Method, device and equipment for calculating heat transfer coefficient of railway vehicle and medium

Abstract

The invention provides a calculation method, device and equipment for a heat transfer coefficient of a railway vehicle and a medium, and the method comprises the steps: for each structure model in a thermal resistance model of the railway vehicle, calculating a plurality of heat transfer layer thermal resistance values corresponding to the structure model, and calculating a structure thermal resistance value of the structure model based on the plurality of heat transfer layer thermal resistance values; for each area model, calculating the area thermal resistance value of the area model based on the structure thermal resistance values of the plurality of structure models corresponding to the area model; and calculating the total thermal resistance value of the rail vehicle based on the regional thermal resistance value of each regional model, and calculating the heat transfer coefficient of the rail vehicle based on the total thermal resistance value. By means of the method and device, the efficiency and accuracy of calculating the heat transfer coefficient of the railway vehicle are improved, and the research and development period can be shortened.

Description

Technical Field

[0001] The present application relates to the technical field of rail vehicles, and in particular to a method, device, equipment and medium for calculating a heat transfer coefficient of a rail vehicle. Background Art

[0002] The heat transfer coefficient K value of rail vehicles reflects the quality of thermal insulation performance. It is numerically equal to the amount of heat transferred through the insulation wall per unit area per unit time, and is an important parameter in the field of rail vehicle air conditioning. In the design stage of the layout of insulation materials for rail vehicles, the calculation of K value by simulation analysis method has been widely used. Since the heat transfer process of rail vehicles is essentially three-dimensional, and there are many cold bridges and cavities in the enclosure structure in addition to the car body, insulation materials, and wall panels, this brings difficulties to the three-dimensional calculation of K value. Therefore, simplified two-dimensional section simulation or three-dimensional simulation of typical components is the current main simulation analysis idea.

[0003] However, the simulation analysis work based on the above ideas inevitably requires geometric cleaning, meshing, model building and result output, which takes a long time. Therefore, how to quickly calculate the heat transfer coefficient K value of rail vehicles to achieve one-click output of the K value has become a technical problem that cannot be underestimated. Summary of the invention

[0004] In view of this, the purpose of the present application is to provide a method, device, equipment and medium for calculating the heat transfer coefficient of a rail vehicle. By constructing a thermal resistance model of a rail vehicle, modeling and result output can be conveniently and intuitively performed, thereby improving the efficiency and accuracy of calculating the heat transfer coefficient of a rail vehicle, and helping to save and shorten the research and development cycle.

[0005] In a first aspect, an embodiment of the present application provides a method for calculating a heat transfer coefficient of a rail vehicle, the method comprising:

[0006] Establishing a thermal resistance model of a rail vehicle; wherein the thermal resistance model includes a plurality of regional models of the enclosure structure of the rail vehicle, each regional model includes a plurality of structural models, and each structural model includes a plurality of heat transfer layer models;

[0007] For each structural model, multiple heat transfer layer thermal resistance values ​​corresponding to the structural model are calculated, and the structural thermal resistance value of the structural model is calculated based on the multiple heat transfer layer thermal resistance values; wherein each heat transfer layer model in the structural model corresponds to a different thermal layer thermal resistance value;

[0008] For each regional model, a regional thermal resistance value of the regional model is calculated based on the structural thermal resistance values ​​of multiple structural models corresponding to the regional model;

[0009] A total thermal resistance value of the rail vehicle is calculated based on the regional thermal resistance value of each regional model, and a heat transfer coefficient of the rail vehicle is calculated based on the total thermal resistance value.

[0010] Furthermore, the thermal resistance values ​​of the multiple heat transfer layers include a first convective heat transfer resistance between the air inside the vehicle and the inner wall of the vehicle, a second convective heat transfer resistance between the air outside the vehicle and the outer wall of the vehicle, the thermal resistance of the body profile, the first thermal resistance of the insulation material in the heat transfer direction, and the simplified thermal resistance in the heat transfer direction.

[0011] Furthermore, the first convective heat transfer resistance and the second convective heat transfer resistance are calculated by the following steps:

[0012] Determining a natural convection surface heat transfer coefficient between the interior air of the rail vehicle and an inner wall of the vehicle, and calculating the first convection heat transfer thermal resistance based on the natural convection surface heat transfer coefficient and a heat transfer area;

[0013] A forced convection surface heat transfer coefficient between the air outside the rail vehicle and an outer wall of the vehicle is determined, and the second convection heat transfer thermal resistance is calculated based on the forced convection surface heat transfer coefficient and the heat transfer area.

