Effect of storage tanks on solar-powered absorption chiller cooling system performance

Abstract

Thermal storage, low power tariff at night, and low nocturnal temperature can be used in synergy to reduce the cooling costs of the solar-powered absorption chiller cooling systems. This study aims to reduce the required cooling capacity of an absorption chiller (ACH) powered by a solar parabolic trough collector (PTC) and a backup fuel boiler by integrating thermal storage tanks. The thermal performance of the system is simulated for a building that is cooled for 14 h/day. The system uses 1000 m(2) PTC with 1020 kW ACH. Chilled water storage (CHWS) and cooling water storage (CWS) effects on the system performance for different operation hours per day of the ACH under Izmir (Turkey) and Phoenix (USA) weather conditions are analyzed. When the ACH operates 14 h/day as the load for both systems and both locations, the variations of the solar collector efficiency and the cooling load to heat input ratio remain less than 4% after the modifications. From the addition of CHWS to the reference system, a parametric study consisting of changing the ACH operation hours per day shows that the required cooling capacity of the ACH can be reduced to 34%. The capacity factor of the ACH is improved from its reference value of 41% up to 96%.