数值风洞与物理风洞对烟塔合一排烟的比较研究  

Comparative Study on Flue Gas Discharge by Natural Draft Cooling Tower with Flue Gas Injection between Numerical Wind Tunnel Mode and Physical Wind Tunnel

作　　者：张丽娜[1,2,3] 赵林[1] 陈璐[2,3] 马喆[2,3] 周阳 李志强[2,3] 

机构地区：[1]天津大学环境科学与工程学院,天津300072 [2]天津市环境保护科学研究院,天津300191 [3]天津市大气污染防治重点实验室,天津300191

出　　处：《环境科学与技术》2013年第5期141-146,共6页Environmental Science & Technology

摘　　要：热电厂"烟塔合一"排烟技术因其初期投资和运行维护费用少,排烟效果好、SO2落地浓度低等优势,特别是在机场附近的净空限高和对景观环境有特殊要求的地区具有广阔的发展空间。目前国内外广泛使用的大气污染物预测模型——德国模式在烟塔合一排烟方式的预测上尚存在许多问题,如大风下洗条件下,冷却塔附近空腔区的大小和范围、空腔区污染物最大地面浓度等难以给出准确的预测结果。为准确预测烟塔合一排烟方式的大气污染物扩散情况,一种新的大气污染物扩散预测模式——数值风洞模型以及物理风洞实验被用于模拟烟塔合一的环境影响,分析数值风洞模式和物理风洞实验在大气环境预测领域应用的适用性和优缺点。2个预测方法的结果表明:在烟塔合一排烟方式下,大气污染物最大落地浓度随风速增加而增加同时在冷却塔下风向存在负压区,污染物在该区域高浓度聚集。对2种方法进行比较,物理风洞实验由于受到物质和气象等条件的限制,无法得到精确的预测结果以及无法直观地描述空腔区的产生和变化规律。而数值风洞模拟具有更大的自由度和灵活性,预测出在夏季6 m/s风速下,冷却塔下风向最大落地浓度出现峰值,属于最不利的气象条件。同时该方法可利用图形化手段实现对空腔区产生、变化、破碎至再生成的全过程描述,从而建立了一种大气污染预测的重要手段。Natural draft cooling tower with flue gas injection in a burning coal plant has wide development space,especially in the area of near-the-airport limited height and special requirement landscape due to its advantages such as low height of cooling tower,small influence on the landscape,low initial investment,operation and maintenance cost,good effect of flue gas discharged from cooling tower and low ground SO2 concentration.Present widely used gas pollutant diffusion forecast mode-German mode has many key problems with prediction of flue gas discharge of natural draft cooling tower with flue gas injection,in case of gale downwash,it is difficult to predict accurately the size and area of negative pressure near the cooling tower and the maximum ground concentration in the cavity area.To accurately predict the flue gas pollutant diffusion by cooling tower,a new prediction mode-numerical wind tunnel mode and physical wind tunnel were used to forecast the influence of natural draft cooling tower with flue gas injection.The advantages and disadvantages of the two methods were analyzed in the application of atmospheric environment prediction.By natural draft cooling tower with flue gas injection,the maximum atmospheric pollutant ground concentration increased as the wind speed increased,and there was a cavity area where high concentration pollutant gathered at downwind of the cooling tower.Through the comparison of prediction results between the two methods,because of restrictions on meteorology and material conditions,physical wind tunnel cannot produce an accurate forecast conclusion and describe the generation and variety law of cavity area intuitively.Numerical wind tunnel mode has greater flexibility and freedom,it forecasts that when the wind speed was 6 m/s in summer,the maximum ground concentration at the downwind of cooling tower reached a peak,which was the most unfavorable meteorological condition in summer.The numerical wind tunnel mode can describe the entire process of the formation,change,breaking and ref

关 键 词：污染扩散 数值风洞 物理风洞 烟塔合一 预测模式 

分 类 号：X823[环境科学与工程—环境工程]