How to model the air cooling of a battery

Hi all,

I need to model the forced air cooling of this battery module formed by batteries, and contained in that closed housing, with only openings for air entry and exit, air is introduced inside with the help of two parallel fans.

[William Rose]

matlab or simulink?

[Jose]

Simulink

Answer 1

[Ayush]

Hi Jose,

I understand that you need to model the forced air cooling of a battery module which can be quite fascinating and interesting! It's like giving your battery a breath of fresh air to keep it cool and efficient.

Here is an overview of the process, along with some MATLAB code to kick-start your analysis:

1. System:

• You can try to understand the configuration, material properties and heat generation rates of batteries.
• You can note the desirable parameters like dimensions, materials and thermal properties of housing beforehand.

2. Some Necessary Data:

• Some properties like thermal conductivity, specific heat, and density of the battery materials and housing can be obtained through various resources.
• You can try obtaining data on heat generation rates as well as fan performance curves under different operating conditions.

3. Choose a Modelling Approach and setup the model:

• You can try generating simplified equations for quick estimates, suitable for early-stage analysis.
• After theoretical calculations, accuracy can be verified using the results of detailed simulations, capturing complex airflow and heat transfer phenomena.

4. Simulate and analyse the results for the desirable parameters:

• You can check for hot spots and ensure temperatures remain within safe limits. Also, Airflow patterns can be visualized to identify any areas of recirculation or stagnation. Some other factors like pressure difference might be used to ensure fans can maintain the desired flow rate.

This was a basic overview of designing an air cooling of a given battery. Here is the MATLAB code depicting the process:

% Parameters 
numBatteries = 10; % Number of batteries 
batteryHeatGen = 5; % Heat generation per battery (W) 
totalHeatGen = numBatteries * batteryHeatGen; % Total heat generation (W) 

% Air properties 
airDensity = 1.225; % kg/m^3  
airSpecificHeat = 1005; % J/(kg*K) 
airFlowRate = 0.1; % m^3/s  

% Housing properties 
thermalConductivity = 200; % W/(m*K) 
housingThickness = 0.01; % meters 
housingArea = 0.5; % m^2 

% Initial conditions (in Celsius) 
initialTemperature = 25;  
ambientTemperature = 25;  

% Time parameters 
simulationTime = 3600; % seconds 
timeStep = 1; % seconds 
timeVector = 0:timeStep:simulationTime; 

% Preallocate temperature array 
temperature = zeros(size(timeVector)); 
temperature(1) = initialTemperature; 

% Simulation loop 
for t = 2:length(timeVector) 
    % Heat transfer calculations 
    convectiveHeatLoss = airFlowRate * airDensity * airSpecificHeat * (temperature(t-1) - ambientTemperature); 
    conductiveHeatLoss = (thermalConductivity * housingArea / housingThickness) * (temperature(t-1) - ambientTemperature); 
    
    % Net heat change 
    netHeatChange = totalHeatGen - (convectiveHeatLoss + conductiveHeatLoss); 
    
    % Temperature update 
    temperature(t) = temperature(t-1) + (netHeatChange / (airDensity * airFlowRate * airSpecificHeat)) * timeStep; 
end 
figure; 
plot(timeVector, temperature, 'LineWidth', 2); 
xlabel('Time (s)'); 
ylabel('Temperature (°C)'); 
title('Battery Module Temperature Over Time'); 
grid on; 

For further information, you can refer this answer:

https://www.mathworks.com/matlabcentral/answers/2144199-how-to-model-the-battery-module-with-forced-air-cooling-in-simscape

Hope this helps!