REPARATURANORDNUNG UND GASTURBINE

Abstract

The invention relates to a repair arrangement for a housing component of a gas turbine, wherein the housing component has at least one crack and at least one torque screw is inserted into the housing component to exert a force on the at least one crack. The invention further relates to a gas turbine having such a repair arrangement.

Claims

1. Repair arrangement for a housing component of a gas turbine, wherein the housing component has at least one crack and at least one torque screw is inserted into the housing component to exert a force on the at least one crack.

2. Repair arrangement according to claim 1, wherein the at least one torque screw is made of stainless steel or nickel-based steel.

3. Repair arrangement according to claim 1, wherein the material of the at least one torque screw has a yield strength which is at least twice the yield strength of the material of the housing component.

4. Repair arrangement according to claim 1, wherein a longitudinal extension direction of the at least one torque screw is substantially perpendicular to a propagation plane of the at least one crack.

5. Repair arrangement according to claim 1, wherein the at least one torque screw is inserted in a borehole of the housing component, which has a receptacle for a screw head of the torque screw.

6. Repair arrangement according to claim 1, wherein the housing component is one housing half of a gas turbine housing.

7. Repair arrangement according to claim 6, wherein the crack extends from a horizontal connecting edge in the installed position of the housing component as far as a second housing half.

8. Gas turbine with a housing component, wherein the housing component has at least one crack and at least one torque screw is inserted into the housing component to exert a force on the at least one crack.

9. Gas turbine with a repair arrangement according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0030] The invention is described in more detail below with reference to the drawing, in which

[0031] FIG. 1 shows a schematic representation of a housing component of a gas turbine with a crack;

[0032] FIG. 2 shows a schematic sectional view of an exemplary embodiment of a repair arrangement according to the invention; and

[0033] FIG. 3 shows a schematic plan view of an exemplary embodiment of a repair arrangement according to the invention.

DETAILED DESCRIPTION

[0034] FIG. 1 shows a housing component 10 for a gas turbine. The housing component 10 is a part of a turbine housing, for example, a housing half, which consists of a ductile cast-iron alloy, preferably spheroidal graphite iron.

[0035] Due to the vibration load during operation of the gas turbine, a crack 12 has formed in the housing component 10, which crack extends away from a connecting flange 14 into the interior of the housing component 10. In the example shown, a crack forms in a plane of the connecting flange 14 which is weakened by boreholes for the bolted connection of the housing components 10.

[0036] For safety reasons, such a damaged housing component 10 must generally be discarded. Nevertheless, in order to allow the safe continued operation of the gas turbine, at least temporarily, further propagation of the crack 12 can be inhibited by means of the repair arrangement 16 shown in FIGS. 2 and 3. In this way, it is at least possible, for example, that such a weakened gas turbine can continue to be operated for one or more maintenance intervals.

[0037] In order to secure the crack 12, a plurality of torque screws 18 are mounted substantially perpendicular to the propagation plane of the crack 12 in the housing component 10. In the interest of clarity, not all such torque screws are shown in the figures.

[0038] The torque screws 18 have a variable force transmission between a screw head 20 and a shaft 22 of the torque screw 18. If a predetermined tightening torque is reached, a connecting element between the screw head 20 and the shaft 22 is released such that the torque screw 18 cannot be tightened further. This allows a well-defined force to be exerted on the crack 12.

[0039] The material of the torque screws 18 has a yield strength that is at least twice the yield strength of the material of the housing component 10.

[0040] This ensures that the torque screw itself does not become deformed on reaching the desired tightening torque, but rather can transfer the set force completely to the material of the housing component 10.

[0041] For example, the yield strength of spheroidal graphite iron is between 310 MPa and 670 MPa. Depending on the alloy used, the yield strength of the torque screw material should therefore be more than 620 MPa and up to more than 1,340 MPa. For example, stainless steel or nickel-based steel may be used for the torque screws 18.

[0042] The torque screws 18 are inserted into boreholes 24 in the housing component 10. These extend far enough from an edge 26 of the housing component 10 that around half of the shaft 22 extends beyond the crack 12, such that a uniform force is exerted on the crack 12.

[0043] The boreholes have a shaft area 28 and a comparatively wider head area 30. The shaft area 28 accommodates the shaft 22 of the torque screws 18, while the head 20 of the torque screws is countersunk into the head area 30 of the boreholes 24. Thus, the head 20 of the torque screws 18 is flush with the edge 26 of the housing component 10.

[0044] As shown in the plan view of FIG. 3, the torque screws 18 are arranged in groups 32. This ensures that a uniform force is exerted over the entire crack 12 and further propagation of the crack is prevented.