Passive heat extraction and electricity generation

摘要

A closed-loop heat exchange system and related methods for harnessing subterranean heat energy from a subterranean zone having a passive heat transfer device with multiple operational modes for targeting hotspots within the subterranean zone and adjusting the rate of energy harnessed according to consumption demands. The system can also have at least one enhanced surface section for increasing the heat exchange efficiency and/or a variable pump for controlling the rate at which the working fluid travels through the passive heat transfer device.

主权项

1. A closed-loop system for harnessing subterranean heat energy from a selected subterranean zone having a quantity of subterranean material to a surface location, the system comprising:
a first well bore comprising a first substantially vertical well bore section from the surface location to the selected subterranean zone and at least a second well bore section extending away from the first substantially vertical section in an angular direction into at least a portion of the selected subterranean zone; a first substantially vertical transfer section having an outer casing located within the first substantially vertical well bore section; a first passive heat transfer device extending away from the substantially vertical transfer section within the second well bore section, the first passive heat transfer device having an outer casing and an inner tubing, the outer casing of the first passive heat transfer device connected to the substantially vertical transfer outer casing, the outer casing of the first passive heat transfer device having a sealed distal end, at least a portion of the outer casing of the first passive heat transfer device having a rifled configuration, and the inner tubing of the first passive heat transfer device configured within the outer casing of the passive heat transfer device in a concentric arrangement defining a first fluid path in an annulus space between the outer casing of the passive heat transfer device and the inner tubing, the first passive heat transfer device having a second fluid path within the inner tubing, and the inner tubing having an open end proximate the sealed end of the outer casing of the passive heat transfer device such that the first and second fluid paths are in fluid communication; a working fluid located within the first and second fluid paths; and an output apparatus for receiving a heated working fluid from the selected subterranean zone.