Method and device for evaluating hot air backflow of engine compartment and computer equipment

Abstract

The application relates to an engine compartment hot air backflow evaluation method and device, computer equipment, a storage medium and a computer program product. The method comprises the following steps: acquiring simulation data and test data of a vehicle engine compartment under a target working condition; the simulation data comprises a front projection area of a intercooler, a front projection area of a radiator, an air inlet amount of the intercooler and an actual temperature at the front end of the radiator, and the test data comprises a heat dissipation amount of the intercooler; determining a temperature rise of the intercooler according to the heat dissipation amount and the air inlet amount of the intercooler; determining an equivalent temperature rise corresponding to the temperature rise of the intercooler according to the front projection area of the intercooler, the front projection area of the radiator and the temperature rise of the intercooler; determining a theoretical temperature at the front end of the radiator according to the equivalent temperature rise of the intercooler and an ambient temperature; and obtaining a hot air backflow temperature based on a difference between the actual temperature and the theoretical temperature. The method can quantitatively evaluate the influence degree of the hot air backflow phenomenon of the engine compartment on the air inlet temperature at the front end of the heat dissipation component.

Description

Technical Field

[0001] This application relates to the field of computational fluid dynamics technology, and in particular to a method, apparatus, computer equipment, storage medium, and computer program product for evaluating hot air recirculation in an engine compartment. Background Technology

[0002] During vehicle operation, natural air is drawn into the engine compartment through the air intake grille by the fan. After passing through cooling components such as the intercooler and radiator, it is heated by carrying away heat from the coolant. When this heated air is blown towards the engine by the fan, some of it is obstructed by the engine and cannot escape from the rear of the engine compartment. Instead, it flows back to the front of the cooling components, creating a hot air recirculation phenomenon within the engine compartment. This hot air recirculation not only increases the intake air temperature at the front of the cooling components, reducing their heat dissipation performance, but also lowers the vehicle's allowable ambient temperature. The allowable ambient temperature (Tapr) is the highest ambient temperature at which the vehicle can operate normally due to temperature limitations.

[0003] Traditional technologies for vehicle thermal management analysis mostly focus on aspects such as intake air temperature rise, passenger thermal comfort, or intake air volume, rarely assessing the impact of hot air recirculation. However, effectively assessing the impact of hot air recirculation is crucial for improving hot air recirculation issues in vehicles. Therefore, there is an urgent need to provide a method for effectively evaluating hot air recirculation. Summary of the Invention

[0004] Therefore, it is necessary to provide a method, apparatus, computer equipment, computer-readable storage medium, and computer program product for evaluating hot air recirculation in an engine compartment, which can effectively assess the hot air recirculation in the engine compartment, in response to the above-mentioned technical problems.

[0005] Firstly, this application provides a method for evaluating hot air recirculation in an engine compartment. The method includes:

[0006] Acquire simulation and test data of the vehicle engine compartment under the target operating conditions; the simulation data includes the frontal projected area of ​​the intercooler, the frontal projected area of ​​the radiator, the air intake of the intercooler, and the actual temperature at the front end of the radiator; the test data includes the heat dissipation of the intercooler.

[0007] The temperature rise of the intercooler is determined based on its heat dissipation and air intake.

[0008] Based on the front projected area of ​​the intercooler, the front projected area of ​​the radiator, and the temperature rise of the intercooler, determine the equivalent temperature rise corresponding to the temperature rise of the intercooler.

[0009] The theoretical temperature of the radiator front end is determined based on the equivalent temperature rise of the intercooler and the ambient temperature.

[0010] The hot air recirculation temperature is obtained based on the difference between the actual temperature and the theoretical temperature at the front end of the radiator. The hot air recirculation temperature is used to characterize the degree of influence of hot air recirculation on the inlet air temperature at the front end of the radiator.

[0011] In one embodiment, the simulation data also includes the air intake volume of the radiator, and the test data also includes the allowable ambient temperature for testing; the method further includes determining the allowable ambient temperature of the vehicle based on the air intake volume of the radiator; obtaining a correction value for the allowable ambient temperature of the vehicle based on the difference between the allowable ambient temperature of the vehicle and the hot air return temperature; and determining the degree of agreement between the correction value and the allowable ambient temperature for testing based on the magnitude of the correction value and the allowable ambient temperature for testing.

[0012] In one embodiment, a condenser is arranged in the vehicle's engine compartment, and the condenser is positioned in front of the intercooler. The simulation data also includes the frontal projected area of ​​the condenser and the air intake volume of the condenser; the experimental data also includes the heat dissipation of the condenser; the theoretical temperature of the radiator front end is determined based on the equivalent temperature rise of the intercooler and the ambient temperature, including determining the temperature rise of the condenser based on the heat dissipation of the condenser and the air intake volume of the condenser; determining the equivalent temperature rise corresponding to the temperature rise of the condenser based on the frontal projected area of ​​the condenser, the frontal projected area of ​​the radiator, and the temperature rise of the condenser; and determining the theoretical temperature of the radiator front end based on the equivalent temperature rise of the condenser, the equivalent temperature rise of the intercooler, and the ambient temperature.

[0013] In one embodiment, simulation data of the vehicle engine compartment under the target operating condition is obtained, including building a three-dimensional vehicle model, dividing the computational domain of the three-dimensional vehicle model into a volume mesh to obtain a meshed vehicle computational domain; the three-dimensional vehicle model includes heat dissipation components, a fan, and an engine, the heat dissipation components include a condenser, an intercooler, and a radiator, wherein the intercooler is arranged in front of the radiator, the radiator is arranged in front of the fan, and the fan is arranged in front of the engine; local coordinate systems are established corresponding to the porous media regions of the condenser, the intercooler, the radiator, and the rotational domain of the fan; based on the meshed vehicle computational domain, boundary surfaces are established corresponding to the porous media regions of the condenser, the intercooler, the radiator, and the fan; based on each local coordinate system and each boundary surface, the vehicle computational model is determined; based on the vehicle computational model, thermal balance simulation calculations are performed to obtain multiple simulation data.

[0014] In one embodiment, the method further includes obtaining a streamline development state diagram and a heat dissipation component temperature cloud map within the engine compartment based on multiple simulation data; the streamline development state diagram within the engine compartment includes hot air streamlines, which characterize the recirculated hot air that flows back from the rear of the heat dissipation component to the front of the heat dissipation component after being heated by the heat dissipation component; the heat dissipation component temperature cloud map includes a temperature cloud map of the intercooler and a temperature cloud map of the radiator; and the degree of influence of the recirculated hot air on the heat dissipation performance of the heat dissipation component is evaluated based on the streamline development state diagram and the heat dissipation component temperature cloud map within the engine compartment.

[0015] In one embodiment, the impact of recirculating hot air on the heat dissipation performance of the heat dissipation components is evaluated based on the streamline development diagram within the engine compartment and the temperature cloud map of the heat dissipation components. This includes determining the airflow rate of the recirculating hot air around the heat dissipation components based on the density of the hot air streamlines; determining a first temperature value of the recirculating hot air around the heat dissipation components based on the spectral color of the hot air streamlines; determining a second temperature value of the recirculating hot air returning to the front of the intercooler and the front of the radiator based on the spectral color of each region in the temperature cloud map of the intercooler and the temperature cloud map of the radiator, respectively; and evaluating the impact of the recirculating hot air on the heat dissipation performance of the heat dissipation components based on at least one of the airflow rate, the first temperature value, or the second temperature value.

[0016] Secondly, this application also provides a hot air recirculation assessment device for an engine compartment. The device includes:

[0017] The acquisition module is used to acquire simulation data and test data of the vehicle engine compartment under the target working conditions. The simulation data includes the front projection area of ​​the intercooler, the front projection area of ​​the radiator, the air intake of the intercooler, and the actual temperature of the front end of the radiator. The test data includes the heat dissipation of the intercooler.

[0018] The determination module is used to determine the temperature rise of the intercooler based on its heat dissipation and air intake.

[0019] The determination module is also used to determine the equivalent temperature rise corresponding to the temperature rise of the intercooler based on the front projected area of ​​the intercooler, the front projected area of ​​the radiator, and the temperature rise of the intercooler.

[0020] The determination module is also used to determine the theoretical temperature of the front end of the radiator based on the equivalent temperature rise of the intercooler and the ambient temperature.

[0021] The determination module is also used to obtain the hot air recirculation temperature based on the difference between the actual temperature and the theoretical temperature at the front end of the radiator. The hot air recirculation temperature is used to characterize the degree of influence of hot air recirculation on the inlet air temperature at the front end of the radiator.

