New Working Medium-Absorbent System for Absorption Heat Pump

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This investigation was undertaken to examine whether the methanol-lithium bromidezinc chloride system is suited for absorption refrigerating machines, absorption heat pumps, and absorption heat transformers. The optimum mixing ratio of lithium bormide and zinc chloride was determined by measuring the crystallization temperatures of sample solutions. The most suitable mixing ratio of lithium bromide and zinc chloride was 1.0 weight and 1.0 weight, respectively. The thermal properties (heat capacity and heat of mixing ) and physical properties (density, viscosity, surface tension,solubility, and vapor pressure ) of the methnol-lithium bromide-zinc chloride system were measured. The measurements of density, viscosity, surface tension, vapor pressure, and heat capacity were carried out at various temperatures and absorbent concentrations. Solubilities were obtained in the range of temperatures from 265.85K to 343.35K. The heats of mixing at 298.15K were obtained for solutions whose absorbe … More nt concentrations range from 0 wt% to 65.8 wt%. The empirical formulas for solubility, vapor pressure, heat capacity, and heat of mixing were obtained from experimental data. On the basis of these observed data, the enthalpy-concentration chart of this three-component system was constructed.The theoretical analysis of the coefficient of performance was undertaken to examine the performance characteristics of this three-component system. The coefficient of performance for absorption refrigerating machines, absorption heat pumps, and absorption heat transformers were calculated using this enthalpy-concentration chart. The performance characteristics of this three-component system were compared with that of the water-lithium bromide system and that of the other systems using water , methanol, R22, and ammonia as the working medium. This three-component system was found to be suitable for an air-cooled single-stage absorption refrigerating machine, single-stage absorption heat pump, and single-stage absorption heat transformer. Less