GEOTHERMAL ELECTRICITY GENERATING SYSTEM, GEOTHERMAL ELECTRICITY GENERATING DEVICE, GEOTHERMAL ELECTRICITY GENERATING METHOD, OR MEDIUM TRANSFER PIPE, GEOTHERMAL ELECTRICITY GENERATING DEVICE AND GEOTHERMAL ELECTRICITY GENERATING METHOD EMPLOYING MEDIUM TRANSFER PIPE, AND METHOD OF INSTALLING MEDIUM TRANSFER PIPE IN FRACTURE ZONE

摘要

[Problem] To provide a geothermal heat exchanger which has a high thermal efficiency and with which it is possible to reduce the loss of heat to a non-geothermal field when hot water that has been heated deep underground is conveyed to ground level.[Solution] This geothermal electricity generating system is characterized by being provided with: a medium transfer pipe 20 which comprises a double pipe without an opening in a geothermal field S, and which has a descending region that causes a medium to descend, and an ascending region that causes the medium to ascend; a high-pressure recirculating pump 30 that feeds the medium to the medium transfer pipe 20; a vapor generator 41 which extracts vapor from the medium that has been heated by geothermal heat; a production well which is formed around the medium transfer pipe 20 and which receives geothermal water; a reinjection well which returns at least part of the geothermal water that has completed a heat exchange process; a gas-water separator 71 which includes at least one gas-water separator and which extracts vapor from the geothermal water; and an electricity generator 45 which generates electricity using the vapor.