[0022] Thirdly, this application also provides a computer device. The computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to perform the following steps:

[0023] Acquire simulation and test data of the vehicle engine compartment under the target operating conditions; the simulation data includes the frontal projected area of ​​the intercooler, the frontal projected area of ​​the radiator, the air intake of the intercooler, and the actual temperature at the front end of the radiator; the test data includes the heat dissipation of the intercooler.

[0024] The temperature rise of the intercooler is determined based on its heat dissipation and air intake.

[0025] Based on the front projected area of ​​the intercooler, the front projected area of ​​the radiator, and the temperature rise of the intercooler, determine the equivalent temperature rise corresponding to the temperature rise of the intercooler.

[0026] The theoretical temperature of the radiator front end is determined based on the equivalent temperature rise of the intercooler and the ambient temperature.

[0027] The hot air recirculation temperature is obtained based on the difference between the actual temperature and the theoretical temperature at the front end of the radiator. The hot air recirculation temperature is used to characterize the degree of influence of hot air recirculation on the inlet air temperature at the front end of the radiator.

[0028] Fourthly, this application also provides a computer-readable storage medium. This computer-readable storage medium stores a computer program thereon, which, when executed by a processor, performs the following steps:

[0029] Acquire simulation and test data of the vehicle engine compartment under the target operating conditions; the simulation data includes the frontal projected area of ​​the intercooler, the frontal projected area of ​​the radiator, the air intake of the intercooler, and the actual temperature at the front end of the radiator; the test data includes the heat dissipation of the intercooler.

[0030] The temperature rise of the intercooler is determined based on its heat dissipation and air intake.

[0031] Based on the front projected area of ​​the intercooler, the front projected area of ​​the radiator, and the temperature rise of the intercooler, determine the equivalent temperature rise corresponding to the temperature rise of the intercooler.

[0032] The theoretical temperature of the radiator front end is determined based on the equivalent temperature rise of the intercooler and the ambient temperature.

[0033] The hot air recirculation temperature is obtained based on the difference between the actual temperature and the theoretical temperature at the front end of the radiator. The hot air recirculation temperature is used to characterize the degree of influence of hot air recirculation on the inlet air temperature at the front end of the radiator.

[0034] Fifthly, this application also provides a computer program product. This computer program product includes a computer program that, when executed by a processor, performs the following steps:

[0035] Acquire simulation and test data of the vehicle engine compartment under the target operating conditions; the simulation data includes the frontal projected area of ​​the intercooler, the frontal projected area of ​​the radiator, the air intake of the intercooler, and the actual temperature at the front end of the radiator; the test data includes the heat dissipation of the intercooler.

[0036] The temperature rise of the intercooler is determined based on its heat dissipation and air intake.

[0037] Based on the front projected area of ​​the intercooler, the front projected area of ​​the radiator, and the temperature rise of the intercooler, determine the equivalent temperature rise corresponding to the temperature rise of the intercooler.

[0038] The theoretical temperature of the radiator front end is determined based on the equivalent temperature rise of the intercooler and the ambient temperature.

[0039] The hot air recirculation temperature is obtained based on the difference between the actual temperature and the theoretical temperature at the front end of the radiator. The hot air recirculation temperature is used to characterize the degree of influence of hot air recirculation on the inlet air temperature at the front end of the radiator.

[0040] The aforementioned engine compartment hot air recirculation assessment method, device, computer equipment, storage medium, and computer program product acquire simulation data and test data of the vehicle engine compartment under target operating conditions. The simulation data includes the frontal projected area of ​​the intercooler, the frontal projected area of ​​the radiator, the air intake of the intercooler, and the actual temperature at the front end of the radiator. The test data includes the heat dissipation of the intercooler. Based on the heat dissipation and air intake of the intercooler, the temperature rise of the intercooler is determined. Based on the frontal projected area of ​​the intercooler, the frontal projected area of ​​the radiator, and the temperature rise of the intercooler, the equivalent temperature rise corresponding to the temperature rise of the intercooler is determined. Based on the equivalent temperature rise of the intercooler... Based on the ambient temperature, the theoretical temperature of the radiator front end is determined. The hot air recirculation temperature is obtained based on the difference between the actual and theoretical temperatures of the radiator front end. This hot air recirculation temperature characterizes the impact of hot air recirculation on the intake air temperature of the radiator front end. Therefore, the hot air recirculation temperature can quantitatively assess the impact of hot air recirculation on the intake air temperature of the radiator front end. Furthermore, the hot air recirculation temperature also characterizes the impact of hot air recirculation on the intake air temperature of the heat dissipation components. Thus, the hot air recirculation temperature achieves the purpose of quantitatively and effectively assessing the impact of hot air recirculation in the engine compartment on the intake air temperature of the heat dissipation components. Attached Figure Description

[0041] Figure 1 This is a diagram illustrating the application environment of a hot air recirculation assessment method for the engine compartment in one embodiment.

[0042] Figure 2 This is a flowchart illustrating a method for evaluating hot air recirculation in an engine compartment in one embodiment.

[0043] Figure 3This is a flowchart illustrating the steps for obtaining the correction value of the allowable ambient temperature of the whole vehicle in one embodiment.

[0044] Figure 4 This is a flowchart illustrating the steps for obtaining simulation data in one embodiment;

[0045] Figure 5 This is a structural schematic diagram of a three-dimensional vehicle model in one embodiment;

[0046] Figure 6 This is a schematic diagram of the streamlined development state within the engine compartment in one embodiment;

[0047] Figure 7A This is a schematic diagram of the temperature cloud map of the entire vehicle cross-section in one embodiment;

[0048] Figure 7B This is a schematic diagram of the temperature cloud map of the heat dissipation component in one embodiment;

[0049] Figure 8 This is a flowchart illustrating the hot air recirculation assessment method for the engine compartment in another embodiment;

[0050] Figure 9 This is a flowchart illustrating the data extraction and hot air recirculation evaluation calculation steps in one embodiment;

[0051] Figure 10 This is a structural block diagram of a hot air recirculation assessment device for an engine compartment in one embodiment.

[0052] Figure 11 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0054] The engine compartment hot air recirculation assessment method provided in this application embodiment can be applied to, for example... Figure 1 In the application environment shown, terminal 102 communicates with server 104 via a network. A data storage system can store the data that server 104 needs to process. The data storage system can be integrated onto server 104 or placed in the cloud or on other network servers. Terminal 102 can independently execute the engine compartment hot air recirculation assessment method provided in this application embodiment, and terminal 102 and server 104 can also collaboratively execute the engine compartment hot air recirculation assessment method provided in this application embodiment.

[0055] When terminal 102 executes the hot air recirculation evaluation method for the engine compartment alone, terminal 102 acquires simulation data and test data of the vehicle engine compartment under the target operating condition. The simulation data includes the frontal projected area of ​​the intercooler, the frontal projected area of ​​the radiator, the air intake of the intercooler, and the actual temperature of the radiator front end. The test data includes the heat dissipation of the intercooler. Based on the heat dissipation and air intake of the intercooler, the temperature rise of the intercooler is determined. Based on the frontal projected area of ​​the intercooler, the frontal projected area of ​​the radiator, and the temperature rise of the intercooler, the equivalent temperature rise corresponding to the temperature rise of the intercooler is determined. Based on the equivalent temperature rise of the intercooler and the ambient temperature, the theoretical temperature of the radiator front end is determined. Based on the difference between the actual temperature and the theoretical temperature of the radiator front end, the hot air recirculation temperature is obtained. The hot air recirculation temperature is used to characterize the degree of influence of hot air recirculation on the air intake temperature of the radiator front end.

[0056] When terminal 102 and server 104 collaboratively execute the hot air recirculation evaluation method for the engine compartment, the terminal acquires simulation data and test data of the vehicle's engine compartment under the target operating condition. The simulation data includes the frontal projected area of ​​the intercooler, the frontal projected area of ​​the radiator, the air intake of the intercooler, and the actual temperature of the radiator front end. The test data includes the heat dissipation of the intercooler. The terminal then sends the simulation data and test data to server 104. Server 104 determines the temperature rise of the intercooler based on its heat dissipation and air intake. Based on the frontal projected area of ​​the intercooler, the frontal projected area of ​​the radiator, and the temperature rise of the intercooler, server 104 determines the equivalent temperature rise corresponding to the temperature rise of the intercooler. Based on the equivalent temperature rise of the intercooler and the ambient temperature, server 104 determines the theoretical temperature of the radiator front end. Based on the difference between the actual temperature and the theoretical temperature of the radiator front end, server 104 obtains the hot air recirculation temperature, which characterizes the degree of influence of hot air recirculation on the air intake temperature of the radiator front end.

