Patent Grant
10670039
The present application claims priority based on Japanese Patent Application No. 2015-090289 filed on Apr. 27, 2015, the contents of which are incorporated herein by reference.
The present invention relates to a compressor rotor that rotates along an axis inside a compressor casing, a compressor, and a gas turbine.
A compressor includes a casing and a rotor that rotates around an axis inside the casing. A rotor of an axial-flow compressor has a rotor shaft that extends around an axis in an axial direction, and a plurality of blade rows that are fixed to an outer circumference of the rotor shaft and arrayed in the axial direction.
Examples of such a rotor of an axial-flow compressor include the one disclosed in Japanese Patent Publication No. 2013-204593. In this rotor, a plurality of chambers (or cavities) are formed for the purpose of rotor weight reduction etc. Of the plurality of chambers, a first chamber and a second chamber are located side by side in the axial direction at the same position in the radial direction. The second chamber is located on the upstream side in the axial direction relative to the first chamber. Of the plurality of chambers, a third chamber is formed at a position between the first chamber and the second chamber in the axial direction, on the radially inner side of the first chamber and the second chamber. Both the first chamber and the second chamber communicate with an air compression flow passage that is formed by an annular space between the outer circumferential side of the rotor shaft and the inner circumferential side of the casing. The third chamber communicates with both the first chamber and the second chamber.
Part of air inside the air compression flow passage flows into the first chamber that is located on the downstream side of the second chamber. This air flows from the first chamber into the third chamber, and then returns into the air compression flow passage through the second chamber.
Patent Literature 1: Japanese Patent Laid-Open No. 2013-204593
The technique disclosed in Japanese Patent Publication No. 2013-204593 enhances the thermal responsiveness of the rotor shaft to changes in temperature of air flowing through the air compression flow passage by passing part of the air inside the air compression flow passage through the chambers and returning this air into the air compression flow passage.
An object of the present invention is to provide a compressor rotor that can further enhance the thermal responsiveness of the rotor shaft to changes in temperature of gas flowing through the gas compression flow passage, a compressor including this compressor rotor, and a gas turbine including this compressor.
A compressor rotor as a first aspect according to the present invention to achieve the above object is a compressor rotor that rotates around an axis inside a compressor casing, and includes a rotor shaft that extends around the axis in an axial direction, and a plurality of blade rows that are fixed to an outer circumference of the rotor shaft and arrayed in the axial direction. A cavity group composed of a plurality of cavities that each have an annular shape around the axis and are separated from one another in a radial direction of the axis is formed inside the rotor shaft at each position between adjacent ones of the plurality of blade rows in the axial direction. A side on which a pressure of gas flowing through a gas compression flow passage is low constitutes an upstream side in the axial direction, and a side which is the opposite side from the upstream side and on which the pressure of the gas is high constitutes a downstream side in the axial direction, the gas compression flow passage being located on an outer circumferential side of the rotor shaft and being where the plurality of blade rows are present in the axial direction. Of the plurality of cavities composing the cavity group, a cavity located farthest on a radially outer side constitutes an outer cavity, and another cavity located on a radially inner side of the outer cavity constitutes an axial communication cavity. Of at least two cavity groups, one or more cavity groups located on the upstream side constitute upstream-side cavity groups, and the other cavity groups located on the downstream side relative to the upstream-side cavity groups constitute downstream-side cavity groups. The rotor shaft further has: an inlet flow passage through which the gas inside the gas compression flow passage flows into the outer cavity of the downstream-side cavity group; a radial flow passage that extends in a direction including the radial direction, and provides communication between two cavities adjacent to each other in the radial direction among the plurality of cavities from the outer cavity to the axial communication cavity of the downstream-side cavity group, so that the gas having flowed into the outer cavity of the downstream-side cavity group reaches the axial communication cavity of the downstream-side cavity group; an axial flow passage that extends in a direction including the axial direction, and provides communication between the axial communication cavity of the downstream-side cavity group and the axial communication cavity of the upstream-side cavity group; a radial flow passage that extends in a direction including the radial direction, and provides communication between two cavities adjacent to each other in the radial direction among the plurality of cavities from the axial communication cavity to the outer cavity of the upstream-side cavity group, so that the gas inside the axial communication cavity of the upstream-side cavity group reaches the outer cavity of the upstream-side cavity group; and an outlet flow passage through which the gas inside the outer cavity of the upstream-side cavity group flows out into the gas compression flow passage. A radially outer-side edge of an inlet opening that is an opening of the axial flow passage to the axial communication cavity of the downstream-side cavity group is located on the radially inner side of a radially outer-side inner circumferential surface of inner circumferential surfaces defining the annular axial communication cavity. A radially outer-side edge of an outlet opening that is an opening of the axial flow passage to the axial communication cavity of the upstream-side cavity group is located on the radially inner side of a radially outer-side inner circumferential surface of inner circumferential surfaces defining the annular axial communication cavity.
In this compressor rotor, a pressure difference in the axial direction inside the gas compression flow passage is used as a driving force to allow part of the gas inside the gas compression flow passage to flow into the outer cavity of the downstream-side cavity group through the inlet flow passage. The gas having flowed into the outer cavity flows into the axial communication cavity of the downstream-side cavity group through the radial flow passage, and in some cases, further through one or more cavities. The gas having flowed into the axial communication cavity of the downstream-side cavity group flows into the axial communication cavity of the upstream-side cavity group through the axial flow passage. The gas having flowed into the axial communication cavity of the upstream-side cavity group flows into the outer cavity of the upstream-side cavity group through the radial flow passage, and in some cases, further through one or more cavities. The gas having flowed into the outer cavity of the upstream-side cavity group returns to the gas compression flow passage through the outlet flow passage.
Thus, in this compressor rotor, the pressure difference in the axial direction inside the air compression flow passage can be used as a driving force to efficiently ventilate the inside each of the outer cavity of the downstream-side cavity group, the cavity between the outer cavity and the axial communication cavity of the downstream-side cavity group, the outer cavity of the upstream-side cavity group, and the cavity between the outer cavity and the axial communication cavity of the upstream-side cavity group, with part of the gas inside the gas compression flow passage. Moreover, in this compressor rotor, the part of the axial communication cavity of the downstream-side cavity group from the radially outer-side edge to a position in the radial direction at which the axial flow passage is open, and the part of the axial communication cavity of the upstream-side cavity group from the radially outer-side edge to a position in the radial direction at which the axial flow passage is open can also be efficiently ventilated with the gas inside the gas compression flow passage. Furthermore, in this compressor rotor, the heat transfer coefficient of wall surfaces defining the cavities can be increased using a difference in circumferential velocity between the cavities and the air flowing through the cavities.
Thus, in this compressor rotor, the thermal responsiveness of the compressor rotor to changes in temperature of the gas flowing through the gas compression flow passage can be enhanced.
A compressor rotor as a second aspect according to the present invention to achieve the above object is the compressor rotor of the first aspect, wherein the radially outer-side edge of the inlet opening of the axial flow passage is located on the radially inner side of a center position in the radial direction of the axial communication cavity of the downstream-side cavity group, and the radially outer-side edge of the outlet opening of the axial flow passage is located on the radially inner side of a center position in the radial direction of the axial communication cavity of the upstream-side cavity group.
In this compressor rotor, the inside of the axial communication cavity of the downstream-side cavity group and the inside of the axial communication cavity of the upstream-side cavity group can be ventilated extensively and efficiently with the gas inside the gas compression flow passage. Moreover, in this compressor rotor, the heat transfer coefficient of the wall surfaces defining the cavities can be increased using the difference in circumferential velocity between the cavities and the air flowing through the cavities. Thus, in this compressor rotor, the thermal responsiveness of the compressor rotor to changes in temperature of the gas flowing through the gas compression flow passage can be further enhanced.
A compressor rotor as a third aspect according to the present invention to achieve the above object is the compressor rotor of the first or second aspect, wherein the rotor shaft has a plurality of the axial flow passages that are separated from one another in a circumferential direction of the axis.
