Due to the internal resistance of battery cells, they produce heat when a current is applied to them. We must dissipate this heat somewhere to stop the cells from heating up.
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We measured the airflow of our Noctua IPPC fan when pulling air through 1 or our prototype modules (see this page). We will be contacting Noctua to obtain a more accurate P-Q curve for their fan.
| Condition | Airflow (m3/h) | Airflow (CFM) | Static Pressure (from Cooling Technique Testing) | Static Pressure (from Noctua P-Q Curve) |
|---|---|---|---|---|
| Just fan duct | 26.97 | 15.87 | 5.55 | |
| 1 Module and fan duct | 15.52 | 9.13 | 5.6 |
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| Variable | Description | Value (Units) |
|---|---|---|
| H | Least amount of heat removed | (W) |
| Cp | Specific heat capacity of the air | 1005 (J/Kg℃) |
| M | Mass of the air | (Kg) |
| ∆T | Temperature difference | Tc - Tamb (℃) |
M = Q x ρ
| Variable | Description | Value |
|---|---|---|
| M | Mass of the air | |
| Q | Flow rate of the air | |
| ρ | Density of the air | ρ = 1.18 Kg/m3 |
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Comparing against our experimental temperature curves, it seems like we are able to remove much more heat than these calculations predict. We will repeat some measurements and review these calculations later. - remember this is 1 module, so has 18 times less heat produced than the heat production of the full pack.
Next steps: plot the temperature rise for all the cells in the pack, take the average, and determine the rate of temperature rise.
Might be useful, sometime and thought I would throw a link here - an interesting way to measure airflow in a closed pipe or duct:
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