Critical heat flux measurements in a round tube for CFCs and CFC alternatives

Abstract Critical heat flux (CHF) measurements have been conducted for HFC-134a, HCFC-123, HCFC-22, CFC-12 and CFC-11 in a multi-fluid loop. The test pressures are up to 2 MPa (corresponding to water equivalent pressure of 7–10 MPa) and mass fluxes from 1000 to 4000 kg m−2 s−1. The heated length is adjustable from 0.5 to 1 m, the I.D. of the tubular test section is 4.2 mm, and the critical quality varies from 0.07 to 0.6. The parametric trends of test results are examined and the test results show good agreement with existing CHF prediction methods. It also provides confirmation that CFC alternatives such as HFC-134a, HCFC-123 and HCFC-22 can be used with confidence as reliable CHF modelling fluids.

[1]  Bassam Philip Kiameh.  Prediction of critical heat flux (CHF) for non-aqueous fluids in forced convective boiling , 1986 .

[2]  Y. Katto.  Prediction of critical heat flux of subcooled flow boiling in round tubes , 1990 .

[3]  J. Weisman,et al.  Prediction of critical heat flux in flow boiling at low qualities , 1983 .

[4]  M. Mohammed Shah,et al.  A generalized graphical method for predicting chf in uniformly heated vertical tubes , 1979 .

[5]  D. C. Groeneveld,et al.  Evaluation of thermophysical properties of Freon-22 , 1993 .

[6]  Y. Katto.  A physical approach to critical heat flux of subcooled flow boiling in round tubes , 1990 .

[7]  C. Lee,et al.  A mechanistic critical heat flux model for subcooled flow boiling based on local bulk flow conditions , 1988 .

[8]  Geoffrey F. Hewitt,et al.  THE CALCULATION OF CRITICAL HEAT FLUX IN FORCED CONVECTION BOILING , 1974 .

[9]  S. Y. Ahmad.  Fluid to fluid modeling of critical heat flux: A compensated distortion model , 1973 .

[10]  Y. L. Wong,et al.  Generalized thermodynamic and transport properties evaluation for nonpolar fluids , 1990 .

[11]  Y. Katto,et al.  A prediction model of subcooled water flow boiling CHF for pressure in the range 0.1–20 MPa , 1992 .

[12]  D. Groeneveld,et al.  1986 AECL-UO Critical Heat Flux Lookup Table , 1986 .

[13]  J. Gallagher,et al.  Measurement and formulation of the thermodynamic properties of refrigerants 134a (1,1,1,2 tetrafluoroethane) and 123 (1,1 dichloro 2,2,2 trifluoroethane) | NIST , 1989 .

[14]  P. B. Whalley,et al.  THE CALCULATION OF CRITICAL HEAT FLUX IN COMPLEX SITUATIONS USING AN ANNULAR FLOW MODEL , 1978 .

[15]  F. P. Lantsman,et al.  A PECULIAR TYPE OF BURNOUT IN EVAPORATIVE TUBES , 1970 .

[16]  M. Shah.  Improved general correlation for critical heat flux during upflow in uniformly heated vertical tubes , 1987 .

[17]  Y. Katto,et al.  An improved version of the generalized correlation of critical heat flux for the forced convective boiling in uniformly heated vertical tubes , 1984 .

[18]  Koichi Watanabe.  Current Status of Thermophysical Properties Research on CFC Alternatives , 1990 .

[19]  A. Kumagai,et al.  Viscosity of saturated liquid fluorocarbon refrigerants from 273 to 353 K , 1991 .