Simulation study on thermal performance of latent thermal energy storage with two-phase fluid in data center cooling system

Latent thermal energy storage (LTES) utilizing phase change material (PCM) represents an important energy-balancing technology. This paper develops a numerical model for fin-enhanced LTES and the integrated cooling system within data center. The thermal performance of the LTES and the integrated cooling system is analyzed in terms of working conditions, structural parameters, and server load. The results indicate that the PCM does not undergo complete melting and the vapor refrigerant cannot be fully liquefied within 40 minutes, given an inlet temperature range of 287.15 to 291.15 K and a flow rate between 10 and 18 L/min. The cooling capacity decreases as the transition temperature increases from 11 to 21 ℃, and increases with height difference ranging from 1.9m to 3.5m. The maximum cooling capacity increases from 4529 to 5178 W as the tube length changes from 1.0 to 1.6 times, while the PCM cross-sectional area has no effects. The cooling capacity exhibits a linear increase with rising server loads. Nevertheless, the integrated cooling system can only maintain air temperatures below the specified thermal limits for durations exceeding 15 minutes when server loads remain below 3000 W. This work demonstrates the potential application of fin-enhanced LTES and its integrated cooling systems in data centers.