Compartment steady-state temperature field simulation method and device, storage medium and product

Abstract

The invention discloses a compartment steady-state temperature field simulation method and device, a storage medium and a product. The method comprises the steps that a compartment three-dimensional model containing a complete passenger area and an air duct structure is constructed; performing gridding processing on the carriage three-dimensional model to obtain a carriage grid model; carrying out solving parameter setting on the compartment grid model; performing simulation calculation on the carriage network model after setting the solving parameters to obtain a carriage pressure field, a carriage speed field and a carriage temperature field; judging whether the compartment grid model is valid or not according to the distribution conditions of a compartment pressure field, a compartment speed field and a compartment temperature field; and whether the compartment refrigeration effect meets the requirement or not is judged according to the compartment temperature field. The evaluation efficiency of the compartment refrigeration scheme is greatly improved, the evaluation cost of the compartment refrigeration scheme is remarkably reduced, and the problems of long time and high cost caused by a trial-production mode are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicle body structure design, and in particular relates to a vehicle compartment steady-state temperature field simulation method, equipment, storage medium and product. Background Art

[0002] At present, the cabin temperature field under air-conditioning refrigeration conditions is mainly obtained through experiments. Both constant temperature cabin experiments (seasons with low ambient temperature, such as spring or winter) and open-air experiments (such as summer) require a trial production cycle. The trial production cycle includes prototype vehicle trial production, prototype vehicle testing, prototype vehicle rectification and prototype vehicle acceptance. The entire trial production cycle is not only long, but also consumes considerable funds. Summary of the invention

[0003] The purpose of the present invention is to provide a method, device, storage medium and product for simulating the steady-state temperature field of a vehicle cabin, so as to solve the problem that in traditional technology, the temperature field of the vehicle cabin under air-conditioning refrigeration conditions is mainly obtained through experiments, which requires a trial production cycle, resulting in a long time and high cost.

[0004] The present invention solves the above technical problems through the following technical solutions: a method for simulating a steady-state temperature field in a carriage, comprising:

[0005] Step 1: Based on the cabin structure, build a three-dimensional model of the cabin including the complete passenger area and air duct structure;

[0006] Step 2: Meshing the three-dimensional model of the carriage to obtain a carriage mesh model;

[0007] Step 3: Setting solution parameters for the cabin grid model; wherein the solution parameters include cabin operating conditions, turbulence model and fluid medium; the cabin operating conditions include cabin state and boundary conditions; the cabin state includes passenger door state and air duct structure state; the boundary conditions include air conditioning outlet boundary and air volume, air conditioning outlet temperature, air conditioning return air outlet boundary, multi-layer wall thermal boundary and single-layer wall thermal boundary;

[0008] Step 4: Simulate the carriage network model after setting the solution parameters to obtain the carriage pressure field, carriage velocity field and carriage temperature field;

[0009] Step 5: judging whether the compartment grid model is valid according to the distribution of the compartment pressure field, the compartment velocity field and the compartment temperature field; if so, proceed to step 6; otherwise, proceed to step 3;

[0010] Step 6: Determine whether the cabin cooling effect meets the requirements based on the cabin temperature field. If not, change the cabin structure and go to step 1; if yes, output a cabin that meets the refrigeration technical requirements.

[0011] Furthermore, in the three-dimensional model of the vehicle compartment, a gap is used to equalize the sealing effect of the hinged joint of the air duct cover and the sealing effect of the vehicle door.

[0012] Furthermore, in the step 2, the three-dimensional model of the carriage is meshed using a polyhedral mesh, which specifically includes:

[0013] Firstly, a two-dimensional surface in the three-dimensional model of the carriage is meshed;

[0014] Then, the three-dimensional surface in the three-dimensional model of the carriage is meshed and the surface boundary type is defined.

[0015] Furthermore, the air-conditioning outlet boundary is set as a velocity boundary, and the air volume is set as r% of the air-conditioning theoretical evaporation air volume; the air-conditioning outlet temperature is set using a temperature-time function relationship fitted by experimental data; and the air-conditioning return air outlet boundary is set as a pressure outlet.

