Exergy analysis of freeze concentration unit
The technique of energy-exergy analysis of the technological system for concentration of liquid food and biotechnology environments by cyclic freezing of moisture is presented. Functional dependencies allowing controlling the quality of energy potential that could be transformed into useful work are shown. On the basis of working regime parameters for freeze unit, built-in refrigeration unit, and external flows of energy the thermodynamic analysis of this energy-technological system is performed. The calculations and visual interpretation of the exergy balance in the form of Grassmann-Shargut charts’ flow and exergy loss are shown to allow qualitative evaluating the full range of exergy losses in the elements of freeze concentration unit of cycle operation due to both reversible and irreversible processes of heat- and mass transfer. It was found that the process of concentration is implemented effectively when exergetic performance coefficient of the unit equals to 23.4%, and the greatest losses of exergy are observed in the expansion valve and the condenser of the refrigeration unit due to internal exergy losses caused by phase transformations of the refrigerant.