Turbine

Abstract

To suppress an uneven flow to a moving blade.SOLUTION: A turbine 10 includes: a plurality of first stationary blades V1, where the plurality of first stationary blades V1 is arranged along a circumferential direction of a shaft and at least one first stationary blade V1 of the plurality of first stationary blades V1 has a blade outlet angle α2 different from blade outlet angles of the remaining first stationary blades V1.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to turbines. [Background technology]

[0002] In this technical field, various configurations for controlling the flow within a turbine have been proposed. For example, Patent Document 1 discloses a gas turbine including a combustor and a low-pressure turbine. The low-pressure turbine includes variable stator vanes whose mounting angles can be changed. In this gas turbine, the fuel flow rate consumed in the combustor is measured, and the mounting angle of the variable rotor vanes at the inlet of the low-pressure turbine is changed so that the ratio between the measured fuel flow rate and the air flow rate flowing into the combustor changes within a certain range. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 61-151044 Summary of the Invention [Problem to be solved by the invention]

[0004] In a turbine, the fluid may have a non-uniform temperature distribution in the circumferential direction, which can cause the fluid to flow unevenly onto the rotor blades, which can degrade the performance of the turbine.

[0005] The present disclosure aims to provide a turbine that can suppress uneven flow to rotor blades. [Means for solving the problem]

[0006] A turbine according to one embodiment of the present disclosure includes a plurality of first stator vanes arranged along the circumferential direction of a shaft, wherein the blade outlet angle of at least one of the plurality of first stator vanes is different from the blade outlet angles of the remaining first stator vanes.

[0007] The cross-sectional area of ​​the throat between adjacent first stator vanes may be constant among the plurality of first stator vanes.

[0008] The first vane, which is located in a region where a fluid having a higher temperature flows, may have a smaller vane exit angle.

[0009] The turbine may further include a plurality of second stator vanes arranged circumferentially and disposed downstream of the plurality of first stator vanes in the central axial direction of the shaft, the blade outlet angles of the second stator vanes being different from one another so as to vary along the circumferential direction, and the first stator vane having the smallest blade outlet angle among the plurality of first stator vanes and the second stator vane having the smallest blade outlet angle among the plurality of second stator vanes may be disposed at different positions from one another in the circumferential direction.

[0010] The smallest blade outlet angle of the plurality of first stator vanes may be different from the smallest blade outlet angle of the plurality of second stator vanes.

[0011] Another aspect of the present disclosure is a system including any of the turbines described above and a combustor disposed at a predetermined position relative to the turbine in the circumferential direction of the shaft. [Effects of the Invention]

[0012] According to the present disclosure, uneven flow to the rotor blades can be suppressed. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic diagram showing a power generation system including a turbine according to an embodiment. [Figure 2] FIG. 2 is a schematic partial cross-sectional view of the turbine in FIG. [Figure 3] FIG. 3 is a schematic cross-sectional view taken along line III-III in FIG. [Figure 4]FIG. 4 is a schematic cross-sectional view taken along line IV-IV in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Specific dimensions, materials, numerical values, etc. shown in the embodiments are merely examples for ease of understanding and do not limit the present disclosure unless otherwise specified. In this specification and drawings, elements having substantially the same functions and configurations are designated by the same reference numerals to avoid redundant explanation, and elements not directly related to the present disclosure are not shown.

[0015] FIG. 1 is a schematic diagram showing a power generation system 100 including a turbine 10 according to an embodiment. In this embodiment, the turbine 10 is applied to a power generation system (hereinafter, simply referred to as a "system") 100 including a power generation device 1. The application of the turbine 10 is not limited thereto, and the turbine 10 may be applied to various facilities other than power generation systems. The system 100 includes the power generation device 1, a compressor 2, a combustor 3, a shaft 4, and the turbine 10.

[0016] The compressor 2 compresses the intake air. The compressed air is supplied to the combustor 3 and mixed with fuel. The air and fuel mixture is combusted in the combustor 3. Exhaust gas from the combustor 3 is supplied to the turbine 10.

