Experimental and Numerical Investigation of Pool Boiling Heat Transfer over Different Thickness of Graphene-Poly(3,4-Ethylenedioxythiophene):Poly(Styrenesulfonate) Layers on Copper Heater Surface

The present study involves the use of dip nanocoating, one of the passive techniques by the modification of the heater surface to understand the behavior of pool boiling heat transfer characteristics at atmospheric pressure using deionized water and graphene-poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) as a working fluid and coating material. The copper specimen is coated with the mentioned material with varying thickness from 96.53 to 399.22 nm using the dip coating method. Surface characterization revealed the presence of graphene and poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) polymer over the copper specimen. The coating thickness, surface roughness, and contact angle conditions as input values are considered for numerical simulation, and a comparative study has been carried out with the experimental results. The plain copper surface result is compared with the Rohsenow correlation and found to be an acceptable level. The maximum augmentation in heat transfer coefficient is observed for the highest coating thickness and surface roughness at 52.6% and 123.3% for both evaluation method cases compared to the plain copper surface. The boiling outcomes are also confirmed with the bubble dynamics through both the investigations and the obtained bubble results satisfied with the best case result for augmentation.