基于SCREEN3的燃煤电厂海岸线熏烟问题研究

Research on shoreline fumigation of coal-fired power plant based on SCREEN3

以2×300MW、2×600MW、2×1000MW海边燃煤电厂为例,采用SCREEN3模式利用正交试验法研究了海岸线熏烟和常规气象条件下,不同烟囱高度、不同排烟温度、不同离岸距离时最大落地浓度及其发生距离。结果表明:对于海边大型燃煤电厂,海岸线熏烟的发生与离岸距离、烟囱高度、排烟温度等因素有关;海岸线熏烟最大落地浓度(Smax)是常规气象条件下最大落地浓度(Cmax)的2倍以上,有时甚至达到4倍以上。Smax和Cmax均随排烟温度的升高而降低,Smax随烟囱离岸距离的增加而升高;熏烟最大落地浓度的发生距离(SL)远大于常规气象条件下最大落地浓度的发生距离(CL),两者均随烟囱高度和排烟温度的升高而增加,SL随离岸距离的增加而缩短;对于离岸距离在3km以内的海边大型燃煤电厂,在环境影响评价时对厂址周边1.3～7.7km范围内有环境敏感点的区域要特别关注海岸线熏烟问题。

Taking 2×300MW,2×600MW and 2×1000MW units coastal coal-fired power plants as examples,based on SCREEN3 software,using the Orthogonal Experimental Method,the maximum ground-level concentration and its position are studied for different stack heights,different flue gas temperatures,and different offshore distances of stacks under shoreline fumigation and general meteorological conditions.The results show that shoreline fumigation is influenced by stack height,flue gas temperature and offshore distance of stack for large coal-fired power plant;the maximum ground-level concentrations in shoreline fumigation（Smax） are more than twice as high as that in general meteorological conditions（Cmax）,even some are over 4 times higher;both Smax and Cmax decrease with increasing the flue gas temperature,and Smax increase with increasing the offshore distance of stack;the distance from stack to the position where the Smax occur（SL） is more than that from stack to the position where the Cmax occur（CL）;both SL and CL increase with increasing the stack height and the flue gas temperature;SL decreases with increasing the offshore distance of stack;the shoreline fumigation should be paid particular attention for the large coal-fired power plants within 3km from the shore,especially when there are some environmentally sensitive areas within 1.3～7.7km radius around the plants.