In this compressor rotor, the circumferential velocity of the gas flowing through the axial flow passage is restricted by the circumferential velocity of the rotor shaft, and thus becomes substantially equal to the circumferential velocity of the rotor shaft. On the other hand, as the axial communication cavities communicating with the axial flow passage are formed annularly around the axis, the circumferential velocity of the gas flowing through these axial communication cavities is basically not restricted by the circumferential velocity of the rotor shaft. Accordingly, the circumferential velocity of the gas flowing through the axial communication cavities differs from the circumferential velocity of the rotor shaft. In particular, the difference in circumferential velocity from the rotor shaft is larger on the radially outer side than on the radially inner side inside the axial communication cavity of the upstream-side cavity group. Accordingly, the heat transfer coefficient between the air and a surface of a constituent member of the rotor shaft defining the cavity can be increased.
Thus, in this compressor rotor, the thermal responsiveness of the compressor rotor to changes in temperature of the gas flowing through the gas compression flow passage can be further enhanced.
A compressor rotor as a fourth aspect according to the present invention to achieve the above object is the compressor rotor of any one of the first to third aspects, including at least one of the following inlet-side parts: an inlet-side part of the radial flow passage of the upstream-side cavity group including an inlet opening that is a radially inner-side opening and is inclined toward a rotation direction side of the rotor shaft; and an inlet-side part of the axial flow passage including an inlet opening that is inclined toward the opposite side from the rotation direction side of the rotor shaft.
In one of the above compressor rotors, at least one of the following inlet-side parts may be inclined toward the rotation direction side of the rotor shaft: an inlet-side part of the radial flow passage that provides communication between the outer cavity of the downstream-side cavity group and the cavity adjacent to the outer cavity in the radial direction, the inlet-side part including an inlet opening that is a radially outer-side opening of the radial flow passage; and an inlet-side part of the radial flow passage of the upstream-side cavity group including an inlet opening that is a radially inner-side opening of the radial flow passage.
In one of the above compressor rotors, the inlet-side part of the axial flow passage including the inlet opening of the axial flow passage may be inclined toward the opposite side from the rotation direction side of the rotor shaft.
A compressor rotor as a fifth aspect according to the present invention to achieve the above object is the compressor rotor of any one of the first to fourth aspects, wherein the downstream-side cavity group has three or more cavities, and, in the radial flow passage that provides communication between two or more cavities of the three or more cavities except for the outer cavity, an inlet-side part of the radial flow passage including an inlet opening that is a radially outer-side opening is inclined toward the opposite side from the rotation direction side of the rotor shaft.
In this compressor rotor, even when there is a difference in circumferential velocity between the gas and the flow passage, this gas is faced and received by the inlet opening of the flow passage, so that the gas can flow smoothly into the flow passage.
A compressor rotor as a sixth aspect according to the present invention to achieve the above object is the compressor rotor of any one of the first to fifth aspects, wherein at least one of the following outlet-side parts may be inclined toward the rotation direction side of the rotor shaft or toward the opposite side from the rotation direction side of the rotor shaft: an outlet-side part of the radial flow passage of the downstream-side cavity group including an outlet opening that is a radially inner-side opening of the radial flow passage; an outlet-side part of the radial flow passage of the upstream-side cavity group including an outlet opening that is a radially outer-side opening of the radial flow passage; and an outlet-side part of the axial flow passage including the outlet opening of the axial flow passage.
A compressor rotor as a seventh aspect according to the present invention to achieve the above object is the compressor rotor of any one of the first to sixth aspects, wherein a flow passage inside diameter of an inlet-side part of a flow passage including the inlet opening decreases gradually in a direction from the inlet opening toward an outlet opening located on the opposite side of the flow passage from the inlet opening.
A compressor rotor as an eighth aspect according to the present invention to achieve the above object is the compressor rotor of any one of the first to seventh aspects, wherein the rotor shaft has a plurality of rotor discs stacked in the axial direction, and a torque pin that extends in the radial direction and engages with each of two rotor discs adjacent to each other in the axial direction to restrain the adjacent rotor discs from rotating relative to each other; the torque pin is disposed at positions between the cavities adjacent to each other in the radial direction among the plurality of cavities composing the downstream-side cavity group, and at positions between the cavities adjacent to each other in the radial direction among the plurality of cavities composing the upstream-side cavity group; and the torque pin has a through-hole that extends through the torque pin in the radial direction, and the through-hole forms the radial flow passage.
In this compressor rotor, forming the through-hole in the torque pin can eliminate the need for forming the radial flow passage in the rotor disc. Thus, in this compressor rotor, an increase in the number of processes on the rotor disc can be avoided.
A compressor rotor as a ninth aspect according to the present invention to achieve the above object is the compressor rotor according to any one of the first to eighth aspects, wherein the rotor shaft has a plurality of rotor discs that are stacked in the axial direction, and a spindle bolt that extends in the axial direction through the plurality of rotor discs, the axial communication cavity of the downstream-side cavity group, and the axial communication cavity of the upstream-side cavity group; there is a gap extending in the axial direction left between the spindle bolt and a bolt through-hole which is formed in the rotor disc present between the axial communication cavity of the downstream-side cavity group and the axial communication cavity of the upstream-side cavity group and through which the spindle bolt extends; and the gap in the bolt through-hole forms the axial flow passage.
A compressor rotor as a tenth aspect according to the present invention to achieve the above object is the compressor rotor of the ninth aspect, wherein the gap in the bolt through-hole that forms the axial flow passage is located on the radially inner side of the spindle bolt.
A compressor rotor as an eleventh aspect according to the present invention to achieve the above object is the compressor rotor of any one of the first to tenth aspects, wherein the cavity located farthest on the radially inner side of the plurality of cavities composing the cavity group forms the axial communication cavity.
In this compressor rotor, the inside of all the plurality of cavities composing the cavity group can be efficiently ventilated with the gas inside the gas compression flow passage. Thus, in this compressor rotor, the thermal responsiveness of the compressor rotor to changes in temperature of the gas flowing through the gas compression flow passage can be further enhanced.
A compressor rotor as a twelfth aspect according to the present invention to achieve the above object is the compressor rotor according to any one of the first to eleventh aspects, wherein, of two cavity groups adjacent to each other in the axial direction, the cavity group located on the upstream side constitutes an upstream-side cavity group, and the cavity group located on the downstream side constitutes a downstream-side cavity group.
A compressor as a thirteenth aspect according to the present invention to achieve the above object includes the compressor rotor of any one of the first to twelfth aspects, and the compressor casing.
A gas turbine as a fourteenth aspect according to the present invention to achieve the above object includes: the compressor of the thirteenth aspect; a combustor that generates combustion gas by combusting fuel in air compressed by the compressor; and a turbine that is driven by the combustion gas.
According to one aspect of the present invention, the thermal responsiveness of the rotor shaft to changes in temperature of gas flowing through the gas compression flow passage can be further enhanced.
Various embodiments according to the present invention will be described below in detail with reference to the drawings.
An embodiment of a gas turbine will be described with reference to
As shown in
The compressor 1 has a compressor rotor 20 that rotates around an axis Ar, and a cylindrical compressor casing 10 that covers the compressor rotor 20. Hereinafter, a direction in which the axis Ar extends will be referred to as an axial direction Da. One side in the axial direction Da and the other side in the axial direction will be referred to as an upstream side and a downstream side, respectively. A radial direction based on the axis Ar will be referred to simply as a radial direction Dr. A side farther away from the axis Ar in the radial direction Dr and a side closer to the axis Ar in the radial direction Dr will be referred to as a radially outer side and a radially inner side, respectively. An opening is formed on the upstream side of the compressor casing 10. This opening constitutes an intake opening 11i through which the compressor 1 takes in air from the outside.
