U.S. patent application number 13/993422 was filed with the patent office on 2013-11-07 for tubular housing for a turbomachine.
The applicant listed for this patent is Ralf Hoffacker, Yevgen Kostenko, Gerhard Schwass, Ralph Seybold, Reiner Staubach, Adam Zimmermann. Invention is credited to Ralf Hoffacker, Yevgen Kostenko, Gerhard Schwass, Ralph Seybold, Reiner Staubach, Adam Zimmermann.
Application Number | 20130294907 13/993422 |
Document ID | / |
Family ID | 43970728 |
Filed Date | 2013-11-07 |
United States Patent
Application |
20130294907 |
Kind Code |
A1 |
Hoffacker; Ralf ; et
al. |
November 7, 2013 |
TUBULAR HOUSING FOR A TURBOMACHINE
Abstract
A tubular housing for a turbomachine is provided. The tubular
housing includes two half-tube shells which, lying against one
another in two connecting regions overlap partially in each case in
the tangential direction of the tubular housing. In order to
specify a particularly reliable and permanent connection of the two
half-tube shells which additionally develop a particularly
satisfactory sealing action, it is proposed that, in order to
interlock the half-tube shells in the tangential direction, in
relation to the tube axis of the housing, at least one eccentric
pin is provided in one or both connecting regions.
Inventors: |
Hoffacker; Ralf; (Krefeld,
DE) ; Kostenko; Yevgen; (Ratingen, DE) ;
Schwass; Gerhard; (Mulheim an der Ruhr, DE) ;
Seybold; Ralph; (Mulheim, DE) ; Staubach; Reiner;
(Wuppertal, DE) ; Zimmermann; Adam; (Mulheim a.d.
Ruhr, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hoffacker; Ralf
Kostenko; Yevgen
Schwass; Gerhard
Seybold; Ralph
Staubach; Reiner
Zimmermann; Adam |
Krefeld
Ratingen
Mulheim an der Ruhr
Mulheim
Wuppertal
Mulheim a.d. Ruhr |
|
DE
DE
DE
DE
DE
DE |
|
|
Family ID: |
43970728 |
Appl. No.: |
13/993422 |
Filed: |
October 31, 2011 |
PCT Filed: |
October 31, 2011 |
PCT NO: |
PCT/EP2011/069103 |
371 Date: |
July 16, 2013 |
Current U.S.
Class: |
415/214.1 |
Current CPC
Class: |
F05D 2240/14 20130101;
F01D 25/243 20130101; F05D 2260/36 20130101; F16B 5/025 20130101;
F16B 19/02 20130101; F16B 35/048 20130101 |
Class at
Publication: |
415/214.1 |
International
Class: |
F01D 25/24 20060101
F01D025/24 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 13, 2010 |
EP |
10194762.0 |
Claims
1-9. (canceled)
10. A tubular housing for a turbomachine, comprising: two half-tube
shells which, when in mutual abutment in two connection regions,
overlap in each case in a tangential direction of the tubular
housing; and an eccentric bolt provided in one or both connection
regions for tensioning the half-tube shells in the tangential
direction with respect to a tube axis of the housing, the eccentric
bolt including a head for turning the eccentric bolt, an eccentric
section and a shaft section, wherein the eccentric section is
arranged in the connection region in one of the two half-tube
shells, and the shaft section is arranged in the connection region
in the other of the two half-tube shells, and wherein the shaft
section or the eccentric section is mounted in a compensating
element, which is mounted such that it is displaced axially but is
fixed in rotation in or relative to one of the two half-tube
shells.
11. The housing as claimed in claim 10, wherein the two half-tube
shells are tensioned radially with respect to the tube axis of the
housing in the respective connection region by means of a screw
connection.
12. The housing as claimed in claim 11, wherein at least two screw
connections which are adjacent in a circumferential direction are
provided in each connection region.
13. The housing as claimed in claim 10, wherein a plurality of
eccentric bolts are distributed along a axial direction in the
respective connection region.
14. The housing as claimed in claim 10, wherein a lever is fastened
to the eccentric bolt the ends of which lever being in each case
articulated to a rod assembly for the synchronous adjustment of the
eccentric bolt.
