Impact of coolant distribution design on server-level thermal management in data centers

A significant portion of data center servers (DCSs) energy is used for CPU cooling, necessitating efficient coolant distribution to optimize thermal management and improve energy efficiency. This study investigates and analyzes various coolant distribution designs for jetted cold plate cooling, with a particular focus on DCSs configured with two and four CPUs. The BBD-RSM approach effectively determines the key design parameters for optimizing cold plate configurations. In addition, the analysis provides guidance on selecting an appropriate coolant mass flow rate to enhance thermal performance and energy efficiency in CPU cooling applications. In the two-CPU case, the design with a smooth cold plate on the first CPU and a finned cold plate on the second achieves the lowest thermal resistance, improving temperature uniformity by 23.5 % and 78.5 % compared to the series and parallel arrangements, respectively. For the four-CPU case, a series design is recommended to achieve lower thermal resistance and improved temperature uniformity, while a parallel design is preferred to minimize pumping power consumption. However, a hybrid configuration that strategically uses finned cold plates results in the optimal design, reducing pumping power consumption by at least 10 % and limiting the temperature difference between the CPUs to approximately 1 K.