Patent Publication Number: US-9404390-B2

Title: Device for installing and removing a component on or in a stationary gas turbine and method for installing and removing a component of a stationary gas turbine

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is the US National Stage of International Application No. PCT/EP2012/066772 filed Aug. 29, 2012, and claims the benefit thereof. The International Application claims the benefit of European Application No. EP11007152 filed Sep 2, 2011. All of the applications are incorporated by reference herein in their entirety. 
     FIELD OF INVENTION 
     The invention relates to a device for installing and removing a component on or in a stationary gas turbine and to a method therefor. 
     BACKGROUND OF INVENTION 
     Stationary gas turbines have been known for a long time from the extensive prior art. One known type of stationary gas turbine is equipped with combustors, known as tubular combustors or can-type combustors, which are evenly distributed around the circumference. Each of these tubular combustors always comprises a burner, sitting in the gas turbine housing, having a burner pipe to which a transition pipe or transition connects. The transition pipes guide the hot gas produced in the individual cylindrical burner pipes into an annular duct. To this end, the transition pipes have, on the burner side, a circular cross section which turns into a sector-shaped cross section on the outlet side. The sector-shaped cross sections of all the transition pipes generally abut against one another in the circumferential direction such that the hot gas produced in the individual tubular combustors can be guided, with little loss, into the annular duct of the gas turbine. In the annular duct, the turbine blades arranged in the turbine are arranged in stages. 
     When servicing, if one of the burners, the burner pipes or the transition pipes has to be replaced, it was the case until now that installers had to release the attachment of the relevant gas turbine component, after which this component could be removed—by hand or with the aid of a hoist—from inside the housing through the burner opening arranged in the housing. 
     Thereafter, and also during assembly of the gas turbine, functional components to be inserted can then also be moved with the aid of the hoist to the gas turbine and then into it. 
     In particular, using the hoist, components to be detached or attached on or in the lower housing half can only be transported to their intended location in an inadequate manner since the gas turbine housing partially blocks the path of the hoist or its cables or chains. 
     In order to make this work easier, U.S. Pat. No. 5,921,075 discloses a burner replacement system in which a rail is attached at a circumferential flange connection of two axially adjacent parts of the gas turbine housing, wherein a carriage of complex design can be moved along this rail in order to transport the burner to be installed. The carriage is equipped with an articulation and with a burner carrier which can be displaced in translation such that it can transport individual burners of the gas turbine to their intended location. With the aid of the known burner replacement system, the transition pipes can also be removed from inside the gas turbine or inserted inside the gas turbine. 
     A disadvantage of the known device is, however, that it is very large and requires a comparatively large maneuvering space around the gas turbine housing. This free maneuvering space is so large that its outermost radius is far greater than the outermost radius of the gas turbine housing. However, this maneuvering space is not always available. A further disadvantage of the known device is that, on account of the comparatively long and free-ending rod assembly on the carriage, and the considerable weights of the components to be replaced, such as burners and transition pipes, these can only be positioned with insufficient precision with respect to the component opening through which they are to be introduced into the gas turbine. 
     U.S. Pat. No. 6,141,862 shows a further development of the device from U.S. Pat. No. 5,921,075. In order to further support the carriage end, which previously projected freely, a second endless circumferential rail is provided in the central section of the compressor. One disadvantage, however, is the extensive configuration of this variant. In addition, it required the annular fuel distributor to be dismantled before mounting the burner removing device. 
     Furthermore, a tool for removing combustor components of a gas turbine is known from EP 2 236 939 A1. The tool comprises a telescopic unit for moving the combustor component into the gas turbine. However, the tool must be attached to each insertion opening, which is comparatively laborious. 
     In addition, a crane solution for installing and removing combustor components of a gas turbine is known from EP 2070663 A1. 
