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ISSN Online: 2377-424X

ISBN Print: 0-85295-345-3

International Heat Transfer Conference 10
August, 14-18, 1994, Brighton, UK

HEAT AND MASS TRANSFER IN A TWO - PHASE FLOW OF A BINARY SOLUTION AND A GAS

Get access (open in a dialog) DOI: 10.1615/IHTC10.500
pages 299-304

Resumo

A numerical model of non-isothermal simultaneous mass and heat transfer between a gas and a binary solution in a diffuser was developed. The diffuser was taken as a conical profile, the gas phase as a continuous phase, and the liquid as a dispersed phase. The investigated solutions were polar, and the gas was partly absorbed by the liquid. This process was accompanied by a strong exothermal effect. The developed model was steady-state and based on unidimensional balance equations of mass, energy and momentum for the liquid and gas phases. Polynomial correlations were employed for thermodynamic properties. Momentum transfer by friction with the wall and gravitational and surface tension forces were not taken into account. The system of governing equations was transformed in matrix form and solved simultaneously. The numerical solution of the governing equations was obtained using Gear's method. The developed model permitted calculation of the behavior of the two-phase flow (gas and the dispersed liquid phase) as a function of the length of the diffuser. In particular , pressure, temperature and velocities of the gas phase and liquid drops and the concentration of the refrigerant in the solution as a function of the length of the diffuser were studied. The parametric studies also involved examination of the influence of the design parameters of the diffuser on the mass transfer process. Ways of augmenting the mass transfer process in the diffuser. are discussed. The calculations were performed for a mixture of refrigerant R134a (1 ,1,1,2-tetrafluoro-ethane) and an organic absorbent. This kind of diffuser has practical application as part of the mixer-preabsorber in refrigeration absorption systems.