JPH0152588B2 - - Google Patents
Info
- Publication number
- JPH0152588B2 JPH0152588B2 JP57043238A JP4323882A JPH0152588B2 JP H0152588 B2 JPH0152588 B2 JP H0152588B2 JP 57043238 A JP57043238 A JP 57043238A JP 4323882 A JP4323882 A JP 4323882A JP H0152588 B2 JPH0152588 B2 JP H0152588B2
- Authority
- JP
- Japan
- Prior art keywords
- runner
- secondary flow
- blade
- inlet
- prevention member
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
- F03B—MACHINES OR ENGINES FOR LIQUIDS
- F03B3/00—Machines or engines of reaction type; Parts or details peculiar thereto
- F03B3/12—Blades; Blade-carrying rotors
- F03B3/125—Rotors for radial flow at high-pressure side and axial flow at low-pressure side, e.g. for Francis-type turbines
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/20—Hydro energy
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Hydraulic Turbines (AREA)
Description
【発明の詳細な説明】
本発明は、フランシス水車ランナに関するもの
である。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a Francis turbine runner.
フランシス水車は、ダム水位が所定の値に達す
る迄の運転のように、設計点から大きく離れた状
態で運転する場合には、激しいキヤビテーシヨン
が発生する。 When a Francis turbine is operated far from the design point, such as when the dam water level reaches a predetermined value, severe cavitation occurs.
このキヤビテーシヨンの発生を防止するために
は、種々のランナが提案されている。第１図およ
び第１図の―断面を示す第２図はその一例を
示すもので、ランナ羽根１の入口部に各羽根を連
ねて環状の整流板４を設けた構造になつている。
２，３は、それぞれ、ランナクラウン、ランナバ
ンド、Diはランナ入口直径を示している（以下、
同一部分には同一符号を付す。）。しかし、この整
流板４は羽根外周部に環状に設けられているた
め、ランナの回転による遠心力が大となり強度上
好ましいものではなく、水力的にも、環状の整流
板４がランナ内を流れる主流の方向をも強制する
ことになり、反つて流れを乱すので、振動、キヤ
ビテーシヨンを減ずるためにはむしろ逆効果とな
ることが実験等でも容易に確認できる。 Various runners have been proposed to prevent cavitation from occurring. FIG. 1 and FIG. 2, which shows a cross-section taken from FIG.
2 and 3 indicate the runner crown and runner band, respectively, and D i indicates the runner inlet diameter (hereinafter,
Identical parts are given the same reference numerals. ). However, since the current plate 4 is provided in an annular shape on the outer periphery of the blade, the centrifugal force due to the rotation of the runner becomes large, which is not preferable in terms of strength. This also forces the direction of the main flow, which in turn disturbs the flow, which can be easily confirmed through experiments and the like to have the opposite effect on reducing vibration and cavitation.
また、別の例には、第３図に示すように、ラン
ナ羽根１の出口に整流板５を設けてランナ内の流
れを制御するものがある。しかし、このような整
流板５を最も流速が大となるランナ出口に設ける
場合には、それ自体がキヤビテーシヨンを誘起す
ることになる。さらに、低落差運動時のキヤビテ
ーシヨンはランナ羽根入口角と流入角とのくいち
がいに起因するものであるから、出口側に整流板
を取り付けてもキヤビテーシヨン防止用としては
効果はない。 In another example, as shown in FIG. 3, a current plate 5 is provided at the outlet of the runner blade 1 to control the flow within the runner. However, if such a baffle plate 5 is provided at the runner outlet where the flow velocity is highest, it will itself induce cavitation. Furthermore, since cavitation during low-head motion is caused by a discrepancy between the runner blade inlet angle and the inflow angle, installing a rectifying plate on the outlet side is not effective in preventing cavitation.
本発明は、このような問題点を除去し、設計落
差より低い落差で運転する場合にランナ羽根入口
に発生する流れの剥離、乱れに起因するキヤビテ
ーシヨンの防止可能なフランシス水車ランナを提
供することを目的とし、フランシス水車ランナの
ランナ羽根の入口部圧力面上に、主流方向に沿つ
て位置し、ランナクラウンからランナバンドに流
れる二次流れを防止する二次流れ防止部材が設け
てあり、該二次流れ防止部材が、前記ランナ羽根
に直角に取り付けられた長方形又は台形の板体よ
りなり、該板体が、ランナ出口直径がDp（ｍ）の
場合、
0.05Dp≦長さ≦0.3Dp
0.01Dp≦高さ≦0.05Dp
0.005Dp≦板厚≦0.03Dp
を満足する寸法を有し、ランナ羽根１枚当り１〜
５枚設けられていることを特徴とするものであ
る。 The present invention aims to eliminate such problems and provide a Francis turbine runner that can prevent cavitation caused by flow separation and turbulence that occurs at the runner blade inlet when operating at a head lower than the design head. A secondary flow prevention member is provided on the inlet pressure surface of the runner blade of a Francis turbine runner along the mainstream direction to prevent secondary flow from flowing from the runner crown to the runner band. If the secondary flow prevention member is a rectangular or trapezoidal plate attached at right angles to the runner blade, and the plate has a runner outlet diameter D p (m), then 0.05D p ≦ length ≦ 0.3D. p 0.01D p ≦Height≦0.05D p 0.005D p ≦Plate thickness≦0.03D p , with dimensions that satisfy p, 1 to 1 per runner blade
It is characterized by being provided with five sheets.
