Study on influence of operating parameters of data center air conditioning system based on the concept of on-demand cooling

Abstract

Abstract To improve energy efficiency of data centers, an air conditioning system for the concept of demand-based on cooling was proposed. This system combines a heat pipe cooling cycle and a vapor compression cooling cycle. Besides, the evaporative condenser is used to further utilize the natural cooling source, and the evaporator is put into the rack to realize on-demand cooling. A mathematical model was established to perform simulations of the system. The results showed that the energy consumption of compressor and pump reduce with the rising of outdoor unit air flow and evaporator inlet temperature. The coefficient of performance (COP) was selected as a reference index. When the cooling capacity is 8000 W, 6400 W and 4800 W, the optimal outdoor unit air flow of the heat pipe mode is 2000 m3/h, 1400 m3/h and 800 m3/h, respectively, and that of the vapor compression mode is 4000 m3/h, 3600 m3/h and 2400 m3/h, respectively. With the rising of evaporator inlet temperature from 29 °C to 41 °C under rated conditions, the heat pipe mode COP increased by 30.11%, 13.52% and 6.30%, respectively, and the vapor compression mode COP increased by 74.65%, 82.12% and 90.97%, respectively.