Experimental study of heat transfer and scale formation of spiral grooved tube in the falling film distilled desalination

Abstract

The heat transfer performance and scale formation of spiral-grooved tube in the falling film evaporator was studied experimentally compared with the conventional smooth tube. A series of experiments were performed contrastively on the two types of heat transfer tube based on a heat exchange test platform of horizontal tube falling film evaporation for desalination. The influences of various factors on heat transfer coefficients for the spiral-grooved and smooth tubes were investigated. Heat transfer experiments indicated that the heat transfer coefficient of the spiral-grooved tube can be improved by approximately 35%, comparing with the smooth tube under the same experimental conditions. The anti-scaling capability of spiral grooved tube is a little better than that of smooth tube. Their scaling layers had similar thickness under the same operation condition, and their cohesiveness with the tube was weak. Experimental findings indicated that the spiral-grooved tube was feasible for application in seawater desalination given the enhancement of heat transfer and anti-scaling characteristics.