双卷流燃烧系统的双燃料发动机燃烧排放特性

为解决因生物柴油粘度过大，以及低温燃烧导致的燃油雾化、燃烧性能和排放恶化等问题，利用AMESim软件和AVL_FIRE软件对发动机燃烧室进行双卷流（DS）改造，对喷油提前角、喷孔直径进行优化匹配。结果表明:双卷流（DS）燃烧室燃油分布更加均匀，在运行范围内燃烧速率和功率比浅盆型燃烧室具有更大的优势；同时在加快燃油扩散速率和提高空气利用率方面具有显著的作用；在提高发动机动力性和经济性方面具有明显的优势。采用DS燃烧室、喷油提前角20.6°、喷孔直径0.28 mm组合结构形式的柴油机，其NO排放比原机降低81.83%，指示功率比原机降低7.73%。研究结果可为船用柴油机双燃料低温燃烧性能优化提供一定的指导依据。

Optimization of Dual Fuel Combustion Emission Characteristics Based on Dual Swirl Combustion System

In order to solve the problems of fuel atomization,combustion,performance and emission deterioration caused by the excessive viscosity of biodiesel at low temperature combustion,the engine combustion chamber was modified with double swirl (DS) by using AMESim and AVL_FIRE software,and the injection advance angle and the diameter of orifice were optimized and matched.The results show that the DS combustion chamber has more uniform fuel distribution,greater combustion rate and power than the shallow basin combustor in the operating range,and has a significant role in accelerating the fuel diffusion rate and improving the air utilization rate,which bring about obvious advantages in improving the power and economy.The diesel engine with DS combustion chamber,injection advance angle of 20.6°,and nozzle diameter of 0.28 mm has a lower NO emission of 81.83% and indicated power of 7.73% than the original engine.The results can provide some guidance for the optimization of low temperature combustion performance of marine diesel engine.