Experiment of injection strategy effect on RCCI combustion

To analyze the effects of fuel injection strategies on the ignition performance and combustion performance of reactivity controlled compression ignition（RCCI）combustion, the experimental investigation was carried out with gasoline and diesel/hydrocatalytic biodiesel（HCB） in an optical engine. The results show that diesel/gasoline RCCI combustion requires higher inlet temperature and higher ignition delay than HCB/gasoline combustion. With the increasing of inlet temperature, the combustion phase is advanced, and the ignition delay is decreased. When the proportion of diesel oil in the total energy of the fuel cycle is increased from 30% to 40%, the pressure in cylinder is increased, and the influence of inlet temperature on combustion is decreased. In the HCB/gasoline RCCI combustion model, the sensitivity of inlet temperature to the combustion process is decreased when the injection time of HCB is delayed from-30.0° to-20.0° of the crankshaft angle after the intake top dead center. In the optical engine test, the higher inlet temperature is conducive to achieve stable RCCI combustion. When the inlet temperature is lower than 30 ℃, stable ignition combustion can be achieved by delaying the injection time of high active fuel or increasing the proportion of high active fuel to control the combustion phase.