Thermal performance of refrigerant pump-driven free cooling system for data centers with mixed refrigerant

Abstract

Refrigerant pump-driven free cooling technology can effectively reduce data center cooling energy consumption. But for a pure refrigerant system, it is difficult to meet the need of dynamic high efficient operation facing both the large temperature difference range and multiple operating modes yearly. In order to improve the energy efficiency of the system and the utilization of free cooling source, an experimental system of refrigerant pump-driven free cooling for the data center was built up. The thermal performance of the system charged with R410A mixed refrigerant was tested and analyzed under different working conditions. The results show that the cooling capacity and EER of the system increases with the increasing of the temperature difference between cold and heat sources. The cooling capacity increases firstly and then decreases slightly, then changes little within the pump frequency range of 5～30 Hz. The pump frequency for maximum cooling capacity occurs in the range of 10～15 Hz for R410A system, which is 25 Hz for R22 system.

Keywords

• data center
• refrigerant pump
• free cooling
• mixed refrigerant
• operational performance