JPS61232301A - Rotary vanes of axial flow turbine - Google Patents

Abstract

PURPOSE:To allow the securing of a prescribed outflow Mach level by forming the peripheral part of rotary vanes in the shape of wings with small curvature at their rear end part and deciding an angle formed by almost flat intrados and the periphery at that point appropriately in relation to non-dimensional peripheral speed. CONSTITUTION:In an axial flow turbine with rows of rotary vanes 1, 2 which are revolving at transonic speed, the back surface 8 and the intrados 7 of the vane surface at its rear end part 6 are formed to be almost flat at an outer peripheral part in the radial direction where the channels for the rows 1 and 2 of the rotary vanes form the transonic flow of the rotary vanes shaping tapering passages between the front end part 5 and the rear end part 6 of rotary vanes 1, 2. The intrados outlet angle rP is set to be smaller than the straight line connecting a point with the non- dimensional peripheral speed of 0.9 and rP of 41 degrees and another point with the non-dimensional peripheral speed of 0.9 and rP of 31 degrees in relation to non- dimensional peripheral speed for respective stage surfaces for the peripheral part in the radial direction for transonic flows. It is also set to be larger than a straight line connecting between a point with non-dimensional peripheral speed of 0.9 and rP of 31 degrees and another point with the non-dimensional peripheral speed of 1.54 and rP of 10 degrees.

Description

【発明の詳細な説明】 〔発明の利用分野〕 本発明は、高速回転の長翼用の軸流蒸気タービン回転羽
根に係り、タービンの円周方向に隣接する回転羽根間の
翼列流路を流れる気体の速度を亜音速から超音速に効率
よく遷移させ規定の流出マツハａｆ得、かつ流出マツハ
数の低下時のタービン効率の低下を抑制するために好適
な軸流タービンの回転羽根に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an axial flow steam turbine rotor blade for long blades rotating at high speed. The present invention relates to a rotary blade of an axial flow turbine suitable for efficiently transitioning the speed of flowing gas from subsonic to supersonic, obtaining a specified outflow speed, and suppressing a decrease in turbine efficiency when the outflow speed decreases.

〔発明の背景〕[Background of the invention]

この回転羽根では、主として最終段回転羽根の半径方向
外側先端部における流体の流れの状態が音速を超えてい
る。この回転羽根は蒸気が音速より低い速度で入り、超
音速で出るから遷音速回転羽根と呼ばれている。従来、
この遷音速回転羽根翼形として、米国特許３，３３３，
８１７号及び特開昭５６−１２６８１号公報に記載され
ているような翼形があった。これらの翼形は翼列流路の
最狭部Ｃスロート）以降で末広流路を形成し、設計流出
マツハ数に対して回転羽根の間を流動する流体の速度を
亜音速から超音速に効率よく遷移させることができる。In this rotating blade, the fluid flow state mainly at the radially outer tip of the final stage rotating blade exceeds the speed of sound. These rotating blades are called transonic rotating blades because steam enters at a speed lower than the speed of sound and exits at supersonic speed. Conventionally,
As this transonic rotating blade airfoil, U.S. Patent No. 3,333,
There were airfoil shapes as described in No. 817 and Japanese Unexamined Patent Publication No. 12681/1983. These airfoil shapes form a widening flow path after the narrowest part of the blade row flow path (C throat), and effectively increase the speed of the fluid flowing between the rotary blades from subsonic to supersonic for the design outflow Matsuha number. It can be transitioned well.

しかし、設計マツハ数以外、特に設計マツハ数より低い
流出マツハ数になると、不足膨張のｔめ境界層が厚くな
り翼形損失が大きくなる。一方、比較的低マツハ数の遷
音速流ではスロート以降の翼形背面を直線としたストレ
ート・パック翼形が良好な性能を示すことが知られてい
る。However, if the outflow Matsuha number is other than the design Matsuha number, especially lower than the design Matsuha number, the under-expanded boundary layer will become thicker and the airfoil shape loss will increase. On the other hand, it is known that a straight-pack airfoil with a straight airfoil back surface after the throat exhibits good performance in transonic flow with a relatively low Matsuha number.

