A Novel Air-Cooled Thermal Management Approach towards High-Power Lithium-Ion Capacitor Module for Electric Vehicles

Abstract

This work presents an active thermal management system (TMS) for building a safer module of lithium-ion capacitor (LiC) technology, in which 10 LiCs are connected in series. The proposed TMS is a forced air-cooled TMS (ACTMS) that uses four axial DC 12 V fans: two fans are responsible for blowing the air from the environment into the container while two other fans suck the air from the container to the environment. An experimental investigation is conducted to study the thermal behavior of the module, and numerical simulations are carried out to be validated against the experiments. The main aim of the model development is the optimization of the proposed design. Therefore, the ACTMS has been optimized by investigating the impact of inlet air velocity, inlet and outlet positions, module rotation by 90° towards the airflow direction, gap spacing between neighboring cells, and uneven gap spacing between neighboring cells. The 3D thermal model is accurate, so the validation error between the simulation and experimental results is less than 1%. It is proven that the ACTMS is an excellent solution to keep the temperature of the LiC module in the desired range by air inlet velocity of 3 m/s when all the fans are blowing the air from both sides, the outlet is designed on top of the module, the module is rotated, and uneven gap space between neighboring cells is set to 2 mm for the first distance between the cells (d1) and 3 mm for the second distance (d2).

Cooling of lithium‐ion battery pack using different configurations of flexible baffled channels

“…As batteries are tilted at an angle of 90° parallel to the airflow direction, any increase in the spaces between cells results in a fall in the maximum temperatures. Mahamud and Park 9 concluded that employing of a reciprocating cooling system can reduce the maximum temperature and temperature difference of cells pack by 1.5°C and 4°C, respectively, during of 120 s, when compared to a unidirectional flow cooling system during a period t = ∞ s. The numerical computations of Fan et al, 10 on prismatic battery packs placed in ducts with equal space on both sides of lithium ion cells, obtained the same results of Karimi et al, 8 that reducing the gap between cells and increasing coolant velocity decrease cells maximum temperature. They deduced that the gap plays an important role in determining temperature uniformity of the battery pack where it was observed that using 3 mm spacing between cells and 40.8 m 3 /h air flow are the optimum option which meets the requirements of fan power consumption, maximum temperature rise, and temperature uniformity.…”

“…The parameters of the Li-ion cell are given in Table 3. These parameters are drawn from Equations ( 3) to (7) based on the data listed in Yang et al 40 Within the coolant, the energy and momentum are conserved by the following equations 8 :…”

“…where ρ c , Cp c , T c , k c , P, μ c denote to coolant density, heat capacity, tempratute, thermal conductivity, pressure, the dynamic viscosity, and v⃗ (m/s) is coolant velocity, respectively. Formulated on the κ-ε turbulent model, the turbulent kinetic energy and its dissipation equations are given in the following equations 8 :…”

“…Within the coolant, the energy and momentum are conserved by the following equations 8 : $$$\nabla \,\cdot \,({\rho }_{c}{{Cp}}_{c}(\vec{v}-\vec{w}){T}_{c})=\nabla \,\cdot \,({k}_{c}\nabla {T}_{c}),$$$ $$${\rho }_{c}((\vec{v}-\vec{w})\,\cdot \,\nabla \vec{v})=-\nabla P+{\mu }_{c}{\nabla }^{2}\vec{v},$$$ $$$\nabla \,\cdot \,\vec{v}=0,$$$where ρ c , Cp c , T c , k c , P, μ c denote to coolant density, heat capacity, tempratute, thermal conductivity, pressure, the dynamic viscosity, and $$\vec{v}$$ (m/s) is coolant velocity, respectively.…”

“…It was shown that increasing Reynolds number minimizes cells maximum temperature and an increase in the air intake section and Reynolds number improves system pressure difference. Karimi et al 8 conducted experimental and numerical studies of an active cooling system designed to control temperature of a model with 10‐cell battery pack. The authors studied diverse parameters such as the effect of coolant velocity, fans position, the space between batteries, and the tilting of the model.…”