Abstract:

The effects of the blending fraction of gastoliquid(GTL) fuel in the GTL/diesel blended fuel on the combustion characteristic of a small diesel engine under steady operating conditions and transient conditions of fixed speed and increasing torque were studied experimentally using a homemade transient operation control and measure system for diesel engine. The results showed that the effects of the GTL fraction in the blended fuel on the combustion parameters demonstrate a similar tendency under steady and fixed speed and increasing torque operating conditions. Increase of GTL fraction leads to advanced ignition start, shorter ignition delay period, shorter premixed combustion period, reduced incylinder peak combustion pressure and reduced heat release rate. All these changes are good for the reduction of NOx emissions and combustion noise. Adding a little of GTL fuel into diesel fuel increases the combustion duration of the diesel engine, but the duration decreases with the increase of the GTL fraction. The combustion duration of the engine using pure TGL fuel is equivalent to that using pure diesel fuel.

Key words: power machinery and engineering, diesel engine, transient operation condition, gas-to-liquid(GTL)/diesel blended fuel, combustion, emission