     SUMMARY OF INVENTION 
     It is therefore an object to provide a device for installing and removing a component on or in a stationary gas turbine, which device, on one hand, is comparatively compact and, on the other hand, allows exact-fit positioning of the relevant component on or in the stationary gas turbine. It is a further object to provide a method for installing and removing a component of a stationary gas turbine, which method can be carried out comparatively quickly without a particularly large installation space requirement. 
     The object directed at the device is achieved by a device according to the device features as claimed. The object directed at the method is achieved by a method as claimed. Advantageous configurations of the device and of the method are specified in the respective subclaims. Unless otherwise indicated, the features of different subclaims can be combined with one another in any manner desired. 
     It is provided according to aspects of the invention that the device for installing and removing a component on or in a stationary gas turbine comprises a rail system having a frame carriage which can be moved on and along it and on which there is arranged an insertion unit having a carrier unit for the component which can be displaced thereon along a displacement axis, wherein the rail system has two tracks, that is to say comprises two rails, wherein both rails of the rail system are configured so as to be attached to a wall section, having the insertion opening, of the gas turbine and the displacement axis extends between the two rails, transversely to—preferably perpendicularly to—a plane defined between the rails. The frame carriage, the insertion unit and the carrier unit—with or without a component temporarily attached thereto—will also be referred to hereafter as the movable unit. 
     Embodiments of the invention are thus based on the knowledge that it is disadvantageous to attach the rail system known from the prior art on the housing flange of the gas turbine. Attaching the rail system close to the insertion opening is much more useful in terms of construction. As there is, however, only limited space available at this part of the housing, the invention proposes the use of a two-track rail system which is attached to that same wall on which the insertion openings are also arranged. In this case, the rails and the components sliding or rolling thereon can be made smaller than in the case of a configuration having only one rail. In order to obtain a particularly small device overall, it is provided that the two rails can be attached to the housing of the gas turbine on either side—that is to say further inward and further outward with respect to the machine axis of the gas turbine—of the insertion opening for the relevant component. The component to be installed or removed can then be installed between the two rails, in that the carrier unit can be displaced along a displacement axis, which displacement axis is transverse, preferably perpendicular to a plane defined between the two rails. The rails are therefore only wide enough apart for the insertion opening to be completely free when the device is attached to the gas turbine. Nonetheless, the two rails are positioned right next to the insertion opening. The relevant component can thus be readily moved along the displacement axis, between the two rails into or out of the gas turbine. It has further been recognized that, by means of the two-track rail system, much greater stiffness and strength of the device overall can be achieved at the same time, since the weight of the component and also of the device itself are diverted in a distributed manner via the carrier unit, the supporting rails and the frame carriage, and then via a plurality of contact points, into the rail system, and from there further into the housing of the gas turbine. 
     Of further advantage is that, with respect to the central axis of the gas turbine, no large diameter such as in the case of the prior art is necessary for the maneuvering space of the installation device, since even the outer rail of the rail system is positioned inside the outermost diameter of the housing of the gas turbine. 
     Advantageous configurations of the invention are specified in the subclaims. 
     The rail system is formed either as an endless circular path or as an arc of a circle. It is preferable, however, for the rail system to be formed as an endless circular path such that, with the aid of this endless circular path, the frame carriage and the insertion unit and carrier unit arranged thereon can move to every one of the insertion openings arranged on the gas turbine. In the case of a rail system formed as an arc of a circle, the rail system would have to be dismantled and reassembled multiple times, each time at another circumferential position. Both configurations shorten the set-up time for preparing the installation and removal of the component on or in the stationary gas turbine. 
     According to a further advantageous configuration, the rail system comprises, for each rail, a plurality of rail holders for attaching the rail system to the gas turbine. The rail holders can be configured in a modular fashion so as to be able to attach them to the insertion openings of the burner. However, the rail system can also be attached next to the insertion openings, for example also by means of bolts. 
