烟塔合一项目大气评价等级和评价范围估算的季节选择

Seasonal selections of atmospheric scale and scope evaluation in the natural draft cooling tower project

《环境影响评价技术导则大气环境》(2008)中推荐了大气评价等级和大气评价范围的估算模型SCREEN3,SCREEN3模型可以用于点源、面源、线源及体源等污染源的大气评价等级和大气评价范围的估算,但不适用于烟塔合一项目。本文利用德国AUSTAL2000模型和2016年的四季气象观测资料,对216组气象条件下的下风向轴线的各污染物浓度进行计算,并选取不同季节各污染物的最大地面浓度占标率(Pi)和地面浓度达标准限值的10%时对应的最远距离D10%,估算不同季节的大气评价等级与评价范围。结果表明,对于烟塔合一项目,采用四季气象条件估算的大气评价等级基本均为二级;但对于大气评价范围,采用不同季节气象资料的估算结果存在一定差异,夏季最大,春、秋季次之,冬季最小。

"The Guidelines for Environmental Impact Assessment of atmospheric environment"(version2008)has recommended SCREEN3estimation model for the atmospheric evaluation scales and scopes.The model can be used for the estimation of atmospheric evaluation scales and scopes of point sources,area sources,line sources and body sources,but can’t be used for the projects of natural draft cooling towers(NDCT).AUSTAL2000model and meteorological observation data in2016were used to simulate the pollutant concentrations on various leeward axials under1296groups of meteorological conditions.Then the seasonal maximum ratios of ground concentrations(Pi)for different pollutants and the longest distance(D10%)corresponding to the10%of the standard limit of the ground concentrations were selected to evaluate the seasonal atmospheric scales and scopes.The results show that the atmospheric evaluation scales of NDCT project are most second scale.The atmospheric evaluation scopes vary with the estimation of seasonal meteorological data,with the largest one in summer,the second largest ones in spring and autumn,and smallest one in winter.