Abstract: The present invention provides a method of and apparatus for controlling the operation of a valve that regulates the flow of geothermal fluid that comprises geothermal brine and steam flowing through the valve to a geothermal plant. The method includes determining the maximum permitted value of at least one parameter or quantity affecting the operation of the geothermal plant, and setting a predetermined value for the at least one quantity which is less than the maximum value of the quantity. The flow of fluid through the valve is reduced when the value of said at least one quantity reaches its preset value for maintaining the operation of the geothermal plant.

Abstract: The cooling of a hot fluid is effected using a heat exchanger adapted to receive the hot fluid and liquid coolant for cooling the hot fluid such that the liquid coolant is vaporized. A turbine, having an output shaft connected to a fan, is responsive to vaporized coolant which expands in the turbine for driving the fan to move a mass of air, and produce vaporized coolant. A condenser receives the expanded vaporized coolant and is responsive to air blown by the fan, for condensing the expanded vaporized coolant thereby cooling the same and producing coolant condensate which is then returned to the heat exchanger.

Abstract: Power is generated from a two-phase geothermal fluid containing a substantial amount of non-condensable gases, typically not less than about 3% by extracting a geothermal fluid from the ground under its own pressure, and passing the extracted geothermal fluid through an indirect heat exchange device containing an organic fluid for vaporizing the latter and producing vaporized organic fluid and heat depleted geothermal fluid. The vaporized organic fluid is expanded in a turbine coupled to a generator for producing power and expanded vaporized organic fluid which is condensed to a liquid and returned to the indirect heat exchange device. Finally, the heat depleted geothermal fluid may be returned to the ground via a rejection well.

Abstract: Turbulence in a wall-bounded fluid flow field having a turbulent wall region characterized by a system of roll pairs extending in the direction of flow, and propagating structures interacting with the system of roll pairs, is controlled by introducing into the turbulent flow, a disturbance that changes the character of the propagating structures directed at an inclined angle to the direction of flow. Where the disturbance increases the amplitudes of the propagating structure, turbulent mixing or heating is increased; and when the disturbance decreases the amplitude of the propagating structure, the turbulent drag is decreased.