Thermodynamic property formulations and heat transfer aspects for replacement refrigerants: R-123 and R-134a

✍ Scribed by A. Stegou-Sagia

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 196 KB
• Volume: 21
• Category: Article
• ISSN: 0363-907X
• DOI: 10.1002/(sici)1099-114x(199708)21:10<871::aid-er283>3.0.co;2-i

✦ Synopsis

This paper reports analytical relations for the thermodynamic properties enthalpy, entropy, heat capacities at constant pressure and temperature of the replacement refrigerants R-123 and R-134a. These refrigerants are considered promising as substitutes for the fluids R-11 and R-12, respectively, which are two of the most widely used CFC refrigerants. In addition to the properties, the three real gas isentropic exponents k NT , k T2 , k N2 are calculated, which may be used instead of the classical exponent k"c /c in the ideal gas isentropic change equations to describe with good accuracy the real gas behaviour. A systematic study to research the influence of various parameters on heat transfer during condensation of R-123 and R-134a on horizontal integral-fin tubes is also carried out. The results are useful in refrigeration applications to improve the basic design, as a significant concern about new refrigerants to replace the CFCs has increased very rapidly due to the destruction of stratospheric ozone and global warming.