Variable Valve Timing Control Of CCD

The component of intake air and the system pressure will change while the Closed Cycle Diesel (CCD) system works on open state and closed state. The original valve driving system may keep the performance only under the operation of diesel open state. The cam shape has been fixed before production and can not be adjusted to meet the closed cycle operation of the diesel engine. Meanwhile, the easy change of the engine valve switch phase, duration and lift is an important method to improve the engine performance, increase the thermal efficiency and reduce the emission discharge. So a hydraulically driving, electronically controlled variable valve system is developed based on the requirements for the closed cycle diesel and engine developments and its performance is studied.The mechanical, electronical and hydraulic simulation model is built for the electronically controlled hydraulic variable valve system. The studies on the main structure parameters of the system, such as piston diameter, spring rigidity of the valve and flow area of electro-magnetic valve, obtained the characteristics of the variable intake valve system, therefore may be used to guide the experiment bench design.Based on the simulation, a test is conducted on the cylinder heads of Dongan 465 engine with the variable valve system, which can provide experimental documents for the variable valve system development of closed cycle diesel. Test bench includes the variable valve actuator, hydraulic driving source, and PLC electronic control unit.Finally, the simulation model of the 4102BG Closed Cycle Diesel has been made with GT-POWER. So that the effect of variable valve timing on CCD performances will be predicted.