Pool Boiling on Polished and Chemically Etched Stainless-Steel Surfaces

1968 ◽  
Vol 90 (2) ◽  
pp. 231-238 ◽  
Author(s):  
R. I. Vachon ◽  
G. E. Tanger ◽  
D. L. Davis ◽  
G. H. Nix
Keyword(s):  
Heat Transfer ◽  
Surface Roughness ◽  
Stainless Steel ◽  
Atmospheric Pressure ◽  
Pool Boiling ◽  
304 Stainless Steel ◽  
Distilled Water ◽  
Preparation Technique ◽  
Nucleation Sites ◽  
Steel Surfaces

This paper presents pool boiling data at atmospheric pressure for mechanically polished and chemically etched 304 stainless-steel surfaces in contact with distilled water. The surfaces were prepared by these techniques to produce variation in nucleation sites. Surface roughness was varied from 2–61 rms. The results show the changes in heat transfer with varying rms surface roughness and preparation technique. The Rohsenow pool boiling correlation was used to discuss the data.

Comparison of Gas Nucleation and Pool Boiling Site Densities

2004 ◽  
Author(s):  
Yusen Qi ◽  
James F. Klausner
Keyword(s):  
Heat Transfer ◽  
Stainless Steel ◽  
Pool Boiling ◽  
Nucleation Site ◽  
Nucleation Theory ◽  
Distilled Water ◽  
General Validity ◽  
Site Density ◽  
Steel Surfaces ◽  
Nucleation Site Density

It has been well established that the rate of heat transfer associated with boiling systems is strongly dependent on the nucleation site density. Over many years attempts have been made to predict nucleation site density in boiling systems using a variety of techniques. With the exception of specially prepared surfaces, these attempts have met with little success. This paper presents an experimental investigation of nucleation site density measured on roughly polished brass and stainless steel surfaces for gas nucleation and pool boiling over a large parameter space. The fluids used for this study, distilled water and ethanol, are moderately wetting and highly wetting, respectively. Using distilled water it has been observed that the trends of nucleation site density versus the inverse of the critical radius are similar for pool boiling and gas nucleation. The nucleation site density is higher for gas nucleation than for pool boiling. An unexpected result has been observed with ethanol as the heat transfer fluid, which casts doubt on the general validity of heterogeneous nucleation theory. Due to flooding, few sites are active on the brass surface and at most two are active on the stainless steel surface during gas nucleation experiments. However, nucleation sites readily form in large concentration on both the brass and stainless steel surfaces during pool boiling. The nucleation site densities for the rough and mirror polished brass surfaces are also compared. It shows that there is no large difference for the measured nucleation site density.

Comparison of Nucleation Site Density for Pool Boiling and Gas Nucleation

2005 ◽  
Vol 128 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Yusen Qi ◽  
James F. Klausner
Keyword(s):  
Heat Transfer ◽  
Stainless Steel ◽  
Pool Boiling ◽  
Nucleation Site ◽  
Stainless Steel Surface ◽  
Distilled Water ◽  
Site Density ◽  
Significant Difference ◽  
Steel Surfaces ◽  
Nucleation Site Density

It has been well established that the rate of heat transfer associated with boiling systems is strongly dependent on the nucleation site density. Over many years attempts have been made to predict nucleation site density in boiling systems using a variety of techniques. With the exception of specially prepared surfaces, these attempts have met with little success. This paper presents an experimental investigation of nucleation site density measured on roughly polished brass and stainless steel surfaces for gas nucleation and pool boiling over a large parameter space. A statistical model used to predict the nucleation site density in saturated pool boiling is also investigated. The fluids used for this study, distilled water and ethanol, are moderately wetting and highly wetting, respectively. Using distilled water it has been observed that the trends of nucleation site density versus the inverse of the critical radius are similar for pool boiling and gas nucleation. The nucleation site density is higher for gas nucleation than for pool boiling. An unexpected result has been observed with ethanol as the heat transfer fluid, which casts doubt on the general assumption that heterogeneous nucleation in boiling systems is exclusively seeded by vapor trapping cavities. Due to flooding, few sites are active on the brass surface and at most two are active on the stainless steel surface during gas nucleation experiments. However, nucleation sites readily form in large concentration on both the brass and stainless steel surfaces during pool boiling. The pool boiling nucleation site densities for ethanol on rough and mirror polished brass surfaces are also compared. It shows that there is not a significant difference between the measured nucleation site densities on the smooth and rough surfaces. These results suggest that, in addition to vapor trapping cavities, another mechanism must exist to seed vapor bubble growth in boiling systems.

