大功率天然气燃料发动机空燃比控制方法

Air-Gas Ratio Control of High Power LNG Engine

以某大功率天然气发动机为研究对象,基于GT-Power仿真软件研究稳态状况下不同参数对气体发动机空燃比控制的影响。提出了采用空燃比裕度表征气体发动机空燃比控制可靠性的方法,并基于节气门和废气旁通阀实现空燃比分段控制。研究结果显示:减小涡轮喷嘴环面积或者采用MMPC、双脉冲管系可以提高该气体发动机的空燃比裕度。此外仿真计算还表明:随着环境进气温度与空冷后进气温度的升高,气体发动机空燃比裕度下降。因此,为了满足气体发动机的环境适应性,空燃比裕度必须足够大。

Based on GT-Power simulation software,research was carried out on a large power LNG engine to study the influence of varied parameters on the air-gas ratio control of gas engines under steady state.The method of characterizing the reliability of air-gas ratio control for gas engines with air-gas ratio tolerance was put forward.Air throttles and waste gate valves were used to realize air-gas ratio step control.The research results show decreasing the turbine nozzle area,or adopting MMPC or double-pulse pipes can increase air-gas ratio tolerance.Simulation results show that with the increase of both inlet temperatures from the environment and after the air-cooling,the air-gas ratio tolerance of gas engines decreases.Thus,to meet the environmental adaptation requirements of gas engines,the air-gas ratio tolerance has to be big enough.