[0057] The terminal 102 can be, but is not limited to, various personal computers, laptops, smartphones, tablets, IoT devices, and portable wearable devices. IoT devices can include smart speakers, smart TVs, smart air conditioners, and smart in-vehicle systems. Portable wearable devices can include smartwatches, smart bracelets, and head-mounted devices. The server 104 can be implemented using a standalone server or a server cluster consisting of multiple servers.

[0058] In one embodiment, such as Figure 2 As shown, a method for evaluating hot air recirculation in an engine compartment is provided. This method can be executed independently by a terminal or server, or collaboratively by both. This method is applied to... Figure 1 Taking terminal 102 as an example, the explanation includes the following steps:

[0059] Step 202: Obtain simulation data and test data of the vehicle engine compartment under the target operating conditions; the simulation data includes the frontal projected area of ​​the intercooler, the frontal projected area of ​​the radiator, the air intake of the intercooler, and the actual temperature at the front end of the radiator; the test data includes the heat dissipation of the intercooler.

[0060] The target operating condition refers to a condition where the vehicle experiences hot air recirculation at a preset ambient temperature, including both driving and idling states. The preset ambient temperature is set according to testing requirements, for example, it could be 30°C; this embodiment does not limit this setting. The vehicle engine compartment includes a cooling component and an engine located behind the cooling component. The cooling component includes at least an intercooler and a radiator, with the intercooler located in front of the radiator.

[0061] Simulation data is obtained through numerical simulation of the flow and temperature fields within the engine compartment using Computational Fluid Dynamics (CFD) simulation software. This data is used to analyze hot air flow and heat dissipation within the engine compartment. Common CFD simulation software for commercial vehicle thermal management analysis includes FLUENT, Stat CD, STAR-CCM+, KUIL, and GT-COOL. FLUENT is a general-purpose CFD software package used to simulate complex flows ranging from incompressible to highly compressible. Stat CD, developed by Computational Dynamics, is the world's first commercial fluid analysis software package to employ fully unstructured mesh generation technology and the finite volume method to study complex flows in industrial applications. STAR-CCM+ is a next-generation CFD solver developed by CD-adapco using computational continuum mechanics algorithms. GT-COOL is an important component of the GT-SUITE software series. GT-SUITE covers aspects such as the engine, drive system, cooling system, and fuel supply system, and is a one-dimensional fluid model.

[0062] The test data is obtained by conducting thermal balance tests on the engine using a test bench in the test chamber. The engine thermal balance test analyzes the destination of the total heat generated by the combustion of fuel entering the engine. There are five destinations of the total heat: heat converted into effective power, heat discharged from the exhaust, heat carried away by the coolant (i.e., the heat dissipation of the radiator), heat carried away by the intercooler (i.e., the heat dissipation of the intercooler), and residual heat.

[0063] For example, the terminal acquires simulation data and test data of the vehicle engine compartment under the target operating conditions; the simulation data includes the front projection area of ​​the intercooler, the front projection area of ​​the radiator, the air intake of the intercooler and the actual temperature of the front end of the radiator, and the test data includes the heat dissipation of the intercooler.

[0064] Step 204: Determine the temperature rise of the intercooler based on its heat dissipation and air intake.

[0065] The temperature rise of the intercooler is the increase in temperature after the intercooler absorbs heat from the intercooler, which is calculated using the specific heat capacity formula.

[0066] The formula for specific heat capacity is:

[0067]

[0068] Where Q is heat, m is the mass of the object, and c is the mass of the object. p，c It is the specific heat capacity of the object. The specific heat capacity of air is a constant related to the ambient temperature; for example, at an ambient temperature of 25°C, c p，c It is 1.04 J / (kg·℃).

[0069] For example, the terminal calculates the temperature rise of the intercooler based on the formulas for the intercooler's heat dissipation, air intake, and specific heat capacity.

[0070] Step 206: Determine the equivalent temperature rise corresponding to the temperature rise of the intercooler based on the front projected area of ​​the intercooler, the front projected area of ​​the radiator, and the temperature rise of the intercooler.

[0071] The equivalent temperature rise corresponding to the intercooler's temperature rise is the temperature rise of the intercooler after absorbing the heat dissipation of the intercooler, which is then applied to the radiator. It is used to characterize the temperature rise of the radiator after absorbing the heat dissipation of the intercooler. The ratio of the frontal projected area of ​​the intercooler to the frontal projected area of ​​the radiator is equal to the ratio of the equivalent temperature rise corresponding to the intercooler's temperature rise to the actual temperature rise of the intercooler.

[0072] For example, the terminal determines the ratio of the front projected area of ​​the intercooler to the front projected area of ​​the radiator, and determines the equivalent temperature rise corresponding to the temperature rise of the intercooler based on the product of the ratio and the temperature rise of the intercooler.

[0073] Step 208: Determine the theoretical temperature of the front end of the radiator based on the equivalent temperature rise of the intercooler and the ambient temperature.

[0074] The theoretical temperature at the front of the radiator is the intake air temperature without considering hot air recirculation. Due to hot air recirculation, some hot air flows back to the front of the radiator, causing the intake air temperature at the front to rise. Therefore, the intake air temperature at the front of the radiator without considering hot air recirculation is lower than the intake air temperature with considering hot air recirculation; in other words, the theoretical temperature at the front of the radiator is lower than the actual temperature.

[0075] For example, the terminal uses the sum of the equivalent temperature rise of the intercooler and the ambient temperature as the theoretical temperature of the radiator front end.

[0076] Step 210: Based on the difference between the actual temperature and the theoretical temperature at the front end of the radiator, the hot air recirculation temperature is obtained. The hot air recirculation temperature is used to characterize the degree of influence of hot air recirculation on the inlet air temperature at the front end of the radiator.

[0077] Among them, the hot air recirculation temperature is the temperature value at which the intake air temperature at the front end of the radiator rises due to the hot air recirculation to the front end of the intercooler and radiator. It is used to quantitatively characterize the degree of influence of hot air recirculation on the intake air temperature at the front end of the radiator.

[0078] For example, the terminal uses the difference between the actual temperature and the theoretical temperature at the front end of the radiator as the hot air recirculation temperature. During the hot air recirculation process, hot air passes through the intercooler and blows towards the radiator, causing the intake air temperature at the front end of the radiator to rise. Furthermore, the equivalent temperature rise corresponding to the intercooler's temperature rise characterizes the temperature rise of the radiator after absorbing the heat dissipation from the intercooler. In addition, the radiator is closer to the engine and is more affected by the hot air recirculation than the intercooler. Therefore, the hot air recirculation temperature is also used to characterize the degree of influence of the hot air recirculation on the intake air temperature at the front end of the heat dissipation components.

[0079] The aforementioned method for evaluating hot air recirculation in the engine compartment involves acquiring simulation and experimental data of the vehicle's engine compartment under target operating conditions. The simulation data includes the frontal projected area of ​​the intercooler, the frontal projected area of ​​the radiator, the airflow into the intercooler, and the actual temperature at the front end of the radiator. The experimental data includes the heat dissipation of the intercooler. Based on the heat dissipation and airflow of the intercooler, the temperature rise of the intercooler is determined. Based on the frontal projected area of ​​the intercooler, the frontal projected area of ​​the radiator, and the temperature rise of the intercooler, the equivalent temperature rise corresponding to the temperature rise of the intercooler is determined. Based on the equivalent temperature rise of the intercooler and the ambient temperature, the radiator... The theoretical temperature at the front end; based on the difference between the actual temperature and the theoretical temperature at the front end of the radiator, the hot air recirculation temperature is obtained. The hot air recirculation temperature is used to characterize the degree of influence of hot air recirculation on the intake air temperature at the front end of the radiator. Thus, the hot air recirculation temperature can be used to quantitatively assess the degree of influence of hot air recirculation on the intake air temperature at the front end of the radiator. Furthermore, the hot air recirculation temperature is also used to characterize the degree of influence of hot air recirculation on the intake air temperature at the front end of the heat dissipation components. Therefore, the hot air recirculation temperature can be used to quantitatively and effectively assess the degree of influence of hot air recirculation in the engine compartment on the intake air temperature at the front end of the heat dissipation components.

[0080] In one embodiment, such as Figure 3 As shown, the simulation data also includes the radiator's air intake volume, and the test data includes the allowable ambient temperature; the hot air recirculation evaluation method for this engine compartment also includes:

[0081] Step 302: Determine the permissible ambient temperature of the vehicle based on the air intake of the radiator.

[0082] Among them, the permissible ambient temperature of the whole vehicle is the highest ambient temperature at which the vehicle can work normally without considering hot air recirculation.

[0083] For example, the terminal calculates the permissible ambient temperature of the vehicle based on the air intake of the radiator using a mathematical model, such as a mathematical model in MATLAB software.

