In the convective cooling equation, the surface area of the fluid in contact with the heat source is an important parameter, directly proportional to the amount of heat that can be removed from the cells:
Qc = hA(Ts-Ta), where A is the surface area of the cells touching the air.
We will make several assumptions in these calculations to make the calculations easier and assume a worst case scenario.
Assumptions
- Cells are modeled as 18.5mm x 18.5mm rectangles instead of cylinders
- Cell height will be 50mm, as 5mm as each end is inside the acetal capture plates
- An additional 5mm is deducted because airflow near the plates is reduced
- Cells are arranged in groups of 8 cells in the direction of the airflow, 2 cells across
- 3 of the groups per module (see the page: New Module Layout)
Calculations
MODULE
18.5mm * 8 cells * 6 side rows * 50mm height = 44 400mm2 = 0.0444m2
PACK
0.0444m2 * 18 modules = 0.7992 = 0.8m2
Our conservative estimate of the cell area is 0.8m2.