Development Of Total Cylinder Dumping System For A Diesel Engine

In the recent ten years, the advanced technology of emission control applying on thediesel engine,which resulted in the changes of physical and chemical characteristics of theparticles, led to sharp increases in number emissions of the tiny particles correspondingly.In order to study the particle generation and evolution, the author developed a total cylinderdumping system on the model 6102 diesel engine with the function of simulating EGR,intercooling and high pressure common rail (CR) and the main contents of the dissertationare as follows:(1) The system of CR was selected as fuel supply and injection system for the singlecylinder. The electronic control unit of the single cylinder CR system ECD-U2 wasdeveloped and designed using the hardware of the PC, programmable timer card, A/D cardand driving circuit and soft program with the result of good control of the CR that thesystem development needed. When the CR control system operated, not only the highpressure injection realized, but also the control for the injection pressure, quantity andtiming were flexible and reliable. The experimental results indicated that the control systemoperated with the high precision and dynamic performances, while the response of theinjection was quick and the output curve of the high pressure pump was smooth.(2) The inlet air system of the single cylinder included turbocharge, EGR and inlet airheating equipment. The dumping system contained dumping valve with sample dilutionsystem and valves deactuator. Referring to the former design, dumping valve and its drivingcomponents were improved. Dumping valve was deactuated by varying the position ofrocker arm shaft. Thus, the rocker arm shaft of single cylinder was redesigned solely andrealized the valves deactuating with its normal function.(3) PC, cards and MOSFET were used to control the dumping system, dilution systemand valves deactuator accurately by means of software program.(4) With this developed dumping system, the particle mass was successfully collectedand measured at different crank angle during the engine operation. The result showed thatthe curve of particle mass was single peak in form, which conformed to the theoreticcalculation. Consequently, it proved that the total cylinder dumping system was reasonableand suitable for the investigation of emission pollutants from modern diesel engine.