ABSTRACT
This study explores the performance of a steady-state flow single-phase non-conductive liquid immersion cooling system in a single-cell Li-ion battery under a variety of thermal environments such as 25°C, 40°C, and 60°C and tested at different charge C-rates. The experimental results show that the proposed cooling system exhibited the best cooling performance of less than 5°C and a significant temperature rise reduction of 34% at 3C rate under the ambient temperature of 25°C. Also, it provided uniform temperature distribution within the cell when charged at fast charge rates of 2C and 3C operations.
Nomenclature
= | Cell specific heat capacity (J/kgK) | |
= | Heat dissipation rate (W) | |
h | = | Convective heat transfer co-efficient for free air (W/m2 K) |
= | Ambient Temperature (oC) | |
= | Cell surface Temperature (oC) | |
A | = | Surface Area of cell (m2) |
L | = | Characteristic length (Volume of cell/Area of cell) |
= | Thermal Conductivity (W/mK) | |
= | Temperature difference between battery surface and ambient temperature (oC) | |
= | Thermal conductivity of the fluid (W/mK) | |
= | Specific capacity of the fluid (J/kgK) | |
= | Density of the fluid (kg/m3) | |
= | Fluid temperature (oC) | |
µ | = | Dynamic viscosity of the fluid (Ns/m2) |
= | Velocity vector | |
g | = | Gravitational acceleration (9.81 m/s2) |
β | = | Coefficient of volume expansion of the fluid (K−1) |
= | Temperature difference between mean temperature of battery system and ambient temperature in immersion cooling (oC) | |
= | Convective heat transfer co-efficient for fluid (W/m2 K) | |
= | Rate of Heat transfer by convective dielectric fluid flow (W) | |
Nu | = | Nusselt number |
Pr | = | Prandtl number |
Ra | = | Rayleigh number |
Gr | = | Grashof number |
∆T | = | Difference in temperature rise between battery and ambient in natural air convection cooling (oC) |
dT/dt | = | Rate of change of battery temperature (oC/min) |
T1 | = | Negative tab temperature (oC) |
T2 | = | Positive tab temperature (oC) |
T3 | = | Battery body temperature (oC) |
T4 | = | Fluid temperature far from battery surface (oC) |
Abbreviations
BTMS | = | Battery thermal management system |
EVs | = | Electric Vehicles |
HEVs | = | Hybrid Electric Vehicles |
C-rate | = | Current rate |
NACC | = | Natural air convection cooling |
CC-CV | = | Constant current-Constant voltage |
SFIC | = | Static flow of immersion cooling |
Acknowledgments
Author wishes to express her gratitude thanks to the CSIR - Centre for Electrochemical Research Institute for the extensive support. ‘Council of Scientific and Industrial Research’ provides financial support for this project.
CSIR-CECRI manuscript communication number
CECRI/PESVC/Pubs/2023-055
Disclosure statement
No potential conflict of interest was reported by the authors.