COMPUTATIONAL METHOD FOR THE METHYL AMINE H-2 GAS-MIXTURE CONCENTRATIONS IN METHYL AMINE/H2O/H, ABSORPTION-REFRIGERATION UNITS/

Substitution of ammonia by methyl amine is proposed in neutral gas abs orption refrigeration units using hydrogen as the pressure equalising gas. The throttling process of the conventional refrigeration units is being replaced by the diffusion of evaporated methyl amine through th e hydrogen atmosphere. Accurate knowledge of the thermophysical proper ties of the working fluids, as well as heat and mass transfer characte ristics, are required in the design of these units. This work reports an algorithm for the 'psychrometric problem', i.e. for the determinati on of the mass fraction of the methyl amine/hydrogen gas mixture from known 'dry' and 'wet' bulb temperatures. The values of the mixture's m ass fraction are computed for various combinations of 'dry' and 'wet' bulb temperatures, due to analytical correlations concerning the therm odynamic and transport properties presented by this paper. The final r esults are given in psychrometric charts for pressures from 17.5 bar t o 27.5 bar and temperatures between -30 and 50 degrees C. Copyright (C ) 1996 Elsevier Science Ltd