific embodiment, the inertial drag coefficient and the viscous drag coefficient are 13.9917m -1 and 567963m -2 .

[0063] Step S105: After loading the heat exchange equation in the form of a user-defined function (UDF) in the Fluent software, the actual heat exchange process of each heat exchanger is simulated in the Fluent software through a three-dimensional model under wind environment conditions and no wind environment conditions. After stable heat exchange, the inlet air temperature and inlet air flow of each heat exchanger under wind environment conditions, as well as the inlet air temperature and inlet air flow of each heat exchanger under no wind environment conditions, are output respectively.

[0064] Specifically, this step includes the following process:

[0065] (1) Determine the calculation area in Fluent software based on the three-dimensional model.

[0066] Specifically, the calculation area meets the following requirements:

[0067] The area of ​​the heat exchanger system is less than 3% of the area of ​​the calculation area. The horizontal calculation area is the area within a preset radius centered on the heat exchanger system area. The height of the calculation area above the heat exchanger is the preset height. The preset radius is the product of the heat exchanger height and the first multiple, and the preset height is greater than the product of the heat exchanger height and the second multiple. For example, if the heat exchanger height is H, the first multiple can be 5 and the second multiple can be 3.

[0068] In a specific embodiment, the length, width and height of the calculation area are respectively 1000m, 1000m and 150m. Figure 3 and 4 The cube shown.

[0069] (2) Set the boundary conditions of the calculation area according to the wind environment conditions and the no-wind environment conditions respectively.

[0070] Boundary conditions include wall, inlet, and outlet conditions. When setting boundary conditions in Fluent, except for the specific condition parameters described below, all other settings can be left as default. For example, the default values ​​for wall slip and roughness can be used for wall boundary conditions.

[0071] Specifically, for the inlet boundary conditions:

[0072] ① Under wind environment conditions, the wind direction surface adopts the velocity inlet boundary condition. For the specific ambient incoming wind speed, the power exponential wind speed profile formula is used to represent the distribution law of the ambient wind speed near the ground. The formula is as follows:

[0073] ν i =ν(z i / z0) a .

[0074] Among them, ν i Indicates the distance from the ground z i The wind speed is in meters, ν represents the wind speed at the measuring point, that is, the aforementioned average wind speed, which is set to 3 m / s, z0 represents the height of the measuring point, and α represents the ground roughness.

[0075] ② Under windless environmental conditions, select the pressure inlet boundary, that is, the outdoor average temperature and outdoor average pressure are constant.

[0076] Regardless of windy or no-wind environmental conditions, the outlet boundary condition adopts the pressure outlet boundary, that is, the outdoor average temperature and outdoor average pressure are constant.

[0077] (3) After the heat transfer equation is loaded in the form of a user-defined function (UDF) in the Fluent software, the actual heat transfer process of each heat exchanger is simulated through a three-dimensional model under wind environment conditions and no wind environment conditions, as well as the boundary conditions of the corresponding calculation area. After stable heat exchange, the inlet air temperature and inlet air flow of each heat exchanger under wind environment conditions, as well as the inlet air temperature and inlet air flow of each heat exchanger under no wind environment conditions, are output respectively.

[0078] During the simulation, the following conditions need to be set:

[0079] The heat exchanger parameters remain constant, that is, they are not affected by changes in ambient wind conditions; air is an ideal gas, and its physical parameters are constant; the thermophysical properties of the heat exchanger remain constant; when the airflow passes through the porous medium part of the fin, only heat conduction and heat convection are considered, that is, radiation heat transfer in the medium is not considered.

[0080] Specifically, you can write a user-defined function (UDF) and use the DEFINE_ADJUST function to obtain the inlet air temperature t of the heat exchanger. in and the inlet air flow G; use the DEFINE_SOURCE function through the equation Q(t in ,G) Calculate the heat exchange amount Q corresponding to the inlet air temperature and inlet air flow of the heat exchanger in each iteration, and load the heat to the corresponding porous medium area until the iteration is balanced, and output the corresponding inlet air temperature and inlet volume flow of the heat exchanger.

[0081] Step S106: Substitute the output inlet air temperature and inlet air flow of each heat exchanger under windy environment conditions and windless environment conditions into the heat exchange equation, and calculate the final heat exchange of each heat exchanger under windy environment conditions and windless environment conditions.