     According to a further advantageous configuration, the frame carriage comprises, for each rail of the rail system, at least two roller carriages which are moved synchronously on the respective rail and which preferably comprise, in each case, at least two rollers. With the aid of the total of four roller carriages and therefore altogether eight rollers, the frame carriage can be securely attached to the two-track rail system without further auxiliary means having to prevent derailing of the frame carriage, which can be moved along the circumference of the gas turbine. In a particularly preferred configuration, each roller carriage has four rollers, such that the frame carriage has 16 rollers in total, such that the frame carriage supports itself on both sides of the relevant rail at each of its four corners. In addition, the weight of the movable unit and of the component to be installed can thus be diverted into the rail system and the gas turbine housing via four corner points of the frame carriage—more precisely via the eight rollers—in a much more widely distributed manner than in the prior art. This avoids any concentrated loads, which would require larger components for the device. 
     The rollers can preferably be made to roll on those sides of the rails which in each case face the other rails. In other words, the rollers press in each case via their rolling surface against the inside of the respective rail such that, in principle, the two rails are pressed slightly apart by the rollers. The rollers are preferably configured as deflection rollers such that, in principle, the rolling surface is delimited on both sides by a wheel flange. This simultaneously produces a form fit between the respective rail and the relevant roller, such that, for each circumferential position of the frame carriage on the rail system, the frame carriage is reliably prevented from derailing from the rail system. 
     According to a further advantageous configuration, the insertion unit comprises at least two supporting rails having linear rails, along which the carrier unit can be displaced. This ensures a guided movement of the component when introducing it into the gas turbine or when removing it from the gas turbine. This prevents undesirable, accidental contact between the component and the housing, thus protecting both elements from damage. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further embodiments of the invention, further features and advantages accompanying the features are indicated in the following description of figures, in which: 
         FIG. 1  shows a perspective representation of a housing section for stationary gas turbines, 
         FIG. 2  shows a perspective, schematic representation of a housing portion of the gas turbine with the device comprising a rail system attached to the housing and a unit which can be moved along the rail system, 
         FIG. 3  shows an alternative to the rail system represented in  FIG. 2 , 
         FIG. 4  shows a side view of the device for installing and removing gas turbine components which is attached to the gas turbine housing, 
         FIG. 5, 6  show two different attachments of roller carriages on the frame carriage and 
         FIG. 7  shows an alternative configuration in which, instead of the rail system, the frame carriage is attached directly to the housing of the gas turbine. 
     
    
    
     In all the figures, identical components are provided with identical reference signs. 
     DETAILED DESCRIPTION OF INVENTION 
       FIG. 1  shows, in a perspective representation, a portion of the housing  10  of a stationary gas turbine. The housing portion comprises a lower half  12  and an upper half  14  which abut against each other, in the manner of a flange, in a parting plane  16  and whose flanges are screwed to one another. Each half has a coaxial wall section  17  and a wall section  21  arranged at a steep angle with respect thereto. Openings  18 , which all lie on an imaginary circle which is concentric with the machine axis  19 , are provided in the wall section  21  of each half  12 ,  14 . The openings  18  are burner openings or insertion openings. In the lower half  12 , a burner  20  is inserted into one of the openings  18 , whereby the opening  18  is closed. It is also possible to introduce other components of the gas turbine into the inside through the opening  18 , if lifting off the upper half  14  of the housing  10  is too laborious. The components can be burner pipes or transition pipes known from the prior art. 
     In order to permit a further simplified and also low-risk removal of the burner  20 , of the burner pipe or else of the transition pipe, and at the same time to provide a space-saving construction, it is provided to use a device  22  ( FIG. 2 ) for installing and removing these gas turbine components. Although the following exemplary embodiment merely describes the installation of a burner of the gas turbine, it is not limiting. Of course, the device  22  is also suitable for the removal of a burner. Moreover, instead of the burner, it is also possible to install or remove transition pipes with the aid of the device  22 . 
