JP2007321644A - Turbine nozzle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a turbine nozzle enabling the working steps such as manufacture, processing, assembly to be further simplified and shortened and further increased in performance. <P>SOLUTION: This turbine nozzle comprises a blade body 1 having a leading edge facing the inlet side of a working fluid and a trailing edge positioned on the outlet side of the working fluid, and a front side 4 formed of one contour line and a rear side 5 formed of the other contour line formed by connecting these leading edge 2 and trailing edge 3 with two contour lines. Blade body support parts 2a, 2b are mounted on the blade outer diameter side and the blade inner diameter side of the blade body 1, respectively. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a turbine nozzle, and more particularly to a turbine nozzle in which a process for further simplification and shortening in manufacturing operations is added.

  In recent steam turbines, performance and reliability have been strengthened and reviewed as competition has intensified, and one of the targets is a turbine nozzle.

  There are several types of turbine nozzles. For example, as shown in FIG. 3, when the both ends of the blade body 10 are sandwiched and supported by the diaphragm outer ring 11 and the diaphragm inner ring 12, they are connected to each other using the welded portion 4. There is a so-called welding type.

  In this welding type turbine nozzle, as shown in FIG. 4, first, the nozzle blade body 10 and the spacers 14a and 14b are separately prepared, and then the spacers 14a and 14b are used for the nozzle blade body. After the holes 15a and 15b are drilled and both ends of the blade body 10 are inserted and fitted into the nozzle blade body holes 15a and 15b, the diaphragm outer ring 11 is welded using the welded portion 13 as shown in FIG. And fixedly connected to each of the diaphragm inner rings 12.

  Further, as shown in FIG. 5, another welding type turbine nozzle is produced by integrally producing the blade body 10 and the curved plate-like sidewalls (blade covers) 16a and 16b by precision casting or the like. As shown in FIG. 3, curved plate-like sidewalls 16a and 16b are connected to each of the diaphragm outer ring 11 and the diaphragm inner ring 12 by fillet welding on the entire circumference.

  On the other hand, the blade body 10 includes a taper nozzle blade or an improved nozzle blade (AFP = Advance Flow Pattern nozzle blade) obtained by improving a so-called straight blade in accordance with a measure for improving performance. A number of proposals such as Patent Document 3 have been proposed, and some of them have been put into practical use.

  Here, the taper nozzle blade is a blade body that gradually increases the blade cross-sectional area from the blade root toward the blade top.

Among many improved nozzle blades, for example, the nozzle blades found in Patent Documents 1 and 2 have a convex curve in the blade height direction intermediate portion of the blade body 10 from the back side to the ventral side. This is a so-called three-dimensional wing body.
JP-A-1-106903 JP-A-4-124406 JP 61-108804 A

  Recent turbine nozzles may have some problems when the blade body 10 becomes a so-called three-dimensional shape that is sophisticated and complicated by combining straight lines and curves as seen in the above-mentioned patent document. It has become.

  For example, in the spacer insertion type turbine nozzle, when the holes 14a and 15b for the nozzle blade body are drilled in the spacers 14a and 14b, after the laser blade or wire cut is performed, the blade body 10 is moved to the nozzle blade body hole 15a, Rubbing with a grinder was performed so that it could be inserted into and fitted into 15b, but if the shape of the wing body 10 becomes a sophisticated and complicated three-dimensional shape as described above, manufacturing, processing, assembly, etc. A lot of work time was spent on this process, and the labor burden on the worker was increased.

  Further, when the blade body 10 is inserted into and fitted into the nozzle blade body holes 15a and 15b, and is subjected to a rubbing process by a grinder, the dimensional position as designed is ensured because it is a manual operation. In addition, there is a processing error in the minimum area of the steam passage (throat area) and the position interval between the blade body 10 and the adjacent blade body 10 (blade pitch). There were problems such as turbulence and adversely affecting blade efficiency.