[0014] Furthermore, the thermal resistance of the vehicle body profile is calculated by the following steps:

[0015] Determining the thermal conductivity corresponding to the body profile material of the rail vehicle;

[0016] The body profile thermal resistance is calculated based on the thermal conductivity, the actual thickness of the body profile material of the rail vehicle, and the heat transfer area.

[0017] Furthermore, the first thermal resistance of the insulation material in the heat transfer direction is calculated by the following steps:

[0018] The second thermal resistance per unit area of ​​a single layer of thermal insulation material is calculated based on the thermal conductivity corresponding to the thermal insulation material of the rail vehicle and the actual thickness of the thermal insulation material, and the sum of all second thermal resistances is used as the first thermal resistance of the thermal insulation material in the heat transfer direction.

[0019] Furthermore, the simplified thermal resistance in the heat transfer direction is calculated by the following steps:

[0020] Acquiring heat transfer coefficient test values ​​of a plurality of test vehicles, and calculating a thermal resistance test value of each test vehicle based on the heat transfer coefficient test value of each test vehicle;

[0021] Determining a simplified thermal resistance preset value, and calculating a thermal resistance calculated value of each test vehicle based on the simplified thermal resistance preset value and a heat transfer coefficient test value of each test vehicle;

[0022] determining an average deviation based on the thermal resistance test value and the thermal resistance calculated value of each test vehicle, and calculating a correction factor based on the average deviation;

[0023] The simplified thermal resistance preset value is corrected based on the correction coefficient to obtain the simplified thermal resistance.

[0024] In a second aspect, an embodiment of the present application further provides a device for calculating a heat transfer coefficient of a rail vehicle, the device comprising:

[0025] A thermal resistance model building module is used to build a thermal resistance model of a rail vehicle; wherein the thermal resistance model includes a plurality of regional models of the enclosure structure of the rail vehicle, each regional model includes a plurality of structural models, and each structural model includes a plurality of heat transfer layer models;

[0026] A structural thermal resistance value calculation module is used to calculate, for each structural model, a plurality of thermal resistance values ​​of heat transfer layers corresponding to the structural model, and calculate the structural thermal resistance value of the structural model based on the plurality of thermal resistance values ​​of the heat transfer layers; wherein each heat transfer layer model in the structural model corresponds to a different thermal resistance value of the heat layer;

[0027] A regional thermal resistance value calculation module, used for calculating the regional thermal resistance value of each regional model based on the structural thermal resistance values ​​of multiple structural models corresponding to the regional model;

[0028] The heat transfer coefficient calculation module is used to calculate the total thermal resistance value of the rail vehicle based on the regional thermal resistance value of each regional model, and calculate the heat transfer coefficient of the rail vehicle based on the total thermal resistance value.

[0029] Furthermore, the thermal resistance values ​​of the multiple heat transfer layers include a first convective heat transfer resistance between the air inside the vehicle and the inner wall of the vehicle, a second convective heat transfer resistance between the air outside the vehicle and the outer wall of the vehicle, the thermal resistance of the body profile, the first thermal resistance of the insulation material in the heat transfer direction, and the simplified thermal resistance in the heat transfer direction.

[0030] In a third aspect, an embodiment of the present application further provides an electronic device, comprising: a processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the electronic device is running, the processor communicates with the memory through the bus, and when the machine-readable instructions are executed by the processor, the steps of the method for calculating the heat transfer coefficient of a rail vehicle as described above are performed.

[0031] In a fourth aspect, an embodiment of the present application further provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of the method for calculating the heat transfer coefficient of a rail vehicle as described above are executed.

[0032] A method, device, equipment and medium for calculating the heat transfer coefficient of a rail vehicle provided in an embodiment of the present application, first, a thermal resistance model of a rail vehicle is established; wherein the thermal resistance model includes multiple regional models of the enclosure structure of the rail vehicle, each regional model includes multiple structural models, and each structural model includes multiple heat transfer layer models; then, for each structural model, multiple heat transfer layer thermal resistance values ​​corresponding to the structural model are calculated, and the structural thermal resistance value of the structural model is calculated based on the multiple heat transfer layer thermal resistance values; wherein each heat transfer layer model in the structural model corresponds to a different thermal layer thermal resistance value; for each regional model, the regional thermal resistance value of the regional model is calculated based on the structural thermal resistance values ​​of the multiple structural models corresponding to the regional model; finally, the total thermal resistance value of the rail vehicle is calculated based on the regional thermal resistance value of each regional model, and the heat transfer coefficient of the rail vehicle is calculated based on the total thermal resistance value.

