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.

Pool Boiling Heat Transfer with Nanotube Arrays Surface on Titanium

2012 ◽  
Vol 550-553 ◽  
pp. 2913-2916 ◽  
Author(s):  
Jin Liang Tao ◽  
Xin Liang Wang ◽  
Pei Hua Shi ◽  
Xiao Ping Shi
Keyword(s):  
Heat Transfer ◽  
Boiling Heat Transfer ◽  
Heat Transfer Performance ◽  
Pool Boiling ◽  
Nucleate Boiling ◽  
Test Fluid ◽  
Porous Coating ◽  
Pool Boiling Heat Transfer ◽  
Nucleate Boiling Heat Transfer ◽  
Boiling Heat Transfer Coefficient

In this paper, a new porous coating was formed directly on the surface of titanium metal via anodic oxidation. And by the SEM, the morphology of the coating, which is composed of well-ordered perpendicular nanotubes, was characterized. Moreover, taking deionized water as the test fluid, a visualization study of the coating on its pool boiling heat transfer performance was made. The results demonstrated that compared with the smooth surface, the nucleate boiling heat transfer coefficient can increase 3 times while the nucleate boiling super heat was reduced 30%.

Nucleate Pool Boiling Heat Transfer Coefficients of Distilled Water (H2O) and R-134a/Oil Mixtures From Rib-Roughened Surfaces

1997 ◽  
Vol 119 (1) ◽  
pp. 142-151 ◽  
Author(s):  
Shou-Shing Hsieh ◽  
Chun-Jen Weng
Keyword(s):  
Heat Transfer ◽  
Boiling Heat Transfer ◽  
Pool Boiling ◽  
Distilled Water ◽  
Transfer Coefficients ◽  
Pool Boiling Heat Transfer ◽  
Heat Transfer Coefficients ◽  
Oil Mixtures ◽  
R 134A ◽  
Rib Roughened

Measurements of pool-boiling heat transfer coefficients in distilled water and R-134a/oil mixtures with up to 10 percent (by weight) miscible EMKARATE RL refrigeration lubricant oil are extensively studied for a smooth tube and four rib-roughened tubes (rib pitch 39.4 mm, rib height 4 mm, rib width 15 mm, number of rib element 8, rib angle 30 deg–90 deg). Boiling data of pure refrigerants and oil mixtures, as well as the influences of heat flux level on heat transfer coefficient, are presented and discussed. A correlation is developed for predicting the heat transfer coefficient for both pure refrigerants and refrigerant-oil mixtures. Moreover, boiling visualizations were made to broaden our fundamental understanding of the pool boiling heat transfer mechanism for rib roughened surfaces with pure refrigerants and refrigerant-oil mixtures.

scholarly journals Effect of Uniformly and Nonuniformly Coated Al2O3 Nanoparticles over Glass Tube Heater on Pool Boiling

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Nitin Doifode ◽  
Sameer Gajghate ◽  
Abdul Najim ◽  
Anil Acharya ◽  
Ashok Pise
Keyword(s):  
Heat Transfer ◽  
Boiling Heat Transfer ◽  
High Speed ◽  
Pool Boiling ◽  
Glass Tube ◽  
Al2o3 Nanoparticles ◽  
High Speed Camera ◽  
Coated Nanoparticles ◽  
Nucleation Sites ◽  
Coated Surface

Effect of uniformly and nonuniformly coated Al2O3 nanoparticles over plain glass tube heater on pool boiling heat transfer was studied experimentally. A borosilicate glass tube coated with Al2O3 nanoparticle was used as test heater. The boiling behaviour was studied by using high speed camera. Result obtained for pool boiling shows enhancement in heat transfer for nanoparticle coated surface heater and compared with plain glass tube heater. Also heat transfer coefficient for nonuniformly coated nanoparticles was studied and compared with uniformly coated and plain glass tube. Coating effect of nanoparticles over glass tube increases its surface roughness and thereby creates more nucleation sites.

The Latest Review of Low GWP (<100) HFO Refrigerants and Studies on the Pool Boiling Heat Transfer

2016 ◽  
Vol 24 (04) ◽  
pp. 1630009 ◽  
Author(s):  
Dong Ho Kim ◽  
Ho Won Byun ◽  
Seok Ho Yoon ◽  
Chan Ho Song ◽  
Kong Hoon Lee ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Boiling Heat Transfer ◽  
Pool Boiling ◽  
Field Testing ◽  
Montreal Protocol ◽  
Limited Information ◽  
Pool Boiling Heat Transfer ◽  
Cycle Simulation ◽  
Core Technology ◽  
Boiling Heat Transfer Coefficient

The low GWP refrigerants attract a great attention due to various regulations such as Montreal protocol amendment and F-gas regulation. The amendment of Montreal protocol proposes to reduce the HFCs consumption by 85% until 2035 and F-gas legislation will reduce the HFCs consumption by 79% until 2030. In 2010, US DOE launched the low GWP refrigerant project which covers the lifecycle climate performance modeling, experimental evaluation and field testing. In 2015, Korea launched the project to develop the core technology of refrigeration system for low GWP ([Formula: see text]100) refrigerants application. Since the project limited the GWP value less than 100, the applicable candidates (except for natural working fluids) are restricted about five refrigerants including R-1234yf, R-1234ze-(E), R444A, R-1233zd(E) and R-1336mzz. In the literature, to the best of the author’s knowledge, there is very limited information for pool boiling studies except R-1234yf. In present work, the cycle simulation and the prediction of pool boiling heat transfer coefficient for each refrigerant has been conducted. And the literature review of pool boiling for the refrigerants has been performed.

scholarly journals Quantitative Evaluation of the Dependence of Pool Boiling Heat Transfer Enhancement on Sintered Particle Coating Characteristics

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Suchismita Sarangi ◽  
Justin A. Weibel ◽  
Suresh V. Garimella
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Boiling Heat Transfer ◽  
Pool Boiling ◽  
Transfer Enhancement ◽  
Pool Boiling Heat Transfer ◽  
Boiling Heat Transfer Coefficient ◽  
Coating Characteristics

Immersion cooling strategies often employ surface enhancements to improve the pool boiling heat transfer performance. Sintered particle/powder coatings have been commonly used on smooth surfaces to reduce the wall superheat and increase the critical heat flux (CHF). However, there is no unified understanding of the role of coating characteristics on pool boiling heat transfer enhancement. The morphology and size of the particles affect the pore geometry, permeability, thermal conductivity, and other characteristics of the sintered coating. In turn, these characteristics impact the heat transfer coefficient and CHF during boiling. In this study, pool boiling of FC-72 is experimentally investigated using copper surfaces coated with a layer of sintered copper particles of irregular and spherical morphologies for a range of porosities (∼40–80%). Particles of the same effective diameter (90–106 μm) are sintered to yield identical coating thicknesses (∼4 particle diameters). The porous structure formed by sintering is characterized using microcomputed tomography (μ-CT) scanning to study the geometric and effective thermophysical properties of the coatings. The boiling performance of the porous coatings is analyzed. Coating characteristics that influence the boiling heat transfer coefficient and CHF are identified and their relative strength of dependence analyzed using regression analysis. Irregular particles yield higher heat transfer coefficients compared to spherical particles at similar porosity. The coating porosity, pore diameter, unit necking area, unit interfacial area, effective thermal conductivity, and effective permeability are observed to be the most critical coating properties affecting the boiling heat transfer coefficient and CHF.

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