Nanorefrigerant is a mixture of nanoparticles and pure refrigerant, which can increase heat transfer characteristics in refrigeration and air conditioning equipment. The performance of four different Al₂O₃ nanorefrigerants and their pure fluids (R600a, R134a, R1234yf, and R1233zd(E)) is analyzed in a vapor-compression refrigeration cycle. The enthalpy of a nanorefrigerant in the refrigeration cycle is calculated by using the prediction method based on the density of nanorefrigerant. A numerical model is established for the thermodynamic analysis, and the results show that adding nanoparticles to the pure refrigerant enhances heat transfer in heat exchangers, increases cooling capacity, reduces compressor power consumption, and finally improves the performance of the refrigeration system. The COP improvement of R1233zd(E) + Al₂O₃ nanorefrigerant is the highest, and the COP improvement of R134a + Al₂O₃ and R1234yf + Al₂O₃ are close to each other. When the mass fraction of Al₂O₃ nanoparticles increases to 0.30%, the COP of R1233zd(E) and R600a increases by more than 20%; the maximum exergy efficiency is 38.46% for R1233zd(E) + Al₂O₃, and the minimum exergy efficiency is 27.06% for pure R1234yf. The results provide a basis for the application of nanorefrigerants in the vapor compression refrigeration cycle.