This claims the benefit of European Patent Application EP 17152728.6, filed Jan. 23, 2017 and hereby incorporated by reference herein.

The present invention relates to a turbomachine housing element, a turbomachine, especially a gas turbine having the turbomachine housing element, as well as to a method for manufacturing the turbomachine housing element, and to a method for operating the turbomachine.

BACKGROUND

From the German Patent Application DE 10 2010 045 712 B4 of the Applicant, a turbomachine housing is known that is at least partially produced in an additive manufacturing process and that has one or a plurality of control channels in which cooling or heating fluid is circulated to actively control the temperature of the turbomachine housing. The purpose here, namely, is to eliminate the need for a ring between the turbomachine housing and a rotor blade assembly.

SUMMARY OF THE INVENTION

It is an object of an embodiment of the present invention to enhance a turbomachine, especially the manufacture and/or operation thereof.

The present invention provides a turbomachine housing element, a turbomachine having a turbomachine housing element and a method for the manufacture and/or operation thereof.

In an embodiment of the present invention, a turbomachine housing element, namely for a compressor stage or turbine stage of a gas turbine, in fact, at least one turbomachine housing element of a turbomachine, specifically of a compressor stage or turbine stage of a gas turbine, has (at least) one flow channel, in which one or a plurality of rotor blade assemblies is/are accommodated, and, as the case may be, is/are provided, specifically adapted for that purpose. In an embodiment, a rotor blade assembly includes one or a plurality of rotor blades, namely a bladed and rotatably (mounted) rotor.

In an embodiment of the present invention, the turbomachine housing element has (at least) the cavity or one or more of the further cavities, in one variant, at most six of the cavities clarified in greater detail below; in the present case, without limiting generality, the cavity or one of these cavities being referred to as the first cavity and, if indicated, the other as the further cavity or cavities.

In an embodiment of the present invention, the first cavity and, in another embodiment, the or one or more of the further cavities, or the wall thereof is/are produced (in each instance) completely or partially by primary shaping, specifically casting, or especially by an additive manufacturing process, where or in which, in an embodiment, at least the wall; in an embodiment, the complete turbomachine housing element is produced or built up layer by layer by local, namely by chemical and/or physical, more specifically by optical and/or thermal solidification of formless, especially liquid, pasty or loose and, accordingly, bulky, especially pulverant or granular feedstock, more specifically metal, plastic and/or ceramic, and/or by bonding to a subjacent layer, especially by selective laser melting, laser sintering, electron beam melting or the like.

In an embodiment of the present invention, the first and, in another embodiment, the one cavity or more of the further cavities is/are each specifically adapted or used for thermal insulation only, and/or fluid is not actively circulated through this cavity or these cavities in any steady-state and/or transient operating condition (of the turbomachine), specifically not (actively) fed and/or discharged and/or circulated; that is the assemblable, especially assembled and/or ready-for-operation turbomachine housing element is not adapted or used for active circulation, specifically for (active) feeding and/or discharging and/or circulating of fluid into, out of or through this cavity or these cavities.

In contrast to an active temperature control where cooling or heating fluid is actively circulated through control channels, this is based in an embodiment on the approach of providing a passive thermal insulation through the use of the cavity or cavities, which is/are not actively traversed by flow, making it possible to reduce and/or retard a thermal conduction in the turbomachine housing element, especially away from the flow channel, specifically radially or orthogonally away therefrom—relative to an axial direction of the flow channel—, and, in fact, thereby making it possible to adapt a thermal expansion of the turbomachine housing element to that of the rotor blade assembly or assemblies accommodated in the flow channel thereof.

An embodiment of the present invention also provides that a single-piece or composite seal, especially an abradable liner and/or a honeycomb seal that is manufactured separately from this cavity or these cavities, that is (configured) separately from this cavity or these cavities, and is referred to accordingly in the present case as a separate seal, be attached to the turbomachine housing element between the first cavity and the flow channel and, in a further embodiment, between (a configuration) of the first cavity and of the one cavity or more of the further cavities, on the one hand, and the flow channel, on the other hand, namely by form-locking engagement, friction-locking engagement, and/or in a material-to-material bond.

In contrast to eliminating the need for a sacrificial ring due to an active temperature control where cooling or heating fluid is actively circulated through control channels, this is based in an embodiment on the approach of providing or enhancing a passive thermal insulation through the use of the seal, in fact, in addition to this cavity or these cavities, making it possible to reduce and/or retard a thermal conduction in the turbomachine housing element, especially away from the flow channel, specifically radially or orthogonally away therefrom—relative to an axial direction of the flow channel—, and especially thereby making it possible to (further) adapt a thermal expansion of the turbomachine housing element to that of the rotor blade assembly or assemblies accommodated in the flow channel thereof.

Additionally or alternatively, in an embodiment of the present invention, the first cavity and, in a further embodiment, the or more of the further cavities (in each instance) extend(s) in the axial direction of the flow channel over at least 20%, especially at least 50%, especially at least 60%, especially at least 75%, of a minimal axial length of the turbomachine housing element at the level of this (specific) cavity and/or of a minimal axial length of the separate seal.

