A thermal management test method and system based on a chassis dynamometer and an environmental chamber

Abstract

The application provides a thermal management test method and system based on a chassis dynamometer and an environmental chamber, belongs to the field of whole vehicle cooling performance test methods, and installs temperature sensors, pressure sensors and flowmeters required in the test; the test sample vehicle is fixed on the chassis dynamometer, the sensors are connected with the data acquisition system and are debugged, the environmental chamber is started after it is confirmed that data transmission and acquisition are correct; after the test sample vehicle and the chassis dynamometer are preheated, a coasting test is performed, road coasting resistance coefficients a, b and c are respectively input into the chassis dynamometer, the sample vehicle is in a neutral state, the sample vehicle is automatically dragged to 100km / h by the chassis dynamometer, then is freely coasted to a speed of 0km / h, is coasted for three times, after the coasting is finished, the consistency of the coasting data curve is checked and one group with a coasting time error within ±3% and the smallest error is selected from three groups; after the coasting is finished, steady state test conditions and transient test conditions are performed to test the whole vehicle thermal management performance.

Description

Technical Field

[0001] This invention belongs to the field of vehicle cooling performance testing methods, specifically relating to a thermal management testing method and system based on a chassis dynamometer and an environmental chamber. Background Technology

[0002] Thermal management is an important indicator for assessing a vehicle's tolerance to real-world environments and also provides data support for reducing fuel consumption. Generally, vehicle thermal management tests are conducted on actual roads. Due to the stringent testing conditions, the environmental limits required for vehicle road thermal management tests pose risks to driving safety and potential hazards during the test. Since the tests are conducted outdoors, environmental factors are uncontrollable, specifically temperature, humidity, and wind speed. Furthermore, due to the uncontrollable environmental factors, the consistency of the test environment under the same conditions is poor, and the repeatability of test data under the same environmental conditions is not high.

[0003] In the prior art, CN201410444352.6 discloses an indoor testing device and method for vehicle thermal balance capability. This document includes a chassis dynamometer, an environmental chamber equipped with a temperature control system, a cooling fan, and a temperature data acquisition system. The document describes the installation of sensors for engine inlet / outlet water, radiator inlet / outlet water, and ambient temperature on the entire vehicle. The temperature data acquisition system is then used for debugging to ensure the validity and stability of all sensor data. The vehicle with sensors is driven onto the chassis dynamometer and aligned. The chassis dynamometer's fixing device secures the vehicle to its non-drive wheels and body, ensuring the cooling fan outlet faces the vehicle's air intake grille. The distance between the cooling fan and the air intake grille is adjusted to 0.6-1 meter. The temperature control of the environmental chamber is adjusted to the temperature required for the thermal balance test. After the vehicle has been immersed for more than 4 hours, the engine is started to warm it up. This document describes a chassis dynamometer loaded with the vehicle's maximum gross weight, adjusted to a constant speed mode. It calculates the vehicle speed corresponding to the engine's maximum torque point by analyzing the vehicle's transmission and gear ratios, and adjusts accordingly. The engine throttle is fully open, and the engine coolant temperature from the temperature data acquisition system is observed and recorded for the last 15 minutes of stability, with a temperature change rate of 0.5℃ / 10 minutes. This document tests the matching and requirements of the vehicle's engine and cooling system based on the engine inlet and outlet coolant temperatures at maximum power and maximum torque points, as well as the radiator inlet and outlet coolant temperatures. Although the test is conducted in an indoor environment, this document cannot account for road rolling resistance and drag coefficients, nor can it consider the impact of various parameters such as oncoming wind speed on the prototype vehicle. This results in significant errors in the test data, failing to meet testing requirements and providing insufficient data support for vehicle development. Summary of the Invention

[0004] This invention provides a thermal management test method based on a chassis dynamometer and an environmental chamber. The method can solve the problems of poor driving safety, uncontrollable test environment and test conditions, and poor repeatability of test data in the whole vehicle road thermal management test.