Pool boiling performance of oxide nanofluid on a downward-facing heating surface

Kerntechnik ◽  
2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Zhibo Zhang ◽  
Huai-En Hsieh ◽  
Yuan Gao ◽  
Shiqi Wang ◽  
Jia Gao ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Surface Roughness ◽  
Stainless Steel ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Critical Heat Flux ◽  
Pool Boiling ◽  
Heating Surface ◽  
Nano Particles

Abstract In this study, the pool boiling performance of oxide nanofluid was investigated, the heating surface is a 5 × 30 mm stainless steel heating surface. Three kinds of nanofluids were selected to explore their critical heat flux (CHF) and heat transfer coefficient (HTC), which were TiO2, SiO2, Al2O3. We observed that these nanofluids enhanced CHF compared to R·O water, and Al2O3 case has the most significant enhancement (up to 66.7%), furthermore, the HTC was also enhanced. The number of bubbles in nanofluid case was relatively less than that in R·O water case, but the bubbles were much larger. The heating surface was characterized and it was found that there were nano-particles deposited, and surface roughness decreased. The wettability also decreased with the increase in CHF.

Boiling and Evaporation From Heat Pipe Wicks With Water and Acetone

1974 ◽  
Vol 96 (3) ◽  
pp. 331-337 ◽  
Author(s):  
A. Abhat ◽  
R. A. Seban
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Atmospheric Pressure ◽  
Saturated Vapor ◽  
Pool Boiling ◽  
Tube Surface ◽  
Evaporation Surface ◽  
Nucleation Sites ◽  
Boiling And Evaporation ◽  
Vertical Tubes

Heat transfer for pool boiling with flaxes in the range of 5 × 102 5 × 104 Btu/(ft2 hr) and the associated excess of wall over saturation temperatures are presented, primarily for atmospheric pressure, for vertical tubes in water, ethanol, and acetone, bare or wrapped with screen or felt metal. For the wrapped tubes, this performance is given also for evaporation into surrounding saturated vapor with the liquid being supplied by the wick: this is the significant mode in respect to heat pipe applications. For this mode maximum evaporation rates are also indicated and it is shown that this maximum can be rationalized either in terms of a partially full wick with conduction transfer to the evaporation surface or in terms of a full wick with vapor holes originating at nucleation sites on the tube surface.

scholarly journals Pool boiling of ethanol and FC-72 on open microchannel surfaces

2018 ◽  
Vol 180 ◽  
pp. 02042 ◽  
Author(s):  
Robert Kaniowski ◽  
Robert Pastuszko
Keyword(s):  
Heat Transfer ◽  
Atmospheric Pressure ◽  
Pool Boiling ◽  
Experimental Investigations ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Nucleation Sites ◽  
Open Microchannel ◽  
Acquisition Speed ◽  
Parallel Microchannels

The paper presents experimental investigations into pool boiling heat transfer for open microchannel surfaces. Parallel microchannels fabricated by machining were about 0.3 mm wide, and 0.2 to 0.5 mm deep and spaced every 0.1 mm. The experiments were carried out for ethanol, and FC-72 at atmospheric pressure. The image acquisition speed was 493 fps (at resolution 400 × 300 pixels with Photonfocus PHOT MV-D1024-160-CL camera). Visualization investigations aimed to identify nucleation sites and flow patterns and to determine the bubble departure diameter and frequency at various superheats. The primary factor in the increase of heat transfer coefficient at increasing heat flux was a growing number of active pores and increased departure frequency. Heat transfer coefficients obtained in this study were noticeably higher than those from a smooth surface.

Correlation of Subatmospheric Pressure, Saturated, Pool Boiling of Water on a Structured-Porous Surface

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Sean J. Penley ◽  
R. A. Wirtz
Keyword(s):  
Heat Transfer ◽  
Boiling Heat Transfer ◽  
Pool Boiling ◽  
Bubble Nucleation ◽  
Distilled Water ◽  
Heat Transfer Correlation ◽  
Subatmospheric Pressure ◽  
Strong Function ◽  
Nucleation Sites ◽  
Boiling Heat Transfer Coefficient

Saturated pool-boiling experiments at 1 atm and subatmospheric pressure assess the utility of fine-filament screen-laminate enhanced surfaces as effective bubble nucleation sites. Experiments were conducted on vertically oriented, multilayer laminates in saturated distilled water at pressures of 0.2–1.0 atm. The performance of 12 different copper-filament surfaces, having pore hydraulic diameters ranging from 14 μm to 172 μm, is documented. Experimental results show that boiling performance is a strong function of screen-laminate geometry. In the present work, enhancement of up to 27 times that of an unenhanced surface was obtained at a superheat of 8 K and a pressure of 0.2 atm. Dimensional analysis and multiparameter regression are used to develop a heat transfer correlation that relates the boiling heat transfer coefficient to the lamination geometry.

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