JPH01187303A - Turbine nozzle - Google Patents

Abstract

PURPOSE:To prevent any fault by thermal stress, by constructing a turbine nozzle comprising an outer/inner annular supporting plates fixed to a turbine main body, a nozzle blade and the like, and making the construction for tapered fitting and assembling the inner ring of each nozzle blade to an outer annular supporting plate under the energizing of a spring. CONSTITUTION:A turbine nozzle is composed of a nozzle blade part 40 consisting of an outer ring 10, an inner ring 11, and a nozzle blade 12, an outer ring supporting plate 13, an inner ring supporting plate 14, and a retainer plate 15 and attached to a turbine main body. In this occasion, in the nozzle blade part 40, its inner ring 11 is energized in the downstream direction by a spring 18, and its tapered inner circumference surface 36 is brought in contact with the tapered outer circumference surface of the outer annular supporting plate 13, while convex parts 34 are respectively assembled by engaging with recessed parts 33. And also, the outer annular supporting plate 13 is combined with the inner annular supporting plate 14 by engaging the plurality of a radial direction convex part 32 formed on its inner circumference, with the recessed parts, facing the convex parts 32, the outer circumference surface of inner annular supporting plate 14.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a turbine nozzle used in gas turbines, steam turbines, etc.

(Prior Art) FIG. 5 is a sectional view showing a turbine nozzle portion of a conventional gas turbine. In the figure, 1 is a turbine shroud, 2 is a hub, 3 is a bolt for fixing the hub 2 to the turbine body 5, 4 is a nozzle blade made of a heat-resistant alloy that is cast by integrating the turbine shroud 1 and the hub 2, and 6 is the compressor turbine.

In such a gas turbine, high-temperature, high-pressure gas sent from a combustor (not shown) is accelerated by the nozzle blades 4 of the turbine nozzle, causing the compressor turbine 6 to rotate at high speed.

(Problems to be solved by the invention) By the way, in the conventional gas turbine turbine nozzle,
Heat-resistant alloys are used as the constituent material of the nozzle blades 4, which are exposed to the highest temperatures, so that they can withstand high-temperature gases, thereby improving turbine output. however,
Satisfactory high output could not be obtained at the temperature level that heat-resistant alloys can withstand. Further, since the nozzle blade 4 is integrally attached, when exposed to drought, abnormal internal stress is applied to the nozzle blade and its surrounding area due to thermal stress, which may cause problems such as cracks.

This invention was made in view of the above points, and can significantly improve turbine output compared to conventional turbine nozzles in which the nozzle blade is made of a heat-resistant alloy.
Another object of the present invention is to obtain a turbine nozzle that can prevent problems caused by thermal response.

(Means for Solving the Problems) This invention provides a turbine nozzle that includes an inner annular support plate fixed to a turbine body, an outer annular support plate attached to the inner annular support plate, and a downstream part of a separate annular support plate. A presser plate fixed to the turbine body from the side, a Hiramic inner ring and a ceramic outer ring attached to the outer periphery of the outer annular support plate, and a plurality of plates evenly attached with a predetermined gap between the inner ring and the outer ring. and a nozzle vane section consisting of nozzle blades, and the joint surface between the inner circumferential surface of the inner ring and the outer circumferential surface of the outer annular support plate is such that the inner diameter of the outer circumferential surface increases from upstream to downstream. That taper angle is 1! ! The inner ring has a tapered shape larger than m square, and a plurality of convex portions or concave portions are provided evenly on the downstream end side of the inner ring with a predetermined gap between the concave portions or convex portions provided on the outer periphery of the outer annular support plate, respectively. The outer annular support plate is fitted onto the outer circumference of the outer annular support plate by a spring attached to the turbine body and biased in the downstream direction so that the outer annular support plate is fitted with a predetermined gap on its inner circumference. A plurality of convex portions or four portions provided evenly with each other are fitted into concave portions or convex portions provided on the outer periphery of the inner annular support plate, so that the inner annular support plate is non-rotatably attached to the inner annular support plate. be.

