Effect of pressure, subcooling, and dissolved gas on pool boiling heat transfer from microporous, square pin-finned surfaces in FC-72

Abstract The present research is an experimental study of the effects of pressure, subcooling, and non-condensable gas (air) on the pool nucleate boiling heat transfer performance of microporous enhanced finned surfaces. The test surfaces, solid copper blocks with 1-cm 2 bases and 5×5 square pin-fin arrays of 2, 4 and 8 mm fin lengths, were immersed in FC-72. The test conditions included an absolute pressure range of 30–150 kPa and a subcooling range of 0 (saturation) to 50 K. Effects of these parameters on nucleate boiling and critical heat flux (CHF) were investigated. In addition, differences between pure subcooled and gas-saturated conditions as well as horizontal and vertical base orientations were also investigated. Results showed that, in general, the effects of pressure and subcooling on both nucleate boiling and CHF were consistent with previously tested flat surface results, however, subcooling was found to significantly affect the high heat flux region of the microporous finned surfaces nucleate boiling curves. The relative enhancement of CHF from increased subcooling was greater for the microporous surface than the plain surface but less than a microporous flat surface. The horizontal orientation (horizontal base/vertical fins) was found to be slightly better than the vertical orientation (vertical base/horizontal fins). Correlations for both nucleate boiling and CHF for the microporous surfaces were also developed.

[1]  S. M. You,et al.  Painting technique to enhance pool boiling heat transfer in saturated FC-72 , 1995 .

[2]  W. Hamburgen,et al.  Pool boiling enhancement techniques for water at low pressure , 1991, 1991 Proceedings, Seventh IEEE Semiconductor Thermal Measurement and Management Symposium.

[3]  W. H. McAdams,et al.  Heat Transfer at High Rates to Water with Surface Boiling , 1949 .

[4]  N. Abuaf,et al.  Pool boiling performance of finned surfaces in R-113 , 1985 .

[5]  S. M. You,et al.  Boiling heat transfer phenomena from microporous and porous surfaces in saturated FC-72 , 1997 .

[6]  S. M. You,et al.  Pool Boiling Heat Transfer From Plain and Microporous, Square Pin Finned Surfaces in Saturated FC-72 , 1999, Heat Transfer: Volume 4.

[7]  W. Rohsenow.  A Method of Correlating Heat-Transfer Data for Surface Boiling of Liquids , 1952, Journal of Fluids Engineering.

[8]  N. Zuber.  Hydrodynamic aspects of boiling heat transfer (thesis) , 1959 .

[9]  S. M. You,et al.  Enhanced boiling heat transfer from microporous surfaces: effects of a coating composition and method , 1997 .

[10]  D. Kenning.  Liquid—vapor phase-change phenomena , 1993 .

[11]  S. M. You,et al.  Boiling characteristics of cylindrical heaters in saturated, gas-saturated, and pure-subcooled FC-72 , 1997 .

[12]  S. M. You,et al.  EFFECTS OF HEATER SIZE AND ORIENTATION ON POOL BOILING HEAT TRANSFER FROM MICROPOROUS COATED SURFACES , 2001 .

[13]  Haruhiko Ohta,et al.  EFFECTS OF SYSTEM PRESSURE AND SURFACE ROUGHNESS ON NUCLEATE BOILING HEAT TRANSFER. , 1982 .

[14]  J. Lienhard,et al.  Influences of subcooling on burnout of horizontal cylindrical heaters , 1988 .

[15]  Avram Bar-Cohen,et al.  Combined Pressure and Subcooling Effects on Pool Boiling From a PPGA Chip Package , 1997 .

[17]  M. Monde,et al.  Effect of subcooling on critical heat flux during pool boiling on a horizontal heated wire , 1998 .

[18]  S. J. Kline,et al.  Describing Uncertainties in Single-Sample Experiments , 1953 .