Cooled gas turbine guide blade for a gas turbine, use of a gas turbine guide blade and method for operating a gas turbine

Abstract

Described is a cooled gas turbine guide blade for a gas turbine, with a hollow blade profile which comprises an onflow edge onto which a working medium is capable of flowing, and with, for guiding a cooling medium, an onflow edge duct running inside the blade profile along the onflow edge. Furthermore, to the use of such a gas turbine guide blade and to a method for operating a gas turbine with an abovementioned gas turbine guide blade. In order to provide a gas turbine guide blade with an increased lifetime by means of the invention, it is proposed that, in the onflow edge duct, an electrical heating element be provided, which extends approximately completely over the entire length of the onflow edge duct and through which a heating current flows, before the operation of the gas turbine, for the preheating of the gas turbine guide blade.

1 . A method for operating a gas turbine engine, comprising:
 preheating a guide blade of the gas turbine engine by providing a heat input to the guide blade before a start-up operation of the gas turbine engine;   initiating the start-up operation of the gas turbine engine;   adjusting the heat input to the guide blade during a normal operating state of the gas turbine engine; and   adjusting the heat input to the guide blade during a shutdown operation of the gas turbine engine.   
   
   
       2 . The method as claimed in  claim 1 , wherein the heat input to the guide blade is varied during the start-up operation. 
   
   
       3 . (The method as claimed in  claim 2 , wherein the heat input to the guide blade is increased during the start-up operation 
   
   
       4 . The method as claimed in  claim 3 , wherein the heat input to the guide blade is constant during the start-up operation. 
   
   
       5 . The method as claimed in  claim 1 , wherein the heat input to the guide blade is decreased during the normal operation. 
   
   
       6 . The method as claimed in  claim 5 , wherein the heat input to the guide blade is constant during the normal operation. 
   
   
       7 . The method as claimed in  claim 1 , wherein the guide blade is reheated after the shutdown operation of the gas turbine engine.