Experimental study on thermal characteristics of thermosyphon with water condenser and LTES condenser in parallel (TWCLC)

Abstract

Since the servers' workload of the data center varies over time, the cooling system needs to be adjusted according to the on-demand cooling load. Thermosyphon integrated system is efficient in meeting the time-varying cooling load, and thermal energy storage is one of the important methods to eliminate the overheating load. To deal with the time-varying cooling load, a novel integrated thermosyphon with water condenser and latent thermal energy storage (LTES) condenser in parallel (TWCLC) is developed and experimentally studied. The effects of refrigerant filling ratio and inlet conditions on thermal performance are analyzed. With the increase of the refrigerant filling ratio ranging from 52.1 % to 80.2 %, the cooling capacity of TWCLC decreases. The LTES condenser enhances and then weakens the cooling capacity of TWCLC, by a maximum of 18.1 % improvement compared with the water-cooled thermosyphon. The subcooling temperature of the TWCLC is lower than that of the water-cooled thermosyphon; the superheating temperature is always zero. The water flow rate and water temperature have little effect on the cooling capacity of TWCLC. But it could not start up in due course with inlet cold water temperature higher than 16 °C. With the increases of the inlet air temperature and air flow rate, the cooling capacity of the evaporator side increases due to the common function of the water condenser and LTES condenser.