EP3194725A1

EP3194725A1 - Rotor, axial compressor, installation method

Info

Publication number: EP3194725A1
Application number: EP15788071.7A
Authority: EP
Inventors: Viktor Hermes; Rosario Montante; Erich Muranyi
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2014-12-04
Filing date: 2015-11-03
Publication date: 2017-07-26
Anticipated expiration: 2035-11-03
Also published as: US20170268536A1; WO2016087153A1; CN107002493B; RU2017123340A; CN107002493A; DE102014224844A1; RU2678865C2; EP3194725B1; RU2017123340A3; US10830253B2

Abstract

The invention relates to a rotor (R), of a multi-staged axial compressor (ACO), which extends along an axis of rotation (X), wherein the rotor (R) has a shaft (SH), wherein the shaft (SH) has rotor blade slots (RBG), wherein rotor blades (RB) of the rotor (R) which are arranged next to one another in the circumferential direction (CD) and are each secured to the rotor blade slots (RBG) by means of a blade root (RBF) form a respective rotor blade stage (RBS), wherein at least two rotor blade stages (RBS) are provided in axial succession and an interspace slot (IG), extending in the circumferential direction, is provided in the shaft (SH) axially between the two rotor blade stages (RBS), wherein the rotor blade slots (RBG) open into the interspace slots (IG) and this arrangement is designed such that blade roots (RBF) of the rotor blades (RB) can be inserted radially into the interspace slots (IG) and can be pushed thence into the rotor blade slots (RBG). In order to improve the aerodynamics and to simplify installation, it is proposed that the rotor (R) has an interspace cover (IC) which covers the interspace slots (IG), wherein the interspace cover (IC) is designed segmented into interspace cover segments (ICS) in the circumferential direction (CD).

Description

description

Rotor, axial compressors, method for mounting The invention relates to a rotor of a multi-stage axial compressor, which extends along a rotational axis, the rotor having a shaft, said shaft having drive vane ^¬, wherein adjacently arranged in peripheral direction and at the Laufschaufelnuten each case by means of a blade root attached to the rotor blades of the rotor depending ^¬ weils form a blade stage, said axial rear reinan ^¬ the at least two blade stages are provided and which extends in the peripheral direction Zwischenraumnut is provided in the shaft axially between the two blade stages, the Laufschaufelnuten open into the Zwischenraumnuten and this arrangement is designed such that blade roots of the blades can be introduced radially into the clearance grooves and can be inserted from there into the blade grooves, wherein the rotor comprises an interspace cover which surrounds the intermediate blades raumnuten covers, wherein the space cover is formed segmented in the circumferential direction in space cover segments, wherein the space cover segments are positively secured to the shaft.

In addition, the invention also relates to an axial compressor and a method for mounting the axial compressor with the above Ro ^¬ tor. The most common attachment of blades to a massive

Shaft of an axial compressor provides that an extending in the circumferential direction groove with undercuts on the shaft is provided and the rotating blades with a corresponding also undercut trained foot at a certain circumferential position radially into this circumferential groove at a threading point in a certain scope - Position are introduced and then to the ready for the assembled shaft or for the fully assembled rotor intended circumferential end position to be moved. The feet of the blades are hereby regularly formed as Hammerkopffuß and the connection of the shaft with the blade is positively.

The Hammerkopffuß connection is already out of the

US 8,858,181 B2 known.

A less reliable connection can also take place by means of non-undercut trained blade feet on the shaft, for example by means of locking pins, which plug in the axial direction connect a shaft shoulder with a drilled in the axial direction blade foot positively. Such training is for example from the

US 2, 671, 634 known.

From DE69525014T2 it is already known to provide massive rotors of turbomachinery with circumferentially extending groove covers between the blade stages.

