Performance comparison of two absorption-compression hybrid refrigeration systems using R1234yf/ionic liquid as working pair

R1234yf (2,3,3,3-tetrafluoroprop-1-ene)/ionic liquid is a kind of environment-friendly working pair, which can overcome the disadvantages of H₂O/LiBr and NH₃/H₂O. In this work, three new working pairs R1234yf/[HMIM][TfO], R1234yf/[HMIM][PF₆], R1234yf/[HMIM][BF₄] were proposed and new solubility data for them were determined. Two new absorption-compression hybrid refrigeration systems were proposed to improve the cooling performances of the single-effect absorption refrigeration system using R1234yf/[HMIM][TfO], R1234yf/[HMIM][PF₆] and R1234yf/[HMIM][BF₄] as working pair. The effects of compressor position, compression ratio (r), generation temperature (T_g), evaporation temperature (T_e), condensation temperature (T_c) and absorption temperature (T_a) on the coefficient of performance (COP) and circulation ratio (f) were analyzed. Comparison result shows that the two systems can effectively improve the cooling performance of the single-effect absorption refrigeration system including increasing COP, reducing the heat load of condenser and f, and enlarge the operation range of T_g, T_a, and T_e. Putting compressor between evaporator and absorber is a better choice than putting it between generator and condenser. R1234yf/[HMIM][TfO] shows better cooling performance than R1234yf/[HMIM][PF₆] and R1234yf/[HMIM][BF₄] due to its favorable thermophysical properties.