Naslov
Enhancement of Heat Transfer Characteristics of Liquid Quenchants

Autori
Župan, Josip ; Filetin, Tomislav ; Žmak, Irena

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
6th International Conference on Quenching and Control of Distortion / D. Scott MacKenzie - Chicago (IL) : ASM Heat Treating Society, 2012, 519-527

ISBN
13978-1-61503-980-7

Skup
6th International Conference on Quenching and Control of Distortion

Mjesto i datum
Chicago (IL), Sjedinjene Američke Države, 09.09.2012. - 13.09.2012

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Quenching; TiO2 nanoparticles; Ultrasound

Sažetak
In order to achieve greater cooling rates CR) and shorter full-film phase of liquid quenchants, two approaches were investigated. First, an enhancement of base fluid thermal properties by addition of TiO2 nanoparticles of 50 nm average particle size. Nanofluids are colloidal suspensions of nanoparticles in base fluids. In the second testing method, cooling of the base fluids was performed in an ultrasonic bath, with frequency of 50 kHz and power of 120 W. Ultrasound allows an improvement in boiling and convective heat transfer through means of acoustic streaming. Standard liquid quenchants, water and polymer solution, and their cooling curves were measured with and without ultrasound treatment, and compared. All of the cooling curves were measured and recorded by IVF SmartQuench system using Inconel 600 probe with 12.5 mm diameter in accordance with ISO 9950 standard. Cooling rate vs. temperature and time was compared for all of the investigated media, as well as the heat transfer coefficient (HTC). The addition of TiO2 powder caused a shorter full-film phase for some nanofluids and maximum CR increase by 26 %. All experiments by ultrasound treatment of the quenchants without nanoparticles provided shorter full-film phase and an increase in maximum cooling rate by 20 %. At polymer concentrations of 30 %PAG neither the TiO2 nanoparticles, nor the application of ultrasound had any significant effect on the cooling curve.

Izvorni jezik
Engleski

Znanstvena područja
Strojarstvo

POVEZANOST RADA