Pool boiling of nanofluids on rough and porous coated tubes: experimental and correlation

Archives of Thermodynamics

Janusz T. Cie?li?skiCorresponding authorGda?sk University of Technology, Faculty of Mechanical Engineering, Narutowicza 11/12, 80-233 Gda?sk, PolandEmailOther articles by this author:De Gruyter OnlineGoogle Scholar¹  Tomasz Z. KaczmarczykGda?sk University of Technology, Faculty of Mechanical Engineering, Narutowicza 11/12, 80-233 Gda?sk, PolandOther articles by this author:De Gruyter OnlineGoogle Scholar¹ 

[1]Gda?sk University of Technology, Faculty of Mechanical Engineering, Narutowicza 11/12, 80-233 Gda?sk, Poland

关键词: Keywords: Pool boiling;    Nanofluids;    Correlation equation;    Rough and porous coated tubes;   

DOI  :  10.2478/aoter-2014-0010

学科分类：能源（综合）

来源: Polska Akademia Nauk * Oddzial w Gdansku, Instytut Maszyn Przeplywowych / Polish Academy of Sciences, Institute of Fluid-Flow Machinery

【 摘 要 】

The paper deals with pool boiling of water-Al2O3 and water- Cu nanofluids on rough and porous coated horizontal tubes. Commercially available stainless steel tubes having 10 mm outside diameter and 0.6 mm wall thickness were used to fabricate the test heater. The tube surface was roughed with emery paper 360 or polished with abrasive compound. Aluminium porous coatings of 0.15 mm thick with porosity of about 40% were produced by plasma spraying. The experiments were conducted under different absolute operating pressures, i.e., 200, 100, and 10 kPa. Nanoparticles were tested at the concentration of 0.01, 0.1, and 1% by weight. Ultrasonic vibration was used in order to stabilize the dispersion of the nanoparticles. It was observed that independent of operating pressure and roughness of the stainless steel tubes addition of even small amount of nanoparticles augments heat transfer in comparison to boiling of distilled water. Contrary to rough tubes boiling heat transfer coefficient of tested nanofluids on porous coated tubes was lower compared to that for distilled water while boiling on porous coated tubes. A correlation equation for prediction of the average heat transfer coefficient during boiling of nanofluids on smooth, rough and porous coated tubes is proposed. The correlation includes all tested variables in dimensionless form and is valid for low heat flux, i.e., below 100 kW/m2.

【 授权许可】

Unknown