Water flow needed in function of thermal necessities

Hi, I am new here.

I am working on a Underground Thermal Energy Storage project and I am wondering how I should calculate the flow that I need to inject or extract if I know the Heat demand (12MWh) that I have to supply with the extraction.

The extraction supplies District Heating (floor heating), at least 38 degrees, but I don't have more data.


If somebody knows any software to [B]calculate the flows, pumps and the heat exchangers[/B], or any other forum where I can find my answers I would be very glad.

Sorry if I wrote this in a wrong place.