Performance and emission characteristics of a gas to liquid fuelled engine

The objective of the study is, through investigation of visualization and an engine test, to pursue a lower emission engine using GTL (gas to liquid) while maintaining thermal efficiency and fuel consumption. A sulphur-free (<13 ppm) diesel fuel was used as the reference fuel, and the characteristics of the GTL diesel fuel were investigated. As a physical property, the GTL fuel has approximately the same cetane value as the diesel but has low values of PAHs (polycyclic aromatic hydrocarbons), boiling point, density, viscosity, and surface tension. In visualization of spray and combustion, images were taken using a high-speed video camera and analysed by their penetration and evaporation characteristics in comparison with current diesel fuel. Also, in an engine test, a heavy-duty diesel engine which has six-cylinder 11.15 litre displacements was used to test the performance. The results showed that mixture formation of the GTL fuel is faster than that of diesel fuel, depending on the physical properties. In the engine test, a considerable reduction in PM (particulate matter) emission was observed, due to the enhanced fuel atomization and air entrainment, and a reduction in NO_x emission can be achieved without deteriorating b.s.f.c. (brake specific fuel consumption).