Heat and mass transfer enhancement for falling film absorption with coated distribution tubes at high temperature

• The experiment of circumferential coated tubes at high temperature is conducted.
• The higher heat transfer coefficients of falling film absorption are gained.
• The mass transfer coefficient of the circumferential coated tube is lower.

This paper experimentally studied the characteristics of the vertically falling film absorption outside a brass tube with different circumferential coating patterns at high temperature. The effects of spraying liquid density and inlet temperature of solution on heat and mass transfer are investigated. The results show that the heat transfer coefficient of falling film absorption increases with the increase in the spraying liquid density of solution; the mass transfer coefficient of falling film absorption increases initially, and then decreases with the increase in spraying liquid density of solution. The heat and mass transfer coefficients of falling film absorption increase with the increase in the inlet temperature of LiBr solution and the operation temperature. With the same spraying liquid density and the inlet temperature of LiBr solution, the overall heat transfer coefficient of the circumferential coated division tube is higher than that of the bare brass tube; however, the mass transfer coefficient of the circumferentially coated division tube is lower than that of the bare brass tube.