Turbine Blade

Abstract

A turbine blade, having a plurality of auxiliary cooling channels which branch off from a main cooling channel, formed within a blade body, is provided. The plurality of auxiliary cooling channels open into outlet openings in the leading edge region of the blade body. A heat shield element is attached to the blade body in the leading edge region at a predefined spacing, wherein the heat shield element has a number of outlet channels which are arranged behind one another in the longitudinal direction and extend from the main cooling channel to the outer wall face of the heat shield element.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is the US National Stage of International Application No. PCT / EP2007 / 059989, filed Sep. 20, 2007 and claims the benefit thereof. The International Application claims the benefits of European Patent Office application No. 06022622.2 EP filed Oct. 30, 2006, both of the applications are incorporated by reference herein in their entirety.FIELD OF INVENTION[0002]The invention refers to a turbine blade according to the claims.BACKGROUND OF INVENTION[0003]Turbomachines, especially gas turbines, are used in many areas for driving generators or driven machines. A gas turbine customarily has a rotatably mounted rotor which is enclosed by a fixed casing. The fixed sub-assemblies of a gas turbine are also collectively referred to as a stator. The energy content of a fuel in this case is used for producing a rotational movement of the rotor components. For this purpose, the fuel is combusted in a combustion chamber, wherein compressed...

AI Technical Summary

Benefits of technology

[0008]In order to enable an especially uniform and effective film cooling in the leading edge region of the blade airfoil, the discharge openings in this region are customarily arranged uniformly along at least two rows which are oriented parallel to the leading edge. The discharge passages, moreover, as a rule are oriented at an angle to the longitudinal direction of the turbine blade, which assists the forming of the protective cooling air film which flows along the surface.

[0027]The advantages which are achieved with the invention are especially that by means of the heat shield element which is connected upstream to the blade basic body of the turbine blade an efficient protection of the leading edge region of the turbine blade against the high temperatures of the operating medium of the turbines is provided. In particular, such a heat shield system enables the use of impingement cooling, as a result of which the heat shield element can be cooled in an especially effective manner. Furthermore, by means of the heat shield element the possible occurrence of cracks, which extend from the outside surface of the heat shield element and spread into the blade basic body, is prevented. Moreover, the heat shield elements according to the invention can subsequently be attached on the turbine blades in a simple manner and with relatively little cost.

Problems solved by technology

This heat shield, however, has the disadvantage that after a certain time cracks occur in the heat shielding coating.

These cracks reduce the protection of the blade basic body against the hot exhaust gas of the gas turbine so that as a consequence of the increased thermal stress crack development can also occur in the basic body of the turbine blade.

Such cracks in the blade basic body endanger the operational safety and can lead to the breakdown of the gas turbine.

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