With the ever-increasing demand for energy, ways to find efficient energy sources have become more critical than ever before. While catering to this energy demand, one element needs attention: the enhancement of thermal conductivity. A new study in the journal Materials Today: Proceedings offers a novel approach to enhancing the thermal conductivity of nanofluids for energy-based applications.
Study: Thermal conductivity enhancement of magnetic nanofluids for energy applications. Image Credit: Mia Stendal/Shutterstock.com
What are Nanofluids?
Nanofluids (NFs) are a level of liquids created by scattering nano-sized components in various sizes and forms in base fluids. Essentially, NFs are colloidal solutions containing nanoparticles.
Numerous studies on NFs have shown that they offer improved thermophysical characteristics such as increased thermal conduction, good thermal diffusion, and convection-based heat transfer when compared to other base fluids such as oil, ethylene glycol, water, and so on.
Nanofluids – They're Great, but…
Nanofluids have shown remarkable potential for utilization in various technical sectors. Yet, key challenges limit their application.
Among the most important concerns is NF stability, which poses a significant barrier in terms of creating stable, robust, and trustworthy NFs over time. A fundamental challenge for increasing the usage of NFs for a spectrum of uses is the technique for the layout of these stable NFs.
Among the many places where NFs have played a part, their impact on convection and conduction-based heat transfer capabilities is notable.
Heat Transfer Fluids
Heat transfer is important in a variety of different sectors. However, the typical fluids employed as heat transfer fluids (HTFs) have extremely poor thermal conductivity. To address this problem, a great deal of interest has developed towards NFs for obtaining enhanced heat transfer capabilities instead of conventional HTFs.
The ability of NFs to provide enhancement in thermal conductivity has translated into NFs being utilized in several heat-based applications such as microelectronic cooling systems, fuel cell coolants, vehicle radiators, geothermal plants, and efficient heat transfer media for solar collectors, solar thermoelectrics, PVT systems, and so on.
Research on Direct Absorption Solar Collectors
Recently, new research on purely direct absorption solar collectors (DASC) was conducted to demonstrate the effects of the DASC's operating conditions on its performance. Here, a heat transfer fluid made by scattering NPs in deionized water was used.
According to the test findings, the magnetite NF had the greatest thermal and energy efficiency. It is worth noting that NFs are efficient conductors of solar radiation in the absorption spectrum.
Highlights of the Study
This research aimed to improve the thermal conduction of distilled water by utilizing magnetic NPs for solar energy-based applications.
Ferric oxide-based NPs dispersed in distilled water (deionized) along with a surfactant were created in various volume proportions and termed magnetic NFs.
The team discovered that the structural data verified the synthesis of ferric oxide-based NPs, as shown by the presence of the relevant functional groups of the corresponding substances in the NPs. Additionally, the thermal conductivity of magnetic NFs was effectively predicted by traditional models, emphasizing the need to address magnetic NFs at extremely low volume fractions.
It was concluded that given the increased thermal performance efficiency of magnetic NFs, the discoveries have aided in defining as-prepared magnetic NFs as a feasible choice for heat transfer and energy-based applications.
Kumar, P., Parameshwaran, R., & Sreedhar, I. (2022). Thermal conductivity enhancement of magnetic nanofluids for energy applications. Materials Today: Proceedings, Available at: https://doi.org/10.1016/j.matpr.2022.05.556