Performance investigation of a biomimetic latent heat thermal energy storage device for waste heat recovery in data centers

Improving the power usage effectiveness of data centers has become a significant challenge for carbon peaking and carbon neutrality. To address this, here we propose a single-phase immersion cooling system with latent heat thermal energy storage (LHTES) devices to recover waste heat. Furthermore, an innovative LHTES device with palmate leaf-shaped fins is designed by bionic techniques. The phase change behavior and thermal transport patterns of biomimetic and traditional LHTES devices are investigated, and the effects of the arrangement and working conditions are revealed. Additionally, the proposed solution's application prospect and economy are presented. The results indicate that the performance of palmate leaf-shaped finned LHTES devices is significantly enhanced compared to traditional ones, whose charge and discharge durations reduce by 21.0 % and 38.2 %, respectively. Moreover, the natural convection development enhances the melting performance, but its effect on solidification processes is insignificant. Considering the trade-off between power consumption and LHTES efficiency, a horizontal biomimetic LHTES device with a flow rate of 20 L/min and a large heat-transfer temperature difference is suggested in practical engineering. Notably, the maximum reduction in annual power consumption for using biomimetic LHTES devices is 2397.4 kW center dot h, and the minimum payback period is only 2.0 years.