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Abstract: Various researchers have developed models of conventional H2O–LiBr absorption machines with the aim of predicting their performance. In this paper, the methodology of characteristic equations developed by is applied. This model is able to represent the capacity of single effect absorption chillers and heat pumps by means of simple algebraic equations. An extended characteristic equation based on a characteristic temperature difference has been obtained, considering the facility features. As a result, it is concluded that for adiabatic absorbers a subcooling temperature must be specified. The effect of evaporator overflow has been characterized. Its influence on cooling capacity has been included in the extended characteristic equation. Taking into account the particular design and operation features, a good agreement between experimental performance data and those obtained through the extended characteristic equation has been achieved at off-design operation. This allows its use for simulation and control purposes. [Copyright &y& Elsevier]

Abstract: A facility for experimental evaluation of innovative components forming part of a single effect LiBr–H2O adiabatic absorption chiller is described. Plate heat exchangers have been incorporated in the design. Two adiabatic absorber configurations, droplets and liquid sheets, were designed and tested and its performances parameters were experimentally determined. Evaporator limitations have been identified and included in the analysis. Liquid accumulation leads to overflow of refrigerant out of the evaporators. Some general observations, regarding particular operating conditions, are reported. The absorber performance has been characterized in terms of heat and mass transfer through the heat conductance and the effectiveness. The influence of the recirculation ratio is presented for both cases. The liquid sheet configuration has shown better evaluation parameters than droplets configuration. A significant reduction in the absorber size (up to 50%) as compared to using droplets is possible. [Copyright &y& Elsevier]