A Study of Compression Ignition Engine Operated by Various Biomass Fuels 912335
The engine performance, combustion characteristics and exhaust emission of pre-chamber type compression ignition engine operated by various biomass fuels were investigated experimentally. The biomass fuel investigated in this report are an emulsified fuel made with gas oil and hydrous ethanol or hydrous methanol, an emulsified fuel made with hydrous methanol and rape-seed oil, and neat rape-seed oil, and gas oil.
There are small deviations of the experimental results between the biomass fuels, however, the general tendencies of the engine performances and exhaust gas characteristics operated by biomass fuels are as follows:
The brake thermal efficiency during biomass fuel operation becomes maximum at a certain injection timing as well as those of the gas oil operation. And this injection timing is advanced with increasing the biomass content in the fuel. The more fuel injection timing approaches the top dead center, in other word, the more retarded injection timing, and the more the biomass content in the fuel, the smoke density and total hydrocarbon concentration in the exhaust gas are remarkably decreased.
Since the ignition lag at the biomass fuel operation is longer than that at gas oil operation, the premixed combustion of the former is higher and consequently the maximum rate of heat release, the maximum rate of combustion pressure rise and the maximum combustion pressure of the former are higher and its combustion noise (sound pressure level:SPL) is louder than those of later.