An Off-road Vehicle Engine Heat Balance Analysis And Test Research On State

In certain off-road vehicles, in the development process of thedevelopment of the cooling system first according to the requirement of thevehicle environment using cooling system performance requirements,determine the engine heat and coolant flow rate of the cooling system, andthen determine the radiator cooling type, cooling area and fan cooling systemcomponents such as type, size, then the engine cooling system heat balancetest. In the engine cooling system in the process of thermal balance test,early due to factors such as testing equipment, environmental temperature,not according to the national standard GB/T12542-2009《automobile heatbalance road test method》 for vehicle road thermal balance test, in orderto quickly validate cooling system development can satisfy the requirementof environmental adaptability, so the first thing on the drum testenvironment storehouse simulation vehicle thermal balance test, testresults show that the cooling system development can meet environmentalrequirements. Although in the simulation environment storehouse drum testerheat balance of the vehicle road test can not fully reflect the real heatcapacity of the cooling system, but the difference between test results anddevelopment goals is larger, so initially determined the model developmentdo not meet the development goals of the cooling system, vehicle thermalbalance ability is insufficient.First of all, this paper analyzes the factors which influence the vehiclethermal balance capacity, according to the analysis results of computationalfluid dynamics analysis for vehicle, validation of cabin air flow, and thendetermine the improvement direction. Vehicle to the improved cooling systemheat balance test, the results still can’t meet the requirements of environmental adaptability.Theoretical analysis on the engine heat balance state, considering thesuv in the process of developing comprehensive cross-country mobilityfactors, choose the high power engine, power more than conventional vehiclesincreased significantly, and adjust the engine torque output characteristic,the maximum torque corresponding to the speed of1400r/min single pointimprovement for1200-1600r/min range for maximum torque output. In orderto improve the suv is high power, high torque limit condition (steep),obstacle, the more trenches through capacity. Limit condition is the producta shorter period of time through the special working condition, rather thanthe long time continuous operation condition. And according to GB/T12542-2009《auto thermal equilibrium road test method》 in the vehiclethermal equilibrium ability test condition is the inspection runcontinuously for a long time. In order to be able to accurately determinethe suv in encountered in the actual use of continuous driving conditions,to design reasonable vehicle thermal equilibrium ability, both fully meetthe use of vehicles may encounter extreme conditions, and avoid to meetworking conditions may not happen performance caused by excessive redundancy,therefore has carried on the theoretical analysis and actual traffic vehicleuse state measurement.In the theoretical calculation analysis, the suv in paving road and underthe working condition of the pavement road, can’t exist GB/T12542-2009《the auto thermal equilibrium road test method》 specified in the car with2, throttle fully open state running condition. In actual traffic vehicleuse state measurement, also did not appear thermal balance test rules enginemaximum torque working condition, so the suv vehicle thermal balance testof engine torque condition has carried on the revision, the revised thermalbalance test standard and reasonable, scientific and accurate reflect theperformance of the off-road vehicle cooling system.