内河船舶柴油机的实际排放特征

利用由SEMTECH-DS和ELPI组成的PEMS(车载排放测试系统),对京杭运河江苏段具有代表性的12艘内河船舶进行实际排放测试,分析不同工况下CO、HC、NO_x和PM的排放. 结果表明:巡航工况下CO、HC和PM排放速率分别为0.093、0.019、0.018g/s,低于进、出港工况；而NO_x排放速率为0.347g/s,分别为出港和进港工况的1.66和2.90倍；不同工况外排NO占NO_x比例不同,其中巡航工况中外排NO所占比例最大(达到96.7%),而出港和进港工况则分别为93.6%和93.1%. 随着负荷增加,船舶 CO、HC、NO和PM的排放浓度增大,高负荷下CO、HC、NO_x、PM的排放浓度比低负荷分别增高89.23%、29.51%、44.72%和229.49%. 由颗粒物的粒径分布可知,3种工况下颗粒物数浓度的粒径分布呈双峰分布,分别对应核模态和积聚模态,粒径<120nm的颗粒物数浓度占总浓度的99.84%以上,PM_2.5数浓度占PM₁₀比例均超过99.9%. 

Emissions Characteristics of Diesel Engines for Inland Waterway Vessels in China

Transient mode emissions from twelve inland ships were measured using a portable emissions measurement system (PEMS). The results show that the emissions of CO, HC, and PM during cruise mode were 0.093,0.019, and 0.018g/s, respectively, lower than the emissions in maneuvering and departure modes. In contrast, the NO_x emission factor in cruise mode was 0.347g/s, which was 1.66and 2.90times of the emissions in maneuvering and departure modes, respectively. The ratios of NO to NO_x varied under different conditions. The proportion of NO was maximum in cruise mode (reaching 96.7%), while the proportions in maneuvering and departure modes were 93.6% and 93.1%, respectively. CO, HC, NO, and PM emissions from the vessel increased with load; the emissions concentrations in high load mode were 89.23%,29.51%,44.72%, and 229.49% higher, respectively than those in low load mode. Particle number (PN) distribution analysis indicated that the number distribution showed a double peak logarithm distribution consisting of accumulation mode/coarse mode and nucleation mode/accumulation mode. Particles smaller than 120nm consisted of 99.84% of all particles by number. Among PM₁₀ particles, 99.9% were PM_2.5.