Abstract
This work investigates a new hybrid thermal management system (TMS) for light electric vehicle (LEV) battery packs that uses dielectric liquid immersion cooling and heat pipes to effectively control lithium-ion battery (LIB) thermal load. The proposed TMS exploits the heat pipes' excellent heat dissipation and dielectric fluids' uniform cooling. Different commercial dielectric oil chemistries
(Cargill DE-11772 and EF-3221, LK-STO50, and MIVOLT-DFK) are evaluated as heat transfer fluids (HTFs) and compared with air and deionised water as benchmark. A 3D steady-state CFD model is developed in Ansys 2024R1 to simulate the proposed TMS for a
4S4P (14.8V, 10 Ah) Lithium-Nickel Manganese Cobalt (NMC) battery pack. Under typical 2C discharge rate, the model preliminarily
examines the TMS thermal performance when simulating heat transfer with and without buoyancy effects. Buoyancy improves cooling
performance, especially for viscous fluids, lowering battery, HTF, and heat sink temperatures by 20%. With modest LIB heat generation
rates (up to 25 kW/m³), the TMS ensures effective cooling with minimum temperature increase. However, when reaching heat generation
rates up to 100 kW/m³, the battery temperature reaches 91.13°C, revealing the system's cooling capability limitations. The study examines
the effect of changing heat sink and insulation equivalent convective heat transfer coefficients. Increasing the heat sink coefficient from 10 to 100 W/m²K lowers the battery temperature from 138°C to 49°C, while increasing the insulation equivalent heat transfer coefficient from 1 to 50 W/m²K lowers battery temperature from 92°C to 46°C. This study shows that the hybrid TMS using heat pipes and immersion cooling may improve compact LEV safety, performance, and battery longevity under high-demand situations.
(Cargill DE-11772 and EF-3221, LK-STO50, and MIVOLT-DFK) are evaluated as heat transfer fluids (HTFs) and compared with air and deionised water as benchmark. A 3D steady-state CFD model is developed in Ansys 2024R1 to simulate the proposed TMS for a
4S4P (14.8V, 10 Ah) Lithium-Nickel Manganese Cobalt (NMC) battery pack. Under typical 2C discharge rate, the model preliminarily
examines the TMS thermal performance when simulating heat transfer with and without buoyancy effects. Buoyancy improves cooling
performance, especially for viscous fluids, lowering battery, HTF, and heat sink temperatures by 20%. With modest LIB heat generation
rates (up to 25 kW/m³), the TMS ensures effective cooling with minimum temperature increase. However, when reaching heat generation
rates up to 100 kW/m³, the battery temperature reaches 91.13°C, revealing the system's cooling capability limitations. The study examines
the effect of changing heat sink and insulation equivalent convective heat transfer coefficients. Increasing the heat sink coefficient from 10 to 100 W/m²K lowers the battery temperature from 138°C to 49°C, while increasing the insulation equivalent heat transfer coefficient from 1 to 50 W/m²K lowers battery temperature from 92°C to 46°C. This study shows that the hybrid TMS using heat pipes and immersion cooling may improve compact LEV safety, performance, and battery longevity under high-demand situations.
| Original language | English |
|---|---|
| Title of host publication | Proceedings of the 10th World Congress on Momentum, Heat and Mass Transfer (MHMT 2025) |
| Publisher | Avestia |
| DOIs | |
| Publication status | Published - Apr 2025 |
Keywords
- Lithium-Ion Batteries
- Light Electric Vehicles
- Thermal Management
- Immersion Cooling
- Dielectric Oils
- Heat Pipes
- Passive Cooling
