JP5479624B2 - Turbine blade and gas turbine - Google Patents

Description

  The present invention relates to a turbine blade and a gas turbine including the turbine blade.

  In a gas turbine, high-temperature combustion gas generated by mixing air pressurized in a compressor with fuel in a combustor is injected into a turbine flow path in which stationary blades and moving blades are alternately arranged to move the gas turbine. By rotating the blades and the rotor, the energy of the high-temperature combustion gas is output as rotational energy, and the compressor is powered.

  Here, the turbine blade constituting the stationary blade or the moving blade includes a blade body having a blade shape and a blade end wall provided at the blade body end. In the vicinity of the blade end wall, as shown in FIG. 8A, so-called crossflow CF is generated from the side of the abdominal surface 101 of one turbine blade 100 toward the back surface 103 of the adjacent turbine blade 102. When the crossflow CF collides with the back surface portion 103, so-called roll-up V is also generated in the back surface portion 103 as shown in FIG. Since these become losses and reduce the turbine performance, it is necessary to reduce these, and to reduce the secondary flow loss generated due to the crossflow or winding.

  In order to improve the turbine performance by reducing such secondary flow loss, the front edge side of the fillet covering the connecting portion between the blade body and the blade end wall is enlarged (see, for example, Patent Document 1). ) And a modified shape of the wing tip wall on the trailing edge side (see, for example, Patent Document 2).

JP 2004-278517 A JP 2007-247542 A

  However, even with the above-described conventional technology, it is not possible to eliminate the cross flow and the roll-up, and the occurrence of pressure loss still exists. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a turbine blade and a gas turbine capable of appropriately suppressing a pressure loss and improving turbine performance.

The present invention employs the following means in order to solve the above problems.
The present invention provides a wing body in which a convex back surface portion and a concave abdominal surface portion are disposed between a leading edge and a trailing edge, a wing end wall to which an end portion of the wing body is connected, and the wing A turbine blade including a fillet that covers a periphery of a connection portion between the end wall and the blade body, and protrudes in the height direction and the width direction more than twice the height and width of the fillet at the leading edge. And the center of the apex is within the range of 20% to 80% of the axial cord length from the leading edge to the trailing edge with respect to the leading edge. An enlarged portion that gradually spreads in the height direction and the width direction from the front edge side and the rear edge side toward the top portion is arranged in the fillet on the abdominal surface side, and is orthogonal to the height direction. In the cross sectional view, the enlarged portion is more than the straight line connecting the front edge and the rear edge. And it is located on the surface side.

In the present invention, the pressure on the abdominal surface side in the vicinity of the blade tip wall can be reduced by the top portion arranged on the fillet, and the pressure difference with the back surface side can be reduced. Therefore, it is possible to suppress the cross flow and suppress the roll-up in the vicinity of the rear portion blade end wall due to the collision between the rear portion and the cross flow, thereby suppressing the loss due to the secondary flow.
Moreover, the pressure difference between the abdominal surface portion side and the back surface portion side can be further reduced, and the crossflow can be more suitably suppressed.

  Further, in the above turbine blade, a reduced portion that decreases in the height direction and the width direction to 50% or less of the height and width of the fillet at the leading edge is disposed in the fillet on the back surface side, and The center of the reduced portion is disposed within a range of 20% to 80% of the axial cord length from the leading edge to the throat position between the adjacent wing body with respect to the leading edge. preferable.

  According to the present invention, the pressure on the back surface side in the vicinity of the blade tip wall can be increased by the reduced portion disposed on the fillet, and the pressure difference with the back surface side can be reduced. Therefore, it is possible to suppress the cross flow and suppress the roll-up in the vicinity of the rear portion blade end wall due to the collision between the rear portion and the cross flow, thereby further suppressing the loss due to the secondary flow.

  In the turbine blade described above, it is preferable that the contraction portion is disposed on the fillet on the back surface portion side so as to gradually contract in the height direction and the width direction from the front edge side and the throat position side.

  According to the present invention, the pressure difference between the abdominal surface portion side and the back surface portion side can be further reduced, and the crossflow can be more suitably suppressed.

  In the turbine blade described above, it is preferable that the fillet disposed on the trailing edge is provided with an extension extending rearward from the trailing edge with a length that is twice or more the blade thickness on the trailing edge. .

  According to the present invention, the fluid flowing along the extending portion arranged in the fillet can be rectified behind the trailing edge, and the flow from the abdominal surface side and the back surface side collides behind the trailing edge to increase the pressure. As a result, the roll-up in the vicinity of the blade tip wall behind the trailing edge can be suppressed, and the loss due to the secondary flow can be further suppressed.

  Moreover, the gas turbine of this invention is equipped with said turbine blade, It is characterized by the above-mentioned.

  The present invention can improve performance by suppressing the secondary flow loss by the turbine blade.

