Counterflow Regolith Heat Exchanger

The counterflow regolith heat exchanger (CoRHE) is a device that transfers heat from hot regolith to cold regolith. The CoRHE is essentially a tube-in-tube heat exchanger with internal and external augers attached to the inner, rotating tube to move the regolith. Hot regolith in the outer tube is moved in one direction by a right-handed auger and the cool regolith in the inner tube is moved in the opposite by a left-handed auger attached to the inside of the rotating tube. In this counterflow arrangement a large fraction of the heat from the expended regolith is transferred to the new regolith. The spent regolith leaves the heat exchanger close to the temperature of the cold new regolith and the new regolith is pre-heated close to the initial temperature of the spent regolith. Using the CoRHE can reduce the heating requirement of a lunar ISRU system by 80%, reducing the total power consumption by a factor of two.