Experimental investigation of critical heat flux on SiO2 thin film deposited copper substrate in DI water at atmospheric pressure

Abstract

High heat flux at low excess temperature is the prime factor in pool boiling heat transfer. One of the methods to enhance peak heat flux in nucleate boiling is surface modification. The substrate of the copper has been modified by SiO2 thin film coating. The coating was performed on the substrate at three different thicknesses 250 nm, 500 nm, and 750 nm. The thin film coating was done by sputtering technique. The water contact angle was measured for bare and SiO2 thin film coated substrates. The contact angle decreased drastically because of more nucleation sites involved for wetting the substrate. The coating characteristics reported that the wettability of the copper substrate plays an important role in the critical heat flux enhancement. The critical heat flux test was carried out for bare copper substrate and SiO2 thin film coated copper substrates. The SiO2 thin film coating exhibited superhydrophillic nature on the substrate because of greater wettability. The superhydrophillic nature of the substrate enhanced the peak heat flux significantly. Also the boiling heat transfer coefficient was improved at high heat flux in nucleate boiling regime.

Plasma deposition of a stable SiOx‐like layer on copper surface for enhanced pool boiling heat transfer performance: A combination of microstructures and wetting properties

“…Therefore, stability is one of the unique features of the SiO 2 film. Also, SiO 2 , due to its hydrophilic nature, improves the key parameters of pool boiling such as HTC and CHF, as reported in the studies of Das and Bhaumik, [ 16 ] Das et al, [ 7 ] Nithyanandam et al, [ 18 ] and the present study.…”

“…Nithyanandam et al [ 18 ] studied PBHT under the influence of a thin‐film SiO 2 deposited on a copper surface by sputtering. The coating was created on the substrate with three different thicknesses, 250, 500, and 750 nm.…”