Hi @JIN010813,
The best option would be combining this kind of porous media (foam) with a heat loss model for the entire structure, but it would be only possible in our next release in first quarter of 2024. For while, an alternative way would be using just our porous media capability analyzing the tubes of the heat exchanger, but this may result in low accuracy in comparison for what you are expecting.
I would suggest to give a try with your results, and then if they are not satisfactory close you can expect it to be completed simulated in the next quarter.
best