[0017] In the system 100, the combustor 3 is disposed at a specific position relative to the turbine 10. For example, in this embodiment, the combustor 3 is disposed above the turbine 10. In other words, if the vertically upward direction in the circumferential direction of the shaft 4 is set to 0 degrees, then in this embodiment, the combustor 3 is disposed at a position at 0 degrees relative to the turbine 10 in the circumferential direction. In yet another way, the combustor 3 is disposed at a position offset in the circumferential direction relative to the turbine 10. The position of the combustor 3 is not limited thereto, and the combustor 3 may be disposed above the turbine 10 or at a position other than 0 degrees.

[0018] Fig. 2 is a schematic partial cross-sectional view showing the turbine 10 in Fig. 1. The turbine 10 includes a housing 11. The turbine 10 also includes a portion of the shaft 4 described above. The shaft 4 extends within the housing 11.

[0019] In the present disclosure, the central axial direction, radial direction, and circumferential direction of the shaft 4 may be simply referred to as the central axial direction, radial direction, and circumferential direction, respectively, unless otherwise specified.

[0020] The housing 11 includes a connecting passage 12. The connecting passage 12 has an annular shape. The connecting passage 12 is located radially outward of the shaft 4. The connecting passage 12 is connected to the combustor 3 via a scroll passage (not shown). Exhaust gas g from the combustor 3 is supplied to the connecting passage 12 via the scroll passage.

[0021] The turbine 10 includes, in order from closest to the connecting flow passage 12 along the central axis direction, a first stator vane row VR1, a first rotor blade row BR1, a second stator vane row VR2, a second rotor blade row BR2, a third stator vane row VR3, and a third rotor blade row BR3.

[0022] The first stator vane row VR1 includes a plurality of first stator vanes V1 arranged along the circumferential direction. The first stator vanes V1 are fixed to the housing 11 and project radially inward from the housing 11. The first rotor blade row BR1 includes a plurality of first rotor blades B1 arranged along the circumferential direction. The first rotor blades B1 are fixed to the shaft 4 and project radially outward from the shaft 4. The second stator vane row VR2 includes a plurality of second stator vanes V2 arranged along the circumferential direction. The second stator vanes V2 are fixed to the housing 11 and project radially inward from the housing 11. The second rotor blade row BR2 includes a plurality of second rotor blades B2 arranged along the circumferential direction. The second rotor blades B2 are fixed to the shaft 4 and project radially outward from the shaft 4. The third stator vane row VR3 includes a plurality of third stator vanes V3 arranged along the circumferential direction. The third stator vane V3 is fixed to the housing 11 and protrudes radially inward from the housing 11. The third rotor blade row BR3 includes a plurality of third rotor blades B3 arranged along the circumferential direction. The third rotor blade B3 is fixed to the shaft 4 and protrudes radially outward from the shaft 4. In this embodiment, the stator vane is fixed to the outer stationary wall (housing 11), but a stationary wall may be provided on the inner side (hub side), or the stator vane may be attached to the inner stationary wall.

[0023] As the exhaust gas g passes through the first stator blade row VR1, the first rotor blade row BR1, the second stator blade row VR2, the second rotor blade row BR2, the third stator blade row VR3 and the third rotor blade row BR3, it causes the first rotor blade B1, the second rotor blade B2 and the third rotor blade B3 to rotate together with the shaft 4.

[0024] 1, the rotational force of the shaft 4 is used to generate power in the power generation device 1. The rotational force of the shaft 4 is also used to compress air in the compressor 2. The exhaust gas that has passed through the turbine 10 may be used in various facilities such as a boiler.

[0025] 3 is a schematic cross-sectional view taken along line III-III in FIG. 2, showing the cross-sectional shapes of the first stator vane V1 and the first rotor blade B1. The first stator vane V1 includes a pressure surface Vp and a suction surface Vs. The first stator vane V1 also includes a leading edge Ve and a trailing edge Vt.

