Heat-shield element for a compressor-air bypass around the combustion chamber

Abstract

A heat-shield element ( 14 ), for lining a combustion-chamber wall ( 13 ), the chamber wall has a first wall ( 17 ) with a hot side ( 18 ) which can be loaded with a hot medium, a cold side ( 19 ) which lies opposite the hot side ( 18 ), and a circumferential edge ( 24 ) which extends on a first ( 20 ), a second ( 21 ) and a third narrow side ( 22 ) of the first wall ( 17 ) to a first height ( 25 ) beyond the cold side ( 19 ), the circumferential edge ( 24 ) extends on a fourth narrow side ( 23 ) to a second shorter height ( 26 ), substantially at the second height ( 26 ), a second wall ( 27 ) lies opposite the cold side ( 19 ) and extends over the width of the fourth narrow side ( 23 ) from the fourth narrow side ( 23 ) and over a part of the length of the narrow sides ( 20, 22 ), which adjoin the fourth narrow side; ( 23 ), the second wall ( 27 ) has an edge ( 29 ) at the end ( 28 ) thereof which faces away from the fourth narrow side ( 23 ), which edge ( 29 ) extends to the first height ( 25 ). Furthermore, a combustion chamber and a gas turbine are disclosed.

1 . A heat-shield element for cladding a combustion chamber wall, the element comprising a first wall having a hot side for being exposed to a hot medium, a cold side opposite the hot side; and
 a circumferential edge which extends along a top side of a first, a second and a third narrow side at the cold side of the first wall and the circumferential edge is substantially at a first height above and around the cold side of the first wall, the circumferential edge extends to a second height, shorter than the first height, on a fourth narrow side;   substantially at the second height a second wall lies opposite and spaced above the cold side and extends over the breadth of the fourth narrow side and from the fourth narrow side the second wall extends over part of the length of the narrow sides that are adjacent to the fourth narrow side;   the second wall having an end spaced away from the fourth narrow side and having an edge at the end of the second wall which extends to the first height.   
     
     
         2 . The heat-shield element as claimed in  claim 1 , comprised of a metal or a metal alloy which is capable of withstanding high temperatures. 
     
     
         3 . The heat-shield element as claimed in  claim 1  further comprising a plurality of cold air openings arranged in the circumferential edge. 
     
     
         4 . The heat-shield element as claimed in  claim 3 , wherein the cold air openings are arranged at least in the region of the second wall and between the first and the second wall. 
     
     
         5 . The heat-shield element as claimed in  claim 1 , further comprising an attachment opening, and a surround frame around the attachment opening extends from the first wall to the first height. 
     
     
         6 . A combustion chamber comprising a combustion chamber wall with a burner-side and a turbine-side end, wherein the combustion chamber wall has a circumferential direction and is comprised of a number of the heat-shield elements as claimed in  claim 1 , the heat shield elements are arranged circumferentially in a row at the turbine-side end of the combustion chamber wall and the elements being respectively oriented for forming a first chamber from the first wall to the first height and a second chamber between the first and second walls, and the fourth narrow side is oriented toward the turbine-side end. 
     
     
         7 . The combustion chamber as claimed in  claim 6 , further comprising attachment bolts for attaching the heat-shield elements to the combustion chamber wall. 
     
     
         8 . The combustion chamber as claimed in  claim 6 , further comprising bores introduced into the combustion chamber wall for supplying coolant to the heat-shield elements. 
     
     
         9 . The combustion chamber as claimed in  claim 6  further comprising at least one supply duct per heat-shield element arranged in the combustion chamber wall in the region of the respective second wall, and a plenum which at least partially surrounds the combustion chamber, and the supply duct opens into the plenum. 
     
     
         10 . A gas turbine having a combustion chamber as claimed in  claim 9 , wherein the gas turbine comprises at least one tapping located for receiving compressor air, and which opens into the plenum via at least one line having a valve.