Forced Convection Film Boiling Heat Transfer From Single Horizontal Cylinders in Saturated and Subcooled Liquids: Part 1 — Experimental Data and Its Correlation for Saturated Liquids

2008 ◽  
Author(s):  
Qiusheng Liu ◽  
Katsuya Fukuda
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Forced Convection ◽  
Boiling Heat Transfer ◽  
Horizontal Cylinder ◽  
Film Boiling ◽  
Two Phase ◽  
Saturated Water ◽  
Horizontal Cylinders ◽  
Flow Velocities

Forced convection film boiling heat transfer on a horizontal cylinder in saturated water and Freon-113 flowing upward perpendicular to the cylinder was measured for the flow velocities ranging from zero to 1 m/s at the system pressures ranging from 100 to 500 kPa: the platinum cylinders with the diameters ranging from 0.7 to 5 mm were used as the test cylinder heaters. The existing correlation for forced convection film boiling heat transfer given by Bromley et al. could not well describe the experimental data obtained, especially those for the higher pressures. The forced convection film boiling heat transfer correlation including the radiation contribution from the cylinders with various diameters for saturation conditions was developed based on forced convection two-phase laminar boundary layer film boiling model and the experimental data obtained. The experimental data agreed with the corresponding values derived from the correlation within ±15% for the flow velocities below 0.7 m/s, and within −30% to +15% for higher flow velocities. It was confirmed that the experimental data obtained by Bromley et al. for the horizontal carbon cylinders with the diameters ranging from 9.83 to 16.2 mm and with the significant radiation effect from the cylinder surfaces in various liquids for the various flow velocities up to 4.4 m/s at an atmospheric pressure agreed with the corresponding values derived from the new correlation within ±20%.

Forced Convection Film Boiling Heat Transfer From Single Horizontal Cylinders in Saturated and Subcooled Liquids: Part 2—Experimental Data for Subcooled Liquids and Its Correlation

2009 ◽  
Author(s):  
Qiusheng Liu ◽  
Masahiro Shiotsu ◽  
Akira Sakurai ◽  
Katsuya Fukuda
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Forced Convection ◽  
Boiling Heat Transfer ◽  
Film Boiling ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
System Pressure ◽  
Horizontal Cylinders ◽  
Flow Velocities

Forced convection film boiling heat transfer from a horizontal cylinder in water and Freon-113 flowing upward perpendicular to the cylinder under subcooled conditions was measured for the flow velocities from 0 to 1 m/s at the system pressures ranging from 100 to 500 kPa: the platinum horizontal cylinders with diameters ranging from 0.7 to 5 mm were used as the test heaters. The film boiling heat transfer coefficients were obtained for the surface superheats from about 800 K for water and from about 400 K for Freon-113 down to minimum film boiling surface superheats. These heat transfer coefficients increase with the increase in flow velocity, liquid subcooling, system pressure, and with the decrease in cylinder diameter. A correlation for subcooled forced convection film boiling heat transfer was presented, which can describe the experimental data obtained within ±20% for the flow velocities below 0.7 m/s, and within −30% to +20% for the higher flow velocities. The correlation also predicted well the data by Shigechi (1983), Motte and Bromley (1957), and Sankaran and Witte (1990) obtained for the larger diameter cylinders and higher flow velocities in various liquids at the pressures of near atmospheric. The Shigechi’s data were in the range from about −20% to +15%, the data of Motte and Bromley were about ±30%, and the data of Sankaran and Witte were within +20% of the curves given by the corresponding predicted values.

A General Correlation for Pool Film Boiling Heat Transfer From a Horizontal Cylinder to Subcooled Liquid: Part 2—Experimental Data for Various Liquids and Its Correlation

1990 ◽  
Vol 112 (2) ◽  
pp. 441-450 ◽  
Author(s):  
A. Sakurai ◽  
M. Shiotsu ◽  
K. Hata
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Analytical Solution ◽  
Boiling Heat Transfer ◽  
Radiation Effects ◽  
Approximate Analytical Solution ◽  
Horizontal Cylinder ◽  
Film Boiling ◽  
System Pressure ◽  
Horizontal Cylinders

Experimental data of pool film boiling heat transfer from horizontal cylinders in various liquids such as water, ethanol, isopropanol, Freon-113, Freon-11, liquid nitrogen, and liquid argon for wide ranges of system pressure, liquid subcooling, surface superheat and cylinder diameter are reported. These experimental data are compared with a rigorous numerical solution and an approximate analytical solution derived from a theoretical model based on laminar boundary layer theory for pool film boiling heat transfer from horizontal cylinders including the effects of liquid subcooling and radiation from the cylinder. A new correlation was developed by slightly modifying the approximate analytical solution to agree better with the experimental data. The values calculated from the correlation agree with the authors’ data within ± 10 percent, and also with other researchers’ data for various liquids including those with large radiation effects, though these other data were obtained mainly under saturated conditions at atmospheric pressure.

scholarly journals ELETRIC FIELD ENHANCEMENT AND DETERIORATION OF BOILING HEAT TRANSFER AND CRITICAL HEAT FLUX IN DIELECTRIC FLUIDS

2001 ◽  
Vol 1 (1) ◽  
pp. 32
Author(s):  
P. M. Carrica ◽  
V. Masson
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Critical Heat Flux ◽  
Electric Fields ◽  
Boiling Heat Transfer ◽  
Nucleate Boiling ◽  
Film Boiling ◽  
Two Phase ◽  
Boiling Regime ◽  
Dielectric Fluids

We present the results of an experimental study of the effects of externally imposed electric fields on boiling heat transfer and critical heat flux (CHF) in dielectric fluids. The study comprises the analysis of geometries that, under the effects of electric fields, cause the bubbles either to be pushed toward the heater or away from it. A local phase detection probe was used to measure the void fraction and the interfacial impact rate near the heater. It was found that the critical heat flux can be either augmented or reduced with the application of an electric field, depending on the direction of . In addition, the heat transfer can be slightly enhanced or degraded depending on the heat flux. The study of the two-phase flow in nucleate boiling, only for the case of favorable dielectrophoretic forces, reveals that the application of an electric field reduces the bubble detection time and increases the detachment frequency. It also shows that the two-phase flow characteristics of the second film boiling regime resemble more a nucleate boiling regime than a film boiling regime.

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