Modification Design And Multi-objective Optimization Of Atkinson Circulation Engine

With the consumption of petroleum resources and the aggravation of environmental pollution caused by automobiles,developing green,low pollution or zero pollution electric products is imminent,Moreover,the government and many automakers have been working on the development of all kinds of electric vehicles.At present,the main types of electric vehicles in the market are battery electric vehicles(BEV),hybrid electric vehicles(HEV)and fuel cell electric vehicles(FCEV).Based on the limitation of the traditional Auto cycle,the market tends to adopt Atkinson cycle gasoline engine to meet the demand of HEV.The Atkinson cycle has obvious advantages over the Otto cycle in terms of economic efficiency.In this paper,a combination of theoretical analysis,numerical simulation and experimental verification is adopted,this article aims at the problem that the original thermal efficiency of the original Auto cycle gasoline engine is not suitable for HEV.Based on minor changes,the related parts are changed into Atkinson cycle,and the modified engine is calibrated and verified on the bench.In order to solve the problem of long time consuming and single optimization of the target in calibration,the response surface method is used to optimize the performance of the modified engine based on the coupling model of MODEFRONTIER and GT-Power,and the optimization scheme is verified on the Atkinson cycle gasoline engine test bench with the optimization parameters for guided.The main work and innovations of the paper were as follows:(1)Firstly,analyze the advantages of the Atkinson cycle over the Alto cycle theoretically.Secondly,use a professional one-dimensional engine simulation software GT-POWER to establish a simulation calculation model of the original Otto cycle.Through experimental data validation,it was found that the error between the two meets the requirements of the application,the accuracy of the simulation model is verified,and the next-step retrofit design can be performed.(2)Proposed the technical means to realize the Atkinson cycle,calculated the geometric parameters of the Atkinson cycle engine,and brought the modified parameters into the calculation model of the original machine to complete the modification of the gasoline engine.The calibration of the modified engine wascompleted through a bench test,and the performance of the engine before and after the modification was compared and analyzed.(3)In order to solve the problem of lengthy calibration time and multi-objective optimization,the optimization of response surface is carried out in order to improve the effective power of the modified engine and reduce the fuel consumption rate by taking intake and exhaust timing,ignition advance angle,air fuel ratio and throttle opening as optimization variables.(4)Based on the optimization parameters of multi-objective optimization on response surface,a modified Atkinson cycle engine is tested.The experimental results and the data parameters of the coupled optimization are compared and analyzed.The results show that the proposed modification technique combined with the optimized method can effectively accomplish the expected goal.