Mesoporous silica gels for waste heat recovery and adsorption cooling of Big Data Centers

With the rise of intensive computing, the power consumption of big data centers (BDCs) has increased significantly, with 40 % being spent on cooling. This requires the development of energy-efficient technologies for cooling BDC components. Adsorption Cooling (AC) is an environmentally friendly technology that can utilize BDC waste heat to cool their components. However, the ultra-low temperature level (45–60°С) of this heat requires the search for new advanced adsorbents specialized for these harsh conditions, which is the aim of this study. Firstly, the demands for adsorbent sorption properties are formulated; the water adsorption equilibrium is compared for commercially available mesoporous silicas (pore sizes ranging from 2 to 8 nm) to select the most promising adsorbent for this cycle. At a heat rejection temperature of 30 °C, the mesoporous silica with 4.6 nm pores produces cold at T = 25 °C, sufficient for cooling BDC, with water uptake of 0.44–0.47 gH2O/gads, and can be regenerated at 50–60 °C. The main performance indexes of the cycle are assessed: the Coefficient of Performance of 0.86 and Specific Cooling Power of 0.7–3.1 kW/kg. This provides a solid foundation for the designing a compact energy-saving adsorption unit for waste heat recovery and BDCs cooling using this commercially available and cost-effective adsorbent.