[0033] By constructing a thermal resistance model of a rail vehicle, this application can conveniently and intuitively perform modeling and output results, which greatly reduces the time consumption compared to conventional simulation analysis of the K value, improves the efficiency and accuracy of calculating the heat transfer coefficient of the rail vehicle, and has obvious practical value in the design or rapid verification of the layout of thermal insulation materials for rail vehicles, which is conducive to saving project development costs and shortening the R&D cycle.

[0034] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 A flow chart of a method for calculating a heat transfer coefficient of a rail vehicle provided in an embodiment of the present application;

[0037] Figure 2 A schematic diagram of a thermal resistance model of a rail vehicle provided in an embodiment of the present application;

[0038] Figure 3 A schematic diagram of the structure of a device for calculating the heat transfer coefficient of a rail vehicle provided in an embodiment of the present application;

[0039] Figure 4 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0040] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application usually described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, each other embodiment obtained by those skilled in the art without making creative work belongs to the scope of protection of the present application.

[0041] First, the application scenarios to which the present application is applicable are introduced. The present application can be applied in the field of rail vehicle technology.

[0042] The heat transfer coefficient K value of rail vehicles reflects the quality of thermal insulation performance. It is numerically equal to the amount of heat transferred through the insulation wall per unit area per unit time, and is an important parameter in the field of rail vehicle air conditioning. In the design stage of the layout of insulation materials for rail vehicles, the calculation of K value by simulation analysis method has been widely used. Since the heat transfer process of rail vehicles is essentially three-dimensional, and there are many cold bridges and cavities in the enclosure structure in addition to the car body, insulation materials, and wall panels, this brings difficulties to the three-dimensional calculation of K value. Therefore, simplified two-dimensional section simulation or three-dimensional simulation of typical components is the current main simulation analysis idea.

[0043] However, research has found that the simulation analysis based on the above ideas inevitably requires geometric cleaning, meshing, model building and result output, which takes a long time. Therefore, how to quickly calculate the heat transfer coefficient K value of rail vehicles to achieve one-click output of the K value has become a technical problem that cannot be underestimated.

[0044] Based on this, an embodiment of the present application provides a method for calculating the heat transfer coefficient of a rail vehicle. By constructing a thermal resistance model of a rail vehicle, modeling and result output can be conveniently and intuitively performed, thereby improving the efficiency and accuracy of calculating the heat transfer coefficient of a rail vehicle, and helping to save and shorten the R&D cycle.

[0045] See also Figure 1 , Figure 1 A flow chart of a method for calculating the heat transfer coefficient of a rail vehicle provided in an embodiment of the present application. Figure 1 As shown in , the calculation method provided in the embodiment of the present application includes:

[0046] S101, establishing a thermal resistance model of a rail vehicle.

[0047] For the above step S101, during the specific implementation, a thermal resistance model of the rail vehicle is established. Specifically, according to the embodiment provided by the present application, the thermal resistance model of the rail vehicle includes multiple regional models of the enclosure structure of the rail vehicle, each regional model includes multiple structural models, and each structural model includes multiple heat transfer layer models.

[0048] See also Figure 2 , Figure 2 A schematic diagram of a thermal resistance model of a rail vehicle provided in an embodiment of the present application. Figure 2 As shown, T ext represents the outside temperature of the rail vehicle, T int represents the interior temperature of the rail vehicle, Figure 2 (A) is the thermal resistance model of the rail vehicle. The enclosure structure of the rail vehicle can be divided into four typical regions: top, side, bottom and end according to the orientation, that is, a four-region model is constructed. Figure 2 (B) is a regional model, and its thermal resistance R i There is a parallel relationship between them. Each typical area can be divided into multiple typical structures, that is, multiple structural models. Figure 2 (C) is the structural model, and its thermal resistance R ij There is also a parallel relationship between them. Each typical structure has multiple heat transfer layers in the heat transfer direction, that is, multiple heat transfer layer models, and its thermal resistance R ijk There is a series relationship between them.

[0049] S102, for each structural model, calculating a plurality of thermal resistance values ​​of heat transfer layers corresponding to the structural model, and calculating a structural thermal resistance value of the structural model based on the plurality of thermal resistance values ​​of the heat transfer layers.

[0050] For the above step S102, for each structural model, the thermal resistance values ​​of multiple heat transfer layers corresponding to the structural model are calculated. Each heat transfer layer model in the structural model corresponds to a different thermal resistance value of the heat layer. Then, the structural thermal resistance value of the structural model is calculated based on the thermal resistance values ​​of the multiple heat transfer layers. Here, since the thermal resistance of each heat transfer layer is in series, the sum of the thermal resistance values ​​of the multiple heat transfer layers is the structural thermal resistance value of the structural model.

