Performance assessment of a solar powered ammonia-water absorption refrigeration system with storage units

Solar thermal energy is one of the viable options for space cooling in the quest of greener environment and energy efficiency. The major challenge in actualizing the use of solar energy to drive cooling systems such as absorption chillers is its intermittent nature, thereby not able to cover significantly the period of cooling demand in most situations. In order to achieve continuous cooling energy supply from solar driven absorption chillers, the present study considered two alternative storage units in the form of chilled water and ice, integrated to the main chiller installed in Dhahran, Saudi Arabia. The system is designed to allow different operational modes in accordance with the cooling demands. The system is tested experimentally where the storage units are used alternatively and the results are presented. A mean chiller COP for cooling the space and chilling the water was found to be 0.8 whereas it was 1.3 for only making ice. Maximum COP (0.8) was found at Tgen = 120 °C at an average condenser and evaporator temperatures of 34.5 °C and −2.2 °C, respectively.