  In addition, in the case of a sidewall-integrated turbine nozzle, if the shape of the blade body 10 becomes more sophisticated and complicated, problems in quality assurance such as poor hot water and missing molds may occur during precision casting. 6 and 7, the radius of curvature R of the connecting portion (base portion) between the blade body 10 and the curved plate-like sidewalls 16a and 16b must be ensured to be large. Disappear.

  However, when the radius of curvature R of the connecting portion between the blade body 10 and the curved plate-like sidewalls 16a and 16b increases, the working fluid passes between the blade rows of the blade bodies 10 and 10, as shown in FIG. Passage vortices and counter vortices associated with the secondary flow generated at this time grew at the connecting portion of the back side 17 having a large radius of curvature R, causing a reduction in blade efficiency.

  The present invention has been made based on such circumstances, and provides a turbine nozzle that further simplifies and shortens work processes such as manufacturing, processing, and assembly, and further improves performance. The purpose is to do.

  In order to achieve the above object, a turbine nozzle according to the present invention includes a front edge that faces the inflow side of the working fluid, a rear edge that is positioned on the outlet side of the working fluid, In a turbine nozzle having a blade body formed by connecting an edge and a trailing edge with two contour lines, and having a blade body formed by a ventral side formed by one contour line and a dorsal side formed by the other contour line, the blade outer diameter of the blade body A blade body support plate is provided on each of the blade inner side and the blade inner diameter side.

  Further, in order to achieve the above-described object, the turbine nozzle according to the present invention has a blade body support plate provided on the blade outer diameter side of the blade body, with a radial line and a trailing edge. A horizontal plane passing through the intersection with the contour line is used as a reference plane, and both end surfaces of the reference plane are extended from the intersection and are translated into the radial line.

  Further, in order to achieve the above-described object, the turbine nozzle according to the present invention is characterized in that the blade body support plate provided on the blade inner diameter side of the blade body has a radial line and a contour of the trailing edge. A horizontal plane passing through the intersection with the line is used as a reference plane, and both end faces of the reference plane are extended from the intersection and are configured to move parallel to the radial line.

  The turbine nozzle according to the present invention is provided with a blade body support plate on each of the blade outer diameter side and the blade inner diameter side of the blade body, and the blade body support plate has a horizontal plane passing through the intersection of the radial line and the contour line of the trailing edge. As the reference surface, both end surfaces of this reference surface are extended from the above-mentioned intersections and are configured to move parallel to the radial line, so that the assembly work of the wing body to the diaphragm outer ring and the diaphragm inner ring can be easily performed. It can be installed accurately and quickly at the designed position, and the blade efficiency can be improved.

  Hereinafter, embodiments of a turbine nozzle according to the present invention will be described with reference to the drawings and reference numerals attached to the drawings.

  FIG. 1 is a conceptual diagram showing an embodiment of a turbine nozzle according to the present invention.

  The turbine nozzle according to the present embodiment connects the front edge 2 facing the working fluid inflow side, the rear edge 3 positioned on the working fluid outflow side, and the front edge 2 and the rear edge 3 by two contour lines, The wing body 1 is composed of a ventral side 4 formed by one contour line and a dorsal side 5 formed by the other contour line.

  The blade body 1 has various blade types. For example, as shown in FIG. 1, the blade outer diameter side line with respect to a radial line (radial line) RL passing through the center of a turbine rotor (not shown). Both the BOL and the blade inner diameter side line BIL are linearly inclined toward the abdominal side 4 while the blade main body intermediate line BML is curved toward the abdominal side 4.

  Further, on each of the blade outer diameter side OD and the blade inner diameter side ID of the blade main body 1, flat blade main body support plates 2a and 2b are provided integrally by precision casting or by welding connection.

On the other hand, as shown in FIG. 2, the flat blade body support plates 2a and 2b have a horizontal plane passing through the intersection point O of the radial line (radial line) RL and the contour line TL of the trailing edge 3 as a reference plane (HL ₁ (HL ₂ )), and both end face lines E ₀₁ (E ₁₁ ) and E ₀₂ (E ₂₂ ) of the reference plane (HL ₁ (HL ₂ )) are extended from the intersection point O, and the radial line RL It is formed by parallel translation.