[0082] For example, the inlet air temperature and inlet air flow rate are substituted into the following equation to calculate the final heat transfer capacity of the heat exchanger under the corresponding conditions.

[0083]

[0084] Step S107: Divide the sum of the final heat exchange amounts of each heat exchanger under windy conditions by the sum of the final heat exchange amounts of each heat exchanger under no-wind conditions to obtain a heat exchange factor of the heat exchanger system, so as to evaluate the heat exchange effect of the heat exchanger system according to the heat exchange factor.

[0085] Specifically, the following formula is used for calculation:

[0086]

[0087] Where J represents the heat transfer factor, represents the final heat transfer capacity of heat exchanger i under wind environment conditions, It represents the final heat transfer capacity of heat exchanger i under windless environment conditions.

[0088] Since there are two wind environment conditions in summer and winter, the upper and lower limits of the heat transfer factor can be obtained respectively, so as to better evaluate the heat transfer effect.

[0089] Through the above process, the heat exchanger selection software HTRI is combined with the numerical simulation software Fluent. Based on the established heat transfer equation of the heat exchanger, the heat transfer law of the heat exchanger under different environments obtained from the selection software HTRI is loaded into the simulation software Fluent through a user-defined function (UDF). The porous medium model is used to simplify the fin part of the air-cooled heat exchanger, thereby simplifying the process for relevant researchers to conduct simulation research on such problems. In addition, the numerical simulation method can efficiently and accurately simulate the heat transfer performance of the air-cooled heat exchanger under different environmental conditions, thereby providing guidance for the initial design of the air-cooled heat exchanger.

[0090] An embodiment of the present invention further discloses a computer-readable storage medium having computer program instructions stored thereon; when the computer program instructions are executed by a processor, the method for determining the heat transfer factor of the heat exchanger system as described in the above embodiment is implemented.

[0091] An embodiment of the present invention further discloses a system for determining a heat transfer factor of a heat exchanger system, comprising: a computer-readable storage medium as described in the above embodiment.

[0092] In summary, the embodiments of the present invention combine the heat exchanger selection software HTRI with the numerical simulation software Fluent. Based on the established heat transfer equation, the heat transfer factor of the heat exchanger system under different wind environment conditions can be efficiently and accurately calculated. The heat transfer factor can be used to quantitatively evaluate the impact of local wind environment conditions on heat transfer capacity, thereby providing guidance for the initial design of the heat exchanger.

[0093] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A method for determining the heat transfer factor of a heat exchanger system, characterized in that: include: Determining a wind environment condition of a heat exchanger station where the heat exchanger system is located according to a geographical location of the heat exchanger station where the heat exchanger system is located, wherein the heat exchanger system includes at least one heat exchanger; Inputting the parameters of the heat exchanger, the first preset inlet air flow rate and the first preset inlet air temperature of the heat exchanger into the HTRI software, and outputting the heat exchange capacity of the heat exchanger; A heat exchange equation is obtained by fitting according to a plurality of the first preset inlet air flow rates and the first preset inlet air temperatures and the corresponding heat exchange rates of the heat exchanger; Based on the layout, actual building height, and building form of the converter station where the heat exchanger system is located, a three-dimensional model of the converter station is established in Fluent software, wherein the heat exchanger is simulated using a porous medium model; After loading the heat exchange equation in the form of a user-defined function (UDF) in the Fluent software, the actual heat exchange process of each heat exchanger is simulated in the Fluent software using the three-dimensional model under the wind environment condition and the windless environment condition, and after stable heat exchange, the inlet air temperature and inlet air flow rate of each heat exchanger under the wind environment condition, and the inlet air temperature and inlet air flow rate of each heat exchanger under the windless environment condition, are output respectively; Substituting the output inlet air temperature and inlet air flow of each heat exchanger under the windy environment condition and the windless environment condition into the heat exchange equation, respectively, to calculate the final heat exchange of each heat exchanger under the windy environment condition and the windless environment condition; The sum of the final heat exchange values ​​of each heat exchanger under the windy environment condition is divided by the sum of the final heat exchange values ​​of each heat exchanger under the windless environment condition to obtain the heat exchange factor of the heat exchanger system, so as to evaluate the heat exchange effect of the heat exchanger system according to the heat exchange factor.

