Numerical simulation of non-isothermal absorption in a liquid film moving over a cooled horizontal surface under the action of a gas flow

Maria V Bartashevich,G.V Kuznetsov,D Feoktistov,E Bulba

doi:10.1051/matecconf/201819401008

Abstract

Mathematical model of absorption on a horizontal film of lithium bromide water solution flowing on a cooled wall under the action of shear stress is numerically investigated in this paper. The shear stress on the film surface is set by the motion of co-current or counter-current surrounding saturated water vapor flow. It is known that the external shear stress is caused by the motion of surrounding saturated water vapor intensificate the process of non-isothermal absorption in comparison with the fixed-vapor regime. Our calculations have shown that at low values of heat flux the film temperature and vapor concentration in the solution downstream increases due to absorption.

Highlights

Mathematical model of absorption on a horizontal film of lithium bromide water solution flowing on a cooled wall under the action of shear stress is numerically investigated in this paper
The necessity of heat and mass transfer intensification in the absorption chillers is caused by the limitations towards their size and consumption of materials
The investigation of thin liquid film flowing down a vertical wall in the roll-wave regime in presence of heat and mass transfer through the free surface was presented in [4,5]

Summary

Problem statement

The necessity of heat and mass transfer intensification in the absorption chillers is caused by the limitations towards their size and consumption of materials. Our numerical modelling of the conjugated heat and mass transfer in absorption chillers focuses on the film flow process on cooling wall. The investigation of thin liquid film flowing down a vertical wall in the roll-wave regime in presence of heat and mass transfer through the free surface was presented in [4,5]. The analytical solution to the problem of conjugate heat and mass transfer in a laminar falling liquid film with a linear velocity profile is presented in [7]. That the lithium bromide–water solution liquid film flowing under the action of the external tangential stress on the film surface. It is assumed that the shear stress applied to the interface will allow intensification of the process of non-isothermal absorption in comparison with the fixed-vapor regime.

Numerical calculations

Conclusions