The Study Of Heat Transfer Performance Of Aluminium-Carbon Steel Composite Tube Film Evaporator

Film evaporator is widely applied in various industrial fields. Due to the long-term influence of spray water, the heat transfer tube is easy to corrode, which increases the cost of equipment. This paper innovatively cover aluminum on the surface of carbon steel through special process so as to form aluminum-carbon steel composite tube, which has a strong capability of resistant to corrosion with no apparent cost increasing.However, the thermal contact resistance caused by the gap between aluminum layer and the carbon-steel layer may lead to the increase of total thermal resistance, then affect the overall heat transfer performance of heat exchanger tube. This paper makes a systematic study on the heat transfer performance of the composite film evaporator in order to lay a good theoretical basis for the large-scale promotion and application of it.This paper makes a comparision for the heat transfer performance between two kinds of tubes in the heat exchanger in order to systematically assess the feasibility of applying aluminum-carbon steel tube to replace the carbon steel tube in film evaporator under the certain range of conditions of head-on wind and spray water. Experiments show that:the total heat transfer coefficient of aluminum-carbon steel composite tube is5.98%lower than that of carbon steel and the total thermal resistance of composite tube is26.4%higher than that of carbon steel which are feasible in industrial fields.Applying aluminum-carbon steel composite tube in the film evaporator experimental platform to acquire total heat transfer coefficient and water film heat transfer coeffient though experimental data and calculation under the effect of change of velocity of head-on wind and the density of spray water. The related heat transfer connection equation shows that the velocity of gead-on wind is the main factor and the density of spay water is less important during the whole process of heat transfer.