Experimental Study On Ai2o3-Tio2 And Ai2o3-Cuo Hybrid Nanofluids For Lithium Ion Battery Cooling

• Main Author: Wanatasanappan, Vignesh Vicki
• Format: Thesis
• Language: English
• Published: 2021
• Subjects: T Technology; TJ Mechanical engineering and machinery
• Online Access: http://eprints.usm.my/55321/1/Experimental%20Study%20On%20Ai2o3-Tio2%20And%20Ai2o3-Cuo%20Hybrid%20Nanofluids%20For%20Lithium%20Ion%20Battery%20Cooling.pdf; http://eprints.usm.my/55321/

Lithium ion battery (LIB) is widely used in electric vehicles (EVs) and hybrid electric vehicles (HEVs) due to its high energy density and low charge loss when not in use. However, the use of high energy density LIB has thermal runway risk, which requires an effective thermal management system. This research focuses on formulating hybrid nanofluids and evaluating the thermal performance of hybrid nanofluids for cooling LIB cells. Two different types of hybrid nanofluid containing Al2O3, TiO2, and CuO nanoparticles are developed using water and water/EG as the base fluid. The Al2O3, TiO2, and CuO nanoparticles were characterized using XRD and FESEM technique. The effect of nanoparticle mixture ratio and volume concentration on the thermophysical properties are investigated experimentally at temperatures between 30 to 70ºC. Based on the experimental data, regression analysis was performed to model new correlations that can be used to estimate the thermal conductivity and dynamic viscosity of TiO2-Al2O3/water and Al2O3-CuO/water-EG hybrid nanofluid. The average crystallite size of Al2O3, TiO2, and CuO nanoparticles calculated using the XRD data is about 8, 19, and 24 nm, respectively. The Al2O3-CuO hybrid nanofluid achieved the maximum thermal conductivity enhancement of 12.32% for the mixture ratio of 60:40. In contrast, the TiO2-Al2O3 hybrid nanofluid recorded the maximum thermal conductivity enhancement of 66.5% for the mixture ratio of 50:50 at a temperature of 70ºC. Besides, the dynamic viscosity results show that TiO2-Al2O3/water nanofluid has lower viscosity compared to Al2O3-CuO/water-EG hybrid nanofluid. The correlation model were developed for thermal conductivity and xx viscosity estimation indicates a good agreement between the experiment and predicted data with a standard error of less than 10%. The thermal performance of both nanofluids is tested using a novel thermal management system developed based on a liquid cooling system using mini channelled cooling block. The effect of nanofluid volume concentration and volumetric flow rate on the cooling performance of LIB was tested experimentally. The TiO2-Al2O3 hybrid nanofluid showed an excellent cooling performance with 74.9% enhancement in the heat transfer coefficient compared to the base fluid. The use of TiO2-Al2O3 hybrid nanofluid reduces the LIB temperature by about 12.35ºC compared to Al2O3-CuO hybrid nanofluid, which can only reduce 10.06ºC. The friction factor computed for the TiO2-Al2O3 hybrid nanofluid is significantly lower than the Al2O3-CuO hybrid nanofluid. The use of hybrid nanofluid was able to maintain the temperature of the LIBs at safe operating temperature and has a high potential to be used in cooling LIB module for EVs and HEVs.