Exergy Analysis of Vapour and Sorption Cooling Processes

Exergy is precious energy. On the basis of thermodynamic analysis of thermal processes, one can choose more exergy-saving devices. This is especially important in refrigeration processes, in which the consumption of energy and exergy increases considerably with the falling cooling temperature. The exergy efficiency in terms of exergy losses of vapour compression and sorption cooling processes is analysed in the paper. In the case of vapour compression processes, analysis of the influence parameters on exergy efficiency shows a strong dependence on the cooling temperature. Exergy efficiency of sorption processes depends mainly on cooling and regeneration temperature. A comparison of exergy efficiencies of vapour compression and sorption cycles has been made for average values of working parameters. B anergy (J) E exergy (J) Q heat quantity (J) T temperature (K) Indexes a -actual am -ambient ave actual, vapor compression as actual, sorption Ca -Camet's exvc exergetic, vapor compression exs exergetic, sorption h -heating NOMENCLATURE t temperature CC) Wenergy (J) '11 efficiency (-) ha hr lvc Is R s vc heating, actual heating, reversible losses, vapor compression losses, sorption refrigeration -sorption vapor compressiOn