Numerical Simulation on Heat Transfer Characteristics of Plate and Tube Falling Film Evaporator
The falling film evaporator has the characteristics of higher heat transfer efficiency of flooded evaporator and smaller refrigerant filling capacity of the dry-type evaporator.This article conducts numerical simulation on the plate tube falling film evaporator and obtains the effects of slot width,spray density and plate surface temperature on the heat transfer performance of the evaporator when R410A is used as the refrigerant.The results show that when the width of the working fluid inlet slit is 1.5mm,the liquid film coverage and heat transfer coefficient on the board surface are the highest.When the slit width is less than or greater than 1.5mm,the liquid film coverage and heat transfer coefficient on the board surface are both reduced;The liquid film coverage and heat transfer coefficient of the plate surface increase with the increase of the liquid film Reynolds number,but when the liquid film Reynolds number reaches over 10000,the increase amplitude significantly decreases and tends to zero;The increase in plate temperature can enhance the heat transfer performance of the evaporator,but the effect is very small at low Reynolds number.Only when the Reynolds number is large enough the influence of plate temperature can be reflected significantly.
falling film evaporatorheat transfernumerical simulationtwo phase flowflow
万方数据
维普
