Abstract:
The disclosure pertains to a mounting arrangement for installing and removing a turbine component. The mounting arrangement has a base cage, a main cage, and an inner structure. The base cage includes an interface for connection to a casing of the turbine, and an interface for connection to the main cage. The main cage includes an inner structure interface for movable connection to the inner structure. The inner structure is arranged at least partly inside the main cage and the inner structure interface is configured to allow a movement of the inner structure along a defined trajectory in the main cage. The inner structure includes a first face of a component interface for holding the turbine component. The disclosure further refers to a method for mounting and removing a turbine component.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to European application 14169780.5 filed May 26, 2014, the contents of which are hereby incorporated in its entirety. 
       TECHNICAL FIELD 
       [0002]    The present invention relates to a replacing system for large parts or components of a turbine. It is applied for removing or mounting turbine components to inspect or repair these. Further, it relates to a method for removing or mounting turbine components. 
       BACKGROUND 
       [0003]    Turbine part or components need to be removed for inspection, repairment or replacement of the parts or components. Such components can for example be burners of a gas turbine for thermal power generation. Burners are typically arranged radially at equal intervals at the middle part of the main body of the gas turbine and are inserted and assembled via flanges thereto. Conventionally, such parts are replaced manually by constructing simple scaffolds after removing pipes and other obstacles around the part and by manipulating an overhead traveling crane to sling the part by workers who get on the scaffolds. 
         [0004]    Parts or components such as burners can be far too heavy to be handled by workers without the use of cranes or other lifting tools. Such a removal and handling is time consuming and it is difficult to maintain an adequate position of the burner during the works in the narrow inner space of the turbine and on the unstable outside scaffolds. 
         [0005]    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 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 turbine. 
       SUMMARY 
       [0006]    The object of the present disclosure is to provide a mounting arrangement for installing and removing a component on or in a turbine, which mounting arrangement, on one hand, is compact and, on the other hand, allows exact-fit positioning of the relevant component on or in the turbine. It is a further object of the disclosure to provide a method for mounting and removing a part or component of a turbine, which method can be carried out quickly without a particularly large installation space requirement. 
         [0007]    According to a first embodiment a mounting arrangement for a turbine component comprises a base cage, a main cage and an inner structure. The base cage comprises a first face of a casing interface for connection of the base cage to a casing of the turbine, and first face of a main cage interface for connection to the main cage. The main cage comprises a second face of the main cage interface for connection to the base cage, and a first face of an inner structure interface for movable connection of an inner structure to the main cage. The inner structure is arranged at least partly inside the main cage and has a second face of the inner structure interface for moveable connection to the main cage. The inner structure interface is configured for moving the inner structure along a defined trajectory in the main cage. Further, the inner structure comprises a first face of a component interface for holding the turbine component. 
         [0008]    The first face of the casing interface for connection of the base cage to the casing of the turbine can be a flange for ridged connection of the base cage to the casing. The first and second face of the main cage interface and of the can also be flanges for a ridged connection of the main cage to the base cage. The interfaces can also comprise other connection types like for example clamps, plug connection, bar or framework connections or toothed connections. Any other type of ridged connection is also possible. Also a connection using a strong magnet for fixation of the arrangement to the casing or for fixation of components of the arrangement to each other is conceivable. 
         [0009]    The main cage and base cage can for example have a cylindrical structure with a tube like outer wall and hollow inside. The cages can also have a framework structure or be constructed based on a cantilever arrangement. 
         [0010]    A component can for example be a combustor, burner of transition piece of a gas turbine. It can be also be an internal valve of a turbine or any part or assembly of part, which typically is too heavy for manual handling. 
         [0011]    The trajectory along which the inner structure is moved relative to the main cage can for example be a straight line; it can also be a curved line to move the turbine component around obstacles when inserting it into the casing or removing it from the casing. 
         [0012]    According to one embodiment the mounting arrangement comprises a plurality of base cages. Each base cage has one first face of the casing interface adapted for connection to different contours of different sections of the turbine casing. 
         [0013]    In a further embodiment the inner structure of the mounting arrangement comprises a sledge. The sledge can be moved relative to the main cage and base cage. 
         [0014]    According to yet another embodiment of the mounting arrangement the inner structure interface comprises a rail roller system which guides the inner structure, in particular the sledge, inside the main cage. Preferably the rail roller system has three rail roller pairs. One rail roller pair is in vertically top position of the main cage and two rail roller pairs are in a lower half of the cage spaced apart from a vertical bottom position. The lower rails can be inclined towards the vertical top position. Alternatively the a rail roller system has a rail roller pair in a vertical bottom position of the main cage and two rail roller pairs in an upper half of the main cage spaced apart from a vertical top position. The upper rails can be inclined towards the vertical bottom position. 
