The falling film flow has attracted much attention recently due to its advantages of low temperature difference, low flow rate, high heat transfer coefficient and high heat flux density. In this paper, a series of experiments were carried out to investigate the falling film flow and heat transfer characteristics outside the vertical tube based on the established experimental system. Flow patterns, the trend of heat transfer coefficients along the tube as well as the falling film breakdown phenomenon were described. Two new correlations were obtained to predict the heat transfer coefficient and falling film dry burning based on experimental data, and the maximum deviation between the experimental data and predicted values were -13.36% and 16.81%, respectively. The new correlations can provide a reference for the design of the heater in the Mechanical vapor recompression systems.

降膜流动由于具有温差小、流速低、传热系数高、热流密度高等优点，近年来备受关注。本文在建立的实验系统的基础上,开展了一系列实验,研究了垂直管外降膜流动和传热特性。描述了流动模式、沿管传热系数的趋势以及降膜击穿现象。根据实验数据获得了两个新的相关性来预测传热系数和降膜干烧，实验数据与预测值的最大偏差分别为-13.36%和16.81%。