Patent Publication Number: US-10787908-B2

Title: Disk assembly for gas turbine compressor

Description:
CROSS-REFERENCE(S) TO RELATED APPLICATIONS 
     This application claims priority to Korean Patent Application No. 10-2017-0015620, filed on Feb. 3, 2017, the disclosure of which is incorporated herein by reference in its entirety. 
     BACKGROUND OF THE DISCLOSURE 
     Field of the Disclosure 
     Exemplary embodiments of the present disclosure relate to a disk assembly for a gas turbine compressor, and more particularly, to a disk assembly for a gas turbine compressor, which comprises a partition wall formed to partition a space between disks for the gas turbine compressor to optimize a cooling fluid path. 
     Description of the Related Art 
     As is widely known, a gas turbine generally comprises a compressor that compresses air, a combustor that mixes the compressed air with fuel for ignition, and a turbine blade assembly that produces electric power. 
     The combustor is operated at a high temperature above 2,500° F. The vane and blade of the turbine are typically exposed to the high temperature, and they are therefore made of a material resistant to high temperature. In addition, the vane and blade of the turbine are provided with a cooling system that prolongs their life and reduces a possibility of damage due to excessive temperature. 
     One of the methods for cooling a turbine section exposed to high temperature using this cooling system is to secure a cooling fluid from a compressor section to supply the cooling fluid to a turbine section. In the compressor of the gas turbine which uses this cooling method, birth parts of each disk are coupled to each other and the disk has an opening formed at a portion thereof to form a passage of cooling air. 
     Cooling air serves to cool the turbine section in such a manner that a portion of the air delivered to the combustor through the compressor is introduced between disk rims which are outer peripheral portions of the disks of the compressor, thereby getting to the turbine section. The cooling air is introduced into a first space between each of the disk rims and an associated one of the birth parts, is introduced into a second space between the hirth part and the center of the associated disk through, the opening, and is delivered to the turbine section through a passage that is formed between a root part of the disk of the compressor and a rotary shaft to extend to the turbine section. 
     SUMMARY OF THE DISCLOSURE 
     However, in this conventional method, cooling air rapidly rotates in the second space along with the rotation of the disks of the compressor. Hence, the rotation of cooling air between the disks substantially interrupts the introduction of air into each disk from outside of the disk. 
     In addition, the disk must be processed to form an opening thereon. However, there is a problem in that this processing is commonly performed using a drill and it is very difficult to process the disk according to the position or direction of the opening. 
     An object, of the present disclosure is to provide a disk assembly for a gas turbine compressor, which comprises corresponding grooves formed at positions in which, facing hirth parts meet each other and a partition wall tor preventing cooling air from rotating in a space between disks. 
     Other objects and advantages of the present disclosure may be understood by the following description, and become apparent with reference to the embodiments of the present disclosure. Also, it is obvious to those skilled in the art to which the present disclosure pertains that the objects and advantages of the present disclosure may be realized by the means as claimed and combinations thereof. 
     In accordance with one aspect of the present disclosure, a disk for a gas turbine compressor comprises a root part assembled to a rotary shaft, a circular base plate extending radially from the root part and having a thickness smaller than that of the root part in a direction of the rotary shaft, a disk rim forming an outer periphery of the base plate and extending bidirectionally in a direction parallel to the direction of the rotary shaft, and a circular birth part protruding bidirectionally from the base plate in the direction parallel to the direction of the rotary shaft and positioned between the root part and the disk rim, wherein the hirth part has a plurality of grooves formed at an end thereof, the grooves being circumferentially spaced apart from each other, and at least one partition wall is formed to extend from the root part to the hirth part. 
     The number of partition walls may be six. 
     The partition walls may be spaced circumferentially at the same distance on the base plate. 
     The partition wall may comprise a bonding portion having the same height as a protruding height of the hirth part from the base plate. 
     The partition wall may further comprise an inclined portion extending from the bonding portion to the root part and having a height gradually lowered. 
     A protruding length of the hirth part in the direction of the rotary shaft from the base plate may be longer than protruding lengths of the disk rim and the root part in the direction of the rotary shaft from the base plate. 