[0051] Here, according to the embodiment provided by the present application, a typical structure is decomposed into heat transfer layers, and the thermal resistance values ​​of the multiple heat transfer layers include the first convection heat transfer resistance R between the air inside the vehicle and the inner wall of the vehicle. ij1 , the second convection heat transfer resistance R between the outside air and the vehicle outer wall ij5 、Car body profile thermal resistance R ij4 , the first thermal resistance R of the insulation material in the heat transfer direction ij3 And the simplified thermal resistance R in the heat transfer direction ij2 Here the simplified thermal resistance Rij2 Refers to the heat transfer direction in addition to the first thermal resistance R ij3 The equivalent thermal resistance outside is called simplified thermal resistance. Furthermore, the structural thermal resistance value of the structural model to which the heat transfer layer model belongs is R ij =R ij1 +R ij2 +R ij3 +R ij4 +R ij5 .

[0052] Specifically, during the test of the thermal insulation performance of rail vehicles, the air outside the vehicle is driven by a high-power fan at a high speed, so the heat transfer between the air outside the vehicle and the outer wall of the vehicle is forced convection; while near the inner wall of the vehicle, the movement of the air inside the vehicle is mainly driven by the density difference caused by the change in air temperature, and the air flow rate is small, so the heat transfer between the air inside the vehicle and the inner wall of the vehicle is natural convection. According to the range of forced convection surface heat transfer coefficient and natural convection surface heat transfer coefficient, R is determined. ij1 , R ij5 Specifically, according to the embodiment provided in the present application, the first convective heat transfer resistance R is calculated by the following steps: ij1 And the second convection heat transfer resistance R ij5 :

[0053] The natural convection surface heat transfer coefficient between the interior air of the rail vehicle and the vehicle inner wall is determined, and the first convection heat transfer thermal resistance is calculated based on the natural convection surface heat transfer coefficient and the heat transfer area.

[0054] In the specific implementation of the above steps, the natural convection surface heat transfer coefficient between the air inside the rail vehicle and the inner wall of the vehicle is first determined. Specifically, the natural convection surface heat transfer coefficient is usually within the following range: Air: 0.5W / m 2 K to 10W / m 2 K. Then the first convection heat transfer resistance R is calculated based on the natural convection surface heat transfer coefficient and the heat transfer area ij1 Here, the first convection heat transfer resistance is the inverse of the product of the natural convection surface heat transfer coefficient and the heat transfer area.

[0055] A forced convection surface heat transfer coefficient between the air outside the rail vehicle and an outer wall of the vehicle is determined, and the second convection heat transfer thermal resistance is calculated based on the forced convection surface heat transfer coefficient and the heat transfer area.

[0056] In the above steps, when implementing the above steps, the forced convection surface heat transfer coefficient between the outside air of the rail vehicle and the outer wall of the vehicle is first determined. Specifically, the forced convection surface heat transfer coefficient is usually in the following range: air: 10W / m 2 K to 100W / m 2K. Then the second convection heat transfer resistance R is calculated based on the forced convection surface heat transfer coefficient and the heat transfer area ij5 Here, the second convection heat transfer resistance R ij5 It is the reciprocal of the product of the forced convection surface heat transfer coefficient and the heat transfer area.

[0057] Specifically, since the body of a rail vehicle is a profile cavity structure, the thermal conductivity of different materials varies greatly. It is necessary to calculate the thermal resistance R of the body profile corresponding to different materials based on the thermal conductivity corresponding to the body materials of different materials. ij4 Specifically, according to the embodiment provided in the present application, the thermal resistance of the vehicle body profile is calculated by the following steps:

[0058] Determine the thermal conductivity corresponding to the body profile material of the rail vehicle; and calculate the body profile thermal resistance based on the thermal conductivity, the actual thickness of the body profile material of the rail vehicle, and the heat transfer area.

[0059] For the above two steps, in the specific implementation, the thermal conductivity k corresponding to the body profile material of the rail vehicle is first determined. Then, based on the thermal conductivity k, the actual thickness L of the body profile material of the rail vehicle and the heat transfer area A, the body profile thermal resistance R is calculated. ij4 Specifically, the thermal resistance R of the vehicle body profile is calculated by the following formula: ij4 :

[0060]

[0061] Specifically, according to the embodiment provided in the present application, the first thermal resistance of the thermal insulation material in the heat transfer direction is calculated by the following steps:

[0062] The second thermal resistance per unit area of ​​a single layer of thermal insulation material is calculated based on the thermal conductivity corresponding to the thermal insulation material of the rail vehicle and the actual thickness of the thermal insulation material, and the sum of all second thermal resistances is used as the first thermal resistance of the thermal insulation material in the heat transfer direction.

