过量空气系数和点火提前角对CNG发动机NOX排放性能的影响

Impact of Excess Air Ratio and Ignition Timing on CNG Engine Emissions

试验研究了过量空气系数和点火提前角对稀燃电控调压器式天然气发动机的燃烧以及排放的影响。试验过程对全工况的排放和动力进行了稳态优化。研究结果表明,在其他影响参数不变的情况下,随着点火提前角的减小和过量空气系数的增加,扭矩和NOX排放均降低。在匹配氧化型催化转化器后,各工况选取适当的点火提前角和过量空气系数可以满足国Ⅴ的排放标准。

The impacts of excess air ratio and ignition timing on combustion and emissions of lean burnelectronically controlled regulator natural gas engine were experimentally studied. The full steady-stateconditions of emissions and power were optimized in the experimental process. The results show that un-der the other influence parameters being equal, with decrease of the ignition advance angle and in-crease of the excess air ratio, the torque and NOXemissions were reduced. After matching the oxidationcatalyst, the appropriate ignition timing and excess air ratio can meet China Ⅴ emission standard in dif-ferent working conditions.