Abstract:

In the fields of electric power, metallurgy, chemical industry and other industries, circulating cooling water is an indispensable and important process, in which open cooling tower is the most widely used form at present. However, the large evaporation loss of open cooling tower makes the circulating cooling water process one of the key water consumption units in industry. With the increasingly severe situation of national water resources, the water-saving requirements are becoming more and more strict, therefore, closed air cooler has been widely concerned and developed because of its advantages of water saving and high efficiency. The closed air coolers currently used were divided into three categories: dry type, wet type and dry wet combination. The structure, principle and performance characteristics of the latter two types of air coolers were emphatically analyzed. It was proposed that the evaporative air cooler greatly improved the heat exchange efficiency by making full use of the phase change latent heat of water, and had the most development potential. Through the selection of base tube shape suitable for water film forming, increasing the water film heat exchange and using hydrophilic coating to maximize water film evaporation heat transfer, meanwhile, control the evaporation scaling is an important development direction to further improve the heat transfer capacity and stability of air cooler in the future.

Key words: air cooler, circulating cooling water, water film evaporation, scaling

摘要：

在电力、冶金、化工等工业领域，循环冷却水系统是不可或缺的重要系统，开放式凉水塔是目前应用最多的冷却器形式，但其蒸发损失较大，使得循环冷却水系统成为工业领域重点耗水单元之一。随着国家水资源形势愈加严峻，节水要求愈加严格，密闭式空气冷却器以其节水、高效等优点，逐渐受到广泛的关注和开发。将目前应用的密闭式空冷器分为了干式、湿式和干湿联合三大类，并重点分析了后两类空冷器的结构、原理和性能特点，提出蒸发型空冷器通过充分利用水的相变潜热，大幅提高了换热效率，最具有开发潜力，通过适合水膜成形的基管形状选择，增大水膜换热面积，采用亲水涂层等方式最大化强化水膜蒸发传热，并控制蒸发结垢，是未来进一步提高空冷器传热能力和换热稳定性的重要开发方向。

关键词: 空冷器, 循环冷却水, 水膜蒸发, 结垢

CLC Number: 

• TQ085