The turbine 3 is disposed on the downstream side of the compressor 1. The turbine 3 has a turbine rotor 4 that rotates around the axis Ar, and a cylindrical turbine casing 5 that covers the turbine rotor 4. The compressor rotor 20 and the turbine rotor 4 rotate around the same axis Ar, and are coupled together to form a gas turbine rotor 8. The compressor casing 10 and the turbine casing 5 are coupled together to constitute a gas turbine casing 9. The combustor 2 is fixed to the gas turbine casing 9.
A first embodiment of a compressor will be described with reference to
The compressor of this embodiment is the compressor 1 of the gas turbine described above. Therefore, the compressor 1 of this embodiment has the compressor rotor 20 that rotates around the axis Ar, and the cylindrical compressor casing 10 that covers the compressor rotor 20.
As shown in
One vane row 11 has a plurality of vanes 12. The plurality of vanes 12 are arrayed in the circumferential direction Dc around the axis Ar and compose one vane row 11. One blade row 81 has a plurality of blades 82. The plurality of blades 82 are arrayed in the circumferential direction Dc around the axis Ar and compose one blade row 81.
As shown in
An air compression flow passage 19 of the compressor 1 through which air in a compression process passes has an annular shape around the axis Ar. The outer circumferential side of the air compression flow passage 19 is defined by the compressor casing 10 and the outer shrouds 14 of the vanes 12. The inner circumferential side of the air compression flow passage 19 is defined by the platforms 84 of the blades 82 and the inner shrouds 15 of the vanes 12. As the compressor rotor 20 rotates, air flows through the air compression flow passage 19 from the upstream side to the downstream side while being compressed.
As shown in
One cavity group 22 is composed of three cavities: an outer cavity 24, an intermediate cavity 25, and an inner cavity 26. Of the plurality of cavities, the outer cavity 24 is formed farthest on the outer side in the radial direction Dr inside the rotor shaft 21. The intermediate cavity 25 is formed on the inner side in the radial direction Dr of the outer cavity 24. Of the plurality of cavities, the inner cavity 26 is formed farthest on the inner side in the radial direction Dr inside the rotor shaft 21.
The rotor shaft 21 further has a radially outer flow passage 34 that provides communication between the outer cavity 24 and the air compression flow passage 19, and a plurality of radially intermediate flow passages 35 that provide communication between the outer cavity 24 and the intermediate cavity 25. The radially outer flow passage 34 is a flow passage that extends annularly around the axis Ar. The plurality of radially intermediate flow passages 35 are separated from one another in the circumferential direction Dc.
The rotor shaft 21 has a plurality of rotor discs 41, spindle bolts 51, and torque pins 55. The plurality of rotor discs 41 are stacked in the axial direction Da. The spindle bolt 51 extends through the plurality of rotor discs 41 and the plurality of intermediate cavities 25 in the axial direction Da. The torque pin 55 restrains the adjacent rotor discs 41 from rotating relative to each other.
One blade row 81 is mounted on each rotor disc 41. Thus, there are the rotor discs 41 respectively for the plurality of blade rows 81.
As shown in
On the upstream side of one rotor disc 41, an upstream-side first recess 43u, an upstream-side second recess 45u, and an upstream-side third recess 47u are formed. The upstream-side first recess 43u is recessed toward the downstream side to form the outer cavity 24 on the upstream side of this rotor disc 41. The upstream-side second recess 45u is recessed toward the downstream side to form the intermediate cavity 25 on the upstream side of this rotor disc 41. The upstream-side third recess 47u is recessed toward the downstream side to form the inner cavity 26 on the upstream side of this rotor disc 41. Thus, on the outer side in the radial direction Dr of the upstream-side first recess 43u, an annular upstream-side first arm 42u is formed that protrudes toward the upstream side in the axial direction Da relative to a bottom surface of the upstream-side first recess 43u. Between the upstream-side first recess 43u and the upstream-side second recess 45u, an annular upstream-side second arm 44u is formed that protrudes toward the upstream side in the axial direction Da relative to the bottom surface of the upstream-side first recess 43u and a bottom surface of the upstream-side second recess 45u. Between the upstream-side second recess 45u and the upstream-side third recess 47u, an annular upstream-side third arm 46u is formed that protrudes toward the upstream side in the axial direction Da relative to the bottom surface of the upstream-side second recess 45u and a bottom surface of the upstream-side third recess 47u.
The annular upstream-side second arm 44u has a plurality of upstream-side pin grooves 44up that are recessed toward the downstream side and provide communication between the upstream-side first recess 43u and the upstream-side second recess 45u.
On the downstream side of one rotor disc 41, a downstream-side first recess 43d, a downstream-side second recess 45d, and a downstream-side third recess 47d are formed. The downstream-side first recess 43d is recessed toward the upstream side to form the outer cavity 24 on the downstream side of this rotor disc 41. The downstream-side second recess 45d is recessed toward the upstream side to form the intermediate cavity 25 on the downstream side of this rotor disc 41. The downstream-side third recess 47d is recessed toward the upstream side to form the inner cavity 26 on the downstream side of this rotor disc 41. Thus, on the outer side in the radial direction Dr of the downstream-side first recess 43d, an annular downstream-side first arm 42d is formed that protrudes toward the downstream side in the axial direction Da relative to a bottom surface of the downstream-side first recess 43d. Between the downstream-side first recess 43d and the downstream-side second recess 45d, an annular downstream-side second arm 44d is formed that protrudes toward the downstream side in the axial direction Da relative to the bottom surface of the downstream-side first recess 43d and a bottom surface of the downstream-side second recess 45d. Between the downstream-side second recess 45d and the downstream-side third recess 47d, an annular downstream-side third arm 46d is formed that protrudes toward the downstream side in the axial direction Da relative to the bottom surface of the downstream-side second recess 45d and a bottom surface of the downstream-side third recess 47d.
The annular downstream-side second arm 44d has a plurality of downstream-side pin grooves 44dp that are recessed toward the upstream side and provide communication between the downstream-side first recess 43d and the downstream-side second recess 45d.
The outer cavity 24 is defined by the downstream-side first recess 43d of one rotor disc 41, located on the upstream side, of two rotor discs 41 adjacent to each other in the axial direction Da, and by the upstream-side first recess 43u of the other rotor disc 41 located on the downstream side. The intermediate cavity 25 is defined by the downstream-side second recess 45d of one rotor disc 41, located on the upstream side, of two rotor discs 41 adjacent to each other in the axial direction Da, and by the upstream-side second recess of the other rotor disc 41 located on the downstream side. The inner cavity 26 is defined by the downstream-side third recess 47d of one rotor disc 41, located on the upstream side, of two rotor discs 41 adjacent to each other in the axial direction Da, and by the upstream-side third recess 47u of the other rotor disc 41 located on the downstream side.
The downstream-side first arm 42d of one rotor disc 41, located on the upstream side, of two rotor discs 41 adjacent to each other in the axial direction Da, and the upstream-side first arm 42u of the other rotor disc 41 located on the downstream side face each other and are separated from each other in the axial direction Da. The radially outer flow passage 34 is defined by the downstream-side first arm 42d of one rotor disc 41, located on the upstream side, of two rotor discs 41 adjacent to each other in the axial direction Da, and by the upstream-side first arm 42u of the other rotor disc 41 located on the downstream side.
The plurality of downstream-side pin grooves 44dp of one rotor disc 41, located on the upstream side, of two rotor discs 41 adjacent to each other in the axial direction Da, and the plurality of upstream-side pin grooves 44up of the other rotor disc 41 located on the downstream side face each other in the axial direction Da. Pin holes in which the torque pins 55 are mounted are defined by the downstream-side pin grooves 44dp and the upstream-side pin grooves 44up. The pin holes in which the torque pins 55 are mounted each have a columnar shape corresponding to the shape of the columnar torque pin 55.
