power and water, page-18

NeilN, I had never thought much about the pumping of the primary liqid back down the hole, or that it might require cooling.
The liqid should come to the surface initially somewhere around the 240c range. After passing through the above ground heat exchanger I am not sure how hot it might still be. Let us just say it has dropped 50% in temp.ie. to around 120c.

This could pose problems as the liquid returns to the injection pump (to be sent back down Hab.1)and is subject to a sharp drop in pressure at the suction side of the pump causing it to flash a considerable amount of steam thus causing cavitation and damaging conditions to the pump and inneficient performance.
Ridiculously you could find yourself having to cool the liquid further to overcome this problem.
Of course you would endeavour to avoid this waste and there might be several options.

geojac