Adsorption dynamics of MOF coatings for waste heat driven cooling
Adsorption chillers are a promising option for environmentally friendly data centre cooling allowing for high energy efficiency. Waste heat from liquid cooled CPUs (~60 °C) drives the cooling for auxiliary loads (~20 °C) with heat rejection around 30 °C. Adsorption properties of the metal-organic frame work (MOF) aluminium fumarate largely outperform the state-of-the-art material silica gel at these temperatures. With adsorbent coatings, volume and mass specific cooling power may be increased to reduce specific costs. Samples were prepare with a binder-based aluminium fumarate coating in three different thicknesses (140-610 mm) and measured for adsorption dynamics with large-temperature-jump-experiments. Uptake-times (15-85%) are in the range of 9-78 s. On a full scale heat exchanger expected volume and adsorbent mass specific cooling powers are 200-700 W l-1 and 1.3-14 kW kg-1 - an increase to state-of-the-art of 3-10 times and >10 times at reasonable cooling COPs of 0.47-0.57.