采用数值风洞模型对热电厂烟塔合一大气污染扩散的研究  

Study on the diffusing of flue gas pollutant from natural draft cooling tower with flue gas injection using numerical wind tunnel mode

作　　者：张丽娜[1,2,3] 马喆[2,3] 周阳 李志强[2,3] 陈璐[2,3] 王红宇[2,3] 杨志斌[4] 

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 [4]天津大学机械工程学院,天津300072

出　　处：《环境污染与防治》2013年第4期67-74,80,共9页Environmental Pollution & Control

摘　　要：随着城市的快速建设,城市建筑的高度和体量不断增加,同时大气污染源的排放方式和排放状态也与从前发生了很大的变化,特别是热电厂采用烟塔合一排放方式的出现,对常规应用的稳态远距离以统计学为基础理论的高斯大气预测方法提出了挑战。目前国内外广泛使用的大气污染物预测模式——德国模式在烟塔合一排放方式的预测上存在着许多关键性问题,如大风下洗条件下,冷却塔附近空腔区的大小和范围、空腔区污染物最高地面浓度等无法给出准确的预测结果。为准确预测烟塔合一排放方式的大气污染物扩散情况,采用一种新的大气污染物扩散的预测模式——数值风洞模型进行模拟预测研究,预测结果表明,在烟塔合一排放方式下,大气污染物最高地面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。且在夏季6.0m/s风速下,冷却塔下风向最高地面浓度出现峰值,属于最不利的气象条件。数值风洞模型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。With the rapid development of the urban construction, the height and area of the buildings are increasing constantly. At the same time, the discharging mode and state of the atmospheric pollution sources have also experienced fundamental changes, which challenge the regular stable long-distance forecast method of gauss atmospheric pollution based on statistical theories. At present the gas pollution forecast mode （the German mode）, which is widely applied in China and abroad now about the prediction of the gas discharging mode of natural draft cooling tower with flue gas injection has many key problems, for example, in case of gale downwash, it is difficult to predict accurately the size and area of the cavity near the cooling tower and the maximum ground level pollutant concentration in the cavity. In order to accurately predict the diffusing flue gas pollutant by natural draft cooling tower with flue gas injection, the study on simulation and prediction of diffusing flue gas pollutant, which used a new prediction mode-the numerical wind tunnel mode had carried out. The forecasting results show that by natural draft cooling tower with flue gas injection, the maximum atmospheric pollutant ground concentration should increase as the wind speed increased, and there was a cavity area where the high-concentration pollutant gathered at downwind of the cooling tower. At the same time when the wind speed is 6.0 m/s in summer, the maximum ground concentration at the downwind of the cooling tower reached a peak, it is the most unfavorable meteorological condition in summer. The numerical wind tunnel mode can describe the entire process of the formation, change, breaking and re-formation of the cavity area in a graphical way. It provides a new important method for the forecast of atmospheric pollutant.

关 键 词：污染扩散 数值风洞 烟塔合一 环境影响 

分 类 号：X773[环境科学与工程—环境工程]