Research on film condensation heat transfer of the shell side of the spiral coil heat exchanger

摘要

The theoretical basis for the calculation of shell side condensation of the spiral coil heat exchanger is weak. In order to solve the problem of pure steam film condensation heat transfer of the shell side of the spiral coil heat exchanger, the theoretical model of the homogeneous flow was established. Considering the centrifugal force, two different mathematical models were established and the heat transfer characteristics were studied. The solution formula of the heat transfer coefficient and thickness of first layer liquid film, meanwhile, was obtained. The theoretical formula of the membrane-like condensation heat transfer of the heat exchanger was worked out, based on the calculation model of the heat transfer coefficient of one-component working fluid outside the tube bundle, considering the effect of tube bundle. The two calculated results in this paper and the theoretical result of Bays and McAdams were compared with experimental values respectively. The results show that the relative error between the calculated values obtained by the two theoretical models and experimental values is 7.48% (ignoring centrifugal force), 3.05% (considering centrifugal force), while the relative error between Bays and McAdams’s result and the experimental value is 61.3%. The correctness of the theoretical models proposed in this paper are verified. The theoretical models can be used to calculate the film condensation heat transfer of the spiral coil heat exchanger.