Impact of Storage Tank Size and Backup Heating Unit on a Solar Absorption Cooling System

Solar energy has a great ability in cooling and air conditioning as the demand for cooling and air conditioning coincides with the availability of solar energy. In this study, a simulation program using TRNSYS platform was built to simulate and optimize the design and operating parameters. The hourly thermal performance of a single stage LiBr/H2O solar absorption cooling system powered by linear Fresnel Concentrator was investigated under Cairo climate. The components size of the solar absorption cooling plant was optimized. The performance of the cooling system was studied in terms of the rate of useful energy from the concentrator, of the collector outlet temperature, and the coefficient of the performance COP of the absorption chiller. From the study, it was found that the optimum storage tank capacity depends on the area of the solar concentrator. Increasing the storage tank capacity from 3 to 9 m3 leads to a decrease in the maximum outlet temperature from the collector from 182 to 120 oC and consequently decreasing the Absorption chiller COP from 0.46 to 0.07 respectively. Supplying a gas backup heating unit ensures stability for powering the adsorption cooling system. Increasing the backup unit capacity increase the operating hours of the absorption chiller.