[0005] The methods include:

[0006] S11, Install the temperature sensor, pressure sensor and flow meter required for the test;

[0007] S12, fix the test vehicle on the chassis dynamometer, connect the sensors and data acquisition system and debug them. After confirming that the data transmission and acquisition are correct, open the environmental chamber and set the temperature of the environmental chamber to 32℃ to 37℃.

[0008] S13, After the test vehicle and chassis dynamometer have warmed up, a coasting test is conducted, based on the resistance provided by road coasting, F = av. 2 +bv+c, input the road skid resistance coefficients a, b, and c into the chassis dynamometer, and the oncoming fan speed V is calculated according to V = n²v. 2 +n1v+n0 sets the vehicle speed v to follow. At this time, the prototype vehicle is in neutral. The chassis dynamometer automatically tows the prototype vehicle to 100km / h, and then it coasts freely to a speed of 0km / h. After coasting three times, the consistency of the coasting data curve is checked and the group with the smallest error in the coasting time within ±3% is selected from the three groups.

[0009] S14. After the coasting is completed, steady-state test conditions and transient test conditions are conducted to test the thermal management performance of the vehicle.

[0010] It should be further noted that, in the method, the test vehicle and chassis dynamometer are preheated after the ambient temperature is set to 32°C to 37°C and stabilized.

[0011] The preheating method involves driving the test vehicle on a chassis dynamometer at 80% of its maximum speed for at least 30 minutes until the rear axle temperature reaches 60% of the maximum allowable temperature of the rear axle gear oil.

[0012] If the rear axle temperature meets 60% of the maximum allowable temperature of the rear axle gear oil when two consecutive test conditions are performed, then warming up the engine is not required.

[0013] It should be further noted that each temperature measuring point in S11 is equipped with two temperature sensors, and the temperature sensors are K-type thermocouples. Each pressure measuring point is equipped with at least one pressure sensor.

[0014] It should be further noted that when conducting the constant speed fuel consumption test in S14, after the test vehicle reaches a fixed speed in a fixed gear, the accelerator pedal should be kept steady so that the vehicle speed does not fluctuate by more than ±0.1 km / h. Data should be recorded when the engine water temperature and coolant flow rate have stabilized for 1 minute and the temperature difference between the engine water temperature and coolant flow rate is ≤ ±0.5℃.

[0015] It should be further noted that the constant speed fuel consumption test involves recording a set of data for each test vehicle traveling the same fixed distance. At least three sets of valid data are recorded at each speed point. The fixed distance traveled must be the same when recording data at each speed point. The three sets of fuel consumption data per 100 kilometers must not exceed 1% to be valid. Engine system parameters, temperature and pressure data at each measuring point, flow meter flow, and fuel temperature are recorded in real time.

[0016] It should be further explained that the maximum gradeability test was conducted using a chassis dynamometer in S14. The chassis dynamometer increased the grade in increments of 0.2%, and the grade change was adjusted after the throttle was fully depressed so that the target speed remained constant.

[0017] Data recording begins after the engine outlet water temperature and coolant flow rate have stabilized for 1 minute and the temperature difference between the engine outlet water temperature and coolant flow rate is ≤ ±0.5℃. Real-time recording of engine system parameters, temperature and pressure at each measuring point, flow meter flow rate, fuel temperature, vehicle speed, and gradient is performed.

[0018] It should be further noted that in the S14 vehicle thermal management test, constant speed fuel consumption test and maximum gradeability test are selected for steady-state conditions, and CHTC and C-WTVC cycle conditions are selected for transient conditions.

[0019] It should be further noted that the transient operating conditions in S14 are CHTC and C-WTVC cycles. During the test, engine parameter data, water temperature, coolant flow rate, temperature and pressure parameters of each sensor measuring point, fuel consumption, oil temperature, transient test cycle test data are recorded in real time, and three sets of fuel consumption per 100 kilometers not exceeding 1% are recorded as valid data.