         [0015]    The inner structure can for example be a y-shaped sledge with a single leg towards the top and two legs angled apart towards the bottom. 
         [0016]    The rail roller pairs can for example be arranged along a rail extending in an axial direction of the inner structure and rollers pressed against the rail at two or more axial spaced apart locations. 
         [0017]    In yet another embodiment of the mounting arrangement the rail roller system comprises two planes spaced apart along a longitudinal axis of the inner structure. In each plane three roller rail pairs in each plane. In such a mounting arrangement the longitudinal axis of the inner structure can be adjustable relative to a longitudinal axis of the main cage by adjusting the position of each roller relative to the inner structure in a direction of main load transferred via the respective roller for rollers connected to the inner structure. Alternatively or in combination the longitudinal axis of the inner structure can be adjustable relative to a longitudinal axis of the main cage can be adjusted by adjusting the position of each roller relative to the main cage in a direction of main load transferred via the respective roller for rollers connected to the main cage. Connected in this context means for example that the roller is mounted to the inner structure respectively to the main cage with a bearing. An adjustment of the roller relative to the inner structure respectively to the main cage can for example be realized by a countered screw fixing a distance of the bearing to the respective structure. 
         [0018]    The forth interface for connection of the turbine component to the inner structure of the mounting arrangement can comprise two planes spaced apart in axial direction of the inner structure. 
         [0019]    To reduce the time needed for installing and/or removing the gas turbine part the second interface comprises at least two toggle clamps for quick locking of the interface, i.e. quick connection of the main cage to the base cage. 
         [0020]    According to another, embodiment of the mounting arrangement the main cage comprises a fix point, and the inner structure comprises a pivot support. A shifting system for moving the inner structure relative to the main cage is arranged between the inner structure and main cage and connected to the fix point and the pivot support. 
         [0021]    According to a further embodiment the mounting arrangement comprises a shifting system with screw jack system form moving the inner structure relative to the main cage. 
         [0022]    According to yet another embodiment of the mounting arrangement the shifting system comprises at least one of a manual handle, an electro motor, or pneumatic motor to drive the shifting system. 
         [0023]    Besides the mounting arrangement a method for mounting, respectively a method for removing a turbine component from a turbine is an object of the disclosure. 
         [0024]    The method for mounting, respectively removing a turbine component from a turbine comprises the step of providing a mounting arrangement for a turbine component. Such a mounting arrangement has a base cage, a main cage and an inner structure. The base cage comprises a first face of a casing interface for connection of the base cage to a casing of the turbine, and first face of a main cage interface for connection to the main cage. The main cage comprises a second face of the main cage interface for connection to the base cage, and a first face of an inner structure interface for movable connection of the inner structure to the main cage. The inner structure is arranged at least partly inside the main cage and has a second face of the inner structure interface for moveable connection to the main cage. The inner structure interface is configured for moving the inner structure along a defined trajectory in the main cage. Further, the inner structure comprises a first face of a component interface for holding the turbine component. 
         [0025]    Depending on the connection of the turbine component to turbine the method further comprises the step of disconnecting turbine component from the turbine, respectively connecting the turbine component to the turbine. If the turbine component is connected by a form fit to the turbine no particular steps have to be carried out. If the component is for example bolted the bolts have to be removed, respectively bolted. 
         [0026]    The Method for mounting further comprises the steps of connecting the first face of the casing interface of the base to the casing of the turbine, connecting the second face of the main cage interface of the main cage to the first face of the main cage interface of the base cage. The main cage is holding the inner structure and the inner structure can be moved inside the main cage such that the component interface of the inner structure can be connected to the turbine component. In subsequent steps the turbine component is connected to the inner structure at the component interface, the turbine component is pulled out of the casing by moving the inner structure along a trajectory in the main cage, and finally the main cage holding the inner structure and turbine component is detached from the casing. For detaching the main cage can be detached from the base case by opening the main cage interface or the whole mounting arrangement can be detached including the base cage by opening the casing interface. 
         [0027]    A further embodiment of the method comprises a step of aligning a longitudinal axis of the inner structure with a longitudinal axis of the turbine component before connecting the turbine component to the inner structure at the component interface. 
         [0028]    Besides providing a mounting arrangement the method for mounting further comprises the steps of connecting the first face of the casing interface of the base cage to the casing of the turbine, connecting the turbine component to the inner structure at the component interface, and at least partly pulling the turbine component in the main cage by moving the inner structure along a trajectory in the main cage. Thus an assembly holding the turbine component is obtained which can be easily handled and moved to the turbine and in particular to the vicinity of the base cage. In subsequent steps the second face of the main cage interface which is holding the inner structure and the turbine component is connected to the first face of the main cage interface on the base cage, and the turbine component is pushed into the casing by moving the inner structure along a trajectory out of the main cage towards the casing. The turbine component can be fixed in its installed position. Finally, the main cage which is holding the inner structure is detached from the casing. 