Axially between the two blade stages of a compressor of the above type is regularly seen before ^¬ a guide blade stage, which aligns the process of the axial compressor through the process fluid for entry into the downstream run ^¬ blade stage accordingly. The advantage of a blade which is fastened in a circumferential groove extending in the circumferential direction lies in the low production ^expenditure , since the bypass groove can be produced by a simple turning operation. The foot geometry as a hammer head, which is regularly provided for positive fastening in higher-loaded axial compressors, in conjunction with the circumferential groove in the shaft and the orientation of the blade on the rotor in such a way that only a limited contact surface between the shaft material and the Blade ^¬ foot material for transmitting forces from the blade to the shaft is available. In particular, each is an individual ^¬ blade only to the number of running blades of a stage above the circumferential small circumferential segment is available, the power to the undercut in the circumferential groove to übertra ^¬ gene. This is by means of the undercut of the foot in the geometry of the hammer head foot established that the width in the circumferential direction of the Anlageflä ^¬ surfaces of the undercut can not go beyond the width of the circumferential segment. Demensprechend acts for the transmission of forces available geometry of the circumferential groove with the Hammerkopffuß limiting the rotational speed and the diameter of the rotor at a certain mass of the blade. If the specific forces are too high, it is known that the rotor blade on the shaft is no longer to be fastened in a form-fitting manner by means of a circumferential groove, but by means of a substantially axially tangential separate fastening groove for each individual blade on the shaft. This fastening groove in the shaft for the drive show ^¬ fel may in this case be formed straight or curved with a constant radius. The Laufschaufein be pushed into these mounting grooves with a provided with undercuts blade root, wherein a direction of movement of the insertion movement is provided with at least one axial component. As a rule, the insertion direction runs obliquely to a rotation axis of the rotor at an angle which is particularly advantageous mechanically for the alignment of the blade leaf and the blade root. The fastening ^¬ grooves of such a blade attachment is not incorporated by means of a rotary process in the shaft son ^¬ countries are milled in the shaft or generated in a different way.

In a massive rotor or a substantially

integrally formed shaft that is not single

Slices is axially assembled, it is necessary for the insertion of such trained blade feet in corresponding Beigungsigungsnuten extending in the circumferential direction

Groove for radial insertion of the blade root before insertion into the mounting groove. The attachment groove opens into the circumferential groove. Instead of a circumferential groove can also a wave heel be provided. The separate for each blade mounting grooves are also designed as Tannbaumnuten. Tannbaumnuten already be ^¬ known from US 2014/0037396 Al.

The circumferential groove is characterized by the invention as a gap groove ^¬ and affects aerodynamically loss-enhancing at a flow through the Axialver. The raumnut intermediate ^¬ is also therefore covered by means of a guide blade to the flow channel out. The guide vane cover strip is fastened here as a stationary component of circumferentially extending individual segments at the radially inner tips of the guide vanes. After radially inward Leit ^{¬ the} blade vane of the vane stage is accordingly limited by the ^¬ sem circumferentially extending shroud, the rotor with the radially outer surface of this shroud at the axial transition from the blade stage in the vane stage should have substantially no radial jump. Since it is the shroud is a stationary component and a corresponding shaft seal between the shroud and the rotor is provided, corresponding movement gaps between the cover sheet and the shaft are provided, which must take into account a Axialspielbedarf and a Radialspielbedarf. These movement gaps act to increase loss when flowing through the flow channel. The solution by means of shrouds of the guide vanes to cover the circumferential grooves of the rotor between the blade stages is also complex, because the shrouds and Wel ^¬ lendichtungen are complex in the production and assembly.

The invention has set itself the task of creating a rotor of an axial compressor, which avoids the aforementioned disadvantages of the prior art.

To achieve the object of the invention is a rotor of the type defined with the additional features of characterizing part of the main claim. In addition, an axial compressor is proposed with such a rotor according to the invention. Furthermore, the invention proposes a method for manufacturing an axial compressor with a rotor according to the invention. The respective dependent claims contain advantageous developments of the invention. In addition to the demonstrated through explicit references back and exemplary explanations objects thereof of the invention are also attributable to such combinations of features disclosed, but are not explicitly or identical by these Rückbezü ^¬ ge and embodiments are disclosed useful for the professional.

A multi-stage axial compressor according to the invention is of a process fluid flows axially substantially in the compression ^¬ gradually and there is from the last stage of sealing Ver ^¬ a substantially axial outflow. The individual compression stages typically include a vane stage and a blade stage. Under the rotation axis, the invention means the axis about which the rotor of the axial compressor is rotatably formed. Unless stated otherwise, this data refers to all data relating to an axis, such as axial, radial, circumferential direction, tangential. The individual blades of a rotor blade stage of the rotor are fastened by means of a blade root to the shaft of the rotor, wherein the blade root is attributable to the rotor blade.

