Critical properties and vapor-liquid equilibrium of two near-azeotropic mixtures containing HFOs. (June 2022)

• Record Type: Journal Article
• Authors: Yang, Zhiqiang; Valtz, Alain; Coquelet, Christophe; Wu, Jiangtao; Lu, Jian
• Is Part Of: International journal of refrigeration. Volume 138(2022)
• Page Start: 133
• Page End: 147
• Publication Date: 2022-06
• Subjects: Refrigerant blend -- Low-GWP alternatives -- Vapor-liquid equilibrium -- Critical properties -- Modeling; Mélange de frigorigènes -- Alternatives à faible PRP -- Équilibre vapeur-liquide -- Propriétés critiques -- Modélisation; Refrigeration and refrigerating machinery -- Periodicals; 621.56
• DOI: 10.1016/j.ijrefrig.2022.03.027
• Languages: English
• ISSNs: 0140-7007

Abstract

Highlights: The critical properties of R1243zf + R1234yf and R1243zf + R245cb are studied based on a novel method The critical point is determined via modeling vapor-liquid coexistence points to the combined equations of the scaling law and rectilinear diameters law. Experimental VLE measurement of R1243zf + R1234yf and R1243zf + R245cb by the static-synthetic method. The R1243zf + R1234yf and R1243zf + R245cb exhibit near-azeotropic behavior within a temperature range of 293.15 to 353.15 K. Good agreement is obtained between experimental critical points and predictions from the PR-MC-MHV2 EoS. Abstract: This work studies two binary mixtures of R1243zf + R1234yf and R1243zf + R245cb which can be possibly used as a long-term alternative refrigerant for heat pumps. We present critical property (critical temperature, pressure, density) and vapor liquid equilibrium (VLE) of R1243zf + R1234yf and R1243zf + R245cb two binaries. The maximum extended uncertainties (k=2) are estimated as U( T ) = 0.21 K, U( p ) = 0.048 MPa, and U( ρ ) = 6.4 kg/m 3 for critical property measurement, and U( T ) = 0.06 K and U( p ) = 0.015 MPa for bubble point measurement. The uncertainty of liquid-phase mole fraction is estimated less than 1.8 × 10 −4 . The critical property is investigated by a novel method that determines the critical point via modeling vapor-liquid coexistence points to the combined equations of the scaling law and rectilinear diameters law. The VLE of R1243zf + R1234yf and R1243zf + R245cb binary mixtures in the range of 293.45 to 353.55 K are studied by the static-synthetic method which determines the bubble point via the variable volume cell technique. The experimental bubble points are correlated by the Peng-Robinson (PR) equation of state (EoS) with vdW and MHV2 mixing rules. The modeling results are in good agreement with the measured data. The high temperature VLE of the two binary systems is predicted up to the critical point line by PR-MC-MHV2 model with the optimal binary parameters. Graphical abstract: Image, graphical abstract