The Relations Used to Analyze the Phase Equilibrium Properties of Binary Refrigerant Mixtures

At present, the method adapted to analyze the phase equilibrium properties of refrigerant mixtures is as follows: Firstly, based on some experimental data of· phase equilibrium, the interactire factor bet~een the mixed refrigerants can be derived by using a equation of stalL Second!~ the rapour and liquid phase equilibrium properties are predicted by combining the mixed rule with phase equilibrium condition of mixture. Because the rtlue of interactire factor for mixture raries as the different temperature ud the concentution, the deTiation between the calculated results and metsured ralues is obrious. In thia paper, first of dl, the mathematict! model of. actirity-coefficient for the binary refrigerant mixture has been built on the basis of the statistical mechanics theory. Then, the relation• used to calculate the phase equilibri~~ properties of sttursted rapour and liquid for binary refrigerant mitture, whose undefined conttants were determined by regressing the measurad dtta, hiTe been found. Finaly, some phase equilibrium properties of mitture Rl2/R!!ij and R22/Rll4 ht'e been predicted by using abore relations, and the calculated results agreed with the llleasured nlues. !. NOMENCLATURE r ------Actirity coefficient; x -------Mole concentration of component A in liquid phase; R ------Gas constant; T ------Temperature, K; N ------ATogadro• 1 number; Z ------Number of neibouring molecule to enclose the mixture molecular: Q -------Work needed by neibouring molecula~ • maTing in mixing process; Tr -----Reduced temperature; A,B -----Component A and B. 2. INTRODUCTION At present, mixture refrigerant play lll important role in