15. The housing as claimed in claim 10, wherein the respective
connection region comprises a sealing region, in which is situated
a sealing means for sealing off an internal housing space with
respect to an external space.
16. The housing as claimed in claim 10, wherein the housing varies
in diameter along an axial direction of the housing.
17. A guide vane carrier for a turbomachine, comprising: a tubular
housing as claimed in claim 10.
18. An outer housing for a stationary compressor or for a
stationary turbine, comprising: an axial section which is designed
as a tubular housing as claimed in claim 1.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the US National Stage of International
Application No. PCT/EP2011/069103 filed Oct. 31, 2011 and claims
benefit thereof, the entire content of which is hereby incorporated
herein by reference. The International Application claims priority
to the European Patent Office application No. 10194762.0 EP filed
Dec. 13, 2010, the entire contents of which is hereby incorporated
herein by reference.
FIELD OF INVENTION
[0002] The invention relates to a tubular housing for a section of
the housing of a turbomachine, comprising two half-tube shells
which, when in mutual abutment in two connection regions, overlap
in each case in the tangential direction of the tubular
housing.
BACKGROUND OF INVENTION
[0003] Particularly in the context of turbomachines provided for
generating electrical energy, it is known to form the housing
thereof from two housing halves. Both housing halves are thus in
the shape of a half-tube, so that an upper housing half and a lower
housing half are present. At the circumferential ends of each
housing half, flanges extend in the radial direction of the housing
of annular cross section. A joint, which divides the housing,
exists between the flanges of the housing halves which are in
mutual abutment. On account of dividing the housing into halves,
one can also refer to a dividing plane, with the axis of the
machine lying in this plane. The diameter and axial direction of
the housing thus span the dividing plane. A multiplicity of bores,
through which in each case individual expansion screws screwed
tight on both sides of the flanges extend, are provided in the
flanges. The expansion screws press the flanges, which are in
mutual abutment in the dividing plane, tightly against each other
under high prestress in order to prevent as far as possible--or if
at all to allow to only an extremely small extent--a leakage flow
of the medium, which is conducted inside and is under high
pressure, to the outside. The above-described housing arrangement,
which is also known for example from EP 1 387 706 A1, is employed
in particular in the context of stationary gas turbines and gas
turbines provided for generating energy and also in the context of
steam turbines.
[0004] In order to seal the flanges which are in mutual abutment to
the greatest possible extent, it is necessary to provide as many
screw connections as possible at comparatively small intervals
along the axial extent of the tubular housing. However, the flanges
mean that the concentration of housing material varies along the
circumference of the housing. Locally varying rapid heating of the
housing occurs in connection with the temperatures which arise
during operation of the aforementioned turbomachines, depending on
whether there is more or less material to be heated by the hot
working medium flowing inside. This leads to different thermal
expansion at different positions on the housing, whereby the
housing becomes oval in shape. This ovalization can lead to radial
gaps of irregular size between the rotor blade tips and the wall
lying opposite these and can, in extreme cases, lead to the rotor
blade tips rubbing against the wall. The gaps of irregular size can
lead to performance losses. The rubbing endangers the integrity of
the blades on the one hand and the operation of the gas turbine on
the other. To that extent, the aim is to avoid ovalization as far
as possible. In addition, there is a delay in the flanges heating
from the inside outwards, such that the screw connections which are
arranged perpendicular to the flanges are also subject to a certain
flexural tension, which can lead to plastic deformations of the
flange screw connections which are usually already expanded as far
as the elastic limit. Following plastic deformation, the prestress
provided by the expansion screw in question for the flanges in
mutual abutment is reduced, thus negatively affecting the sealing
of the dividing joint. In addition, creep effects reduce the
lifespan of the screw connections.