[0020] The present invention also provides a thermal management test system based on a chassis dynamometer and an environmental chamber, the system comprising: a temperature sensor, a pressure sensor, a flow meter, a preheater, a chassis dynamometer, and a test terminal;

[0021] The test terminal is equipped with a CAN acquisition module, a data storage module, a data analysis module, and a data display module;

[0022] The data acquisition module is connected to the temperature sensor, pressure sensor and flow meter respectively, and receives temperature information, pressure information and water flow information during the test process;

[0023] The CAN acquisition module is connected to the vehicle controller to acquire data information of the test vehicle during the test process;

[0024] The chassis dynamometer is used to fix the test vehicle. The chassis dynamometer is based on F=av 2 +bv+c provides the road skidding resistance, and the road skidding resistance coefficients a, b, and c, along with the oncoming fan speed V, are calculated according to V = n²v. 2 +n1v+n0 sets the vehicle speed v to follow. At this time, the prototype vehicle is in neutral. The chassis dynamometer automatically tows the prototype vehicle to 100km / h, and then it coasts freely to a speed of 0km / h. After coasting three times, the consistency of the coasting data curve is checked and the group with the smallest error in the coasting time within ±3% is selected from the three groups.

[0025] The preheater is used to heat the ambient chamber temperature to 32°C to 37°C;

[0026] The data storage module is used to store experimental process data and experimental results.

[0027] The data analysis module is used to analyze the data and information from the experimental process and draw the final experimental conclusions.

[0028] The data display module is used to display experimental process data and experimental results.

[0029] It should be further noted that the information collected by the data acquisition module includes: engine inlet and outlet water temperature, intercooler inlet and outlet air temperature, air intake temperature after air filter, ambient temperature, and rear axle temperature; the pressure measurement points include engine inlet and outlet air pressure, intercooler inlet and outlet air pressure, expansion tank pressure, air intake pressure after air filter, and exhaust back pressure.

[0030] As can be seen from the above technical solutions, the present invention has the following advantages:

[0031] Compared to road testing, the thermal management testing method based on a chassis dynamometer and an environmental chamber provided by this invention offers advantages such as high driving safety, complete controllability of the same test conditions, strong controllability of test environment conditions, accurate test data, and convenient data repeatability verification. The chassis dynamometer can accurately simulate the road driving resistance matched to the prototype vehicle, refer to the influence of various parameters such as oncoming wind speed on the prototype vehicle, and record various parameters of the vehicle during the test in real time, providing data support for vehicle development, improving development efficiency, ensuring the accuracy of test results data, and meeting test requirements.

[0032] This invention also summarizes test process data and results, facilitating access for test personnel and effectively improving test process monitoring efficiency. It also enables efficient collection, storage, and processing of test data, using a multi-dimensional space to describe the entire test process. This improves the quality and efficiency of vehicle testing, promptly identifies data anomalies during testing, enhances test process management and efficiency, controls risks in vehicle manufacturing, and ultimately achieves timely and scientific supervision, management, and control throughout the entire testing process. Attached Figure Description

[0033] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a flowchart of a thermal management test method based on a chassis dynamometer and an environmental chamber.

[0035] Figure 2 This is a schematic diagram of a thermal management test system based on a chassis dynamometer and an environmental chamber.

[0036] Figure 3 This is a schematic diagram of an embodiment of a thermal management test system based on a chassis dynamometer and an environmental chamber.

[0037] Explanation of the attached diagram labels: A - Environmental chamber, B - Chassis dynamometer, C - Test vehicle, D - Frontal fan. Detailed Implementation

[0038] The thermal management testing method based on a chassis dynamometer and an environmental chamber provided by this invention addresses the problems of existing technologies where outdoor road testing is easily affected by environmental factors, these factors are uncontrollable, the test environment lacks consistency under the same operating conditions, and the test data has low repeatability under the same environmental conditions. Therefore, this invention provides a thermal management testing method based on a chassis dynamometer and an environmental chamber, conducting tests within an indoor environmental chamber as a laboratory, utilizing technologies such as sensors, dedicated artificial intelligence chips, cloud computing, distributed storage, big data processing, operating / interactive systems, and mechatronics. This invention also incorporates computer program code, with programming languages ​​including but not limited to object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the test terminal as a standalone software package. The test terminal can also be a remote computer, connected to the test equipment via any type of network—including a local area network (LAN) or a wide area network (WAN)—for remote testing operations.

