Patent Grant
9719354
The present invention relates to a gas turbine that, for example, burns a high temperature and pressure compressed air with supplying fuel to the air so as to obtain rotary power by supplying the generated combustion gas to the turbine.
A gas turbine includes a compressor, a combustor and a turbine. The compressor compresses the air from an air inlet so that the air becomes a high temperature and pressure compressed air. The combustor burns the compressed air with supplying fuel. The high temperature and pressure combustion gas drives the turbine and also drives an electricity generator connected to the turbine. In such a case, the turbine includes a plurality of turbine vanes and turbine blades that are alternately provided in a cylinder. Driving the turbine blades with the combustion gas rotates and drives an output shaft to which the electricity generator is connected. The energy of the combustion gas (flue gas) after driving the turbine is gradually converted into pressure with a flue gas diffuser without loss and is released into the air.
The flue gas diffuser is provided at the turbine in the gas turbine having such a configuration so as to extend the flow passage area from the exit of the turbine, namely, the entrance of the diffuser in the direction in which the flue gas fluidizes. The flue gas diffuser decelerates the flue gas after the power is recovered in the turbine and can restore the pressure.
A gas turbine having such a flue gas diffuser is, for example, described in Patent Literature 1.
Patent Literature 1: Japanese Laid-open Patent Publication No. 2009-203871
By the way, the amount of restoration of the pressure increased by a deceleration of the flue gas in the flue gas diffuser improves the efficiency of the turbine so that the performance of the gas turbine can be improved. Making the flow passage area at the exit larger than the flow passage area at the entrance facilitates an increase in the amount of restoration of the pressure in the flue gas diffuser. However, when the flow passage area at the exit is drastically larger than the flow passage area at the entrance in the flue gas diffuser, the flow of the flue gas is separated near the wall surface on outer circumference side or near the wall surface on the center side. This reduces the amount of restoration of the pressure. On the other hand, preventing the flow passage area at the exit from being drastically larger than the flow passage area at the entrance in the flue gas diffuser elongates the length in the longitudinal direction of the flue gas diffuser (the direction in which the flue gas fluidizes). This causes an increase in the size of the flue gas diffuser.
To solve the problem, an objective of the present invention is to provide a gas turbine capable of improving the performance with improving the efficiency of the turbine by efficiently restoring the pressure of the flue gas.
According to an aspect of the present invention in order to solve the problems, there is provided a gas turbine for burning air compressed in a compressor with supplying fuel in a combustor so as to obtain rotary power by supplying generated combustion gas to a turbine, wherein the turbine turbine vane elements and turbine blade elements that are alternately positioned in a direction in which the combustion gas fluidizes, the turbine vane elements and turbine blade elements being arranged in a turbine cylinder having a cylindrical shape, and a flue gas diffuser having a cylindrical shape and connected to a rear portion of the turbine cylinder, the turbine vane element includes a plurality of turbine vanes positioned at equal intervals in a circumference direction and the turbine blade element includes a plurality of turbine blades fixed at equal intervals in a circumference direction, and the turbine vanes or the turbine blades have a throat width on a longitudinal end side made larger than a throat width on a longitudinally intermediate portion side.
Thus, setting the throat width on an end side of the turbine vanes or the turbine blades larger than the throat width on the intermediate portion side makes the outflow angle on the end side smaller than the outflow angle at the intermediate portion. This appropriately controls the flow of the flue gas flowing in the flue gas diffuser so that the pressure of the flue gas can efficiently be restored. This improves the efficiency of the turbine so that the performance can be improved.
According to another aspect of the present invention, there is provided the gas turbine, wherein the turbine vanes or the turbine blades have throat widths on both longitudinal end sides made larger than a throat width on a longitudinally intermediate portion side.
This can appropriately control the flow of the flue gas flowing from both longitudinal end sides of the turbine vanes or the turbine blades to the flue gas diffuser so that the amount of restoration of the pressure can appropriately be increased therein.
According to still another aspect of the present invention, there is provided the gas turbine, wherein the turbine blades have a throat width on a base end side fixed on a turbine shaft and a throat width on a tip side made larger than a throat width on an intermediate portion side between the base end side and the tip side, and the throat width on a tip side is made larger than the throat width on a base end side.