[0005] As an alternative solution to the flange connections of
housing parts, an inner housing of a steam turbine which is
designed substantially as a hollow cylinder is known from laid-open
application DE 10 2006 038 021 A1. The two housing parts which form
the housing have in the region of the separation plane two
overlapping regions which are positioned opposite each other and
have wall sections which are in each case in mutual abutment and
overlap in the circumferential direction. The overlapping wall
sections each have only half the wall thickness that is otherwise
present, such that the wall thickness as seen in the
circumferential direction is always constant. The two mutually
overlapping wall sections of the housing parts are then screwed to
each other. It is thus possible to avoid the above-mentioned
drawbacks with respect to the differential concentrations of mass
at different positions on the circumference, resulting in reduced
ovalization of the housing. It is disadvantageous, however, that
the screw connections do not make it possible to generate adequate
contact pressure between the wall sections in mutual abutment. This
can result in relative movements of the wall sections pressed
against each other, whereby it is possible for the screws to
experience an additional shear load. This additional load can lead
to premature failure of the screws, endangering the safe operation
of a turbomachine equipped therewith and possibly causing leaks. To
that extent, efforts focus on solutions which reliably exclude
these shortcomings.
[0006] Notwithstanding this, the aim is to continuously raise both
the working temperature of the working medium of the turbomachine
and the pressure thereof, in order to achieve greater power and
greater efficiency of the turbomachine. This too leads to an
increased requirement with respect to the leaktightness of the
connection regions and long-term reliability of tubular
turbomachine housings which have been divided into halves.
[0007] Furthermore, screw-connecting two overlapping elements using
eccentric screws is known both from U.S. Pat. No. 1,097,185 and
from U.S. Pat. No. 3,006,443. The eccentrics of US 1,097,185 serve
to tension the two overlapping elements. U.S. Pat. No. 3,006,443
provides a countersunk arrangement of the eccentric screw in order
to reduce flow resistance.
SUMMARY OF INVENTION
[0008] The invention is based on the object of providing a tubular
housing for a turbomachine which consists of two halves of a tube
and, while avoiding the drawbacks known from the prior art, is
additionally designed so as to be especially reliable, long-lived
and extremely leaktight.
[0009] The object is achieved by a tubular housing according to the
features of the claims Advantageous configurations are respectively
the subject of subclaims.
[0010] A housing according to the invention is distinguished by the
fact that at least one eccentric bolt is provided in one or both
connection regions for tensioning the half-tube shells which
partially overlap each other in the tangential direction with
respect to the tube axis of the housing.
[0011] The invention has recognized that the screw connections,
known from the prior art, of the wall sections which overlap one
another in the tangential direction can transmit transverse forces
only by means of friction. In order to remedy this and so as to be
able to take up larger transverse forces, the invention combines,
in a previously unknown manner, two functional and operational
principles for the separable connection of divided housings. The
invention proposes transmitting the transverse forces which arise
in the tangential direction according to the principle of bearing
surfaces within the hole. A bolt seated without play in
correspondingly dimensioned bores is provided for this purpose,
which bores are in each case arranged in an overlap section of the
corresponding half-tube shell. At the same time, a relative
displacement of the two half-tube shells should be possible in
order to be able to better adjust the centricity of the housing and
tension the two half-tube shells with respect to each other in the
tangential direction. To that end, a section of the bolt is
designed as an eccentric, such that the bolt which is then formed
as an eccentric bolt allows for the two half-tube shells to be
tensioned or displaced with respect to each other during assembly
following the lever principle.
[0012] The transverse forces are de facto taken up and/or
transmitted with the aid of a plurality of eccentric bolts. To this
end, a plurality of eccentric bolts are preferably provided
distributed in the axial direction in the connection region, by
means of which bolts the two half-tube shells of the housing can be
moved with respect to each other and thereby tensioned in the
circumferential direction during assembly. The two half-tube shells
are thus connected to one another without play as seen in the
circumferential direction with the aid of the eccentric bolts.
[0013] During operation, the eccentric bolts are loaded as shear
bolts, without also being subjected to a tensile load. It is
thereby possible for these to take up larger forces, as a result of
which the housing according to the invention can in particular take
up and house further increased pressures inside the housing without
unusually great or impermissibly high leakage rates arising through
the partial joint present in the connection region. The use of the
eccentric bolts capable of higher loading thus also leads to safe
operation of a turbomachine equipped with a housing according to
the invention.
[0014] The eccentric bolt has a head for turning the eccentric
bolt, an eccentric section and a shaft section, wherein the
eccentric section is arranged in the connection region in one of
the two half-tube shells and the shaft section is arranged in the
connection region in the other of the two half-tube shells. The
eccentric bolt thus extends transversely to the two partially
mutually overlapping half-tube shells and is oriented substantially
radially with respect to the tube axis of the housing.
