536 / 2019-01-14 10:54:27

Study on the Influence of Scavenging Port Structure on the Performance of Low Speed Dual Fuel Engine\扫气口结构对低速双燃料发动机性能影响的研究

low pressure injection; dual fuel engine; scavenging port; height; position\低压喷射；双燃料发动机；扫气口；高度；位置

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随着经济全球化的发展，船舶航行排放的尾气对全球空气质量产生了重大影响。面对日渐严格的排放法规，双燃料发动机技术以其良好的排放性已成为船舶发动机重要的发展方向。本文以某型船用二冲程低速双燃料发动机为研究对象，利用GT-power软件建立该发动机一维仿真模型，并在此基础上研究了扫气口高度和位置对发动机性能和排放的影响。
研究结果表明，不同负荷下扫气口高度和扫气口位置对双燃料发动机性能的影响也有所不同。从不同工况来看，扫气口高度过小则导致扫气效果不足，残余废气系数较高，最大燃烧压力降低，油耗升高；扫气口高度过大则引起扫气口倒流，同样也造成较高的残余废气系数和油耗；若扫气口位置过低，空气流量和空燃比较低，缸内最高燃烧温度较高；位置过高则引起扫气口倒流，造成偏高的残余废气系数和油耗。
本文所得到的研究成果可以为船用低压双燃料发动机的设计、优化提供参考，并为进一步提高发动机性能和降低排放打下基础。
With the development of economic globalization, the exhaust emissions from ship navigation have had a major impact on global air quality. In the face of increasingly strict emission regulations, dual-fuel engine technology has become an important development direction for marine engines with its good emission. In this paper, a two-stroke low-speed dual-fuel engine for marine use is studied. The one-dimensional simulation model of the engine is built by GT-power software. Based on this, the influence of the height and position of the scavenging port on engine performance and emissions is studied.
The results show that the effect of scavenging height and scavenging position on the performance of dual fuel engines under different loads is also different. From different working conditions, the scavenging port height is too small, resulting in insufficient scavenging effect, high residual exhaust coefficient, maximum combustion pressure, and increased fuel consumption. Excessive scavenging height causes the scavenging port to reverse, which also causes higher Residual exhaust gas coefficient and fuel consumption; if the position of the scavenging port is too low, the air flow and air-fuel ratio are relatively low, and the highest combustion temperature in the cylinder is high; if the position is too high, the scavenging port is reversed, resulting in a high residual exhaust gas coefficient and fuel consumption.
The research results obtained in this paper can provide reference for the design and optimization of marine low-pressure dual-fuel engines, and lay a foundation for further improving engine performance and reducing emissions.