[0026] The first stator vane V1 has a blade outlet angle α1. The blade outlet angle α1 is the angle between the pressure surface Vp and the central axis at the outlet of the pressure surface Vp. The exhaust gas g flows out of the first stator vane V1 along a direction inclined by the blade outlet angle α1 with respect to the central axis.

[0027] Between adjacent first stator vanes V1, the minimum distance between the suction surface Vs and the pressure surface Vp is defined as the throat th. For example, the throat th is formed by a perpendicular line drawn from the outlet of the pressure surface Vp to the suction surface Vs. In the present disclosure, the throat th is determined so that the flow rate of the exhaust gas g is kept constant between the first stator vanes V1, that is, so that the exhaust gas g is choked between the first stator vanes V1. The cross-sectional area of ​​the throat th is constant between the multiple first stator vanes V1.

[0028] The first rotor blade B1 has a cross-sectional shape that is roughly the same as that of the first stator vane V1 rotated 180 degrees around the central axis. The first rotor blade B1 includes a pressure surface Bp and a suction surface Bs. The first rotor blade B1 also includes a leading edge Be and a trailing edge Bt.

[0029] The blade outlet angle α1 of the first stator blade V1 is determined as follows.

[0030] When the exhaust gas g is choked between the first stator vanes V1, the cross-sectional area of ​​the throat th is constant among the multiple first stator vanes V1, and therefore the flow rate of the exhaust gas g is constant among all of the first stator vanes V1. In this case, the streamwise Mach number of the exhaust gas g along the central axis direction indicated by arrow M1 is constant among all of the first stator vanes V1. The absolute Mach number of the exhaust gas g along the blade outlet angle α1 is indicated by arrow M2. The relationship between the streamwise Mach number M1 and the absolute Mach number M2 is as shown in Figure 3.

[0031] The peripheral Mach number of the first rotor blade B1 along the direction of rotation is indicated by a solid arrow M3. The peripheral Mach number M3 is expressed by the following equation (1).

[0032]

number

[0033] however, U: Rotational speed of the first rotor blade B1 γ: specific heat ratio of exhaust gas g R: Gas constant of exhaust gas g T: Temperature of exhaust gas g The denominator in equation (1) corresponds to the speed of sound.

[0034] The relative Mach number of the exhaust gas g as seen from the first rotor blade B1 is indicated by a solid arrow M4. The relative Mach number M4 can be expressed as shown in Figure 3 using the absolute Mach number M2 and the peripheral Mach number M3. That is, as seen from the first rotor blade B1, the exhaust gas g flows into the space between the first rotor blades B1 along the direction of the solid arrow M4. The blade outlet angle α1 of the first stator vane V1 is determined so that the exhaust gas g indicated by the arrow M4 flows toward the pressure surface Bp.

[0035] As can be seen from equation (1) above, as the temperature T of the exhaust gas g increases, the peripheral Mach number M3 of the first rotor blade B1 decreases. As shown in FIG. 3, if the peripheral Mach number M3 decreases as indicated by the dashed arrow, the relative Mach number M4 also changes as indicated by the dashed arrow. In this case, the exhaust gas g flows along the direction of the dashed arrow M4, and therefore flows toward the suction surface Bs of the first rotor blade B1. This flow can degrade the performance of the turbine 10.

[0036] 1 and 2, as described above, the high-temperature exhaust gas g is supplied to the connecting passage 12 from the combustor 3, which is positioned offset in the circumferential direction relative to the turbine 10. Therefore, the scroll flow of the exhaust gas g flowing into the turbine 10 may have a non-uniform temperature distribution in the circumferential direction. Therefore, in a region where the temperature T of the exhaust gas g is high, as can be understood from the above equation (1), the peripheral Mach number M3 of the first rotor blade B1 decreases, and the exhaust gas g flows toward the suction surface Bs of the first rotor blade B1. In the present disclosure, the blade outlet angle of the first stator vane V1 located in such a region where the temperature T of the exhaust gas g is high is determined so that the exhaust gas g flows correctly toward the pressure surface Bp of the first rotor blade B1. With reference to FIG. 2, in this embodiment, for better understanding, the first stator vane row VR1 will be described as having the highest temperature T of the exhaust gas g in a region below the shaft 4 in FIG. 2. However, the temperature distribution of the exhaust gas g is not limited to this, and may vary depending on various factors such as the position of the combustor 3 and the lengths of the scroll passage and the connecting passage 12. When the turbine 10 is operating at rated output, the position of this non-uniform temperature distribution is generally constant.