[0015] The shaft section or the eccentric section is in addition
mounted in a compensating element, which is mounted such that it
can be displaced axially but is fixed in rotation in or relative to
one of the two half-tube shells. This makes it possible, when
adjusting the eccentric bolt, to prevent a relative movement of the
two half-tube shells in the axial direction and obtain only a
relative movement in the tangential direction, since the
compensating element can compensate for the axial relative
displacement which also usually takes place when the eccentric bolt
is turned. To this end, the compensating element must be mounted
such that it can be displaced in the axial direction but is without
play in the tangential direction with respect to the half-tube
shell in which it is held. As a consequence, the two half-tube
shells then perform only a tangential relative displacement, making
it possible for the housing according to the invention to be
rigidly attached at its axial ends to further components.
[0016] In one advantageous embodiment, the two half-tube shells are
tensioned--that is to say pressed against each other
areally--radially with respect to the tube axis of the housing in
the respective connection region by means of at least one screw
connection. In combination with the eccentric bolt connection of
sheet-like components, i.e. the half-tube shells, the additional
use of the screw connections leads to a further improved
connection, since the overlap sections can also take up friction
forces at their contact surfaces which extend in the tangential
direction. In addition, this ensures close areal contact between
the two overlap sections. This prevents the presence of an air gap
between the overlap sections which would lead to different thermal
behavior of the two overlap sections and thus to different
mechanical loads. Consequently, the screw connections ensure a
particularly good transfer of heat between the two overlap
sections. In addition, the screw connection stiffens the connection
region. The use of the eccentric bolts also reliably protects the
screw connections from shear forces. This ensures a screw
connection between the housing halves which is reliable in the long
term.
[0017] Particular preference is given to that embodiment in which
at least two screw connections which are adjacent in the
circumferential direction are provided in each connection region.
As a result, although it is necessary to have overlap sections
which are relatively long in the tangential direction, this
configuration increases, on the one hand, the contact surface which
is relevant for friction forces and lengthens, on the other hand,
the leakage path for the medium conducted inside the housing. In
addition, the contact pressure in the contact surface of the
half-tube shells can be increased.
[0018] According to a further advantageous embodiment, a plurality
of eccentric bolts are distributed along the axial direction in the
respective connection region, wherein the eccentric bolts are in
each case articulated, via a lever fastened thereto, to at least
one rod assembly for the synchronous adjustment of the eccentric
bolts. The only requirement for this is that the central axes of
the eccentric bolts be parallel and the position or arrangement
thereof permit the use of the rod assembly. The limited turn angle
necessary for generating the prestress also means that the
eccentric bolts can easily be coupled to each other using
individual levers articulated to a common rod assembly. Actuating
the rod assembly adjusts the eccentric bolts synchronously. This
leads on one hand to an even and distributed input of force for
tensioning the two half-tube shells in the tangential direction. On
the other hand, assembly is then very quick. Unwanted distortion of
one of the two half-tube shells by successive tightening of the
eccentric bolts is hereby also precluded. In the event that the
drive of the rod assembly is also self-locking, this configuration
secures the eccentric bolts against unintentional independent
loosening.
[0019] A further advantage results from the use of seals in the
partial joint surfaces. The respective connection region therefore
comprises a sealing region, in which is situated a sealing means
for sealing off the internal housing space with respect to the
external space. The sealing means can then carry out their function
optimally, as the relative movement forced by eccentric bolts
during assembly can be used to accurately predict the
simultaneously accompanying deformation of the sealing means. This
allows the sealing means to be very well matched to the embodiment,
which leads to very high leaktightness.
[0020] That the housing is tubular does not necessarily mean that
it is cylindrical. Rather, tubular means that the cross section is
substantially circular. Accordingly, the housing can vary also in
diameter along its axial direction, as necessary. It can thus also
be designed conically in the axial section according to the
invention. It is also possible for the housing to be designed as a
guide vane carrier of a turbomachine, which guide vane carrier has
on its inward facing lateral surface means for attaching guide
vanes arranged in one or more rings. Of course, an outer housing of
a stationary compressor or of a stationary turbine--for example a
steam turbine or a gas turbine1'can also comprise at least one
axial section designed as a tubular housing in the sense of the
previously described configurations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Further advantages, features and properties of the invention
will be explained in more detail with reference to a preferred
exemplary embodiment in the following drawing. Expedient
configurations result from advantageous combinations of features.
