Numerical and Experimental Investigation of a Novel Liquid Upper-Feeding Micro-Channel Flat Loop Thermosyphon Cooling and Heat Recovery System

Abstract

A novel liquid upper-feeding micro-channel flat loop thermosyphon (LUF-MCFLTS) system was developed, to eliminate the ‘dry-out’ phenomenon of the upper surface in the traditional LTS and provide a high-efficient solution for DC cooling and heat recovery. The effects of cooling capacity (cooling water flow rate and temperature), heat load and filling ratio on the heat transfer performance of the LUF-MCFLTS system are investigated experimentally. The results indicated that with the increase of cooling water flow, the decrease of cooling water temperature and the increase of heat load, the heat transfer performance of the LUF-MCFLTS system was better. Under the heat load of 500 W, cooling water flow rate of 600 L/h and cooling water temperature of 15°C, the heat recovery efficiency could reach 86.28%. Compared with the MCFTS and MCFLTS system in literature, the recovery efficiency of LUF-MCFLTS system could be increased by 31.6% and 2.64%, respectively, since it allows a uniformly distributed liquid film on the upper wall of evaporator, thus keeping the upper wall constantly wet and improving film evaporation. In addition, an effective numerical model to predict the heat recovery efficiency of the LUF-MCFLTS system with the experimental data in the 2.07% error band has been established.

Keywords: LUF-MCFLTS system, Cooling and heat recovery, Data centre, Numerical model, Heat recovery efficiency