Determination of the Thermophysical Properties of Nsukkanut: A Solid Absorbent for Solar Refrigeration
The thermophysical properties of 'Nsukkanut', - a CaCl2/CaSO4 absorbent mixture used in solid absorption solar refrigeration , were studied in this report. The transient experimental technique of Beck and Al-Araji  was used in determining the effective thermal conductivity, specific heat and bulk thermal diffusivity of granular (2.8 - 6.35 mm sizes) parkings of the absorbent. Additionally, the parking density crushing stress percentage swell and degree of refrigerant - NH3 absorption were determined. Effective k, c and a values were in the ranges of 0.098 - 0.111 W/mk, 1.123 -1.696 kJ/kg K and 1.404 - 1.053.10-7 m2/s, respectively, for a parking density of 621.4 kg/m3. Average crushing stress, the percentage swell and absorption factor values 018.17 N/mm2, 7.96% and 62.1 % respectively, obtained in this report compared well with values of 8.10 N/mm2, 11.6% and 59.5% correspondingly, as reported in .
The effect of aluminium as a thermal conductivity improvement additive, on the thermophysical properties of the absorbent, were also studied. For aluminium fractions of up to 3% by mass, no sustained improvement in thermal properties were observed, while the strength and swell properties deteriorated.