0
Technical Brief

Revisiting the Compressibility of Oil/Refrigerant Lubricants

[+] Author and Article Information
Scott Bair

Georgia Institute of Technology,
Center for High-Pressure Rheology,
George W. Woodruff School of Mechanical Engineering,
Atlanta, GA 30332-0405
e-mail: scott.bair@me.gatech.edu

Mark Baker

CPI Fluid Engineering,
a Division of the Lubrizol Corporation,
2300 James Savage Road,
Midland, MI 48642
e-mail: MRBA@CPIfluideng.com

David M. Pallister

CPI Fluid Engineering,
a Division of the Lubrizol Corporation,
2300 James Savage Road,
Midland, MI 48642
e-mail: DAPAL@CPIfluideng.com

1Corresponding author.

Contributed by the Tribology Division of ASME for publication in the JOURNAL OF TRIBOLOGY. Manuscript received February 19, 2016; final manuscript received March 10, 2016; published online August 11, 2016. Assoc. Editor: Ning Ren.

J. Tribol 139(2), 024501 (Aug 11, 2016) (4 pages) Paper No: TRIB-16-1060; doi: 10.1115/1.4033335 History: Received February 19, 2016; Revised March 10, 2016

A fixture was fabricated for the purpose of restraining the expansion of an existing metal bellows piezometer so that a refrigerant and oil mixture can be admitted under pressure. Measurements on a polyol ester (POE) with 9.2 wt.% of R134a show that the addition of refrigerant slightly increases compressibility. The previously reported reduction in compressibility (increase in bulk modulus) by Tuomas and Isaksson (2006, “Compressibility of Oil/Refrigerant Lubricants in Elasto-Hydrodynamic Contacts,” ASME J. Tribol., 128(1), pp. 218–220) of an ISO 68 POE when mixed with R134a cannot be supported by precise measurements of the volume compression. The increased compressibility found by Comuñas and co-workers (2002, “High-Pressure Volumetric Behavior of x 1, 1, 1, 2-Tetrafluoroethane + (1 − x) 2, 5, 8, 11, 14-Pentaoxapentadecane (TEGDME) Mixtures,” J. Chem. Eng. Data, 47(2), pp. 233–238) is the correct trend. The Tait equation of state (EoS) has been fitted to the data for both the neat POE and its 9.2% by weight mixture with refrigerant. The usual problem was encountered for the mixture with the Tait EoS at low pressure where the compressibility becomes greater than predicted due to proximity to the vapor dome. The measured relative volumes of the mixture can be used to collapse the viscosity to a master curve when plotted against the Ashurst–Hoover thermodynamic scaling parameter. The thermodynamic scaling interaction parameter is approximately the same as for the neat oil.

FIGURES IN THIS ARTICLE
<>
Copyright © 2017 by ASME
Your Session has timed out. Please sign back in to continue.