[0084] Step 304: Based on the difference between the allowable ambient temperature of the vehicle and the hot air recirculation temperature, obtain the correction value of the allowable ambient temperature of the vehicle.

[0085] Among them, the correction value for the allowable ambient temperature of the whole vehicle is the highest ambient temperature at which the vehicle can work normally, taking into account the hot air recirculation. It is used to characterize the degree of influence of hot air recirculation on the allowable ambient temperature of the whole vehicle.

[0086] For example, the terminal uses the difference between the vehicle's allowable ambient temperature and the hot air recirculation temperature as a correction value for the vehicle's allowable ambient temperature.

[0087] Step 306: Determine the degree of agreement between the correction value and the allowable ambient temperature based on the magnitude of the correction value and the allowable ambient temperature.

[0088] The permissible ambient temperature is the highest ambient temperature at which the vehicle can operate normally when the engine undergoes a thermal balance test on a test bench within the test chamber. The degree of agreement characterizes the matching degree between the correction value of the vehicle's permissible ambient temperature and the permissible ambient temperature in the test. Furthermore, the smaller the absolute value of the difference between the correction value and the permissible ambient temperature, the closer the simulation result (i.e., the correction value) is to the experimental result (i.e., the permissible ambient temperature in the test).

[0089] For example, the terminal compares the correction value of the vehicle's permissible ambient temperature with the test permissible ambient temperature. If the difference between the correction value and the test permissible ambient temperature is less than a preset difference, it is determined that the correction value and the test permissible ambient temperature have a high degree of agreement. Thus, when the agreement between the correction value and the test permissible ambient temperature is high, that is, when the accuracy of the simulation results is high, the correction value obtained by simulation calculation can be used to replace the test permissible ambient temperature obtained by conducting a thermal balance test in the test chamber. In other words, when it is necessary to determine the highest ambient temperature at which the vehicle can operate normally considering hot air recirculation, it is not necessary to conduct a thermal balance test in the test chamber. Instead, the permissible ambient temperature of the vehicle considering hot air recirculation can be determined by numerically simulating the flow field and temperature field in the engine compartment using CFD simulation software and calculating the simulation data.

[0090] In this embodiment, after obtaining the hot air recirculation temperature, the permissible ambient temperature of the vehicle is determined based on the radiator's airflow rate in the simulation data. A correction value for the vehicle's permissible ambient temperature is obtained based on the difference between the permissible ambient temperature and the hot air recirculation temperature, thereby achieving the purpose of assessing the impact of the hot air recirculation phenomenon on the vehicle's permissible ambient temperature. After obtaining the correction value for the vehicle's permissible ambient temperature, the degree of agreement between the correction value and the experimental permissible ambient temperature in the experimental data is determined, thereby assessing the agreement between the simulation results and the experimental results. When the agreement between the simulation results and the experimental results is high, i.e., when the simulation results are close to the experimental results, the simulation results can be used to replace the experimental results. In this case, the permissible ambient temperature of the vehicle considering hot air recirculation can be obtained without conducting experiments, thus also achieving the goal of reducing experimental costs.

[0091] In one embodiment, a condenser is arranged in the vehicle engine compartment, and the condenser is positioned in front of the intercooler. The simulation data also includes the frontal projected area of ​​the condenser and the air intake volume of the condenser; the experimental data also includes the heat dissipation of the condenser; the theoretical temperature of the radiator front end is determined based on the equivalent temperature rise of the intercooler and the ambient temperature, including determining the temperature rise of the condenser based on the heat dissipation of the condenser and the air intake volume of the condenser; determining the equivalent temperature rise corresponding to the temperature rise of the condenser based on the frontal projected area of ​​the condenser, the frontal projected area of ​​the radiator, and the temperature rise of the condenser; and determining the theoretical temperature of the radiator front end based on the equivalent temperature rise of the condenser, the equivalent temperature rise of the intercooler, and the ambient temperature.

[0092] The condenser temperature rise is the increase in temperature after the condenser absorbs heat from the vehicle's built-in air conditioning system, calculated using the specific heat capacity formula. The equivalent temperature rise corresponding to the condenser's temperature rise is applied to the radiator after the condenser absorbs heat from the air conditioning system, representing the radiator's temperature rise after absorbing heat from the air conditioning system. The ratio of the condenser's frontal projected area to the radiator's frontal projected area is equal to the ratio of the equivalent temperature rise corresponding to the condenser's temperature rise to the condenser's actual temperature rise.

[0093] For example, the terminal calculates the temperature rise of the condenser based on the heat dissipation of the condenser, the air intake of the condenser, and the specific heat capacity formula; determines the ratio of the front projected area of ​​the condenser to the front projected area of ​​the radiator, and determines the equivalent temperature rise corresponding to the temperature rise of the condenser based on the product of this ratio and the temperature rise of the condenser; and takes the sum of the equivalent temperature rise of the condenser, the equivalent temperature rise of the intercooler, and the ambient temperature as the theoretical temperature at the front end of the radiator.

[0094] In this embodiment, the temperature rise of the condenser is determined based on the heat dissipation and air intake of the condenser; the equivalent temperature rise corresponding to the temperature rise of the condenser is determined based on the front projected area of ​​the condenser, the front projected area of ​​the radiator, and the temperature rise of the condenser; and the theoretical temperature of the front end of the radiator is determined based on the equivalent temperature rise of the condenser, the equivalent temperature rise of the intercooler, and the ambient temperature. This achieves the goal of determining the theoretical temperature of the front end of the radiator even when a condenser is also arranged in the vehicle's engine compartment, i.e., when the heat dissipation components include the condenser, intercooler, and radiator.

[0095] In one embodiment, such as Figure 4 As shown, simulation data of the vehicle engine compartment under the target operating condition is obtained, including:

[0096] Step 402: Build a three-dimensional vehicle model and perform volume meshing on the computational domain of the three-dimensional vehicle model to obtain a meshed vehicle computational domain. The three-dimensional vehicle model includes heat dissipation components, a fan, and an engine. The heat dissipation components include a condenser, an intercooler, and a radiator. The intercooler is located in front of the radiator, the radiator is located in front of the fan, and the fan is located in front of the engine.

[0097] Among them, the three-dimensional vehicle model is a vehicle model built using CFD simulation software, such as... Figure 5 As shown, the three-dimensional vehicle model includes a cab, cooling components, a fan, an engine, a chassis, and a cargo box. The cooling components include a condenser, an intercooler, and a radiator. The intercooler is located in front of the radiator, the radiator is located in front of the fan, the fan is located in front of the engine, and the condenser can be located in front of the intercooler or in other locations.

[0098] The engine generates heat during the process of converting fuel into mechanical energy. To prevent the engine from overheating, the hot coolant flowing out of the engine passes through the cooling components. The cooling components draw in natural air, which carries away the heat from the coolant. The cooled coolant then flows back into the engine, thus controlling the engine temperature within a reasonable range.

[0099] For example, the terminal builds a three-dimensional vehicle model, determines the computational domain of the three-dimensional vehicle model, and divides the computational domain of the three-dimensional vehicle model into a volume mesh to obtain a meshed vehicle computational domain.

[0100] Step 404: Establish local coordinate systems corresponding to the porous media region of the condenser, the porous media region of the intercooler, the porous media region of the radiator, and the rotation domain of the fan.

[0101] For example, the terminal sets the region type of the condenser, intercooler, and radiator to porous media region, and sets the fan rotation domain and the vehicle computing domain to fluid region. For the porous media region of the condenser, the porous media region of the intercooler, and the porous media region of the radiator, the terminal establishes their respective local coordinate systems based on the Cartesian coordinate system; for the fan rotation domain, the terminal establishes the corresponding local coordinate system based on the cylindrical coordinate system.

[0102] Step 406: Based on the gridded vehicle computational domain, establish the boundary surfaces corresponding to the porous media region of the condenser, the porous media region of the intercooler, the porous media region of the radiator, and the rotation domain of the fan.

[0103] Among them, the boundary surface, or interface, is one of the boundary conditions defined in the vehicle calculation model. Interfaces exist in pairs, used for data exchange between two contacting boundaries during simulation. The boundary surfaces corresponding to the porous media region of the condenser include a set of boundary surfaces corresponding to the inlet boundary and an outlet boundary of the porous media region of the condenser; the boundary surfaces corresponding to the porous media region of the intercooler include a set of boundary surfaces corresponding to the inlet boundary and an outlet boundary of the porous media region of the intercooler; the boundary surfaces corresponding to the porous media region of the radiator include a set of boundary surfaces corresponding to the inlet boundary and an outlet boundary of the porous media region of the radiator; the boundary surfaces corresponding to the fan's rotation domain include a set of boundary surfaces corresponding to the inlet boundary, an outlet boundary, and the surrounding boundary of the fan's rotation domain.

