Cogeneration means the simultaneous generation of different forms of energy from fossile fuels: Energy as high grade mechanical/electrical energy and thermal energy for different modes of application. An interesting possibility to use thermal energy of low or medium quality is the conversion to refrigeration by means of absorption refrigeration systems.
Absorption refrigeration was invented even earlier than mechanical refrigeration; for many years it was considered inferior. Process improvements and the increased attention to energy conservation and waste heat utilization in the last years, however, made this system attractive again as promising alternative to mechanical vapor compression.
The advantages of this system become particularly evident for low temperature applications. More than 50% of the plants built in the last 20 years by the leading manufacturer in this field are designed for evaporation temperatures below −40° F, most of them in freeze-drying plants with temperatures down to −65° F, where they have been proven under severe working conditions with very sensitive products.
In the citrus industry the greatest amount of refrigeration is required for concentrate processing at a temperature level of approximatley −41° F. And this is the reason why ammonia absorption refrigeration systems — particularly integrated in cogeneration plants — should be of interest for the citrus industry. Therefore absorption refrigeration will be a focal point of this paper.
Paper published with permission.