[0037] FIG. 4 is a schematic cross-sectional view taken along line IV-IV in FIG. 2, showing the cross-sectional shapes of the first stator vane V1 and the first rotor blade B1 arranged in a region where the temperature T of the exhaust gas g is high. For better comparison, the cross-sectional shape of the first stator vane V1 in FIG. 3 is shown by a dashed line. Similarly, the absolute Mach number M2 and the peripheral Mach number M3 in FIG. 3 are each shown by a dashed line. As described above, when the exhaust gas g is choked between the first stator vanes V1, the streamwise Mach number M1 is constant between all of the first stator vanes V1. Therefore, the streamwise Mach number M1 does not change from FIG. 3.

[0038] In the region shown in FIG. 4, the temperature T of the exhaust gas g is high, so the circumferential Mach number M3 shown by the solid line is smaller than the circumferential Mach number M3 shown by the dashed-dotted line in FIG. 3. However, even when the circumferential Mach number M3 is small, the angle of the arrow M2 indicating the absolute Mach number, i.e., the blade outlet angle α2 of the first stator vane V1, is set smaller than the above-mentioned blade outlet angle α1 so that the arrow M4 indicating the relative Mach number remains unchanged from FIG. 3. With this configuration, even in the region where the temperature T of the exhaust gas g is high, the exhaust gas g flows correctly toward the pressure surface Bp of the first rotor blade B1, as indicated by the arrow M4 indicating the relative Mach number. Furthermore, the blade outlet angle varies circumferentially between the multiple first stator vanes V1 within a range of α1 or less and α2 or more. For example, the blade outlet angle of the multiple first stator vanes V1 may vary smoothly and continuously within a range of α1 or less and α2 or more. Also, for example, the blade outlet angles of only some of the first stator vanes V1 may be α2, and the blade outlet angles of all the remaining first stator vanes V1 may be α1. That is, the blade outlet angles of the multiple first stator vanes V1 may change in a stepwise manner between α1 and α2.

[0039] Referring to FIG. 2, in the turbine 10, the blade outlet angles of the second stator blade row VR2 and the third stator blade row VR3 are also set in the same manner as above.

[0040] Specifically, among the multiple second stator vanes V2, the blade outlet angle of the second stator vane V2 arranged in a region where the temperature T of the exhaust gas g is high is smaller than the blade outlet angle of the second stator vane V2 arranged in other regions. Furthermore, the exhaust gas g is rotated by the first rotor blade row BR1 before flowing into the second stator vane row VR2. Therefore, the region in the second stator vane row VR2 where the temperature T of the exhaust gas g is high may be located at a different position in the circumferential direction from the region in the first stator vane row VR1 where the temperature T of the exhaust gas g is high. In this case, the first stator vane V1 having the smallest blade outlet angle α2 and the second stator vane V2 having the smallest blade outlet angle are arranged at different positions in the circumferential direction.

[0041] The exhaust gas g flowing from the stator vane row VR1 into the rotor blade B1 is transported in the circumferential direction by the rotor blade B1. In this embodiment, the second stator vane V2 having the smallest blade outlet angle is provided at a circumferential position shifted in the rotation direction of the rotor blade B1 relative to the first stator vane V1 having the smallest blade outlet angle α2. In other words, when viewed in the direction of the rotation axis, the second stator vane V2 having the smallest blade outlet angle is provided at a position that forms a minor angle in the rotation direction of the rotor blade B1 relative to the first stator vane V1 having the smallest blade outlet angle α2. Furthermore, the multiple second stator vane rows VR2 in this embodiment have a blade outlet angle distribution that corresponds to that of the first stator vane row VR1. In other words, the number of maximum and minimum blade outlet angles of the circumferentially arranged stator vane rows is the same between the second stator vane row VR2 and the first stator vane row VR1.