     In  FIG. 2 , for reasons of clarity, parts of the housing and of the gas turbine which are not of any further relevance for the invention are not represented. The openings  18  are positioned on the wall section  21  of the gas turbine housing  10 , which is at only a comparatively slight angle to the radial direction of the machine axis  19 . 
     The device  22  comprises a rail system  23  having two rails, an outer rail  25  and an inner rail  26 . The terms “inner” and “outer” relate to the machine axis  19  of the gas turbine. Each rail  25 ,  26  is attached to the wall section  21  via a plurality of rail holders  28 . The inner rail  26  can, in addition or as an alternative, also be attached to the coaxial wall section  17 . The device  22  further comprises a unit  35  which can be moved along the rails  25 ,  26 . This unit  35  has a frame carriage  30  and an insertion unit  36  attached to the frame carriage  30  and having a carrier unit  40  which can be displaced thereon in the longitudinal direction. The component to be installed—a burner  50  in the case of  FIG. 2 —for the tubular combustors of the gas turbine is screwed onto the carrier unit  40 . Another burner  50  is already attached in one of the openings  18 . 
       FIG. 3  shows, in contrast to  FIG. 2 , an alternative device  22 , which differs from the device  22  of  FIG. 2  substantially in that the rail system  23  extends only over an arc of a circle of the circumference of the gas turbine housing  10  and is not configured—as in  FIG. 2 —as an endless circular path. 
     As can be seen in particular from  FIG. 3 , at each corner  27  of the frame carriage  30  there is provided a roller carriage  32  having in each case two rollers. The rollers  34  are in the form of deflection rollers, that is to say formed with a wheel flange on both sides such that the rollers  34  cannot slide off to the side of the rails  25 ,  26 . The frame carriage  30  and therefore also the insertion unit  36  with the carrier unit  40  can be displaced along the rails  25 ,  26  in the circumferential direction of the gas turbine housing  10 , this being represented by the double arrow  52 . At the same time, the carrier unit  40  can be displaced along a rail system  23 , this being represented with the aid of the double arrow  54 . The travel of the frame carriage  30  and the displacement axis of the carrier unit  40  are thus transverse to one another. 
     With the aid of the devices  22  represented in  FIGS. 2 to 4 , it is possible to install and remove a component, for example a burner  50 , on or in the stationary gas turbine in a comparatively simple and exact-fitting manner. In order to install the burner  50  on the housing  10  of the gas turbine, the rail system having the rails  25 ,  26  must first be arranged on the housing  10  of the gas turbine. Next, the frame carriage  30 , having the insertion unit  36  arranged thereon and having a carrier unit  40  which can be displaced thereon along a displacement axis, is introduced into the rail system  23 . Simultaneously, a sheathed cable is attached to a hook  56  of the displaceable unit  35  and the unit  35  then hangs from the sheathed cable. The unit  35  can be moved to any position with the aid of the sheathed cable, without installers having to hold the weight of the unit  35  and of the burner. In a twelve o&#39;clock position, the burner  50  can be temporarily attached to the carrier unit  40  for the last section of the transport path. By changing the length of the sheathed cable, the burner  50  can be transported with the aid of the movable unit  35  to that opening  18  at which the burner  50  is to be attached. There, the unit  35  is then secured against further movement, which on one hand takes the load off the sheathed cable and on the other hand allows a particularly exact alignment of the burner  50  with respect to the opening  18 . Next, the carrier unit  40  is displaced along its displacement axis such that, during this time, the burner  50  enters the gas turbine through the opening  18  without any component-damaging contact. Once the final position has been reached, a flange  51  arranged on the burner  50  can be screwed to a flange  58  located around the opening  18 . The burner  50  is then detached from the carrier unit  40 , whereupon the installation of the relevant burner  50  is complete. The movable unit  35  then travels back to a loading position in which the next component to be installed can be attached to the carrier unit  40 . 
