Pool Boiling Heat Transfer of N-Pentane and Acetone on Nanostructured Surfaces by Electrophoretic Deposition

2018 ◽  
Author(s):  
Zan Wu ◽  
Anh Duc Pham ◽  
Zhen Cao ◽  
Cathrine Alber ◽  
Peter Falkman ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Electrophoretic Deposition ◽  
Boiling Heat Transfer ◽  
Smooth Surface ◽  
Pool Boiling ◽  
Nucleation Site ◽  
Working Fluids ◽  
Pool Boiling Heat Transfer ◽  
Nanostructured Surfaces ◽  
Coated Surfaces

This work aims to investigate pool boiling heat transfer enhancement by using nanostructured surfaces. Two types of nanostructured surfaces were employed, gold nanoparticle-coated surfaces and alumina nanoparticle-coated surfaces. The nanostructured surfaces were fabricated by an electrophoretic deposition technique, depositing nanoparticles in a nanofluid onto smooth copper surfaces under an electric field. N-pentane and acetone were tested as working fluids. Compared to the smooth surface, the pool boiling heat transfer coefficient has been increased by 80% for n-pentane and acetone. Possible mechanisms for the enhancement in heat transfer are qualitatively provided. The increase in active nucleation site density due to multiple micro/nanopores on nanoparticle-coated surfaces is likely the main contributor. The critical heat flux on nanostructured surfaces are approximately the same as that on the smooth surface because both smooth and modified surfaces show similar wickability for the two working fluids.

Pool Boiling Heat Transfer Enhancement of Water by Gold Nanoparticles With an Electrophoretic Deposition Method

2018 ◽  
Author(s):  
Zhen Cao ◽  
Anh Duc Pham ◽  
Zan Wu ◽  
Tautgirdas Ruzgas ◽  
Cathrine Alber ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Gold Nanoparticles ◽  
Electrophoretic Deposition ◽  
Boiling Heat Transfer ◽  
Pool Boiling ◽  
Electrical Potential ◽  
Heat Fluxes ◽  
Deposition Method ◽  
Pool Boiling Heat Transfer ◽  
Modified Surfaces

Saturated pool boiling heat transfer of water is investigated experimentally on copper surfaces with nanoparticle coatings at atmospheric pressure. The coatings are generated by an electrophoretic deposition method (EPD). Three modified surfaces are prepared with gold nanoparticles of 0.20 mg, 0.25 mg and 0.30 mg, respectively. During the deposition, ethanol works as the solvent while the electrical potential and deposition time are controlled as 9.5 V and 30 min, respectively. The experimental results show that heat transfer coefficients (HTC) and critical heat fluxes (CHF) are enhanced on the modified surfaces. HTC increases with decreasing thickness of the coating, while CHF increases with increasing thickness of the coating. CHFs of EPD-0.20 mg, EPD-0.25 mg and EPD-0.30 mg are 93 W/cm2, 123 W/cm2 and 142 W/cm2, respectively, which are increased by 7%, 41% and 63% compared with the smooth surface. EPD-0.20 mg performs the best on heat transfer, with a maximum enhancement of around 60%. At the end, a brief review about mechanistic models of heat transfer at low and moderate heat fluxes is provided, based on which, the reasons why heat transfer is enhanced are discussed.

A Systematic Study of Pool Boiling Heat Transfer on Multiscale Structured Surfaces

2014 ◽  
Author(s):  
Russell P. Rioux ◽  
Eric C. Nolan ◽  
Calvin H. Li
Keyword(s):  
Heat Transfer ◽  
Boiling Heat Transfer ◽  
Multiple Scales ◽  
Pool Boiling ◽  
Theoretical Models ◽  
Sintering Process ◽  
Structured Surfaces ◽  
Pool Boiling Heat Transfer ◽  
Nanostructured Surfaces ◽  
Modified Surfaces

A study has been conducted to examine the effects of macroscale, microscale, and nanoscale surface modifications in water pool boiling heat transfer and to determine the effects of combining the multiple scales. Nanostructured surfaces were created by acid etching, while microscale and macroscale surfaces were manufactured through a sintering process. Six structures were studied as individual and/or collectively integrated surfaces: polished plain, flat nanostructured, flat porous, modulated porous, nanostructured flat porous, and nanostructured modulated porous. Boiling performance was measured in terms of critical heat flux (CHF) and heat transfer coefficient (HTC). Both HTC and CHF have been greatly improved on all modified surfaces compared to the polished baseline. The CHF and HTC of the hybrid multiscale modulated porous surface have achieved the most significant improvements of 350% and 200% over the polished plain surface, respectively. Nanoscale, microscale, and macroscale integrated surfaces have been proven to have the most significant improvements on HTC and CHF. Experimental results were compared to the predictions of a variety of theoretical models with an attempt to evaluate both microscale and nanoscale models. It was concluded that models for both microscale and nanoscale structured surfaces needed to be further developed to be able to have good quantitative predictions of CHFs on structured surfaces.

