Simulation Analysis For Exhaust Valve Control System Of Engine

As one of the main moving parts of diesel engines, the working status of the valve-train system directly affects the Exhaust valve control system which is a vital part of low speed diesel engine. It directly effects on the dynamic performance, economical efficiency,reliability and emission characteristic of diesel engine, which is the prerequisite of diesel engine’s working performance. So it is very important to the whole engine’s excellent performance and working stability. With the increasingly higher requirement to the performance and emission of low speed engine, and in order to adapt to the development of diesel engine intelligence, the research on exhaust valve control system with higher free degree and higher reliability is great significance to ensure good working performance and service life of diesel engine.Software-in-the-loop is used to independent development of X type electronic control system, SimulationX, Simulink and Silver are selected as platforms. The key parameters studied are the exhaust valve open/close angle,exhaust valve position and time delay,exhaust valve position fails. And control strategy for these are studied out. SimulationX is used for exhaust valve control system modeling, and the model of exhaust control system is set up that include typical hydraulic & pneumatic element, control unit, line and sensor. Through comparison of design scheme simulation result, the optimized design scheme is determined,and the control strategy effectiveness of control system is confirmed. Through simulation research of setting 3mm buffering distance and 0.5mm diameter of damping hole,while exhaust valve response time is contracted to 100ms, the design requirement is reached. The change of damping hole diameter in oil inlet from 3mm to 0.5mm in the exhaust valve control system improved the closing effect of the exhaust valve. The control policy is realized by Simulink and simulation research is carried out. Using Silver aggregate the models set by Simulationx and by Simulink, the strategy of open/close angle control and exhaust valve position judging is verified workable.