[0016] Furthermore, the equivalent convection heat transfer coefficient and the comprehensive temperature of the solar surface are used to set the multi-layer wall thermal boundary;

[0017] The multi-layer wall surface includes a top cover, a side wall, a floor, a front wall and a rear wall; the calculation formula of the equivalent convection heat transfer coefficient of the multi-layer wall surface is:

[0018]

[0019] Among them, C i represents the equivalent convection heat transfer coefficient of the i-th wall, α H represents the heat release coefficient of the outer surface of the car, α B Indicates the heat release coefficient of the inner surface of the car, δ ij represents the thickness of the jth layer of thermal insulation material on the i-th wall, λ ij represents the thermal conductivity of the jth layer of insulation material on the ith wall, and n represents the number of layers on the ith wall;

[0020] The calculation formula of the solar radiation surface comprehensive temperature of the multi-layer wall is:

[0021]

[0022] Among them, T zi represents the solar surface integrated temperature of the ith wall, T H represents the air temperature outside the cabin, ρ i represents the absorption ratio of the outer surface of the i-th wall to solar radiation, I i Represents the total solar radiation intensity received by the outer surface of the i-th wall.

[0023] Preferably, a ray tracing method is used to calculate the total solar radiation intensity received by the outer surface of the multi-layer wall.

[0024] Furthermore, in step 5, when the following conditions are met at the same time, the compartment grid model is valid:

[0025] The location where the wall boundary layer flow separation occurs is correct;

[0026] The gradient of velocity field and pressure field at small-size structures is reasonable;

[0027] The change gradient of the temperature field in the carriage and the local pressure field are reasonable.

[0028] Furthermore, in step 6, judging whether the cabin cooling effect meets the requirements according to the cabin temperature field includes:

[0029] Extracting the temperature of corresponding points from the compartment temperature field according to the monitoring points in the test specification;

[0030] Determine whether the cabin cooling effect meets the requirements based on the extracted temperatures at each point.

[0031] Based on the same concept, the present invention provides an electronic device, including a memory, a processor, and a computer program / instruction stored in the memory, wherein the processor executes the computer program / instruction to implement the above-mentioned vehicle cabin steady-state temperature field simulation method.

[0032] Based on the same concept, the present invention provides a computer-readable storage medium having a computer program / instruction stored thereon, which, when executed by a processor, implements the above-mentioned vehicle compartment steady-state temperature field simulation method.

[0033] Based on the same concept, the present invention provides a computer program product, including a computer program / instruction, which implements the above-mentioned vehicle cabin steady-state temperature field simulation method when executed by a processor.

[0034] Beneficial Effects

[0035] Compared with the prior art, the advantages of the present invention are:

[0036] The present invention adopts simulation technology to evaluate whether the cabin temperature field under air-conditioning refrigeration conditions meets the requirements. No trial production cycle is required, which greatly improves the evaluation efficiency of the cabin refrigeration solution, significantly reduces the evaluation cost of the cabin refrigeration solution, and solves the problems of long time and high cost caused by the trial production method.

[0037] The present invention uses the equivalent convection heat transfer coefficient and the comprehensive temperature of the sunlight surface to set the thermal boundary of the multi-layer wall. The multi-layer wall does not need to be layered when modeling, which simplifies the modeling process. The equivalent convection heat transfer coefficient and the comprehensive temperature of the sunlight surface are used to simulate the heat transfer effect of the multi-layer wall, thereby improving the simulation accuracy of the temperature field. The present invention uses a ray tracing algorithm to simulate the influence of solar radiation on the temperature field of the car, which can more accurately simulate the influence of solar radiation on the sides and front of the driver's cab, thereby improving the simulation accuracy of the temperature field of the driver's cab. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only one embodiment of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 is a flow chart of a method for simulating a steady-state temperature field in a vehicle compartment according to an embodiment of the present invention;

[0040] Figure 2 is a three-dimensional model of a bus compartment in an embodiment of the present invention;

[0041] Figure 3 is a schematic diagram of equivalent processing of the sealing effect of the front passenger door in an embodiment of the present invention;

[0042] Figure 4 Schematic diagram of equivalent processing of the sealing effect at the hinged joint of the air duct cover in the embodiment of the present invention;

[0043] Figure 5 is a schematic diagram of a two-dimensional surface mesh in an embodiment of the present invention;

[0044] Figure 6 is a schematic diagram of a three-dimensional polyhedron mesh in an embodiment of the present invention;

[0045] Figure 7 is a schematic diagram of one side of a three-dimensional model of a carriage in an embodiment of the present invention;

[0046] Figure 8 It is a schematic diagram of the other side of the three-dimensional model of the carriage in an embodiment of the present invention.

