Thermal Analysis of a Solar Absorption Cooling System with Hot and Cold Storage Tanks
Keywords:building cooling load, solar parabolic concentric collector, absorption system, water-lithium bromide solution, ambient temperature
In the present work, a numerical model is carried out to investigate the performance of a cooling system for a building. The system is operated by a solar powered absorption cooling system using a solar parabolic concentric trough collector integrated with the thermal storage tanks. The system selected a single-effect absorption cooling system has a cooling capacity of 7 kW and working with both hot storage tank in the solar collection loop and cold storage tank in the load loop. A transient system modular computer program has been developed for the cooling system to predict optimal operating conditions of the cooling system working in combination with thermal storage tanks. In this cycle, the hot storage tank is used to store the extra energy and thus to be used to operate the absorption system after the sunset. A cold storage tank is used to store the extra coolant water to cool the building at night time. The building area is 40 m2 and its load is calculated hourly in the steady region of Tikrit University, north of Iraq. The thermal storage tanks volume (cold and hot) ranges (0.2 to 1.25 m3) and this is done for an area range (10 to 30 m2) of parabolic concentric trough collector. The results showed that the typical volume of hot storage tank equals to 0.23 m3 and the cold storage tank volume is 0.57 m3 at a minimum solar collector area 16.6 m2 to condition the building during most of the day hours from 11 AM to 6 PM. The maximum value of the (COP) is 0.65 based on the optimum parameters.