しかし、前記しり翼形のように、亜音速から超音速へ遷
移させる九めに空気力学的な中細流路を形成しておらず
、しばしば設計マツ・・数を高くできなく、翼形損失が
急増することがあった。However, like the above-mentioned tail airfoil, it does not form an aerodynamic narrow flow path at the ninth point to transition from subsonic to supersonic speed, and often the design number cannot be increased, resulting in airfoil loss. There was a sudden increase.

近年、大容量原子力発電プラントの開発が進む反面、中
小容量の火力発電プラントは部分負荷で運転される機会
が多く、最終段長翼の流出マツハ数も定格運転時のマツ
ハ数より低いマツハ数で作動する時間が多くなってきて
おりこの低いマツハ数での翼形損失も小さくする必要が
ある。In recent years, while the development of large-capacity nuclear power plants has progressed, small- to medium-sized thermal power plants are often operated at partial load, and the outflow Matsuha number of the final stage long blade is also lower than the Matsuha number during rated operation. As the time is increasing, it is necessary to reduce the airfoil loss at this low Matsuha number.

〔発明の目的〕[Purpose of the invention]

本発明の目的は、前記従来技術の問題を解決し、翼列流
路を流れる流れる流体の速度を亜音速から超音速に効率
よく遷移させ規定の流出マツノ・数を得ることができ、
かつ設計流出マツノ・数よりも低い流出マツハ数での運
動エネルギー損失を低減させ得る軸流タービン回転羽根
を提供することにある。An object of the present invention is to solve the problems of the prior art, to efficiently transition the velocity of the flowing fluid flowing through the blade row flow path from subsonic to supersonic, and to obtain a specified number of outflows.
Another object of the present invention is to provide an axial flow turbine rotating blade that can reduce kinetic energy loss at an outflow number lower than a design outflow number.

〔発明の概要〕[Summary of the invention]

本発明の要旨とするところは、回転羽根の外周部分がス
トレートパック翼形またはこれに準する翼形後端部分の
曲率が小さい翼形で形成され、翼形後端部分のほぼ平な
腹面て周方向とでなす腹面出口角を、半径方向の各段面
の周速を音速で無次元化した無次元周速に対して適正に
決定することにより、後縁からの膨張波により隣接する
回転羽根の後縁背面が設計流出マツハ数になるようにし
たものである。The gist of the present invention is that the outer peripheral portion of the rotary blade is formed in a straight pack airfoil shape or a similar airfoil shape with a small curvature at the rear end portion of the airfoil, and the substantially flat ventral surface of the rear end portion of the airfoil shape is formed. By properly determining the exit angle of the ventral surface with respect to the circumferential direction with respect to the dimensionless circumferential velocity obtained by making the circumferential velocity of each step surface in the radial direction nondimensional with the speed of sound, the expansion wave from the trailing edge prevents adjacent rotation. The rear surface of the trailing edge of the blade is designed to have a design outflow number.

〔発明の実施例〕[Embodiments of the invention]