(Function) Since the inner and outer rings of the four nozzle parts are made of ceramic, they can withstand higher temperatures than conventional turbine nozzles whose nozzle blades are made of heat-resistant alloy. Further, since the inner ring is tapered fitted to the outer annular support plate and is slidable in the axial direction, thermal stress generated in the nozzle blade portion is avoided at the tapered fitting portion. Also,
The nozzle wing portion and the outer annular support plate are mutually positioned by being biased by a spring and fitted in a tapered manner, and the outer annular support plate and the inner annular support plate have a protrusion and a recess provided in each other. They are mutually positioned by the fitting of the two and the function of the holding plate.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view showing a turbine nozzle according to an embodiment of the present invention, and FIGS. 2, 3, and 4 are perspective views showing the appearance of each component of the turbine nozzle of this embodiment. 2
The figure shows a nozzle wing and part of the outer annular support plate, FIG. 3 shows the outer annular support plate, and FIG. 4 shows the inner annular support plate. In FIG. 1, the turbine nozzle includes an outer ring 10 and an inner ring 11.
, and a nozzle wing section 40 consisting of the nozzle blade 12;
It is composed of an outer annular support plate 13, an inner annular support plate 14, and a presser plate 15, and is attached to the turbine body. 16 is a bolt for attaching the inner annular support plate 14 to the housing 17 together with the presser plate 15; 18 is a spring attached to the housing 17 together with the inner annular support plate 14 by the bolt 16; 19 is a scroll support plate; and 20 is a scroll support plate 19. 21 is an air chamber, 2 is a hole formed in
2 is a turbine blade, and 23 is a casing.

The inner annular support plate 14 is made of metal, and as shown in FIG.
A plurality of radial recesses 30 (four in this case) are formed evenly on the outer peripheral surface with a predetermined gap.

The outer annular support plate 13 is made of ceramic, and as shown in FIG.
A plurality of radial convex portions 32 are formed on the outer periphery F so as to fit into each of the two radial convex portions 32, and a plurality of radial concave portions 33 are formed evenly on the outer periphery F with a predetermined gap. Further, the outer circumferential surface 35 has a tapered shape in which the inner diameter increases from upstream to downstream, and the taper angle is larger than the friction angle. Furthermore, the thickness of the inner peripheral portion where the convex portion 32 is provided is the same as that of the inner annular support plate 1.
It is thicker than 4.

The inner ring 11 and outer ring 10 that constitute the nozzle wing portion 40 are made of ceramic. Further, as shown in FIG. 2, the inner circumferential surface 36 of the inner ring 11 has a tapered shape so as to join to the tapered outer circumferential surface 35 of the outer annular support plate 13.
On the downstream end side of the inner ring 11, there is a recess 3 of the outer annular support plate 13.
Axial convex portions 34 are formed to fit into the respective portions 3 and 3.

Further, a plurality of nozzle blades 12 are evenly attached between the inner ring 11 and the outer ring 10 with a predetermined distance gI.

The spring 18 is made of metal and is cooled by cooling air from an air chamber 21 guided into a hole 20 of the scroll support plate 19.

In the nozzle wing section 40, the inner ring 11 is urged downstream by the spring 18, and the tapered inner circumferential surface 36 is joined to the tapered outer circumferential surface 35 of the outer annular support plate 13. are fitted into the recesses 33, that is, tapered, and attached to the outer annular support plate 13, and the outer annular support plate 13 has a protrusion 32 that is fitted into the recess 30, respectively.
The inner annular support plate 14 is fitted and fixed to the housing 17 together with the presser plate 15 by bolts 16 . Here, the presser plate 15 is a disk having an inner diameter larger than the inner diameter of the inner annular support plate 14 so as to be able to press the inner peripheral portion of the outer annular support plate 13 in the downstream direction together with the inner annular support plate 14.
Since the thickness of the inner peripheral portion of the outer annular support plate 13 is thinner than the thickness of the inner annular support plate 14, the outer annular support plate 1
3, the presser force from the presser plate 15 is not directly applied.

In the turbine nozzle of this embodiment, the inner ring 11 and outer ring 10 that make up the nozzle blade section 40 are made of ceramic, so they are more resistant to high-temperature gas than conventional turbine nozzles in which the nozzle blades are made of a heat-resistant alloy. It is possible to improve turbine output and thermal efficiency. In addition, the inner ring 11 has a spring 18 attached to the outer annular support plate 13.
Since the nozzle blades 40 are biased and tapered fitted and are slidable in the axial direction, thermal stress caused when the nozzle blades 40 are exposed to high temperatures can be released. Also, inner ring 11
is attached to the outer annular support plate 13 with the convex part 34 fitted into the concave part 33 under pressure from the spring 18, and although it is slidable in the axial direction, rotation is not possible. , is positioned relative to the outer annular support plate 13, and the outer annular support plate 13 does not directly receive the pressing force from the presser plate 15, but due to the urging force of the spring 18 and the thrust force acting on the nozzle wing portion 40. The convex portion 32 is pressed against the presser plate 15.
is fitted into the recess 30 and cannot rotate, so it is positioned relative to the inner annular support &14. Moreover, in this embodiment, since the outer annular support plate 13 is made of ceramic, the difference in thermal expansion with the inner ring 11 can be reduced, and the generation of thermal stress can be reduced. Furthermore, when positioning the outer annular support plate 13 made of fragile ceramic, the pressing force from the presser plate 15 is prevented from directly acting on the outer annular support plate 13, so that the outer annular support plate 13 can be easily moved. You can prevent it from breaking. Furthermore, since the spring 18 is cooled by the cooling air from the hole 20, it is possible to prevent the biasing force of the spring 18 from changing due to heat.