An advantageous development of the invention provides that each blade stage is assigned at least one in the circumferential direction extending gap groove in the shaft. This gap groove is covered according to the invention by means of a space cover radially outward. Another expedient development of the invention provides that a clearance groove two adjacent Laufschau ^¬ felstufen are assigned, so that the blade stages for mounting the blades on each blade grooves on pointing, which open for both blade stages in the same circumferential groove. In a multi-stage axial compressor with a plurality of blade stages, it is possible in this way, only in every second space between blade stages provide a clearance ^groove for mounting the run ^¬ blades. In this way, it is conceivable that intermediate spaces between blade stages in alternating sequence each have a clearance groove and have no clearance groove. The sequence might look like so: blade stage Zwischenraumnut, blade stage space without Zwischenraumnut, running show ^¬ felstufe, Zwischenraumnut, blade stage .... It is also conceivable that a hybrid of the possibility of assigning to each blade stage, a Zwischenraumnut and egg ^¬ ne Zwischenraumnut to exactly two blade stages, which are ^{¬ be} adjacent to associate, is provided. Such a mixed form is particularly useful in an odd number of blade stages.

Particularly useful in terms of a low rate of loss of flow is a cover of the space groove by means of the space covers such that a substantially continuous radial transition in the axial direction of the radially outer surface between the upstream run ^¬ blade stage and the space cover and the space cover and the downstream Schaufelstu ^¬ fe results. At this point, the advantages of the invention come to the fore, because between the space cover and the shaft main body or the shaft no movement gaps are provided, since the space cover with the shaft forms a firm connection and is mounted with-rotating. In the case of a solution with guide blade shrouds, it is scarcely possible to achieve a stumble-edge-free transition as a result of the thermally different expansion dimensions and expansion directions, in particular of stationary and rotating components. According to the invention, the shaft is formed over at least the axial Ab ^{¬ section of} two blade stages and a clearance groove as a one-piece component. Particularly preferably, the shaft is formed as a one-piece axially undivided component on the axial compressor. For a constructed from slices rotor, as is conventional in the field of gas turbines, the application of the invention is not to the same extent is beneficial because the slice-wise composition of the rotor offers ^¬ greater opportunities to cover the gap. Preferred is therefore an axially at least partially unge ^¬ divided, in particular massive one-piece shaft design over several blade stages.

A further advantageous embodiment provides that the interspace cover is arranged and designed such that the rotor blades are secured in the axial end position in the blade groove against displacement by means of the interspace cover. The space cover fulfills not only the aerodynamic function of the flow guidance but also the mechanical function of securing the rotor blade in the intended axial position on the rotor. In this case, it is conceivable for the blade feet of the rotor blade to rest against the intermediate space cover or to come into contact with the respective space cover with play. A corresponding axial clearance fit or

Press fit may be provided constructively for this purpose. While the blade feet are positively anchored to a radial disengagement on the shaft, a positive obstruction of an axial movement of the blades results through the gap cover. Particularly useful is a design of the blade feet as so-called Tannenbaumfüße, so that in comparison to a Hammerkopffuß radial successively arranged several surfaces of the Christmas tree root abut against corresponding contact surfaces of the sliding fine.

A useful development of the invention provides that the intermediate space cover segments form fit to the shaft are attached. For this purpose, each Zwischenraumabdeckungsseg ^¬ ment be equipped with a hammer foot, which can be used in a ent ^¬ speaking extending in the circumferential direction shaping the gap.

An expedient development of the invention provides that at least one gap lock ^¬ piece is provided for each Zwischenraumnut that at a particular first circumferential position of Zwischenraumnut is arranged at the Zwischenraumnut for the purpose of the radial insertion of the interim ^¬ rule space cover segments is different designed as over the remaining circumference of the shaft.

Here, it is according to the invention provided that the intermediate raumnut at least partially extending having over the circumference a first undercut which is provided with a second undercut of the gap cover segment form ^¬ conclusively ^¬ sammenwirkend formed blocking in the radial direction movement. Exactly at this point it makes sense if the space lock piece is used to cover the gap at this circumferential position and at the same time set the respective circumferential position of all Zwischenraumabde ^¬ ckungssegmente, which are arranged in this space groove. The interspace lock piece can in this case be fastened by means of a screw connection against a radial disengagement on the shaft.

At this first specific circumferential position, the gap groove advantageously has no first undercut. The axial compressor according to the invention provides that radially opposite the Zwischenraumnut and the axially adjacent to at least a moving blade stage arranged guide vane stage ^¬ the local guide vanes are formed as free-standing Leitschau ^¬ feln without a shroud.

In addition to the rotor of the axial compressor, the invention also proposes a method for mounting this rotor, which is particularly applicable for the inventive design of the rotor. sector. In a first step, a wave is thereby provided ^¬ which is fitted in a second step with the rotor blades to be inserted with the blade roots radially into the interim ^¬ schenraumnuten and then vane means of single-shifting of the blade roots of the rotor blades in the running ^¬ be attached. The axial position of the blade feet or blades on the shaft of the rotor is then secured by means of mounting the space cover segments form fit to the shaft.

