Metal-organic frameworks demonstrate significant application potential in sorption refrigeration driven by low-grade thermal energy owing to their ultrahigh specific surface area

large pore volume

and adjustable structure. Among the most structurally stable MOFs

ZIF-8(Zn) exhibits excellent structural stability and stable sorption properties. Herein

the grand canonical Monte Carlo molecular simulation method is adopted to simulate the sorption reaction between ZIF-8(Zn) and NH3

which is described by the universal force field and transferable potentials for phase equilibria force field parameters

respectively. Using both molecular simulation results and the adsorption refrigeration thermodynamic cycle model

we investigate the adsorption and refrigeration performances of the ZIF-8(Zn)/NH3 working fluid pair. The results show that the isothermal ammonia sorption capacity of ZIF-8(Zn) increases with pressure and that the sorption capacity reaches 0.305 g/g and 0.231 g/g at 298 Kand 398 K

respectively. Moreover

the total heat of sorption at the same temperature increases with pressure owing to the increase in the reaction heat of the NH3 intermolecular interaction. The isothermal sorption heat from the interaction between ZIF-8(Zn) and NH3 is relatively stable at different pressures. Furthermore

the sorption density distribution diagram shows that numerous NH3 molecules are adsorbed at the metal sites. Some NH3 molecules fail to pass through the small channels of ZIF-8(Zn)

whereas others accumulated inside the six-membered ring cage of ZIF-8(Zn) after passing through the holes. Finally

the sorption refrigeration system demonstrates stable refrigeration performance and good adaptability to refrigeration temperatures. Ideally

the coefficient of performance (COP) should be 0.43 when the refrigeration temperature is 283 K (ventilation conditions)

and it should be able to reach 0.38 when the refrigeration temperature is 243 K (freezing conditions).