Refrigerant powered valve for a geothermal power plant

Abstract

A vapor expansion system includes a normally closed pneumatic valve between the evaporator and the turbine inlet, with the valve being selectively actuated by the flow of refrigerant vapor from the evaporator so as to enable opening the valve only during periods in which sufficient pressure has built up in the evaporator to properly operate the turbine. A bypass line has a normally open pneumatic valve with an actuator that is similarly caused to operate by pressurized refrigerant vapor from the evaporator. Both actuators are vented to the condenser such that the refrigerant vapor vented from the actuator does not escape to ambient.

1 . A vapor expansion system of the type having in serial flow relationship a turbine, a condenser, a pump and an evaporator, comprising:
 a pneumatically actuated valve with an actuator moveable to a position for fluidly connecting the evaporator to a turbine inlet by way of said valve;   a conduit which fluidly interconnects said evaporator to said actuator such that pressurized refrigerant from said evaporator is selectively caused to move said actuator to open said pneumatically actuated valve.   
     
     
         2 . A vapor expansion system as set forth in  claim 1  wherein said pneumatically actuated valve is a normally closed valve. 
     
     
         3 . A vapor expansion system as set forth in  claim 1  wherein said actuator includes a vented section and said vented section is fluidly connected to said condenser. 
     
     
         4 . A vapor expansion system as set forth in  claim 1  and including a pressure regulator between said evaporator and said actuator so as to provide pressurized refrigerant to said actuator at a predetermined pressure level. 
     
     
         5 . A vapor expansion system as set forth in  claim 1  and including a solenoid valve fluidly connected between said evaporator and said actuator. 
     
     
         6 . A vapor expansion system as set forth in  claim 5  wherein solenoid valve is a three way valve with a vent port being fluidly connected to the condenser. 
     
     
         7 . A vapor expansion system as set forth in  claim 1  wherein said actuator includes a spring for biasing a sliding piston in position. 
     
     
         8 . A vapor expansion system as set forth in  claim 1  wherein said actuator is of the rack-and-pinion type. 
     
     
         9 . A vapor expansion system as set forth in  claim 1  and including a bypass line for conducting the flow of refrigerant vapor around said turbine and to said condenser said bypass line having a pneumatic valve disposed therein. 
     
     
         10 . A vapor expansion system as set forth in  claim 9  wherein said pneumatic valve is a normally open valve with an actuator fluidly connected to said evaporator. 
     
     
         11 . A method of controlling a vapor expansion system of the type having in serial flow relationship a turbine, a condenser, a pump and an evaporator, comprising the steps of:
 providing a pneumatically actuated valve with an actuator moveable to a position for fluidly connecting the evaporator to a turbine inlet by way of said valve;   fluidly interconnecting said evaporator to said actuator such that pressurized refrigerant from said evaporator is selectively caused to move said actuator to open said pneumatically actuated valve.   
     
     
         12 . A method as set forth in  claim 11  wherein said pneumatically actuated valve is a normally closed valve. 
     
     
         13 . A method as set forth in  claim 11  wherein said actuator includes a vented section and including the step of connecting said vented section to said condenser. 
     
     
         14 . A method as set forth in  claim 11  and including the steps of providing a pressure regulator between said evaporator and said actuator and providing pressurized refrigerant to said actuator at a predetermined pressure level. 
     
     
         15 . A method as set forth in  claim 11  and including the step of connecting a solenoid valve fluidly between said evaporator and said actuator. 
     
     
         16 . A method as set forth in  claim 15  wherein solenoid valve is a three way valve with a vent port and including the step of fluidly connecting said vent to the condenser. 
     
     
         17 . A method as set forth in  claim 11  wherein said actuator includes a spring for biasing a sliding piston in position. 
     
     
         18 . A vapor expansion system as set forth in  claim 11  wherein said actuator is of the rack-and-pinion type. 
     
     
         19 . A method as set forth in  claim 1  and including the step of providing a bypass line for conducting the flow of refrigerant vapor around said turbine and to said condenser by way of a pneumatic valve. 
     
     
         20 . A method as set forth in  claim 19  wherein said pneumatic valve is a normally open valve and including the step of fluidly connecting said actuator to said evaporator.