The rotor disc 41 has bolt through-holes 48 which each extend through the rotor disc 41 from the bottom surface of the upstream-side second recess 45u to the bottom surface of the downstream-side second recess 45d and through which the spindle bolts 51 are inserted. A blade mounting part 49 in which the blade root 85 (see
As shown in
As shown in
The radially outer flow passage 34 that provides communication between the outer cavity 24 of the downstream-side cavity group 22d and the air compression flow passage 19 constitutes an inlet flow passage 34d through which air inside the air compression flow passage 19 flows into the outer cavity 24. The radially outer flow passage 34 that provides communication between the outer cavity 24 of the upstream-side cavity group 22u and the air compression flow passage 19 constitutes an outlet flow passage 34u through which air inside the outer cavity 24 flows out into the air compression flow passage 19.
In the rotor disc 41 between the downstream-side cavity group 22d and the upstream-side cavity group 22u, axial flow passages 37 are formed that provide communication between the intermediate cavity 25 of the downstream-side cavity group 22d and the intermediate cavity 25 of the upstream-side cavity group 22u. As shown in
Thus, in this embodiment, the axial flow passages 37 are formed that provide communication between the intermediate cavity 25 of the downstream-side cavity group 22d and the intermediate cavity 25 of the upstream-side cavity group 22u. In this embodiment, therefore, both the intermediate cavity 25 of the downstream-side cavity group 22d and the intermediate cavity 25 of the upstream-side cavity group 22u constitute axial communication cavities. In the rotor disc 41, the plurality of bolt through-holes 48 through which the spindle bolts 51 are inserted are formed so as to be arrayed in the circumferential direction Dc around the axis Ar. Accordingly, in the rotor disc 41, the plurality of axial flow passages 37 are also formed so as to be arrayed in the circumferential direction Dc around the axis Ar.
Next, a flow of air inside the compressor casing 10 will be described using
When air supplied from the intake opening Hi of the compressor casing 10 flows into the air compression flow passage 19, this air is gradually compressed while flowing through the air compression flow passage 19 toward the downstream side. Thus, the pressure inside the air compression flow passage 19 is higher on the downstream side. Accordingly, the pressure inside the radially outer flow passage 34 of the downstream-side cavity group 22d that communicates with the air compression flow passage 19 on the downstream side based on one blade row 81 is higher than the pressure inside the radially outer flow passage 34 of the upstream-side cavity group 22u that communicates with the air compression flow passage 19 on the upstream side based on this one blade row 81. Accordingly, the air inside the air compression flow passage 19 flows into the radially outer flow passage 34 of the downstream-side cavity group 22d. Thus, as described above, this radially outer flow passage 34 functions as the inlet flow passage 34d.
The air having flowed into the inlet flow passage 34d flows into the outer cavity 24 of the downstream-side cavity group 22d. This air flows into the intermediate cavity 25 through the radially intermediate flow passage 35 that is formed inside the torque pin 55. The air having flowed into the intermediate cavity 25 flows into the intermediate cavity 25 of the upstream-side cavity group 22u through the axial flow passage 37 that is formed by the gap 48s between the bolt through-hole 48 of the rotor disc 41 and the spindle bolt 51. This air flows into the outer cavity 24 of the upstream-side cavity group 22u through the radially intermediate flow passage 35 that is formed inside the torque pin 55. The air having flowed into the outer cavity 24 flows out into the air compression flow passage 19 from the radially outer flow passage 34 that provides communication between the outer cavity 24 of the upstream-side cavity group 22u and the air compression flow passage 19. Thus, as described above, this radially outer flow passage 34 functions as the outlet flow passage 34u.
Thus, in this embodiment, the pressure difference in the axial direction Da inside the air compression flow passage 19 is used as a driving force to generate a circulating flow of part of the air inside the air compression flow passage 19 flowing through the downstream-side cavity group 22d and the upstream-side cavity group 22u and returning into the air compression flow passage 19. This circulating flow promotes ventilation inside the cavities of the rotor shaft 21.
As shown in
The dimension in the radial direction Dr of the compressor rotor 20, particularly the rotor shaft 21, is large relative to the thickness of the compressor casing 10 in the radial direction Dr. Accordingly, the heat capacity of the compressor rotor 20 is larger than that of the compressor casing 10, and the thermal responsiveness of the compressor rotor 20 to changes in temperature of the air flowing through the air compression flow passage 19 is lower than that of the compressor casing 10. Thus, when the temperature of the air flowing through the air compression flow passage 19 changes, a change occurs in the tip clearance CC due to the difference in thermal responsiveness between the compressor rotor 20 and the compressor casing 10.
If there is a significant change in the tip clearance CC, it is necessary to provide a large steady-state clearance. The steady-state clearance refers to the tip clearance CC in a state where stable operation of the gas turbine continues and the temperatures of the compressor rotor 20 and the compressor casing 10 are continuously equal to each other. If this steady-state clearance is large, a larger amount of air passes between the radially outer end of the blade 82 and the inner circumferential surface of the compressor casing 10 during steady operation of the gas turbine. Thus, a large steady-state clearance not only degrades the compressor performance during steady operation of the gas turbine but also degrades the gas turbine performance.
In this embodiment, therefore, as described above, the air inside the air compression flow passage 19 is passed through the rotor shaft 21 to thereby enhance the thermal responsiveness of the compressor rotor 20 to changes in temperature of the air flowing through the air compression flow passage 19 and to reduce the change in the tip clearance CC. As the change in the tip clearance CC is thus reduced in this embodiment, the steady-state clearance can be reduced. Accordingly, in this embodiment, the compressor performance during steady operation of the gas turbine can be enhanced, and as a result, the gas turbine performance can be enhanced.
Next, the reason why the thermal responsiveness of the compressor rotor 20 is improved in this embodiment will be described using
As described above using
There is a difference in circumferential velocity (v2−V2) between the circumferential velocity v2 of the air having reached the end on the inner side in the radial direction Dr of the outer cavity 24 and a circumferential velocity V2 of an inlet opening 35di (see
When the air flows into the intermediate cavity 25, the air flows through the intermediate cavity 25 toward the inner side in the radial direction Dr while flowing in the circumferential direction Dc relative to the intermediate cavity 25. Inside the intermediate cavity 25, too, as the air flows through the intermediate cavity 25 toward the inner side in the radial direction Dr, the circumferential velocity of the air increases by the law of conservation of angular momentum. Thus, as the air flows through the intermediate cavity 25 toward the inner side in the radial direction Dr, the difference in circumferential velocity from the intermediate cavity 25 increases. The circumferential velocity of the air becomes v3 immediately before the air reaches one inlet opening 37i of the inlet openings 37i of the plurality of axial flow passages 37. The air flows into the axial flow passage 37 through the inlet opening 37i. The air flows through the axial flow passage 37 toward the upstream side, and flows into the intermediate cavity 25 of the upstream-side cavity group 22u. The air inside the axial flow passage 37 rotates integrally with the rotor shaft 21 around the axis Ar, so that the circumferential velocity of the air inside the axial flow passage 37 becomes roughly equal to a circumferential velocity V3 of the axial flow passage 37.
There is a difference in circumferential velocity (v3−V3) between the circumferential velocity v3 of the air immediately before reaching the inlet opening 37i (see
When the air flows into the intermediate cavity 25 of the upstream-side cavity group 22u, the air flows through the intermediate cavity 25 toward the outer side in the radial direction Dr while flowing in the circumferential direction Dc relative to the intermediate cavity 25. Inside the intermediate cavity 25, as the air flows through the intermediate cavity 25 toward the outer side in the radial direction Dr, the circumferential velocity of the air decreases by the law of conservation of angular momentum. Thus, as the air flows through the intermediate cavity 25 toward the outer side in the radial direction Dr, the difference in circumferential velocity from the intermediate cavity 25 increases. When the air reaches an end on the outer side in the radial direction Dr of the intermediate cavity 25, the circumferential velocity of the air becomes v4a. The air flows into one of the plurality of radially intermediate flow passages 35 that are open at the end. The air flows through the radially intermediate flow passage 35 toward the outer side in the radial direction Dr, and flows into the outer cavity 24 of the upstream-side cavity group 22u. The air inside the radially intermediate flow passage 35 rotates integrally with the rotor shaft 21 around the axis Ar, so that the circumferential velocity of the air inside the radially intermediate flow passage 35 becomes roughly equal to a circumferential velocity V4a of the radially intermediate flow passage 35.