以下、本発明の一実施例を図面により詳しく説明する。 Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

第１図は、隣り合つ穴２個の回転羽根１及び２ｔ−回転
羽根先端近くで切断したところを示す断面図である。こ
の切断し食断面の形ｔ−ｇ形と呼び、翼形は半径方向内
側に向って形及び向きも変つそ行く。各翼形には蒸気の
流入側である前縁３及び流出側でおる後縁４がおり、−
また矢印で示し九回転羽根の回転方向の面である背面８
と、これと反対側の面である腹面７がある。図面の回転
羽根２に示し友ように前縁側の部分を前端部分５、後縁
側の部分を後端部６と定義ずける。また、第２図に示す
ように後端部分６の腹面７と周方向でなす角度全腹面出
口角度γＰと定義ずける。各回転羽根の前端部分５は、
隣接回転羽根の後端部分６に重って伸び、両羽根間に先
細ノズル部を形成する。FIG. 1 is a sectional view showing two adjacent holes of rotating blades 1 and 2t, taken near the tips of the rotating blades. The shape of this cut cross section is called the t-g shape, and the shape and direction of the airfoil change inward in the radial direction. Each airfoil has a leading edge 3 on the steam inflow side and a trailing edge 4 on the outflow side, -
Also, the back surface 8, which is the surface in the direction of rotation of the nine-rotation blade, is indicated by an arrow.
There is a ventral surface 7 which is the opposite surface. As shown in the rotating blade 2 of the drawing, the leading edge side portion is defined as the front end portion 5, and the trailing edge side portion is defined as the rear end portion 6. Further, as shown in FIG. 2, the angle formed by the ventral surface 7 of the rear end portion 6 in the circumferential direction is defined as the total ventral surface exit angle γP. The front end portion 5 of each rotating blade is
It extends over the rear end portion 6 of the adjacent rotary blade, forming a tapered nozzle portion between both blades.

第３図は、後端部分の蒸気の膨張特性を示す。FIG. 3 shows the expansion characteristics of steam in the rear end portion.

すなわち、先細流路のスロート０で蒸気流速は音速スな
わち”マツハ数＝１”となり、蒸気はスロートＯ以降で
さらに膨張する。ここで、腹面７側の後縁４では上記し
たようにマツハ数１に相当する圧力までしか膨張してい
ないが、後述するように背面圧力はさらに低くなってお
り、腹面７に沿って流れて来た蒸気は背面圧力まで急膨
張し背面８方向にνだけ転向する。この流れの転向角ν
は、膨張した時のマツハ数Ｍに対して、次式に示すプラ
ントル・マイヤー函数νの値となる。That is, at the throat 0 of the tapered channel, the steam flow velocity becomes the sonic velocity, that is, "Matsuha number = 1", and the steam further expands after the throat 0. Here, as mentioned above, the rear edge 4 on the ventral surface 7 side expands only to a pressure corresponding to Matsuha's number 1, but as will be described later, the pressure on the back surface is even lower, and it flows along the ventral surface 7. The coming steam expands rapidly up to the back pressure and is deflected by ν in 8 directions from the back. Turning angle of this flow ν
is the value of the Prandtl-Meyer function ν shown in the following equation for the Matsuh number M when expanded.

・・・・・・・・・（１） ここで、ｋは気体の断熱指数であり、νはラジアンで表
わした値である。しかし一般的にはラジアンを度に変換
して度で表わすことが多く、以下では度として取扱うこ
とにする。(1) Here, k is the adiabatic index of the gas, and ν is a value expressed in radians. However, in general, radians are often converted to degrees and expressed in degrees, and below we will treat them as degrees.

このように、後縁４で腹面７側の蒸気が急膨張すると扇
状の膨張波が発生し、破線で示すマツハ線９ができる。In this way, when the steam on the ventral surface 7 side expands rapidly at the trailing edge 4, a fan-shaped expansion wave is generated, forming a Matsuha line 9 shown by a broken line.

マツハ線上では、反射波ない単一波の領域では流れは一
様、すなわちマツハ数や流れの方向も等しくなるが、反
射波が干渉する領域は特性曲線法で取扱う必要がある。On the Matsuha line, in the area of a single wave with no reflected waves, the flow is uniform, that is, the Matsuha number and direction of flow are the same, but areas where reflected waves interfere must be treated using the characteristic curve method.

しかし、高マツハ数のマツハ線９ｈは低マツハ数の反射
波の影響は小さく近似的に単一波、すなわち直線と見な
すことができる。However, the Matsuhah line 9h with a high Matsuhah number is less affected by the reflected waves of a low Matsuhah number and can be approximately regarded as a single wave, that is, a straight line.

また、腹面７側の流れと背面８側の流れが衝突して互に
流れが圧縮されて衝撃波１０Ｌ及びＩｏｎが発生する。Further, the flow on the ventral surface 7 side and the flow on the rear surface 8 side collide, and the flows are mutually compressed to generate shock waves 10L and Ion.

