全可变气门机构动态调节特性对汽油HCCI运行的影响

利用GT-Power和Simulink搭建了进排气门升程相位全可变(4V)HCCI发动机仿真平台,其中包括单缸机模型、HCCI燃烧模型、4V型线生成器模型、4V机构执行器模型及发动机控制器模型．在此平台上分别研究了全可变气门的升程及相位的正向和反向动态调节特性对HCCI过渡运行的影响．仿真结果给出了HCCI过渡运行中相对于气门调节的时间滞后特性,为进一步的HCCI动态过程控制提供了基础数据．

Effects of Fully Variable Valve Actuator Dynamic Adjusting on HCCI Combustion Transition Operation

A fully variable valve actuating system called as 4VVAS is put forward to realize static, transient and mode switch operation for a gasoline HCCI engine based on internal ECR. According to experiment data, a dynamic response model of the 4VVAS was set up in Simulink code, along with a 4VVAS controller and a HCCI engine controller. By coupling simulations of the Simulink models and the GT-Power code, transient response of the HCCI engine to step change in the four control variables of 4VVAS were examined respectively. The effects on HCCI combustion transition of the four actuators ' response time constants were investigated and compared. It is found that engine load is more sensitive to exhaust valve actuators in most conditions, and too fast time constants of the four actuators will lead to HCCI combustion IMEP fluctuation or even misfire. The simulation results will form the foundation of transient control strategy for the HCCI engine based on the 4VVAS.