A new combination of a solar-powered adsorption cooling system with a geothermal cooling source

When using water to cool adsorption cooling systems, it is necessary to have a permanent source of cold water or to utilize cooling towers, which consume large amounts of water due to evaporation in the process of evaporative water cooling. Therefore, many scientists focus on how to use sustainable sources of cold water, such as geothermal cooling, which is one of the most promising sources for energy system applications. The study presents a novel method for combining solar heating and geothermal cooling in Lebanon, utilizing adsorption cooling to enhance the efficient use of renewable resources. Geothermal cooling energy is primarily used to cool the condenser of the adsorption chiller, in addition to removing the heat of adsorption during the adsorption process. The effects of the diameter and length of the ground-cooling water pipes, as well as the water velocity, on the ground-cooling water temperature are investigated. Then, the impact of changes in ground-cooling water temperature on the performance of the adsorption cooling system is studied. The paper also presents theoretically the performance of the adsorption cooling system in Lebanon’s climate. The results illustrate that coupling geothermal cooling with a solar-powered adsorption cooling system increases the cooling capacity to 21.6 kW, with an improvement of about 44% compared to the traditional adsorption system with a cooling tower. The proposed combination raises the coefficient of performance (COP) to 0.52, with an enhancement of about 11.6% at a regeneration temperature of 85 °C. An additional advantage of this coupling is that the system can operate efficiently at a low hot source temperature of 50 °C with a COP of 0.55. This research demonstrates that solar energy and geothermal cooling sources can be efficiently utilized to power hybrid adsorption cooling systems. This approach not only promotes electrical power savings but also leverages renewable and environmentally friendly resources, potentially advancing these industries in the future.