Method of and apparatus for controlling the operation of a valve that regulates the flow of geothermal fluid

A method for controlling the operation of a valve regulating the flow of geothermal fluid comprising geothermal brine and steam through the valve, said valve supplying the fluid to a geothermal plant, said method comprising the steps of:

• (a) determining the maximum permitted value of at least one quantity effecting the operation of the geothermal plant;
• (b) setting preset value for said at least one quantity less than the maximum value of the quantity;
• and
• (c) reducing the flow of fluid through the valve when the value or said at least one quantity reaches its preset value for maintaining the operation of the geothermal plant;
• and
• (d) including separating the geothermal fluid into geothermal brine and steam and supplying the steam to said geothermal plant.

A method for controlling the operation of a valve regulating the flow of geothermal fluid comprising geothermal brine and steam through the valve, said valve supplying the fluid to a geothermal plant, said method comprising the steps of:

• (a) determining the maximum permitted value of at least one quantity effecting the operation of the geothermal plant;
• (b) setting preset value for said at least one quantity less than the maximum value of the quantity;
• and
• (c) reducing the flow of fluid through the valve when the value of said at least one quantity reaches its preset value for maintaining the operation of the geothermal plant;
• and
• (d) wherein said quantity is the pressure of the geothermal fluid at an injection well where the geothermal fluid is injected.

A geothermal power plant operating on geothermal fluid derived from a production well, said plant comprising:

• a) a plant pressure control valve for controlling the flow of said fluid from the production well to said geothermal plant;
• b) a central controller for controlling the setting of said valve;
• c) means responsive to at least one parameter of said power plant which affects the operation of the power plant for producing a control signal, said parameter having a maximum permitted value;
• d) means for applying said control signal to said central controller;
• e) means for applying to said central controller a preset value that represents less than the maximum value of the quantity;
• and
• d) said central controller being operational to reduce the flow of fluid through said plant pressure control valve when the value of said at least one parameter reaches its preset value for maintaining the operation of the geothermal plant.