JPH07892Y2 - Turbine flow measurement device - Google Patents
Turbine flow measurement deviceInfo
- Publication number
- JPH07892Y2 JPH07892Y2 JP9099888U JP9099888U JPH07892Y2 JP H07892 Y2 JPH07892 Y2 JP H07892Y2 JP 9099888 U JP9099888 U JP 9099888U JP 9099888 U JP9099888 U JP 9099888U JP H07892 Y2 JPH07892 Y2 JP H07892Y2
- Authority
- JP
- Japan
- Prior art keywords
- flow rate
- flow
- pressure
- water turbine
- turbine
- 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 - Lifetime
Links
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- Measuring Volume Flow (AREA)
Description
【考案の詳細な説明】 〔産業上の利用分野〕 本考案は、主にチユーブラ水車、プロペラ水車、カプラ
ン水車などの流量を計測する流量計測装置に関する。[Detailed Description of the Invention] [Industrial field of application] The present invention mainly relates to a flow rate measuring device for measuring the flow rate of a Chubura turbine, a propeller turbine, a Kaplan turbine, and the like.
従来、水車の流量計測には各種の流量計が使用されてい
るが、代表的なものとして羽根車式、超音波式、ピトー
管式などの流量計がある。Conventionally, various flowmeters have been used to measure the flow rate of a water turbine, but typical flowmeters include impeller type, ultrasonic type, Pitot tube type flowmeters.
羽根車式流量計は流路に羽根車を入れ、流体の動圧を利
用してこれを回転させ、その回転速度から瞬時の流量
を、またその回転数から積算流量を計測するものであ
る。An impeller type flow meter is one in which an impeller is inserted in a flow path, the dynamic pressure of a fluid is used to rotate the impeller, and an instantaneous flow rate is measured from its rotational speed, and an integrated flow rate is measured from its rotational speed.
また、超音波式流量計には超音波が流体中を伝播する
際、流体が静止している場合と運動している場合とでは
見かけ上の伝播速度が異なることを利用した標準方式の
ものや、これとは別に超音波ビームの進行方向が流れに
より曲げられる現象を利用したものなどがある。In addition, the ultrasonic flowmeter uses a standard method that utilizes the fact that the apparent propagation speed of an ultrasonic wave is different between when the fluid is stationary and when it is moving. In addition to this, there is a method utilizing a phenomenon that the traveling direction of an ultrasonic beam is bent by a flow.
また、ピトー管式流量計は管路の一断面にピトー管を配
置して流速分布を測定し、流量を求めるものである。こ
の方式にはピトー管により断面各点の全圧を測定すると
ともに管壁に於ける数点で静圧を求める方法が広く行わ
れているが、両圧力を同一点で測定できる流線形ピトー
管を使用する方法も行われている。これらの方法はベル
ヌーイの定理により全圧と静圧との差から速度の関数で
ある動圧を求め、この動圧から得られた速度に計測個所
の断面積を剰じて流量を求めるものである。Further, the Pitot tube type flow meter is one in which a Pitot tube is arranged in one cross section of a pipe line to measure a flow velocity distribution to obtain a flow rate. In this method, a method of measuring the total pressure at each point of the cross section with a Pitot tube and obtaining the static pressure at several points on the tube wall is widely used, but a streamline Pitot tube that can measure both pressures at the same point The method of using is also done. These methods calculate the dynamic pressure as a function of velocity from the difference between total pressure and static pressure by Bernoulli's theorem, and then calculate the flow rate by adding the velocity obtained from this dynamic pressure to the cross-sectional area of the measurement point. is there.
上記のように、従来の水車の流量計測には各種の流量計
が使用されているが、羽根車式流量計は流速が適当な範
囲では羽根車の回転数と流量とがほぼ比例するが、流速
が遅くなると動圧が小さくなるので、羽根車の軸受や流
水と羽根との摩擦の割合が大きくきいてきて計測値が不
安定になる。また、流量が急激に変化したときは羽根車
の慣性のために計測誤差のでる場合がある。従つて、流
速の遅い水車すなわち低落差のチユーブラ水車、プロペ
ラ水車、カプラン水車などには精度の面で使用すること
ができない。As described above, various flowmeters are used to measure the flow rate of the conventional turbine, but in the impeller type flowmeter, the rotational speed of the impeller and the flow rate are almost proportional in the proper flow velocity range. Since the dynamic pressure decreases when the flow velocity becomes slow, the ratio of friction between the impeller bearing or running water and the blade becomes large and the measured value becomes unstable. Further, when the flow rate changes abruptly, a measurement error may occur due to the inertia of the impeller. Therefore, it cannot be used in terms of accuracy for a turbine having a low flow velocity, that is, a low-head Chevula turbine, a propeller turbine, a Kaplan turbine, or the like.