そして衝撃波後の気体の流れ角は腹側の流れと背側の流
れが衝突す前の流れ角の平均値とみなすことができる。The gas flow angle after the shock wave can be regarded as the average value of the flow angles before the ventral flow and dorsal flow collide.

本発明では、隣接翼の後縁端に達する高マツハ数のマツ
凸線９ｈのマツハ数の値を設計マツ／％数になるように
するものである。In the present invention, the value of the pine convex line 9h having a high pine convex number reaching the trailing edge of the adjacent blade is made to be the design pine/% number.

次に、第２図はタービン回転羽根の後端部の設計法を示
す。この図により、タービン回転羽根の設計法すなわち
隣接翼の後縁に達するマツ・・線を設計マツハ数にする
方法について述べる。Next, FIG. 2 shows a design method for the rear end portion of the turbine rotating blade. Using this figure, we will discuss how to design a turbine rotor blade, that is, how to set the design Matsuha number to the Matsuha line that reaches the trailing edge of the adjacent blade.

タービン回転羽根の後縁４のエツジ厚さδは０．８〜１
．２　ｍ程度になり、この場合後縁４の直後の場所１２
の圧力Ｐｇは翼列後流の圧力Ｐ−より低くなることが知
られている。第４図はこの場合の実験結果の１例であり
、横軸は翼列後流の圧力Ｐと翼列入口全圧の比であり、
縦軸は後縁４の直後の場所１２の圧力Ｐａと翼列入口全
圧との比である。このようにＰＲの圧力がＰ−より低く
なると後縁部で局所的にマツノ・数が大きくなる。その
マツハ数ＭＢと翼列後流のマツノ・数Ｍを比較したのが
第５図であり、後縁部での局所マツノ・数Ｍｍが翼列後
流のマツＩ・数Ｍより約０．２大きくなる。The edge thickness δ of the trailing edge 4 of the turbine rotating blade is 0.8 to 1
．． 2 m, and in this case, the location 12 immediately after the trailing edge 4
It is known that the pressure Pg is lower than the pressure P- downstream of the blade row. Figure 4 shows an example of experimental results in this case, where the horizontal axis is the ratio of the pressure P behind the blade row to the total pressure at the blade row inlet.
The vertical axis is the ratio between the pressure Pa at a location 12 immediately behind the trailing edge 4 and the total pressure at the inlet of the blade. In this way, when the pressure of PR becomes lower than P-, the number of matsuno becomes larger locally at the trailing edge. Figure 5 shows a comparison of the Matsuno number MB and the Matsuno number M downstream of the blade row, where the local Matsuno number Mm at the trailing edge is approximately 0. 2 It gets bigger.

し友がって、第２図に示すように腹面７側の蒸気は後縁
４で前記局所マツ・・数Ｍｍに対するプラントルマイヤ
ー函数ν３だけ転向する。Therefore, as shown in FIG. 2, the steam on the ventral surface 7 side is deflected at the trailing edge 4 by a Prandtlmeyer function ν3 for the local pine, several Mm.

次に、設計マツノ・数に対するマツノ・線の角度は腹面
７側の流体が後縁で転向した流れ方向１１に対して、次
式のマツＩ・角μの方向となる。Next, the angle of the Matsuno line with respect to the designed Matsuno line is in the direction of the Matsuno angle μ of the following equation with respect to the flow direction 11 in which the fluid on the ventral surface 7 side is turned at the trailing edge.

この結果、第２図から明らかなように、隣接回転羽根の
後縁に達すマツＩ・線のマツノ・角μとプラントル・マ
イヤー函数νＢと腹面出口角γＰとの間には次式の関係
が成立つ。As a result, as is clear from Fig. 2, there is a relationship between the Matsuno angle μ of the Matsu I line reaching the trailing edge of the adjacent rotating blade, the Prandtl-Meyer function νB, and the ventral exit angle γP. Established.

