估算模式AERSCREEN的参数敏感性研究

Sensitivity analysis on the parameters of model AERSCREEN

《环境影响评价技术导则大气环境》(HJ2.2-2018)推荐的估算模式AERSCREEN在气象和地形资料的处理以及建筑物下洗等多个方面做了改进。利用估算模式AERSCREEN,针对30 m左右高度的点源,进行了不同排放参数、不同气象条件下最大落地浓度的敏感性试验。结果表明:随着烟气出口流速的增大,地面浓度最大值逐渐减小;随着波文比的变化,地面浓度最大值没有明显的变化;随着地面粗糙度的增大,地面浓度最大值逐渐减小;随着烟气出口温度的增高,地面浓度最大值逐渐减小;当烟气温度为75℃,粗糙度达到1.3 m时,地面浓度达到最小;随着反照率的增大,地面浓度最大值逐渐减小;随着烟囱高度的增大,地面浓度最大值逐渐减小;在各种烟囱高度条件下,随着最高环境温度的增高,地面浓度最大值逐渐增大;而在各种环境温度条件下,随着烟囱高度的增高,地面浓度最大值在逐渐减小;模式中,随着最低环境温度的增高,地面浓度最大值没有变化;但随着最小风速的增大,模拟得到的地面浓度最大值会逐渐减小。

The AERSCREEN estimation model recommended in the"Guidelines for Environmental Impact Assessment of Atmospheric Environment"(HJ2.2-2018)had improved concerning the processing of meteorological and topographic data,as well as the downwash of buildings.The sensitivity test of maximum landing concentration under different emission parameters and meteorological conditions was carried out using the estimation model AERSCREEN,especially for the point sources at a height of 30 m.The results show that the maximum surface concentration decreases gradually with the increasing velocity of the flue gas outlet.The maximum surface concentration does not change obviously with the variation of the Bowen ratio.With the increased roughness of ground and temperature of flue gas outlet,the maximum ground concentration decreases gradually.When the temperature of flue gas is about 75℃and the roughness is 1.3 m,the surface concentration reaches the minimum.With increased albedo and chimney height,the maximum ground concentration decreases gradually.Under different chimney heights,the maximum ground concentration increases with the maximum ambient temperature.Under different ambient temperatures,the maximum ground concentration decreases with the increasing chimney height,which indicates that the increase of the maximum ambient temperature will reduce the maximum ground concentration.In this model,the maximum ground concentration does not change with the increase of the lowest ambient temperature.With the increased minimum wind speed,the maximum surface concentration obtained from the simulation will gradually decrease.