Experimental study on the heat and mass transfer characteristics of air-water two-phase flow in an evaporative condenser with a horizontal elliptical tube bundle

摘要

In this paper, the heat and mass transfer performance of an evaporative condenser with a horizontal elliptical tube bundle was experimentally studied. The effects of important parameters, such as the spray density, frontal air velocity, ambient temperature and humidity, on the heat and mass transfer performance were discussed in detail. Among all parameters studied, it was found that the wet bulb temperature has greater effects on the heat transfer performance than the relative humidity. The difference between the steam temperature and tube wall temperature, the inlet steam flow rate and the steam saturation temperature all affect the mean within-tube condensation heat transfer coefficient. The mean within-tube condensation heat transfer coefficient increases greatly when the latter two increase, while the increase in the difference between steam and tube wall temperature hinders the mean within-tube condensation heat transfer coefficient. The empirical correlations of the mean within-tube condensation heat transfer coefficient, wall-film convective heat transfer coefficient and the film-air convective mass transfer coefficient were finally obtained by regression fitting the experimental data using the least square method and all empirical correlations have enough precision in engineering calculation.