Enhanced boiling heat transfer by gradient porous metals in saturated pure water and surfactant solutions

2016 ◽  
Vol 100 ◽  
pp. 68-77 ◽  
Author(s):  
Z.G. Xu ◽  
C.Y. Zhao
Author(s):  
Birce Dikici ◽  
Basim Q. A. Al-Sukaini

In this study, nucleate pool boiling of surfactant solutions are investigated. The surfactants chosen for the study are an ionic sodium lauryl sulfate (SLS), nonionic ECOSURF™ EH-14, and nonionic ECOSURF™ SA-9. It is observed that adding a small amount of surfactant alters the water boiling phenomenon considerably. Boiling curves for different concentrations are shifted to the left. The wall temperature dropped with an increase in the concentration of aqueous surfactant solutions. Also, it is found that the boiling heat transfer enhancement of SLS is higher than that of EH-14 and SA-9 compared to water. Boiling heat transfer coefficient (h) enhancements compared to water are 46%, 30%, and 21%. (for SLS, for EH-14 and for SA-9 respectively) Boiling visualization shows that boiling with surfactant solutions compared with that in pure water is more vigorous. Bubbles are smaller, activate continuously, and collapse quickly. Also, the bubble departure frequency is observed to be higher than that of pure water. Results prove that there is an important possibility to enhance the boiling application processes by environmentally friendly EH-14, and SA-9 additives. Experimentation can be extended for searching other surfactants in order to find their most efficient quantity in water for boiling heat transfer.


2009 ◽  
Vol 52 (25-26) ◽  
pp. 5802-5813 ◽  
Author(s):  
John D. Schwarzkopf ◽  
Steven G. Penoncello ◽  
Prashanta Dutta

Author(s):  
Xiaopeng Qu ◽  
Huihe Qiu

The effect of acoustic field on the dynamics of micro thermal bubble is investigated in this paper. The micro thermal bubbles were generated by a micro heater which was fabricated by standard Micro-Electro-Mechanical-System (MEMS) technology and integrated into a mini chamber. The acoustic field formed in the mini chamber was generated by a piezoelectric plate which was adhered on the top side of the chamber’s wall. The dynamics and related heat transfer induced by the micro heater generated vapor bubble with and without the existing of acoustic field were characterized by a high speed photograph system and a micro temperature sensor. Through the experiments, it was found that in two different conditions, the temperature changing induced by the micro heater generated vapor bubble was significantly different. From the analysis of the high speed photograph results, the acoustic force induced micro thermal bubble movements, such as forcibly removing, collapsing and sweeping, were the main effects of acoustic enhanced boiling heat transfer. The experimental results and theoretical analysis were helpful for understanding of the mechanisms of acoustic enhanced boiling heat transfer and development of novel micro cooling devices.


Nano Letters ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 6392-6396 ◽  
Author(s):  
Sangwoo Shin ◽  
Geehong Choi ◽  
Bhargav Rallabandi ◽  
Donghwi Lee ◽  
Dong Il Shim ◽  
...  

2012 ◽  
Vol 24 (5) ◽  
pp. 052105 ◽  
Author(s):  
Zachary Douglas ◽  
Thomas R. Boziuk ◽  
Marc K. Smith ◽  
Ari Glezer

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