我国重型柴油货车黑碳排放影响因素分析

Analysis of Parameters Influencing Black Carbon Emissions from Heavy-Duty Diesel Trucks in China

柴油车的黑碳排放对空气质量和气候变化有重要影响,但我国柴油车黑碳排放清单编制仍有较大局限性.为进一步提高柴油车黑碳排放清单编制精度,采用整车转毂台架和热光折射的方法研究不同排放标准、行驶工况和负载状况对重型柴油货车黑碳排放的影响.结果表明:我国排放标准升级对重型柴油货车的黑碳排放有重要影响,从国Ⅰ、国Ⅱ排放标准升级到国Ⅲ、国Ⅳ和国Ⅴ排放标准,黑碳在颗粒物中的占比由41%左右逐步提至72%左右.行驶工况对重型柴油货车的黑碳排放也有一定影响,车辆在C-WTVC(中国重型商用车燃料消耗量测试工况)下的黑碳排放占比较VECC(重型车典型道路行驶工况)下高5%~10%.与半载状态相比,重型柴油货车在满载状态下黑碳排放占比更高,国Ⅲ、国Ⅳ重型柴油货车满载状态下黑碳排放占比较半载状态高7%~8%,国Ⅱ重型柴油货车满载状态下黑碳排放占比较半载状态高15%左右.研究显示,柴油货车黑碳排放清单编制要综合考虑排放标准、驾驶特征、负荷状况等对黑碳排放的影响,不宜使用固定系数利用颗粒物排放因子外推黑碳排放因子.

Black carbon(BC)emissions from diesel vehicles have serious impacts on air quality and climate change.However,there are still many limitations in the development of diesel vehicle BC emission inventory in China.In order to improve the accuracy of black carbon emission inventory of diesel vehicles,the effects of different emission standards,driving cycles and load conditions on BC emissions from heavy-duty diesel trucks(HDDT)were analyzed by using heavy duty truck chassis dynamometer sampling and thermo-optic reflection black carbon measurement.The results show that upgrading the emission standards had an significant impact on the BC emissions of HDDT.Compared with the trucks with China Ⅰ and Ⅱ,the proportion of BC in particulate matter(PM)of the tested trucks with China Ⅲ,China Ⅳ and ChinaⅤgradually increased from 41% to 72%.The driving cycles also had influence on the BC emissions.The BC ratios on C-WTVC driving cycle(the driving cycle adapted to the fuel consumption test for heavy-duty commercial vehicles in China)were 5%-10% higher than those on VECC driving cycle(the typical roads driving cycle for heavy-duty commercial vehicles in China).The BC ratios of HDDT with full loads were higher than the half-loaded ones.For China Ⅱ heavy trucks,the differences were about 15%.The BC ratios of China Ⅲ and Ⅳ heavy trucks at full load were about 7%-8% higher than those at half loads.Emission standards,driving cycles and load conditions should be considered comprehensively when determining the BC emission factors.Applying a fixed ratio in PM to calculate BC emission factors can introduce large uncertainties in the BC emission inventory.