Browse by Author "Chato, J.C."

  • Kenny, P.J.; Chato, J.C.; Dobson, M.K.; Wattelet, J.P.; Gaibel, J.A.; Ponchner, M.; Shimon, R.L.; Villaneuva, T.C.; Rhines, N.L.; Sweeney, K.A.; Allen, D.G.; Hershberger, T.T. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 1994-07)
    This experimental study examined the local heat transfer coefficients and frictional pressure gradients of a ternary zeotropic refrigerant mixture, R-32/R-125/R-134a (23%/25%/52%) condensing in a smooth, horizontal tube. ...
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  • Sweeney, K.A.; Chato, J.C.; Ponchner, M.; Rhines, N.L. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 1995-10)
    The effects of an ester oil, in concentrations up to 5% by mass, on the behavior of R -134a condensing in a microfinned tube with an 18° helix angle were studied experimentally. The flow patterns were only minimally ...
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  • Wattelet, J.P.; Chato, J.C.; Souza, A.L.; Christoffersen, B.R. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 1993-05)
    Experimental heat transfer coefficients for R-134a, MP-39, and R-12 are reported herein. Tests were conducted using a single-tube evaporator test facility. The test section used was a 2.43 m (8-foot) long, 7.04 mm ...
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  • Dobson, M.K.; Chato, J.C.; Hinde, D.K.; Wang, S.P. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 1993-05)
    Experimental and analytical work has been performed on local heat transfer for intube condensation of pure R-134a and R-12. The data were taken in a 4.57 mm (0.18 in) ill smooth copper tube of 2.90 m (9.5 ft) length. The ...
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  • Monroe, C.A.; Newell, T.A.; Chato, J.C. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 2003-04)
    Pressure drop and heat transfer measurements were taken for smooth and internally enhanced aluminum microchannels using pure R134a. Adiabatic, evaporation, and condensation tests were conducted in the horizontally-oriented ...
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  • Crompton, J.A.; Newell, T.A.; Chato, J.C. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 2004-05)
    Often in air conditioning and refrigeration vapor compression systems the working fluid is mixed with lubricating oil, which flows through the system as it operates. The effects of this oil in the system include the possible ...
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  • Sweeney, K.A.; Chato, J.C. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 1996-05)
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  • Graham, D.M.; Chato, J.C.; Newell, T.A. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 1997-03)
    R134a condensation experiments have been petfonned over a mass flux range of 75 to 450 kg/m2-s (55 to 330 klbm/ft2-hr) in an 8.91 rom (0.351") inside diameter, axially grooved, microfin tube. At 75 kg/m2-s (55 klbm/ft2-hr), ...
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  • Dobson, M.K.; Chato, J.C.; Wang, S.P.; Hinde, D.K.; Gaibel, J.A. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 1993-06)
    Condensation heat transfer data are reported for R-22 and two potential replacements: R-134a, and a 60%/40%, azeotropic mixture of R-32 and R-125. All condensation data were collected in an 0.18" ID (4.572 mm), smooth ...
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  • Wattelet, J.P.; Chato, J.C.; Souza, A.L.; Christoffersen, B.R. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 1993-06)
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  • Jassim, E.W.; Newell, T.A.; Chato, J.C. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 2001-07)
    Adiabatic pressure drop and flow visualization in chevron plate, 1:1 aspect ratio bumpy plate, and 2:1 aspect ratio bumpy plate heat exchangers were investigated for vertical upward flow with R134a. Qualities ranging from ...
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  • Piggott, W.T., III; Newell, T.A.; Chato, J.C. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 2001-12)
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  • Yashar, D.A.; Wilson, M.J.; Kopke, H.R.; Graham, D.M.; Chato, J.C.; Newell, T.A. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 1999-08)
    A series of evaporation and condensation experiments have been performed on horizontal microfin tubes with refrigerants R134a and R410A. Mass flux varied from 75 kg/m2-s to 700 kglm2 -s and average test section quality ...
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  • Graham, D.M.; Kopke, H.R.; Wilson, M.J.; Yashar, D.A.; Chato, J.C.; Newell, T.A. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 1999-01)
    Refrigerants R134a and R410A have been used for void fraction measurements in smooth horizontal tubes with diameters between 4mm and 7mm. Quality and mass flux were varied from 5% to 90% and 75 kglm2-s to 700 kglm2-s, ...
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  • Krueger, B.A.; Krueger, B.D.; Newell, T.A.; Chato, J.C. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 2000-12)
    A number of new alternative refrigerants have been proposed in the past several years to replace the existing refrigerants used in air-conditioning equipment. In order to study these refrigerants extensively an in-depth ...
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  • Dobson, M.K.; Wattelet, J.P.; Chato, J.C. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 1993-06)
    untranslated PDF (1MB)
  • Kirshbaum, D.J.; Chato, J.C. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 1996-06)
    A Microsoft Excel spreadsheet program developed previously at ACRC to optimize condenser size with respect to surface area has been modified. A new method of modeling pipe bends has been developed incorporating a new ...
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  • Souza, A.L.; Chato, J.C.; Jabardo, J.M.S.; Wattelet, J.P.; Panek, J.S.; Christoffersen, B.; Rhines, N. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 1992-10)
    A single tube evaporator test facility capable of measuring pressure drop and heat transfer coefficients inside horizontal tubes has been designed and developed at the Air Conditioning and Refrigeration Center at the ...
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  • Jassim, E.W.; Newell, T.A.; Chato, J.C. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 2006-08)
    The purpose of this investigation is to develop models for two-phase heat transfer, void fraction, and pressure drop, three key design parameters, in single, smooth, horizontal tubes using a common probabilistic two-phase flow ...
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  • Wang, S.P.; Chato, J.C. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 1992-08)
    The fundamental physics and application of boiling and condensation of mixtures have attracted more and more attention. In this paper, the recent research in this field is reviewed. More than one hundred papers concerned with ...
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