Effect of Nanoparticle Type and Surfactant on Heat Transfer Enhancement in Spray Cooling

• Published in: Journal of thermal science Vol. 29; no. 3; pp. 708 - 717
• Main Authors: Wang, Bingxing, Liu, Zhixue, Zhang, Bo, Xia, Yue, Wang, Zhaodong, Wang, Guodong
• Format: Journal Article
• Language: English
• Published: Heidelberg Science Press 01.06.2020; Springer Nature B.V
• Subjects: Aluminum oxide; Classical and Continuum Physics; Contact angle; Cooling systems; Engineering Fluid Dynamics; Engineering Thermodynamics; Heat and Mass Transfer; Heat flux; Heat transfer; Nanofluids; Nanoparticles; Physics; Physics and Astronomy; Spray cooling; Surface tension; Surfactants; Wetting; spray cooling; wettability; heat flux; nanofluids; surfactant
• ISSN: 1003-2169; 1993-033X
• DOI: 10.1007/s11630-020-1212-7

In this study, the heat transfer characteristics of nanofluids used in spray cooling systems were examined. Three nanofluids, i.e., Cu, CuO, and Al 2 O 3 , respectively, with volume fractions ranging from 0.1% to 0.5%, as well as different volume fractions of a surfactant Tween 20, were used. In addition, their contact angles were measured to examine the heat-transfer characteristics. Under the same experimental conditions, with the increase in the volume fraction of the Cu nanoparticles from 0.1% to 0.5%, the maximum heat flux q max increased from 3.36 MW/m 2 to 3.48 MW/m 2 from the impinging central point to r = 30 mm ( r is the distance from the impingement point), and the corresponding temperature of q max increased from 400°C to 420°C. Results revealed that with increasing Tween 20 concentrations, the contact angle decreased because of the decrease in the surface tension of nanofluids and improvement of the wetting ability, and the corresponding q max increased from 3.48 MW/m 2 to 3.94 MW/m 2 at the impact central point.