AN OVERVIEW OF PERFORMANCE AND APPLICATION OF NANOFLUIDS IN COMPACT HEAT EXCHANGERS
The requirements of miniaturization and higher energy efficiency in industry lead to use compact heat exchangers
which feature high heat transfer performance, smaller size, lower fluid requirement and lower cost. However, heat transfer intensification is needed in the applications of compact heat exchangers which is limited due to inherently low thermal properties (e.g., thermal conductivity) of the working fluid. On another hand, over the past two decades, there has been considerable interest in suspending nanoparticles into conventional heat transfer fluids for advanced cooling strategy in modern devices and systems. These nanoparticle-fluid mixtures widely known as "nanofluids" have many potential applications in heat transfer areas because of their intriguing properties and characteristics such as considerably enhanced thermal conductivity and convective heat transfer coefficient.
Despite growing attention in the application of nanofluids in wide variety of thermal management systems that include compact heat exchangers, literature results on the performance of nanofluids in such thermal systems are not consistent and there is clear lack in understanding and explanation of the results. It is important to critically analyze the research and development on the application of nanofluids in compact (mini-micro) heat exchangers. Thus, a critical overview of experimental studies on nanofluids' flow and heat transfer performance in these heat exchangers under various conditions such as nanoparticles type and morphology and loading is presented, besides highlighting challenges of nanofluids in this area of thermal management.