Simulink thermal coppling problem

I have this problem where i seem to have some thermal coppling of my Tank(G-TL) with my Constant Volume Chamber. Yet there shouldnt be anything that does effect the temperature in my Constant Volume Chamber i still have something definitely influencing it. When I only simulate the outflow of my Constant Volume Chamber (pink) filled with N2 with a start value of 300 bar and a starting temperature of 300 Kelvin, i get a temperature of 267 Kelvin at the point my Chamber pressure dropped down to 200 bar. But if I simulate the whole circuit (screenshot) i get a different temperature after i dropped down to 200 bar in my Constant Volume Chamber depending on the settings i set my Tank(G-TL) (pink+yellow) on. It would be very nice if someone has an idea what could cause this effect of the temperature behaviour of my Constant Volume Chamber in this Simulink modell?

Answer 1

[Aman Banthia]

Hi Philippe,

I understand that you are having issues with Thermal Coupling in the Constant Volume Chamber. The temperature coming after running the Simulation isn’t the same as expected by you.

In order to assist you better, please provide the relevant code and files so that I can reproduce the issue at my end. Here are some general troubleshooting steps to overcome the issue of Thermal Coupling :

1. Examine the physical layout: Review the physical layout of your system and the connections between the Tank(G-TL) and the Constant Volume Chamber. Check if there are any direct paths for heat transfer, such as physical contact, shared walls, or pipes that could conduct heat between the two components. Look for any unintended connections that may be influencing the temperature.
2. Inspect insulation: Ensure that both the Tank(G-TL) and the Constant Volume Chamber are properly insulated. Insulation helps to minimize heat transfer between components. Check if there are any gaps or areas where insulation might be inadequate, allowing heat to transfer between the components.
3. Verify material properties: Confirm that the material properties used in your model accurately represent the actual components. Pay attention to thermal conductivity values, which indicate how easily heat can transfer through a material. Ensure that the thermal conductivity values of the materials used in the Tank(G-TL) and the Constant Volume Chamber are accurate and consistent with their physical properties.
4. Consider additional heat sources: Evaluate if there are any additional heat sources within the system that might be influencing the temperature in the Constant Volume Chamber. These could include nearby components or external factors that are not explicitly modelled but still affect the temperature. For example, if there is a heat source near the Tank(G-TL), it might indirectly impact the temperature in the Constant Volume Chamber.

Please refer to the following documentation to know more about the Constant Volume Chamber(G):

Chamber with fixed volume of gas and variable number of ports - MATLAB - MathWorks India

I hope that the above steps help you find the issue and resolve it.

Best Regards,

Aman Banthia