Studies on SAPO-34 -water working pair for adsorption refrigeration

SAPO-34 molecular sieve and water were selected as an adsorption refrigeration working pair. The adsorption isotherm of water on the SAPO-34 molecular sieve was obtained by a high-vacuum gravimetric method, and the desorption temperature was measured with Thermo Gravimetric Analyzer. The effect of regeneration temperature on refrigeration capacity was studied on a simulation device. The results indicate that the adsorption isotherm of water on SAPO-34 molecular sieve is type V in Brunauer's classification, and the equilibrium adsorption capacity can reach to 0.35 kg·kg^-1 at 30°C. The desorption peak temperature is 105°C, and the completely desorption temperature is 155°C. When the evaporation temperature was 10°C, the adsorption refrigeration capacity of SAPO-34-water working pair is 354~430 kJ·kg^-1 at the regeneration temperature of 80~120°C, which is 1.1~1.2 times higher than that of silica gel-water working pair. At regeneration temperature of 150~300°C, the adsorption refrigeration capacity of SAPO-34-water working pair is 465~523 kJ·kg^-1, which is 1.1~1.7 times higher than that of 13X-water working pair. This study indicates that the SAPO-34-water working pair can be used for refrigeration systems driven by both high temperature (>150°C) heat sources such as engine exhaust and low temperature heat sources such as solar energy.