CAJ | 학술논문

使用便携排放测试系统测试了3辆带有SCR系统的公交车在实际运行条件下的NOX排放,对比喷射和不喷射尿素两种情况下的NOX排放因子,计算了SCR系统对NOX的降低率。结果表明：国Ⅳ柴油车由于其排气温度低,催化剂体积小,SCR系统对NOX的降低率最低,只当车速高于30 km/h以后才能逐步显现出催化效果,NOX平均降低率只有10%；国Ⅴ天然气车SCR系统对NOX 的降低率最高,它在低速时排气温度就很高,且NOX排放中NO2的比例较高,使其SCR系统对NOX 的降低率基本上不随车速而变化,NOX 平均降低率达85%；国V柴油车介乎两者之间,使其SCR系统对NOX 的降低率约为70%。至于NOX+HC排放,则是国V柴油车最低,国IV柴油车最高,国V天然气车由于其甲烷的排放量很高,使其NOX+HC排放接近而稍低于国Ⅳ柴油车。
사용편휴배방측시계통측시료3량대유SCR계통적공교차재실제운행조건하적NOX배방,대비분사화불분사뇨소량충정황하적NOX배방인자,계산료SCR계통대NOX적강저솔。결과표명：국Ⅳ시유차유우기배기온도저,최화제체적소,SCR계통대NOX적강저솔최저,지당차속고우30 km/h이후재능축보현현출최화효과,NOX평균강저솔지유10%；국Ⅴ천연기차SCR계통대NOX 적강저솔최고,타재저속시배기온도취흔고,차NOX배방중NO2적비례교고,사기SCR계통대NOX 적강저솔기본상불수차속이변화,NOX 평균강저솔체85%；국V시유차개호량자지간,사기SCR계통대NOX 적강저솔약위70%。지우NOX+HC배방,칙시국V시유차최저,국IV시유차최고,국V천연기차유우기갑완적배방량흔고,사기NOX+HC배방접근이초저우국Ⅳ시유차。
NOX emissions from three buses with SCR systems are measured by using portable emission measurement system in real-world conditions, the NOX emission factors in both conditions ( with and without urea in-jection) are compared and their NOX reduction rates of SCR systems are calculated. The results show that the State-IV diesel bus has the lowest NOx reduction rate of SCR system due to its low exhaust temperature and less volume of catalyst, whose effects gradually become apparent only when vehicle speed is higher than 30km/h, with an average NOX reduction rate of only 10 %;the State-V CNG bus has the highest NOX reduction rate due to its high exhaust temperature even at low speed and higher proportion of NO2 in NOX emission, and its NOX reduction rate basically does not change with vehicle speed, resulting in an average NOX reduction rate of 85%; while the NOX reduction rate of State-V diesel bus is in-between with an average NOX reduction rate of around 70%. As for the emission of NOX+ HC, the lowest is the State-V diesel bus, the highest is the State-IV diesel bus, while the NOX+HC emission of State-V CNG bus, due to its high emission of methane, is close to but slightly lower than that of State-IV diesel bus.