Effects of injection parameters on performance at low loads of a spark-ignited direct injection heavy-oil engine

An experimental study on the influences of fuel injection parameters on the engine performance was carried out on a two-stroke engine with low pressure air assisted injection technology, and the effects of inject end time and excess air ratio on engine power, fuel economy and emission performance were studied under the conditions of middle speed under small load. Test results show that at the 10% throttle opening condition, with the end of the inject advance, the power first increases, then decreases, and the fuel consumption first decreases, then increases, and the HC and CO emissions are reduced. When mixed gas is diluted, the power increases, the fuel consumption is reduced, and the HC and CO emissions are reduced significantly. At the 20% throttle opening condition, with the end of the inject advances, the power increases, the fuel consumption decreases, HC emissions have a small decrease, and CO emissions have a small increase. When mixed gas is diluted, the fuel consumption is reduced, the HC and CO emissions are reduced greatly, and the maximum power appears in the stoichiomtric ratio.