Performance analysis and optimization of a hybrid mechanical and free cooling system with cold water storage for a data center

With the rapid development of the data center industry, the associated issues of high energy consumption and operational costs have become increasingly severe, significantly impacting the sustainability of data centers. To address this problem, a hybrid mechanical and free cooling system integrated with cooling storage for a data center is proposed, and a TRNSYS model is established to analyze its energy-saving effect. The results show that the PUE value of the system is reduced by 0.057 and the energy saving ratio of the cooling system reaches 19.22%, compared to a pure mechanical cooling system. Analysis of the impact of the volume of the storage tank on energy-saving effects reveals that as the volume increases, the PUE generally trends downward. When the volume is increased to 7.5 times its initial size, the PUE decreases by 0.0025, and the energy saving ratio reaches 1.12%. Subsequently, the control strategy and the size of the cold water storage tank in the model are optimized using a hybrid optimization algorithm. The results indicate that, following optimization, both the energy saving ratio and the electricity cost saving ratio of the cooling system reach 27.65%, while the PUE is reduced by 0.076.