Heat-pump/energy-store using silica gel and water as a working pair

The possibilty of using silica gel and water as a reversible pair, in a thermochemical heatpump/energy-store has been studied theoretically and experimentally during both heating and cooling modes. With silica gel absorbing water by 25±2% of the dry silica gelʹs weight, the heat of adsorption and the heat of wetting of 2712.43 ± 30 kJ/kg SiO2 and 94.43 ± 15 kJ/kg SiO2 have been achieved respectively. The concentration rate for the two reaction pair was investigated and a general relationship that governed the adsorption rate with time has been deduced.