Research On Multi-parameters Optimization Method And Coupling Law Of Fully Variable Valve Engine

The technology of fully variable valve could increase the volumetric efficiency, torque, power meanwhile decreasing and controlling the emission of nitrogen oxide, which has a great significance in the requirement of energy-saving and emission-reduction. In different working conditions,traditional optimization of variable valve parameters are mainly gotten from calibration of test under rated condition. For the multi-parameters characteristic of fully variable valve technology, we need more accuracy variable valve parameters and finer optimization method. In addition, among the fully variable valve parameters, for the difference of constituent elements of the same valve motion angle area, there is some certain coupling relationship. This relationship has a great influence on optimizing and regulating the valve motion parameters. Therefore, this paper, for the fully variable valve technology, based on the construction of CY4102 diesel engine electro- hydraulic test bench and the multi-objective optimization method, makes optimization design of valve motion parameters of the actual engine model, and with applying statistical correlation analysis method,similarly analysis the multi-parameter coupling rules of full variable valve multi-parameters of the diesel engine. The detail job is below.Firstly, based GT-POWER, this paper builds a engine model with one dimensional working process, on the basis of this, completes the improvement of the fully variable valve model, and completes the verification and calibration of the simulation model, which provides the conditions for parameter optimization and performance verification..Secondly,in the simulation environment of modeFRONTIER,combined with calibrated GT-POWER simulation model, this paper establishes optimization simulation workflow, uses multi-objective optimization function of modeFRONTIER and uses genetic algorithm to find optimization result for full variable valve model, in the area of full working condition, obtaining optimization results of valve motion parameters of CY4102 diesel engine. Meanwhile this paper does some correlation analysis based on the simulation data generated in the process of optimization,and combine with the influence factor of the performance of the engine to investigate the coupling characteristics between the valve motion parameters and take verification on some operating points.Finally, based on influence factor analysis between the FVVA parameters and engine performances and the actual engine conditions demanded under different application background proposes control rules, namely the variable parameter MAP, this paper provides reference for the subsequent carrying out full variable valve system tracking control problem.