[0039] In this way, the present invention utilizes a chassis-based dynamometer and an environmental chamber to establish test conditions and operating conditions. By using sensor monitoring, data transmission and other technologies, it can accurately simulate the road driving resistance matched by the prototype vehicle and record various parameters of the vehicle during the test in real time, providing data support for the development of the whole vehicle and improving development efficiency.

[0040] The following will refer to the appendices in the embodiments of the present invention. Figures 1 to 2 The technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0041] Here, it is necessary to explain the C-state inspection of the test vehicle. The test vehicle inspection is based on the test vehicle inspection checklist: the test vehicle configuration is consistent with the test outline, break-in mileage, appearance, tires, engine oil level, antifreeze level, fuel tank level, urea level, presence of leaks, engine condition, air conditioning, cigarette lighter, mudguards, counterweights, battery, and driving inspection.

[0042] It should be further noted that the break-in mileage must meet the standard requirements. Tires: In good condition, normal wear, and tire pressure meeting technical requirements. A counterweight of 2-4 tons is applied above the drive axle of the prototype vehicle according to test requirements. Driving inspection: The vehicle must be driven in the park for at least 20 minutes; the engine, transmission, drive axle, steering system, and braking system must function normally.

[0043] The following is a possible embodiment, with its specific implementation described in a non-limiting manner. The steps of the vehicle thermal management test method are as follows:

[0044] Step S11: Install the temperature sensors, pressure sensors, and flow meters required for the test. The temperature measurement points include the engine inlet and outlet water temperatures, the intercooler inlet and outlet air temperatures, the intake air temperature after the air filter, the ambient temperature, and the rear axle temperature; the pressure measurement points include the engine inlet and outlet air pressures, the intercooler inlet and outlet air pressures, the expansion tank pressure, the intake air pressure after the air filter, and the exhaust back pressure.

[0045] In the embodiments of the present invention, to ensure the accuracy and reliability of the test data, two temperature sensors are installed at the same location at each temperature measuring point, and the temperature sensors are K-type thermocouples. At least one pressure sensor is installed at each pressure measuring point. Temperature and pressure measuring points can be added as needed, but the number of measuring points cannot be reduced.

[0046] Step S12: The test vehicle C is fixed on the chassis dynamometer B. The sensors and data acquisition system are connected and debugged. After confirming that the data transmission and acquisition are correct, the environmental chamber A is opened. The temperature of the environmental chamber A is set to 32℃ to 37℃, preferably 35℃. After the temperature of the environmental chamber A reaches 35℃ and stabilizes, the test vehicle C and the chassis dynamometer B are preheated. The preheating method is to drive the test vehicle C on the chassis dynamometer B at 80% of its maximum speed for at least 30 minutes, while the rear axle temperature reaches 60% of the maximum allowable temperature of the rear axle gear oil.

[0047] Step S13: After the test vehicle C and chassis dynamometer B have finished warming up, a coasting test is first conducted. Based on the resistance provided by road coasting, F = av2 + bv + c, the road coasting resistance coefficients a, b, and c are input into the chassis dynamometer B respectively. The wind speed V of the oncoming fan D is set according to V = n2v2 + n1v + n0, and the vehicle speed v follows. At this time, the test vehicle C is in neutral. The chassis dynamometer B automatically tows the test vehicle to 100 km / h, and then coasts freely to a speed of 0 km / h. The coasting is performed three times and the data is valid. After the coasting is completed, the consistency of the coasting data curve is checked and the group with the smallest error in the coasting time within ±3% is selected.

[0048] Step S14: After the coasting is completed, perform steady-state test conditions and transient test conditions to test the vehicle's thermal management performance.

[0049] The test method of the present invention involves warming up the engine before the test and selecting constant speed fuel consumption test and maximum gradeability test under steady-state conditions.

