Multi-section blade with cooling for turbomachinery

Abstract

Multi-part blade (1) with cooling for turbomachinery, comprising a blade body (2) with a cavity (3) and a cooling channel insert (4) received within the cavity (3), wherein the cooling channel insert (4) has a cooling channel (5) with a coolant supply (5a) and a coolant discharge (5e) in the region of a blade root (1a), a first cooling channel path (5b) inside the cooling channel insert (4), a second cooling channel path (5d) spirally or mantle-like surrounding the first cooling channel path (5b) in a surface of the cooling channel insert (4) and a cooling channel deflection (5c) in the region of a blade tip (1b), and the blade body (2) and the cooling channel insert (4) are assembled by means of a first fastening connection (7).

Description

Technical field

[0001] The present invention relates to a multi-part blade, in particular a guide blade or a rotor blade with cooling for turbomachinery, in particular for a compressor or for a turbine. State of the art

[0002] In turbomachinery, various blades with different interactions with the fluid flowing through the machine are used. A distinction is made between guide vanes on the casing and rotor blades on the impeller. The guide vanes are positioned on the turbomachine casing and direct the fluid onto the rotor blades. Depending on the application, whether the machine is a driven machine or a power machine, the rotor blades convert fluid energy into rotational energy. The blades are subjected to significant thermal stress, which is counteracted by the use of cooling systems.

[0003] German patent DE 879 485 B discloses a turbine blade, in particular a rotor blade with evaporative cooling, which is provided with an annular channel inside. The blade cavity is divided longitudinally into two channels by a partition wall curved according to the blade profile. The two longitudinally extending channels are connected to each other at the tip and root of the blade. The annular channel is closed, so that a cooling circuit with evaporation and condensation is formed within the blade. The circuit is driven by centrifugal force. Condensation takes place via a finned heat exchanger at the root of the blade, which is cooled by air. The turbine blade is assembled from several welded sheets.

[0004] From German patent application DE 10 2015 203 175 A1, a guide vane or rotor assembly is known which is cast from a metal alloy and comprises at least one blade platform and a blade formed integrally with the blade platform. A cavity extends from the blade platform to the tip of the blade, and this cavity is divided into chambers by at least one partition wall located in the area of ​​the blade and extending between two opposing outer walls of the blade.

[0005] From patent application WO 2013 138 129 A1, a blade for a gas turbine engine is known which includes a cooling circuit within the blade body. Guide elements are provided in the cooling circuit to improve the distribution of the coolant and thus the heat transfer, particularly at the blade tip.

[0006] US Patent 1,966,104 A discloses cooled turbine blades for a turbine rotor in which the turbine blades are multi-part and incorporate an internal cooling channel arrangement. The turbine blade consists of a core section with integrated longitudinal channels that guide a cooling medium from the interior of the rotor disk into the core section and back again. These channels are closed at their outer ends by welded screw plugs, which provide a channel deflection. A thin-walled, heat-resistant jacket surrounds the core section, keeping hot gases away from the cooled core and thus reducing heat transfer. The jackets are fixed either by a blade ring or by spot welds and are only rigidly connected at one point to allow for thermal expansion.

[0007] Air-cooled turbine blades are known from US patent 2,779,565 A. The turbine uses an air-cooling system in which cooling air enters the rotor through the hollow main shaft. There, the air is forced radially outward by centrifugal force and cooling fins. The air flows through bores into the hollow turbine blades. Between the blade holder and the blade shroud, the air absorbs heat and cools the blades. To improve heat transfer, fins are arranged on the inside of the blade shroud. The heated air flows back through return openings into the exhaust chamber and exits the rotor.

[0008] From patent application WO 2013 182 381 A1, a coolant bypass line for a gas turbine is known, which can be inserted into a hollow, cooled turbine blade and has inner and outer surfaces separated by a wall. The coolant bypass line extends from a first component of the gas turbine to a second component. The coolant bypass line has turbulators that modify the heat transfer between the inner and outer surfaces and is coated with a ceramic material.

[0009] The production of cooling channels and additional guide vanes within the cooling channels of blades for turbomachinery involves a high level of technical effort. Object of the invention

[0010] The object of the invention is to provide an advantageous blade with cooling for turbomachinery, in which the manufacture of a cooling channel is simplified. Solution to the task

[0011] The problem is solved by an advantageous multi-part blade with cooling for turbomachinery according to the features of claim 1, which is simplified with regard to the manufacture of a cooling channel. Advantageous further developments are described in the dependent claims and the exemplary embodiments. Description of the invention

[0012] The invention provides an advantageous multi-part blade with cooling for turbomachinery, in which the manufacture of a cooling channel, particularly with guide vanes, is simplified. For this purpose, the blade is designed in multiple parts, comprising a blade body and a cooling channel insert. A cavity is provided in the blade body into which the cooling channel insert is placed. This allows for the simple manufacture of the blade body and the cooling channel insert, as well as their subsequent assembly. The cooling channel insert has at least one cooling channel with a coolant inlet and a coolant outlet. In an advantageous further development, the cooling channel is at least partially equipped with guide vanes. The guide vanes enhance heat transfer between the blade body and the coolant through fluid dynamic effects.The cooling channel is designed in such a way that liquid cooling, in particular liquid cooling with at least partial evaporation of a coolant, is possible.