According to the turbine blade of the present invention, it is possible to suitably suppress the pressure loss in the vicinity of the blade end wall and improve the turbine performance.
Further, according to the gas turbine of the present invention, the performance can be improved by the turbine blade.

It is a partially broken sectional view which shows the gas turbine by which the turbine stationary blade concerning one Embodiment of this invention is distribute | arranged. It is the schematic which shows the principal part of the turbine stationary blade which concerns on one Embodiment of this invention. It is sectional drawing which shows the cascade of the turbine stationary blade which concerns on one Embodiment of this invention. It is sectional drawing in the blade end wall which shows the turbine stationary blade which concerns on one Embodiment of this invention. It is sectional drawing in the blade end wall which shows the turbine stationary blade which concerns on one Embodiment of this invention. It is a figure which respectively shows (a) the pressure distribution analysis result in the conventional turbine stationary blade, (b) The pressure distribution analysis result in the turbine stationary blade which concerns on one Embodiment of this invention. It is a graph which shows the loss analysis result in the conventional turbine stationary blade and the turbine stationary blade which concerns on one Embodiment of this invention. (A) It is explanatory drawing which shows the cross flow in a turbine blade, and (b) winding up, respectively.

An embodiment according to the present invention will be described with reference to FIGS. 1 to 5.
As shown in FIG. 1, turbine stationary blades (turbine blades) 1 and turbine blades (turbine blades) 2 according to the present embodiment are alternately arranged in multiple stages in a turbine 3 along the direction of the axis O. The turbine 3 is disposed in a gas turbine 7 together with a compressor 5 that generates compressed air and a combustor 6 that supplies fuel to the compressed air supplied from the compressor 5 to generate combustion gas.

  Here, the configuration and operation / effect according to the present invention are the same as those of the turbine stationary blade 1 or the turbine rotor blade 2. Therefore, hereinafter, in the present embodiment, the turbine stationary blade 1 will be described as shown in FIG. 2, and the description of the turbine rotor blade 2 will be omitted.

  As shown in FIGS. 2 and 3, the turbine stationary blade 1 is a blade in which a convex back surface portion 11 and a concave abdominal surface portion 12 are arranged with respect to a chord C connecting the leading edge 8 and the trailing edge 10. A main body 13, a wing end wall 15 to which an end of the wing main body 13 is connected, and a fillet 16 that covers the periphery of the connection portion CO between the wing end wall 15 and the wing main body 13 are provided.

  The wing body 13 is spaced apart at a predetermined interval in the circumferential direction of the wing end wall 15 with the axis O as the central axis, and the back surface portion 11 side and the abdominal surface portion 12 side of the adjacent wing body 13 are opposed to each other. Are arranged. And the mainstream passes between the adjacent wing bodies 13. The back surface portion 11 and the abdominal surface portion 12 are formed in a predetermined shape.

  Here, when the blade height direction is the height direction H and the blade width direction is the width direction W, as shown in FIG. 4, the fillet 16 disposed on the abdominal surface portion 12 side includes the fillet 16 at the leading edge 8. The tops 17 projecting from the connection part CO in the height direction H and the width direction W are arranged at least twice the height and width.

  The center of the top portion 17 is based on the position of the front edge 8 and is 20% (indicated by the L1 line in the drawing) to 80% (indicated by the L2 line in the drawing) of the axial cord length L from the leading edge 8 to the rear edge 10. It is arranged within the range of An enlarged portion 18 that gradually spreads in the height direction H and the width direction W from the front edge 8 side and the rear edge 10 side toward the top portion 17 so as to connect the top portion 17 to the fillet 16 of the front edge 8 and the rear edge 10. Arranged in the fillet 16.

  In addition, the fillet 16 disposed on the trailing edge 10 of the blade body 13 has an extended portion 20 extending further rearward from the trailing edge 10 with a length of twice or more, preferably twice or more the blade thickness of the trailing edge 10. It is arranged.

  Further, as shown in FIG. 5, the fillet 16 on the back surface part 11 side has a reduced portion 21 that is reduced in the height direction H and the width direction W to 50% or less of the height and width of the fillet 16 at the front edge 8. Is arranged. The center of the reduced portion 21 is 20% of the axial code length L ′ from the leading edge 8 to the throat position S between the adjacent wing body 13 with reference to the position of the leading edge 8 (line L3 in the figure). To 80% (indicated by the L4 line in the figure).

  The reduction part 21 is disposed on the fillet 16 so as to gradually shrink in the height direction H and the width direction W from the front edge 8 side and the throat position S side so as to connect to the front edge 8 and the fillet 16 at the throat position S. ing.