Thus, setting the throat width on the end side of the turbine blades larger than the throat width on the intermediate portion side makes the outflow angle on the end side smaller than the outflow angle on the intermediate portion side. This decreases the amount of the power obtained from the combustion gas on the end side and increases the amount of the power obtained from the combustion gas on the intermediate portion side. As a result, the total pressure of the combustion gas becomes higher at the exit on the end side of the turbine blades than at the exit on the intermediate portion. Thus, the flue gas is not likely to be separated near the wall surface of the flue gas diffuser. This increases the amount of restoration of the pressure therein. Efficiently restoring the pressure of the flue gas improves the efficiency of the turbine so that the performance can be improved.
According to still another aspect of the present invention, there is provided the gas turbine, wherein the turbine vanes have a throat width on a base end side fixed on the turbine shaft and a throat width on a tip side made larger than a throat width on an intermediate portion side between the base end side and the tip side, and the throat width on the base end side is almost the same as the throat width on the tip side.
Thus, setting the throat width on the end side of the turbine vanes larger than the throat width on the intermediate portion side makes the outflow angle on the end side smaller than the outflow angle on the intermediate portion side. Thus, the inflow angle on the end side of the turbine blades positioned on the lower flow side of the turbine vanes decreases. This makes the turning angle of the combustion gas on the end side of the turbine blades smaller than on the intermediate portion side. Thus, the amount of the power obtained from the combustion gas decreases on the end side and the amount of the power obtained from the combustion gas increases on the intermediate portion side. As a result, the total pressure of the combustion gas becomes higher at the exit on the end side of the turbine blades than at the exit on the intermediate portion side. Thus, the flue gas is not likely to be separated near the wall surface of the flue gas diffuser so that the amount of restoration of the pressure increases therein. Efficiently restoring the pressure of the flue gas improves the efficiency of the turbine so that the performance can be improved.
According to still another aspect of the present invention, there is provided the gas turbine, wherein the turbine blades on a last stage turbine blade element have a throat width on a longitudinal end made larger than a throat width on a longitudinally intermediate portion side.
Thus, setting the total pressure of the flue gas flowing from the last stage turbine blade element to the flue gas diffuser at an appropriate value in a radial direction can increase the amount of restoration of the pressure in the flue gas diffuser.
According to still another aspect of the present invention, there is provided the gas turbine, wherein the turbine vanes on a last stage turbine vane element have a throat width on a longitudinal end made larger than a throat width on a longitudinally intermediate portion side.
Thus, setting the total pressure of the flue gas flowing from the last stage turbine vane element to the flue gas diffuser through the last stage turbine blade element at an appropriate value in a radial direction can increase the amount of restoration of the pressure in the flue gas diffuser.
The gas turbine of the present invention has a throat width on an end side in the longitudinal direction of the turbine vanes or the turbine blades made larger than the throat width on the longitudinally intermediate portion side. This makes the outflow angle on the end side smaller than the outflow angle at the intermediate portion. This can appropriately control the flow of the flue gas flowing in the flue gas diffuser. Thus, efficiently restoring the pressure of the flue gas improves the efficiency of the turbine so that the performance can be improved.
Hereinafter, the preferred embodiments of the gas turbine according to the present invention will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the embodiments and includes a combination of the embodiments when there is a plurality of embodiments.
As illustrated in
The compressor 11 includes an air inlet 21, a plurality of compressor vane elements 23 and compressor blade elements 24 in a compressor cylinder 22 and a extraction room 25 at the outside of the compressor cylinder 22. The air inlet 21 takes in the air. The compressor vane elements 23 and compressor blade elements 24 are alternately provided in a longitudinal direction (the axial direction of a rotor 32 to be described below). The combustor 12 is capable of burning the air compressed in the compressor 11 by supplying fuel to the compressed air and igniting it. The turbine 13 includes a plurality of turbine vane elements 27 and turbine blade elements 28 that are alternately provided in a turbine cylinder 26 in the longitudinal direction (the axial direction of a rotor 32 to be described below). A flue gas room 30 is provided on the lower stream side of the turbine cylinder 26 trough a flue gas cylinder 29. The flue gas room 30 includes a flue gas diffuser 31 connected to the turbine 13.
