间接空冷机组空冷塔塔群内空气流动及传热性能研究

由于具有巨大的节水优势,间接空冷机组在我国富煤少水区域得到广泛应用。研究环境风对间接空冷系统的影响机理对指导电厂运行具有重要意义。以某电厂间接空冷机组为基础,构建水平布置散热器的空冷塔群物理和数学模型,通过数值模拟方法分析环境风对塔内空气流场及空冷散热器换热性能的影响。结果表明:环境风对空冷系统塔内空气流场影响较大,进而影响空冷散热器的散热性能。随着风速的增加,空冷塔的换热性能不断恶化。在临界风速时额定负荷下,下游空冷塔换热量比上游空冷塔减少2.5%。

Study of the Air Flow and Heat Transfer Performance Inside an Air Cooling Tower Group of an Indirect Air Cooling Unit

Due to a huge water saving advantage, the indirect air cooling units get a wide use in the regions where are rich in coal and short in water. It is of a major importance to investigate the mechanism governing the influence of the environment wind on an indirect air cooling system to guide the operation of the whole power plant. With an indirect air cooling unit in a power plant serving as an example, established were a physical and mathematical model for air cooling tower groups of which the heat radiators were horizontally arranged. Through employing the numerical simulation methods, the influence of the environment wind on the air flow field inside the towers and the heat exchange performance of the air cooling radiators was analyzed and a quantitative analytic result was obtained. It has been found that the environment wind exercises a big influence on the air flow field inside the towers of the air cooling system and further has an influence on the heat radiation performance of the air cooling heat radiators. With an increase of the air speed, the heat exchange performance of the air cooling towers will get worsened continuously.At the critical wind speed, the amount of heat exchanged at the rated load in the downstream air cooling tower will decrease by 2.5% compared with that in the upstream air cooling tower.