[0013] Advantageously, the cavity in the blade body is designed as a simple bore, and the cooling channel insert as a corresponding elongated cooling channel insert. The cavity and the cooling channel insert extend from the blade root to near the blade tip, into the area subject to the highest thermal stress. Evaporative cooling is preferably provided in this area of ​​highest thermal stress.

[0014] The cooling channel within the cooling duct runs primarily longitudinally. The cooling channel further comprises a first cooling channel path, a cooling channel deflection near the blade tip, and a second cooling channel path. The first cooling channel path is connected to the coolant supply and the cooling channel deflection. The second cooling channel path is connected to the cooling channel deflection and the coolant outlet.

[0015] In a particularly advantageous embodiment according to the invention, one cooling channel path is located internally, and in particular centrally internally, within the cooling channel insert, and another cooling channel path is located externally in a surface of the cooling channel insert. Evaporative cooling is preferably provided in the external cooling channel path. By inserting the cooling channel insert into the blade body, the external cooling channel path, which is located in the surface of the cooling channel insert, is enclosed on its outer side, so that it is permeable to flow in the longitudinal direction. In a particularly advantageous embodiment, the external cooling channel path is arranged coaxially with the internal cooling channel path, with the external cooling channel path surrounding the internal cooling channel path. According to the invention, the external cooling channel path is designed in a jacket-like or spiral shape. Guide vanes are positioned in the external cooling channel path to further improve heat dissipation.

[0016] The first cooling channel is located centrally inside the cooling channel insert, while the second cooling channel is routed along a surface of the insert. The second cooling channel is coaxial with the first, surrounding it. The second cooling channel is shaped like a jacket or spiral. Guide vanes are positioned within the second cooling channel.

[0017] The spiral shape increases heat transfer between the blade body and the coolant through fluid dynamics. Furthermore, the resulting centrifugal force separates the vapor and liquid phases in the coolant, thus promoting wetting of the hot walls.

[0018] The blade body and the cooling channel insert have a first fastening connection by means of which the cooling channel insert is inserted and secured in the cavity of the blade body. This first fastening connection is designed as a material-fit connection, a force-fit connection, and / or a positive-fit connection. The first fastening connection is preferably located in the area of ​​the blade tip. Alternatively, the first fastening connection is located in the area of ​​the blade root. Preferably, the first fastening connection is designed as a screw connection.

[0019] In a particularly outstanding manner according to the invention, the cooling channel insert is designed as a fastening element for attaching the blade to the blade carrier. The blade carrier has an opening through which the cooling channel insert extends to secure the blade body to the blade carrier. In the case of a blade designed as a guide vane, the housing is designed as the blade carrier, so that the guide vane is attached to the housing by means of the cooling channel insert. In the case of a blade designed as a rotor blade, the rotor is designed as the blade carrier, so that the rotor blade is attached to the rotor by means of the cooling channel insert.Advantageously, the blade body is attached to the blade carrier by means of the cooling channel insert in the form of a pull-in connection, wherein the cooling channel insert is inserted through the opening in the blade carrier from a side of the blade carrier facing away from the blade body and then connected to the blade body. Alternatively, the attachment is designed as a pin connection, in which the cooling channel insert is connected to the blade body, inserted through an opening in the blade carrier from a side of the blade carrier facing towards the blade body, and then secured to the blade carrier with an additional fastening element from the side of the blade carrier facing away from the blade body.

[0020] The first fastening connection is designed for either a pull-in or a pin connection. The attachment of the blade body to the blade carrier via the pull-in connection is therefore achieved by means of the cooling channel insert, by creating the first fastening connection.

[0021] Advantageously, the first fastening connection is designed as a positive-locking connection, in particular as a screw connection, wherein a first internal thread is provided in the cavity of the blade base body and a corresponding first external thread is provided on the cooling channel insert.

[0022] The cooling channel insert and an additional fastening element feature a second fastening connection by means of which the cooling channel insert, and thus the entire blade, is attached to the blade carrier. This second fastening connection is designed as a material-fit connection, a force-fit connection, and / or a positive-fit connection. The second fastening connection is located in the area of ​​the blade root. The second fastening connection is designed for a pin connection. The attachment of the blade body to the blade carrier in the pin connection manner is therefore achieved by means of the cooling channel insert, by creating the first and second fastening connections.

[0023] Advantageously, the second fastening connection is designed as a positive-locking connection, in particular as a screw connection, wherein a second internal thread is provided in the cooling channel insert and the additional fastening element is designed as a threaded screw, or a second external thread is provided on the cooling channel insert and the additional fastening element is designed as a threaded nut.

