Augmentation of heat exchanger performance with hybrid nanofluids: Identifying research gaps and future indications - A review

Abstract

Heat exchanger studies have been conducted for several decades since the beginning of the development of heat transfer theories due to their widespread use in various industries. The ongoing research topics include heat exchanger efficiency, design parameter optimization, material development, and heat transfer technology exploration. Research has been continued to evolve nanofluid compositions, concentrations, and operating conditions that affect heat exchanger efficiency. They have used hybrid nanofluids in heat exchangers, which contain multiple types of nanoparticles or nanoparticles with additional additives, as hybrid nanofluids improve thermal performance. As a result, the development and optimization of hybrid nanofluids as a working medium in heat exchangers are gaining popularity, and the use of hybrid nanofluids in heat exchangers has already drawn a lot of interest as a viable strategy in industrial sectors. Therefore, such a surge of interest in using hybrid nanofluids in heat exchangers has resulted in a significant body of literature on this. In this review paper, the authors aim to incorporate the findings of these studies and offer a thorough evaluation of the state-of-the-art research on the application of hybrid nanofluids in various types of heat exchangers. This review provides a synopsis of the published literature on the efficacy of heat exchangers utilizing hybrid nanofluid. The researchers have also encountered and documented several challenges, including stability and aggregation, improving thermal conductivity, fluid flow characteristics, corrosion and material compatibility, cost and scalability, and determining the ideal size and shape of nanoparticles while considering environmental and health concerns. In addition, this review identifies research gaps in preventing agglomeration, ensuring nanoparticle dispersion, optimizing fluid composition to minimize flow effects, exploring and identifying materials compatible with hybrid nanofluids, investigating cost-effective methods for hybrid nanofluid production, and addressing scalability issues for widespread implementation in industrial heat exchangers. This review paper will be a valuable resource for researchers and practitioners seeking to overcome these challenges and advance the field of hybrid nanofluids for heat exchanger applications.