In the drawing:
[0022] FIG. 1 shows a part of the cross section of a tubular
housing according to a first configuration.
[0023] FIG. 2 shows an eccentric bolt in a side view.
[0024] FIG. 3 shows a side view of a housing according to an
alternative configuration.
[0025] FIG. 4 shows the detail from the cross section of the
housing according to FIG. 1 with an alternative overlap.
DETAILED DESCRIPTION OF INVENTION
[0026] A detail of a tubular housing 10 for a turbomachine is shown
in a cross sectional representation in FIG. 1. The housing 10
comprises two half-tube shells 12, 13 which each extend over an arc
length of somewhat more than 180.degree.. Both half-tube shells 12,
13 here have a wall thickness d over a large portion of their arc
length, this wall thickness being constant along this extent.
Overlap sections 18, 19 of the half-tube shells 12, 13 respectively
adjoin the latter at each circumferential end, the wall thickness
of these overlap sections being just half the wall thickness d. For
reasons of strength, however, the wall thicknesses of the overlap
sections 18, 19 can also be slightly greater than half the wall
thickness d. Both overlap sections 18, 19 end respectively at the
circumferential end points 15. The two half-tube shells 12, 13 thus
overlap in a connection region 14, with the overlap sections 18, 19
being in mutual areal abutment in a contact region 16. In a
conventional manner, the tubular housing 10 here comprises two
connection regions 14, which are situated at mutually opposite
positions of the circumference of the housing 10.
[0027] The two half-tube shells 12, 13 are connected to each other
in the connection region 14 with the aid of at least one eccentric
bolt 20. The eccentric bolt 20 is shown in a side view in FIG. 2
and comprises, in succession, an eccentric head 22 to which are
attached, in succession, an eccentric section 24, a shaft section
26 and a threaded section 28. The shaft section 26 has in this case
a central axis 30 which coincides with the central axis of the
eccentric head 22. The central axis 32 of the eccentric section 24
is, in a known manner, offset by a distance e from the central axis
30 of the shaft section 26.
[0028] In the exemplary embodiment shown, the eccentric head 22 is
designed as an external hexagon. The eccentric head 22 can of
course also be designed for other forms of drive, such as an
internal hexagon or radial bores for accommodating a rotary
rod.
[0029] A bore is provided in each of the two overlap sections 18,
19. The diameter of the bore 34 located in the overlap section 19
corresponds to that of the shaft section 26 of the eccentric bolt
20. Similarly, the diameter of the bore 36 located in the overlap
section 18 is the same as that of the eccentric section 24 of the
eccentric bolt 20. As can be seen in FIG. 1, the eccentric bolt 20
is inserted with a snug fit from the outside into the corresponding
bores 34, 36 of the overlap sections 18, 19, such that the threaded
section 28 projects into the inside of the housing 10. A
self-locking nut 38 is screwed onto the threaded section 28,
whereby the eccentric bolt is secured against loss. Turning the
eccentric bolt 20 about its central axis 30 produces a force on
both half-tube shells 12, 13 which leads to the two respective
half-tube shells 12, 13 moving relative to each other.
[0030] By so doing, the two half-tube shells 12, 13 can be
tensioned against each other in the circumferential direction U.
This is important in particular if a substantially greater pressure
is present inside the housing 10 compared to the outside, or if no
separate sealing means is provided for sealing the joint. At the
same time, the two overlap sections 18, 19 of the half-tube shells
12, 13 are areally pressed against each other in the contact region
16 by two screw connections 40, which are shown only schematically.
As the screw connections 40 are installed from outside, they are
screwed into the overlap section 19 of the half-tube shell 13.
