Performance study of a solar absorption power-cooling system

A combined power and cooling cycle can be driven by low grade solar heat to service power and cooling demands in buildings. By operating this cycle to match the building demands, the overall annual performance is improved. In the present study, the annual performance of a solar driven ammonia-water absorption power and cooling system with a biomass auxiliary was investigated for Seville, Spain, and Chennai, India. A scroll expander was considered for the generation of power. The solar water heating system comprises an area of 450 m2 south facing evacuated tube collectors inclined at 37° and 13° (Seville and Chennai respectively) and a buffer tank volume of 18 m3. The effect of heat source temperature, cooling water inlet temperature and the chilled fluid inlet temperature on the cycle has been studied. The monthly energy based performance of the system operating between 6.00 and 18.00 hours for the two locations was also evaluated. The yearly efficiency of the scroll expander is between 59% and 63%, whereas the annual system efficiency varies in the range of 6-8%, while the annual solar contribution changes between 23% and 30% depending on the location of the system and evaporator temperature.