In the following the invention with reference to a specific embodiment with reference to drawings closer ver ^{¬ clarified} . Show it:

Figure 1 is a schematic three-dimensional view of two adjacent blade stages and a clearance groove with clearance cover,

Figure 2 is a schematic three-dimensional view of two adjacent blade stages with intermediate therebetween gutter and a space cover in a further embodiment and

FIG. 3 shows a schematic sectional view of second adjacent blade stages of an axial compressor with a guide blade stage located therebetween in the region of the intermediate space with a clearance groove and a clearance cover. Figures 1 and 2 each show different variants of the invention with reference to two adjacent blade stages RBS in a schematic three-dimensional view. 3 shows a schematic longitudinal section through two adjacent blade stages RBS of an axial compressor ACO, which is only partially shown here. For ease of illustration, the blade stages RBS are each represented only as a single blade RB, along a circumferential direction CD actually several blades arranged side by side result in a blade stage RBS.

A shaft SH of a rotor R of an axial compressor ACO he ^¬ extends along a rotational axis X. In the jeweili ^¬ gen representations is shown in each case listed in axial sequence: a rotor blade stage RBS, a gap with egg ^¬ ner Zwischenraumnut and a gap cover IC and another Blade level RBS. In the figure 3 Zvi ^¬ rule the blade stages is reproduced radially opposite the IG Zwischenraumnut a vane stage comprising vanes GVS GV. The guide vanes GV are formed without a circumferentially extending radially inside the guide vane befindliches shroud and accordingly ^¬ freestanding. The blades RB are each connected positively in the blade grooves RBG with the shaft SH. For this purpose, blade roots RBF are introduced into the blade grooves RBG, which prevent a radial disengagement of the blades RB from the shaft SH of the rotor R. As shown in Figure 2, the Laufschaufelfü- SSE RBF are formed in the shape of a hammer head and korres ^¬ pondieren in the mold with the Laufschaufelnut in the shaft SH, so that the undercuts of the hammer head foot with which the Laufschaufelnut a positive connection ge ^¬ gen form an axial disengagement. Alternatively, the blade root can also be designed as a fir tree root or have another shape with undercuts. Between the two blade stages RBS is a gap groove IG in the shaft SH, which extends in the direction CD. The blade grooves, wherein a blade groove RBG is provided for each blade RB, Mün ^¬ all in this Zwischenraumnut IG. Here, a single Zwischenraumnut IG is provided for mounting the Laufschaufein RB for two blade stages RBS, on both sides of the gap groove IG. The rotor blades are radially inserted RB ^¬ leads with its blade root in the RBF Zwischenraumnut IG and then inserted axially substantially in the running ^¬ blade groove RBG. After all the are positioned in their final position in the rotor R and the shaft SH, the gap cover IC for Ab ^¬ cover the Zwischenraumnut IG radially outward to the Wel ^¬ le SH and the rotor R is mounted. Alternatively, individual intermediate space cover segments of the Zwischenraumabde ^¬ ckung IC can be mounted in the areas where the blades RB have already been introduced using the Zwischenraumnut IG and demensprechend secured in Endpositi ^¬ on against axial displacement by means of the gap cover segments ICS. The Zwischenraumabde ^¬ ckungssegmente ICS close the Zwischenraumnut IG of the ^¬ art, that a substantially smooth and continuous transition in the axial direction between the upstream blade stage RBS and the Zwischenraumnut IG or the intermediate compartment cover IC and the downstream moving blade stage RBS is given. The space cover segments ICS are positively attached to the shaft SH. An egg ^¬ ner certain first circumferential position of the IC Zwischenraumnut the shaft SH or Zwischenraumnut IG is designed differently for the purpose of introducing the radi- alen gap cover segments ICS than over the remaining circumference. This point is shown schematically in Figure 1, where a gap cover segment ICS has a hammerhead foot and this Hammerkopffuß with a second undercut L2 in a corresponding formation with a first

Undercut LI of the space groove IG can be introduced in the circumferential direction. At the first circumferential position, the clearance groove has no first undercut LI, so that a radial insertion of the hammerhead foot of the clearance cover segments ICS is possible. An alternative to the hammerhead feet of Figure 1 shows a reproduced in Figure 2 variant of the invention, where the Zwischenraumabde ^¬ ckungssegmente ICS have an omega shape and the second undercut L2 extends beyond the axial region of the Zwischenraumnut IG addition. The corresponding first circumferential position is not shown in FIG. 2, but for the purpose of radial insertion, the interstice cover segment must be provided. Have ICS recesses extending axially into the region of the blade stages RBS.