[0063] For the above steps, in the specific implementation, firstly, the second thermal resistance per unit area of ​​the single-layer thermal insulation material is calculated based on the thermal conductivity λ corresponding to the thermal insulation material of the rail vehicle and the actual thickness δ of the thermal insulation material. The second thermal resistance is the ratio between the actual thickness δ and the thermal conductivity λ. Then, the sum of all the second thermal resistances is taken as the first thermal resistance R of the thermal insulation material in the heat transfer direction. ij3 .

[0064] Specifically, in the heat transfer direction, in addition to the thermal resistance discussed above, there are many other components such as cavities in the enclosure structure, which are coupled to form a complex heat transfer path, which is defined as the simplified thermal resistance R ij2Specifically, according to the embodiment provided in the present application, the simplified thermal resistance in the heat transfer direction is calculated by the following steps:

[0065] A: Obtain heat transfer coefficient test values ​​of a plurality of test vehicles, and calculate the thermal resistance test value of each test vehicle based on the heat transfer coefficient test value of each test vehicle.

[0066] Here, before calculating the heat transfer coefficient of the rail vehicle, a basic database will be established. The basic database contains a basic database of test results of K values ​​of different models; a basic database of thermal resistance of body profiles of different materials and a basic database of thermal resistance of different insulation materials. By referring to the values ​​of simplified thermal resistance per unit area of ​​past models according to the pedigree, a more accurate calculation value of the heat transfer coefficient can be obtained. For example, the model of the rail vehicle currently being calculated is of the same pedigree as Vehicle 1 and Vehicle 2 in the basic database, and the influencing factors such as body material, body structure, and cold protection layout plan are the same or similar. Here, Vehicle 1 and Vehicle 2 are used as test vehicles, and the calculation is performed based on the basic database of Vehicle 1 and Vehicle 2. This method has high accuracy and good stability.

[0067] For the above step A, in the specific implementation, it is firstly determined that multiple test vehicles are determined, and the heat transfer coefficient test values ​​of the multiple test vehicles are obtained. Here, as an example, the heat transfer coefficient test values ​​of test vehicles 1 to 6 are obtained as 2.30, 2.36, 2.37, 2.45, 2.16, and 2.36, respectively. And the thermal resistance test value of each test vehicle is calculated based on the heat transfer coefficient test value of each test vehicle. Specifically, the reciprocal of the heat transfer coefficient test value of the test vehicle is the thermal resistance test value of the test vehicle.

[0068] B: Determine a simplified thermal resistance preset value, and calculate a thermal resistance calculated value for each test vehicle based on the simplified thermal resistance preset value and a heat transfer coefficient test value of each test vehicle.

[0069] Here, the simplified thermal resistance preset value may be preset as a fixed value. For example, the simplified thermal resistance preset value may be a fixed value of 0.20, which is not specifically limited in this application.

[0070] For the above step B, in the specific implementation, the simplified thermal resistance preset value is first determined, and then the thermal resistance calculated value of each test vehicle is calculated based on the simplified thermal resistance preset value and the heat transfer coefficient test value of each test vehicle. Here, continuing the example in the above step A, based on the above 6 samples and the simplified thermal resistance preset value taking a fixed value of 0.20, the thermal resistance calculated values ​​of test vehicles 1 to 6 are 1.99, 2.09, 2.19, 2.27, 2.08, and 2.00, respectively.

[0071] C: An average deviation is determined based on the thermal resistance test value and the thermal resistance calculated value of each test vehicle, and a correction factor is calculated based on the average deviation.

[0072] D: Correcting the simplified thermal resistance preset value based on the correction coefficient to obtain the simplified thermal resistance.

[0073] For the above steps C to D, in the specific implementation, after the thermal resistance test value and the thermal resistance calculated value of each test vehicle are calculated, the average deviation is determined using the thermal resistance test value and the thermal resistance calculated value of each test vehicle, and then the correction coefficient is determined by the average deviation. Here, continuing the example in step B above, the average deviation between the calculated thermal resistance value and the thermal resistance test value is -10%, that is, the correction coefficient is 1 / (1-10%). Then, based on the correction coefficient, the simplified thermal resistance preset value is corrected to obtain the simplified thermal resistance. Continuing the above example, the corrected simplified thermal resistance is taken as 0.2 / (1-10%), and the corrected simplified thermal resistance is used for subsequent calculations.

[0074] In this way, according to the above steps A to D, when calculating the simplified thermal resistance, past vehicle models are taken as the research object, a fixed value is taken for the simplified thermal resistance to obtain an estimated value of K value, and then the deviation of this calculation method is determined based on the results of the K value test, and the average correction coefficient is determined based on all samples and the result is corrected.