[0050] In this invention, during the constant-speed fuel consumption test, the test vehicle C is in a fixed gear, at a fixed speed, and on a fixed slope. When the test vehicle C reaches the required gear and speed, the test driver holds the accelerator pedal steady, ensuring the speed does not fluctuate by more than ±0.1 km / h. The engine coolant temperature, fan speed, coolant flow rate, parameters of each sensor point, fuel consumption, and oil temperature are monitored in real time. Data recording begins after the engine coolant temperature and coolant flow rate stabilize. For the constant-speed fuel consumption test, a set of data is recorded for each fixed distance traveled by the test vehicle C, with at least three sets of valid data recorded at each speed point. For the maximum gradeability test, a fuel consumption reduction of no more than 1% per 100 kilometers is considered valid. During the maximum gradeability test, a fixed gear and engine speed are used. The test vehicle C is first raised to the fixed gear and engine speed. The gradient is then input to the chassis dynamometer B in 0.2% increments. The test driver increases the throttle opening to maintain a constant engine speed until the throttle opening reaches 100%. The gradient is adjusted until both engine speed and vehicle speed stabilize, then adjustment is stopped. The various data parameters of the test vehicle C are monitored in real time until the engine coolant temperature and coolant flow rate stabilize. Data recording begins when the test vehicle C travels a fixed distance and one set of data is recorded. Only one set of data needs to be recorded. For the transient test conditions, the CHTC and C-WTVC cycles are selected. The test driver drives according to the cycle road pattern, recording engine data, coolant temperature, coolant flow rate, sensor parameters at various measuring points, fuel consumption, and oil temperature in real time. Three sets of valid data must be recorded for the transient test cycle. A fuel consumption reduction of no more than 1% per 100 kilometers is considered valid.

[0051] Sensor data is collected by the data acquisition module, vehicle parameters and engine parameters are collected by the CAN acquisition module, and all data are stored by the data storage module and analyzed by the data analysis module to draw conclusions.

[0052] The thermal management test method and system based on chassis dynamometer and environmental chamber provided by this invention can archive and store test process data and test result information.

[0053] The system includes an interface for configuring experimental process data and results, allowing operators to add unstored or unconfigured experimental data, or modify or delete existing data. Experimental results can be displayed as bar charts, line graphs, or data lists for operator reference.

[0054] This invention can summarize test process data and results, facilitating access for test personnel and effectively improving test process monitoring efficiency. It also enables efficient collection, storage, and processing of test data, using a multi-dimensional space to describe the entire test process. This improves the quality and efficiency of vehicle testing, promptly detects data anomalies during testing, enhances test process management and efficiency, controls risks in vehicle manufacturing, and ultimately achieves timely and scientific supervision, management, and control throughout the entire testing process.

[0055] The following are embodiments of the thermal management test system based on a chassis dynamometer and an environmental chamber provided in this disclosure. This system belongs to the same inventive concept as the thermal management test methods based on a chassis dynamometer and an environmental chamber in the above embodiments. For details not described in detail in the embodiments of the thermal management test system based on a chassis dynamometer and an environmental chamber, please refer to the embodiments of the thermal management test methods based on a chassis dynamometer and an environmental chamber described above.

[0056] like Figure 3 As shown, the system includes: a temperature sensor, a pressure sensor, a flow meter, a preheater, a chassis dynamometer, and a test terminal.

[0057] The test terminal is equipped with a data acquisition module, a CAN acquisition module, a control module, a data storage module, a data analysis module, and a data display module;

[0058] The data acquisition module is connected to the temperature sensor, pressure sensor and flow meter respectively, and receives temperature information, pressure information and water flow information during the test process;

[0059] The CAN acquisition module is connected to the vehicle controller to acquire data information of the test vehicle during the test process;

[0060] The chassis dynamometer is used to fix the test vehicle. The chassis dynamometer is based on F=av 2 +bv+c provides the road skidding resistance, and the road skidding resistance coefficients a, b, and c, along with the oncoming fan speed V, are calculated according to V = n²v. 2 +n1v+n0 sets the vehicle speed v to follow. At this time, the prototype vehicle is in neutral. The chassis dynamometer automatically tows the prototype vehicle to 100km / h, and then it coasts freely to a speed of 0km / h. After coasting three times, the consistency of the coasting data curve is checked and the group with the smallest error in the coasting time within ±3% is selected from the three groups.

[0061] The preheater is used to heat the ambient chamber temperature to 32°C to 37°C;

[0062] The data storage module is used to store experimental process data and experimental results.

