Hi, I already made another simulation, residuals in energy equation do not decreases below 1e-5. i´m monitorig the absorber plate temperature and it's stablized after 300 interations, but outlet velocity and inlet pressure are not. I'm not sure what it should look like, i generated vertex average reports.

I think mass flow rate is fine, but i´m not sure about total heat transfer rate, i attach images.

Thank you very much, i´m a begginer.