[0075] S103: For each regional model, a regional thermal resistance value of the regional model is calculated based on the structural thermal resistance values ​​of a plurality of structural models corresponding to the regional model.

[0076] With respect to the above step S103, in a specific implementation, for each regional model, the regional thermal resistance value of the regional model is calculated based on the structural thermal resistance values ​​of multiple structural models corresponding to the regional model. Here, as an example, it is assumed that there are j structural models in the regional model. Since the thermal resistance of each structural model is in parallel, the regional thermal resistance value R of the regional model is calculated by the following formula: i :

[0077]

[0078] S104, calculating a total thermal resistance value of the rail vehicle based on the regional thermal resistance value of each regional model, and calculating a heat transfer coefficient of the rail vehicle based on the total thermal resistance value.

[0079] For the above step S104, in the specific implementation, after the regional thermal resistance value of each regional model is calculated, the total thermal resistance value of the rail vehicle is calculated according to the regional thermal resistance value of each regional model. Here, since the thermal resistances of each regional model are also in parallel, the calculation method of the total thermal resistance value is the same as the calculation method of the regional thermal resistance value in the above step S103, which will not be repeated here. Then the heat transfer coefficient of the rail vehicle is calculated based on the total thermal resistance value. Specifically, the inverse of the total thermal resistance value of the rail vehicle is the heat transfer coefficient K value of the rail vehicle. In this way, the thermal resistance of each typical structure in the thermal resistance model and the K value of the whole vehicle can be obtained. According to the calculation results, the cold protection layout plan can be locally optimized, and several optimization calculation results can be obtained for comparison, so as to determine the final design plan.

[0080] The method for calculating the heat transfer coefficient of a rail vehicle provided in an embodiment of the present application comprises: first, establishing a thermal resistance model of the rail vehicle; wherein the thermal resistance model includes multiple regional models of the enclosure structure of the rail vehicle, each regional model includes multiple structural models, and each structural model includes multiple heat transfer layer models; then, for each structural model, calculating multiple heat transfer layer thermal resistance values ​​corresponding to the structural model, and calculating the structural thermal resistance value of the structural model based on the multiple heat transfer layer thermal resistance values; wherein each heat transfer layer model in the structural model corresponds to a different thermal layer thermal resistance value; for each regional model, calculating the regional thermal resistance value of the regional model based on the structural thermal resistance values ​​of the multiple structural models corresponding to the regional model; finally, calculating the total thermal resistance value of the rail vehicle based on the regional thermal resistance value of each regional model, and calculating the heat transfer coefficient of the rail vehicle based on the total thermal resistance value.

[0081] By constructing a thermal resistance model of a rail vehicle, this application can conveniently and intuitively perform modeling and output results, which greatly reduces the time consumption compared to conventional simulation analysis of the K value, improves the efficiency and accuracy of calculating the heat transfer coefficient of the rail vehicle, and has obvious practical value in the design or rapid verification of the layout of thermal insulation materials for rail vehicles, which is conducive to saving project development costs and shortening the R&D cycle.

[0082] See also Figure 3 , Figure 3 A schematic diagram of a device for calculating the heat transfer coefficient of a rail vehicle provided in an embodiment of the present application. Figure 3 As shown in , the computing device 300 includes:

[0083] The thermal resistance model establishment module 301 is used to establish a thermal resistance model of a rail vehicle; wherein the thermal resistance model includes a plurality of regional models of the enclosure structure of the rail vehicle, each regional model includes a plurality of structural models, and each structural model includes a plurality of heat transfer layer models;

[0084] The structural thermal resistance value calculation module 302 is used to calculate, for each structural model, a plurality of thermal resistance values ​​of heat transfer layers corresponding to the structural model, and calculate the structural thermal resistance value of the structural model based on the plurality of thermal resistance values ​​of the heat transfer layers; wherein each heat transfer layer model in the structural model corresponds to a different thermal resistance value of the heat layer;

[0085] A regional thermal resistance value calculation module 303 is used to calculate the regional thermal resistance value of each regional model based on the structural thermal resistance values ​​of multiple structural models corresponding to the regional model;

[0086] The heat transfer coefficient calculation module 304 is used to calculate the total thermal resistance value of the rail vehicle based on the regional thermal resistance value of each regional model, and calculate the heat transfer coefficient of the rail vehicle based on the total thermal resistance value.

