Pressure relief of a flange connection in overflow lines between a live steam valve and a high-pressure steam turbine inlet

Abstract

A steam turbine ( 1 ) having an upper housing part ( 4 ) and a lower housing part ( 5 ), in which the steam turbine ( 1 ) has at least one overflow line ( 18 ) between a live steam adjusting valve ( 8, 9 ) and a high-pressure steam turbine inlet, and the valve housing ( 14 ) of the live steam adjusting valve ( 8, 9 ) communicates with the overflow line ( 18 ) via a flange connection ( 27 ), and a live steam pipe ( 25 ) in the live steam adjusting valve ( 8, 9 ) is provided as a steam duct between the valve housing ( 14 ) and the overflow line ( 18 ), and a sealing element ( 19 ) is disposed between the live steam pipe ( 25 ) and a sealing seat ( 28 ) in the overflow line ( 18 ), is distinguished in that an annular chamber ( 24 ) between the live steam pipe ( 25 ) and the valve housing ( 14 ) is provided with a pressure relief line ( 21 ) into a chamber of lower pressure than the live steam pressure. As a result, an improved steam turbine with pressure relief of flanges in overflow lines between live steam adjusting valves and high-pressure steam turbine inlets is made available, and as a result the flange connections are lighter in weight and embodied with greater thermal elasticity.

1 . A steam turbine having an upper housing part and a lower housing part, in which the steam turbine has at least one overflow line between a live steam adjusting valve and a high-pressure steam turbine inlet, and the valve housing of the live steam adjusting valve communicates with the overflow line via a flange connection, and a live steam pipe in the live steam adjusting valve is provided as a steam duct between the valve housing and the overflow line, and a sealing element is disposed between the live steam pipe and a sealing seat in the overflow line, 
 wherein    an annular chamber between the live steam pipe and the valve housing is provided with a pressure relief line into a chamber of lower pressure than the live steam pressure.    
   
   
       2 . The steam turbine of  claim 1 , wherein the pressure relief line communicates with an exhaust steam conduit of the high-pressure turbine.  
   
   
       3 . The steam turbine of  claim 1 , wherein the sealing elements are embodied as piston rings.  
   
   
       4 . The steam turbine of  claim 1 , wherein the pressure relief line is embodied in the flange connection.  
   
   
       5 . The steam turbine of  claim 1 , wherein the pressure relief line is provided for a valve housing with an inserted diffusor.  
   
   
       6 . The steam turbine of  claim 1 , wherein the pressure relief line is provided for a valve housing with a diffusor and a bell.  
   
   
       7 . The steam turbine of  claim 1 , wherein the flange connection is designed for a temperature difference of 500° C. to 700° C., preferably for a temperature difference of 550° C. to 600° C.  
   
   
       8 . The steam turbine of  claim 1 , wherein the flange connection is designed for a temperature difference greater than or equal to 700° C.