A rotor (turbine shaft) 32 is positioned so as to penetrate through the centers of the compressor 11, the combustor 12, the turbine 13, and the flue gas room 30. An end of the rotor 32 that is on the compressor 11 side is rotatably supported with a bearing 33. The other end of the rotor 32 that is on the flue gas room 30 side is rotatably supported with a bearing 34. A plurality of disks that each is equipped with the compressor blade elements 24 and that are arranged in a row is fixed on the rotor 32 in the compressor 11. A plurality of disks that each is equipped with the turbine blade elements 28 and that are arranged in a row is fixed on the rotor 32 in the turbine 13. The driving shaft of the electricity generator (not illustrated in the drawings) is connected to the end of the rotor 32 on the compressor 11 side.
In the gas turbine, the compressor cylinder 22 of the compressor 11 is supported with a leg portion 35. The turbine cylinder 26 of the turbine 13 is supported with a leg portion 36. The flue gas room 30 is supported with a leg portion 37.
Thus, the air taken in from the air inlet 21 of the compressor 11 is compressed with passing through the compressor vane elements 23 and the compressor blade elements 24 so as to become a high temperature and pressure compressed air. The compressed air is supplied with predetermined fuel and is burnt in the combustor 12. The high temperature and pressure combustion gas that is working fluid generated in the combustor 12 drives and rotates the rotor 32 by passing through the turbine vane elements 27 and the turbine blade elements 28 included in the turbine 13 such that the electricity generator connected to the rotor 32 is driven. On the other hand, the energy of the flue gas (combustion gas) is released into the air after being converted into pressure and decelerated with the flue gas diffuser 31 of the flue gas room 30.
In the turbine 13 as illustrated in
The turbine cylinder 26 and the flue gas cylinder 29 are connected to each other with a plurality of connecting bolts 41. The flue gas cylinder 29 and the flue gas room 30 are connected to each other with a plurality of flue gas room supports 42 and 43 capable of absorbing thermal expansion. The flue gas room supports 42 and 43 have a rectangular shape and extend along the axial direction of the turbine 13 as being provided at predetermined intervals in the circumferential direction. The deformation of the flue gas room supports 42 and 43 can absorb thermal expansion when the thermal expansion has occurred between the flue gas cylinder 29 and the flue gas room 30 because of the difference of the temperatures. The thermal expansion tends to occur during a period of transition, for example, during the activation of the turbine 13 or during a high-loaded state. A gas seal 44 is provided between the flue gas cylinder 29 and the flue gas room 30 as being positioned between each of the flue gas room supports 42 and 43.
The flue gas diffuser 31 that includes the flue gas room 30 therein and has a cylindrical shape is positioned in flue gas cylinder 29. The flue gas diffuser 31 includes an external diffuser 45 and an internal diffuser 46 that are formed into a cylindrical shape with being connected to each other with a plurality of strut shields 47. The strut shields 47 have a hollow structure, for example, a cylindrical shape or an elliptically cylindrical shape and are provided at equal intervals in the circumferential direction of the flue gas diffuser 31. Note that the flue gas room supports 42 and 43, and the gas seal 44 are connected to the external diffuser 45 of the flue gas diffuser 31 of which end is formed into the flue gas room 30.
A strut 48 is provided in the strut shield 47. An end of the strut 48 penetrates through the internal diffuser 46 and is connected to a bearing box 49 housing the bearing 34 such that the rotor 32 is rotatably supported by the bearing 34. The other end of the strut 48 penetrates through the external diffuser 45 and is fixed at the flue gas cylinder 29. Note that the space in the strut shield 47 is communicated with the space in the flue gas diffuser 31 (the internal diffuser 46) and the space between the flue gas cylinder 29 and the flue gas diffuser 31 (the external diffuser 45) so that cooling air can be supplied into the spaces from the outside.
