利用Toolkit 4.5标定软件和电力测功机台架，采用ECM-OH6多点电控喷射系统，开展了降低重型增压中冷天然气发动机尾气中的NOx比排放值的试验研究。借助Horiba 7200系列排放测试设备，严格控制边界条件，分析得出降低NOx的优化策略与主要标定变量。试验结果表明：按照点火提前角、增压器WGCV阀开度、点火能量和精确空燃比控制的优化顺序能够快速降低NOx比排放，优化策略合理有效，具有较高的工程应用价值；标定变量优化的过程应该兼顾污染物浓度和排温的变化趋势，最终确定标定变量的优化范围。
With the calibration software of Toolkit4.5 and electrical dynamometer test bench, the experiment of reducing NOx specific emission for heavy-duty turbocharging and intercooling natural gas engine was conducted by using multipoint electronic control injection system of Woodward ECM-OH6 controller. Through high performance emission measurement equipment of Horiba 7200 series and the strictly controlled boundary conditions, the optimization strategy for NOx emission and main calibration variables were analyzed and determined. The test results show that the sequential optimization of ignition advance angle, WGCVopening, ignition energy and accurate airfuel ratio control can reduce NOx specific emission rapidly. Therefore, the optimization strategy is reasonable and effective and is of high value for engineering applications. The optimization process of calibration variables should also take pollutant concentration and emission temperature into consideration and the optimization scope of calibration variables is ultimately determined.
