Research On The Contribution And Mitigation Strategies Of Shaanxi Thermal Power Industry’s Environmental Air Quality

Shaanxi Province,especially northern Shaanxi,as the national energy base and the source of"power transmission from west to east",has been on the rise in thermal power installed capacity.As a key area of air pollutant emission,the emissions of SO₂and NO_Xin thermal power plant exceeded 25%and the emissions of particulate matter exceeded 10%from 2011to 2015.In terms of ambient air quality,Shaanxi Province,especially most areas in Guanzhong and Northern Shaanxi,is an area with substandard ambient air quality.Therefore,it is of great significance to explore the contribution of thermal power industry to ambient air quality and the effect of pollutant emission reduction in thermal power industry on improvement.This paper takes the pollutant emission of thermal power industry in Shaanxi Province as the research object,and analyzes its air pollutant emission characteristics by establishing the thermal power emission inventory in Shaanxi Province in 2018;By establishing WRF-CALPUFF model,the contribution of thermal power air pollutant emission to ambient air quality is simulated and analyzed.Through scenario analysis,the effect of reducing air pollutants in thermal power industry is analyzed.Come to the following conclusions:（1）Based on the material balance algorithm and emission factor method,the emission source list of thermal power in Shaanxi Province in 2018 is established,and the emission characteristics of thermal power air pollutants in 2018 are analyzed by cities and seasons according to the installed capacity,control measures and coal quality.It is pointed out that units above 250MW are the main contribution source of air pollutant emission in thermal power plants,but units below 75MW have higher pollutant emission per unit coal consumption.The best control measures for SO₂,NO_xand particulate matter in existing thermal power enterprises are limestone-gypsum desulfurization process,LNB+SCR+SNCR combined denitration technology,bag dust removal+electrostatic secondary dust removal technology.Yulin City is the most prominent in thermal power installation and air pollutant emission,and its seasonal operation and pollutant emission are relatively balanced.（2）On the basis of simulating the meteorological simulation of Shaanxi Province in 2018with WRF model and using CALPUFF air quality model,the pollutant concentration distribution analysis of thermal power emission in four representative months of the whole province is simulated.The results show that,in terms of spatial distribution,the thermal power industry contributes a lot to the pollutants in the ambient air in northern Yulin,southern Yan’an and central Guanzhong.In time distribution,the concentration contribution of thermal power industry in different months is January>April>July>October.The contribution of thermal power enterprises to the existing 14 state-controlled and provincial-controlled ambient air stations varies from 0 to 1.5%,and the contribution rate of thermal power enterprises is low,which is mainly due to the spatial difference and separation between existing monitoring stations and thermal power enterprises.（3）Combined with the thermal power control policy of Shaanxi Province and the relevant requirements of the"14th Five-Year Plan",according to the two scenarios of efficient desulfurization,denitrification and enhanced desulfurization,denitrification and dust removal,the existing thermal power enterprises were reformed for emission reduction,and the pollutant emission reduction effect and its improvement effect on ambient air quality were analyzed.The results show that the emission reduction effect of the two scenarios is obvious,but the improvement effect of ambient air quality is low due to the spatial heterogeneity of existing monitoring stations and thermal power enterprises.