         [0029]    Before connecting the turbine component to the inner structure it can be disconnected or partly disconnected from the turbine itself. Depending on the turbine component design and accessibility the disconnection can be done after the turbine component is attached to the inner structure. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]    The disclosure, its nature as well as its advantages, shall be described in more detail below with the aid of the accompanying schematic drawings. Referring to the drawings: 
           [0031]      FIG. 1  shows a perspective view of an exemplary mounting arrangement; 
           [0032]      FIG. 2   a ,  2   b ,  2   c  different variants of base cages from  FIG. 1 ; 
           [0033]      FIG. 3  shows cut out of the main cage and inner structure with a shifting mechanism; 
           [0034]      FIG. 4  shows the inner structure of  FIG. 1  with a turbine component connected to it; 
           [0035]      FIG. 5  shows an example of an inner structure interface with a rail and adjustable roller; 
           [0036]      FIG. 6   a ,  6   b ,  6   c ,  6   d  shows examples of the alignment of the inner structure; 
           [0037]      FIG. 7   a ,  7   b  shows the mounting of a base cage and main cage on a casing for removal of combustor. 
       
    
    
     DETAILED DESCRIPTION 
       [0038]    An exemplary embodiment of the mounting arrangement  4  is shown in  FIG. 1 . The base cage  1  is used as an adaptor to connect the main cage  2  towards a casing of a turbine (direction towards casing  22 ). This part is configured to support the complete mounting arrangement  4  with main cage  2 , inner structure  3  and a combustor during mounting or removal of a combustor. The base cage  1  has a cylindrical body with first face of a casing interface  5   a, b, c  on one end of the cylindrical body and a main cage interface  6   i  at the other end of the cylindrical body. The casing interface  5   a, b, c  is configured as a flange, which is adapted to the casing section to which it is to be connected. The first face of the main cage interface  6   i  is a circular flange. 
         [0039]    In the example the core of the tool consists of a main cage  2  with an inner structure  3 . The main cage  2  has a cylindrical body and  2  is a support structure for holding and moving the inner structure  3 . The inner structure  3  is movably connected to the main cage  2  via an inner structure interface. The inner structure interface consists of a first face of inner structure interface  17   i  which in this case consists of three rails which are integrated into the inner structure  3 , and a second face of inner structure interface  17   ii  which in this example consists of six rollers attached to the main cage  2 . 
         [0040]    The main cage  2  comprises a second face of main cage interface  6   ii  for connection to the base cage  1 . The second face of the main cage interface  6   ii  is a circular flange adopted for connection to the flange of the first face of the main cage interface  6   i  with a bolt hole pattern to secure and connect the main cage  2  in a defined vertical orientation (direction of gravity). In this position one rail of the a first face of inner structure interface  17   i  is on a vertical top position inside the main cage  2  while the other two rails are in the lower half of the main cage  2 . 
         [0041]    The  FIGS. 2   a ,  2   b , and  2   c  show different variants of base cage  1 . The first face of casing interface  5   a,    5   b,    5   c  is in each case adopted for connection to different parts of the casing. The bolt hole pattern of the flange from first face of main cage interface  6   i  is identical and orientated in the same way for all base cages  1   a,    1   b,    1   c  when attached and connected to a casing via the first face of casing interface  5   a,    5   b,  and  5   c.  As a result the main cage  2  can be connected to any of the base cases  1   a,    1   b,    1   c  and will in all cases have the same orientation. In particular the inner structure  3  can be arranged vertical (parallel to a line of gravity), i.e. a top of the inner structure  3  is always arranged on top. 
         [0042]      FIG. 3  shows a cut out of the main cage  2  and inner structure  3  with a shifting system  7  for moving the inner structure  3  relative to the main cage  2 . For moving the inner structure  3  the shifting system  7  is connected to the main cage ( 2 ) via a pivot support  8  and connected to the inner structure  3  via a fix point  9 . In in this example the fix point  9  is configured as spherical joint. 
         [0043]    The shifting system  7  pushes or pulls the inner structure  3  along the rails of the first face of inner structure interface  17   i.  In this example the shifting system  7  is configured as a screw jack system. 
         [0044]    View X of  FIG. 3  shows a detail of the shifting system  7 . In this detail one can see connect hands  16  of the shifting system  7  which allow the connection of a manually operated tool or automatic tool to drive the shifting system  7 . 