FIG. 3 shows one way in which a gap cover segment ICS may be formed at the first circumferential position as a gap lock piece ICL and fastened to the shaft SH. With omission of the positive connection with ^{¬ means of} the first undercut LI and the second

Undercut L2, as is preferably provided on the remaining circumferential positions of the gap groove IG, the gap lock piece ICSL is secured radially by means of a screw SR and against displacement in the circumferential direction. In this way, all gap cover segments ISC are positively fixed in the circumferential position. In principle borrowed, it is possible that all clearance Cover ^¬ ICS segments are fixed by a screw on the shaft SH SR ^¬ to additionally or exclusively, in a particular embodiment of the invention without further form closure against radial disengagement.

Claims

claims

1. rotor (R) of a multi-stage axial compressor (ACO), which extends along a rotation axis (X),

wherein the rotor (R) has a shaft (SH),

wherein the shaft (SH) Laufschaufelnuten (RBG), wherein in handling direction (CD) arranged side by side and on the Laufschaufelnuten (RBG) respectively by means of an actor ^¬ felfußes (RBF) fixed blades (RB) of the rotor (R) in each case a rotor blade stage ( RBS),

wherein axially at least two ^blade stages (RBS) are provided axially one behind the other, and axially between the two rotor blade stages (RBS) an intermediate space groove (IG) extending in the circumferential direction is provided in the shaft (SH),

wherein the blade grooves (RBG) open into the Zwischenraumnu ^¬ th (IG) and this arrangement is designed such that blade roots (RBF) of the blades (RB) can be introduced radially into the Zwischenraumnuten (IG) and from there into the blade grooves (RBG ), wherein the rotor (R) comprises a gap cover (IC) covering the gap grooves (IG),

wherein the space cover (IC) is formed in the circumferential direction (CD) segmented into space cover segments (ICS),

wherein the gap ^covering segments (ICS) are formschlüs ^¬ sig attached to the shaft (SH)

characterized in that

is the Zwischenraumnut (ICG) at least partially located points around the circumference extending a first undercut (LI) on ^¬, with a second undercut (L2) of the intermediate space cover segment (ICS) forms ^¬ form fit a direction blocking cooperatively out in the radial direction.

2. Rotor (R) according to claim 1,

wherein the gap cover (IC) covers the gap groove (IG) such that a substantially continuous The radial transition in the axial direction of the radially outer surface between the upstream ^runner blade stage (RBS) and the clearance cover (IC) and the clearance cover (IC) and the downstream rotor blade stage (RBS) results.

3. rotor (R) according to claim 1 or 2,

wherein the gap cover (IC) is arranged and formed such that the blades (RB) are secured against displacement in the axial end position in the blade groove (RGB).

4. rotor (R) according to at least one of claims 1 to 3, wherein for each Zwischenraumnut (ICG) at least one interim ^¬ c region joined pieces (ICSL) is provided, that at a certain first circumferential position of the Zwischenraumnut (IC) is disposed, on which the Space groove (ICG) for Zwe ^¬ bridge of the radial insertion of Zwischenraumabdeckungsseg ^¬ elements (ICS) is designed differently than over the remaining circumference of the shaft (SH).

The rotor (R) of claim 4, wherein the gap groove (ICG) does not have a first undercut (LI) at the determined first circumferential position.

6. rotor (R) according to at least one of claims 1 to 5, wherein the gap cover segments (ICS) and / or the interspace lock piece (ICSL) by means of at least one screw (SR) to the shaft (SH) are attached.

7. axial compressor (ACO) with a rotor (R) according to at least one of the preceding claims 1 to 5,

wherein radially with respect to the Zwischenraumnut (IG) and axially adjacent to at least one blade stage (RBS) to ^¬ ordered vanes (GV) of a Leitschaufelstufe (GVS) as free-standing vanes (GV) without shroud are ausgebil ^¬ det.

8. A method for mounting a rotor (R) of a Axialver ^{¬ poet} (ACO) according to the preceding claims 7,

with the following steps:

a) providing the shaft (SH)

b) inserting the blade roots (RBF) of the blades (RB) radially into the clearance grooves (IG)

c) Inserting the Blade Feet (RBF) of the Blades (RB) into the Blade Grooves (RBG)

d) Mounting the gap cover segments (ICS) form-fitting to the shaft (SH) to secure the blade root (RBF) axial position of the blades (RB) to the blade grooves (RBG).