また、超音波式流量計は流れに乱れがあるときや管壁の
境界層の影響が大きいときには、測定精度が著しく低下
する。このために、測定の際には測定部の内径を1m以
上、等断面直管部の長さは測定部の上流側に15倍以上、
下流側に５倍以上、平均流速は0.5m/sec以上とする精度
保持のための厳しい適用条件が要求される。In addition, the ultrasonic flow meter has a significantly reduced measurement accuracy when there is turbulence in the flow or when the influence of the boundary layer of the tube wall is great. For this reason, during measurement, the inner diameter of the measuring part is 1 m or more, the length of the straight pipe part of equal cross section is 15 times or more on the upstream side of the measuring part,
Strict application conditions are required to maintain the accuracy of 5 times or more on the downstream side and the average flow velocity of 0.5 m / sec or more.
ピトー管式流量計の正面図と側面図を第３図に示す。図
に於いて、管路01の一断面に前面に多数の全圧孔を有す
るピトー管04の一対の支持管03が直交する２直径状に配
置されており、多数のピトー管04によつて全圧を測定す
る。従つて、極めて大形で複雑な構造になり、かつ支持
管03は流水によつてその背後にできるカルマン渦と共振
することがあるので、十分に強度を大きくする必要があ
る。このために、水車の流量計測に使用されている従来
のピトー管式流量計はコストが極めて高く、また測定部
の上流側には管路01内径の20倍以上、下流側には５倍以
上の等断面直管部を設けなければならず、大きなスペー
スを要するなどの不具合を抱えている。FIG. 3 shows a front view and a side view of the Pitot tube flow meter. In the figure, a pair of support pipes 03 of a Pitot tube 04 having a large number of all pressure holes on the front surface are arranged in a cross section of the pipe line 01 in two diameters orthogonal to each other. Measure total pressure. Therefore, the structure becomes extremely large and complicated, and the supporting pipe 03 may resonate with the Karman vortex formed behind it due to the flowing water, so it is necessary to sufficiently increase the strength. For this reason, the conventional Pitot tube flow meter used for measuring the flow rate of the water turbine is extremely expensive, and the upstream side of the measuring section is 20 times or more the inner diameter of the pipe line 01 and the downstream side is 5 times or more. However, there is a problem in that a straight pipe section of equal cross section must be provided and a large space is required.
本考案に係る水車の流量計測装置は上記の課題を解決す
ることを目的にしており、水車のトツプカバーに流れに
対面して設けられた全圧検出孔と、水車の水圧鉄管の内
壁に流れに直交して設けらえた静圧検出孔と、上記両検
出孔により得られる差圧から流れの流量を演算して表示
する流量表示計とを備えてなる構成を特徴としている。The flow rate measuring device for a water turbine according to the present invention is intended to solve the above-mentioned problems, and a total pressure detection hole provided on the top cover of the water turbine facing the flow and a flow on the inner wall of the hydraulic iron pipe of the water turbine. It is characterized in that it is provided with a static pressure detecting hole provided orthogonally to each other and a flow rate indicator for calculating and displaying the flow rate of the flow from the differential pressure obtained by the both detecting holes.
即ち、本考案に係る水車の流量計測装置に於いては水車
のトツプカバーおよび水圧鉄管に水車内の流れの全圧、
静圧をそれぞれ測定する検出孔が設けられており、これ
らの圧力検出孔で得られる圧力差に基づいて水車の流量
が流量表示計により演算されて表示される。That is, in the flow rate measuring device for a hydraulic turbine according to the present invention, the total pressure of the flow in the hydraulic turbine is applied to the top cover and the penstock of the hydraulic turbine.
Detection holes for measuring the static pressure are provided, and the flow rate of the water turbine is calculated and displayed by the flow rate indicator based on the pressure difference obtained by these pressure detection holes.
本考案の実施例を第１図および第２図に基づいて説明す
る。なお、第１図および第２図に於ける同一の部品には
同一の符号を付する。第１図は本考案の一実施例に係る
水車の流量計測装置の断面図、第２図は第１図に於ける
II-II矢視図である。An embodiment of the present invention will be described with reference to FIGS. 1 and 2. The same parts in FIGS. 1 and 2 are designated by the same reference numerals. FIG. 1 is a sectional view of a flow rate measuring device for a water turbine according to an embodiment of the present invention, and FIG. 2 is a sectional view of FIG.
It is a II-II arrow line view.