         [0045]      FIG. 4  shows the inner structure  3  of  FIG. 1 , respectively of  FIG. 3  with a turbine component  12  connected to it. For illustrative purposes the main cage is not shown in this perspective view of the mounting arrangement as it would block the view on the inner structure  3  and component  12 . The component interface  18   a,    18   b,  i.e. in this example the connection to a combustor can be divided into two areas/planes (plane of component interface  18   a,  and of component interface  18   b ). At the first connection plane a cylindrical flange is used as component interface  18   a.  The flange is connected via an intermediate ring  10  which can be installed on the turbine component  12  (in this case combustor). In this example a  4   x  bolt connection is shown. In the second plane, i.e. the plane of component interface  18   b,  another type of connection is shown. This connection consists of three brackets  11  which can be preassembled on the combustor. For connection to the inner structure  3  cut outs are provided on ears of the inner structure  3 . Two rotatable bolts  13  can be rotated towards centerline of the bracket  11 , and tightly connected with nuts  14  to available pockets  15  on the inner structure  3  (in this example the ears with pockets  15  form the first face of the component interface  18   b ). The bracket connection of the component interface  18   b  is shown with open bolts in detail A and with closed bolts in detail B. 
         [0046]    For alignment of the inner structure  3  with the turbine component  12  for connection of the turbine component  12  to the inner structure  3  the position of the six rollers of the second face of inner structure interface  17   ii  can be adjusted relative to the inner structure  3 . This adjustment can be carried out from outside of the main cage  2 . It also allows an alignment of the turbine component  12  connected to the inner structure  3  with the casing  21  for moving the turbine component at least partly into the casing  21  and mounting it to the casing  21 . 
         [0047]    The three rollers of each plane are adjusted as a group. One roller is vertical on top of the section and two rollers are arranged in the lower half of the cross section with opposite angular positions. For adjusting the position of the inner structure  3  relative to the main cage  2  the rollers of are settable relative to the inner structure  3  in a direction of main load transmitted via the respective roller. 
         [0048]    A detail of a settable roller attached to the main cage  2  is shown in  FIG. 5 . For adjustment of the roller, i.e. the second face of inner structure interface  17   ii,  the roller is mounted in a bearing block  25  which is movably housed in a recess  26  in the main cage  2 . The bearing block  25  is retained in the recess  26  by spring loaded bolts  23  which pull the bearing block  25  in the direction of main load transferred via the respective roller towards the wall of the main cage  2 . The bearing block  25  is stopped and kept in its position by an adjustment screw  24  which is screwed through the wall of the main cage  2  and reaches into the recess. By turning the adjustment screw  24  the bearing block can be moved in a direction of the main load transferred via the respective roller thus the distance between the inner wall surface of main cage  2  and the inner structure  3  can be adjusted. 
         [0049]    Using three adjustable rollers in two plains the inner structure can be aligned as shown in the examples of  FIGS. 6   a ,  6   b ,  6   c , and  6   d    
         [0050]    In the example of  FIG. 6   a  the inner structure  3  is adjusted in an upwards direction relative to the main cage  2 . For upwards adjustment the top bearing block is pulled into the recess (in direction al) and the lower bearing blocks are pushed out of the bearing block (direction a 2  and a 3 ). 
         [0051]    In the example of  FIG. 6   b  the inner structure  3  is adjusted in a downwards direction relative to the main cage  2 . For downwards adjustment the top bearing block is pushed out of the recess (in direction b 1 ) and the lower bearing blocks are pulled into the bearing block (direction b 2  and b 3 ). 
         [0052]    In the example of  FIG. 6   c  the inner structure  3  is adjusted towards the left side relative to the main cage  2 . For leftwards adjustment the top bearing block is pulled into the recess (in direction c 1 ) and the lower bearing block left of a vertical center line of the inner structure  3  is pulled into the recess of the bearing block (direction c 2 ) while the lower bearing block right of a vertical center line of the inner structure  3  is pushed out of the recess of the bearing block (direction c 3 ). 
         [0053]    In the example of  FIG. 6   d  the inner structure  3  is adjusted towards the right side relative to the main cage  2 . For rightwards adjustment the top bearing block is pulled into the recess (in direction d 1 ) and the lower bearing block left of a vertical center line of the inner structure  3  is pushed out of the recess of the bearing block (direction d 2 ) while the lower bearing block left of a vertical center line of the inner structure  3  is pulled into the recess of the bearing block (direction d 3 ). 
         [0054]      FIG. 7   a ,  7   b  schematically show the main stages of the mounting of a base cage  1  and main cage  2  on a casing  21  for removal of a combustor  12 . In  FIG. 7   a  the base case  1  is shown installed on the casing  21 , with a combustor  12  still installed in the casing. The core of the mounting arrangement  4  comprising of the main cage  2  and the inner structure  3  hangs on the hook  20  of a crane. 
         [0055]    In  FIG. 7   b  the main cage  2  together with the inner structure have been moved above the turbine component  12  (combustor) and the main cage interface  17  can be closed to remove the turbine component  12 . 
         [0056]    It will be appreciated by those skilled in the art that the present disclosure can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restrictive.