[0047] Explanation of the reference numerals: 1-top cover, 11-air conditioning return vent, 12-air conditioning outlet, 13-air duct, 2-front panel, 21-windshield, 3-side panel, 31-side window glass, 32-passenger door glass, 4-rear panel, 5-floor. DETAILED DESCRIPTION

[0048] The following is a clear and complete description of the technical solutions in the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] The technical solution of the present application is described in detail with specific embodiments below. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0050] like Figure 1 As shown, a method for simulating a steady-state temperature field in a vehicle compartment provided by an embodiment of the present invention comprises the following steps:

[0051] Step 1: Based on the car structure, build a three-dimensional model of the car that includes the complete passenger area and air duct structure.

[0052] This embodiment takes a bus compartment as an example, and the constructed three-dimensional model of the compartment is as follows: Figure 2 As shown. In the three-dimensional model of the car, structures that have little impact on the process, such as air ducts and passenger handrails, are simplified, which simplifies the construction process of the three-dimensional model. In view of the poor sealing of the bus air duct, gaps are used to equalize the sealing effect of the hinges of the passenger door and air duct cover. In the actual car structure, a sealing strip is provided at the hinge of the front passenger door. Aging causes the sealing strip to warp, affecting the sealing effect. In order to more accurately simulate the temperature field of the car, a gap is used to equalize the sealing effect of the sealing strip of the front passenger door, as shown in Figure 3 In this embodiment, the sealing effect of the sealing strip of the front passenger door is equivalent to a gap of 10 mm. The middle passenger door usually adopts a plug door, which is generally sealed with a brush, and the sealing performance is worse than that of the sealing strip. Therefore, the brush sealing effect of the middle passenger door is equivalent to a gap of 15 mm. Similarly, the sealing effect of the rubber strip at the hinge of the air duct cover is equivalent to a gap of 10 mm, as shown in FIG. Figure 4 shown.

[0053] Step 2: Mesh the three-dimensional model of the carriage to obtain a carriage mesh model.

[0054] In a specific embodiment of the present invention, the three-dimensional model of the carriage is meshed using a polyhedral mesh, which specifically includes:

[0055] Step 2.1: First, mesh the two-dimensional surface of the three-dimensional model of the carriage, such as Figure 5 shown.

[0056] Among them, the mesh size of the air duct outlet and the equivalent gap is controlled at about 2mm, the mesh size of the sealing structure such as the passenger door is controlled at about 4mm, and the mesh size of other two-dimensional surfaces gradually changes to about 64mm. The mesh size must meet the needs of high-precision simulation analysis, and the surface mesh must be a completely closed structure without free edges and repeated units.

[0057] Step 2.2: Then mesh the 3D surface in the 3D model of the carriage and define the surface boundary type, such as Figure 6 shown.

[0058] The surface boundary types include inlet, outlet and wall. For the fluid region, three-layer boundary layer meshes are made. The boundary layer making method adopts smooth-transition. The volume mesh growth ratio is 1.2. Other settings adopt default settings.

[0059] The gridding processing step of the present invention reduces the number of grid units while ensuring simulation accuracy, thereby reducing the demand for computer hardware.

[0060] Step 3: Set the solution parameters for the car mesh model.

[0061] The solution parameters include the cabin condition, turbulence model and fluid medium; the cabin condition includes the cabin state and boundary conditions; the cabin state includes the passenger door state and the air duct structure state. Among them, the cabin state includes whether the cabin is in the parking state, the cabin is affected by solar radiation, the passenger door state, the number of passengers and the fresh air state. For example, the cabin is in the parking state, the cabin is exposed to the sun, the passenger door is closed, there are no passengers, no fresh air, the air duct outlet is fully open, and the air conditioner evaporator fan is turned on the maximum gear.

