Quantification Of Pollutant Emissions From Non-road Construction Machinery Based-on Real-world Measurement

With the rapid urbanization and infrastructure construction in China,the use of construction machinery is increasing correspondingly.At present,non-road construction equipment（NRCE）has become an important source of urban air pollution.Analyzing the pollutant emission characteristics and accurately quantifying emission inventory of NRCE is important to improve urban air quality management.In this study,a SP-PEMS（Synchronous Platform based on PEMS）was built to measurement transient emission of 12excavators and 9 wheel loaders.The real-world measurements were conducted under cold/hot start,idling,moving and working mode.We analyzing the emission characteristics of CO,HC,NO_X,PM_2.5and BC.Then,establishing the pollutant emission inventory of NRCE in China in 2019.Firstly,the pollutant emissions of excavators and loaders were significantly affected by operating conditions.The emissions of CO,HC,PM_2.5and BC have obvious peaks under cold/hot start mode.The average emission rate of pollutants under moving and working mode is 1.2-12.5 times of idle mode.For every 10%increase in engine load,emissions of CO,NO_X,PM_2.5and BC increase by 1.7%-151.8%correspondingly.In addition,BC and PM_2.5have a good correlation（R²>0.48）.Furthermore,the ratio of BC/PM_2.5for engine using MI（mechanical fuel supply technology）and EI（electronic fuel injection technology）is 0.36±0.07 and 0.72±0.07 under moving mode,and under working mode is 0.33±0.05 and 0.70±0.06,respectively.Secondly,this study quantified the fuel-based EFs（Emission factors）of CO,HC,NO_X,PM_2.5and BC for excavators and loaders,and calculated the comprehensive EFs according to the time distribution of operation mode.The results show that pollutant emission factors are obviously affected by operating modes,emission standards and engine rated power.In comparison with other studies,we found that 1)the EFs of NO_Xand PM based on real-world measurement were 3.2%-114.3%and 43.7%-89.2%higher than the guideline,respectively;2)The BC EFs of NRCE is 1.2-7.7 times that of EC.Finally,this study established the emission inventory of NRCE in China in 2019,which based on EFs,populations and activity level.The emissions of CO,HC,NO_X,PM and BC were 101.1,191,241.6,174 and 6.9 million tons,respectively.Excavators,loaders and forklifts contribute the most to emissions.The NRCE conform to standⅡand standⅢemission accounted for more than 70%of the total emissions.This study comprehensively analyzed the emission characteristics and quantified emission inventory for NRCE,and provided important data support for the emission control.