Determination of operating temperature in main generator of a two-stage absorption refrigeration machine working on an aqueous solution of lithium bromide

Abstract

This paper examines the thermal characteristics of a two-stage absorption refrigeration machine. When carrying out a numerical analysis, it turned out that the secondary generator’s temperature was not constant, and it was also found that the coefficient of thermal performance of this cycle increased significantly at the beginning, then stabilized at a certain value for the temperature degree of the primary generator. But this result is not the right value for calculating the absorption refrigeration cycle; it might cause crystallization inside the cycle and This was verified based on the thermodynamic relationship chart (h-X-T) for LiBr-water solution. In addition, the decisive point for determining the appropriate temperature is to study the change in refrigeration capacity in the process when the temperature of the generator changes. In this case, the design temperature for the primary generator should be in the range between the temperature corresponding to the highest refrigeration capacity and the temperature far from the crystallization phenomenon.