Energy and exergy analysis with environment benefit of the underground cooling system of the chiller plant

Abstract

Using an underground heat exchanger as an alternative to a wet cooling tower can offer several benefits, particularly in terms of energy efficiency and environmental impact. Heat exchangers and cooling towers are chosen depending on various factors, such as the application size, local climate conditions, and economics. The purpose of this study is to compare the use of an underground heat exchanger with a wet cooling tower for cooling purposes. The underground heat exchanger and wet cooling tower provide cooled water for vapor compression chillers. The comparison is conducted on technical, economic, and environmental grounds. Research has been conducted in the Mashhad region, where water resources are limited and cooling demands are high during the summer. In this context, Ferdowsi University of Mashhad is selected as a case study. Energy and water consumption are calculated and compared by simulating and modeling both methods of producing cooled water and the refrigeration cycle. However, improving the alternative mode's exergy efficiency was discussed for all system components. The findings reveal that using the underground heat exchanger results in a 14% reduction in energy consumption and eliminates water consumption. The current water-cooled compression chillers consume approximately 1.95 cubic meters of water per square meter of the building daily.