     In accordance with another aspect of the present disclosure, a disk assembly for a gas turbine compressor comprises a first disk and a second disk adjacent to the first disk, each comprising a root part assembled to a rotary shall, a circular base plate extending radially from the root part and having a thickness smaller than that of the root part in a direction of the rotary shaft, a disk rim forming an outer periphery of the base plate and extending bidirectionally in a direction parallel to the direction of the rotary shaft, and a circular birth part protruding bidirectionally from the base plate in the direction, parallel to the direction of the rotary shaft and positioned between the root part and the disk rim, wherein a first hirth part of the first disk is coupled to a second hirth part of the second disk, the first hirth part has a plurality of first grooves formed at an end thereof, the first grooves being circumferentially spaced apart from each other, at least one first partition wall is formed to extend from a first root part to the first hirth part, the second birth part has a plurality of second grooves formed at an end thereof, the second grooves being circumferentially spaced apart from each other, and at least one second partition wall is formed to extend from a second root part to the second hirth part. 
     The first and second grooves may be formed at corresponding positions, and the first and second partition walls may be formed at corresponding positions. 
     The first partition wall may comprise a first bonding portion having the same height as a protruding height of the first hirth part from a first base plate of the first disk, the second partition wall may comprise a second bonding portion having the same height as a protruding height of the second hirth part from a second base plate of the second disk, and the first and second bonding portions may be bonded to each other to block a flow of air in a disk space defined between the coupled first and second birth, parts and the rotary shaft. 
     The first partition wall may further comprise a first inclined portion extending horn the first bonding portion to the first root part and having a height gradually lowered, and the second partition wall may further comprise a second, inclined portion extending from the second bonding portion to the second root pail and having a height gradually lowered. 
     The first partition walls and the second partition walls may each be six. 
     The respective first and second partition walls may be spaced circumferentially at the same distance on respective first and second base plates. 
     A protruding length of the first hirth part in the direction of the rotary shaft from a first base plate of the first disk may be longer than protruding lengths of a first disk rim and the first root part of the first disk in the in the direction of the rotary shaft from the first base plate, and a protruding length of the second hirth part in the direction of the rotary shaft from a second base plate of the second disk may be longer than protruding lengths of a second disk rim and the second root part of the second disk in the in the direction of the rotary shaft from the second base plate. 
     In accordance with a further aspect of the present disclosure, a disk assembly for a gas turbine compressor comprises a first disk and a second disk adjacent to the first disk, each comprising a root part assembled to a rotary shaft, a circular base plate extending radially from the root part and having a thickness smaller than that of the root part in a direction of the rotary shaft, a disk rim forming an outer periphery of the base plate and extending bidirectionally in a direction, parallel to the direction of the rotary shaft, and a circular hirth part protruding bidirectionally from the base plate in the direction parallel to the direction of the rotary shaft and positioned between the root part and the disk rim, wherein an inter-disk is mounted between the first disk and the second disk, and air outside the first and second disks flows between a first root part of the first disk and a second root part of the second disk through a plurality of passages formed, to pass through the inter-disk. 
     The inter-disk may have an opening formed in a center thereof, the opening having a diameter greater than those of the first and second root parts. 
     The inter-disk may comprise an air flow plate having a plurality of passages therein, an outer ring formed on an outer periphery of the air flow plate and having an inlet formal for introduction of air, and an inner ring formed on an inner periphery of the air flow plate and having an outlet formed for discharge of air. 
     The outer ring may be coupled between a first birth part of the first disk and a second hirth part of the second disk. 
     The plurality of passages may be formed obliquely to a radial direction. 
     The plurality of passages may be inclined at an angle of 40° to the radial direction. 
     Partitions may each be provided between the plurality of passages. 
     It is to be understood that both the foregoing general description and the following detailed description of the present disclosure are exemplary and explanatory and are intended to provide farther explanation of the disclosure as claimed. 
    
    
     
       BRIEF DESCRIPTION Of THE DRAWINGS 
       The above and other objects, features and other advantages of the present disclosure will be more clearly understood from the following detailed description taken, in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a cross-sectional view schematically illustrating an upper half of an overall gas turbine; 
         FIG. 2  is a view for explaining a state, in which compressed air in a disk space rotates, and calculation of its energy in a disk assembly for a gas turbine compressor in which a through-passage for a flow of a cooling fluid is not formed in a disk; 
         FIG. 3  is a view for explaining a state, in which compressed air in a disk space rotates, and calculation of its energy in a disk assembly for a gas turbine compressor in which a through-passage for a flow of a cooling fluid is formed in a disk; 
         FIG. 4  is a view for explaining a state, in which compressed air in a disk space rotates, and calculation of its energy in a disk assembly for a gas turbine compressor according to an embodiment of the present disclosure; 
         FIG. 5  is a perspective view illustrating one surface of one disk comprised in the disk assembly for a gas turbine compressor according to the embodiment of the present disclosure; 
         FIG. 6  is a cross-sectional view taken along line F-F of  FIG. 5  in the disk assembly for a gas turbine compressor according to the embodiment of the present disclosure; 
         FIG. 7  is a perspective view illustrating an inter-disk according to an embodiment of the present disclosure; 
         FIG. 8  is a cross-sectional view taken along line G-G of  FIG. 7  in the inter-disk according to the embodiment of the present disclosure; and 
         FIG. 9  is a cross-sectional view taken along line H-H of  FIG. 8  in the disk assembly comprising the inter-disk according to the embodiment of the present disclosure. 
