| 摘要 |
This geothermal heat exchanger 1 is provided with a water injection pipe 2, which is provided underground and to which water is supplied from above the ground, and a steam extraction pipe 3, which is provided underground so as to be in contact with the water injection pipe 2. A plurality of jetting ports 5 are provided in a lower region of the steam extraction pipe 3, and the pressure inside the steam extraction pipe 3 is reduced close to the pressure required by a turbine 6. The steam extraction pipe 3 is formed such that the diameter of the steam extraction pipe 3 becomes smaller from below on a geothermal zone side to above on a ground surface G side. Heat from a geothermal zone 4 is supplied to the water that is supplied to the water injection pipe 2, said water becomes high-temperature pressurized water, which is jetted from the jetting port 5 into the steam extraction pipe 3 in a spray state and is converted into a single-phase steam flow, and power is generated by a generator 7. Furthermore, by lowering the water level of the water that is supplied to the water injection pipe 2, an air layer 19 is formed in an upper portion of the water injection pipe 2, and a resulting heat insulation portion is provided in a region that is in contact with a low-temperature ground zone 26 that is close to the ground surface. |