As described above, in the present embodiment, the flat blade body support plates 2a and 2b provided on the blade outer diameter side OD and the blade inner diameter side ID of the blade body 1 are provided with the radial line RL and the contour line TL of the trailing edge 3, respectively. A horizontal plane passing through the intersection O with the reference plane is placed on the reference plane, and both end faces E ₀₁ (E ₁₁ ) and E ₀₂ (E ₂₂ ) of these reference planes (HL ₁ (HL ₂ )) are extended from the intersection O, Since the shape of the wing body support plates 2a and 2b is formed in a simple straight line by parallel translation to the radial line RL, it is manufactured even for a spacer type turbine nozzle or a side war type turbine nozzle. Or the assembly work to a diaphragm outer ring and an inner ring can be easily performed.

  That is, in this embodiment, when the blade body 1 having the flat blade body support plates 2a and 2b is applied to a spacer type turbine nozzle, the blade body support plates 2a and 2b are formed in a simple linear shape. Therefore, it can be inserted quickly and easily into the spacers of the diaphragm outer ring and inner ring with little gap, and the throat area and blade pitch between the blade body and the adjacent blade body can be rubbed together. Even without processing, the dimensions and positions as designed can be maintained.

  Further, in the present embodiment, the shape of the blade body support plates 2a and 2b is formed in a simple linear shape. Therefore, when applied to a sidewall type turbine nozzle, both ends of the blade body 1 and the blade body support plate 2a are used. , 2b, the radius of curvature of the connecting portion (base portion) is further reduced, so that the disturbance of the working fluid flowing through the wall surface of the sidewall can be reduced, and the adjacent blade body from the ventral side 4 of the blade body. The blade flow efficiency can be improved by reducing the secondary flow vortex based on the secondary flow flowing toward the back side 5 of the blade.

The conceptual diagram which shows the turbine nozzle which concerns on this invention. The partial notch conceptual diagram which shows the shape of the wing | blade main body support plate provided in the turbine nozzle which concerns on this invention. The conceptual diagram which shows the conventional turbine nozzle. The conceptual diagram which shows the spacer type of the conventional turbine nozzle. The conceptual diagram which shows the sidewall type of the conventional turbine nozzle. The conceptual perspective view seen from the rear edge side of the conventional turbine nozzle. The conceptual diagram seen from the AA arrow direction of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Blade body 2 Front edge 2a, 2b Blade body support plate 3 Rear edge 4 Abdomen side 5 Back side 10 Blade body 11 Diaphragm outer ring 12 Diaphragm inner ring 13 Welded part 14a, 14b Spacer 15a, 15b Nozzle blade body hole 16a, 16b Side Wall 17 wing back side

Claims (6)

A front edge facing the inflow side of the working fluid, a rear edge located on the outlet side of the working fluid, and connecting the front edge and the rear edge with two contour lines, and forming a ventral side and the other contour formed by one contour line A turbine nozzle having a blade body composed of a back side formed by a wire, comprising a blade body support plate on each of a blade outer diameter side and a blade inner diameter side of the blade body. The blade body support plate provided on the blade outer diameter side of the blade body has a horizontal plane passing through the intersection of the radial line and the contour line of the trailing edge as a reference plane, and both end surfaces of the reference plane are extended from the intersection, The turbine nozzle according to claim 1, wherein the turbine nozzle is configured to be parallel to the radial line. The blade body support plate provided on the blade inner diameter side of the blade body has a horizontal plane passing through the intersection of the radial line and the contour of the trailing edge as a reference plane, and both end surfaces of the reference plane extend from the intersection, and The turbine nozzle according to claim 1, wherein the turbine nozzle is configured to be moved parallel to the radial line. The turbine nozzle according to claim 2, wherein the blade body support plate is a flat plate. The turbine nozzle according to claim 1, wherein the blade body is a spacer insertion type. The turbine nozzle according to claim 1, wherein the blade body is a sidewall type.

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