Molecular simulation study for adsorption and thermal energy storage analysis of refrigerants (R170, R161, R152a, and R143a) mixed with UIO-67 nanoparticles

Abstract

Generally, with the help of adding solid materials, the thermophysical behaviors of refrigerant can be modified. In this work, four kinds of organic refrigerants (i.e. ethane R170, 1-fluoroethane R161, 1,1-difluoroethane R152a, and 1,1,1-trifluoroethane R143a) mixed with metal–organic framework UIO-67 nanoparticles are selected as the objects, their thermodynamic energy, adsorption, desorption heat, and energy storage properties are investigated by means of molecular simulations and thermodynamic calculations. The simulation method and calculation details are elaborated. The results illustrate that the relationship between the change of thermodynamic energy and the temperature is linear, and the adsorption of refrigerants in UIO-67 can be reinforced owing to the fluorine atom in the refrigerants. However, R170, the fluorine-free refrigerant, has greater enthalpy variation of desorption than the other three refrigerants containing fluorine atom under some pressures. The thermal energy storage capacity of the refrigerant/UIO-67 mixture is greater than that of the pure refrigerant at low pressure. Meantime, as the refrigerant undergoes phase transition, the weakened improvement of the energy storage property of the refrigerant/UIO-67 mixture is found in some cases. This work can not only enrich the content of researches about metal–organic heat carrier nanofluids (MOHCs), but also provide guidance for the performance improvement and practical application of organic refrigerants.