Analysing the thermal and electrical properties of Cocos nucifera shell-based nanofluids as coolant feasibility proton exchange membrane fuel cell

Abstract

For an enhancement of the thermal and electrical conductivity of the proton exchange membrane fuel cell (PEMFC), extensive research is actively conducted on various waste bio sources. PEMFC offers the cleanest form of energy, an electrochemical energy conversion device that possesses zero emissions with by-products such as heat and water. In PEMFC, conventional coolants such as water and water:ethylene glycol mixture does not attain the substantial results in terms of heat dissipation, which impacts performance gradually reduces the operating life of the cell. Usually, bio-sources are environmentally friendly and have merits over chemically prepared methods. Bio-based nanofluids have remarkable performance in terms of heat transfer, lower electrical conductivity, and low corrosiveness in the system compared to other metal-based fluids and base fluids, which have also gained a great deal of scrutiny over the past few decades. In this research, bio-sourced Cocos nucifera shell (CNS) is utilised at various concentrations, such as 0.1 vol.-%, 0.3 vol.-% and 0.5 vol.-%, dispersed with a base fluid such as water (W), and ethylene glycol (EG) (80:20) is analysed prior to actual full stack PEMFC. Consequently, heat transfer has been improved by 13% for CNS in 80:20 (W:EG) at 0.5% volume concentration compared with W:EG (80:20). On the basis of findings on thermal, hydraulic and electrical conductivity, various properties have also been determined. Despite the drawbacks of the experimental design, it was concluded that up to 0.5 vol.-% CNS in an 80:20 (W:EG) nanofluid could be used as a cooling medium for PEMFCs with no adverse effects on the electrical performance. It was also observed that the nanofluid improved the efficiency of the fuel cells by reducing the ohmic losses.