GEOTHERMAL POWER PLANT

摘要

A plant for exploiting geothermal energy by circulating water or another fluid through a non-porous geological formation at a substantial depth below the earth surface, comprising multiple heat absorbing/production holes penetrating the said formation, with a total length of several kilometers and spaced more than 50 m apart. The production holes are connected to the surface by one single combined supply and return hole in which upward and downward flow is separated by a pipe comprising an insulating material and a seal. At the given positions of the common supply and return hole manifold zone designs connect the hole to the multiple production holes. The supply and return holes and production holes are closed circuits for transport of a fluid such as water through the said formation. A method for designing and establishing the plant is also disclosed.

主权项

1. A geothermal energy plant for extracting energy from rock via a combined supply (20) and return (1) hole (22) extending from the surface wherein a fluid is circulated from the surface through said supply hole (20) and returned to the surface through the return hole (1), and where a pipe (5) separates the supply and return flow in the combined supply and return hole (22), thus forming an annulus and a central flow path, wherein that at a given depth a seal (66) is installed sealing the annulus space by surrounding the pipe (5) separating the supply flow from the return flow, further the combined supply and return hole is extended below the seal 66 forming a lower return hole (1′), the plant further includes one first manifold zone (8) above the seal (66) which is connected with one end of at least one production hole (3, 4; 33 & 33′, 34 & 34′) formed in the rock, and where the other end of the at least one production hole is connected with the lower return hole (1′) in one second manifold zone (9) arranged below the seal (66), thus forming a closed-loop in which a working fluid can be circulated.