Nucleate Boiling on Biotemplated Nanostructured Surfaces

2012 ◽  
Author(s):  
Md. Mahamudur Rahman ◽  
Stephen M. King ◽  
Emre Olceroglu ◽  
Matthew McCarthy
Keyword(s):  
Heat Transfer ◽  
Self Assembly ◽  
Boiling Heat Transfer ◽  
Pool Boiling ◽  
Nucleate Boiling ◽  
Pool Boiling Heat Transfer ◽  
Nanostructured Surfaces ◽  
Transfer Capability ◽  
Good Agreement

The fabrication and characterization of biotemplated nanostructured surfaces for enhanced pool boiling heat transfer is reported. By introducing micro/nano-porosity and surface roughness at the liquid-vapor interface, significant enhancement in surface heat transfer capability can be achieved during nucleate boiling. This work uses the self-assembly and mineralization of the Tobacco mosaic virus (TMV) to create superhydrophilic (∼9°), superhydrophobic (∼163°), and mixed hydrophilic-hydrophobic (∼70°) surfaces to investigate the effects of surface wettability and heterogeneity on boiling heat transfer performance. Pool boiling results showing CHF and HTC values for nickel-coated TMV, Teflon-coated TMV, mixed nickel + Teflon coated TMV, flat silicon, and flat Teflon are reported. The mixed surfaces demonstrate a CHF enhancement of ∼ 70% compared to flat silicon and ∼140% compared to flat Teflon. The results are in good agreement with the literature and will guide the design of optimized surfaces for further enhancement. This work demonstrates the feasibility of enhancing pool boiling heat transfer using TMV based nanostructured coatings.

Enhancement of pool-boiling heat transfer using nanostructured surfaces on aluminum and copper

2010 ◽  
Vol 53 (15-16) ◽  
pp. 3357-3365 ◽  
Author(s):  
Terry J. Hendricks ◽  
Shankar Krishnan ◽  
Changho Choi ◽  
Chih-Hung Chang ◽  
Brian Paul
Keyword(s):  
Heat Transfer ◽  
Boiling Heat Transfer ◽  
Pool Boiling ◽  
Pool Boiling Heat Transfer ◽  
Nanostructured Surfaces

scholarly journals Enhancement of the pool boiling heat transfer coefficient using the gas injection into the water

2012 ◽  
Vol 14 (4) ◽  
pp. 100-109 ◽  
Author(s):  
M.M. Sarafraz ◽  
S.M. Peyghambarzadeh ◽  
S.A. Alavi Fazel
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Boiling Heat Transfer ◽  
Pool Boiling ◽  
Nucleation Site ◽  
Pool Boiling Heat Transfer ◽  
Site Density ◽  
Boiling Heat Transfer Coefficient ◽  
Nucleation Site Density

Abstract In this paper, a new method for enhancing the pool boiling heat transfer coefficient of pure liquid, based on the gas injection through the liquids has been introduced. Hence, the effect of gas dissolved in a stagnant liquid on pool boiling heat transfer coefficient, nucleation site density, and bubble departure diameter has experimentally been investigated for different mole fractions of SO2 and various heat fluxes up to 114 kW/ m2. The presence of SO2 in captured vapor inside the bubbles, particularly around the heat transfer surface increases the pool boiling heat transfer coefficient. The available predicted correlations are unable to obtain the reasonable values for pool boiling heat transfer coefficient in this particular case. Therefore, to predict the pool boiling heat transfer coefficient accurately, a new modified correlation based on Stephan-Körner relation has been proposed. Also, during the experiments, it is found that nucleation site density is a strictly exponential function of heat flux. Accordingly, a new correlation has been obtained to predict the nucleation site density. The major application of the nucleation site density is in the estimating of mean bubble diameters as well as local agitation due to the rate of bubble frequency.

Sign in / Sign up

Export Citation Format

Share Document