Repair method for turbine blades
Disclosed is a repair method for guide blades of a gas turbine. The method comprises: providing at least one guide blade to be maintained; capturing the actual geometry of the guide blade to be maintained with application of at least one measuring method; comparing the actual geometry captured by the contactless measuring method to a predetermined desired geometry for a corresponding guide blade type; calculating a target geometry for the guide blade to be maintained, which corresponds as much as possible to the desired geometry, such that using optimization parameters, the desired geometry of the guide blade to be maintained is approximated at least in sections along its flow contour; applying material and removing material by machine on the guide blade, such that the calculated target geometry is produced.
1 . A method for repairing worn guide blades of a gas turbine, the method consisting of the steps of:
providing at least one worn guide blade to be repaired; the at least one worn guide blade having an original state with an original geometry prior to use in the gas turbine and an actual worn state after use in the gas turbine;
capturing a desired geometry of the at least one worn guide blade; the desired geometry being an approximation of the original geometry;
capturing an actual geometry of the at least one worn guide blade to be repaired in the actual worn state prior to any subsequent processing of the at least one worn guide blade using at least one contactless measuring method;
comparing the actual geometry of the at least one worn guide blade captured by the at least one contactless measuring method to the desired geometry for a corresponding guide blade type;
calculating a target geometry for the at least one worn guide blade to be repaired, which corresponds as closely as possible to the desired geometry, such that using optimization parameters, the desired geometry of the at least one worn guide blade to be repaired is approximated at least in sections along its flow contour;
applying material on the at least one worn guide blade to be repaired and subsequently removing excess applied material by machine, such that the calculated target geometry is produced to provide an at least one repaired guide blade;
the target geometry of the at least one worn guide blade to be repaired being calculated and reestablished wherein a flow contour in a region of an A4 cross section of the at least one repaired guide blade approximates a flow contour of the desired geometry in the region of the A4 cross section, the A4 cross section being located along a connecting line between a rear edge region of a pressure side of a first guide blade and a central region of a suction side of an adjacent second guide blade.
2 . The method for repairing worn guide blades of a gas turbine of claim 1 , wherein application and removal of material are performed along a suction side of a flow contour of the at least one worn guide blade from a front edge up to a rear edge of the guide blade.
3 . The method for repairing worn guide blades of a gas turbine of claim 1 , wherein removal of excess applied material is carried out by automated milling and/or grinding.
4 . The method for repairing worn guide blades of a gas turbine of claim 1 , wherein application of material is performed by soldering.
5 . The method for repairing worn guide blades of a gas turbine of claim 4 , wherein application of material is performed by diffusion soldering.
6 . The method for repairing worn guide blades of a gas turbine of claim 1 , wherein application of material is carried out as a function of the actual geometry and the target geometry.
7 . The method for repairing worn guide blades of a gas turbine of claim 1 , wherein after application of material to the at least one guide blade, a further calibration is carried out to position the at least one guide blade for removal of excess applied material.
8 . The method for repairing worn guide blades of a gas turbine of claim 1 , wherein the desired geometry is an approximation to a geometry of the guide blade in like-new condition.
9 . The method for repairing worn guide blades of a gas turbine of claim 1 , wherein the desired geometry is a geometry of the guide blade in like-new condition.
10 . The method for repairing worn guide blades of a gas turbine of claim 8 , wherein the desired geometry is determined by a measuring method which is carried out on a guide blade in like-new condition.
11 . The method for repairing worn guide blades of a gas turbine of claim 9 , wherein the desired geometry is derived from design data of a guide blade.
12 . The method for repairing worn guide blades of a gas turbine of claim 1 , wherein the provided guide blade is taken from a high-pressure turbine.
13 . The method for repairing worn guide blades of a gas turbine of claim 1 , wherein the at least one worn guide blade is taken from a first high-pressure turbine stage, which directly adjoins a combustion chamber.
14 . The method for repairing worn guide blades of a gas turbine of claim 1 , wherein the steps of the method are carried out repeatedly until all guide blades of a guide blade ring of a turbine stage are repaired.
15 . The method for repairing worn guide blades of a gas turbine of claim 14 , wherein the turbine stage is a high pressure turbine stage.
16 . The method for repairing worn guide blades of a gas turbine of claim 1 , wherein the method is carried out by using a repair system for worn turbine blades of a gas turbine, which the system comprises;
at least one receptacle unit, which is configured to hold the at least one worn turbine blade to be repaired;
at least one contactless measuring device, which is configured to capture the geometry of the worn turbine blade to be repaired;
at least one automatic processing device, which is configured to apply the material to the worn turbine blade to be repaired and to remove excess applied material;
at least one computer unit, which is configured to
control the measuring device and/or the processing device,
store a corresponding turbine type of the desired geometry in an assigned memory,
calculate the target geometry on the basis of optimization parameters and based on the comparison of the actual geometry and the desired geometry, and
control the processing device such that the target geometry of the worn turbine blade to be repaired is reestablished in at least the A4 cross section with reference to the calculated optimization parameters.
17 . The method for repairing worn guide blades of a gas turbine of claim 1 , wherein the at least one worn guide blade is a part of a guide blade segment or ring that has multiple guide blades connected to one another.
18 . The method for repairing worn guide blades of a gas turbine of claim 17 , wherein the multiple guide blades are integrally connected to each other.
19 . The method for repairing worn guide blades of a gas turbine of claim 17 , wherein individual optimization parameters are calculated based on a capture of an actual geometry for each guide blade of the guide blade segment or ring.