Experimental study on reducing energy consumption of air conditioning system in micro-module data centers using urban raw water

This study utilizes urban raw water as the cold source for data center air conditioning. The existing air-cooled direct expansion system in a micro-module data center is retrofitted into a water-cooled direct expansion system, and the new configuration is established. To meet hygienic standards for raw water and ensure easy maintenance of heat exchangers, a novel heat pipe heat exchanger is designed to achieve indirect heat transfer. Under identical indoor conditions, operational parameters of both air-cooled and water-cooled systems are compared. The results show that at typical conditions (35.3 ℃ ambient temperature, 23.1 ℃ raw water temperature), the retrofitted water-cooled system achieves 36.59% higher EER than the air-cooled system. Across varying ambient temperatures (26.1-35.3 ℃) and raw water temperatures (20.4-23.1 ℃), the water-cooled system maintains EER between 3.86-4.35, representing 15.08%-36.59% efficiency improvement. These findings demonstrate that using temperature-stable urban raw water effectively reduces cooling energy consumption and carbon emissions in urban data centers.