[0024] The material of the blade body and the cooling channel insert of the multi-section blade differs advantageously. The materials are selected according to the respective requirements in order to meet the prevailing loads. Example 1

[0025] An advantageous embodiment of a multi-part blade (1) with cooling for turbomachinery according to the invention is shown here by way of example. The accompanying figure shows: Fig. 1 a schematic representation of the blade (1) with cooling for turbomachinery.

[0026] The advantageous embodiment of the multi-part blade (1) according to the invention with cooling, illustrated in Fig. 1, has a blade body (2) with a cavity (3) and a cooling channel insert (4) located within the cavity (3). The cavity (3), designed as a simple bore, and the cooling channel insert (4) corresponding to the cavity (3) extend from the blade root (1a) to the blade tip (1b) in the area subject to the highest thermal stress.

[0027] The cooling channel insert (4) has at least one cooling channel (5) with a coolant inlet (5a) in the region of the blade root (1a), a first cooling channel path (5b) extending longitudinally along the blade (1), a cooling channel deflection (5c) in the region of the blade tip (1b), a second cooling channel path (5d) extending mainly longitudinally along the blade (1), and a coolant outlet (5e) in the region of the blade root (1a). The centrally located first cooling channel path (5b) is connected to the coolant inlet (5a) and the cooling channel deflection (5c). The second cooling channel path (5d), which spirally surrounds the first cooling channel path (5b), is connected to the cooling channel deflection (5c) and the coolant outlet (5e). The second cooling channel path (5d) is guided along a surface of the cooling channel insert (4).

[0028] Furthermore, the cooling channel insert (4) is designed as a fastening element to attach the blade (1) to a blade carrier (6) in the sense of a pull-in connection. The fastening is effected through an opening (6a) in the blade carrier (6), wherein the cooling channel insert (4) extends from a side of the blade carrier (6) facing away from the blade body (2) through the opening (6a) in the blade carrier (6) into the cavity (3) in the blade body (2) and is designed as a hollow screw with the cooling channel.

[0029] The blade body (2) and the cooling channel insert (4) have a first fastening connection (7) as a positive-locking connection, in particular as a screw connection, wherein a first internal thread (7a) is provided in the cavity (3) of the blade body (2) and a corresponding first external thread (7b) is provided on the cooling channel insert (4). The fastening of the blade body (2) to the blade carrier (6) in the sense of a pull-in connection is effected by means of the cooling channel insert (4), by extending the cooling channel insert through the opening (6a) in the blade carrier (6) and screwing it into the cavity (3) in the blade body (2), thus establishing the first fastening connection. Example 2

[0030] An alternative advantageous embodiment of a multi-part blade (1) with cooling for turbomachinery according to the invention is shown here by way of example. The accompanying figure shows:

[0031] Fig. 2 a schematic representation of the blade (1) with cooling for turbomachinery.

[0032] The alternative advantageous embodiment of the multi-part blade (1) according to the invention with cooling, illustrated in Fig. 2, has a second cooling channel path (5d) extending mainly in the longitudinal direction of the blade (1), which surrounds the first cooling channel path (5b) in a mantle-like manner. The second cooling channel path (5d) is connected to the cooling channel deflection (5c) and the coolant discharge (5e) and is guided on a surface of the cooling channel insert (4). Guide vanes (8) are arranged within the second cooling channel path (5d). List of reference symbols used 1, 1a, 1b shovel, shovel foot, shovel tip 2 shovel bodies 3 cavities 4 Cooling channel insert 5 Cooling channel 5a, 5e Coolant supply, coolant discharge 5b, 5d first cooling channel path, second cooling channel path 5c Cooling channel deflection 6, 6a Shovel carrier, opening 7, 7a, 7b first fastening connection, first internal thread, first external thread

Claims

[1] Multi-part blade (1) with cooling for turbomachinery, comprising a blade body (2) with a cavity (3) and a cooling channel insert (4) received within the cavity (3), wherein the cooling channel insert (4) has a cooling channel (5) with a coolant supply (5a) and a coolant discharge (5e) in the region of a blade root (1a), a first cooling channel path (5b) inside the cooling channel insert (4), a second cooling channel path (5d) in a surface of the cooling channel insert (4) which surrounds the first cooling channel path (5b) in a spiral or mantle-like manner, and a cooling channel deflection (5c) in the region of a blade tip (1b), and the blade body (2) and the cooling channel insert (4) are assembled by means of a first fastening connection (7). [2] Multi-part blade (1) with cooling for turbomachinery according to claim 1, characterized by, that the first fastening connection (7) is designed as a screw connection, wherein a first internal thread (7a) is provided in the cavity (3) of the blade base body (2) and a corresponding first external thread (7b) is provided on the cooling channel insert (4). [3] Multi-part blade (1) with cooling for turbomachinery according to one of the preceding claims, characterized by , that the cooling channel insert (4) is designed as a fastening element to attach the blade (1) to a blade carrier (6), wherein the cooling channel insert (4) extends through an opening (6a) in the blade carrier (6).

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