Investigation on the two-phase loop cooling system composed of maglev compressor and liquid pump for data centers

Abstract

• The cooling system composed of maglev compressor and liquid pump is proposed. • The two-phase loop cooling system is oil free and structurally reliable. • As pressure ratio varies from 2.64 to 1.13, system COP increases from 3.85 to 8.16. • The outdoor unit COP is 31∼40 and the system COP is above 12 in pump-driven mode. • The annual GCOP is above 6.5 and PUE is 1.2 or less in most climate zones of China. The increasing demand for data processing, storage and distribution is escalating the energy usage of data centers, in which cooling system energy consumption could take up 30%∼50% of the total energy consumption. In this regard, improving cooling system efficiency will contribute to the optimization of energy utilization. In this paper, a two-phase loop cooling system driven by maglev compressor and liquid pump, which is oil free and structurally reliable, is proposed and investigated experimentally. The system performance under three different operating modes is explored experimentally. The application effects of proposed system in typical climate zones of China are analyzed. The results show that the coefficient of performance (COP) of the system is about 12 and the COP of the outdoor unit is as high as 31∼40 in pump-driven mode. In integrated mode and vapor compression mode, the COP of system increases from 3.85 to 8.16 while pressure ratio varies from 2.64 to 1.13, which means that the maglev compressor and the liquid pump can cooperate well to achieve an expected performance. The annual COP of the integrated system applied in China is above 6.5 in most climate zones. The power usage effectiveness of data center can be as low as 1.2, under the assumption that the energy consumption of auxiliary system except the cooling system accounts for 5% of the information technology equipment energy consumption.