[0087] Furthermore, the thermal resistance values ​​of the multiple heat transfer layers include a first convective heat transfer resistance between the air inside the vehicle and the inner wall of the vehicle, a second convective heat transfer resistance between the air outside the vehicle and the outer wall of the vehicle, the thermal resistance of the body profile, the first thermal resistance of the insulation material in the heat transfer direction, and the simplified thermal resistance in the heat transfer direction.

[0088] Furthermore, the structural thermal resistance calculation module 302 is further used to calculate the first convective heat transfer resistance and the second convective heat transfer resistance through the following steps:

[0089] Determining a natural convection surface heat transfer coefficient between the interior air of the rail vehicle and an inner wall of the vehicle, and calculating the first convection heat transfer thermal resistance based on the natural convection surface heat transfer coefficient and a heat transfer area;

[0090] A forced convection surface heat transfer coefficient between the air outside the rail vehicle and an outer wall of the vehicle is determined, and the second convection heat transfer thermal resistance is calculated based on the forced convection surface heat transfer coefficient and the heat transfer area.

[0091] Furthermore, the structural thermal resistance value calculation module 302 is also used to calculate the thermal resistance of the vehicle body profile through the following steps:

[0092] Determining the thermal conductivity corresponding to the body profile material of the rail vehicle;

[0093] The body profile thermal resistance is calculated based on the thermal conductivity, the actual thickness of the body profile material of the rail vehicle, and the heat transfer area.

[0094] Furthermore, the structural thermal resistance value calculation module 302 is also used to calculate the first thermal resistance of the thermal insulation material in the heat transfer direction through the following steps:

[0095] The second thermal resistance per unit area of ​​a single layer of thermal insulation material is calculated based on the thermal conductivity corresponding to the thermal insulation material of the rail vehicle and the actual thickness of the thermal insulation material, and the sum of all second thermal resistances is used as the first thermal resistance of the thermal insulation material in the heat transfer direction.

[0096] Furthermore, the structural thermal resistance value calculation module 302 is also used to calculate the simplified thermal resistance in the heat transfer direction through the following steps:

[0097] Acquiring heat transfer coefficient test values ​​of a plurality of test vehicles, and calculating a thermal resistance test value of each test vehicle based on the heat transfer coefficient test value of each test vehicle;

[0098] Determining a simplified thermal resistance preset value, and calculating a thermal resistance calculated value of each test vehicle based on the simplified thermal resistance preset value and a heat transfer coefficient test value of each test vehicle;

[0099] determining an average deviation based on the thermal resistance test value and the thermal resistance calculated value of each test vehicle, and calculating a correction factor based on the average deviation;

[0100] The simplified thermal resistance preset value is corrected based on the correction coefficient to obtain the simplified thermal resistance.

[0101] See also Figure 4 , Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. Figure 4 As shown in , the electronic device 400 includes a processor 410 , a memory 420 and a bus 430 .

[0102] The memory 420 stores machine-readable instructions executable by the processor 410. When the electronic device 400 is running, the processor 410 communicates with the memory 420 via the bus 430. When the machine-readable instructions are executed by the processor 410, the above-mentioned Figure 1 The steps of the method for calculating the heat transfer coefficient of a rail vehicle in the method embodiment shown and the specific implementation thereof can be referred to the method embodiment, which will not be described in detail here.

[0103] The present application also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the computer program can execute the above-mentioned Figure 1 The steps of the method for calculating the heat transfer coefficient of a rail vehicle in the method embodiment shown, and the specific implementation method thereof can be referred to the method embodiment, which will not be described in detail here.

[0104] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0105] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0106] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0107] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0108] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present application can essentially be embodied in the form of a software product, or in other words, the part that contributes to the prior art or the part of the technical solution. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0109] It should be noted that similar numbers and letters represent similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description and are not to be understood as indicating or implying relative importance.

[0110] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The protection scope of the present application is not limited thereto. Although the present application is described in detail with reference to the above-mentioned embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-mentioned embodiments within the technical scope disclosed in the present application, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for calculating the heat transfer coefficient of a rail vehicle, characterized in that: The calculation method includes: Establishing a thermal resistance model of a rail vehicle; wherein the thermal resistance model includes a plurality of regional models of the enclosure structure of the rail vehicle, each regional model includes a plurality of structural models, and each structural model includes a plurality of heat transfer layer models; For each structural model, multiple heat transfer layer thermal resistance values ​​corresponding to the structural model are calculated, and the structural thermal resistance value of the structural model is calculated based on the multiple heat transfer layer thermal resistance values; wherein each heat transfer layer model in the structural model corresponds to a different thermal layer thermal resistance value; For each regional model, a regional thermal resistance value of the regional model is calculated based on the structural thermal resistance values ​​of multiple structural models corresponding to the regional model; A total thermal resistance value of the rail vehicle is calculated based on the regional thermal resistance value of each regional model, and a heat transfer coefficient of the rail vehicle is calculated based on the total thermal resistance value.

