干式冷却塔冬季防冻的应用分析

摘要

A mathematical model is presented to predict the condensing and frost formation characteristics on the heat transfer surfaces by simultaneously considering the condensing and frost layer. The model employs one-dimensional transient formulation based upon the local averaging technique, taking into account the variation of the frost density and thickness. The presented model is validated by comparing with the experimental data provided by the dry cooling tower manufacturer. It is found that, the model can predict the heat transfer performance of the dry cooling tower with accuracy within 2.19%. Dry cooling tower heat transfer performance at different air and water flow rates are predicted when it operates with water as heat transfer fluid during the winter period. The mathematical model and research results are helpful to the operation of such kind of dry cooling tower with water as the coolant during the winter period.%本文通过同时考虑冷凝和结霜层提出了一个能预测换热表面冷凝和结霜特性的数值模型。该模型采用基于局部平均的一维瞬态的数值方法，同时考虑了霜层密度和厚度的变化。该模型通过干式冷却塔制造商提供的实验数据来进行验证。模拟结果表明，该模型能有效预测干式冷却塔的传热性能，其精度在2.19%的范围内。同时计算了在冬季以水为传热工质情况下，不同空气和水流速的干式冷却塔的传热性能。本文的数值模型和研究结果将有助于以水为传热工质的干式冷却塔在冬季的运营和操作。