[0063] The data analysis module is used to analyze the data and information from the experimental process and draw the final experimental conclusions.

[0064] The data display module is used to display experimental process data and experimental results.

[0065] The data acquisition module collects information including: engine inlet and outlet water temperature, intercooler inlet and outlet air temperature, air intake temperature after air filter, ambient temperature, and rear axle temperature; pressure measurement points include engine inlet and outlet air pressure, intercooler inlet and outlet air pressure, expansion tank pressure, air intake pressure after air filter, and exhaust back pressure.

[0066] Compared to road testing, the thermal management testing system based on a chassis dynamometer and an environmental chamber, as disclosed in this invention, offers advantages such as high driving safety, complete controllability of the same test conditions, strong controllability of test environment conditions, accurate test data, and convenient data repeatability verification. The chassis dynamometer can accurately simulate the road driving resistance matched to the prototype vehicle and can record various parameters of the vehicle during testing in real time, providing data support for vehicle development and improving development efficiency.

[0067] The units and algorithm steps of the various examples described in the disclosed embodiments of the thermal management test system of this invention can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of each example have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0068] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A thermal management test method based on a chassis dynamometer and an environmental chamber, characterized in that the method... include: S11, Install the temperature sensor, pressure sensor and flow meter required for the test; S12, fix the test vehicle on the chassis dynamometer, connect the sensor and data acquisition module and debug it. After confirming that the data transmission and acquisition are correct, open the environmental chamber and set the temperature of the environmental chamber to 32℃ to 37℃. S13, After the test vehicle and chassis dynamometer have warmed up, a coasting test will be conducted. The chassis dynamometer is based on F=av. 2 +bv+c provides the road skid resistance. The road skid resistance coefficients a, b, and c are input into the chassis dynamometer, and the oncoming fan speed V is calculated according to V=n²v. 2 +n1v+n0 sets the vehicle speed v to follow. At this time, the prototype vehicle is in neutral. The chassis dynamometer automatically tows the prototype vehicle to 100km / h, and then it coasts freely to a speed of 0km / h. After coasting three times, the consistency of the coasting data curve is checked and the group with the smallest error in the coasting time within ±3% is selected from the three groups. S14, after the coasting is completed, steady-state test conditions and transient test conditions are conducted to test the thermal management performance of the whole vehicle; The maximum gradeability test was conducted using a chassis dynamometer in S14. The chassis dynamometer increased the gradeability in increments of 0.2%, and the gradeability was adjusted after the throttle was fully depressed so that the target speed remained constant. Data recording begins when the engine outlet water temperature and coolant flow rate stabilize for 1 minute and the temperature difference between the engine outlet water temperature and coolant flow rate is ≤ ±0.5℃. Real-time recording of engine system parameters, temperature and pressure at each measuring point, flow meter flow rate, fuel temperature, vehicle speed, and gradient is performed. The counterweight is placed above the drive axle of the prototype vehicle with a load of 2-4 tons, according to the test requirements. In the method, after the ambient temperature is set to 32℃ to 37℃ and stabilized, the test vehicle and chassis dynamometer are preheated. The preheating method involves driving the test vehicle on a chassis dynamometer at 80% of its maximum speed for at least 30 minutes, until the rear axle temperature reaches 60% of the maximum allowable temperature of the rear axle gear oil. If the rear axle temperature meets 60% of the maximum allowable temperature of the rear axle gear oil when two consecutive test conditions are performed, then warming up the engine is not required.

2. The thermal management test method based on a chassis dynamometer and an environmental chamber according to claim 1, characterized in that, Each temperature measuring point in S11 is equipped with two temperature sensors, and the temperature sensors are K-type thermocouples. Each pressure measuring point is equipped with at least one pressure sensor.

3. The thermal management test method based on a chassis dynamometer and an environmental chamber according to claim 1, characterized in that, When conducting the constant speed fuel consumption test in S14, after the test vehicle reaches a fixed speed in a fixed gear, the accelerator pedal should be kept steady so that the vehicle speed does not fluctuate by more than ±0.1 km / h. Data should be recorded when the engine water temperature and coolant flow rate have stabilized for 1 minute and the temperature difference between the engine water temperature and coolant flow rate is ≤ ±0.5℃.

