Improving Performance For LN2V22 Swirl Chamber Diesel Engine

Swirl chamber diesel engine has good performance, low emissions and low cost, which obtained great development and wide application in our country, and plays an important role in national economy. As power of automobile, tractor, agricultural water pump, harvester, small engineering machinery, small ships, it is widely used in transportation, agricultural, industry, and other departments. Despite facing the fierce competition with direct injection(DI) diesel engine and spark ignition engine, through continuous progress, it still has strong vitality, especially in small, high-speed, naturally aspirated engine field.In recent years, more and more requirement was obeyed to follow the strict emission standards for engines. While swirl chamber diesel engine has unique combustion system advantage, which leads to low emissions, low noise and good adaptability to high speed, favored by small agricultural machinery. So the research on the swirl chamber diesel engine with low emission and high performance has an important academic significance and practical value in engineering.This paper is based on the diesel engine in cooperation with business development on the basis of swirl chamber diesel engine with LN2V22, through the experimental analysis and then transform the engine structure, the research focused on the economy and power performance, by analyzing the swirl chamber diesel engine performance to find an improvement method. This test first performed on the original engine to obtain the performance parameters, the results show that there is a poor volumetric efficiency, and the specific fuel consumption is too high, also the high cylinder pressure increase rate lead to rough work and bad performance, such as lack of power or can’t meet the design requirements. By analyzing the original engine parameters, finding that one reason of the poor volumetric efficiency is the unreasonable design of intake/exhaust port, to match the fuel supply system. Agreed with the manufacturer, the optimization of the intake/exhaust port on the original engine was carried out, then diesel engine performance improved, but its economy and power performance is still unable to meet the design requirements. Therefore, on the basis of the optimization of intake/exhaust port, the optimization of the valve train was performed, and matching with fuel supply system to further improve the performance of diesel engine, and finally meet the design requirements.The test was performed on the LN2V22 original engine and the improved engine. The results of the original engine shows that the maximum power is13.8 kW, specific fuel consumption is 366.8 g/(k W h), the highest cylinder pressure increase rates 1.49 MPa/°CA; while by optimizing the intake/exhaust port, the power reached to 15.1 kW, specific fuel consumption decreased to 320.0 g/(kW h), cylinder pressure increase rate decreased to 0.74 MPa/°CA; Through the optimization of valve train the final power reached to 15.8k W, specific fuel consumption decreased to 294.0 g/(kW h), the cylinder pressure increase rate decreased to 0.52 MPa/°CA. Research shows that the intake air and the fuel supply system match with the diesel engine is the main factor of LN2V22 diesel engine performance, this paper can provide reference for the swirl chamber diesel engine performance optimization.