There is a difference in circumferential velocity (v4a−V4a) between the circumferential velocity v4a of the air having reached the end on the outer side in the radial direction Dr of the intermediate cavity 25 and the circumferential velocity V4a of an inlet opening 35ui (see
When the air flows into the outer cavity 24, the air flows through the outer cavity 24 toward the outer side in the radial direction Dr while flowing in the circumferential direction Dc relative to the outer cavity 24. Inside the outer cavity 24, too, as the air flows through the outer cavity 24 toward the outer side in the radial direction Dr, the circumferential velocity of the air decreases by the law of conservation of angular momentum. Thus, as the air flows through the outer cavity 24 toward the outer side in the radial direction Dr, the difference in circumferential velocity from the outer cavity 24 increases.
This air returns into the air compression flow passage 19 through the outlet flow passage 34u.
Thus, in this embodiment, as described above, the pressure difference in the axial direction Da inside the air compression flow passage 19 is used as a driving force to generate a circulating flow of part of the air inside the air compression flow passage 19 flowing from the air compression flow passage 19 through the downstream-side cavity group 22d and the upstream-side cavity group 22u and returning to the air compression flow passage 19. Specifically, in this embodiment, part of the air inside the air compression flow passage 19 flows through the outer cavity 24 of the downstream-side cavity group 22d, the intermediate cavity 25 of the downstream-side cavity group 22d, the intermediate cavity 25 of the upstream-side cavity group 22u, and the outer cavity 24 of the upstream-side cavity group 22u in this order, and returns to the air compression flow passage 19. Thus, in this embodiment, as long as the rotor shaft 21 rotates, the inside each of the outer cavity 24 of the downstream-side cavity group 22d, the intermediate cavity 25 of the downstream-side cavity group 22d, the intermediate cavity 25 of the upstream-side cavity group 22u, and the outer cavity 24 of the upstream-side cavity group 22u can be ventilated with the circulating flow of the air flowing through these cavities.
Moreover, in this embodiment, there is a difference in circumferential velocity between the air and the cavities 23 inside the cavities 23 through which the air from the air compression flow passage 19 flows. Thus, the heat transfer coefficient of surfaces of the rotor discs 41 defining the cavities 23 can be increased.
In short, in this embodiment, the inside of each cavity 23 can be ventilated with the air flowing through the air compression flow passage 19. Moreover, in this embodiment, the heat transfer coefficient of wall surfaces of the rotor discs 41 can be increased. In this embodiment, therefore, the thermal responsiveness of the compressor rotor 20 to changes in temperature of the air flowing through the air compression flow passage 19 can be enhanced.
A circumferential flow passage that provides communication among the plurality of axial flow passages 37 formed so as to be arrayed in the circumferential direction Dc around the axis Ar may be formed in the rotor disc 41, at an intermediate position of the plurality of axial flow passages 37 in the axial direction Da. This circumferential flow passage is formed annularly around the axis Ar. If this circumferential flow passage is formed, the air having flowed into the inlet opening 37i of the axial flow passage 37 flows through the axial flow passage 37 toward the upstream side in the axial direction Da and reaches the circumferential flow passage. Then, this air flows through the circumferential flow passage in the circumferential direction, and flows into the intermediate cavity 25 on the upstream side from one of the axial flow passages 37. Adopting this form can produce the same enhancing effect on the thermal responsiveness of the compressor rotor 20 as in this embodiment.
Next, changes in circumferential velocity of air inside a rotor shaft in a comparative example of the above embodiment will be described using
As shown in
In this comparative example, the air inside the air compression flow passage 19 flows inside the rotor shaft 21 through the inlet flow passage 34d, the outer cavity 24 of the downstream-side cavity group 22d, the radially intermediate flow passage 35 of the downstream-side cavity group 22d, the common cavity 25x, the radially intermediate flow passage 35 of the upstream-side cavity group 22u, the outer cavity 24 of the upstream-side cavity group 22u, and the outlet flow passage 34u in this order, and returns to the air compression flow passage 19.
Changes in circumferential velocity of the air from inside the air compression flow passage 19 until immediately before the air reaches the common cavity 25x are the same as in the above embodiment. Thus, the circumferential velocity of the air immediately before reaching the common cavity 25x, i.e., the air at the end on the inner side in the radial direction Dr of the radially intermediate flow passage 35 of the downstream-side cavity group 22d, is roughly equal to the circumferential velocity of the rotor shaft 21 at that position.
The air having flowed from the radially intermediate flow passage 35 of the downstream-side cavity group 22d into the common cavity 25x flows into the radially intermediate flow passage 35 of the upstream-side cavity group 22u. An outlet opening of the radially intermediate flow passage 35 of the downstream-side cavity group 22d is formed at an edge on the outer side in the radial direction Dr of a downstream-side part of the common cavity 25x, and an inlet opening of the radially intermediate flow passage 35 of the upstream-side cavity group 22u is formed at an edge on the outer side in the radial direction Dr of an upstream-side part of the common cavity 25x. On the other hand, no opening of a flow passage is formed in a region of the common cavity 25x on the inner side in the radial direction Dr. Accordingly, the air having flowed from the radially intermediate flow passage 35 of the downstream-side cavity group 22d into the common cavity 25x flows through a region of the common cavity 25x on the outer side in the radial direction Dr toward the upstream side, and flows into the radially intermediate flow passage 35 of the upstream-side cavity group 22u. Thus, the air is stagnant in the region of the common cavity 25x on the inner side in the radial direction Dr, and there is almost no flow of the air from the air compression flow passage 19.
Subsequent changes in circumferential velocity of the air having flowed into the radially intermediate flow passage 35 of the upstream-side cavity group 22u are the same as in the above embodiment.
In this comparative example, although the air inside the air compression flow passage 19 flows into the common cavity 25x, as described above, this air flows through the region of the common cavity 25x on the outer side in the radial direction Dr toward the upstream side, while the air is stagnant in the region of the common cavity 25x on the inner side in the radial direction Dr. Thus, in this comparative example, the region of the common cavity 25x on the inner side in the radial direction Dr cannot be effectively ventilated. Moreover, in this comparative example, the air having flowed into the common cavity 25x does not flow much in the radial direction Dr inside the common cavity 25x, so that there is little difference in circumferential velocity between the air and the cavity 23 occurring as the air flows in the radial direction Dr.
In the above embodiment, therefore, the inlet opening 37i and the outlet opening 37o of the axial flow passage 37 that provides communication between the intermediate cavity 25 of the downstream-side cavity group 22d and the intermediate cavity 25 of the upstream-side cavity group 22u, which correspond to the common cavity 25x of this comparative example, are formed at the positions as described above. Specifically, in the above embodiment, as shown in
A second embodiment of the compressor will be described with reference to
In the compressor according to the first embodiment, the intermediate cavity 25 of the downstream-side cavity group 22d and the intermediate cavity 25 of the upstream-side cavity group 22u communicate with each other through the axial flow passages 37. In this embodiment, as shown in
In the rotor shaft 21 of this embodiment, a plurality of radially inner flow passages 38 are formed other than the radially outer flow passage 34 and the plurality of radially intermediate flow passages 35. The radially outer flow passage 34 provides communication between the outer cavity 24 and the air compression flow passage 19, The plurality of radially intermediate flow passages 35 provide communication between the outer cavity 24 and the intermediate cavity 25. The plurality of radially inner flow passages 38 provide communication between the intermediate cavity 25 and the inner cavity 26. As with the plurality of radially intermediate flow passages 35 of the first embodiment, the plurality of radially intermediate flow passages 35 of this embodiment are also separated from one another in the circumferential direction Dc. As with the plurality of radially intermediate flow passages 35 of the first embodiment, the plurality of radially inner flow passages 38 of this embodiment are also separated from one another in the circumferential direction Dc.