[0104] For example, the terminal selects the inlet boundary of the porous medium region of the condenser and the inlet boundary of the condenser core of the fluid region of the vehicle to establish a set of boundary surfaces corresponding to the inlet boundary of the porous medium region of the condenser; and selects the outlet boundary of the porous medium region of the condenser and the outlet boundary of the condenser core of the fluid region of the vehicle to establish a set of boundary surfaces corresponding to the outlet boundary of the porous medium region of the condenser.

[0105] Select the inlet boundary of the porous medium region of the intercooler and the inlet boundary of the intercooler core in the fluid region of the vehicle, and establish a set of boundary surfaces corresponding to the inlet boundary of the porous medium region of the intercooler; select the outlet boundary of the porous medium region of the intercooler and the outlet boundary of the intercooler core in the fluid region of the vehicle, and establish a set of boundary surfaces corresponding to the outlet boundary of the porous medium region of the intercooler.

[0106] Select the inlet boundary of the porous medium region of the radiator and the inlet boundary of the radiator core in the fluid region of the whole vehicle, and establish a set of boundary surfaces corresponding to the inlet boundary of the porous medium region of the radiator; select the outlet boundary of the porous medium region of the radiator and the outlet boundary of the radiator core in the fluid region of the whole vehicle, and establish a set of boundary surfaces corresponding to the outlet boundary of the porous medium region of the radiator.

[0107] Select the inlet boundary of the fan's fluid region and the inlet boundary of the fan in the fluid region of the whole vehicle, and establish a set of boundary surfaces corresponding to the inlet boundary of the fan's rotation domain; select the outlet boundary of the fan's fluid region and the outlet boundary of the fan in the fluid region of the whole vehicle, and establish a set of boundary surfaces corresponding to the outlet boundary of the fan's rotation domain; select the surrounding boundary of the fan's fluid region and the surrounding boundary of the fan in the fluid region of the whole vehicle, and establish a set of boundary surfaces corresponding to the surrounding boundary of the fan's rotation domain.

[0108] Step 408: Determine the vehicle calculation model based on each local coordinate system and each boundary surface.

[0109] The vehicle's computational model is a three-dimensional geometric model.

[0110] For example, the terminal determines the whole vehicle calculation model based on the local coordinate systems and boundary surfaces corresponding to the porous media regions of the condenser, the intercooler, the radiator, and the rotation domain of the fan.

[0111] Step 410: Perform thermal balance simulation calculations based on the vehicle calculation model to obtain multiple simulation data.

[0112] For example, the terminal performs thermal balance simulation calculations based on the vehicle calculation model, obtaining multiple simulation data. It then determines whether each simulation data point has converged. If at least one simulation data point converges, the terminal performs image visualization processing on the multiple simulation results, outputting a streamline development diagram of the engine compartment and a temperature cloud map of the heat dissipation components. The conditions for determining whether the simulation data has converged include: the simulation data no longer changes or the change is less than a preset value within a preset time period; or, except for the energy residual curve, the other iterative residual curves are below 10. -3 The energy residual curve is below 10. -6 .

[0113] In this embodiment, a three-dimensional vehicle model is built, and local coordinate systems and boundary surfaces corresponding to the porous medium region of the condenser, the porous medium region of the intercooler, the porous medium region of the radiator, and the rotation domain of the fan are established respectively, thereby determining the vehicle calculation model. Based on the vehicle calculation model, thermal balance simulation calculation is performed to obtain multiple simulation data, which can achieve the purpose of obtaining simulation data of the vehicle engine compartment under the target working condition.

[0114] In one embodiment, the hot air recirculation assessment method for the engine compartment further includes obtaining a streamline development state diagram and a heat dissipation component temperature cloud map within the engine compartment based on multiple simulation data. The streamline development state diagram within the engine compartment includes hot air streamlines, which characterize the recirculated hot air that flows back from the rear of the heat dissipation component to the front of the heat dissipation component after being heated by the heat dissipation component. The heat dissipation component temperature cloud map includes the temperature cloud map of the intercooler and the temperature cloud map of the radiator. Based on the streamline development state diagram and the heat dissipation component temperature cloud map within the engine compartment, the degree of influence of the recirculated hot air on the heat dissipation performance of the heat dissipation component is assessed.

[0115] The diagram showing the streamlined development within the engine compartment illustrates the flow of natural air entering the engine compartment and the recirculating hot air within it. Natural air enters from the front of the cooling components and blows towards the engine, where it is heated to form hot air. Due to the obstruction of the engine, some of this hot air flows back from the rear of the cooling components to the front; this portion of hot air is referred to as recirculating hot air.

[0116] like Figure 6 As shown, the streamline development diagram inside the engine compartment includes the cold air streamline (located in...). Figure 6 The darker lines in the lower left corner) and the hot air flow lines (located in...) Figure 6 The lighter-colored lines in the upper right corner represent the cold air flow lines, which are used to represent the natural air entering the heat dissipation component, and the hot air flow lines, which are used to represent the hot air that flows back from the back of the heat dissipation component to the front of the heat dissipation component after being heated by the heat dissipation component.

[0117] like Figure 7A As shown, the whole vehicle temperature cloud map (temperature cloud map of the whole vehicle cross-section) includes the temperature cloud map of components such as the cab, cooling components, fan, engine, chassis, and cargo box. The cooling components include the intercooler and radiator, with the intercooler located in front of the radiator, the radiator located in front of the fan, and the fan located in front of the engine. The whole vehicle temperature cloud map shows the overall temperature of the intercooler and radiator.

[0118] like Figure 7B As shown, the temperature cloud map of the heat dissipation components includes the temperature cloud map of the intercooler (located in...). Figure 7B The small rectangle on the top layer) and the temperature cloud map of the radiator (located in Figure 7B (The large rectangle at the bottom). The temperature cloud map of the heat dissipation components shows the temperature of various areas of the intercooler and radiator.

[0119] For example, the terminal obtains a streamline development state diagram, a vehicle temperature cloud diagram, and a heat dissipation component temperature cloud diagram based on multiple simulation data; and evaluates the impact of the recirculating hot air on the heat dissipation performance of the heat dissipation component based on the streamline development state diagram, the vehicle temperature cloud diagram, and the heat dissipation component temperature cloud diagram.

[0120] In this embodiment, by obtaining a streamline development diagram and a temperature cloud map of the heat dissipation components within the engine compartment using simulation data, it is possible to assess the impact of recirculated hot air on the heat dissipation performance of the heat dissipation components based on these diagrams. Therefore, in addition to quantitatively assessing the impact of hot air recirculation on the inlet air temperature at the front end of the heat dissipation components through the hot air recirculation temperature, the streamline development diagram and temperature cloud map of the heat dissipation components also allow for a direct observation of the hot air recirculation phenomenon within the engine compartment, further aiding in the assessment of the impact of recirculated hot air on the heat dissipation performance of the heat dissipation components.

[0121] In one embodiment, the impact of recirculating hot air on the heat dissipation performance of the heat dissipation components is assessed based on the streamline development diagram within the engine compartment and the temperature cloud map of the heat dissipation components. This includes determining the airflow rate of the recirculating hot air around the heat dissipation components based on the density of the hot air streamlines; determining a first temperature value of the recirculating hot air around the heat dissipation components based on the spectral color of the hot air streamlines; determining a second temperature value of the recirculating hot air returning to the front of the intercooler and the front of the radiator based on the spectral color of each region in the temperature cloud map of the intercooler and the temperature cloud map of the radiator, respectively; and assessing the impact of the recirculating hot air on the heat dissipation performance of the heat dissipation components based on at least one of the airflow rate, the first temperature value, or the second temperature value.

[0122] Among them, such as Figure 6 As shown in the diagram illustrating the streamline development within the engine compartment, the density of the hot air streamlines characterizes the volume of recirculating hot air. Specifically, denser hot air streamlines indicate a larger volume of recirculating hot air, while sparser streamlines indicate a smaller volume of recirculating hot air. Furthermore, Figure 6 The spectral color band below shows the first temperature value of the recirculating hot air, represented by the spectral color of the hot air streamline. The first temperature value is the temperature value of the recirculating hot air represented by the spectral color in the streamline development state diagram inside the engine compartment.

[0123] like Figure 7B As shown, for the temperature contour plot of the heat dissipation component, Figure 7B The spectral color band on the left shows the temperature cloud map of the intercooler and the radiator. The spectral colors of each region in the temperature cloud map represent the second temperature value of the recirculated hot air in front of the intercooler and the radiator. The second temperature value is the temperature value of the recirculated hot air represented by the spectral color in the temperature cloud map of the heat dissipation component.