[0062] like Figure 7 and Figure 8 As shown, the boundary conditions include the boundary of the air-conditioning outlet 12 and its air volume, the temperature of the air-conditioning outlet 12, the boundary of the air-conditioning return air outlet 11, the multi-layer wall thermal boundary and the single-layer wall thermal boundary. In this embodiment, the boundary of the air-conditioning outlet 12 is set as the velocity boundary, and the air volume is set as r% of the theoretical evaporation air volume of the air-conditioning; the temperature of the air-conditioning outlet 12 is set by the temperature-time function relationship fitted by the test data; the boundary of the air-conditioning return air outlet 11 is set as the pressure outlet, and the surface pressure is set to 0Pa. For the aluminum alloy air duct 13, the value of r is 50.

[0063] The multi-layer wall is usually an opaque wall, and the multi-layer wall of the carriage includes a roof 1, a side wall 3, a floor 5, a front wall 2, and a rear wall 4. In this embodiment, the calculation formula of the equivalent convection heat transfer coefficient of the multi-layer wall is:

[0064]

[0065] Among them, Ci represents the equivalent convection heat transfer coefficient of the i-th wall; α H Indicates the heat release coefficient of the outer surface of the car; α B Indicates the heat release coefficient of the inner surface of the car; δ ij represents the thickness of the jth layer of thermal insulation material on the ith wall, in m; λ ij It represents the thermal conductivity of the jth layer of insulation material on the i-th wall, in units of W / (m·K); n represents the number of layers on the i-th wall. H Usually taken as 146W / (m 2 ·K); when the air conditioner is in cooling state, α B It can be taken as 60W / (m 2 ·K).

[0066] For example, for a certain model of bus cabin roof 1 and side panel 3, which include skin, foaming agent and interior panel, the thermal conductivity of the skin, foaming agent and interior panel are 54W / (m·K), 0.032W / (m·K) and 0.04W / (m·K), respectively. Therefore, the calculation formula of the equivalent convection heat transfer coefficient of the roof 1 or side panel 3 is:

[0067]

[0068] For example, for a certain model of bus, the front enclosure 2 and the rear enclosure 4 include fiberglass, an air layer and an instrument panel, and the thermal conductivity coefficients of the fiberglass, the air layer and the instrument panel are 0.4W / (m·K), 6.4W / (m·K) and 0.032W / (m·K), respectively. Therefore, the calculation formula for the equivalent convection heat transfer coefficient of the front enclosure 2 or the rear enclosure 4 is:

[0069]

[0070] For example, for a certain model of bus compartment floor 5, it includes PVC board, floor leather and heat insulation and shock absorption layer, the thermal conductivity of PVC board, floor leather and heat insulation and shock absorption layer are 0.17W / (m·K), 0.12W / (m·K) and 0.04W / (m·K) respectively. Therefore, the calculation formula of the equivalent convection heat transfer coefficient of the floor 5 is:

[0071]

[0072] For a single-layer wall surface of the vehicle compartment, such as the side window glass 31, the windshield glass 21 and the passenger door glass 32, the outer surface heat release coefficient α is directly set. H , glass material and glass thickness.

[0073] The roof (i.e., the top cover 1), the side wall 3, the front wall 2, and the rear wall 4 are exposed to sunlight, so it is necessary to calculate the comprehensive temperature of the sun-exposed surface of the roof (i.e., the top cover 1), the side wall 3, the front wall 2, and the rear wall 4. In a specific embodiment of the present invention, the calculation formula for the comprehensive temperature of the sun-exposed surface of the top cover 1, the side wall 3, the front wall 2, or the rear wall 4 is:

[0074]

[0075] Among them, T zi represents the comprehensive temperature of the solar radiation surface of the ith wall; T H represents the temperature outside the car; ρ i I represents the absorption ratio of the outer surface of the i-th wall to solar radiation; i It represents the total solar radiation intensity received by the outer surface of the i-th wall, which includes direct radiation intensity and scattered radiation intensity. The value of scattered radiation intensity is 35~47 (W / m 2 ).

