Transient analysis of the steam-water direct contact condensation in the packed column

摘要

The transient heat transfer behaviour of direct contact condensation of steam in spray cooling water in a packed column was investigated experimentally and theoretically in this work for the first time. A new analysis method of the state equation was applied to analyze the molar quantity variation of steam in the course of the experiment. The results showed that increasing the cooling water flow rate properly could significantly accelerate the steam condensation rate and this was more obvious at the beginning of the operation. The higher the flow rate of the cooling water was, the shorter a time it took for the steam to be completely condensed. When the cooling water flow rate was 840 L/h, the steam was mainly condensed within 13s, which indicated that it would rapidly handle steam by regulating cooling water flow rate. However, the effect of changing cooling water temperature on steam condensation rate is slight with the cooling water temperature inceasing from 23 degrees C to 42 degrees C. The volumetric heat transfer coefficient in this experiment is in the range of 1.47kWm(-3)K(-1) to 10.93kWm(-3)K(-1) with the cooling water flow rate inceasing from 120L/h to 840L/h, and the maximum uncertainty in the results is 2.2%.