Method for inhibiting scale and geothermal power generating device

摘要

A method for suppressing scale that contains calcium and silica and a geothermal power generating device that can operate economically while suppressing deposition of scale. The geothermal power generating device is provided with: pipes through which geothermal water that is collected from a producing well flows; a chelating agent supply unit that supplies a chelating agent to the geothermal water flowing within the pipes; an alkaline agent supply unit that supplies an alkaline agent to the geothermal water flowing within the pipes; a chemical agent mixing unit provided on the downstream side from the chelating agent supply unit and the alkaline agent supply unit in the pipe pathway; a first detector that measures the inlet pressure for the chemical agent mixing unit or the fluid flow rate on the inlet side; and a second detector that measures the outlet pressure for the chemical agent mixing unit or the fluid flow rate on the outlet side. If the difference between the value detected by the first detector and the value detected by the second detector exceeds a preset upper limit threshold value, the chelating agent supply unit is controlled so as to increase the amount of the chelating agent supplied and such that the chelating agent is supplied in an increased supply amount until the difference in the detected values falls below a preset lower limit threshold value.