The turbine vane elements 27 and the turbine blade elements 28 are alternately provided in the turbine cylinder 26 and have almost the same blade ring structures and vane ring structure at the stages. In that case, each of the turbine vane elements 27 includes a plurality of turbine vanes 27a positioned in equal intervals in the circumferential direction. An internal shroud 27b is fixed at the base end on the rotor 32 side and an external shroud 27c is fixed at the tip on the turbine cylinder 26 side. Similarly, each of the turbine blade elements 28 includes turbine blades 28a positioned in equal intervals in the circumferential direction. The base end of each turbine blade 28a is fixed at a rotor disk 28b fixed at the rotor 32 and the tip extends toward the turbine cylinder 26 side. Last stage turbine blades 28a are positioned on the lower stream side of last stage turbine vanes 27a.
In that case, a last stage vane ring structure in the turbine cylinder 26 includes a turbine cylinder body 51 having a cylindrical shape, a vane ring 52 provided in the turbine cylinder body 51 and having a cylindrical shape, a split ring 53 positioned laterally to the last stage turbine blades 28a and having a cylindrical shape, and heat barrier rings 54, 55, and 56 connecting the split ring 53, the vane ring 52, and the external shroud 27c of the last stage turbine vane 27a.
The blade ring structure and the vane ring structure are formed at each stage in the turbine 13 as described above. Thus, the internal shroud 27c, the split ring 53, and the like included in the turbine cylinder 26 are formed into a combustion gas passage A. The front portion of the flue gas diffuser 31 enters the rear insides of the turbine cylinder 26 and the flue gas cylinder 29 as leaving a predetermined clearance in the radial direction and is connected to a seal device 57 so as to be formed into a flue gas passage B. The combustion gas passage A and the flue gas passage B are coupled to each other.
In the turbine 13 of the first embodiment having such a structure, the turbine blades (last stage turbine blades) 28a have a large throat width at a longitudinal end than a throat width at the longitudinally intermediate portion as illustrated in
Specifically,
The throat widths w1 and w3 on the tip side and on the base end side of the turbine blades 28a are larger than the throat with w2 on the intermediate portion side. The throat with w3 on the base end side is larger than the throat with w1 on the tip side.
Note that the throat is a minimum area portion between the back surface and the front surface of the turbine blades 28a that are adjacent to each other in a circumferential direction on the lower stream side in the direction in which the combustion gas fluidizes. The throat widths w are widths of the throat portions. Further, an outflow direction is perpendicular to the width direction of the throat portion. The outflow angles θ are angles of the outflow directions to the axial core direction of the rotor 32.
Thus, as illustrated in
Thus, the turbine blades 28a have small outflow angles on the tip side and on the base end side, in other word, have large throat widths on both of the sides so that the amount of the power obtained from the combustion gas decreases. On the other hand, the turbine blades 28a have a large outflow angle on the intermediate portion side, namely, have a small throat width so that the amount of the power obtained from the combustion gas increases. Thus, as illustrated in
As described above, the gas turbine in the first embodiment is configured to burn the air compressed in the compressor 11 with supplying fuel in the combustor 12 so as to obtain rotary power by supplying the generated combustion gas to the turbine 13. The turbine vane elements 27 and the turbine blade elements 28 are alternately positioned in the cylindrical turbine cylinder 26 in the direction in which the combustion gas fluidizes. The cylindrical flue gas diffuser 31 is connected to the rear portion of the turbine cylinder 26 so as to be formed into the turbine 13. The turbine blades 28a are positioned at equal intervals in the circumferential direction so as to be formed into the turbine blade elements 28. The turbine blades 28a have a throat width on a longitudinal end side made larger than the throat width on the longitudinally intermediate portion side.
Thus, setting the throat width on the end side of the turbine blades 28a larger than the throat width on the intermediate portion side makes the outflow angle on the end side smaller than the outflow angle on the intermediate portion side. This decreases the amount of the power obtained from the combustion gas on the end side and increases the amount of the power obtained from the combustion gas on the intermediate portion side. As a result, the total pressure of the combustion gas becomes higher at the exit on the end side of the turbine blades 28a than at the exit on the intermediate portion. Thus, the flue gas is not likely to be separated near the wall surface of the flue gas diffuser 31 so that the amount of restoration of the pressure is increased therein. The efficient restoration of the pressure of the flue gas improves the efficiency of the turbine. This can improve the performance.