γＰ＝μ−シＢ　　　　　　　　　・・・・・・・・・
（８）従って、腹面出口角γＰは設計マツ・・数に対し
て（３）式で求められる値より小さい値に設計しないと
、翼列出口圧力をいくら低くしても翼列流路出口の圧力
は低下せず、翼列出口で規定の流出マツハ数を得ること
ができない。γP=μ−shiB ・・・・・・・・・
(8) Therefore, if the ventral exit angle γP is not designed to be smaller than the value obtained by equation (3) for the design number, no matter how low the blade cascade outlet pressure is, the blade cascade flow path exit The pressure does not drop and the specified outflow Matsuha number cannot be obtained at the exit of the blade row.

一方、腹面７側の流れと背面８側の流れが衝突して、衝
撃波が発生した後の流体の流れ角は、後縁４の後では同
じマツハ数の流れが衝突するので、衝突後は腹面７側の
転向後の流れ方向１１と腹面８側の転向後の流れ方向１
３との平均と見なすことができる。ここで、腹面側の流
れ方向１１はν！ｌ　＋　ｒ　ｐであり、背面側の流れ
方向１３は背面出口角γＢから設計マツＩ・数Ｍと前記
の局所マツハ数ＭＢのプラントル・マイヤー函数の差で
求められ、γＢ−（ν藤−ν）となる。ゆえに、衝突後
の流体の流れ角αは となる。On the other hand, the flow angle of the fluid after the flow on the ventral surface 7 side collides with the flow on the back surface 8 side and a shock wave is generated is that the flow angle of the fluid after the collision is that the flows with the same Matsuha number collide after the trailing edge 4. Flow direction 11 after turning on side 7 and flow direction 1 after turning on ventral side 8
It can be considered as an average of 3. Here, the flow direction 11 on the ventral side is ν! l + r p, and the flow direction 13 on the back side is determined from the back exit angle γB by the difference between the Prandtl-Meier function of the design Matsuha number M and the local Matsuha number MB, and γB-(νFu-ν ). Therefore, the flow angle α of the fluid after the collision becomes.

第６図は、回転羽根出口の速度三角形であり、■が回転
羽根出口の相対速度、Ｕが絶対速度、Ｗが周速である。FIG. 6 shows a velocity triangle at the rotary vane outlet, where ■ is the relative velocity at the rotary vane outlet, U is the absolute velocity, and W is the circumferential velocity.

最終段回転羽根では、同一流量を流した時、流出蒸気の
持去る運動エネルギーを最小にするために、絶対速度Ｕ
は通常図のように軸方向に流れるように設計される。ま
友αが（４）式で与えられる翼列後の流れ角である。In the final stage rotary vane, when the same flow rate flows, the absolute speed U is
is usually designed to flow in the axial direction as shown in the figure. The angle α is the flow angle after the blade row given by equation (4).

前記したように、腹面出口角ｒｐは規定の流出マツ・・
数を得るためには、一定値より小さくする必要があるが
、反面（４）式から明らかなようにあまり小さくすると
流出角が小さくなり設計流量が流れなくなる。絶対速度
Ｕは軸流タービンの回転羽根を流れる流量に比例する値
であり、通常の軸流タービンでは音速ａで無次元化した
見で０．５以上で用いられる。また、腹面出口角γＰと
背面出口角γ８の差で示される後縁角εは、回転羽根の
強度から通常４°以上に設計される。この見＝　Ｏ，Ｓ
、ε＝４°を下限条件とすると、その時の設計マツハ数
に対して流出角αが速度三角形の関係より決まり背面出
口角を（４）式より求めることができる。・第７図は、
設計マツハ数Ｍに対して、乾き飽和蒸気１　ｋ　＝　１
．１３５　’Ｉについて（３）式より求めた上限の腹面
出口角１４と、前記下限条件により（４）式より求めた
下限の腹面出口角１５の値である。設計流出マツ・・数
Ｍに対して斜線で示した範囲が本発明の使用範囲となる
。この結果、本発明による回転羽根の最大設計マツハ数
は１．６２となる。As mentioned above, the ventral exit angle rp is the specified outflow pine...
In order to obtain this value, it is necessary to make it smaller than a certain value, but on the other hand, as is clear from equation (4), if it is made too small, the outflow angle will become small and the designed flow rate will not flow. The absolute speed U is a value proportional to the flow rate flowing through the rotary blades of an axial flow turbine, and in a normal axial flow turbine, it is used at a value of 0.5 or more when dimensionless with the sonic speed a. Further, the trailing edge angle ε, which is represented by the difference between the ventral exit angle γP and the rear exit angle γ8, is usually designed to be 4° or more in view of the strength of the rotary blade. This view = O, S
, ε=4° as the lower limit condition, the outflow angle α is determined from the relationship of the velocity triangle with respect to the design Matsuha number at that time, and the back exit angle can be determined from equation (4).・Figure 7 is
For the design Matsuha number M, dry saturated steam 1 k = 1
．． 135'I are the values of the upper limit ventral surface exit angle 14 obtained from equation (3) and the lower limit ventral surface exit angle 15 obtained from equation (4) based on the lower limit condition. Design outflow pine...The range indicated by diagonal lines with respect to the number M is the usable range of the present invention. As a result, the maximum design Matsuha number of the rotating blade according to the present invention is 1.62.

