Experimental Investigation Of Heat Transfer Performance Of The Umbrella-Plate Falling Film Evaporator

The heat transfer performance of the umbrella-plate falling film evaporator was studied, water and concentration of 5%-40% potash was used as medium in this paper. At first, by theoretically analyzing the instance of heat transfer on the umbrella-plate evaporator. The formula of the heat transfer coefficient on the evaporation side in the umbrella-plate could be obtained. The influence of difference in temperature, Reynolds number of film and Prandtl number to the heat transfer performance on the evaporation side was discussed via the uniform wall temperature experiments. By analyzing above influence factors, The character of umbrella-plate evaporator which is fit for evaporation under little difference in temperature and fit for evaporating heat sensitivity materiel could be obtained. The experimental correlation formula of the heat transfer coefficient on the evaporation side in the umbrella-plate was obtained. The predicated heat transfer coefficient through the formula was finely accord with the experimental result, and the error was basically under 10%.By theoretical analysis and experimental investigation to the exasperate position of the heat transfer in the umbrella-plate falling film evaporator, The exasperate experimental formula of the heat transfer was obtained. With the same Reynolds, The high-point heat flux density of umbrella-plate evaporator is higher than vertical-plate evaporator could be observed from above formula, which maked out that with little Reynolds liquid film was not easy to break.