[0124] For example, the terminal determines the airflow volume of the recirculated hot air around the heat dissipation component (including the left and right sides, top and bottom sides of the heat dissipation component) based on the density of the hot air flow lines; determines the first temperature value of the recirculated hot air around the heat dissipation component based on the spectral color of the hot air flow lines; and determines the second temperature value of the recirculated hot air returning to the front of the intercooler and the front of the heat dissipation component based on the spectral color of each region in the temperature cloud map of the intercooler and the temperature cloud map of the heat dissipation component, respectively.

[0125] In one embodiment, the terminal can assess the impact of the recirculating hot air on the left and right sides, top and bottom of the heat dissipation component, respectively, based on the airflow volume and a first temperature value, to determine the placement of the anti-backflow baffle. The anti-backflow baffle is used to prevent the recirculating hot air from flowing back from the rear of the heat dissipation component to the front. For example, as... Figure 6 As shown, the airflow values ​​of the recirculated hot air on the left, right, and bottom sides of the heat dissipation component are all less than the airflow value of the recirculated hot air on the top side. When the first temperature value of the recirculated hot air on the left, right, and bottom sides is less than the first temperature value of the recirculated hot air on the top side, the terminal can determine that the impact of the recirculated hot air on the left, right, and bottom sides of the heat dissipation component is less than its impact on the top side of the heat dissipation component. Therefore, an anti-backflow baffle can be installed on the top side of the heat dissipation component to reduce the impact of hot air recirculation on the inlet air temperature at the front end of the heat dissipation component.

[0126] In one embodiment, the terminal can assess the impact of the recirculated hot air on the intake air temperature of each area in front of the intercooler and the radiator based on a second temperature value of the recirculated hot air returning to the area in front of the intercooler and the radiator. For example, as Figure 7B As shown, the second temperature value of the recirculated hot air in the upper left corner area in front of the intercooler is higher than that in the lower right, upper right, and lower left corner areas. The second temperature value of the recirculated hot air in the lower area in front of the radiator is higher than that in the upper area. Therefore, the terminal can determine that the impact of the recirculated hot air on the upper left corner area in front of the intercooler and the lower area in front of the radiator is greater than its impact on other areas of the intercooler and radiator. Therefore, anti-backflow baffles can be installed in the upper left corner area in front of the intercooler and the lower area in front of the radiator to reduce the impact of hot air recirculation on the intake air temperature at the front of the heat dissipation components.

[0127] In this embodiment, the airflow rate and first temperature value of the recirculating hot air around the heat dissipation component are determined based on the density and spectral color of the hot air streamlines. The second temperature value of the recirculating hot air returning to the front of the intercooler and the front of the radiator is determined based on the spectral color of each region in the temperature cloud map of the intercooler and the radiator. The impact of the recirculating hot air on the heat dissipation performance of the heat dissipation component is evaluated based on at least one of the airflow rate, the first temperature value, or the second temperature value. This allows for the evaluation of the impact of the recirculating hot air on the heat dissipation performance of the heat dissipation component based on the streamline development diagram within the engine compartment and the temperature cloud map of the heat dissipation component.

[0128] In one embodiment, such as Figure 8 As shown, a method for evaluating hot air recirculation in the engine compartment is also provided. This method quantifies the hot air recirculation temperature value based on direct observation of the hot air recirculation phenomenon in the engine compartment, and further corrects the permissible ambient temperature value for the entire commercial vehicle to match the experimental value. The method includes the following steps:

[0129] S1. Perform CFD thermal balance simulation calculations, set up a local coordinate system and boundary surface (Interface surface), and obtain the streamline state of the commercial vehicle engine compartment (i.e., the streamline development state diagram in the engine compartment) and the temperature cloud map of the heat dissipation components.

[0130] S2. Extract data to obtain the effective area value (front projected area), air volume value (intake air volume), and temperature value (actual temperature at the front end of the radiator) of the heat dissipation component.

[0131] S3. Perform hot air recirculation assessment calculations to obtain the hot air recirculation temperature value (hot air recirculation temperature) and the vehicle's allowable ambient temperature correction value (the vehicle's allowable ambient temperature correction value).

[0132] Optionally, in step S1, CFD thermal balance simulation calculations are performed, specifically including the following steps:

[0133] Preprocessing: A 3D vehicle model is built to obtain a 3D geometric model. The computational domain volume mesh is generated to complete the model meshing process.

[0134] The first step in setting up the computational simulation is to select the steady-state calculation type, turbulence model, and region type, and then complete the selection and setting of calculation parameters.

[0135] Step 2 of the simulation setup: Establish a local coordinate system for the porous media regions of the condenser, intercooler, and radiator, as well as the fan rotation domain;

[0136] Step 3 of the simulation setup: Establish the Interface for the porous medium region of the condenser, intercooler, radiator, fan rotation domain, and the whole vehicle computational domain;

[0137] Post-processing of computational simulations: Obtaining the streamline development state (streamline development state diagram) and temperature cloud map of the heat dissipation components within the vehicle's engine compartment. Post-processing involves visualizing and outputting the results after submitting the calculations and obtaining the results.

[0138] Optionally, the preprocessing includes using the STAR-CCM+ software to perform volume mesh generation on the vehicle computational domain using a polyhedral mesh that has a small number of meshes, fast convergence speed, high computational accuracy, and is suitable for backflow problem analysis, thus completing the CFD preprocessing.

[0139] Optionally, the simulation settings are configured. Step one includes using the SST·k-ω turbulence model; the condenser, intercooler, and radiator regions are set to porous media regions, and the fan rotation domain and the whole vehicle computational domain are set to fluid regions.

[0140] Optionally, the second step of the simulation setup includes establishing a Cartesian coordinate system, named cac and rad respectively, and using the method of defining the coordinate system by three points on the plane to construct local coordinate systems for the porous medium regions of the condenser, intercooler, and radiator to obtain the frontal projected area of ​​the heat dissipation component; establishing a cylindrical coordinate system, named fan, and using the method of defining the coordinate system by three points on the circle to construct the local coordinate system of the fan rotation domain.

[0141] Optionally, step three of the calculation simulation setup includes establishing interface surfaces for the condenser inlet, condenser outlet, intercooler inlet, intercooler outlet, radiator inlet, and radiator outlet for data exchange; and establishing interface surfaces for the fan rotation domain inlet, fan rotation domain outlet, and fan rotation domain surrounding area for internal and external flow field data exchange.

[0142] Optionally, post-processing of the simulation includes performing thermal balance simulation calculations on the vehicle calculation model built above, and selecting the radiator inlet airflow value (radiator intake airflow) as the physical quantity (simulation data) being monitored. There are two conditions for the calculation convergence criterion, and either one needs to be met: (1) The monitored physical quantity is stable, no longer changes, or changes very little and can be ignored, that is, the difference between the monitored physical quantities in the two steps is less than 10. -3 2. Except for the energy residual curve, the residual curves of other iterative calculations are below 10. -3 The energy residual curve is below 10. -6In this embodiment, the maximum number of steps required to stop the calculation is set to 6000. When the calculation reaches 6000 steps, both of the above conditions are met.

[0143] After stabilization, post-processing is performed using STAR-CCM+. A new "streamline" component is created from the derived components, with the fan boundary selected as the seed component. The development state of the streamline within the engine compartment is obtained. The streamline is then selected in the geometric scene, and the field function is set to the temperature field, with the temperature display range set to 30-70℃. The newly created "streamline" component is selected, and the development state of the streamline within the engine compartment is displayed, resulting in the following: Figure 6 The diagram shows the streamlined development of the engine compartment.

[0144] Post-processing was performed using STAR-CCM+. A scalar field was created within the geometric scene, and a temperature field was selected as the field function. The temperature field display range was set to 30-70℃. The intercooler and radiator were selected as the components, and the temperature of each area of ​​the heat dissipation components was displayed, resulting in the following output: Figure 7B The temperature contour map of the heat dissipation component is shown.

[0145] Post-processing is performed using STAR-CCM+. A new component "planar section," i.e., the mid-section of the vehicle, is created within the derived components, with a normal vector of [0,1,0]. In the geometry scene, a scalar field is created, and the field function is selected as a temperature field. The temperature field display range is set to 30-70℃. The new component "planar section" is selected, and the temperature of the mid-section of the vehicle is displayed, resulting in the following... Figure 7A The image shows the temperature cloud map of the entire vehicle.