[0031] Instead of the overlap shown in FIG. 1, it is also possible
to use a double-section variant of the connection region 14, as
represented schematically in FIG. 4. This has the advantage that
the contact surface in the connection region is further enlarged
compared to the embodiment shown in FIG. 1. This lengthens the path
of any leakage arising through the joint and increases the size of
the sealing area.
[0032] Axially securing the eccentric bolt 20 need not necessarily
be carried out from the inside by means of a self-locking nut 38.
Instead, a securing measure against loss can also be provided from
the outside, which provides simpler installation of the securing
measure. For example, a frame or a plate can block the axial
displacement path of the eccentric bolt 20 and thus secure it.
[0033] An alternative and preferred configuration of the embodiment
represented in FIG. 1 is shown in FIG. 3 in a side view of the
connection region 14, where features which are identical to FIG. 1
are given identical reference numbers. The configuration of FIG. 3
differs from the configuration of FIG. 1 in that a recess 44 of
rectangular contour is provided for each eccentric bolt 20 in the
overlap section 18. The recess 44 passes right through the overlap
section 18 and is represented only in FIG. 3. A compensating
element 46 which can be displaced only in the axial direction is at
least partially introduced into each recess 44 in the form of what
is termed a sliding block. The compensating element 46 moreover has
a bore in which the eccentric section 24 of the eccentric bolt 20
is mounted without play. The diameter of the bore of the
compensating element 46 thus corresponds exactly to the diameter of
the eccentric section 24 of the eccentric bolt 20. As with the
configuration of FIG. 1, the shaft section 26 of the eccentric bolt
20 is seated without play in the bore 34 of the overlap section 19.
The contour of the compensating element 46 corresponds
substantially to that of the recess 44, as a result of which the
compensating element 46 is held fixed in rotation in the recess 44.
The axial extent of the compensating element 46 is smaller than
that of the recess 44, as a result of which the compensating
element 46 is mounted in the recess 44 in an axially displaceable
manner. However, as seen in the tangential direction T, the extent
of the recess 44 and that of the compensating element 46 are
identical, in order to ensure that the compensating element 46 is
seated without play in the recess 44, such that the eccentric bolt
20 is subjected to the shear loading.
[0034] As, conventionally, both half-tube shells 12, 13 of the
housing 10 are very limited in their axial movement, it is also
possible with the aid of the compensating element 46 to use the
eccentric bolt or bolts 20 to tangentially tension the two
half-tube shells 12, 13. This is because the axial displacement of
the two half-tube shells 12, 13 relative to each other, which
otherwise accompanies turning of the eccentric bolt 20, can be
compensated for by the compensating element 46 which can be
displaced axially but is fixed in rotation.
[0035] In an alternative configuration, which is not shown and has
a sliding block, the recess 44 can also be arranged as a purely
superficial pocket on the outward facing surface 42 (see FIG. 1) of
the overlap section 18. In this case, the recess 44 has a depth
which is smaller than half the wall thickness d. The bore 36
situated in the overlap section 18 of the half-tube shell 12 then
has a diameter greater than the diameter of the eccentric section
24 of the eccentric bolt 20, whereby the latter is seated with play
in the overlap section 18 in order not to restrict the
displaceability of the sliding block.
[0036] The arrangement of the recess 44 and the compensating
element 46 is of course also possible in the overlap section
19.
[0037] According to the embodiment represented in FIG. 3, the
connection region 14 has an axial extent in which a multiplicity of
eccentric bolts 20 and also a further multiplicity of pretensioned
screw connections 40 are distributed along the axial direction A in
a grid pattern, whereby an axial connection region can be realized.
In order to mitigate warping in the individual half-tube shells 12,
13 when tensioning using the eccentric bolts 20, it is provided
that the respective eccentric bolts 20 be turned synchronously. To
that end, a lever 48 is in each case rigidly fastened to each
eccentric bolt 20, the ends of which lever being in each case
articulated to a rod assembly 50. The two rod assemblies 50 shown
in FIG. 3 can be displaced in opposite axial directions by
hydraulically actuated pistons 52, with the result that, via the
levers 48 articulated thereto, all the eccentric bolts 20 coupled
thereto can be swiveled through the same angle synchronously during
installation. FIG. 3 shows two positions of the levers 48 by means
of solid and dashed lines respectively.
* * * * *