第８図は、第７図に示した限界腹面出口角γＰの時、各
流出マツハ数における（４）式より求まる流出角αと、
第６図に示した速度三角形より定まる流出角αを等しく
するように求めｔ無次元周速Ｗと限界腹面出口角の関係
を示す。すなわち、無次元周速Ｗは次式により決定され
る。FIG. 8 shows the outflow angle α found from equation (4) at each outflow Matsuha number when the limit ventral exit angle γP shown in FIG.
The outflow angle α determined from the velocity triangle shown in FIG. 6 is determined to be equal, and the relationship between the dimensionless circumferential speed W and the critical ventral surface exit angle is shown. That is, the dimensionless circumferential speed W is determined by the following equation.

　　ｖ −＝　−ｃｏｓα＝ＭＣＯ８α　　　　　　　・・印・
…（５）　　　ａ この結果、無次元周速が犬きくなると腹面出口角は小さ
くなり、規定の設計マツハ数を得るための上限値も１６
、規定の流量を流すｔめの下限値１７も無次元周速に対
してほぼ直線的に変化する。v −= −cosα=MCO8α ・・mark・
...(5) a As a result, when the non-dimensional circumferential speed becomes steeper, the ventral exit angle becomes smaller, and the upper limit for obtaining the specified design Matsuha number is also 16.
, the lower limit value 17 for the tth point at which the specified flow rate is allowed to flow also changes almost linearly with respect to the dimensionless circumferential speed.

したがって、本発明による回転羽根の腹面出口角ｒ、は
遷音速流で流出する半径方向外周部の各段面の無次元周
速に対して、無次元周速が０．９で腹面出口角が４１６
なる点と無次元周速が１．５８で腹面出口角が１０°な
る画点金納ぶ直線より小さく、無次元周速が０．９で腹
面出口角が３１°なる点と無次元周速が１．５４で腹面
出口角が１０°なる両点を結ぶ直線より大きい。ま比、
無次元周速は半径方向外側が大きく、内側になるに従っ
て小さくなるので、腹面出口角γＰは回転羽根の先端部
から根元部に向ってほぼ直線的に大きくなる。Therefore, the ventral surface exit angle r of the rotary vane according to the present invention is calculated as follows: 416
The point where the non-dimensional peripheral speed is 1.58 and the ventral exit angle is 10° is smaller than the straight line, and the point where the non-dimensional peripheral speed is 0.9 and the ventral exit angle is 31° and the non-dimensional peripheral speed is 1.54, which is larger than the straight line connecting both points where the ventral exit angle is 10°. Ma ratio,
Since the dimensionless circumferential speed is large on the outer side in the radial direction and becomes smaller on the inner side, the ventral surface exit angle γP increases almost linearly from the tip to the root of the rotary blade.

