Evaluation of heat and mass transfer coefficients in horizontal tube falling film NH3-H2O absorber

Abstract

Absorption phenomenon of NH3 into NH3-H2O solution has analysed theoreticcally. The heat transfer coefficient obtained from the coupled heat and mass transfer mathematic model. This heat transfer coefficient is used to calculate the variation of the simulated value of heat load. The practical decrease of wetted ratio analyses were taken into account when the solution flow from the top to the bottom of the parallel tube bundle. The deviation of theoretical heat load and experimental heat load is about 10%. In addition heat transfer coefficient and mass transfer coefficient of the absorption process are agree well with other studies. A correlation which gives the heat transfer coefficient and mass transfer coefficient as funtions of the initial solution concentration, solution mass flow rate per unit tube length, and cooling water temperature are derived to estimate the absorber heat load and mass absorption flow rate of NH3 vapor into NH3-H2O solution.