Improved Heat Transfer Performance of Falling Film Evaporator for Desalination Industry by Balanced Liquid Distribution

Abstract

Horizontal-tube falling film evaporators (HFE) are widely used in the thermal desalination industry due to their increasing advantages. The liquid distribution state of the tube bundle directly affects the heat transfer performance of the evaporator. To improve the uneven liquid distribution among tube rows, a balanced distribution structure (BDS) that can balance the liquid distribution state in the HFE was proposed. A general distributed parameter model was built to describe the steady-state performance of the HFE with and without the BDS, taking into account different liquid distribution of odd and even rows. The model is applied to simulate the multieffect distillation (MED) system of a desalination power plant, and the numerical results show a good arrangement with the operating results. The results indicate that the BDS slightly improves the overall heat transfer performance and the total evaporation rate. This work and the designed BDS certainly could help in the design and optimization of HFE for desalination processes.

Effect of Structural Optimization of Scrubbing Cooling Rings on Vertical Falling Film Flow Characteristics

“…thermal energy engineering, mechanical engineering, and engineering thermo-physics and nuclear energy fields due to its excellent properties, such as the small flow rate, small temperature difference, simple structure, high heat-and masstransfer coefficient, and low power consumption. Nowadays, the falling film evaporator, 7 air conditioning refrigerator, 8 horizontal falling film exchanger (HFFE), 9−11 and condenser 12 have been widely used in various heat exchange systems. The falling liquid film can be divided into three regions as the distance increases during the flow process, including the entrance region, the development region, and the stable region.…”

“…Such falling film flow has been widely used in various chemical engineering, thermal energy engineering, mechanical engineering, and engineering thermo-physics and nuclear energy fields due to its excellent properties, such as the small flow rate, small temperature difference, simple structure, high heat- and mass-transfer coefficient, and low power consumption. Nowadays, the falling film evaporator, air conditioning refrigerator, horizontal falling film exchanger (HFFE), − and condenser have been widely used in various heat exchange systems.…”