本発明は、従来のフランシス水車ランナにおけ
るキヤビテーシヨンの発生原因の研明結果に基づ
いてなされたものである。 The present invention was made based on the results of research into the causes of cavitation in conventional Francis turbine runners.
一般に、水車は同期速度で規制された一定の回
転速度Ｎ（rpm）で運転される。その時のランナ
羽根入口の周速ui（ｍ／ｓ）は一定値、即ち
ui＝（πN／60）・Di（ｍ／ｓ） ……(1)
である。 Generally, a water turbine is operated at a constant rotational speed N (rpm) regulated at a synchronous speed. At that time, the peripheral speed u i (m/s) at the runner blade inlet is a constant value, that is, u i =(πN/60)·D i (m/s) (1).
落差が設計値あるいはそれに近い値であれば、
ランナ内に流れ込む水の絶対入口速度ベクトルｃ→
１とランナ羽根周速ベクトルｕ→iとのベクトル差、
すなわち、相対入口速度ベクトルｗ→iは、第３図
の―断面を示す第４図のランナ羽根入口速度
三角形に示すように、ランナ羽根入口角度βiと一
致するので、ランナ内の水の流れは羽根に沿つて
無理なく進む。 If the head is at or close to the design value,
Absolute inlet velocity vector of water flowing into the runner c→
1 and the runner blade peripheral speed vector u→ i ,
In other words, the relative inlet velocity vector w → i coincides with the runner blade inlet angle β i , as shown in the runner blade inlet velocity triangle in FIG. moves effortlessly along the wings.
ところが、運転落差が設計値より小となると、
同じく第３図の―断面を示す第５図のランナ
羽根入口速度三角形に示すように、絶対入口速度
ベクトルはｃ→1′に変化する。ｃ→1′の値は、設計落
差Ｈ、低落差H′から
と表わされる。従つて、第５図に示すように、相
対入口速度ベクトルｗ→i′は羽根入口角、βiとくい
違い（Δβ）を生じることになる。 However, when the operating head becomes smaller than the design value,
As shown in the runner blade inlet velocity triangle of FIG. 5, which also shows the cross-section shown in FIG. 3, the absolute inlet velocity vector changes from c→ 1 '. The value of c→ 1 ′ is calculated from the design head H and low head H′. It is expressed as Therefore, as shown in FIG. 5, the relative inlet velocity vector w→i' causes a discrepancy (Δβ) with the blade inlet angle β i .
このくい違いが羽根入口圧力面における剥離６
を発生させ、さらにこれが原因となつて羽根入口
圧力面におけるランナクラウンからランナバンド
へ流れる二次流れを発生する。第６図は二次流れ
を説明する斜視図で、７および８はそれぞれ、主
流（方向）および二次流れ（方向）を示してい
る。この図の示すように、ランナクラウン２から
ランナバンド３へ流れる二次流れ８は隣接の羽根
出口側負圧面方向に流れ込み、元々流速の大なる
部分をさらに加速し、あるいは加振することにな
り、この現象によつて、低落差運転にも拘わら
ず、羽根出口側負圧面に激しいキヤビテーシヨン
９が発生することになる。この発明は、このよう
な検討結果に基づいて合理的な二次流れ防止方法
を探究した結果得られたもので、例えば、羽根に
直角に取り付けられる長方形又は台形の板体を羽
根の入口部圧力面上に主流方向に沿つて位置せし
めた二次流れ防止部材を設けることによつて所期
の目的の達成の可能な点に想到したものである。 This discrepancy causes separation on the impeller inlet pressure surface6.
