Problem modelling heat loss in thermal fluid pipe

I have a problem with my simscape thermal liqiud model, I am trying to model a pipe that loses heat to the environment but no matter what I try the pipe only seems to get hotter. I have a heat input coming into the system before the pipe and then I have a fixed temperature source connected to the thermal port of the pipe via a conduction and a convection block in series. I was hoping this would represent heat leaving the system but even when i set the fixed temperature to really low the fluid after the pipe is still hotter than before the pipe.

Would anyone be able to offer any suggestions as to how i might fix this?

Thanks

[Sathvik]

Hi

Can you please provide your model to get a better understanding of the issue that you're facing.

[Yifeng Tang]

The pipe contains the convective heat transfer correlation equations between the pipe wall and the fluids. I have a suspicion that your pipe parameters don't give the expect heat transfer area. Like Sathvik said, sharing a model may help diagnose your problem.

[Rohan]

Possible reasons for the pipe heating up:

1. Incorrect sign in heat transfer block: Double-check the sign (+/-) in your conduction and convection block parameters. A positive sign signifies heat flowing into the pipe, while a negative sign represents heat flowing out. Ensure the heat sink temperature (fixed temperature source) is set lower than the fluid temperature for heat transfer to occur in the desired direction.
2. Missing environmental temperature block: Are you using an "Ambient Temperature" block from the Simscape>Foundations>Thermal>Utilities library at the other end of the conduction and convection path? This block connects the pipe wall to the surrounding environment and establishes the temperature gradient for heat transfer.
3. Incorrect pipe material properties: The thermal conductivity and emissivity of the pipe material play a crucial role in heat transfer. Ensure these properties are entered correctly in the "Pipe (TL)" block parameters. Higher conductivity allows faster heat transfer to the environment, while higher emissivity increases radiative heat loss.
4. Dominant heat source: Perhaps the heat input you mentioned is overwhelming the heat loss through the pipe. Check the relative magnitudes of both heat sources and ensure the heat loss mechanism is adequately modeled.
5. Model configuration errors: Verify your model connections and block settings. Are all the blocks connected correctly based on the flow direction and heat transfer paths? Double-check any custom block parameters or subsystems you might have implemented.

Troubleshooting :

• Run a steady-state simulation with constant heat input and observe the temperature throughout the pipe. This can help diagnose if the heat transfer path is set up correctly.
• Monitor the heat flow rates in your conduction and convection blocks. These values should be positive for heat leaving the pipe.
• Compare your model results with analytical calculations or reference data for similar systems. This can help confirm the accuracy of your model parameters and assumptions.

resources:

• MathWorks documentation on Thermal Liquid systems: https://www.mathworks.com/help/simscape/ug/thermal-liquid-modeling-workflow.html
• Problem modelling heat loss in thermal fluid pipe (MATLAB Answers): https://www.mathworks.com/help/hydro/ug/model-a-thermal-liquid-pipeline.html
• Modeling Thermal Liquid Systems (MathWorks Help): https://www.mathworks.com/help/simscape/ug/thermal-liquid-modeling-workflow.html

[Yifeng Tang]

Hi @Rohan, was your comment based on your own experience and knowledge of Simscape or it's machine/AI/GPT-generated? I found the content contains many errors, to the extent that there is something debatable in EVERY bullet point.