2. The method for determining the heat transfer factor of a heat exchanger system according to claim 1, characterized in that: The heat transfer equation is: Q=a 00 +a 10 t in +a 01 G+a 20 t in 2 +a 11 t in G+a 02 G 2 , Where Q represents the heat transfer amount, G represents the inlet air flow rate of the heat exchanger, and t in Indicates the inlet air temperature of the heat exchanger, a 00 、a 10 、a 01 、a 20 、a 11 、a 02 represent constant terms respectively.

3. The method for determining the heat transfer factor of a heat exchanger system according to claim 1, wherein: The step of simulating the actual heat exchange process of each heat exchanger by using the three-dimensional model in the Fluent software includes: Determining a calculation area in the Fluent software based on the three-dimensional model; Setting boundary conditions of the calculation area according to the wind environment condition and the no-wind environment condition respectively, wherein the boundary conditions include: wall boundary conditions, inlet boundary conditions and outlet boundary conditions; After loading the heat transfer equation in the form of a user-defined function (UDF) in the Fluent software, the actual heat exchange process of each heat exchanger is simulated through the three-dimensional model under the wind environment condition and the no-wind environment condition, as well as the boundary conditions of the corresponding calculation area. After stable heat exchange, the inlet air temperature and the inlet air flow of each heat exchanger under the wind environment condition, as well as the inlet air temperature and the inlet air flow of each heat exchanger under the no-wind environment condition, are output respectively.

4. The method for determining the heat transfer factor of a heat exchanger system according to claim 1, characterized in that: The method for obtaining the inertial resistance coefficient and the viscous resistance coefficient of the porous medium model includes: The parameters of the heat exchanger, the second preset inlet air flow rate, the second preset inlet air temperature, the 50°C inlet oil temperature and the 14.83 kg·s -1 The standard inlet oil flow is input into the HTRI software, and the pressure drop of the output air after passing through the heat exchanger tube bundle is obtained; According to the plurality of second preset inlet air flow rates and the corresponding pressure drops of the air after passing through the heat exchanger tube bundle, a pressure drop equation is obtained by fitting, wherein the pressure drop equation is: c0 and c1 are the first and second parameters respectively, G is the inlet air flow rate, A is the windward area of ​​the heat exchanger tube bundle, and ΔP is the pressure drop after the air passes through the heat exchanger tube bundle; According to the first parameter and the second parameter in the pressure drop equation obtained by fitting, the inertial resistance coefficient and the viscous resistance coefficient are calculated respectively, wherein the inertial resistance coefficient D i The calculation equation is: The viscous drag coefficient C i The calculation equation is: ρ is the air density, μ is the dynamic viscosity, and Δn is the thickness of the porous medium region.

5. The method for determining the heat transfer factor of a heat exchanger system according to claim 1, characterized in that: The wind environment conditions include: average wind speed, wind direction, average outdoor temperature and average outdoor pressure.

6. The method for determining the heat transfer factor of a heat exchanger system according to claim 1, characterized in that: The parameters of the heat exchanger include: the length, width and height of the heat exchanger, the number of rows of finned tubes, the number of finned tubes in each row, the material, length, outer diameter and tube center distance of the base tube of the finned tube, the number of fins per unit length of the base tube, the material, nominal thickness, thickness and fin root diameter of the fins, and the fan diameter.

7. The method for determining the heat transfer factor of a heat exchanger system according to claim 3, characterized in that: The calculation area meets the following requirements: The area of ​​the heat exchanger system area is less than 3% of the area of ​​the calculation area. The horizontal calculation area is the area within a preset radius centered on the heat exchanger system area. The height of the calculation area above the heat exchanger system is a preset height, wherein the preset radius is the product of the heat exchanger height and the first multiple, and the preset height is greater than the product of the heat exchanger height and the second multiple.

8. The method for determining the heat transfer factor of a heat exchanger according to claim 3, wherein: During the simulation, the following conditions are set: The heat exchanger parameters remain constant; air is an ideal gas, and its physical parameters are constant; the thermophysical properties of the heat exchanger remain constant; when the airflow passes through the porous medium part of the fin, only heat conduction and heat convection are considered.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer program instructions; when the computer program instructions are executed by a processor, the method for determining the heat exchange factor of the heat exchanger system according to any one of claims 1 to 8 is implemented.

10. A system for determining a heat transfer factor of a heat exchanger system, characterized in that: include: The computer-readable storage medium of claim 9.

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