Influence of hybrid nano-coolant on the performance of engine radiator coupled with nano-composite-assisted PCM cooler

An automobile radiator incorporated with novel Hybrid Nano-Phase Change Material (HyN-PCM) cooler was fabricated and experimentally analyzed using novel Hybrid Nano-coolant (HyNc). Graphene nano-platelets (GnP) and multi-walled carbon nano-tubes (MWCNT) nano-particles were selected and taken in 50:50 ratio for hybrid nano-particle preparation. Non-covalent method was adopted to prepare both HyNc and HyN-PCM. Nano-coolants were prepared for dissimilar volume proportion from 0.1 to 0.5% in five stages. HyN-PCM was prepared for 1% mass fraction of nano-particles. Experiments were carried out for dissimilar coolant flow rates (CFR) varying from 20 g s −1 to 100 g s −1 in five stages and inlet temperatures of 50 °C and 70 °C. Constant air velocity of 5 m s −1 is maintained for all experiments. The experiments were conducted and compared between two methods: (i) radiator and (ii) radiator with PCM cooler. The thermal conductivity (TC) of the prepared HyNc enhances to 59%, when compared with base coolant. At 70 °C inlet temperature and 0.5% volume proportion, the highest convective heat transfer coefficient (CHTC) and overall heat transfer coefficient (OHTC) improvement was found as ~ 75% and ~ 125%. The highest effectiveness of the radiator with HyN-PCM cooler is increased up to ~ 1%, when compared with radiator without cooler. Therefore, it is recommended to install the PCM cooler for peak load conditions. Twenty-five percent pressure drop increment was observed, at low operating temperatures. Because of the enriched heat transport performance, the implementation of HyN-PCM cooler is recommended, and the prepared HyNc is to be an alternate for the prevailing coolants. Graphical abstract