Numerical Study On The Performance Of Dual-fuel Marine Engine

With the energy crisis and the environmental pollution problems caused by the emissions from the engines, using natural gas as an alternative fuel is causing the industry’s attention. Especially for the shipping business, which is suffering from soaring fuel prices and increasingly stringent emission limits, the research and application of the natural gas-diesel dual fuel engine becomes necessaryIn this paper, MAN6S50MC-C diesel engine is used as a prototype. On this basis, calculation models of a2-Stroke Directly-injected Dual-Fuel Engine and a2-Stroke Low Pressure Dual-Fuel Engine are set up after adjusting relevant parameters by using AVL BOOST software. Then the Performance of the engines and the influencing factors are analyzed.The results reveal that for the2-Stroke Directly-injected Dual-Fuel Engine, as the starting time of gas injection delays,the highest temperature,the highest pressure in the cylinder and the generation rate of NOx decrease while the equivalent fuel consumption rate increases; as the duration of the gas injection decrease, highest pressure in the cylinder and the generation rate of NOx increase while the equivalent fuel consumption rate decreases. For2-Stroke Low Pressure Dual-Fuel Engine, as the starting time of the fuel injection delays.The highest pressure in the cylinder and the generation rate of NOx decrease, while the equivalent fuel consumption rate increases. As the rate of replacement increase, the highest temperature, the highest pressure in the cylinder, the generation rate of NOx decrease,while the equivalent fuel consumption rate increase. The latter engine has a better performance in decreasing the emission of NOx.The theory basis for design and improvement of dual-fuel marine engine is provided by analyzing the performance of the two kinds of the dual-fuel engine.