     It is of particular advantage in this context that the components to be installed can be installed at an easily accessible location in a “loading position” on the movable unit  35  and can be transported into an installation position which is less accessible by means of a type of revolver system. In particular, the openings  18  arranged in the lower housing half are to be considered as comparatively difficult to reach since, in the absence of a device  22  of this type, they can only be fitted with burners unsatisfactorily with the aid of a loading crane. A further advantage of the device  22  is that installation steps can, in part, be carried out in parallel. It is thus conceivable, for example, that a burner  50  positioned with the aid of the frame carriage  30  is first helpfully attached to its opening  18  and then the attachment to the carrier unit  40  is released. The frame carriage  30  along with the carrier unit  40  is then available to be loaded with the next burner  50  to be installed, during which time the first helpfully attached burner  50  is then attached to the housing  10  as specified while at the same time the frame carriage  30  is loaded with the next burner  50 . 
     The rail holding arrangement  28  comprises a mount  29 , a plate  31  and a seat  33 . The use of the mount  29  is of particular advantage if the rail holder  28  is to be mounted on a gas turbine to which burners are still attached on the opening  18 . In this case, the use of a mount  29  is not necessary, which means that, regardless of whether or not a burner  50  is attached to an opening  18 , the rail  25  or  26  is always at the same distance from the wall section  21 . 
     However, the rail holding arrangements  28  are preferably not attached to the flange  58  on the end face side but are either attached laterally to the flange, laterally to the wall section  21  or else to the wall section  17  itself. This means that every opening  18  can be fitted with burners  50  and is not blocked by any rail holding arrangements  28 . 
       FIGS. 5, 6  show, in cross section, two different configurations of roller carriages  32  having in each case two rollers  34  arranged thereon. They are mounted on the axles  62  by means of an applied bearing arrangement having two roller bearings  60 , wherein they are axially secured in one direction by means of a shaft shoulder and in the other direction by means of a groove nut. Both axles  62  are securely clamped in the axle holder  64  by means of a nut  65 . In order to ensure that both rollers  34  always lie against the rail, the axle holder  64  is rotatably mounted. To that end, there is provided a bearing arrangement, having a radial sliding bearing  66  and two appropriate axial sliding bearings, which is immobilized in the axial direction by means of a groove nut  67  pressed onto a lug. The bearing arrangements for the axle holder  64  on the longitudinal struts inside and outside are in this case achieved differently. An eccentric  69  ( FIG. 5 ), which allows the roller carriage  32  to be shifted in the direction of the rail, is introduced inside the longitudinal brace. At the same time, the alignment of the movable unit  35  with respect to the openings  18  can be adjusted by means of the eccentric. To that end, the upper axle portion of the eccentric  69  is inserted with a clearance fit into the bearing seat. By means of an introduced hex socket on the end face of the upper axle portion  68  of the eccentric  69  and the external threading, the eccentric can be pressed against the inner rail with a defined force and can be fixed by tensioning the components. 
     It is of course also possible to configure the frame carriage  30  without a roller carriage  32  and to attach it directly to the housing  10  of the gas turbine with the aid of an intermediate tool  60 , as shown in  FIG. 7 . 
     In all, embodiments of the invention thus relate to a device  22  for installing and removing a component, preferably a burner  50  or a transition pipe of a gas turbine, on or in a stationary gas turbine, comprising a rail system  23  having a frame carriage  30  which can be moved on and along it and on which there is arranged an insertion unit  36  having a carrier unit  40  for the component which can be displaced thereon along a displacement axis. In order to provide a particularly space-saving and particularly rigid construction, by means of which components of a gas turbine can be installed and removed comparatively simply and quickly, it is provided that the rail system  23  is formed with two tracks, and the displacement axis extends between the two rails  25 ,  26 , transversely to a plane defined between the rails  25 ,  26 . The defined plane is thus annular in shape and only slightly inclined with respect to the radial direction of the machine axis  19 .