[0076] For example, for a certain model of bus roof 1, its sunlit surface comprehensive temperature is specifically:

[0077]

[0078] The absorption ratio ρ of the outer surface of the vehicle body to solar radiation is related to the color, roughness and usage of the vehicle body, and its value range is usually between 0.5 and 0.9. In this embodiment, the absorption ratio of the outer surface of the top cover 1 to solar radiation is the average value of 0.5 and 0.9, that is, ρ i Take 0.7; the equivalent convection heat transfer coefficient of the top cover 1 is calculated in formula (2); the total solar radiation intensity received by the outer surface of the top cover 1 can be obtained by using a ray tracing algorithm, and the total solar radiation intensity received by the outer surface of the top cover 1 is the radiation intensity of the horizontal plane.

[0079] For example, for a side panel 3 of a bus of a certain model, the comprehensive temperature of the sunlit surface is:

[0080]

[0081] In this embodiment, the absorption ratio of the outer surface of the side panel 3 to solar radiation is i The average of 0.5 and 0.9 is taken, that is, 0.7; the equivalent convection heat transfer coefficient of the side enclosure 3 is calculated in formula (2); the total solar radiation intensity received by the outer surface of the side enclosure 3 can be obtained by using a ray tracing algorithm. In this embodiment, the total solar radiation intensity received by the outer surface of the side enclosure 3 is 100. Similarly, the comprehensive temperature of the sunlit surface of the front enclosure 2 and the rear enclosure 4 is calculated using formula (5).

[0082] In a specific embodiment of the present invention, a ray tracing method is used to calculate the total solar radiation intensity received by the outer surface of the multi-layer wall, that is, to simulate solar radiation heat transfer. The ray tracing method is in a solar calculator, which calculates the solar radiation intensity and the angle of incidence through the longitude and latitude, date and weather conditions of the area where the vehicle is located, and accurately simulates the influence of solar radiation on the vehicle compartment. The glass wall is a single-layer wall, and the transmittance and absorptivity are set according to the type of glass. If there are interior decorations, the absorptivity of the interior decorations can be uniformly set to 0.7.

[0083] The floor 5 is not exposed to sunlight. In this embodiment, the temperature of the floor 5 is increased by 2-3°C based on the ambient temperature, that is, 35°C+(2-3)=37-38°C.

[0084] In this embodiment, the k-ωSST model is selected as the turbulence model, and the fluid medium is set to incompressible ideal air.

[0085] Step 4: Perform simulation calculation on the carriage network model after setting the solution parameters to obtain the carriage pressure field, carriage velocity field and carriage temperature field.

[0086] Step 5: Determine whether the compartment grid model is valid based on the distribution of the compartment pressure field, compartment velocity field and compartment temperature field. If so, proceed to step 6; otherwise, proceed to step 3.

[0087] Check the carriage pressure field, carriage velocity field and carriage temperature field to evaluate whether the carriage mesh model is valid. When the following conditions are met at the same time, it indicates that the carriage mesh model is valid:

[0088] Condition 1: The location where the wall boundary layer flow separation occurs is correct;

[0089] Condition 2: The change gradient of velocity field and pressure field at small-sized structures such as air duct outlet is reasonable;

[0090] Condition three: The changing gradient of the temperature field in the carriage and the local pressure field (such as locations where flow separation is severe or there are eddies) are reasonable.

[0091] When the compartment grid model is determined to be invalid, the main adjustment measures are: re-making the compartment grid model, reducing the grid size of the local area, and improving the simulation resolution; adjusting the local boundary layer thickness to obtain a reasonable boundary layer Yplus value until the compartment grid model is valid. In this embodiment, the boundary layer Yplus value is about 1.

[0092] Step 6: Determine whether the cabin cooling effect meets the requirements based on the cabin temperature field. If not, change the cabin structure and go to step 1; if yes, output a cabin that meets the refrigeration technical requirements.

[0093] In a specific embodiment of the present invention, judging whether the cabin cooling effect meets the requirements according to the cabin temperature field includes:

[0094] Extract the temperature of the corresponding point from the compartment temperature field according to the monitoring point in the test specification;

[0095] Determine whether the cabin cooling effect meets the requirements based on the extracted temperatures at each point.