In the gas turbine in the first embodiment, the throat widths on both longitudinal end sides of the turbine blades 28a are larger than the throat width on the longitudinally intermediate portion side. Thus, the flow of the flue gas from both longitudinal end sides of the turbine blades 28a to the flue gas diffuser 31 can appropriately be controlled so that the amount of restoration of the pressure can appropriately be increased therein.
In the gas turbine in the first embodiment, the throat width on an end side of the turbine blades 28a on the last stage turbine blade element 28 are made larger than the throat width on the longitudinally intermediate portion side. Thus, the total pressure of the flue gas flowing from the last stage turbine blade element 28 to the flue gas diffuser 31 can be set at an appropriate value in the radial direction. This can increase the amount of restoration of the pressure in the flue gas diffuser 31.
Note that, although both of the throat widths on the longitudinal tip side and base end side of the turbine blades 28a are made larger than the throat width on the intermediate portion side in the first embodiment, only the throat width on the longitudinal tip side of the turbine blades 28a or the throat width on the base end side can be made larger than the throat width on the intermediate portion side.
In the turbine of the gas turbine in the second embodiment, the turbine vanes (last stage turbine vanes) 27a have a throat width on a longitudinal end side made larger than the throat width on the longitudinally intermediate portion side as illustrated in
Specifically,
The throat widths w11 and w13 on the tip side and on the base end side of the turbine vanes 27a are larger than the throat width w12 on the intermediate portion side. The throat width w11 on the tip side has almost the same size as the throat width w13 on the base end side.
Note that the throat is a minimum area portion between the back surface and the front surface of the turbine vanes 27a that are adjacent to each other in the circumferential direction on the lower stream side in the direction in which the combustion gas fluidizes. The throat widths w are widths of the throat portions. Further, an outflow direction is perpendicular to the width direction of the throat portion. The outflow angles θ are angles of the outflow directions to the axial core direction of the rotor 32.
Thus, as illustrated in
Thus, the turbine vanes 27a have small outflow angles on the tip side and on the base end side and thus the inflow angles on the tip side and on the base end side of the turbine blades 28a positioned on the lower stream become small. This reduces the turning angles on the tip side and on the base end side of the turbine blades 28a. Thus, the amount of the power obtained from the combustion gas decreases. On the other hand, the turbine vanes 27a have a large outflow angle on the intermediate portion side and thus the inflow angle on the intermediate portion side of the turbine blades 28a positioned on the lower stream become large. This increases the turning angle on the intermediate portion side of the turbine blades 28a. Thus, the amount of the power obtained from the combustion gas increases. Thus, the total pressure of the combustion gas (flue gas) conventionally stays constant at the turbine blade exit from the tip side to the base end side of the turbine blades, namely, the entrance of the flue gas diffuser as represented with the alternate long and short dash line illustrated in
In the gas turbine in the second embodiment as described above, the turbine vanes 27a are positioned at equal intervals in the circumferential direction so as to be formed into the turbine vane element 27. The throat width on the base end side positioned on the rotor 32 side of the turbine vanes 27a and the throat width on the tip side are made larger than the throat width on the intermediate portion side between the base end side and the tip side. The throat width on the base end side has almost the same size as the throat width on the tip side.
Thus, setting the throat width on an end side of the turbine vanes 27a larger than the throat width on the intermediate portion side makes the outflow angle on the end side smaller than the outflow angle on the intermediate portion side. The inflow angle and the turning angle on the end side of the turbine blades 28a positioned on the lower flow side decrease. Thus, the amount of the power obtained from the combustion gas decreases on the end side and the amount of the power obtained from the combustion gas increases on the intermediate portion side. As a result, the total pressure of the combustion gas becomes higher at the exit on the end side of the turbine blades 28a than at the exit on the intermediate portion side. Thus, the flue gas is not likely to be separated near the wall surface of the flue gas diffuser 31 so that the amount of restoration of the pressure increases therein. The efficient restoration of the pressure of the flue gas improves the efficiency of the turbine. This can improve the performance.
