HCCI engine fueled by woody biomass gas and city gas (effect of fuel composition)

Abstract

Autoignition and combustion characteristics of biomass gas and city gas 13A mixed fuels in a HCCI engine were investigated. A mock biomass gases consisting of H2, CH4, CO, N2 and CO2 were used assuming woody pyrolysis gases. Using a modified gas engine with high compression ratio pistons and an inlet air heating system, experiments were carried out. Influences of mixing ratio of two fuels on heat release and indicated thermal efficiency were investigated. Higher city gas 13A content make maximum value of rate of heat release lower at a constant equivalence ratio and a constant IMEP. The mixed fuel obtains higher indicated thermal efficiency and lower cyclic variation than biomass gas or city gas 13A only. Effects of H2 and CO contents of biomass gas were also investigated. It is clarified that H2 has a big influence on rate of heat release but CO does not.