Boiling Heat Transfer Enhancement by Self‐Assembled Graphene/Silver Hybrid Film for the Thermal Management of Concentrated Photovoltaics

Abstract

Graphene nanosheets have attracted appreciable interest in heat transfer augmentation due to the unique deposition characteristics. The porous morphology of the graphene deposited on the heating surface via self‐assembly is reported to retard the transition boiling significantly. However, less attention has been paid to ameliorate the heat transfer coefficient (HTC) of graphene‐dispersed solutions. Herein, silver ions are introduced into graphene nanofluids to ameliorate its HTC. During boiling, graphene nanosheets and silver nanoparticles simultaneously deposit on the heating surface to form a well‐structured porous graphene/silver hybrid coating. The newly formed surface is characterized for surface morphology, wettability, and roughness. The new surface coating enhances the HTC by up to 109% and maintains the retarded critical heat flux of graphene‐only nanofluids. The application of the enhanced boiling heat transfer for the thermal management of concentrated photovoltaics is studied. It is demonstrated that enhanced boiling allows for cogeneration of electricity and heat from concentrated photovoltaics at approximately fourfold increased production rate while maintaining efficient, safe, and reliable operation.

Recent progress in films with nanoengineered surfaces via bubble-induced self-assembly for energy applications

“…3f). 59,67 In addition to lms with a single surface characteristic generated by the BISA of an individual nanomaterial, lms with heterogeneous structures and mixed surface characteristic can be obtained by loading various hybrid nanomaterials for the BISA. A silver/graphene hybrid surface has been formed by loading a stable silver/graphene solution as a working medium for the BISA (Fig.…”

“…82,83 A detailed summary of the generated lms with nanoengineered surfaces by the BISA of various nanomaterials and their enhancement of boiling heat transfer capacity including CHF and HTC is presented in Table 1. 43,56,61,62,[66][67][68][69][84][85][86][87][88] The boiling process is mainly related to the liquid rewetting and bubble behaviors, such as the bubble nucleation, growth and departure. Several factors that have an impact on the boiling heat transfer include the surface wettability, roughness, capillary wicking performance and bubble dynamics (Fig.…”

“…13b). 67 It is necessary to increase the overall production of the CPV system by concentrating more solar energy on the CPV cells. Heat flux and temperature, however, increase rapidly, thus decreasing the cell efficiency, and even damaging the cell under high-temperature conditions.…”

The Pool-Boiling-Induced Deposition of Nanoparticles as the Transient Game Changer—A Review

“… Positive effects of the nanofluids and nanoparticle deposition relative to water. Adapted from [ 47 ]. …”

Transformation, reaction and organization of functional nanostructures using solution-based microreactor-assisted nanomaterial deposition for solar photovoltaics

“…[25][26][27][28][29][30] There have been few works in terms of passive heat management techniques, such as metamaterials, graphene/Ag hybrid film, and SiO 2 particles, to mitigate the adverse thermal effects. [30][31][32][33] These nanostructures and nanostructured films (nanocrystalline, nanoporous, core-shell, nanocomposites, nanowires, nanorods, and QDs) may be artificial designs or nature-inspired designs from plants (epidermal cell of leaves of shade adapted plants), insects (moth-eye and butterfly wings) and other organisms (bacterial chlorosomes). 1,34 Various fabrications methods have been exploited to study the effect of nanostructures, including physical and chemical deposition techniques, namely nanoimprint lithography, 35,36 electrodeposition, 37 soft imprinting method, 38 rapid ion etching, 38 magnetron sputtering, 39 chemical vapor deposition 40 and many other different techniques.…”