In contrast to an active temperature control where cooling or heating fluid is actively circulated through narrow control channels, between which wide thermal bridges are formed for absorbing or dissipating heat, this is based in an embodiment on the approach of providing or enhancing a passive thermal insulation, making it possible to reduce and/or retard a thermal conduction in the turbomachine housing element, especially away from the flow channel, specifically radially or orthogonally away therefrom—relative to an axial direction of the flow channel—, and especially thereby making it possible to (further) adapt a thermal expansion of the turbomachine housing element to that of the rotor blade assembly or assemblies accommodated in the flow channel thereof.

Additionally or alternatively, in an embodiment of the present invention, the first cavity and, in a another embodiment, the one cavity or more of the further cavities is/are filled, especially in a steady-state operation, with a thermally insulating fluid whose specific thermal conductivity λ, specifically measured in [W/m·K] and/or at 0° C. and/or in accordance with DIN 4108-4, is at least 10% lower than specific thermal conductivity λ of air, in fact at least 10% lower than 0.026 W/m·K.

In contrast to an active temperature control where cooling or heating fluid is actively circulated, that, for this purpose, is inherently supposed to have a highest possible thermal conductivity, this is based in an embodiment on the approach of providing or enhancing a passive thermal insulation, making it possible to reduce and/or retard a thermal conduction in the turbomachine housing element, especially away from the flow channel, specifically radially or orthogonally away therefrom—relative to an axial direction of the flow channel—, and especially thereby making it possible to (further) adapt a thermal expansion of the turbomachine housing element to that of the rotor blade assembly or assemblies accommodated in the flow channel thereof.

In another embodiment of the present invention, the first cavity and, in a further embodiment, the one cavity or more of the further cavities is/are (each) filled with air, especially in a steady-state operation. In an embodiment, this makes it possible to realize an especially simple thermal insulation.

In an embodiment, the volumes of the first cavity and the one cavity or more of the further cavities and/or the volumes of two or more of the further cavities (each) differ by at least 1%, more specifically by at least 2%, more specifically by at least 10%, and/or at most by 200%, more specifically by at most 100%, more specifically by at most 50%.

In contrast to an active temperature control where cooling or heating fluid is actively circulated through identically constructed control channels, this is based in an embodiment on the approach of adapting a passive thermal insulation in a way that makes it possible to reduce and/or retard a thermal conduction in the turbomachine housing element, especially away from the flow channel, specifically radially or orthogonally away therefrom—relative to an axial direction of the flow channel, and especially thereby making it possible to (further) adapt a thermal expansion of the turbomachine housing element to that of the rotor blade assembly or assemblies accommodated in the flow channel thereof.

In an embodiment, the turbomachine housing element does not have any channel extending from the first cavity and/or any channel from the cavity or one or more of the further cavities to a surface of the turbomachine housing element. In other words, this cavity or these cavities may be sealed off.

In contrast to the feeding and discharging of cooling or heating fluid into and out of the control channel or control channels, respectively, it is possible to advantageously reduce the outlay for equipment and/or (dis)assembly.

In an embodiment, the turbomachine housing element has only or at most one channel extending from the first cavity and/or (in each case) only or at most one channel extending from the cavity or one or more of the further cavities to a surface of the turbomachine housing element. In an embodiment, additionally or alternatively, (each) channel extending from the first cavity and/or from the and/or more of the further cavities to a surface of the turbomachine housing element features a minimum cross section that is traversable by flow, especially a cross-sectional area in a sectional view extending orthogonally to the longitudinal channel direction, that is at most 25%, especially at most 10% of this cavity's minimum cross section that is traversable by flow, especially a cross-sectional area of this cavity in a meridional section or a plane section that contains the axial direction of the flow channel and/or a (main) machine axis of the turbomachine.

In an embodiment, such individual and/or narrow (outlet) channels make it advantageously possible for residual material remaining from the additive manufacturing process to be discharged from the cavity or cavities and, at the same time, for a passive thermal insulation to be realized or enhanced, especially in the context of little outlay for manufacturing and/or assembly.

In a further embodiment, the channel or one or more of the channels extending to a surface of the turbomachine housing element may interconnect the first and the further cavity and/or two or more of the further cavities, and/or may end at a surface of the turbomachine housing element facing away from the flow channel.

In an embodiment, residual material remaining from the additive manufacturing process may be advantageously discharged from the cavity or cavities through such joint and/or outwardly leading (outlet) channels.

In an embodiment, the turbomachine housing element is manufactured in one piece or one part and/or annularly formed. Additionally or alternatively, the first cavity and/or one or more of the further cavities is/are annularly shaped.

In an embodiment, a passive thermal insulation may be hereby enhanced, making it possible to reduce and/or retard a thermal conduction, especially away from the flow channel, specifically radially or orthogonally away therefrom—relative to an axial direction of the flow channel —, and especially thereby making it possible to (further) adapt a thermal expansion of the turbomachine housing element to that of the rotor blade assembly or assemblies accommodated in the flow channel thereof.

As explained earlier, in an embodiment, the first cavity and/or the cavity or one or more of the further cavities is/are designed, especially in terms of the size, shape, number and/or position thereof, in the turbomachine housing element for passively adapting a thermal expansion of the turbomachine housing element to that of the rotor blade assembly.

