Optimization Of Turbocharged Direct Injection Engine And Simulation Of Vehicle Based On China Stage-? Standard

With the increasing number of light-duty vehicles in China,the problem of fuel shortage and emissions pollutant has become more serious.These problems and the national?emission regulations have prompted researchers to develop new engine and vehicle technologies for optimizing the fuel economy and emissions.How to comprehensively optimize the engine's power,economy and emission to improve the vehicle performance under cycle conditions is the main research content of this paper.Taking a light-duty vehicle equipped with a 1.6T turbocharged direct injection engine as the research object,the GT-POWER model of the turbocharged direct injection gasoline engine was established,and the model accuracy is verified.The average simulation error is kept below 5%.Based on original geometrical dimensions,the engine power,economy,emission performance during the change of the electronic control parameters is studied,and the design variables in engine optimization are determined.Based on the GT-POWER simulation results,the multi-objective optimization design of the engine is carried out with the aim of engine torque,fuel consumption and NOx emissions.The different multi-objective optimization algorithms are compared,and the genetic algorithm is selected.The genetic algorithm optimization method is used to optimize the engine under different working conditions,the optimal electronic control parameter MAP is obtained.The multi-objective optimization results show that multi-objective optimization of engine intake/exhaust phase and ignition timing can balance the various opposite performances of the engine.The fuel consumption rate and NO_x emissions of the engine are significantly reduced,and engine torque remain basically unchanged.The optimization under different working conditions is different,but the integrated performance can achieve optimization goals.A vehicle performance simulation method based on engine performance is proposed.The simulation results of the GT-DIRVE vehicle model are compared with the original vehicle parameters,and the simulation accuracy basically meets the design requirements.The different test cycles of the national emission standards are analyzed and the impacts of engine optimization on vehicle performance are studied.The result show that the complex working conditions proportion of WLTC cycle result in a significant increase in the fuel consumption and NO_x emissions.The integrated fuel consumption and NO_x emissions of the optimized engine under WLTC driving conditions are reduced by 4.99%and 8.39%.It proves that the multi-objective optimization method of the engine has a certain improvement on the performance of the vehicle.The using of computer simulation technology is meaningful for the early development of engines and vehicle products.Based on the numerical simulation model,the multi-objective optimization design scheme is studied,and the optimization and improvement effect is obvious.It can effectively alleviate the problem of high cost and long time in the traditional optimization design,and it has reference value to determine the actual optimization plan of the engine and the vehicle.