Study of the performance in dual fuels 50% gasoline -50% NG and single original fuels and comparison in part load

One of the most efficient methods to reduce emissions and fuel costs of SI engines in petrol case, is the use of combined gasoline and NG. The ability of an engine is usually expressed with maximum power and maximum torque output of full-load state, but the operating time of the engines with full-load is less than that of part-load time. Therefore, studying the performance of the engine with a new mixed fuel (dual-fuel) requires studies under full-load and part-load. In the present work, dual gasoline-NG fuel with equal mass ratio together with single original fuel modes in full-load and a few part-load at 1800 rpm, 10.12 compression-ratio and almost stoichiometric equivalence-ratio have been taken into consideration in a SI single-cylinder research engine. In each load with a certain fuel, the spark­ advance was changed with 2°CAbTDC step and from obtained output and in-cylinder results, the optimum spark timing was determined for that mode and load. The results at optimum advance showed that increasing engine load, the exhaust gas temperature almost linearly for G100 and G0 but nonlinearly for G50 enhanced. Also, in full-load, the HC of the G100 appeared to be noticeably larger than those of G50 and G0. Decreasing engine-load for G100, HC amount reduced, while those for G50 and G0 increased. By changing the load, CO content for G50 and G0 fuels changed slightly, whilst that for G100 changed significantly. These observations emphasize a serious attention to dual fuel study mode in part-loads.