第１図に於いて、チユーブラ水車に水圧鉄管１から矢印
の方向に流入した圧力水はステーリング５、可動ガイド
ベーン６および可動ランナベーン７を経て図示しない放
水路へ排出される。本実施例に係る水車の流量計測装置
はトツプカバー８の頭部に第２図に示すように全圧測定
用ピトー管４の５個の全圧孔が軸方向の流れに対面して
設けられており、ピトー管４によつて検出された全圧P0
は管９を経て差圧計10に伝達される。また、水圧鉄管１
には内壁に検出孔を持つ単数または複数の静圧測定用ピ
トー管11が設けられており、ピトー管11によつて検出さ
れた静圧Ｐは管12を経て差圧計10に伝達される。In FIG. 1, the pressure water flowing from the penstock 1 into the CHUBRA turbine in the direction of the arrow is discharged to a water discharge passage (not shown) via the staying 5, the movable guide vanes 6 and the movable runner vanes 7. In the flow rate measuring device for a water turbine according to this embodiment, as shown in FIG. 2, five total pressure holes of a total pressure measuring pitot tube 4 are provided in the head of the top cover 8 so as to face the axial flow. And the total pressure P 0 detected by the Pitot tube 4.
Is transmitted to the differential pressure gauge 10 via the pipe 9. Also, penstock 1
A static pressure measuring pitot tube 11 having a detection hole on its inner wall is provided in the tube, and the static pressure P detected by the pitot tube 11 is transmitted to the differential pressure gauge 10 via the tube 12.
流量Ｑは m3/secにより求められる。但し、 C: 補正係数 D: 水圧鉄管の内径（ｍ） g: 重力の加速度（9.8m/sec2） γ：水の比重量（1,000kg/m3） P0：全圧（Kg/m3） P: 静圧（Kg/m2） また、実験結果によりL/Db≧１のときＣ＝１、L/Db＜１
のときＣ≠１であり、その値は過去の実績または模型試
験によつて求められる。但し、Ｌはボス部13の始端から
静圧測定位置迄の距離（ｍ）、Dbはボス部の直径（ｍ）
である。また、全圧孔の位置はd/Dbが大きいと境界層の
影響を受けるのでd/Db≦0.25とする必要がある。但し、
ｄは全圧孔の最大ピツチ円直径（ｍ）である。差圧計10
からの差圧を表わす信号は演算回路を備えた流量表示計
14によつて流量に換算され、アナログまたはデジタル表
示される。The flow rate Q is Calculated by m 3 / sec. Where C: correction factor D: inner diameter of penstock (m) g: acceleration of gravity (9.8m / sec 2 ) γ: specific weight of water (1,000kg / m 3 ) P 0 : total pressure (Kg / m 3) ) P: Static pressure (Kg / m 2 ) Also, according to the experimental results, when L / D b ≧ 1, C = 1, L / D b <1
In this case, C ≠ 1, and the value is obtained by past performance or model test. Where L is the distance from the starting end of the boss 13 to the static pressure measurement position (m), and D b is the diameter of the boss (m).
Is. Further, the position of all pressure holes is affected by the boundary layer when d / D b is large, so it is necessary to set d / D b ≦ 0.25. However,
d is the maximum pitch circle diameter (m) of all pressure holes. Differential pressure gauge 10
The signal indicating the differential pressure from the flowmeter is equipped with an arithmetic circuit.
It is converted into a flow rate by 14 and displayed in analog or digital.
チユーブラ水車は渦巻ケーシングを持たず、ケーシング
が円筒形であるので、発電機も通常ケーシング内に設け
られている。同様に、プロペラ水車、カプラン水車にも
渦巻ケーシングがない。このような構造の水車の場合、
水車の出入口の流れは通常整流された状態の軸方向の流
れである。本実施例に係る水車の流量計測装置はこのよ
うな構造上の特徴を利用して、トツプカバー８の頭部に
単数または複数個の全圧測定用のピトー管４の検出孔を
配設するとともに、水圧鉄管１の管壁に検出孔を有する
単数または複数個の静圧測定用のピトー管11を設けてピ
トー管式流量計を形成させ、これにより得られる圧力差
に基づいて水車の流量が流量表示計14により演算されて
表示される。このように、全圧および静圧の取り出しを
それぞれトツプカバー８の頭部と水圧鉄管８の管壁に設
けたことにより従来のピトー管式流量計が簡略化されて
大きなスペースを要さない。また、ピトー管４、11によ
る圧力損失や流れの乱れがなく、水車の運転中も流量の
安定した計測値が得られるとともに計測精度が高く、ピ
トー管４、11が障害にならず、またピトー管４、11が損
傷を受けない。The Chubra turbine does not have a spiral casing, and since the casing is cylindrical, the generator is also usually provided inside the casing. Similarly, propeller turbines and Kaplan turbines also have no spiral casing. In the case of a water turbine with such a structure,
The flow at the inlet and outlet of the water turbine is usually a straightened axial flow. Utilizing such a structural feature, the flow rate measuring device for a water turbine according to the present embodiment disposes one or more detection holes of the pitot tube 4 for measuring total pressure on the head of the top cover 8. The pitot tube type flow meter is formed by providing a pitot tube 11 for measuring static pressure having a detection hole on the tube wall of the penstock 1 to form a pitot tube flow meter. It is calculated and displayed by the flow rate indicator 14. As described above, by providing the total pressure and the static pressure respectively on the head of the top cover 8 and the pipe wall of the penstock 8, the conventional Pitot tube flow meter is simplified and does not require a large space. In addition, there is no pressure loss or flow turbulence due to the Pitot tubes 4 and 11, and a stable measurement value of the flow rate can be obtained even while the water turbine is operating, and the measurement accuracy is high. The tubes 4, 11 are not damaged.
