Hydrodynamic And Heat Transfer Performance In Novel Direct Contact Condenser

In this thesis, a novel direct contact condenser with SV /SK-static mixer was developed. A sintered powder airblasthead was used as the gas distributor. The hydrodynamic performance of the two novel condensers was firstly tested in air-water system, as it is convenient to observe without insulating layer. The size of bubbles, gas hold up, pressure drop and velocity vector distribution were tested during the first section. Based on the former experiment, the heat transfer performance of the two novel direct contact condensers were studied in steam-water system. The heat transfer efficiency, temperature axial distribution, volumetric heat transfer coefficient and critical liquid flow rate were tested in this section. Regarding to its meaningful application in LNG Terminal, we choose nitrogen-liquid nitrogen substitute for nature gas which could be dangerous and pollutional. The heat transfer performance of the novel direct condenser was tested in the low temperature system. This work will provide valuable reference for industrial application.The experimental results show that the vapor bubbles size of the novel direct contact condenser with SV-static mixer is more uniform than that of the direct contact with SK-static mixer; the heat transfer efficiency and volumetric heat transfer coefficient in the SV-static mixer is larger than that in the SK-static mixer; however,the novel direct contact condenser with SV-static mixer has a higher pressure drop and a larger two-phase flow resistance than that with SK-static mixer. Moreover,the application of airblast head in such condensers can effectively improve the heat transfer efficiency and reduce the noise and vibration caused by the condensation of steam.