References

Bair, S. , Fernandez, J. , Khonsari, M. M. , Krupka, I. , Qureshi, F. , Vergne, P. , and Wang, Q. J. , 2009, “ Letter to the Editor: An Argument for a Change in Elastohydrodynamic Lubrication Philosophy,” Proc. Inst. Mech. Eng., Part J, 223(4), pp. i–ii.
Bair, S. , Vergne, P. , Kumar, P. , Poll, G. , Krupka, I. , Hartl, M. , Habchi, W. , and Larsson, R. , 2015, “ Comment on History, Origins and Prediction of Elastohydrodynamic Friction by Spikes and Jie,” Tribol. Lett., 58(1), pp. 1–8. [CrossRef]
Yamamoto, Y. , Gondo, S. , and Kim, J. , 2001, “ Solubility of HFC134a in Lubricants and Its Influence on Tribological Performance,” Tribol. Trans., 44(2), pp. 209–214. [CrossRef]
Muraki, M. , and Sano, T. , 2000, “ Determination of Film Thickness and Traction of Polyol Ester Under an EHD Contact in Some Refrigerant Environments,” Tribol. Trans., 43(1), pp. 15–20. [CrossRef]
Bair, S. , and Laesecke, A. , 2012, “ Normalized Ashurst–Hoover Scaling and a Comprehensive Viscosity Correlation for Compressed Liquids,” ASME J. Tribol., 134(2), p. 021801. [CrossRef]
Bair, S. , 2014, “ Density Scaling of the Thermal Conductivity of a Jet Oil,” Tribol. Trans., 57(4), pp. 647–652. [CrossRef]
Tuomas, R. , and Isaksson, O. , 2006, “ Compressibility of Oil/Refrigerant Lubricants in Elasto-Hydrodynamic Contacts,” ASME J. Tribol., 128(1), pp. 218–220. [CrossRef]
Jacobson, B. O. , 2000, “ A New High Pressure Chamber for Lubricant Investigations,” International Tribology Conference, Nagasaki, Japan, pp. 1199–1202.
Comuñas, M. J. , Baylaucq, A. , Boned, C. , Canet, X. , and Fernández, J. , 2002, “ High-Pressure Volumetric Behavior of x 1, 1, 1, 2-Tetrafluoroethane+(1-x) 2, 5, 8, 11, 14-Pentaoxapentadecane (TEGDME) Mixtures,” J. Chem. Eng. Data, 47(2), pp. 233–238. [CrossRef]
Bair, S. , 2016, “ A New High-Pressure Viscometer for Oil/Refrigerant Solutions and Preliminary Results,” Tribol. Trans. (accepted).
Ashurst, W. T. , and Hoover, W. G. , 1975, “ Dense Fluid Shear Viscosity and Thermal Conductivity—The Excess,” AIChE J., 21(2), pp. 410–411. [CrossRef]
Bair, S. , 2007, High Pressure Rheology for Quantitative Elastohydrodynamics (Tribology Series), Vol. 54, Elsevier, Amsterdam, pp. 60–61.
Lemmon, E. W. , McLinden, M. O. , and Friend, D. G. , 2005, “ Thermophysical Properties of Fluid Systems,” NIST Chemistry WebBook, P. J. Linstrom and W. G. Mallard , eds., National Institute of Standards and Technology, Gaithersburg MD.
Diogo, J. C. , Avelino, H. M. , Caetano, F. J. , Fareleira, J. M. , and Wakeham, W. A. , 2016, “ Tris (2-Ethylhexyl) Trimellitate (TOTM) as a Potential Industrial Reference Fluid for Viscosity at High Temperatures and High Pressures: New Viscosity, Density and Surface Tension Measurements,” Fluid Phase Equilib. (in press).
Bair, S. , 2016, “ The Temperature and Pressure Dependence of Viscosity and Volume for Two Reference Liquids,” Lubr. Sci., 28(2), pp. 81–95. [CrossRef]
Bair, S. , 2014, “ The Pressure and Temperature Dependence of Volume and Viscosity of Four Diesel Fuels,” Fuel, 135, pp. 112–119. [CrossRef]
Habchi, W. , and Bair, S. , 2013, “ Quantitative Compressibility Effects in Thermal Elastohydrodynamic Circular Contacts,” ASME J. Tribol., 135(1), p. 011502. [CrossRef]
Bair, S. , 2016, “ High Pressure Viscosity Measurements of Refrigerant/Oil Solutions,” Final Report to CPI Fluid Engineering, Georgia Institute of Technology, Atlanta, GA.
Laesecke, A. , and Bair, S. , 2011, “ High-Pressure Viscosity Measurements of 1, 1, 1, 2-Tetrafluoroethane,” Int. J. Thermophys., 32(5), pp. 925–941. [CrossRef]
McEwen, E. , 1952, “ The Effect of Variation of Viscosity With Pressure on the Load-Carrying Capacity of the Oil Film Between Gear-Teeth,” J. Inst. Pet., 38(344–345), pp. 646–672.
Grunberg, L. , and Nissan, A. H. , 1949, “ Mixture Law for Viscosity,” Nature, 164(4175), pp. 799–800. [CrossRef] [PubMed]
Bair, S. , and Casalini, R. , 2008, “ A Scaling Parameter and Function for the Accurate Correlation of Viscosity With Temperature and Pressure Across Eight Orders of Magnitude of Viscosity,” ASME J. Tribol., 130(4), p. 041802. [CrossRef]
Hayward, A. T. J. , 1971, “ How to Measure the Isothermal Compressibility of Liquids Accurately,” J. Phys. D: Appl. Phys., 4(7), pp. 938–950. [CrossRef]

Figures

Grahic Jump Location
Fig. 1

The relative volume of the oil, RL68H, and the fit to the Tait EoS

Grahic Jump Location
Fig. 2

The relative volume of RL68H + 9.2 wt.% R134a compared with the Tait EoS for the neat oil

Grahic Jump Location
Fig. 3

The Grunberg–Nissan mixing law fitted to the data points by adjusting g and adjusting m to the values given in the text

Grahic Jump Location
Fig. 4

Master curve derived from the measured relative volumes of the oil/refrigerant mixture in Table 2

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In