[0096] Taking buses as an example, the Technical Requirements for Passenger Bus Air Conditioning Systems shows the test specifications and specifies the locations of monitoring points. For example, when the outside temperature is above 30°C and the inside temperature is above 45°C, the air conditioner is turned on at full power for cooling, and the average temperature inside the car drops to 26°C within 30 minutes; the temperature difference between the front, middle and rear of the car is ≤3°C; the temperature difference between the driver's head and feet is ≤3°C, which meets the requirements for the cooling effect of the car.

[0097] When the cabin cooling effect requirements are not met, change the cabin structure. For example, when the overall cabin temperature drops slowly (for example, it cannot drop to 26°C within 30 minutes), it may be that the cabin insulation effect is poor, the air conditioning cooling power is too small, the glass transmittance is too high, etc., and improvements should be made in these directions; when the temperature distribution in the front and back of the cabin is uneven, evaluate the wind speed and volume distribution of the air duct outlet, add an air guide cover structure or adjust the air duct outlet distribution plan.

[0098] The method of the present invention has been applied to a batch of real vehicles. Except for the temperature field in the driver's area, the simulation error of the temperature field in other areas can be controlled within 5%. The temperature field in the driver's area is significantly affected by solar radiation and cannot be completely restored to the test site, so the simulation error is a little larger.

[0099] Example 2

[0100] An embodiment of the present invention further provides an electronic device, which includes: a memory, a processor, and a computer program / instructions stored in the memory, and the processor executes the computer program / instructions to implement the vehicle compartment steady-state temperature field simulation method in the embodiment of the present application.

[0101] Although not shown, the electronic device includes a processor, which can perform various appropriate operations and processes according to the program and / or data stored in the read-only memory (ROM) or the program and / or data loaded from the storage portion into the random access memory (RAM). The processor can be a multi-core processor, or it can include multiple processors. In some embodiments, the processor can include a general main processor and one or more special coprocessors, such as a central processing unit, a graphics processing unit (GPU), a neural network processor (NPU), a digital signal processor (DSP), etc. In RAM, various programs and data required for device operation are also stored. The processor, ROM and RAM are connected to each other via a bus. The input / output (I / O) interface is also connected to the bus.

[0102] The processor and the memory are used together to execute the program / instructions stored in the memory. When the program / instructions are executed by the computer, the methods, steps or functions described in the above embodiments can be implemented.

[0103] Although not shown, an embodiment of the present invention further provides a computer-readable storage medium having a computer program / instruction stored thereon, which, when executed by a processor, implements the vehicle compartment steady-state temperature field simulation method in the embodiment of the present application.

[0104] Storage media in embodiments of the present invention include permanent and non-permanent, removable and non-removable items that can be implemented by any method or technology to store information. Examples of storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic disk storage or other magnetic storage devices or any other non-transmission medium that can be used to store information that can be accessed by a computing device.

[0105] Readable storage media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include temporary computer-readable media (transitory media), such as modulated data signals and carrier waves.

[0106] Although not shown, an embodiment of the present invention further provides a computer program product, including: a computer program / instruction, which, when executed by a processor, implements the vehicle compartment steady-state temperature field simulation method in the embodiment of the present application.

[0107] What is disclosed above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or modifications within the technical scope disclosed in the present invention, which should be covered within the protection scope of the present invention.

Claims

1. A method for simulating a steady-state temperature field in a carriage, characterized in that: The simulation method comprises: Step 1: Based on the cabin structure, build a three-dimensional model of the cabin including the complete passenger area and air duct structure; Step 2: Meshing the three-dimensional model of the carriage to obtain a carriage mesh model; Step 3: Setting solution parameters for the cabin grid model; wherein the solution parameters include cabin operating conditions, turbulence model and fluid medium; the cabin operating conditions include cabin state and boundary conditions; the cabin state includes passenger door state and air duct structure state; the boundary conditions include air conditioning outlet boundary and air volume, air conditioning outlet temperature, air conditioning return air outlet boundary, multi-layer wall thermal boundary and single-layer wall thermal boundary; Step 4: Simulate the carriage network model after setting the solution parameters to obtain the carriage pressure field, carriage velocity field and carriage temperature field; Step 5: judging whether the compartment grid model is valid according to the distribution of the compartment pressure field, the compartment velocity field and the compartment temperature field; if so, proceed to step 6; otherwise, proceed to step 3; Step 6: Determine whether the cabin cooling effect meets the requirements based on the cabin temperature field. If not, change the cabin structure and go to step 1. If yes, output a cabin that meets the refrigeration technical requirements.