なお、すが０．６〜０．７の設計を行う場合、上限マツ
ハ数が次第に小さくなるので、先端部は上限の腹面出口
角として、途中からり＝一定の回転羽根を作る場合もあ
る。In addition, when designing with a diameter of 0.6 to 0.7, the upper limit Matsuha number gradually becomes smaller, so the tip part may be set to the upper limit ventral surface exit angle, and a rotating blade with a constant rotation may be made in the middle.

第１０図は本発明による回転羽根の１段面の翼形の２次
元具列実験による運動エネルギー損失１８を、従来の先
細流路のストレート・パック翼形の損失１９の最小損失
ｔ−１としご比較して示しｔ値である。このように本発
明によれば、従来の先細流路の翼形のように設計マツハ
数で損失が急増することもなく、また中細ノズル形遷音
速翼形の損失２０のように設計マツハ数より低いマツハ
数に対しても良好な翼列性能を達成することができる。FIG. 10 shows the kinetic energy loss 18 in a two-dimensional array experiment of the airfoil shape of one stage of the rotary blade according to the present invention, and the minimum loss t-1 of the loss 19 of the conventional straight pack airfoil shape with a tapered channel. The t value is shown for comparison. As described above, according to the present invention, the loss does not increase rapidly with the design Matsuhashi number as in the case of the conventional airfoil with a tapered flow path, and the loss does not increase rapidly with the design Matsusha number, as in the case of the design Matsusha number of 20, as in the case of the medium-narrow nozzle type transonic airfoil. Good blade row performance can be achieved even for lower Matsuha numbers.

〔発明の効果〕〔Effect of the invention〕

本発明によれば、超音速で流出する翼列出口のマツハ数
を、膨張波であるマツハ線で設計流出マツハ数にするこ
とができる。また、先細流路を持つ翼であり、低マツハ
数でも良好な性能の回転羽根とすることができ、遷音速
流段落を持つ軸流蒸気タービンの効率向上、特に部分負
荷運転時の効率を大幅に向上できる効果がある。According to the present invention, the Matsuha number at the outlet of the blade row, which flows out at supersonic speed, can be made the design outflow Matsuha number by the Matsuha line, which is an expansion wave. In addition, since the blade has a tapered flow path, it can be used as a rotary blade with good performance even at a low Matsuha number, improving the efficiency of axial steam turbines with transonic flow stages, especially during partial load operation. It has the effect of improving

