中国国道和省道机动车尾气排放特征

近年来,随着我国机动车保有量的持续增长,机动车排放已成为我国重要的大气污染物来源之一.现有的机动车排放研究多关注城市内的机动车大气污染物排放,针对城市间的大气污染物排放研究较少.我国城市间交通道路主要包括国道和省道,截止至2015年我国国道里程18.53万km、省道里程32.97万km,约占全国等级公路总里程的13%,因此开展我国国道和省道机动车大气污染物排放研究十分重要.本研究基于全国国道和省道交通监测站的年均监测数据,采用环境保护部发布的《道路机动车大气污染物排放清单编制技术指南(试行)》中的指导方法,计算了2015年我国国道和省道机动车的大气污染物排放清单,分析了污染物排放的时空分布特征.结果表明,我国国道和省道公路机动车排放的一氧化碳(CO)、氮氧化物(NO_x)、颗粒物(PM)和碳氢化合物(HC)排放量分别占全国机动车污染物总排放量的4.5%、27.9%、14.4%和7.7%;不同车型对国道和省道机动车大气污染物排放的分担率不同,其中大货车是NO_x、PM_(10)、PM_(2.5)的主要来源,摩托车是CO和HC的主要来源;不同道路类型中各车型的大气污染物排放分担率也不同,如高速路上大货车是NO_x、PM_(10)和PM_(2.5)的主要来源,普通道路上大客车和大货车是NO_x、PM_(10)和PM_(2.5)的主要来源.

Emission Characteristics of Vehicles from National Roads and Provincial Roads in China

In recent years, with the rapid increase in automobile volume, vehicle emissions have become one of the major emission sources of urban air pollution in China. In China, most of the national and provincial roads have been the channels that connect different cities. Up until 2015, the length of national and provincial roads have reached 1.85×10⁵ km and 3.29×10⁵km, respectively, accounting for 13% of the mileage of all classified highways. Therefore, active research on vehicle emissions from national and provincial roads between cities in China is of great significance. Few studies have been conducted on air pollutant emissions from intercity vehicles. In this study, emission characteristics of intercity vehicles were investigated based on traffic monitoring data and the "calculation guide of air pollutant emission for road vehicles". The results showed that the CO, NO_x, PM, and HC emissions accounted for 4.5%, 27.9%, 14.4%, and 7.7% of national vehicle emissions, respectively. There were significant differences in emission contributions among different types of intercity vehicles. Heavy trucks were major contributors to NO_x, PM₁₀, and PM_2.5 emissions and motorcycles contributed most to CO and HC. Furthermore, there were significant differences in emission contributions of vehicle types on different road types; the major contributor of CO and HC emissions was small passenger cars on expressways. Motorcycles were the main contributors to CO and HC emissions on ordinary roads.