Modeling of conjugated heat and mass transfer in the entrance region of falling liquid film at various values of the Froude number

Maria V Bartashevich

doi:10.1051/matecconf/201819401007

Abstract

Mathematical model of conjugated heat and mass transfer in absorption on the entrance region of the semi-infinite liquid film of lithium bromide water solution is investigated for different values of Froude number. The calculations shown that larger values of Froude number corresponds to a smaller thickness of the falling film. It was demonstrated that for large values of the Froude number the heat transfer from the surface is greater than for smaller values.

Highlights

In absorption chillers and in the spray-type devices the heat and mass transfer processes take place and proceed with a pressure-driven liquid film flow through holes or slits
In other types of devices, including film-like devices, such flows are possible at the exit of the distributors
The liquid flow with a free boundaries in the real devices are often conjugated by the various heat and mass transfer processes such as absorption

Summary

Problem statement

In absorption chillers and in the spray-type devices the heat and mass transfer processes take place and proceed with a pressure-driven liquid film flow through holes or slits. The liquid flow with a free boundaries in the real devices are often conjugated by the various heat and mass transfer processes such as absorption. The solutions for simple problems of the coupled heat and mass transfer during absorption at the liquid/gas interfaces of different geometry types (films, jets, drops, sheets) are given in [1, 2]. Where L D / (1 Ci ) , L is latent heat of phase transformation, J/kg; is solution density, kg/m3; is heat conductivity, W/(mK) This equilibrium condition joins equilibrium temperature Td with concentration Cd. We assume the asymptotic boundary condition at y :

Calculations

Conclusions