2. The method for simulating a steady-state temperature field in a vehicle compartment according to claim 1, characterized in that: In the three-dimensional model of the vehicle compartment, a gap is used to equalize the sealing effect of the hinged joint of the air duct cover and the sealing effect of the vehicle door.

3. The method for simulating a steady-state temperature field in a vehicle compartment according to claim 1, characterized in that: In the step 2, meshing the three-dimensional model of the carriage is performed using a polyhedral mesh, which specifically includes: Firstly, a two-dimensional surface in the three-dimensional model of the carriage is meshed; Then, the three-dimensional surface in the three-dimensional model of the carriage is meshed and the surface boundary type is defined.

4. The method for simulating a steady-state temperature field in a vehicle compartment according to claim 1, characterized in that: The air outlet boundary of the air conditioner is set as the velocity boundary, and the air volume is set as r% of the theoretical evaporation air volume of the air conditioner; the air outlet temperature of the air conditioner is set using the temperature-time function relationship fitted by the test data; and the return air outlet boundary of the air conditioner is set as the pressure outlet.

5. The method for simulating a steady-state temperature field in a vehicle compartment according to claim 1, characterized in that: The equivalent convection heat transfer coefficient and the comprehensive temperature of the solar surface are used to set the multi-layer wall thermal boundary; The multi-layer wall surface includes a top cover, a side wall, a floor, a front wall and a rear wall; the calculation formula of the equivalent convection heat transfer coefficient of the multi-layer wall surface is: Among them, C i represents the equivalent convection heat transfer coefficient of the i-th wall, α H represents the heat release coefficient of the outer surface of the car, α B Indicates the heat release coefficient of the inner surface of the car, δ ij represents the thickness of the jth layer of thermal insulation material on the i-th wall, λ ij represents the thermal conductivity of the jth layer of insulation material on the ith wall, and n represents the number of layers on the ith wall; The calculation formula of the solar radiation surface comprehensive temperature of the multi-layer wall is: Among them, T zi represents the solar surface integrated temperature of the ith wall, T H represents the air temperature outside the cabin, ρ i represents the absorption ratio of the outer surface of the i-th wall to solar radiation, I i represents the total solar radiation intensity received by the outer surface of the i-th wall; Preferably, a ray tracing method is used to calculate the total solar radiation intensity received by the outer surface of the multi-layer wall.

6. The method for simulating a steady-state temperature field in a vehicle compartment according to claim 1, characterized in that: In step 5, when the following conditions are met at the same time, the compartment grid model is valid: The location where the wall boundary layer flow separation occurs is correct; The gradient of velocity field and pressure field at small-size structures is reasonable; The change gradient of the temperature field in the carriage and the local pressure field are reasonable.

7. The method for simulating a steady-state temperature field in a vehicle compartment according to any one of claims 1 to 6, characterized in that: In step 6, judging whether the cabin cooling effect meets the requirements according to the cabin temperature field includes: Extracting the temperature of corresponding points from the compartment temperature field according to the monitoring points in the test specification; Determine whether the cabin cooling effect meets the requirements based on the extracted temperatures at each point.

8. An electronic device comprising a memory, a processor, and a computer program / instruction stored in the memory, characterized in that: The processor executes the computer program / instructions to implement the vehicle cabin steady-state temperature field simulation method according to any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program / instruction stored thereon, characterized in that: When the computer program / instruction is executed by a processor, the method for simulating a steady-state temperature field in a vehicle compartment as claimed in any one of claims 1 to 7 is implemented.

10. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instruction is executed by a processor, the method for simulating a steady-state temperature field in a vehicle compartment as claimed in any one of claims 1 to 7 is implemented.

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