As shown in
As in the first embodiment, the upstream-side first arm 42u, the upstream-side first recess 43u, the upstream-side second arm 44u, the upstream-side second recess 45u, the upstream-side third arm 46u, and the upstream-side third recess 47u are formed on the upstream side of one rotor disc 41. As in the first embodiment, the plurality of upstream-side pin grooves 44up that are recessed toward the downstream side and provide communication between the upstream-side first recess 43u and the upstream-side second recess 45u are formed in the annular upstream-side second arm 44u. Moreover, a plurality of upstream-side flow passage grooves 46up that are recessed toward the downstream side and provide communication between the upstream-side second recess 45u and the upstream-side third recess 47u are formed in the annular upstream-side third arm 46u.
On the downstream side of one rotor disc 41, the downstream-side first arm 42d, the downstream-side first recess 43d, the downstream-side second arm 44d, the downstream-side second recess 45d, the downstream-side third arm 46d, and the downstream-side third recess 47d are formed. As in the first embodiment, the plurality of downstream-side pin grooves 44dp that are recessed toward the upstream side and provide communication between the downstream-side first recess 43d and the downstream-side second recess 45d are formed in the annular downstream-side second arm 44d. Moreover, a plurality of downstream-side flow passage grooves 46dp that are recessed toward the upstream side and provide communication between the downstream-side second recess 45d and the downstream-side third recess 47d are formed in the annular downstream-side third arm 46d.
In this embodiment, too, as in the first embodiment, the outer cavity 24 is defined by the downstream-side first recess 43d of one rotor disc 41, located on the upstream side, of two rotor discs 41 adjacent to each other in the axial direction Da, and by the upstream-side first recess 43u of the other rotor disc 41 located on the downstream side. The intermediate cavity 25 is defined by the downstream-side second recess 45d of one rotor disc 41, located on the upstream side, of two rotor discs 41 adjacent to each other in the axial direction Da, and by the upstream-side second recess 45u of the other rotor disc 41 located on the downstream side. The inner cavity 26 is defined by the downstream-side third recess 47d of one rotor disc 41, located on the upstream side, of two rotor discs 41 adjacent to each other in the axial direction Da, and by the upstream-side third recess 47u of the other rotor disc 41 located on the downstream side.
The radially outer flow passage 34 is defined by the downstream-side first arm 42d of one rotor disc 41, located on the upstream side, of two rotor discs 41 adjacent to each other in the axial direction Da, and by the upstream-side first arm 42u of the other rotor disc 41 located on the downstream side.
The pin holes in which the torque pins 55 are mounted are defined by the downstream-side pin grooves 44dp and the upstream-side pin grooves 44up. As in the first embodiment, the through-hole 56 constituting the radially intermediate flow passage 35 is formed inside the torque pin 55.
The radially outer flow passage 34 that provides communication between the air compression flow passage 19 and the outer cavity 24 of the downstream-side cavity group 22d of the cavity groups 22 making a set in the rotor shaft 21 constitutes the inlet flow passage 34d through which the air inside the air compression flow passage 19 flows into the outer cavity 24. The radially outer flow passage 34 that provides communication between the air compression flow passage 19 and the outer cavity 24 of the upstream-side cavity group 22u constitutes the outlet flow passage 34u through which the air inside the outer cavity 24 flows out into the air compression flow passage 19.
In the rotor disc 41 between the downstream-side cavity group 22d and the upstream-side cavity group 22u, the axial flow passages 39 are formed that provide communication between the inner cavity 26 of the downstream-side cavity group 22d and the inner cavity 26 of the upstream-side cavity group 22u. Thus, unlike the first embodiment, the axial flow passages 37 that provide communication between the intermediate cavity 25 of the downstream-side cavity group 22d and the intermediate cavity 25 of the upstream-side cavity group 22u are not formed in the rotor disc 41 between the downstream-side cavity group 22d and the upstream-side cavity group 22u.
An opening of the axial flow passage 39 to the inner cavity 26 of the downstream-side cavity group 22d constitutes an inlet opening 39i. An edge on the outer side in the radial direction Dr of the inlet opening 39i of the axial flow passage 39 is located on the inner side in the radial direction Dr of a center position in the radial direction Dr of the inner cavity 26 of the downstream-side cavity group 22d. An opening of the axial flow passage 39 to the inner cavity 26 of the upstream-side cavity group 22u constitutes an outlet opening 39o. An edge on the outer side in the radial direction Dr of the outlet opening 39o of the axial flow passage 39 is also located on the inner side in the radial direction Dr of a center position in the radial direction Dr of the inner cavity 26 of the upstream-side cavity group 22u. The center position in the radial direction Dr of the inner cavity 26 refers to a position corresponding to half the height in the radial direction Dr from a radially inner-side inner circumferential surface to a radially outer-side inner circumferential surface of inner circumferential surfaces defining the annular inner cavity 26.
Next, a flow of air inside the compressor casing 10 will be described using
In this embodiment, too, as in the first embodiment, the radially outer flow passage 34 that provides communication between the outer cavity 24 of the downstream-side cavity group 22d and the air compression flow passage 19 functions as the inlet flow passage 34d, and the air inside the air compression flow passage 19 flows into the inlet flow passage 34d.
In this embodiment, too, as in the above embodiment, the air inside the air compression flow passage 19 flows inside the rotor shaft 21 through the inlet flow passage 34d, the outer cavity 24 of the downstream-side cavity group 22d, the radially intermediate flow passage 35 of the downstream-side cavity group 22d, and the intermediate cavity 25 of the downstream-side cavity group 22d in this order. Thereafter, the air having flowed into the intermediate cavity 25 of the downstream-side cavity group 22d flows through the radially inner flow passage 38 of the downstream-side cavity group 22d and the inner cavity 26 of the downstream-side cavity group 22d in this order. The air having flowed into the inner cavity 26 of the downstream-side cavity group 22d flows into the inner cavity 26 of the upstream-side cavity group 22u through the axial flow passage 39. The air having flowed into the inner cavity 26 of the upstream-side cavity group 22u flows into the intermediate cavity 25 of the upstream-side cavity group 22u through the radially inner flow passage 38 of the upstream-side cavity group 22u. As in the above embodiment, the air having flowed into the intermediate cavity 25 of the upstream-side cavity group 22u flows through the radially intermediate flow passage 35 of the upstream-side cavity group 22u, the outer cavity 24 of the upstream-side cavity group 22u, and the outlet flow passage 34u in this order, and returns to the air compression flow passage 19.
Next, changes in circumferential velocity of the air inside the rotor shaft 21 in this embodiment will be described using
Changes in circumferential velocity of the air from inside the air compression flow passage 19 until the air reaches the intermediate cavity 25 of the downstream-side cavity group 22d are the same as in the above embodiment. When the air flows into the intermediate cavity 25 of the downstream-side cavity group 22d, the air flows through the intermediate cavity 25 toward the inner side in the radial direction Dr while flowing in the circumferential direction Dc relative to the intermediate cavity 25. Inside the intermediate cavity 25, as the air flows through the intermediate cavity 25 toward the inner side in the radial direction Dr, the circumferential velocity of the air increases by the law of conservation of angular momentum. Thus, as the air flows through the intermediate cavity 25 toward the inner side in the radial direction Dr, the difference in circumferential velocity from the intermediate cavity 25 increases. When the air reaches an end on the inner side in the radial direction Dr of the intermediate cavity 25, the air flows into one of the plurality of radially inner flow passages 38 opening at the edge. The air flows through the radially inner flow passage 38 toward the inner side in the radial direction Dr, and flows into the inner cavity 26 of the downstream-side cavity group 22d. The air inside the radially inner flow passage 38 rotates integrally with the rotor shaft 21 around the axis Ar, so that the circumferential velocity of the air inside the radially inner flow passage 38 becomes roughly equal to the circumferential velocity of the radially inner flow passage 38.