2. The calculation method according to claim 1, characterized in that: The multiple thermal resistance values ​​of the heat transfer layers include a first convective heat transfer resistance between the air inside the vehicle and the inner wall of the vehicle, a second convective heat transfer resistance between the air outside the vehicle and the outer wall of the vehicle, a thermal resistance of the body profile, a first thermal resistance of the insulation material in the heat transfer direction, and a simplified thermal resistance in the heat transfer direction.

3. The calculation method according to claim 2, characterized in that: The first convective heat transfer resistance and the second convective heat transfer resistance are calculated by the following steps: Determining a natural convection surface heat transfer coefficient between the interior air of the rail vehicle and an inner wall of the vehicle, and calculating the first convection heat transfer thermal resistance based on the natural convection surface heat transfer coefficient and a heat transfer area; A forced convection surface heat transfer coefficient between the air outside the rail vehicle and an outer wall of the vehicle is determined, and the second convection heat transfer thermal resistance is calculated based on the forced convection surface heat transfer coefficient and the heat transfer area.

4. The calculation method according to claim 2, characterized in that: The thermal resistance of the body profile is calculated by the following steps: Determining the thermal conductivity corresponding to the body profile material of the rail vehicle; The body profile thermal resistance is calculated based on the thermal conductivity, the actual thickness of the body profile material of the rail vehicle, and the heat transfer area.

5. The calculation method according to claim 2, characterized in that: Calculate the first thermal resistance of the insulation material in the heat transfer direction by the following steps: The second thermal resistance per unit area of ​​a single layer of thermal insulation material is calculated based on the thermal conductivity corresponding to the thermal insulation material of the rail vehicle and the actual thickness of the thermal insulation material, and the sum of all second thermal resistances is used as the first thermal resistance of the thermal insulation material in the heat transfer direction.

6. The calculation method according to claim 2, characterized in that: The simplified thermal resistance in the heat transfer direction is calculated by the following steps: Acquiring heat transfer coefficient test values ​​of a plurality of test vehicles, and calculating a thermal resistance test value of each test vehicle based on the heat transfer coefficient test value of each test vehicle; Determining a simplified thermal resistance preset value, and calculating a thermal resistance calculated value of each test vehicle based on the simplified thermal resistance preset value and a heat transfer coefficient test value of each test vehicle; determining an average deviation based on the thermal resistance test value and the thermal resistance calculated value of each test vehicle, and calculating a correction factor based on the average deviation; The simplified thermal resistance preset value is corrected based on the correction coefficient to obtain the simplified thermal resistance.

7. A device for calculating the heat transfer coefficient of a rail vehicle, characterized in that: The computing device comprises: A thermal resistance model building module is used to build a thermal resistance model of a rail vehicle; wherein the thermal resistance model includes a plurality of regional models of the enclosure structure of the rail vehicle, each regional model includes a plurality of structural models, and each structural model includes a plurality of heat transfer layer models; A structural thermal resistance value calculation module is used to calculate, for each structural model, a plurality of thermal resistance values ​​of heat transfer layers corresponding to the structural model, and calculate the structural thermal resistance value of the structural model based on the plurality of thermal resistance values ​​of the heat transfer layers; wherein each heat transfer layer model in the structural model corresponds to a different thermal resistance value of the heat layer; A regional thermal resistance value calculation module, used for calculating the regional thermal resistance value of each regional model based on the structural thermal resistance values ​​of multiple structural models corresponding to the regional model; The heat transfer coefficient calculation module is used to calculate the total thermal resistance value of the rail vehicle based on the regional thermal resistance value of each regional model, and calculate the heat transfer coefficient of the rail vehicle based on the total thermal resistance value.

8. The computing device according to claim 7, characterized in that: The multiple thermal resistance values ​​of the heat transfer layers include a first convective heat transfer resistance between the air inside the vehicle and the inner wall of the vehicle, a second convective heat transfer resistance between the air outside the vehicle and the outer wall of the vehicle, a thermal resistance of the body profile, a first thermal resistance of the insulation material in the heat transfer direction, and a simplified thermal resistance in the heat transfer direction.

9. An electronic device, characterized in that: include: A processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the electronic device is running, the processor and the memory communicate through the bus, and the machine-readable instructions are executed by the processor to execute the steps of the method for calculating the heat transfer coefficient of a rail vehicle as described in any one of claims 1 to 6.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for calculating the heat transfer coefficient of a rail vehicle as claimed in any one of claims 1 to 6 are executed.

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