Experimental Investigation Of HCCI Gasline Engine Based On Various Camshafts And Design Of The Prototype Engine

HCCI(Homogeneous Charge Compression Ignition) may be considered as ahybrid of the traditional spark ignition and the compression ignition combustionsystems. HCCI combustion can be generate power with hign thermal efficiency andlow NOx and particulate matter.In order to gain internal exhaust gas recirculation using bigger negativeoverlapped angle of inlet and exhaust to achieve gasoline engines' HCCI combustion.Special inlet and exhaust's camshafts with small durative angle were designed andmanufactured. And an experimental setup was built based on a Ricardo's gasolineengine, which included coolant and oil temperature control systems,electronic controlunit and measurement & controll and analysis systems.Steady–state HCCI combustion could be achieved by using the camshaftsmentioned above. The influence of inlet and exhaust's timing and lift's on HCCIcombustion was researched. The experimental results show that exhaust valve closingtiming has a great influence on internal exhaust gas recirculation ratio and HCCIcombustion. While inlet vavle opening timing has a little influence on HCCIcombustion. The results also show that change in vavle lift can extend HCCI'soperation ranges. The camshaft with high lift cam configuration can extend HCCIoperation ranges to high loads and speeds, and camshaft with low lift one can moveHCCI operation ranges to low loads and speeds. Therefor, it is necessary to developan HCCI engine with fully variable vavle actuation.A new cylinder head which could mount BMW's VANOS and Valvetronicscomponents for fully variable vavle actuation was designed. The cylinder head will befixed on the Ricardo's gasoline engine, and a prototype gasline engine to researchHCCI combustion will be estabilished, which will offer a good base for researchingHCCI combustion and mode change between HCCI and SI(Spark Ignition)combustion.