Cooled Turbine Rotor Blade

Abstract

A cooled turbine rotor blade for a gas turbine which is traversed axially by flow and is equipped with an attachment area and an airfoil profile is provided. Meandering cooling channels with interposed deflecting regions are provided in the interior of the airfoil profile. In the deflecting regions, it is possible to prevent dead water regions, which are generated in the prior art, by virtue of at least one of the ribs running so as to curve towards the leading edge or towards the trailing edge in the region of the airfoil tip. At the same time, an opening is provided in the curvature of the rib. Through this opening a part of the coolant flows in the deflecting region and can pass over into the adjacent cooling duct.

Description

[0001]This application is the US National Stage of International Application No. PCT / EP2007 / 056425, filed Jun. 27, 2007 and claims the benefit thereof. The International Application claims the benefits of European application No. 06018490.0 EP filed Sep. 4, 2006, both of the applications are incorporated by reference herein in their entirety.FIELD OF INVENTION[0002]The invention relates to a cooled turbine rotor blade.BACKGROUND OF INVENTION[0003]By way of example, a turbine rotor blade of this generic type and having an airfoil profile is known from EP 0 735 240 A1. A plurality of mutually adjacent cooling channels are provided in order to cool the airfoil profile, are arranged in a meandering shape, and a coolant can flow through them sequentially. The cooling channels in this case each run parallel to the leading edge. Respectively adjacent cooling channels are separated from one another by ribs, with the ribs ending in a direction-reversal area in which the adjacent cooling chan...

AI Technical Summary

Benefits of technology

[0006]The object of the present invention is to provide a turbine rotor blade whose life is further improved.

[0008]The curved rib results in the direction of the cooling air flowing through the cooling channels being changed in a considerably more aerodynamic manner. The direction change is an integral component of the rib, as a result of which the regions with a relatively low flow rate or no flow rate (dead-water regions) in the direction-changing area can be avoided. The flow rate is in consequence kept approximately constant in that cooling channel toward which the rib is curved. However, the curvature of the rib results in an acute-angled corner area in the adjacent cooling channel, in which dead-water regions could now once again occur. In order now to avoid the dead-water regions in the corner area in the adjacent cooling channel, at least one opening is also provided, which is arranged in the curvature and connects the two adjacent cooling channels, and through which a part of the cooling flow can pass over or flow over from one cooling channel into the other cooling channel at an early stage.

[0009]Furthermore, the opening which is arranged in the curved rib can be provided in a particularly simple form. The casting apparatus which is used for casting the turbine rotor blades comprises, in order to produce the cavities through which a coolant can flow, a casting core which has core elements arranged in a meandering shape. In order to support these adjacent core elements, which are arranged in a meandering shape, with respect to one another, a core support can be provided between two adjacent core elements and, after removal of the casting core from the cast, integral turbine blade, leaves behind it the opening within the curved rib. This results in a stabilized casting core which improves the accuracy of the production method.

[0011]In one particularly advantageous refinement, the terminating wall, which is likewise frequently subject to local overheating and is also referred to as a crown base, can also be impingement-cooled on the basis of the coolant jet passing through the opening, in such a way that this likewise makes it possible to cool the terminating wall particularly efficiently. To do this, the opening just has to be inclined such that its longitudinal extent is directed at the terminating wall.

[0012]The rib which is adjacent to the trailing edge is preferably curved in the area of the airfoil tip. In this case, the rib—seen from the attachment area to the tip area—is curved toward the leading edge thus making it possible to provide an essentially constant flow cross-sectional area in a part of the direction-changing area between two adjacent coolant channels. This reduces the pressure losses in the coolant. In order to provide a particularly lightweight turbine rotor blade, the rib has an essentially constant rib thickness along its curvature.

[0013]In one advantageous development of the invention, the inner face of the terminating wall is equipped with turbulators, thus making it possible to improve the cooling of the terminating wall or of the crown base in a simple manner. Depending on the configuration of the turbine rotor blades, it is possible for a coolant to flow sequentially or else in parallel through the adjacent cooling channels. If the flow passes in parallel through the coolant channels, care must be taken to ensure that there is an adequate pressure gradient between them, in order to obtain a coolant flow which passes through the opening.

Problems solved by technology

However, the curvature of the rib results in an acute-angled corner area in the adjacent cooling channel, in which dead-water regions could now once again occur.

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