In the above embodiment, the outer annular support plate 13 is made of ceramic, but it may also be made of metal.

Further, in the above embodiment, the inner ring 11 is provided with the protrusion 34 and the outer annular support plate 13 is provided with the recess 33, and the two are fitted together. The same applies to the convex portion 32 of the support plate 13 and the concave portion 30 of the inner annular support plate 14. Furthermore, the axial and radial directions of the convex portions 32.34 and the concave portions 30.33 are not limited to these.

(Effect of the invention) As described above, according to the present invention, the inner ring 11 made of Leramitsu
, a nozzle wing section 40 consisting of a ceramic outer ring 10 and a nozzle blade 12, and an outer annular support plate 13 in which the inner ring 11 is biased by a spring 18 and its inner circumferential surface is joined to the outer circumferential surface to be tapered fitted. , an inner annular support plate 14 in which a protrusion 32 on the inner periphery of the outer annular support plate 13 is fitted into a recess 30 on the outer periphery; and a presser plate 15 fixed to the turbine body from the downstream side of the separate annular support plate. Since the turbine nozzle is configured by the above structure, each component can be positioned relative to each other by taper fitting, fitting of protrusions and recesses, and the function of the holding plate 15, and the nozzle blade is made of a heat-resistant alloy. Compared to conventional turbine nozzles, the turbine output and thermal efficiency can be further improved, and thermal stress can be avoided to prevent problems caused by thermal stress.

In addition, since the outer annular support plate 13 is made of ceramic, the difference in thermal expansion with the inner ring 11 can be reduced to reduce the occurrence of thermal stress, and the thickness of the inner peripheral portion where the convex portion 32 is provided can be reduced. Since it is made thinner than the thickness of the inner annular support plate 14, the presser h of the presser plate 15 can be prevented from being applied directly during positioning, and the outer annular support plate 13 made of fragile ceramic can be prevented from being easily broken. be able to.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a turbine nozzle according to an embodiment of the present invention, and FIG. 2 is a perspective view showing the external appearance of a part of the nozzle blade and the outer annular support plate of the turbine nozzle of this embodiment.
FIG. 3 is a perspective view showing the appearance of the outer annular support plate of the turbine nozzle of this embodiment, FIG. 4 is a perspective view showing the appearance of the inner annular support plate of the turbine nozzle of this embodiment, and FIG. It is a sectional view showing a turbine nozzle. 10...outer ring,
11... Inner ring, 12... Nozzle blade, 13...
・Outer annular support plate, 14...Inner annular support plate, 15・
... Holding plate, 16... Bolt, 17... Housing, 18... Spring, 19... Scroll support plate, 20
... hole, 21 ... air chamber, 30.33 ... recess,
31...Bolt hole, 32.34...Protrusion, 35...
- Outer circumferential surface, 36... Inner circumferential surface, 40... Nozzle wing section. Patent applicant Yanmar Diesel Co., Ltd. Figure 1 Figure 2 Figure 3 Figure 4

Claims (2)

[Claims] (1) An inner annular support plate fixed to the turbine body, an outer annular support plate attached to the inner annular support plate, a presser plate fixed to the turbine body from the downstream side of both annular support plates, and the outer side A ceramic inner ring and a ceramic outer ring are attached to the outer periphery of an annular support plate, and a nozzle wing section is made up of a plurality of nozzle blades that are evenly attached with a predetermined gap between the inner ring and the outer ring. The turbine nozzle includes a joint surface between the inner peripheral surface of the inner ring and the outer peripheral surface of the outer annular support plate, wherein the inner diameter of the outer peripheral surface increases from upstream to downstream and the taper angle is larger than the friction angle. The inner ring has a tapered shape, and a plurality of convex portions or concave portions provided evenly with a predetermined gap on the downstream end side of the inner ring are respectively fitted into concave portions or convex portions provided on the outer periphery of the outer annular support plate. and is biased in the downstream direction by a spring attached to the turbine body to be mounted on the outer periphery of the outer annular support plate in a non-rotatable manner, and the outer annular support plate is
A plurality of convex portions or concave portions provided evenly on the inner circumference with a predetermined gap are fitted into concave portions or convex portions provided on the outer circumference of the inner annular support plate, respectively, and the inner annular support plate is rotated. A turbine nozzle characterized in that it is installed in a manner that is impossible to install. (2) the outer annular support plate is made of ceramic;
2. The turbine nozzle according to claim 1, wherein the thickness of the inner peripheral portion provided with the convex portion or the concave portion is thinner than the thickness of the inner annular support plate.