Investigation on innovative thermal conductive composite strontium chloride for ammonia sorption refrigeration

A novel composite strontium chloride (SrCl2) is developed with porous material of expanded natural graphite (ENG) and nanoparticle of carbon coated nickel (Ni@C) as the additives. Thermo-physical properties such as thermal diffusivity, thermal conductivity and permeability are investigated and analyzed. The highest thermal diffusivity could reach 6.2 mm2⋅s−1. Correspondingly the highest thermal conductivity is 4.03 W ⋅ m−1 ⋅ K−1, which is about 20 times higher than that of granular SrCl2. Permeability of novel composite SrCl2 ranges from 1.31 × 10−9 m2 to 1.07 × 10−13 m2. Moreover, samples with Ni@C have better sorption performance in ammonia than those without Ni@C due to the improved heat and mass transfer performance. Ammonia sorption quantities of novel composite SrCl2 range from 0.39 kg⋅kg−1 to 0.67 kg⋅kg−1 when evaporation temperature varies from −15 °C to 15 °C. The addition of ENG and Ni@C shows great potentials for sorption refrigeration by adjusting the concentration swing.