In the gas turbine in the second embodiment, the throat width on the longitudinal end side of the turbine vanes 27a on the last stage turbine vane element 27 are made larger than the throat width on the longitudinally intermediate portion side. Thus, the total pressure of the flue gas flowing from the last stage turbine vane element 27 to the flue gas diffuser 31 through the last stage turbine blade element 28 can be set at an appropriate value in the radial direction. This can increase the amount of restoration of the pressure in the flue gas diffuser 31.
Note that, although both of the throat widths on the longitudinal tip side and base end side of the turbine vanes 27a are made larger than the throat width on the intermediate portion side in the second embodiment, only the throat width on the longitudinal tip side of the turbine vanes 27a or the throat width on the base end side can be made larger than the throat width on the intermediate portion side.
Applying a turbine employing both of the shapes of the turbine blades 28a on the turbine blade elements 28 in the first embodiment and the shapes of the turbine vanes 27a on the turbine vane elements 27 in the second embodiment can further improve the efficiency of the turbine and thus improve the performance.
11 Compressor
12 Combustor
13 Turbine
26 Turbine cylinder
27 Turbine vane element
27
a Last stage turbine vane
27
b Internal shroud
27
c External shroud
28 Turbine blade element
28
a Last stage turbine blade
28
b Rotor disk
29 Flue gas cylinder
30 Flue gas room
31 Flue gas diffuser
32 Rotor (Turbine shaft)
45 External diffuser
46 Internal diffuser
48 Strut
51 Turbine cylinder body
52 Vane ring
53 Split ring
54, 55, 56 Heat barrier ring
A Combustion gas passage
B Flue gas passage
| Number | Date | Country | Kind |
|---|---|---|---|
| 2011-076017 | Mar 2011 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2012/057592 | 3/23/2012 | WO | 00 | 10/24/2013 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2012/133224 | 10/4/2012 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 6004095 | Waitz | Dec 1999 | A |
| 6036438 | Imai | Mar 2000 | A |
| 6799948 | Ito | Oct 2004 | B2 |
| 7048509 | Tominaga | May 2006 | B2 |
| 8708639 | Subramaniyan | Apr 2014 | B2 |
| 20130064638 | Subramaniyan | Mar 2013 | A1 |
| Number | Date | Country |
|---|---|---|
| 1186900 | Jul 1998 | CN |
| 1547642 | Nov 2004 | CN |
| 101960101 | Jan 2011 | CN |
| 1422382 | May 2004 | EP |
| 1 584 786 | Oct 2005 | EP |
| 1 710 395 | Oct 2006 | EP |
| 2 412 922 | Feb 2012 | EP |
| 8-218803 | Aug 1996 | JP |
| 09-112203 | Apr 1997 | JP |
| 2000-45704 | Feb 2000 | JP |
| 2003-020904 | Jan 2003 | JP |
| 2004-263602 | Sep 2004 | JP |
| 3773565 | May 2006 | JP |
| 2009-203871 | Sep 2009 | JP |
| 2010-180827 | Aug 2010 | JP |
| 2011-021525 | Feb 2011 | JP |
| 2011-038491 | Feb 2011 | JP |
| 2011040241 | Apr 2011 | WO |
| Entry |
|---|
| Machhine translation of IDS ref JP 2003/020904. |
| Extended European Search Report dated Jul. 29, 2014, issued in European Patent Application No. 12763068.9 (6 pages). |
| Chinese Office Action dated Oct. 31, 2014, issued in corresponding CN Patent Application No. 201280016252.2 with English translation (22 pages). |
| Notification of the Decision to Grant a Patent Right for Patent for Invention dated Jul. 2, 2015, issued in counterpart Chinese Patent Application No. 201280016252.2, with English translation. (4 pages). |
| Office Action dated Dec. 8, 2015., issued in counterpart Japanese Patent Application No. 2011-076017, with English translation. (3 pages). |
| English translation of Written Opinion of PCT/JP2012/057592, mailing date of Apr. 17, 2012. |
| International Search Report of PCT/JP2012/057592, mailing date of Apr. 17, 2012. |
| Written Opinion of PCT/JP2012/057592, mailing date of Apr. 17, 2012. |
| Number | Date | Country | |
|---|---|---|---|
| 20140041395 A1 | Feb 2014 | US |
