Energy-saving and economic analysis of the data center cooling system using magnetic bearing chillers under different climate conditions

Abstract

Magnetic bearing chiller has excellent Coefficient of Performance, but the high initial investment makes it challenging to find a balance between energy-saving efficiency and economic potential. This paper proposes two energy-saving retrofits with water-side economizers, using efficient centrifugal chillers (Plan 1) and magnetic bearing chillers (Plan 2), respectively, to replace the existing cooling system of a case data center in Nanchang. Energy models of three cooling systems are developed to analyze the energy efficiency and performance. Compared to the existing cooling system, the operation time of Full free cooling and Partial free cooling for Plan 1 and Plan 2 reach 2489 and 1324 h, respectively. Result in energy savings of 63.19 % and 64.54 %, and power usage effectiveness reduce 0.341 and 0.349, respectively. Because the annual chiller COP of Plan 2 is 6.7 % higher than that of Plan 2, Plan 2 saves additional 3.96 % annual energy consumption compared to Plan 1. Furthermore, the energy-savings and economy of the retrofit plans in five typical climate cities in China are discussed. The energy savings rates for Plan 1 and Plan 2 are 61.4%–64.7 % and 62.1%–65.6 %, respectively, and their dynamic payback periods are 2.02–5.15 years and 2.16–5.6 years.

Keywords

• Data center
• Free cooling
• Magnetic bearing chiller
• Economic analysis