THERMODYNAMIC PROPERTIES OF LIQUEFIED PETROLEUM GASES (LPG)

The thermodynamic properties of serveral liquefied petroleum gases (with particular emphasis on propane) are discussed in detail. It is concluded that the widely used propane data by Stearns and George are too inconsistent and too inaccurate to be used for mass flow calculations of propane and propane mixtures through safety valves of rail tank cars. Accordingly, the thermodynamic properties of propane, propylene, n-butane, and a mixture of 65% (by mole) propane, 25% propylene, and 10% n-butane are recalculated using equations of states proposed by Benedict-Webb-Rubin (BWR) and by Starling. It is shown that Starling's equation results in thermodynamic properties which are more consistent and compare better with measured values than the BWR equation. Thermodynamic data for the four liquefied petroleum gases discussed above are calculated and presented in tabular form. In addition, predictions of pure propane mass flow rates (based upon isentropic), homogeneous equilibrium flow) are given. The influence of the thermodynamic data upon the predicted mass flow rates is demonstrated.

• Record URL:
  https://railroads.dot.gov/elibrary/thermodynamic-properties-liquefied-petroleum-gases
• 
• Corporate Authors:

  University of Maryland, College Park

  Department of Mechanical Engineering
  College Park, MD  United States  20742

  Federal Railroad Administration

  Office of Research and Development, 1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Sallet, D W
  • Wu, K F
• Publication Date: 1980-4

Media Info

• Media Type: Digital/other
• Features: References;
• Pagination: 99 p.

Subject/Index Terms

• TRT Terms: Flow measurement; Fluid dynamics; Liquefied petroleum gas; Measurement; Propane; Railroad safety; Safety valves; Tank cars; Thermal properties; Thermodynamics
• Old TRIS Terms: Lpg measurement; Lpg properties; Tank car safety
• Subject Areas: Marine Transportation; Materials; Railroads; Safety and Human Factors;

Filing Info

• Accession Number: 00312192
• Record Type: Publication
• Report/Paper Numbers: FRA-ORD-76-299 Intrm Rpt.
• Contract Numbers: DOT-FR-64181
• Files: TRIS, USDOT
• Created Date: Aug 27 1980 12:00AM