Z6170ZLC型LNG-柴油双燃料船用增压发动机性能仿真分析

LNG-柴油双燃料发动机同时存在预混合燃烧和缸内压缩点火燃烧,其性能与原型柴油机有较大的差别.文中基于AVL-Boost发动机性能仿真软件,采用等热值当量处理不同比例的混合燃料,考虑了不同工况预混合LNG燃料对充气效率的影响,采用双韦伯函数燃烧放热率模拟不同比例混合燃料的预混合燃烧和缸内压缩点火燃烧,对比分析了LNG-柴油双燃料增压发动机和原型柴油机的动力性和经济性.研究表明：（1）预混合LNG燃料对充气效率的影响不会导致单点预混合LNG-柴油双燃料增压发动机的动力性下降;（2）相比较原型柴油机,各负荷工况双燃料发动机的燃油经济性均有下降,低负荷工况燃油经济性下降更为严重;（3）高负荷工况掺烧过高比例的LNG燃料将导致气缸压力急剧增加.

Performance Simulation and Analysis of Z6170ZLC Marine Turbocharged Engine with LNG-Diesel Duel Fuel

As premixed combustion and compression ignition combustion both exist in LNG-diesel dual fuel engine,there are large differences in this dual fuel engine compared with the performance of the prototype engine.Based on the AVL-boost software and considering the influence of premixed LNG fuel in different conditions on volumetric efficiency,this paper deals with different ratios of mixed fuel by using heat value equivalent treatment,simulate premixed combustion and compression ignition combustion with different mixing ratio of the mixed fuel double by using Weber heat release rate,and also makes a comparative analysis of the dynamic and economic performances between LNG-diesel dual-fuel turbocharged engine and prototype diesel.Studies show that：（1）the impact of pre-mixed LNG fuel on volumetric efficiency does not decrease the power performance in a single point of premixed LNG-powered dual-fuel turbocharged diesel engine;（2）compared with the prototype diesel engines,dual-fuel engine’s economic performances have declined in every condition,especially in the low load conditions;（3）blending high proportion of LNG fuel in high load conditions will lead to a sharp increase in the cylinder pressure.