Influence of gas-to-liquid fuel on the combustion and pollutant emission characteristics

摘要

The purpose of this work was to investigate the combustion performance and the pollutant emission characteristics of gas-to-liquid fuel in a passenger car's diesel engine. In order to perform this study, the test facilities were set up on a 1.6 1 four-cylinder compression ignition diesel engine with a common-rail injection system. Gas-to-liquid fuel combustion under a high-engine-load condition was compared with conventional diesel and biodiesel derived from soybean oil. The performance test results revealed that the gas-to-liquid fuel shows more rapid ignition than diesel and biodiesel do because of its high cetane number. The rates of increase in the combustion pressure in gas-to-liquid fuel and biodiesel were smaller than that in diesel, and the maximum rate of heat release from gas-to-liquid fuel was the lowest among the three test fuels. In terms of emission analysis, gas-to-liquid fuel shows a slight decrease in the nitrogen oxide emissions and significant reductions in the hydrocarbon and the carbon monoxide emissions compared with other test fuels. Meanwhile, the combustion of gas-to-liquid fuel indicates a lower concentration of soot emissions than those from conventional diesel but slightly higher than those from biodiesel owing to the variation in the low heating value parameter.