[0042] Furthermore, the temperature T of the exhaust gas g may decrease while the exhaust gas g flows from the first stator vane row VR1 to the second stator vane row VR2. In this case, the adjustment amount of the blade outlet angle may differ between the first stator vane row VR1 and the second stator vane row VR2. In this case, the smallest blade outlet angle α2 of the multiple first stator vanes V1 is different from the smallest blade outlet angle of the multiple second stator vanes V2. Specifically, the smallest blade outlet angle α2 of the multiple first stator vanes V1 is smaller than the smallest blade outlet angle of the multiple second stator vanes V2.

[0043] Similarly, among the multiple third stator vanes V3, the blade outlet angle of the third stator vane V3 arranged in a region where the temperature T of the exhaust gas g is high is smaller than the blade outlet angle of the third stator vane V3 arranged in other regions. Furthermore, the exhaust gas g is rotated by the second rotor blade row BR2 before flowing into the third stator vane row VR3. Therefore, the region in the third stator vane row VR3 where the temperature T of the exhaust gas g is high may be located at a different position in the circumferential direction from the region in the second stator vane row VR2 where the temperature T of the exhaust gas g is high. In this case, the second stator vane V2 having the smallest blade outlet angle and the third stator vane V3 having the smallest blade outlet angle are arranged at different positions in the circumferential direction.

[0044] Furthermore, the temperature T of the exhaust gas g may decrease while the exhaust gas g flows from the second stator vane row VR2 toward the third stator vane row VR3. In this case, the adjustment amount of the blade outlet angle may differ between the second stator vane row VR2 and the third stator vane row VR3. In this case, the smallest blade outlet angle of the multiple second stator vanes V2 is different from the smallest blade outlet angle of the multiple third stator vanes V3. Specifically, the smallest blade outlet angle of the multiple second stator vanes V2 is smaller than the smallest blade outlet angle of the multiple third stator vanes V3.

[0045] The turbine 10 as described above includes a plurality of first stator vanes V1 arranged along the circumferential direction of the shaft 4, wherein the blade outlet angle α2 of at least one of the plurality of first stator vanes V1 is different from the blade outlet angles α1 of the remaining first stator vanes V1. According to this configuration, by setting the blade outlet angles α1, α2 of each first stator vane V1 in accordance with the temperature distribution of the fluid (exhaust gas g) in the circumferential direction so that the exhaust gas g flowing out of the first stator vane V1 flows toward the pressure surface Bp of the first rotor blade B1, it is possible to suppress uneven flow to the first rotor blade B1.

[0046] Furthermore, in the turbine 10, the cross-sectional area of ​​the throat th between adjacent first stator vanes V1 is constant among the multiple first stator vanes V1. With this configuration, the flow direction Mach number M1 of the exhaust gas g along the central axis direction can be made constant among all first stator vanes V1. Therefore, the calculation of the blade outlet angles α1 and α2 can be simplified.

[0047] Furthermore, in the turbine 10, the first stator vane V1 arranged in an area where the temperature T of the exhaust gas g is higher has a smaller blade outlet angle α2. With this configuration, the direction of the exhaust gas g can be controlled so that it flows toward the pressure surface Bp of the first rotor blade B1.

[0048] The turbine 10 further includes a plurality of second stator vanes V2 arranged circumferentially and disposed downstream of the plurality of first stator vanes V1 in the central axis direction, the plurality of second stator vanes V2 having different blade outlet angles that vary along the circumferential direction, and the first stator vane V1 having the smallest blade outlet angle α2 among the plurality of first stator vanes V1 and the second stator vane V2 having the smallest blade outlet angle among the plurality of second stator vanes V2 are disposed at different positions in the circumferential direction. With this configuration, by setting the blade outlet angles of the first stator vane V1 and the second stator vane V2 in accordance with the temperature distribution of the exhaust gas g in each of the first stator vane V1 and the second stator vane V2, it is possible to suppress uneven flow to the multiple stages of rotor blades B1, B2.