[0146] Optional, such as Figure 9 As shown, steps S2 and S3 include the following steps:

[0147] Data extraction: Obtain the effective area, airflow, and temperature values ​​of the heat dissipation components. After the simulation stabilizes, select and create an orthographic projection area, set the normal to [1,0,0], select the created local coordinate system (cac or rad), and select the inlet boundary interface of the heat dissipation component in sequence. The frontal projection areas A2 of the intercooler and A3 of the heat dissipation unit are then obtained, each 0.1529 m². 2 and 0.2738m 2 Select "Create Mass Flow Rate," choose "kg / s" as the unit, and then select the inlet boundary interface of the heat dissipation component in sequence to obtain the airflow value (m) of the intercooler. 2 The value is 1.1676 kg / s. The surface average value is selected, the scalar field function is set to "Temperature", the unit is set to "℃", and the component is selected as the inlet boundary interface of the radiator. The actual temperature value T in front of the radiator is then obtained. r The temperature was 47.34℃.

[0148] Numerical calculation: Calculation of the temperature difference between the condenser and intercooler. Based on the test bench data of the engine installed in the vehicle, the heat dissipation Q2 of the intercooler under the target operating condition is obtained as 22kW. The calculation is based on the intercooler's air intake volume m2, the intercooler's heat dissipation Q2, and the intercooler temperature difference (intercooler temperature rise) ΔT2, where the expression for the intercooler temperature difference ΔT2 is:

[0149]

[0150] Among them, specific heat capacity c p，c The value is 1.04 J / (kg·℃), and the intercooler temperature difference ΔT2 is 10.12℃. It should be noted that in this embodiment, the condenser is located on the right side of the vehicle's driving direction; therefore, the condenser temperature difference is not considered when calculating the temperature difference of the heat dissipation components.

[0151] Numerical calculation: Calculation of the theoretical temperature in front of the radiator (the theoretical temperature at the front end of the radiator). Based on the ambient temperature T. e Intercooler temperature difference ΔT2, Radiator theoretical inlet temperature T d The frontal projected area of ​​the intercooler is A2, and the frontal projected area of ​​the radiator is A3. Using the equivalent area method, the temperature difference ΔT2 of the intercooler with area A2 is equivalent to that of the radiator with area A3, where the theoretical inlet temperature T of the radiator is... d The expression is:

[0152]

[0153] In this embodiment, the ambient temperature T e The theoretical inlet temperature T of the radiator is 30℃. d The temperature was 40.12℃.

[0154] Numerical calculation: Hot air return temperature calculation. Based on the theoretical inlet temperature T of the radiator. d The actual temperature value T in front of the radiator r Calculate the hot air return temperature value (hot air return temperature) t, where the expression for the hot air return temperature value t is:

[0155] t = T r -T d .

[0156] Numerical calculation: Correction calculation for permissible ambient temperature of the whole vehicle. Based on the permissible ambient temperature T obtained from the three-dimensional / one-dimensional coupled calculation. z Given the hot air recirculation assessment temperature t, calculate the corrected allowable ambient temperature (the corrected value for the vehicle's allowable ambient temperature) T. The expression for the corrected allowable ambient temperature T is:

[0157] T = T z-t where T is the allowable ambient temperature obtained from the three-dimensional / one-dimensional coupled calculation. z The value was 53.75℃, the corrected allowable ambient temperature T was 46.53℃, and the test allowable ambient temperature was 44.94℃. The difference between the corrected allowable ambient temperature and the test value was controlled within ±2℃, meaning that the two were more consistent.

[0158] In this embodiment, CFD thermal balance simulation calculations are performed using STAR-CCM+ software. A local coordinate system and interface surface are set up to obtain the streamlined state of the commercial vehicle engine compartment and the temperature cloud map of the heat dissipation components. Then, CFD post-processing is used to extract data, obtaining the effective area value, airflow value, and temperature value of the heat dissipation components. Finally, based on the extracted data, hot air recirculation evaluation calculations are performed to obtain the hot air recirculation temperature value and the vehicle's allowable ambient temperature correction value. This allows for a quantitative description of the impact of hot air recirculation based on CFD simulation software. It can not only guide the arrangement of anti-backflow baffles in conjunction with the streamlined state in the engine compartment, reducing the impact of hot air recirculation on the inlet air temperature at the front end of the heat dissipation components, but also compare the specific impact of adding anti-backflow baffles on the recirculation temperature, verifying the rationality and effectiveness of the recirculation baffle arrangement. Furthermore, it can correct the vehicle's allowable ambient temperature, making the vehicle's allowable ambient temperature more consistent with the experimental value, improving simulation accuracy, reducing the number of experiments, and achieving the goal of cost reduction and efficiency improvement. In the field of commercial vehicle R&D, it has certain engineering practical value.

[0159] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0160] Based on the same inventive concept, this application also provides an engine compartment hot air recirculation assessment device for implementing the above-mentioned engine compartment hot air recirculation assessment method. The solution provided by this device is similar to the solution described in the above method. Therefore, the specific limitations of one or more engine compartment hot air recirculation assessment device embodiments provided below can be found in the limitations of the engine compartment hot air recirculation assessment method above, and will not be repeated here.

[0161] In one embodiment, such as Figure 10 As shown, a hot air recirculation assessment device 1000 for an engine compartment is provided, comprising: an acquisition module 1001 and a determination module 1002, wherein:

[0162] The acquisition module 1001 is used to acquire simulation data and test data of the vehicle engine compartment under the target working conditions. The simulation data includes the front projection area of ​​the intercooler, the front projection area of ​​the radiator, the air intake of the intercooler, and the actual temperature of the front end of the radiator. The test data includes the heat dissipation of the intercooler.

[0163] The determination module 1002 is used to determine the temperature rise of the intercooler based on the heat dissipation and air intake of the intercooler.

[0164] The determination module 1002 is also used to determine the equivalent temperature rise corresponding to the temperature rise of the intercooler based on the front projected area of ​​the intercooler, the front projected area of ​​the radiator, and the temperature rise of the intercooler.

[0165] The determination module 1002 is also used to determine the theoretical temperature of the front end of the radiator based on the equivalent temperature rise of the intercooler and the ambient temperature.

[0166] The determination module 1002 is also used to obtain the hot air return temperature based on the difference between the actual temperature and the theoretical temperature at the front end of the radiator. The hot air return temperature is used to characterize the degree of influence of hot air return on the inlet air temperature at the front end of the radiator.

[0167] In one embodiment, the simulation data also includes the air intake volume of the radiator, and the test data also includes the allowable ambient temperature. The hot air recirculation evaluation device 1000 in the engine compartment also includes a correction module, which is used to determine the allowable ambient temperature of the vehicle based on the air intake volume of the radiator; obtain a correction value for the allowable ambient temperature of the vehicle based on the difference between the allowable ambient temperature of the vehicle and the hot air recirculation temperature; and determine the degree of agreement between the correction value and the allowable ambient temperature based on the magnitude of the correction value and the allowable ambient temperature.

[0168] In one embodiment, a condenser is arranged in the vehicle engine compartment, and the condenser is positioned in front of the intercooler. The simulation data also includes the frontal projected area of ​​the condenser and the air intake of the condenser; the test data also includes the heat dissipation of the condenser; the determining module 1002 is further used to determine the temperature rise of the condenser based on the heat dissipation of the condenser and the air intake of the condenser; to determine the equivalent temperature rise corresponding to the temperature rise of the condenser based on the frontal projected area of ​​the condenser, the frontal projected area of ​​the radiator, and the temperature rise of the condenser; and to determine the theoretical temperature of the front end of the radiator based on the equivalent temperature rise of the condenser, the equivalent temperature rise of the intercooler, and the ambient temperature.

[0169] In one embodiment, the acquisition module 1001 is further configured to build a three-dimensional vehicle model, perform volume meshing on the computational domain of the three-dimensional vehicle model to obtain a meshed vehicle computational domain; the three-dimensional vehicle model includes a heat dissipation component, a fan, and an engine, the heat dissipation component includes a condenser, an intercooler, and a radiator, wherein the intercooler is arranged in front of the radiator, the radiator is arranged in front of the fan, and the fan is arranged in front of the engine; local coordinate systems corresponding to the porous medium region of the condenser, the porous medium region of the intercooler, the porous medium region of the radiator, and the rotational domain of the fan are established respectively; based on the meshed vehicle computational domain, boundary surfaces corresponding to the porous medium region of the condenser, the porous medium region of the intercooler, the porous medium region of the radiator, and the rotational domain of the fan are established respectively; based on each local coordinate system and each boundary surface, the vehicle computational model is determined; based on the vehicle computational model, thermal balance simulation calculation is performed to obtain multiple simulation data.

