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应用FLUENT商业软件,模拟水蒸气在水平管束外遇冷凝结的流动情况,数值模型基于多相流混合物模型,模型中加入自定义函数以实现蒸汽向水的转换,利用有限体积法及SIMPLE算法和标准的k-ε双方程求解控制方程组,得出换热器的表面传热系数,内部混合相压力、速度、温度的变化分布。模拟了管外径d=20 mm、排列方式分别为顺排和错排,在不同的横向间距S1以及不同的纵向间距S2下的换热情况。结果表明不论是顺排还是错排均在S1/d=1.4,S2/d=1.2下结果最优,在最优情况下错排构成的换热器表面传热系数比顺排高1.7倍,为设计高效冷凝换热器提供参考。
The FLUENT commercial software is used to simulate the flow of water vapor condensing outside the horizontal tube bundle. The numerical model is based on the multiphase flow mixture model. The model incorporates a custom function to convert steam to water. The finite volume method and the SIMPLE algorithm and standard K-ε two equations to solve the control equations, the heat exchanger surface heat transfer coefficient, the internal mixed phase pressure, velocity and temperature changes in the distribution. The tube outside diameter d = 20 mm is simulated. The arrangement is the heat exchange in the row and the row, respectively, at different transverse distances S1 and different longitudinal distances S2. The results show that the results are the best under both S1 / d = 1.4 and S2 / d = 1.2. The heat transfer coefficient of the heat exchangers formed by the misplaced heat exchangers is 1.7 times higher than that of the parallel ones, Provide reference for designing efficient condensing heat exchanger.