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## Energy Pile - Heat Transfer and Laminar Flow

Good afternoon,

I'm trying to analyse an energy pile (or heat exchanger foundation) with heat transfer in solids and fluids and laminar flow.

The water pipe should have a constant temperature of 10 [degC]. The problem is that after computing the study, the water reaches 19 [degC] after 100 hours. What am I doing wrong? Basically, the water should be coming through the pipe with a constant pressure/velocity and temperature, to cold the soil in my case, or to heat the soil if the water temperature is higher than the soil's temperature. The water should flow with constant 10 [degC], from the inflow to the outflow, cooling (or heating) the soil, but my model is wrong at some point. Any idea?

Thank you very much. Regards.

1 Reply Last Post 2022年6月28日 GMT-4 14:55

Posted: 2 years ago
Updated: 2 years ago

Hello Alejandro,

The water cools the surrounding media by receiving heat from it, and therefore the water's temperature increases.

If you want your model to ignore that effect and are willing to simplify things by approximating the water temperature as a constant, then there is no reason for solving the fluid flow problem at all. You could remove the fluid domain from your geometry and impose a temperature boundary condition where the (now removed) fluid contacts the solid domain. This will have the benefit of reducing your model size.

Best,

Jeff

PS: If you do want to compute how the temperature of the water changes, a "pipe flow approach", whereby the pipe is simulated as a 1D curved entity, would be more efficient numerically. See this model and this other one for illustrations of that approach. These models are based on the Pipe Flow Module.

-------------------
Jeff Hiller

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