Studies on environmentally benign adsorption refrigeration working pairs and their refrigeration performance

Composite adsorbents (M4-0132, MI-9906, MI-0001 and M2-0003), which demonstrate favorable adsorption refrigeration performance, were prepared through combining a series of main adsorptive materials, such as 13X molecular sieve, concavo-convex stick stone and strontium chloride. Adsorption isotherms of water or ethanol on composite adsorbents were determined. According to the fitting parameters of the adsorption isotherms, the calculations show that the characteristic adsorption work of self-prepared composite adsorbents-water adsorption working pairs is about 12%-29% that of 13X molecular sieve-water pair, and that of composite adsorbents-ethanol pairs is approximately 10%-20% that of activated carbon-ethanol pair. The stable state equilibrium equation for adsorption refrigeration system (liquid-vapor-adsorbent) was set up. The favorable refrigeration systems (situations) of working pairs, consisted of water and ethanol with composite adsorbents, were discussed, and the results show that: M4-0132-water and Ml-0001-water pairs can be utilized for refrigeration system requiring larger cooling cycle volume, i.e air conditioning system, while Ml-9906-ethanol and M2-0003-ethanol pairs are more preferable to low-temperature refrigeration system, i.e ice-making and chilling system. Adsorption refrigeration volume of Ml-9906-water pairs is 2.0-2.5 times that of 13X-water. Regenerated at temperature of 60-120°C, adsorption refrigeration volume of M4-0132-water pairs is 441-924kJ·kg^-1, while regenerated at 40-100°C, said cooling volume of Ml-0001-alcohol pairs is 315-909kJ·kg^-1, which is 2.2-5.9 times that of activated carbon-ethanol pairs.