  According to the turbine vane 1, the flow of fluid in the vicinity of the blade end wall 15 can be changed along the enlarged portion 18 and the top portion 17 arranged in the fillet 16, and the abdominal surface portion 12 in the vicinity of the blade end wall 15. The pressure difference with the back surface part 13 side can be reduced smoothly by reducing the pressure on the side. Therefore, the cross flow can be suitably suppressed, and the roll-up in the vicinity of the blade end wall 15 of the back surface portion 13 due to the collision between the back surface portion 13 and the cross flow can be suppressed. Therefore, the loss of fluid passing through the turbine stationary blade 1 can be suitably reduced.

  Further, the fluid flows rearward from the trailing edge 10 along the extending portion 20 arranged in the fillet 16, whereby the flow behind the trailing edge 10 can be rectified. Thus, the flow from the abdominal surface portion 12 side and the back surface portion 11 side is preferably prevented from colliding behind the trailing edge 10 and increasing the pressure, whereby the winding from the blade end wall 15 behind the trailing edge 10 is achieved. And the loss of fluid can be further reduced.

  Further, the reduction part 21 arranged in the fillet 16 can increase the pressure on the back surface part 11 side in the vicinity of the blade end wall 15 and can smoothly reduce the pressure difference with the abdominal surface part 12 side. Therefore, the cross flow can be suitably suppressed, and the roll-up in the vicinity of the blade end wall 15 of the back surface portion 13 due to the collision between the back surface portion 13 and the cross flow can be further suppressed.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, the respective height and width dimensions of the top portion 17 or the reduced portion 21 may be the same as or different from each other. Further, as described above, not only the turbine stationary blade 1 but also the turbine rotor blade 2 may be used.

  When only the top portion 17 and the enlarged portion 18 were disposed on the fillet 16, the static pressure distribution in the blade tip wall 15 was analyzed. The position of the top 17 was 50%. Further, the height and width of the top portion 17 were each twice the height and width of the fillet 16. The results are shown in FIG. In addition, the isobaric distribution line shows a high pressure in the order of a solid line, a dotted line, a one-dot chain line, a solid line, a dotted line,. As shown in FIG. 6A, in contrast to the comparative example in which the top portion 17 and the enlarged portion 18 are not arranged, in this embodiment, in the vicinity of the top portion 17 and the enlarged portion 18 as shown in FIG. 6B. The direction of the isobaric distribution line is different. That is, the pressure in the vicinity of the blade end wall 15 in the abdominal surface portion 12 is reduced, thereby indicating a pressure distribution along the abdominal surface portion 12 and the back surface portion 11, and the back surface portion of the adjacent turbine blade from the abdominal surface portion 12 side. It was found that the driving force of the cross flow flowing toward No. 11 was reduced and weakened.

  Moreover, the average value of the loss in the circumferential direction at an arbitrary position in the blade height direction from the blade end wall of the turbine blade was analyzed in correspondence with the analysis result of FIG. The results are shown in FIG. It has been found that the loss in the vicinity of the blade tip wall 15 is lower than that in the comparative example, so that the loss is also reduced in the entire blade height direction.

1 Turbine vane (turbine blade)
2 Turbine blade (turbine blade)
7 Gas turbine 8 Leading edge 10 Trailing edge 11 Back face 12 Abdominal face 13 Blade body 15 Blade end wall 16 Fillet 17 Top 18 Expanding part 20 Extending part 21 Reduction part CO Connecting part L, L 'Axial cord length S Throat position

Claims (5)

A wing body in which a convex back surface portion and a concave abdominal surface portion are disposed between a front edge and a rear edge, a wing end wall to which an end of the wing body is connected, the wing end wall, A fillet covering the periphery of the connection with the blade body, and a turbine blade comprising:
A top portion protruding in the height direction and the width direction more than twice the height and width of the fillet at the front edge is disposed on the fillet on the abdominal surface side,
The center of the top is disposed within a range of 20% to 80% of the axial cord length from the leading edge to the trailing edge with respect to the leading edge;
An enlarged portion that gradually spreads in the height direction and the width direction from the front edge side and the rear edge side toward the top portion is disposed on the fillet on the abdominal surface portion side,
The turbine blade according to claim 1, wherein the enlarged portion is positioned closer to the abdominal surface than a straight line connecting the front edge and the rear edge in a cross-sectional view orthogonal to the height direction. Reduced portions respectively reduced in the height direction and the width direction to 50% or less of the height and width of the fillet at the front edge are arranged in the fillet on the back side,
The center of the reduced portion is disposed within the range of 20% to 80% of the axial cord length from the leading edge to the throat position between the adjacent wing body with respect to the leading edge. The turbine blade according to claim 1.   3. The turbine according to claim 2, wherein the contraction portion is disposed in the fillet on the back surface portion side so as to gradually contract in the height direction and the width direction from the front edge side and the throat position side. Wings.   4. The extension according to claim 1, wherein the fillet disposed on the trailing edge is provided with an extension extending rearward from the trailing edge having a length of at least twice the blade thickness at the trailing edge. The turbine blade according to any one of the above.   A gas turbine comprising the turbine blade according to any one of claims 1 to 4.

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