Impact of a vertical geothermal heat exchanger on the solar fraction of a solar cooling system

This paper presents the influence on the solar fraction of coupling a Solar Cooling System (SCS) with a Geothermal Heat Exchanger (GHX). The SCS analysis was made using a mathematical model and was supported by experimental data of a vertical GHX. First, the cooling capacity of the SCS was calculated, considering the cooling load required for a building of 420 m3. The results show that a 12.30 kW cooling capacity SCS would be necessary to satisfy the maximum cooling load requirement during the summer. A 1 kW PV array was considered to assist the SCS. With the constructed GHX a soil temperature model was validated to estimate the temperature of the output water at different GHX depths. The solar fraction meets between 10 and 23% of the energy demand when the condenser is air cooled. However, when a GHX of 1, 2, 4 and 10 m is implemented the solar fraction increases.