[0170] In one embodiment, the hot air recirculation evaluation device 1000 for the engine compartment further includes an evaluation module. The evaluation module is used to obtain a streamline development state diagram and a temperature cloud map of the heat dissipation components within the engine compartment based on multiple simulation data. The streamline development state diagram within the engine compartment includes hot air streamlines, which characterize the recirculated hot air that flows back from the rear of the heat dissipation components to the front of the heat dissipation components after being heated by the heat dissipation components. The temperature cloud map of the heat dissipation components includes the temperature cloud map of the intercooler and the temperature cloud map of the radiator. Based on the streamline development state diagram and the temperature cloud map of the heat dissipation components within the engine compartment, the degree of influence of the recirculated hot air on the heat dissipation performance of the heat dissipation components is evaluated.

[0171] In one embodiment, the evaluation module is further configured to: determine the airflow rate of the recirculated hot air around the heat dissipation component based on the density of the hot air streamlines; determine the first temperature value of the recirculated hot air around the heat dissipation component based on the spectral color of the hot air streamlines; determine the second temperature value of the recirculated hot air returning to the front of the intercooler and the front of the heat dissipation component based on the spectral color of each region in the temperature cloud map of the intercooler and the temperature cloud map of the heat dissipation component, respectively; and evaluate the degree of influence of the recirculated hot air on the heat dissipation performance of the heat dissipation component based on at least one of the airflow rate, the first temperature value, or the second temperature value.

[0172] Each module in the aforementioned engine compartment hot air recirculation assessment device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the computer device's memory as software, so that the processor can call and execute the corresponding operations of each module.

[0173] In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 11As shown, the computer device includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The input / output interface is used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, NFC (Near Field Communication), or other technologies. When executed by the processor, the computer program implements a method for evaluating the hot air recirculation in an engine compartment. The display unit is used to form a visually visible image and can be a display screen, projection device, or virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the computer device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the computer device, or external keyboards, touchpads, or mice, etc.

[0174] Those skilled in the art will understand that Figure 11 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0175] In one embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.

[0176] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps in the above method embodiments.

[0177] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0178] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0179] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0180] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for evaluating hot air recirculation in an engine compartment, characterized in that, The method includes: Acquire simulation and test data of the vehicle engine compartment under target operating conditions; the simulation data includes the frontal projected area of ​​the intercooler, the frontal projected area of ​​the radiator, the air intake of the intercooler, and the actual temperature of the front end of the radiator; the test data includes the heat dissipation of the intercooler. The temperature rise of the intercooler is determined based on its heat dissipation and air intake. Based on the frontal projected area of ​​the intercooler, the frontal projected area of ​​the radiator, and the temperature rise of the intercooler, the equivalent temperature rise corresponding to the temperature rise of the intercooler is determined; the equivalent temperature rise corresponding to the temperature rise of the intercooler is equivalent to the temperature rise of the radiator after the intercooler absorbs the heat dissipation of the intercooler, and is used to characterize the temperature rise of the radiator after absorbing the heat dissipation of the intercooler. The theoretical temperature of the front end of the radiator is determined based on the equivalent temperature rise of the intercooler and the ambient temperature. The hot air recirculation temperature is obtained based on the difference between the actual temperature and the theoretical temperature at the front end of the radiator. The hot air recirculation temperature is used to characterize the degree of influence of hot air recirculation on the inlet air temperature at the front end of the radiator.

2. The method according to claim 1, characterized in that, The simulation data also includes the air intake volume of the radiator; the test data also includes the allowable ambient temperature for testing; the method further includes: The permissible ambient temperature of the vehicle is determined based on the air intake of the radiator. Based on the difference between the allowable ambient temperature of the vehicle and the hot air recirculation temperature, a correction value for the allowable ambient temperature of the vehicle is obtained. The degree of agreement between the correction value and the allowable ambient temperature is determined based on the magnitude of the correction value and the allowable ambient temperature.

3. The method according to claim 1, characterized in that, A condenser is arranged in the engine compartment of the vehicle, and the condenser is located in front of the intercooler. The simulation data also includes the frontal projected area of ​​the condenser and the air intake of the condenser; the test data also includes the heat dissipation of the condenser. Determining the theoretical temperature of the radiator front end based on the equivalent temperature rise of the intercooler and the ambient temperature includes: The temperature rise of the condenser is determined based on the heat dissipation of the condenser and the air intake of the condenser. Based on the frontal projected area of ​​the condenser, the frontal projected area of ​​the radiator, and the temperature rise of the condenser, the equivalent temperature rise corresponding to the temperature rise of the condenser is determined; the equivalent temperature rise corresponding to the temperature rise of the condenser is equivalent to the temperature rise of the condenser after absorbing the heat dissipation of the air conditioner, and is used to characterize the temperature rise of the radiator after absorbing the heat dissipation of the air conditioner. The theoretical temperature of the radiator front end is determined based on the equivalent temperature rise of the condenser, the equivalent temperature rise of the intercooler, and the ambient temperature.

4. The method according to any one of claims 1 to 3, characterized in that, The acquisition of simulation data of the vehicle engine compartment under the target operating condition includes: A three-dimensional vehicle model is constructed, and the computational domain of the three-dimensional vehicle model is divided into volume meshes to obtain a meshed vehicle computational domain. The three-dimensional vehicle model includes a heat dissipation component, a fan, and an engine. The heat dissipation component includes a condenser, an intercooler, and a radiator. The intercooler is arranged in front of the radiator, the radiator is arranged in front of the fan, and the fan is arranged in front of the engine. Establish local coordinate systems corresponding to the porous media region of the condenser, the porous media region of the intercooler, the porous media region of the radiator, and the rotation domain of the fan, respectively; Based on the gridded vehicle computing domain, boundary surfaces corresponding to the porous media region of the condenser, the porous media region of the intercooler, the porous media region of the radiator, and the rotation domain of the fan are established respectively. Based on the local coordinate systems and the boundary surfaces, the vehicle calculation model is determined; Based on the vehicle calculation model, thermal balance simulation calculations were performed to obtain multiple simulation data.

5. The method according to claim 4, characterized in that, The method further includes: Based on the multiple simulation data, a streamline development state diagram and a temperature cloud map of the heat dissipation components are obtained in the engine compartment. The streamline development state diagram in the engine compartment includes hot air streamlines, which are used to represent the hot air returning from the rear of the heat dissipation components to the front of the heat dissipation components after being heated by the heat dissipation components. The temperature cloud map of the heat dissipation components includes the temperature cloud map of the intercooler and the temperature cloud map of the radiator. Based on the streamline development diagram within the engine compartment and the temperature cloud diagram of the heat dissipation component, assess the extent to which the recirculating hot air affects the heat dissipation performance of the heat dissipation component.

6. The method according to claim 5, characterized in that, The assessment of the impact of the recirculating hot air on the heat dissipation performance of the heat dissipation components, based on the streamline development diagram within the engine compartment and the temperature cloud diagram of the heat dissipation components, includes: The airflow volume of the recirculating hot air around the heat dissipation component is determined based on the density of the hot air flow lines. The first temperature value of the recirculating hot air around the heat dissipation component is determined based on the spectral color of the hot air streamline. Based on the temperature cloud map of the intercooler and the spectral color of each region in the temperature cloud map of the radiator, the second temperature value of the recirculated hot air flowing back to the front of the intercooler and the front of the radiator is determined respectively. The impact of the recirculated hot air on the heat dissipation performance of the heat dissipation component is evaluated based on at least one of the air volume value, the first temperature value, or the second temperature value.

7. A hot air recirculation assessment device for an engine compartment, characterized in that, The device includes: The acquisition module is used to acquire simulation data and test data of the vehicle engine compartment under the target working condition; the simulation data includes the front projection area of ​​the intercooler, the front projection area of ​​the radiator, the air intake of the intercooler and the actual temperature of the front end of the radiator, and the test data includes the heat dissipation of the intercooler; The determination module is used to determine the temperature rise of the intercooler based on the heat dissipation and air intake of the intercooler; The determining module is further configured to determine the equivalent temperature rise corresponding to the temperature rise of the intercooler based on the front projected area of ​​the intercooler, the front projected area of ​​the radiator, and the temperature rise of the intercooler; the equivalent temperature rise corresponding to the temperature rise of the intercooler is to apply the temperature rise of the intercooler after absorbing the heat dissipation of the intercooler to the radiator, and is used to characterize the temperature rise of the radiator after absorbing the heat dissipation of the intercooler. The determining module is further configured to determine the theoretical temperature of the front end of the radiator based on the equivalent temperature rise of the intercooler and the ambient temperature. The determining module is further configured to obtain the hot air recirculation temperature based on the difference between the actual temperature and the theoretical temperature at the front end of the radiator. The hot air recirculation temperature is used to characterize the degree of influence of hot air recirculation on the inlet air temperature at the front end of the radiator.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

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