Investigations on thermophysical properties and nucleate boiling with different surfaces using hydrazine reduced graphene oxide water nanofluids synthesis and characterization

Abstract

Nucleate boiling is an efficient method that offers two folds of Heat newlineTransfer Coefficient (HTC) than single phase heat transfer and hence, it is newlineused in chemical reactors, refrigeration cycles, re-boilers, solar collectors etc. newlineOver last two decades, numerous experimental studies have been conducted newlinewith different heating surfaces for improving HTC of different base fluids. newlineThe studies showed that contact angle and surface roughness are the major newlinefactors that affect HTC and are stretched to their limits. Also, it is observed newlinefrom literature that boiling heat transfer with enhanced/micro/nano structured newlinesurfaces is found to increase with active nucleation sites. However, the newlinepreparation of a micro/nano structure surface is a time consuming process and newlinehigher cost. Also, it is always a challenging task in getting uniform newlinemicro/nano structures. newlineAlternatively, Nanofluids prepared by dispersion of nanosized particles newlinein base fluids is a promising technology for enhancing HTC. The addition of newlinenanomaterials into base fluids increases thermal properties of nanofluids and newlinethis helps to enhance the boiling behaviour. However, the above studies used newlineonly one surface for their experimental investigations. Also, most of the newlinestudies suggested that the boiling behavior is due to surface roughness of newlineheater material and inconsistencies in the results. This is because of the newlinemethod of preparation of nanofluids and lack of dispersion stability of newlinenanofluids. Further, most of the studies used one dimensional nanomaterial newlineand hence, the present work concentrates on two dimensional nanomaterial newlinei.e. reduced graphene oxide nanomaterial (rGO). newline