Study of hybrid geothermal cooling system

Using renewable energy for heating and cooling applications covers the increasing demand of energy sources. In the present study, numerical analysis is used to study 9 closed-loop geothermal air pipe system cases during summer and winter with different pipe geometry of diameters of 0.17, 0.35, and 0.65 meters and total pipe lengths of 47, 64 & 87 meters for air conditioning application. The conditioned air is then supplied to a room of Length 3m x Width 3m x Height 3m. The numerical model is combined with a 1 m length solar chimney of 45ᵒ inclination angle. Also, an experiment was conducted in Damanhur city, Beheira Governorate, Egypt, providing conditioned air to a room of L 2m x W 2m x H 2m via a 5 m long, 5.3 mm thick geothermal PVC air pipe of 2 inches in diameter. The pipe was buried at 2 m depth and was supported by the solar chimney during winter to provide natural draft force inside the closed-loop system and to support the heating process. On the other hand, the closed loop contains a driving fan to provide circulation during summer. The results of the numerical model prove that the numerical analysis showed the highest level of air conditioning temperature difference close to 5 ᵒC for the case of 0.65 m diameter pipe, and 87 m total length. The validation of the numerical model was carried out using experimental results.