This causes a secondary flow to flow from the runner crown to the runner band at the blade inlet pressure surface. FIG. 6 is a perspective view illustrating the secondary flow, where 7 and 8 indicate the main flow (direction) and the secondary flow (direction), respectively. As shown in this figure, the secondary flow 8 flowing from the runner crown 2 to the runner band 3 flows toward the suction surface on the outlet side of the adjacent blade, further accelerating or exciting the part that originally had a high flow velocity. Due to this phenomenon, severe cavitation 9 occurs on the negative pressure surface on the exit side of the blade despite low head operation. This invention was obtained as a result of searching for a rational method for preventing secondary flow based on the results of such studies. By providing a secondary flow prevention member positioned along the main flow direction on the surface, it was conceived that the intended purpose could be achieved.
以下、実施例について説明する。 Examples will be described below.
第７図は一実施例の斜視図、第８図は要部の説
明図を示し、１０，１０が二次流れ防止部材で、
１０，１０はランナ羽根１の入口部圧力面上に主
流方向に沿つて位置して設けられた台形の板体よ
りなつている。このようにランナ羽根１の入口部
圧力面上に二次流れ防止部材１０，１０が主流方
向に沿つて設けられていると、ランナクラウン２
からランナバンド３方向に二次流れ１１が流れて
も、二次流れ防止部材１０の台形の板体によつて
その進行が阻害され、その後は台形の板体に沿つ
て流れるようになる。従つて、二次流れ１１は二
次流れ防止部材１０によつて主流と同じ方向へ流
れるようになり、隣接の羽根出口側負圧面方向に
流れ込むのが防止されるのでキヤビテーシヨンが
低減され、それと同時に、水車効率を向上させる
ことが可能となる。 FIG. 7 is a perspective view of one embodiment, and FIG. 8 is an explanatory diagram of the main parts, where 10 and 10 are secondary flow prevention members,
Reference numerals 10 and 10 are trapezoidal plates located on the pressure surface of the inlet portion of the runner blade 1 along the mainstream direction. When the secondary flow prevention members 10, 10 are provided on the pressure surface of the inlet portion of the runner blade 1 along the mainstream direction in this way, the runner crown 2
Even if the secondary flow 11 flows in the direction of the runner band 3, its progress is inhibited by the trapezoidal plate of the secondary flow prevention member 10, and thereafter it flows along the trapezoidal plate. Therefore, the secondary flow 11 is caused to flow in the same direction as the main flow by the secondary flow prevention member 10, and is prevented from flowing toward the suction surface on the outlet side of the adjacent blade, thereby reducing cavitation, and at the same time , it becomes possible to improve water turbine efficiency.
この二次流れ防止部材は、流体力学的、強度的
には、その長さ、高さ、板厚が、ランナ出口直径
がDp（ｍ）の場合、それぞれ、
0.05Dp≦長さ（ｌ）≦0.3Dp
0.01Dp≦高さ（ｈ）≦0.05Dp
0.005Dp≦板厚（ｔ）≦0.03Dp
の条件を満足する場合に最も効果的であり、これ
らの値より小さい場合には二次流れの効果的な防
止ができず、これらの値より大きい場合には重量
の増加による水車効率の低下のため望ましくな
い。また取付板数はランナ羽根１枚当り１〜５枚
が最も効果的である。また、二次流れ防止部材の
外面は、全て角を丸めて主流を阻げないようにす
ることが望ましい。 In terms of hydrodynamics and strength, the length, height, and plate thickness of this secondary flow prevention member are such that, when the runner outlet diameter is D p (m), 0.05D p ≦ length (l )≦0.3D p 0.01D p ≦Height (h)≦0.05D p 0.005D p ≦Thickness (t)≦0.03D p It is most effective when the following conditions are satisfied, and when it is smaller than these values. It is not possible to effectively prevent secondary flows, and values larger than these values are undesirable because the turbine efficiency decreases due to increased weight. The most effective number of mounting plates is 1 to 5 per runner blade. Further, it is desirable that all corners of the outer surface of the secondary flow preventing member be rounded so as not to block the main flow.
このように、実施例のフランシス水車ランナは
設計値よりも低い落差で運転した場合に発生する
二次流れを防止することができ、従つて、この二
次流れによつて生ずる激しいキヤビテーシヨンを
も防止することができ、さらに水車効率も向上さ
せることが可能である。 In this way, the Francis turbine runner of the example can prevent the secondary flow that occurs when operating at a head lower than the design value, and therefore also prevents severe cavitation caused by this secondary flow. Furthermore, it is possible to improve the efficiency of the water turbine.
以上の如く、本発明は設計落差より低い落差で
運転する場合にランナ羽根入口に発生する流れの
剥離、乱れに起因するキヤビテーシヨンの防止可
能なフランシス水車ランナの提供を可能とするも
ので、産業上の効果の大なるものである。 As described above, the present invention makes it possible to provide a Francis turbine runner that can prevent cavitation caused by flow separation and turbulence that occurs at the runner blade inlet when operating at a head lower than the design head, and is useful for industrial purposes. The effect is great.