     
    
    
     DESCRIPTION OF SPECIFIC EMBODIMENTS 
     Reference will now be made in detail to exemplary embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. The present disclosure may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art. Throughout the disclosure, like reference numerals refer to like parts throughout the various figures and embodiments of the present disclosure. 
     Hereinafter, a disk assembly tor a gas turbine compressor according to exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. 
       FIG. 1  is a cross-sectional view schematically illustrating an upper half of a gas turbine  1 . The gas turbine  1 , comprises an intake section A, a compressor section B, a combustor section C, and a turbine section D. Air introduced through the intake section A is compressed by the blade and vane of the compressor section B, and the compressed air is supplied to the combustor section C. The supplied air is combusted in the combustor section C is delivered to the turbine section D in a high-temperature and high-pressure state. Thus, the rotor of the turbine section D is rotated and the generator connected thereto is operated. 
     In this case, the blade and vane of the turbine section D are continuously exposed to heat, resulting in damage due to heat. To prevent this damage, it may necessary to supply a cooling fluid to the blade and the vane. 
     The gas turbine  1  according to the present disclosure utilizes a method in which a portion of the air compressed by a compressor flows into disks of the compressor to move to the turbine section D along a rotary shaft and is then delivered to a targeted blade  30  and vane  40  of the turbine. 
     To deliver a cooling fluid to the blade and vane of the turbine, it may be important for the cooling fluid to smoothly flow between the rotating disks of the compressor. In this regard, it may be expected that how much introduced air is blocked by each model by calculating kinetic energy of air rotating in a disk space in  FIGS. 2 and 3 . 
       FIG. 2  is a view for explaining a state, in which compressed air in a disk space rotates, and calculation of its energy in a disk assembly for a gas turbine compressor. 
     A disk space is defined in an interior portion in which two base plates  14  face each other between a hirth part  12  and a root part  13  of a disk  10 . Air is contained in the disk space by the volume thereof. For a disk model with a radius PI of 0.57 m (meter) to the hirth part  12 , the rotational velocity y of compressed air is about 213.6 m/s, the centrifugal force P 4  thereof is about 408,223.3 kg·m/s 2 , and the kinetic energy thereof is about 1,392,041.5 J. 
       FIG. 3  is a view for explaining a state, in which the compressed air in the disk space rotates, and calculation of its energy in a disk assembly for a gas turbine compressor according to the present, disclosure. This disk model has a plurality of openings for communication between the hirth part  12  and a portion adjacent to the outer periphery of the root part  13 . In the disk model, air is introduced into each of the openings from outside of the opening, and a disk space has a radius Q 1  of 0.35 m set smaller than that of  FIG. 2 . 
     The disk space is defined in an interior portion in which, the two base plates  14  face each other. The disk space has the radius Q 1  of 0.35 m to the outer periphery thereof. Air is contained in the disk space by the volume thereof. For the disk model with the radius Q 1  of 0.35 m, the rotational velocity v of compressed air is about 132 m/s, the centrifugal force Q 4  thereof is about 73,180.8 kg·m/s 2 , and the kinetic energy thereof is about 160,264 J. 
     When the disk space is reduced or the amount of rotation of air is reduced while the path of air introduced into the disk is secured, the kinetic energy of rotating air is reduced to interrupt the introduction of air less in the case of the disk model of  FIG. 3  than that of  FIG. 2 . The model of  FIG. 4  has been devised based on these models. 
       FIG. 4  is a view for explaining a state, in which compressed air in a disk space rotates, and calculation of its energy in a disk assembly for a gas turbine compressor according to an embodiment of the present disclosure. 
     In the embodiment, the disk  10  is entirely outlined based on the disk model of  FIG. 2 . Additionally, a plurality of grooves  21  is formed in the hirth part  12  and partition walls  22  extending radially are formed between the hirth part  12  and the root part  13 . 
