Numerical and Experimental Investigation of Desiccant Cooling System Using Metal Organic Framework Materials

Evaporative cooling consumes fraction of the electricity required by the vapour compression refrigeration system but is only effective in dry weather conditions. A promising method for controlling the incoming air humidity is to use a desiccant wheel before the evaporative cooler. Currently, most desiccant cooling systems employ conventional materials like silica gel or zeolites which have low water uptake. Metal Organic Framework (MOF) materials are new class of meso-porous material with high water adsorption capabilities (~1.5kg/kgads). Using numerical modelling and experimental testing, this paper investigates the use of three MOF materials namely CPO27(NI), MIL100(Fe), and Aluminium Fumarate and silica gel on the performance of stationary desiccant wheel (honeycomb Aluminium structure coated with MOF desiccant material) in terms of the moisture removal rate and Coefficient of performance (COP). Numerical results showed that the Aluminium fumarate produced the highest water removal rate of 12.65g/kg dry air and COP of 0.65 compared to silica gel and other MOF materials used. Experimental tests were carried out using honeycomb structure coated with Aluminium fumarate as the stationary desiccant wheel and results were compared to numerical modelling showing good agreement with maximum deviation of 13%. Experimental and modelling results showed that the rate of moisture removal increases with the increase of air inlet humidity and with the decrease of air speed. In terms of the dynamic performance of the desiccant wheel, results showed that the highest moisture removal occur after 2 minutes