Nanosynthesis of silver nanoparticle for thermal conductivity enhancement of nanofluids for heat transfer applications

Abstract

Buildings is one the major contribution to global energy consumption in which a large proportion of this energy is used for thermal comfort in buildings, especially in indoor mechanical heating, ventilation and air-conditioning installations (HVAC) that take up as high as 60% of the total energy consumed in buildings (Cao et al., 2016). To address this growing concern, improving building energy efficiency has been the key focus for many researches, specifically in nanotechnology and nanofluid (Yang et al., 2014). Literature reviews have found that utilizing nanofluids can result in significant cost savings and enhanced performance of heat transfer applications. Therefore, this paper has identified potential nanomaterials from literature reviews to examine its actual thermal conductivity enhancement. Through the tests conducted in this study, Graphite, Aluminium Oxide and Titanium Dioxide nanoparticles were found to be able to disperse rather uniformly in water and the enhancement factor of nanofluids can be achieved up to 36.3% at 5 wt% using nano-graphite particles. Results also show that the thermal conductivity of nanofluids is enhanced with increased nanoparticle concentrations from 1 wt%, 3 wt% to 5 wt%. In the present work, synthesized silver nanofluids were also prepared and tested for its thermal conductivity enhancement and was found to have good enhancement factor and thermophysical properties. Based on the experimental results and studies conducted, it is pivotal that future research and tests are focused on improving the mechanical properties and performance of nanoparticles in order to operate effectively on actual applications.

Keywords: Nanofluids, Thermal Conductivity, Thermophysical Properties, Nano-Graphite Particles, Silver Nanofluids, Heat Transfer Applications