Optimization Of Cooling System Heat Transfer Performance Based On Commercial Vehicle Under-hood Heat Management Technology

Commercial vehicle under-hood is a semi-closed space with very strict temperature control requirements,on the one hand,the wire harness,plastic tube,rubber tube and other non-metallic parts in the under-hood easily become failure in high temperature,which influences the safety performance of vehicle;on the other hand,the engine needs reasonable cooling to ensure its best power and economy.In the limited space of under-hood,a large number of different shapes and complex components are arranged,which brings great pressure and severe challenges to the heat radiation of under-hood.Therefore,it is a complex and important task to optimize the cooling system and under-hood thermal management.This paper is based on the background of a company’s commercial vehicle that founded higher temperature of radiator water-out and poor performance of cooling system during road test.Combined the existing resources,firstly calculates the heat radiation performance of the main parts of cooling system(radiator,intercooler and fan).Then simplifies the model of under-hood and simulates its temperature field and velocity field by the method of CFD and then according to the simulation results,optimizes the design of cooling system.Finally through real car validation,the temperature of optimized cooling system reduces 5℃,solving the problem of heat radiation.The main contents of this paper are as follows:1.Calculates the cooling system performance theoretically.According to the performance parameters of cooling system parts,theoretically calculates their thermal performance.Combined the performance parameters of engine,makes sure that every parts of the cooling system can meet the matching requirements of engine.2.Analyzes the factors affect cooling performance.Uses a 3D modeling software to build 3D model of the engine and a CFD software to mesh the model and simulate the temperature field and velocity field.According to the simulation results of temperature field and velocity field distribution,finds the parts or components that affect the air flow and thermal performance.3.Optimizes the thermal performance of cooling system.Studies influence of radiator,fan and fan shroud’s position and structure on thermal performance.According to the analysis,optimizes the layout of radiator,fan and fan shroud to make sure the best thermal performance.4.Tests validation.According to the optimization results,improves the design of vehicle and then tests,proving the validity of analysis and optimal design of cooling system with thermal management technology which can be used as guide-line for development of the cooling system of new products.