Effects of fuel injection timing on combustion and emission characteristics of a diesel engine fueled with diesel-propane blends

In this paper, the effects of fuel injection timing on fuel consumption, combustion, and emission characteristics fueled with diesel and diesel-propane blends in a single-cylinder diesel engine were investigated. The results showed that the effects of fuel injection timing on the performance of the engine exhibited the similar trends for both the diesel fuel and the diesel-propane blends. At the same engine speed and brake mean effective pressure, the specific fuel consumption decreases when operating on the diesel-propane blends comparing with that on the diesel fuel. The peak cylinder pressure, the maximum heat release rate, the proportion of the premixed heat release, the maximum cylinder mean gas temperature, the duration of cylinder mean gas temperature over 1500 K, and NOx emission decrease while retarding the fuel injection timing. The total combustion duration, the emissions of CO, HC, and smoke increase while retarding the fuel injection timing. For the same engine speed, the engine load and the fuel injection timing, the cylinder peak pressure, the maximum heat release rate, the proportion of the premixed heat release, the maximum cylinder mean gas temperature, and NOx emission increase while increasing the propane proportion in the fuel blends. The total combustion duration, the CO, HC, and smoke concentrations decrease while increasing the propane proportion in the fuel blends.