When the air flows into the inner cavity 26, the air flows through the inner cavity 26 toward the inner side in the radial direction Dr while flowing in the circumferential direction Dc relative to the inner cavity 26. Inside the inner cavity 26, too, as the air flows through the inner cavity 26 toward the inner side in the radial direction Dr, the circumferential velocity of the air increases by the law of conservation of angular momentum. Thus, as the air flows through the inner cavity 26 toward the inner side in the radial direction Dr, the difference in circumferential velocity from the inner cavity 26 increases. When the air reaches one opening of the openings of the plurality of axial flow passages 39, the air flows through this opening into the axial flow passage 39. The air flows through the axial flow passage 39 toward the upstream side, and flows into the inner cavity 26 of the upstream-side cavity group 22u. The air inside the axial flow passage 39 rotates integrally with the rotor shaft 21 around the axis Ar, so that the circumferential velocity of the air inside the axial flow passage 39 becomes roughly equal to the circumferential velocity of the axial flow passage 39.
When the air flows into the inner cavity 26 of the upstream-side cavity group 22u, the air flows through the inner cavity 26 toward the outer side in the radial direction Dr while flowing in the circumferential direction Dc relative to the inner cavity 26. Inside the inner cavity 26, as the air flows through the inner cavity 26 toward the outer side in the radial direction Dr, the circumferential velocity of the air decreases by the law of conservation of angular momentum. Thus, as the air flows through the inner cavity 26 toward the outer side in the radial direction Dr, the difference in circumferential velocity from the inner cavity 26 increases. When the air reaches an end on the outer side in the radial direction Dr of the inner cavity 26, the air flows into one of the plurality of radially inner flow passages 38 opening at the end.
The air flows through the radially inner flow passage 38 toward the outer side in the radial direction Dr, and flows into the intermediate cavity 25 of the upstream-side cavity group 22u. The air inside the radially inner flow passage 38 rotates integrally with the rotor shaft 21 around the axis Ar, so that the circumferential velocity of the air inside the radially inner flow passage 38 becomes roughly equal to the circumferential velocity of the radially inner flow passage 38.
Subsequent changes in circumferential velocity of the air until the air returns to the air compression flow passage 19 after flowing through the intermediate cavity 25, the radially intermediate flow passage 35, the outer cavity 24, and the outlet flow passage 34u of the upstream-side cavity group 22u are the same as in the above embodiment.
As has been described above, in this embodiment, as in the first embodiment, the pressure difference in the axial direction Da inside the air compression flow passage 19 is used as a driving force to generate a circulating flow of part of the air inside the air compression flow passage 19 flowing from the air compression flow passage 19 through the downstream-side cavity group 22d and the upstream-side cavity group 22u and returning to the air compression flow passage 19. Specifically, in this embodiment, part of the air inside the air compression flow passage 19 flows through the outer cavity 24 of the downstream-side cavity group 22d, the intermediate cavity 25 of the downstream-side cavity group 22d, the inner cavity 26 of the downstream-side cavity group 22d, the inner cavity 26 of the upstream-side cavity group 22u, the intermediate cavity 25 of the upstream-side cavity group 22u, and the outer cavity 24 of the upstream-side cavity group 22u in this order, and returns into the air compression flow passage 19. Thus, in this embodiment, as long as the rotor shaft 21 rotates, the inside each of the cavities of the downstream-side cavity group 22d and the cavities of the upstream-side cavity group 22u can be ventilated with the circulating flow of the air flowing through these cavities. In particular, in this embodiment, as the circulating flow also passes through the inside of the inner cavity 26 of the downstream-side cavity group 22d and the inner cavity 26 of the upstream-side cavity group 22u, the inside of these cavities can also be ventilated.
In this embodiment, too, there is a difference in circumferential velocity between the air and the cavities 23 inside the cavities 23 through which the air from the air compression flow passage 19 flows. Thus, the heat transfer coefficient of the surfaces of the rotor discs 41 defining the cavities 23 can be increased.
In this embodiment, therefore, the thermal responsiveness of the compressor rotor 20 to changes in temperature of the air flowing through the air compression flow passage 19 can be enhanced more than in the first embodiment.
A first modified example of the second embodiment will be described with reference to
In the first and second embodiments, if there is a large difference in circumferential velocity between the air and the radial flow passage or the axial flow passage when the air flows from one of the cavities 23 into this flow passage, the air cannot flow smoothly into this flow passage, which results in a pressure loss of the flow of air.
In this modified example, therefore, the pressure loss of the flow of air is reduced by allowing the air to flow smoothly into the flow passage even when there is a difference in circumferential velocity between the air and the flow passage. For this purpose, in this modified example, an inlet-side part of the flow passage including the inlet opening is formed so that, as the inlet-side part extends toward the inlet opening, the inlet-side part is directed toward the opposite side from a direction, relative to the inlet opening, of the air flowing into the inlet opening in the circumferential direction Dc.
Specifically, as shown in
As described using
Thus, as shown in
As described above, the flow velocity V1 of the air immediately after flowing into the outer cavity 24 through the inlet flow passage 34d varies according to the structure of the inlet flow passage 34d, the operation conditions of the compressor, etc. Thus, the direction of the relative circumferential velocity vr2 (=v2−V2) of the air relative to the inlet opening 35di may be toward the rotation side of the rotor shaft 21. In this case, it is desirable that the inlet-side part including the inlet opening 35di of the radially intermediate flow passage 35d is inclined toward the counter rotation side (counter rotation direction side) opposite from the rotation side (rotation direction side) at a predetermined angle.
In this embodiment, the radially intermediate flow passage 35d is formed inside a torque pin 55d. Therefore, as shown in
As shown in
As described above using
Thus, as shown in
As described above using
Thus, as shown in
As shown in
As described above using
Thus, as shown in
As described above using
Thus, as shown in
In this embodiment, the radially intermediate flow passage 35u is formed inside a torque pin 55u. Accordingly, as shown in
Although this modified example is a first modified example of the second embodiment, the same modifications may be made to the first embodiment.
Next, a second modified example of the second embodiment will be described with reference to
This modified example is an example in which an outlet part of the radial flow passage or the axial flow passage is inclined toward the rotation direction side of the rotor shaft 21 or toward the counter rotation side opposite from the rotation direction side. In this example, the outlet parts of the flow passages, namely, the radial flow passages of the downstream-side cavity group 22d, the radial flow passages of the upstream-side cavity group 22u, and the axial flow passage, shown in the first modified example are open in the direction coinciding with the radial direction Dr or the axial direction Da, without being inclined relative to the rotation direction. However, these outlet parts may be inclined toward the rotation direction side or toward the opposite side from the rotation direction side (counter rotation side).
As shown in
By contrast, as shown in
As shown in
By contrast, as shown in
As shown in
By contrast, as shown in
As shown in
As has been described above, the effect produced by inclining the outlet part of the radial flow passage in either direction relative to the rotation direction (toward the rotation direction side or the counter rotation direction side) differs between the upstream-side cavity group 22u and the downstream-side cavity group 22d. Specifically, in the case where the outlet-side part 35dop of the radially intermediate flow passage 35d or the outlet-side part 38dop of the radially inner flow passage 38d of the downstream-side cavity group 22d is inclined toward the rotation direction side, the difference in circumferential velocity between the air and the intermediate cavity 25 or the inner cavity 26 increases. Thus, in this case, heat transfer is promoted between the air and the intermediate cavity 25 or the inner cavity 26, so that the thermal responsiveness of the intermediate cavity 25 or the inner cavity 26 can be improved.