第１図はフランシス水車ランナの従来例の断面
図、第２図は第１図の―断面図、第３図は同
じく他の従来例の断面図、第４図はよび第５図は
それぞれ異なる運転条件におけるランナ羽根入口
速度三角形を示す第３図の―断面図、第６図
は同じく従来例の斜視図、第７図は本発明のフラ
ンシス水車ランナの一実施例の斜視図、第８図は
第７図の要部断面図である。
１……ランナ羽根、２……ランナクラウン、３
……ランナバンド、７……主流（方向）、１０…
…二次流れ防止部材、１１……二次流れ（方向）。
Figure 1 is a cross-sectional view of a conventional example of a Francis turbine runner, Figure 2 is a cross-sectional view of Figure 1, Figure 3 is a cross-sectional view of another conventional example, and Figures 4 and 5 are different from each other. 3 is a sectional view showing the runner blade inlet velocity triangle under operating conditions, FIG. 6 is a perspective view of the conventional example, FIG. 7 is a perspective view of an embodiment of the Francis turbine runner of the present invention, and FIG. 8 is a sectional view of the main part of FIG. 7. 1...Runner blade, 2...Runner crown, 3
...Runner band, 7...Mainstream (direction), 10...
...Secondary flow prevention member, 11...Secondary flow (direction).
Claims (1)
圧力面上に、主流方向に沿つて位置し、ランナク
ラウンからランナバンドに流れる二次流れを防止
する二次流れ防止部材が設けてあり、該二次流れ
防止部材が、前記ランナ羽根に直角に取り付けら
れた長方形又は台形の板体よりなり、該板体が、
ランナ出口直径がDp（ｍ）の場合、 0.05Dp≦長さ≦0.3Dp 0.01Dp≦高さ≦0.05Dp 0.005Dp≦板厚≦0.03Dp を満足する寸法を有し、ランナ羽根１枚当り１〜
５枚設けられていることを特徴とするフランシス
水車ランナ。[Claims] 1. A secondary flow prevention member is provided on the pressure surface of the inlet of the runner blade of the Francis turbine runner along the mainstream direction and prevents secondary flow from flowing from the runner crown to the runner band. The secondary flow prevention member is made of a rectangular or trapezoidal plate attached at right angles to the runner blade, and the plate has:
When the runner outlet diameter is D p (m), it has dimensions that satisfy 0.05D p ≦ length ≦ 0.3D p 0.01D p ≦ height ≦ 0.05D p 0.005D p ≦ plate thickness ≦ 0.03D p , 1~ per runner blade
Francis water wheel runner is characterized by having five runners.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57043238A JPS58160560A (en) | 1982-03-17 | 1982-03-17 | Francis turbine runner |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57043238A JPS58160560A (en) | 1982-03-17 | 1982-03-17 | Francis turbine runner |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58160560A JPS58160560A (en) | 1983-09-24 |
| JPH0152588B2 true JPH0152588B2 (en) | 1989-11-09 |
Family
ID=12658316
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57043238A Granted JPS58160560A (en) | 1982-03-17 | 1982-03-17 | Francis turbine runner |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58160560A (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19518603A1 (en) * | 1995-05-23 | 1996-11-28 | Klein Schanzlin & Becker Ag | Device to avoid cavitation erosion |
| FR2844560B1 (en) * | 2002-09-13 | 2006-01-27 | Alstom Switzerland Ltd | FRANCIS-TYPE WHEEL AND HYDRAULIC MACHINE EQUIPPED WITH SUCH A WHEEL |
| JP4703578B2 (en) * | 2007-01-19 | 2011-06-15 | 東京電力株式会社 | Francis turbine |
| FR2999243A1 (en) * | 2012-12-11 | 2014-06-13 | Alstom Hydro France | FRANCIS TYPE PUMP TURBINE AND ENERGY CONVERSION INSTALLATION COMPRISING SUCH A TURBINE PUMP |
| EP3203061A1 (en) * | 2016-02-05 | 2017-08-09 | GE Renewable Technologies | Blade for shrouded runner and shrouded runner comprising said blade |
| ES2904815T3 (en) * | 2018-08-03 | 2022-04-06 | Ge Renewable Tech | Preformed cap with inter-blade profiles for hydraulic turbines |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS455762Y1 (en) * | 1966-06-27 | 1970-03-20 | ||
| JPS50142940A (en) * | 1974-04-26 | 1975-11-18 |
-
1982
- 1982-03-17 JP JP57043238A patent/JPS58160560A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS58160560A (en) | 1983-09-24 |
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