Study on Spark-ignited Two-stroke Direct Injection Heavy-oil Engines at Low Loads

An experimental study on the performances was carried out on a two-stroke engine with low pressure air assisted injection technology by aviation kerosene. The influences of ignition angle advance, end angle of air injection and excess air coefficient on the performance of the engine was studied under the conditions of 3000 r/min low loads. Test results show that: when end time of air injection is set to 50° and 80° before top dead center(BTDC), the increases of ignition advance angles may make the engine power increase and the fuel economy reduce. But, the increases may not be too much, or it will cause the increases of CO and HC. When the ignition advance angles are set to 15° and 30° BTDC, the engine powers, fuel consumptions and emission performances may be improved by the advances of the end time of the air injection. And, the rich mixture is beneficial to improve the power outputs, and the loan mixture is beneficial to reduce the emission.