なお、本流量計測装置で最初は流量の絶対値は得られな
いが、一度他の流量計により補正を行えば以後は正確な
流量計測ができ、また圧力計、電力計と組み合わせてシ
ステム化すれば水車効率が判るので、経年変化による水
車効率の低下の判断が可能になる。The absolute value of the flow rate cannot be obtained at first with this flow rate measuring device, but once it is corrected by another flow meter, accurate flow rate measurement can be performed thereafter, and it can be systemized by combining it with a pressure gauge and a power meter. For example, since the turbine efficiency can be known, it is possible to judge the deterioration of turbine efficiency due to aging.
本考案に係る水車の流量計測装置は前記の通り構成され
ており、このように設けられた圧力の検出孔で得られる
圧力差に基づいて水車の流量が流量表示計により演算さ
れて表示されるので、安定した計測値が得られるととも
に計測精度が高く、構造が極めて簡単でコストが低いう
えに大きなスペースを要さないなどの効果が奏せられ
る。The flow rate measuring device of the water turbine according to the present invention is configured as described above, and the flow rate of the water turbine is calculated and displayed by the flow rate indicator based on the pressure difference obtained by the pressure detection hole thus provided. Therefore, stable measurement values can be obtained, measurement accuracy is high, the structure is extremely simple, the cost is low, and a large space is not required.
第１図は本考案の一実施例に係る水車の流量計測装置の
断面図、第２図は第１図に於けるII-II矢視図、第３図
（ａ）は従来のピトー管式流量計の正面図、第３図
（ｂ）はその側面図である。 １……水圧鉄管、４……全圧測定用のピトー管、８……
トツプカバー、10……差圧計、12……静圧測定用のピト
ー管、14……流量表示計。1 is a sectional view of a flow rate measuring device for a water turbine according to an embodiment of the present invention, FIG. 2 is a view taken along the line II-II in FIG. 1, and FIG. 3 (a) is a conventional Pitot tube type. A front view of the flow meter and FIG. 3 (b) are side views thereof. 1 ... Hydraulic iron tube, 4 ... Pitot tube for total pressure measurement, 8 ...
Top cover, 10 ... Differential pressure gauge, 12 ... Pitot tube for static pressure measurement, 14 ... Flow rate indicator.
Claims (1)
られた全圧検出孔と、水車の水圧鉄管の内壁に流れに直
交して設けられた静圧検出孔と、上記両検出孔により得
られる差圧から流れの流量を演算して表示する流量表示
計とを備えてなることを特徴とする水車の流量計測装
置。1. A total pressure detecting hole provided in a top cover of a water turbine facing the flow, a static pressure detecting hole provided in an inner wall of a hydraulic iron pipe of the water turbine perpendicularly to the flow, and both of the above detection holes. A flow rate measuring device for a water turbine, comprising: a flow rate indicator that calculates and displays a flow rate of a flow from a generated differential pressure.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9099888U JPH07892Y2 (en) | 1988-07-11 | 1988-07-11 | Turbine flow measurement device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9099888U JPH07892Y2 (en) | 1988-07-11 | 1988-07-11 | Turbine flow measurement device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0212624U JPH0212624U (en) | 1990-01-26 |
| JPH07892Y2 true JPH07892Y2 (en) | 1995-01-11 |
Family
ID=31315499
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9099888U Expired - Lifetime JPH07892Y2 (en) | 1988-07-11 | 1988-07-11 | Turbine flow measurement device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07892Y2 (en) |
-
1988
- 1988-07-11 JP JP9099888U patent/JPH07892Y2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0212624U (en) | 1990-01-26 |
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