Steam turbine clutch and method for disengagement of steam turbine from generator

Abstract

A power generation system including: at least one elevated steam turbine receiving input steam at an elevated pressure and exhausting steam as low pressure steam; a low pressure steam turbine receiving low pressure steam exhausted from the elevated steam turbine, and a drive shaft for the low pressure steam turbine connected to a clutch which is reasonably coupled to a power generator, wherein the clutch has a first position in which power from the low pressure steam turbine is applied to the power generator and a second position in which power from the low pressure steam turbine is not applied to the generator.

1 . A power generation system comprising:
 at least one elevated steam turbine receiving input steam at an elevated pressure and exhausting steam as low pressure steam;   a low pressure steam turbine receiving low pressure steam exhausted from the elevated steam turbine, and   a drive shaft for the low pressure steam turbine connected to a clutch which is reasonably coupled to a power generator, wherein the clutch has a first position in which power from the low pressure steam turbine is applied to the power generator and a second position in which power from the low pressure steam turbine is not applied to the generator.   
   
   
       2 . The power generation system in  claim 1  further comprising a first low pressure steam valve in a conduit for low pressure steam flowing to the low pressure steam turbine and a second low pressure steam valve in a conduit for low pressure steam flowing to a steam process extraction device, wherein the first low pressure steam valve is open while the second low pressure steam valve is closed, and the first low pressure steam valve is closed while the second low pressure steam valve is open. 
   
   
       3 . The power generation system in  claim 1  wherein the low pressure steam turbine includes a first low pressure steam turbine, and a second low pressure steam turbine and the clutch engages and disengages the second low pressure steam turbine from the first low pressure steam turbine, and the first low pressure steam turbine is coupled to the generator. 
   
   
       4 . The power generation system in  claim 3  further comprising a first low pressure steam valve in a conduit for the low pressure steam flowing to the second low pressure steam turbine, wherein the first low pressure steam valve is open while the clutch engages the second low pressure steam turbine to the first low pressure steam turbine, and the first low pressure steam valve is closed while the clutch disengages the second low pressure steam turbine from the first low pressure steam turbine. 
   
   
       5 . The power generation system as in  claim 4  wherein the first valve is an isolation valve. 
   
   
       6 . The power generation system as in  claim 1  wherein the at least one elevated steam turbine includes a high pressure steam turbine receiving high pressure steam and an intermediate steam turbine receiving steam exhausted from the high pressure steam turbine, wherein steam exhausted from the intermediate steam turbine is applied as the low pressure steam for the low pressure steam turbine. 
   
   
       7 . The power generation system as in  claim 1  wherein the clutch is a planetary clutch. 
   
   
       8 . The power generation system as in  claim 1  wherein the first position of the clutch is an open position and the second position of the clutch is a closed position. 
   
   
       9 . A power generation system comprising:
 a high pressure steam turbine receiving high pressure steam and exhausting steam at an intermediate pressure;   an intermediate steam turbine receiving steam exhausted from the high pressure steam turbine and exhausting low pressure steam;   a low pressure steam turbine receiving low pressure steam exhausted from the intermediate steam turbine, and   a drive shaft for the low pressure steam turbine connected to a clutch and the clutch is releasably coupled to a power generator, wherein the clutch has a first position in which power from the low pressure steam turbine is applied to the power generator and a second position in which power from the low pressure steam turbine is not applied to the generator.   
   
   
       10 . The power generation system in  claim 9  further comprising a first low pressure steam valve in a conduit for low pressure steam flowing to the low pressure steam turbine and a second low pressure steam valve in a conduit for low pressure steam flowing to a steam process extraction device, wherein the first low pressure steam valve is open while the second low pressure steam valve is closed, and the first low pressure steam valve is closed while the second low pressure steam valve is open. 
   
   
       11 . The power generation system in  claim 10  wherein the low pressure steam turbine includes a first low pressure steam turbine and a second low pressure steam turbine, and the clutch engages and disengages the second low pressure steam turbine from the first low pressure steam turbine. 
   
   
       12 . The power generation system in  claim 11  further comprising a first low pressure steam valve in a conduit for the low pressure steam flowing to the second low pressure steam turbine, wherein the first low pressure steam valve is open while the clutch engages the second low pressure steam turbine to the first low pressure steam turbine, and the first low pressure steam valve is closed while the clutch disengages the second low pressure steam turbine. 
   
   
       13 . The power generation system in  claim 9  wherein the drive shaft is coupled to a drive shaft for the high pressure steam turbine and a drive shaft for the low pressure steam turbine. 
   
   
       14 . A method for power generation using a generator, an elevated pressure steam turbine, a low pressure steam turbine and a clutch coupled to a drive shaft of the low pressure steam turbine, the method comprising:
 applying low pressure steam to the low pressure steam turbine;   driving the generator by the low pressure steam turbine while the clutch is closed, and   opening the clutch to disengage the low pressure steam turbine from the generator.   
   
   
       15 . The method in  claim 14  further comprising terminating the application of low pressure steam to the low pressure steam turbine while the clutch is open. 
   
   
       16 . The method in  claim 14  further comprising closing a first valve to terminate the application of low pressure steam to the low pressure steam turbine and opening a second valve to direct low pressure steam to an external process, wherein the first valve is closed and the second valve is open while the clutch is open. 
   
   
       17 . The method as in  claim 14  wherein the low pressure steam turbine is a first low pressure steam turbine and the method further comprises:
 applying low pressure steam to the second low pressure steam turbine during the application of low pressure steam to the first low pressure steam turbine;   driving the generator by the second low pressure steam turbine in addition to the driving of the generator by the first low pressure steam turbine, and   continuing to drive the generator by the second low pressure steam turbine, while the clutch is open.   
   
   
       18 . The method as in  claim 17  wherein the opening of the clutch disengages a drive shaft for the first low pressure steam turbine from a drive shaft for the second low pressure steam turbine. 
   
   
       19 . The method as in  claim 14  further comprising applying elevated pressure steam to an elevated pressure steam turbine and driving the generator with the elevated pressure steam turbine while the clutch is open. 
   
   
       20 . The method as in  claim 14  further comprising, after the opening of the clutch, closing the clutch to engage the low pressure steam turbine to drive the generator.