Characteristic Research Of Performance Parameters Of Intercooler For Heavy-duty Vehicles Based On China Ⅵ Emission Standard

As"carbon peaking"and"carbon neutrality"have become one of China’s key tasks in 2021,which has put forward higher requirements for vehicle exhaust emissions and accelerated the implementation of the China Ⅵ emission standards for heavy-duty vehicles.Turbocharged and intercooled technology is the main technical means to make the exhaust emissions of heavy-duty vehicles meet the China Ⅵ emission standards.Structural optimization and performance analysis of key components of this technology have become a research hotspot.As one of the indispensable components of turbocharged and intercooled technology,the intercooler is the main way to improve the performance of the technology.In this paper,three-dimensional simulation analysis,coupling optimization and experimental verification are used to analyze and optimize the overall performance of the intercooler of heavy-duty vehicles,and the optimization suggestions to the structure of the intercooler are provided in this paper.When the flow resistance and heat transfer characteristics of the air side of the intercooler of heavy-duty vehicles are studied,the influence of louver angleθ,louver pitch L_p,louver height L_h,fin pitch F_p and fin thicknessδ_f on the flow resistance and heat transfer performance of louver fin are explored based on the friction factor f,heat transfer factor j,and comprehensive performance evaluation factor E_jf for the performance evaluation index of louver fins.In addition,based on the L16（4⁵）orthogonal test,the structural parameters of louver fin for the heavy-duty vehicle intercooler are optimized.The influence of the louver fin structure parameters on the comprehensive performance evaluation factor E_jf is obtained by the range analysis method,and its significant degree is as follows:louver pitch L_p>fin pitch F_p>louver angleθ>louver height L_h>fin thicknessδ_f;The louver fin structure parameter with the best comprehensive performance evaluation factor E_jf are obtained.That is L_p=2.6mm,F_p=2.9mm,θ=24°,L_h=9.5mm andδ_f=0.13mm.After optimization,the heat transfer coefficient of the optimized louver fin increased by 16.33%,and the flow resistance decreased by 17.7%.In order to improve the air flow uniformity of the intercooler of heavy-duty vehicles,the heat transfer performance of the intercooler is further improved.In this paper,a proxy model of the intercooler guide vane structure parameters,including the diversion angleα,the number of rectangular holes in the guide vane and the width of the guide rectangular holes L,with respect to the airflow uniformity coefficient C and the pressure dropΔP is established.And the genetic algorithm is used to optimize structure parameters of guide vane and the guide vane parameters with the optimal airflow uniformity coefficient and the pressure drop are obtained,that is,diversion angleαis 18°,the width of the guide rectangular holes L is 6mm and the number of rectangular holes in the guide vane is 3.Besides,the optimized intercooler are verified based on three-dimensional numerical simulation,and it was found that the airflow uniformity coefficient of the optimized intercooler was 0.983,which was 5.25%higher than the original structure,the temperature uniformity of the intercooler has been significantly improved compared with the original structure,the outlet temperature of the intercooler is reduced by 8.2℃,and the heat exchange performance of the intercooler is significantly improved.In addition,the pressure loss of the intercooler with guide vanes after optimization is 9.63k Pa,which meets the design target value requirement of less than 12k Pa.The research on the characterization of the performance parameters for the intercooler in this paper provides a useful reference for the structural optimization design and performance improvement of the intercooler.