4. The thermal management test method based on a chassis dynamometer and an environmental chamber according to claim 3, characterized in that, The constant speed fuel consumption test involves recording a set of data for each test vehicle traveling the same fixed distance. At least three sets of valid data are recorded at each speed point. The fixed distance traveled must be the same when recording data at each speed point. The three sets of fuel consumption data per 100 kilometers must not exceed 1% to be valid. Engine system parameters, temperature and pressure data at each measuring point, flow rate and fuel temperature are recorded in real time.

5. The thermal management test method based on a chassis dynamometer and an environmental chamber according to claim 1, characterized in that, In S14, the vehicle thermal management test selects constant speed fuel consumption test and maximum gradeability test under steady-state test conditions, and selects CHTC and C-WTVC cycle conditions under transient test conditions.

6. The thermal management test method based on a chassis dynamometer and an environmental chamber according to claim 5, characterized in that, In S14, the transient test conditions are selected as CHTC and C-WTVC cycles. During the test, engine system parameters, water temperature, coolant flow rate, temperature and pressure parameters of each sensor measuring point, fuel consumption and oil temperature are recorded in real time. Three sets of valid data must be recorded for the transient test cycle conditions. Fuel consumption per 100 kilometers is considered valid if it does not exceed 1%.

7. A thermal management test system based on a chassis dynamometer and an environmental chamber, characterized in that, The system employs the thermal management test method based on a chassis dynamometer and an environmental chamber as described in any one of claims 1 to 6; The system includes: temperature sensors, pressure sensors, flow meters, preheaters, chassis dynamometers, and test terminal units; The test terminal is equipped with a data acquisition module, a CAN acquisition module, a control module, a data storage module, a data analysis module, and a data display module; The data acquisition module is connected to the temperature sensor, pressure sensor and flow meter respectively, and receives temperature information, pressure information and water flow information during the test process; The CAN acquisition module is connected to the vehicle controller to acquire data information of the test vehicle during the test process; The chassis dynamometer is used to fix the test vehicle. The chassis dynamometer is based on F=av 2 +bv+c provides the road skid resistance. The road skid resistance coefficients a, b, and c are input into the chassis dynamometer, and the oncoming fan speed V is calculated according to V=n²v. 2 +n1v+n0 sets the vehicle speed v to follow. At this time, the prototype vehicle is in neutral. The chassis dynamometer automatically tows the prototype vehicle to 100km / h, and then it coasts freely to a speed of 0km / h. After coasting three times, the consistency of the coasting data curve is checked and the group with the smallest error in the coasting time within ±3% is selected from the three groups. The preheater is used to heat the ambient chamber temperature to 32°C to 37°C; The data storage module is used to store experimental process data and experimental results. The data analysis module is used to analyze the data and information from the experimental process and draw the final experimental conclusions. The data display module is used to display experimental process data and experimental results. The maximum gradeability test was conducted using a chassis dynamometer. The chassis dynamometer gradually increased the grade by 0.2%, and the grade was adjusted after the throttle was fully depressed so that the target speed remained constant. Data recording begins when the engine outlet water temperature and coolant flow rate stabilize for 1 minute and the temperature difference between the engine outlet water temperature and coolant flow rate is ≤ ±0.5℃. Real-time recording of engine system parameters, temperature and pressure at each measuring point, flow meter flow rate, fuel temperature, vehicle speed, and gradient is performed. The counterweight is placed above the drive axle of the prototype vehicle with a load of 2-4 tons, according to the test requirements.

8. The thermal management test system based on a chassis dynamometer and an environmental chamber according to claim 7, characterized in that, The data acquisition module collects information including: engine inlet and outlet water temperature, intercooler inlet and outlet air temperature, air intake temperature after air filter, ambient temperature, and rear axle temperature; pressure measurement points include engine inlet and outlet air pressure, intercooler inlet and outlet air pressure, expansion tank pressure, air intake pressure after air filter, and exhaust back pressure.

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