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は本発明における隣り合った２つの回転羽根の横
断面図、第２図は第１図後縁端部の拡大後の圧力の差を
示す実験値、第５図は同様のマツハ数の差を示す実験値
、第６図は回転羽根から流出する蒸気の速度三角形、第
７図は設計流出マツハ数に対する腹面出口角の範囲を示
す計算値、第８図は回転羽根の半径方向断面の周速を音
速で無次元し文無次元周速と腹面出口角の範囲を示す計
算値、第９図は先行技術による回転羽根と本発明による
回転羽根のエネルギー損失のマツハ数に対する特性を示
す。 １・・・回転羽根、２・・・回転羽根、３・・・前縁、
４・・・後縁、５・・・前端部分、６・・・後端部分、
７・・・腹面、８・・・背面、９・・・マツハ線、ｒｐ
・・・腹面出口角、０・・・スロート、ν・・・プラン
トル・マイヤー函数、μ・・・マツハ角、δ・・・エツ
ジ厚さ、１２・・・後縁直後部分、Ｐ−・・・翼列後流
圧力、Ｐｉ＋・・・後縁直後部分力、−Ｐｏｔ・・・翼
列入口全圧、ＭＩＩ・・・後縁直後の局所マツハ数、Ｍ
・・・設計マツハ数、Ｗ・・・周速、ａ・・・流体の’
１５＋　　国 第２−　聞 ￥１３　目 ＹＪ４−口 ￥、Ｓ　θ １−０　　　１．２　　　　１．４　　　　＋、ら　　
　　１，８Ｓ＊、出マ・７・←収ｈ ｌ・０　　　　　１．２−　　　　１−４　　　　１．
Ｌ歴、次″７Ｃ−１＄１速イ＾ ￥Ｊ９　口Fig. 1 is a cross-sectional view of two adjacent rotating blades in the present invention, Fig. 2 is an experimental value showing the difference in pressure after expansion of the trailing edge of Fig. 1, and Fig. 5 is a similar Matsuha number. Figure 6 shows the velocity triangle of the steam flowing out from the rotary vane, Figure 7 shows the calculated value showing the range of ventral exit angle for the design outflow Matsuha number, and Figure 8 shows the radial cross section of the rotary vane. Figure 9 shows the characteristics of energy loss versus Matsuha number for the rotary blade according to the prior art and the rotary blade according to the present invention. . 1... Rotating blade, 2... Rotating blade, 3... Leading edge,
4... Trailing edge, 5... Front end portion, 6... Rear end portion,
7... ventral surface, 8... dorsal surface, 9... Matsuha line, rp
... Ventral exit angle, 0... Throat, ν... Prandtl-Meyer function, μ... Matsuha angle, δ... Edge thickness, 12... Part immediately after the trailing edge, P-...・Blade cascade wake pressure, Pi+... partial force immediately after the trailing edge, -Pot... total pressure at the blade cascade inlet, MII... local Matsuha number immediately after the trailing edge, M
...Design Matsuha number, W...peripheral speed, a...fluid'
15+ Country 2nd - ¥13th YJ4-口¥, S θ 1-0 1.2 1.4 +, et al.
1,8S*, Output・7・←Collection h l・0 1.2- 1-4 1.
L history, next "7C-1$1 speed I^ ￥J9 mouth

Claims (1)

【特許請求の範囲】 １、遷音速状態で回転する回転羽根翼列を持つ軸流ター
ビンであつて、回転羽根翼列流路が回転羽根前端部分か
ら後端部分にかけて先細流路を形成する回転羽根の遷音
速流になつている半径方向外周部分において、後端部分
の翼面の背面及び腹面がほぼ平となつていて、該腹面と
周方向とでなす腹面出口角度を一方の座標軸に、回転羽
根の各断面の周速を音速で無次元化した無次元周速を他
の座標軸にとつた座標上で無次元周速に対して無次元周
速が０．９で腹面出口角度が４１°なる点と無次元周速
が１．５８で腹面出口角が１０°なる両点を結ぶ直線よ
り小さく、無次元周速が０．９で腹面出口角が３１°な
る点と無次元周速が１．５４で腹面出角が１０°なる両
点を結ぶ直線より大なる領域にあるように設定したこと
を特徴とする軸流タービン回転羽根。 ２、特許請求の範囲第１項において、前記回転羽根の腹
面出口角を、先端部から半径方向内側になるに従つて、
ほぼ直線的に大きくしたことを特徴とする軸流タービン
回転羽根。[Claims] 1. An axial flow turbine having a rotary blade row rotating at a transonic speed, in which the rotary blade row flow path forms a tapered flow path from the front end portion to the rear end portion of the rotary blade. In the radial outer circumferential portion of the blade where the transonic flow occurs, the back and ventral surfaces of the blade surface at the trailing end portion are approximately flat, and the ventral exit angle formed by the ventral surface and the circumferential direction is set as one coordinate axis, On the coordinates where the circumferential velocity of each cross section of the rotary blade is nondimensionalized by the speed of sound, which is taken as the other coordinate axis, the nondimensional circumferential velocity is 0.9 and the ventral exit angle is 41. It is smaller than the straight line connecting the point where the non-dimensional peripheral speed is 1.58 and the ventral exit angle is 10°, and the point where the non-dimensional peripheral speed is 0.9 and the ventral exit angle is 31° and the non-dimensional peripheral speed. 1.54 and a ventral surface angle of 10°. 2. In claim 1, the outlet angle of the ventral surface of the rotary blade is adjusted from the tip toward the inside in the radial direction,
An axial flow turbine rotating blade characterized by being enlarged almost linearly.