In the case where the outlet-side part 35dop of the radially intermediate flow passage 35d or the outlet-side part 38dop of the radially inner flow passage 38d of the downstream-side cavity group 22d is inclined toward the counter rotation side, the difference in circumferential velocity between the air and the intermediate cavity 25 or the inner cavity 26 decreases. Thus, in this case, the pressure loss occurring when the air flows from the intermediate cavity 25 into the inlet opening 38di of the radially inner flow passage 38d or from the inner cavity 26 into the inlet opening 39i of the axial flow passage 39 can be significantly reduced.
By contrast, in the case where the outlet-side part 38uop of the radially inner flow passage 38u of the upstream-side cavity group 22u or the outlet-side part 39op of the axial flow passage 39 is inclined toward the rotation direction side, the difference in circumferential velocity between the air and the intermediate cavity 25 or between the air and the inner cavity 26 decreases. Thus, in this case, the pressure loss occurring when the air flows from the intermediate cavity 25 into the inlet opening 35ui of the radially intermediate flow passage 35u or from the inner cavity 26 into the inlet opening 38ui of the radially inner flow passage 38u can be significantly reduced.
In the case where the outlet-side part 35uop of the radially intermediate flow passage 35u of the upstream-side cavity group 22u, the outlet-side part 38uop of the radially inner flow passage 38u of the upstream-side cavity group 22u, or the outlet-side part 39op of the axial flow passage 39 is inclined toward the counter rotation side, the difference in circumferential velocity between the air and the outer cavity 24, between the air and the intermediate cavity 25, or between the air and the inner cavity 26 increases. Thus, in this case, heat transfer is promoted between the air and the outer cavity 24, the intermediate cavity 25, or the inner cavity 26, so that the thermal responsiveness of the outer cavity 24, the intermediate cavity 25, or the inner cavity 26 can be improved.
Thus, the combination of the direction and the angle of inclination, relative to the rotation direction, of the inlet-side part or the outlet-side part of the radial flow passages (the radially intermediate flow passages 35d, 35u and the radially inner flow passages 38d, 38u) of the upstream-side cavity group 22u and the downstream-side cavity group 22d and those of the axial flow passages 37, 39 can be appropriately selected, with the performance and the structure of the compressor taken into account, so that the highest thermal responsiveness can be achieved.
Although this modified example is a second modified example of the second embodiment, the same modifications may be made to the first embodiment. In addition, the first modified example and the second modified example may be appropriately combined.
According to
Although this modified example is a third modified example of the second embodiment, the same modifications may be made to the first embodiment. In addition, the first modified example, the second modified example, and the third modified example may be appropriately combined.
Other modified examples of the first embodiment will be described with reference to
In the first and second embodiments, two cavity groups 22 adjacent to each other in the axial direction Da make a set. However, three or more cavity groups 22 adjacent to one another in the axial direction Da may make a set.
For example, in the case where three cavity groups 22 adjacent to one another in the axial direction Da make a set, as shown in
In this case, the intermediate cavities (axial communication cavities) 25 of a first downstream-side cavity group 22d1, located on the downstream side, and a second downstream-side cavity group 22d2, located on the upstream side, of the two downstream-side cavity groups 22d communicate with each other through the axial flow passages 37, and the intermediate cavities (axial communication cavities) 25 of the second downstream-side cavity group 22d2 and the upstream-side cavity group 22u communicate with each other through the axial flow passages 37.
In the case where four cavity groups 22 adjacent to one another in the axial direction Da make a set, of the four cavity groups 22 composing this set, the cavity group 22 located farthest on the upstream side may constitute the upstream-side cavity group, and the other three cavity groups 22 may constitute the downstream-side cavity groups. Alternatively, of the four cavity groups 22 composing this set, two cavity groups 22 located on the upstream side may constitute the upstream-side cavity groups, and the other two cavity groups 22 may constitute the downstream-side cavity groups.
In the case where three or more cavity groups 22 adjacent to one another in the axial direction Da make a set as has been described above, for example, if the air does not flow toward the upstream side through the axial flow passage 37 that provides communication between the axial communication cavities of the cavity group 22 located farthest on the downstream side and the cavity group 22 adjacent thereto in the axial direction Da, the air from the air compression flow passage 19 does not return to the air compression flow passage 19. It is therefore necessary to appropriately determine the flow passage resistance in the flow passages including the axial flow passage 37 so that the air flows through the axial flow passage 37 toward the upstream side.
Although this modified example is a modified example of the first embodiment, the same modifications may be made to the second embodiment and the modified examples thereof.
In all the above embodiments and modified examples, the present invention is applied to the cavity groups 22 from the first cavity group 22 located farthest on the downstream side inside the rotor shaft 21 to the sixth cavity group 22 located on the upstream side. However, the present invention may instead be applied to the cavity groups 22 from the first cavity group 22 located farthest on the downstream side inside the rotor shaft 21 to, for example, an eighth cavity group 22 on the upstream side, or the present invention may be applied to all the cavity groups 22 located on the upstream side from the first cavity group 22 located farthest on the downstream side. Alternatively, for example, the present invention may be applied to the cavity groups 22 from the first cavity group 22 located farthest on the downstream side inside the rotor shaft 21 to the fourth cavity group 22 on the upstream side, or the present invention may be applied to the cavity groups 22 from the first cavity group 22 located farthest on the downstream side inside the rotor shaft 21 to the second cavity group 22 on the upstream side.
In short, the present invention can be applied to a plurality of cavity groups 22 that are adjacent to one another in the axial direction Da and include the first cavity group 22 located farthest on the downstream side inside the rotor shaft 21. Thus, the cavity groups 22 to which the present invention is applied include the first cavity group 22 farthest on the downstream side inside the rotor shaft 21. This is because, in the air compression flow passage 19, the pressure at the position in the axial direction Da at which the first cavity group 22 is present is higher than the pressure at the other positions, and changes in temperature at that position inside the rotor shaft 21 are larger than at the other positions.
Although all the above embodiments and modified examples are the compressor of the gas turbine, the present invention is not limited thereto. Thus, the gas flowing into the compressor in the present invention is not limited to air.
In all the above embodiments and modified examples, part of the air in the compression process flowing through the air compression flow passage 19 of the compressor 1 is introduced into the rotor shaft 21, and the inside of the cavities of the rotor shaft 21 is ventilated with this air. Instead of this method, another method is also conceivable in which outlet air that flows out from the air compression flow passage 19 of the compressor 1 and is present inside the gas turbine casing 9 is introduced into the rotor shaft 21, and the inside of the cavities of the rotor shaft 21 is ventilated with this air. In this method, however, the air of which the pressure has risen to a target pressure and which has flowed out of the air compression flow passage 19 is used to ventilate the inside of the cavities of the rotor shaft 21, a larger amount of energy is consumed to increase the pressure of the air used for ventilation than in the above embodiments and modified examples. Moreover, since the temperature of the air used for ventilation is higher than the temperature of the part of the rotor shaft 21 where the vane rows 11 are provided, the ventilation effect is smaller than in the above embodiments and modified examples. Therefore, again, it is preferable that part of the air in the compression process flowing through the air compression flow passage 19 of the compressor 1 be introduced into the rotor shaft 21, and that the inside of the cavities of the rotor shaft 21 be ventilated with this air, as in the above embodiments and modified examples.
According to one aspect of the present invention, the thermal responsiveness of the rotor shaft to changes in temperature of gas flowing through the gas compression flow passage can be further enhanced.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2015-090289 | Apr 2015 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2016/062236 | 4/18/2016 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2016/175072 | 11/3/2016 | WO | A |
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| 6053701 | Ichiryu et al. | Apr 2000 | A |
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| 6435831 | Ichiryu | Aug 2002 | B1 |
| 20120183398 | Are et al. | Jul 2012 | A1 |
| 20130259685 | Are et al. | Oct 2013 | A1 |
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| International Search Report dated Jul. 12, 2016 in International Application No. PCT/JP2016/062236, with English translation. |
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| Number | Date | Country | |
|---|---|---|---|
| 20180051710 A1 | Feb 2018 | US |
