The combustion and exhaust emission characteristics were investigated in a dimethyl ether(DME) and liquefied
petroleum gas(LPG) fueled homogeneous charge compression ignition(HCCI) engine. The injection strategy of change of
injection locations was tested under various injected fuel quantities and injection timings. The indicated mean effective
pressure(IMEP) and amount of nitrogen oxides(NOx) tended to increase as injection quantities of DME and LPG were
augmented, regardless of injection location. When the injection timing was close to the top dead center(TDC), the amount of
hydrocarbon(HC) was increased in case of DME direct injection with LPG port injection, but decreased in case of LPG direct
injection with DME port injection.
The experimental results show that DME direct injection with LPG port injection is effective on the hear release rate control,
IMEP increase, and NOx reduction. The less amount of HC could be obtained in case of LPG direct injection with DME port
injection than DME direct injection with LPG port injection