system for extracting heat from hot dry rocks and geothermal plant

摘要

The system according to the present invention serves to extract heat from hot rocks (4) and is adapted to being inserted entirely into a well (1) which reaches said hot rocks (4); it comprises a closed hydraulic circuit adapted to the circulation of a heat transport fluid, and in addition: a bulb (5) of cylindrical shape adapted to circulate said fluid in its interior and adapted to be placed in contact with said hot rocks (4) on the outside to absorb heat from these rocks and transfer the heat to said fluid circulating in its interior, a first conduit (6) adapted to conduct said fluid to and within said bulb (5), a second conduit (7) adapted to conduct said fluid out of and away from said bulb (5), thermal insulating means (81, 82) of cylindrical shape, aligned to said bulb (5), arranged along said well (1) up to said bulb (5), and adapted to thermally insulate said first and second conduits (6, 7) between them and from soil and / or surrounding rocks. The bulb (5) further comprises means (14, 18, 19, 110, 125) for generating turbulent motions in said circulating fluid in its interior and a plurality of fins (15, 121) which extend from the peripheral zone of the bulb (5) towards the inside, arranged to come into contact with said fluid in turbulent motion, thereby increasing the heat transfer toward said fluid because the increase of the effective surface area of heat transfer. One or more of these systems can be used in a geothermal plant.