CAJ | 학술논문

采用1台满足国Ⅳ标准的高压共轨、涡轮增压中冷柴油机，研究了在加装尿素选择催化还原器（urea-SCR）前后的NO2排放特性。通过测量urea-SCR前后排气温度、压力、氮氧化物（NOx ）和二氧化氮（NO2）排放量等参数，研究了NO2对柴油机 urea-SCR性能的影响。分析结果表明：随着 urea-SCR前排气温度上升，NOx 中NO2百分比降低；当发动机转速一定时，NO2比例随扭矩的增大而降低；当发动机扭矩一定时，NO2比例随转速的上升呈现“V”形变化趋势；当urea-SCR前排气温度为255℃时，urea-SCR转化效率受NO2比例的影响波动性较大；在335℃时转化效率和NO2比例的变化趋势一致性最大。
채용1태만족국Ⅳ표준적고압공궤、와륜증압중랭시유궤，연구료재가장뇨소선택최화환원기（urea-SCR）전후적NO2배방특성。통과측량urea-SCR전후배기온도、압력、담양화물（NOx ）화이양화담（NO2）배방량등삼수，연구료NO2대시유궤 urea-SCR성능적영향。분석결과표명：수착 urea-SCR전배기온도상승，NOx 중NO2백분비강저；당발동궤전속일정시，NO2비례수뉴구적증대이강저；당발동궤뉴구일정시，NO2비례수전속적상승정현“V”형변화추세；당urea-SCR전배기온도위255℃시，urea-SCR전화효솔수NO2비례적영향파동성교대；재335℃시전화효솔화NO2비례적변화추세일치성최대。
For a turbocharged and intercooled State Ⅳ diesel engine with high-pressure common rail ,the NO2 emission before and after the urea-SCR was researched .Based on the measured exhaust temperature ,exhaust pressure ,NOx and NO2 ,the in-fluence of NO2 on urea-SCR performance was studied .The results show that the NO2/NOx ratio decreases with the increase of temperature before the urea-SCR .For the constant speed ,the NO2/NOx ratio decreases with the increase of engine torque .For the constant torque ,the NO2/NOx ratio shows the V-typed trend with the increase of engine speed .When the temperature be-fore the urea-SCR is 255 ℃ ,the influence of NO2 on SCR efficiency fluctuates .At 335 ℃ ,the trends of SCR efficiency and NO2 fraction have the best consistency .