     In such a configuration, a space, which has a radius R 1  of 0.57 m and is defined between the two base plates  14 , is equally partitioned into six by the partition walls  22 . The air present in the equally partitioned, spaces has a mass R 2  of about 0.85 kg, and the rotatably movable distance R 3  of air is 0.56 m. In this case, the rotational velocity v of compressed air is about 213.6 m/s, the centrifugal force R 4  thereof is about 68,037.2 kg·m/s 2 , where the value is obtained by multiplying the mass E 2  by the square of the velocity v and then dividing the same by the radius R 1 , and the kinetic energy thereof is about 38,100.8 J. 
     According to the embodiment of the present disclosure, the centrifugal force and kinetic energy of air are significantly reduced. Therefore, the compressed air introduced from the plurality of grooves  21  may smoothly flow into the disk. 
       FIG. 5  is a perspective view illustrating a surface of one disk comprised in the disk assembly for a gas turbine compressor, according to the embodiment of the present disclosure. 
     A disk rim  11  forms the outer periphery of the disk  10 . The blade  30  may be mounted on an outer surface  15  of the disk rim  11 , but this mounting structure is omitted for explaining only a structure of the disk in the drawing. 
     The root part  13  has an opening formed in the center thereof for insertion of a rotary shaft. The opening of the root part  13  may be defined by an inner surface  16  of the root part  13 . The basic frame of the disk is completed by forming a base plate  14  having a surface extending radially from the root part  13 , which is mounted on the rotary shaft, to the disk rim  11 . The hirth part  12  is formed between the disk rim  11  and the root part  13 , and is coupled to a hirth past of an adjacent disk. 
     A plurality of partition walls may be ionised between the root part  13  and the hirth part  12 . Each of the partition walls extends radially between the root part  13  and the hirth part  12 . 
     In the disk assembly according to the embodiment of the present disclosure, the plurality of partition walls may be six partition walls  22  arranged in the same distance. In the ease where the plurality of partition walls are six as in the present embodiment, the disk assembly may have an excellent effect of balancing the flow of a cooling fluid without an excessive increase in weight. That is, since the kinetic energy of air rotating between a disk and another disk and between a partition wall and another partition wall is reduced to about 38,100.8 J as in the above experimental result while the weight of the disk assembly is minutely increased, it may be possible to minimize a pressure loss of compressed air passing through the disk from outside to inside. Each of the disk rim  11 , the root part  13 , and the hirth part  12  therebetween has a shape protruding from the base plate  14 . However, the disk rim  11  as an outer peripheral portion and the root part  13  as a center portion are lower in height than the hirth part  12  serving as a coupling portion between the disks. Preferably, each of the partition walls  22  extending to the root part  13  at the same height as the hirth part  12  comprises a bonding portion  23 , which has the same height as the hirth part  12 , and an inclined portion  24  which is gradually lowered to the height of the root part  13 . 
     In detail, one end of the partition wall  22  is connected to an inclined surface of the root part  13  and the other end thereof is connected to the inner surface of the hirth part  12 . However, since the height from the point, at which the inclined surface  18  of the root part  13  meets an upper surface  17  of the root pan  13 , to a center line T of the base plate  14  is lower than the height from the bonding portion  23  to the center line T, the inclined portion  24  is required to compensate for a difference in height. In this case, the bonding portion  23  is a necessary component to prevent rotation of air, whereas the inclined portion  24  is a subsidiary component. 
       FIG. 6  is a cross-sectional view taken along line F-F of  FIG. 5  in the disk assembly for a gas turbine compressor according to the embodiment of the present disclosure. In the disk assembly, a first disk  10   a  is adjacent to a second disk  10   b , hirth parts  12   a  and  12   b  are coupled to each other, and a first groove  21   a  of the first disk  10   a  meets a second groove  21   b  of the second disk  10   b  to form an opening. Compressed air is introduced into the disks from outside of the disks in the direction indicated by a dotted arrow  5 . The air introduced into the disk space immediately flows between upper surfaces  17   a  and  17   b  of root parts  13   a  and  13   b  to flow to the turbine section through a cooling passage  4  in the direction indicated by an arrow  5 ′, and is in the state in which the rotation of the air is restricted by first and second partition walls  22   a  and  22   b.    
     The distance S 1  from a center line T to the end of a disk rim  11   a  may be slightly shorter than the distance S 2  from the center line T to the end of the hirth part  12   a  to form a space for introduction of air. 
