Calculation of Flow Field and Vibration Analysis of Heat Exchanging Tube in Low Temperature Multi-effect Seawater Desalination Evaporator

Abstract In this paper, a 1000t/d low-temperature multi-effect seawater desalination pilot plant (MED) is taken as the research object, a multi-phase flow (VOF) model is selected to describe the shell side flow field of the evaporator, and the overall direct simulation of the flow field on the shell side of MED is carried out by using the fluid mechanics calculation software Fluent. The vapor velocity field distribution around the evaporator tube bundle is obtained by calculation under stable test conditions. The influence of seawater spray density and evaporation temperature on flow field distribution and the vibration of tube bundle under different working conditions are researched. Research result shows that the spray density has little effect on steam velocity, but the maximum steam velocity is significantly affected by evaporation capacity of seawater. At the same time, when the evaporation capacity reaches a certain value, the phenomenon of flow resonance will occur in some areas of the evaporator, which will cause damage to the heat exchange tube bundle.