Research On The Retrofit Design And Heat Dissipation Performance Of The Heat Dissipation System Of The Engine Compartment Of A Special Vehicle

In order to improve the maneuverability and passing ability of a special vehicle,the chassis is improved on the basis of a certain type of off-road vehicle,which causes the front and rear suspension to be shortened,resulting in the mismatch between the engine cabin space and the original heat dissipation system.In this paper,the general layout and main components of engine cabin heat dissipation system are modified and redesigned,so that the heat dissipation performance of heat dissipation system can meet the design requirements.First of all,according to the layout of the heat dissipation system and related design parameters of the engine cabin of the prototype vehicle,the model is modeled,and the CFD simulation analysis is performed to obtain the flow field distribution characteristics and extract the key point data,which is used as the reference for subsequent modification.Secondly,due to the change of the engine room after the vehicle is modified,the heat dissipation system in the cabin is redesigned according to the design principle and the functional requirements of the heat dissipation system.The main measures are to provide the air inlet on the engine cover,change the parameters of the radiator and equip the radiator with double electric fans,so as to guarantee the functional requirements and design requirements of the heat dissipation system.The matching parameters of the components of the heat dissipation system are calculated by using the empirical formula,and the preliminary layout scheme is given and the component parameters are set.Then,the flow field of engine cabin of special vehicle is simulated and analyzed,and it is found that the heat dissipation of the radiator is difficult,and the cause of the difficulty in radiator heat dissipation is found out.By adjusting the fan speed to increase the air intake of the radiator and by constantly adjusting the installation angle of the radiator,the maximum air flow rate of the upwind area of the radiator can be obtained.The simulation analysis of the optimized heat dissipation system proves that the heat dissipation effect of the optimized engine cabin heat dissipation system is basically the same as that of the prototype vehicle.Finally,a bench test was conducted on the radiator to verify its heat dissipation capability.The thermal balance test of the whole vehicle was carried out,and the results of ATB characteristic evaluation and analysis showed that the test results met the design requirements,and the error is within the allowable range by comparing the test and simulation data,which confirms that the simulation data is basically reliable.