     The distance S 3  from the center line T to the end of the root part  13   a  may be slightly shorter than the distance S 2  from the center line T to the end of the hirth part  12   a  to form a space for discharge of air. 
     The disks  10   a  and  10   b  are assembled to a rotary shaft by a fastener  50 , and the cooling passage  4  is formed between the rotary shaft and the root part of each disk and extends to the turbine section. 
       FIG. 7  is a perspective view illustrating an inter-disk  100  according to an embodiment of the present disclosure. The inter-disk  100  is mounted in the disk space between the first disk  10   a  and the second disk  30   b  to prevent rotation of compressed air. In the embodiment, the inter-disk  100  is inserted into the disk space to reduce rotation of air, unlike the embodiment of  FIGS. 4 to 6  in which the shape of the disk  10  is modified. 
     The inter-disk  100  has an opening  119  formed in the center thereof, and the opening  119  has a diameter greater than the outer diameter of the upper surface  17   a  or  17   b  of the root part  13   a  or  13   b  of each disk  10   a  or  10   b . This may enable the air in the disk to be much less affected by the rotation of the compressor in such a manner that, when compressed air is delivered from inlets  121   a  formed on an outer peripheral surface  115  of the inter-disk  100  to outlets  121   b  formed on an inner peripheral surface  116 , the air is immediately supplied to the root part  13   a  or  13   b  as a center portion of the disk. 
     The inter-disk  100  comprises an air flow plate  114  that has a plurality of passages  121  therein; an inner ring  113  that is formed on the inner periphery of the air flow plate  114 , defines the boundary of the opening  119 , and has outlets  121   b  formed thereon; and an outer ring  112  that is formed on the outer periphery of the air flow plate  114  and has inlets  121   a  formed thereon. 
       FIG. 8  is a cross-sectional view taken along line G-G of  FIG. 7  in the inter-disk according to the embodiment of the present disclosure. 
     The outer ring  112  of the inter-disk  100  is coupled between the first hirth part  12   a  of the first disk  10   a  and the second hirth part  12   b  of the second disk  10   b . In this case, their coupling may be spline-coupling, similar to typical coupling between hirth parts. 
     Preferably, the plurality of passages  121  are formed obliquely to the radial direction in the air flow plate  114  of the inter-disk  100 . Preferably, each of the passages  121  has an angle of inclination α of 40° to the radial direction. This is to consider the flow path of air according to the rotation of the compressor. When the angle of inclination α of the passage is 40°, a pressure drop becomes minimum. 
     Each of the passages  121  may be processed in a slot form to secure the stable structure of the inter-disk  100 . The plurality of passages  121  are preferably formed, and the number of the passages  121  is ten (10) in one example. 
     Partitions  122  are formed between the passages  121 , and the number of partitions is necessarily equal to the number of passages. 
       FIG. 9  is a cross-sectional view taken along line H-H of  FIG. 8  in the disk assembly comprising the inter-disk according to the embodiment of the present disclosure. 
     Compressed air flows through the passages  121  of the inter-disk  100  from the outside of the disk  10   a  or  10   b  in the direction indicated by an arrow  5 . Then, the air is supplied to the turbine section D through a cooling passage  4  formed between the disk  10   b  and the rotary shaft. 
     The outer ring of the inter-disk  100  is spline-coupled between the hirth parts  12   a  and  12   b  of the disks  10   a  and  10   b . The inner ring  113  has outlets  121   b  formed therein, and the inner periphery of the inner ring  113  is further away from the rotary shaft than the point at which the upper surfaces  17   a  and  17   b  of both root parts  13   a  and  13   b  meet the inclined surfaces  18   a  and  18   b.    
     Since the outlets  121   b  are formed adjacent to the upper surfaces  17   a  and  17   b , the compressed air passing through the passages  121  may immediately flow to the cooling passage  4 . This structure may significantly reduce a pressure loss of compressed air. 
     As is apparent from the above description, a disk assembly for a gas turbine compressor according to exemplary embodiments of the present disclosure may prevent a cooling fluid from rotating in a space between disks to promote the introduction of cooling air into each of the disks from outside of the disk. 
     In addition, the disk assembly for a gas turbine compressor is advantageous in that it may be easily manufactured since an opening for communication of a cooling fluid is not separately processed in the disk. 
     While the present disclosure has been described with respect to the specific embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the disclosure as defined in the following claims.