Energy saving of liquid desiccant based free cooling system in data center

Abstract

Energy Saving of Liquid Desiccant Based Free Cooling System in Data Center Park, Hyo-Lim Directed by Professor Jeong, Jae-Weon Department of Architectural Engineering The Graduate School Hanyang University The purpose of this paper is to investigate the benefits of applying a liquid desiccant system to the existing free cooling system for reducing cooling energy consumption in data centers, and to assess the feasibility of the proposed system in hot and humid regions. Tropical, subtropical, and temperate climate zones were selected as representative hot and humid regions. The proposed system consists of a liquid desiccant system, two cooling towers, a refrigeration unit, and three heat exchangers. Heat for regeneration is considered to be recovered from the waste heat generated by the refrigeration unit. The temperature of the heated solution is lowered to the target solution temperature using cooling towers. The humid and hot outside air is passed through the dehumidification section of the liquid desiccant system, reducing the humidity and humidity ratio of the outside air. The improved performance of the cooling towers, resulting from the reduced outside air humidity, allows for a lower outlet temperature compared to the reference system. The decreased outlet temperature contributes to the reduction of energy consumption by the refrigeration unit, leading to a total cooling energy reduction in the data center and an improvement in pPUE. As a result, the proposed system demonstrated an average total cooling energy reduction of 26.7% compared to the reference system in temperate, subtropical, and tropical climate zones. Consequently, an average pPUE reduction of 5.5% was achievable.