[0049] Furthermore, in the turbine 10, the smallest blade outlet angle α2 of the multiple first stator vanes V1 is different from the smallest blade outlet angle of the multiple second stator vanes V2. With this configuration, the blade outlet angles of the first stator vane V1 and the second stator vane V2 can be set in accordance with the temperature drop of the exhaust gas g as it flows from the first stator vane V1 to the second stator vane V2.

[0050] The power generation system 100 also includes the turbine 10 as described above, and a combustor 3 that is disposed at a predetermined position in the circumferential direction relative to the turbine 10. With this configuration, uneven temperature distribution of the exhaust gas g is likely to occur in the circumferential direction, and therefore the turbine 10 can more effectively exhibit the effects described above.

[0051] Although the embodiments have been described above with reference to the accompanying drawings, the present disclosure is not limited to the above-described embodiments. It is clear that a person skilled in the art can conceive of various modifications or alterations within the scope of the claims, and it is understood that such modifications also fall within the technical scope of the present disclosure.

[0052] For example, in the above embodiment, the turbine 10 includes three sets of stator vanes V1, V2, and V3 and rotor blades B1, B2, and B3. However, in other embodiments, the turbine 10 may include only the stator vane V1 and rotor blade B1, or may include four or more sets of stator vanes and rotor blades.

[0053] In the above embodiment, the blade outlet angle varies along the circumferential direction in all of the first stator vane V1, the second stator vane V2, and the third stator vane V3. However, in other embodiments, the blade outlet angle may vary along the circumferential direction in at least one of the first stator vane V1, the second stator vane V2, and the third stator vane V3.

[0054] In the above embodiment, the first stator vane V1, the second stator vane V2, and the third stator vane V3 are fixed to the housing 11. However, in other embodiments, at least one of the first stator vane V1, the second stator vane V2, and the third stator vane V3 may be movable so that the blade outlet angle is changeable. In this case, for example, the turbine 10 may include a temperature sensor that measures the temperature distribution of the exhaust gas around the movable stator vane, and a control device that controls the blade outlet angle of the movable stator vane. The control device may adjust the blade outlet angle of the movable stator vane based on the temperature distribution of the exhaust gas measured by the temperature sensor.

[0055] For example, the present disclosure can contribute to improving the performance and reliability of emergency power generation equipment, thereby contributing to Sustainable Development Goal (SDG) 7, "Ensure access to affordable, reliable, sustainable and modern energy." [Explanation of symbols]

[0056] 3 Combustor 4 shafts 10 Turbine 100 Power Generation System th throat V1 First stator vane V2 Second stator vane (first stator vane) V3 Third stator vane (Second stator vane) α1 Blade exit angle α2 Blade exit angle

Claims

1. a plurality of first stator vanes arranged along a circumferential direction of the shaft, wherein a blade outlet angle of at least one of the plurality of first stator vanes is different from the blade outlet angles of the remaining first stator vanes; A turbine comprising:

2. The turbine according to claim 1 , wherein a cross-sectional area of ​​a throat between adjacent first stator vanes is constant among the plurality of first stator vanes.

3. 3. The turbine of claim 1, wherein the first vanes located in the region of higher fluid temperature have a smaller vane exit angle.

4. a plurality of second stator vanes arranged along the circumferential direction and disposed downstream of the plurality of first stator vanes in a central axial direction of the shaft, the plurality of second stator vanes having blade outlet angles different from one another so as to vary along the circumferential direction; Furthermore, 4. The turbine according to claim 1, wherein a first stator vane having a smallest blade outlet angle among the plurality of first stator vanes and a second stator vane having a smallest blade outlet angle among the plurality of second stator vanes are arranged at different positions in the circumferential direction.

5. The turbine of claim 4 , wherein a smallest blade exit angle of the plurality of first vanes is different from a smallest blade exit angle of the plurality of second vanes.

6. A turbine according to any one of claims 1 to 5; a combustor positioned at a predetermined position relative to the turbine in the circumferential direction of the shaft; A system comprising: