转角正方形管束有降膜流动时的压降实验

Experimental Study on Pressure Drop of Falling Film Flow Across Tube Bundles in Rotated Square Arrangement

为了深入研究大型海水淡化装置中流动阻力对装置性能的影响,建立了大型水平管束降膜流动特性实验台,模拟了水平管降膜蒸发器内蒸汽的流动过程,分析了饱和蒸汽温度和喷淋密度对管束流动阻力的影响.引入新的参数(喷淋雷诺数)对实验数据进行了拟合,得出蒸汽横掠有降膜流动的转角正方形管束的压降系数公式.结果表明:在相同的蒸汽质量流量和喷淋密度下,压降随饱和蒸汽温度的升高而降低;压差预测值与实验值的误差小于±15%.

To study the effects of flow resistance in large-scale seawater desalination facility on the performance itself, an experimental setup was built to simulate the steam flow process in a horizontal-tube falling film evaporator, so as to analyze the influence of saturated steam temperature and spray density on the flow resistance in the tube bundle. The new parameter （Reynolds number of spray water） was used to fit the experimental results, and subsequently a pressure drop coefficient formula was obtained for the steam flow across the tube bundle in rotated square arrangement. Results show that for a constant steam flow and spray density, the pressure drop reduces with rising saturated steam temperature, and the error of differential pressure is within ±15% between predicted value and actual measurement.