一种实现组合燃烧模式闭环控制的宽域氧传感器控制器

摘要

To reduce the fuel consumption and thermal load of heavy duty turbocharged CNG engine and make the engine work in the learn-burn area, the UEGO sensor controller was designed. Based on the controller, the rapid lean-burn control was realized. The controller recorded the signals of UEGO, engine speed and intake pressure and then calculated. The air-fuel ratio for current condition was acquired and compared with the target air-fuel ratio and then the state of current mixture could be judged and converted into the electrical signal. Finally, the simulated switch-type oxygen signal was written into CNG engine ECU with stoichiometric air-fuel ratio in real time. The results show that the controller can realize the close loop control of CNG engine stoichiometric combustion and lean-burn combustion based on the ECU of stoichiometric air-fuel ratio control.%为了降低重型增压燃气发动机燃料消耗和热负荷,并使之运行在稀薄燃烧区,设计了一种宽域氧(UEGO)传感器控制器和基于此控制器快速实现稀薄燃烧控制的方法.该控制器通过采集UEGO、发动机转速和进气压力等信号,精确计算得到当前工况下的空燃比值,并与可标定的目标空燃比值进行比较,判断当前混合气的浓稀状态,向基于理论空燃比控制的燃气发动机ECU实时输出模拟的开关型氧传感器信号.试验表明:控制器结合基于理论空燃比控制的ECU能实现燃气发动机理论空燃比燃烧和稀薄燃烧组合模式的闭环控制.