JPH0451719B2 - - Google Patents
Info
- Publication number
- JPH0451719B2 JPH0451719B2 JP57092610A JP9261082A JPH0451719B2 JP H0451719 B2 JPH0451719 B2 JP H0451719B2 JP 57092610 A JP57092610 A JP 57092610A JP 9261082 A JP9261082 A JP 9261082A JP H0451719 B2 JPH0451719 B2 JP H0451719B2
- Authority
- JP
- Japan
- Prior art keywords
- pressure
- value
- time
- liquid
- measurement
- 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
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17D—PIPE-LINE SYSTEMS; PIPE-LINES
- F17D5/00—Protection or supervision of installations
- F17D5/02—Preventing, monitoring, or locating loss
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Examining Or Testing Airtightness (AREA)
- Pipeline Systems (AREA)
Description
【発明の詳細な説明】
本発明は、援体輸送パイプラインの漏洩検知方
法に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for detecting leakage in a body transport pipeline.
一般に、パイプライン中の液体の圧力は、ポン
プ運転状態の変化や種々の弁操作などのため、常
に変動している。 Generally, the pressure of liquid in a pipeline is constantly fluctuating due to changes in pump operating conditions, various valve operations, and the like.
パイプラインにそつて所定間隔をおいて設けら
れた計測点において、所定のサンプリング時間間
隔△ｔで液体圧力を計測し、時間的に相互に隣り
合う計測信号の計測値同志を差分演算し、前記差
分演算値にもとづいてパイプラインの漏洩検知を
行う方法が提案されている（特開昭56−160499号
公報）。 At measurement points provided at a predetermined interval along the pipeline, the liquid pressure is measured at a predetermined sampling time interval Δt, and a difference is calculated between the measured values of measurement signals that are temporally adjacent to each other. A method has been proposed for detecting leakage in a pipeline based on a calculated difference value (Japanese Patent Application Laid-open No. 160499/1983).
しかし、この方法では、漏洩による圧力降下を
各計測点の圧力変動として把えることにより、漏
洩を検知しようとしている。このため、ポンプ運
転状態の変化や弁操作などによる圧力変動よりも
大きな圧力降下を生む漏洩しか検知できないこと
は明らかである。 However, this method attempts to detect a leak by understanding the pressure drop due to the leak as a pressure fluctuation at each measurement point. Therefore, it is clear that only leaks that cause a pressure drop that is greater than pressure fluctuations caused by changes in pump operating conditions, valve operations, etc. can be detected.
一方、ポンプの運転状態変化や弁操作による圧
力変動は、特性曲線法により高い精度で指定され
ることは最近の種々の研究により明らかとなつて
いる。 On the other hand, various recent studies have revealed that pressure fluctuations due to changes in pump operating conditions or valve operations can be specified with high accuracy using the characteristic curve method.
そこで、本発明の目的は、特性曲線法の考え方
を用いて漏洩以外による圧力変動を推定し、その
推定値と計測値とを比較することによつて比較的
少量の液体の漏洩をも検知できるようにすること
にある。 Therefore, the purpose of the present invention is to estimate pressure fluctuations due to causes other than leakage using the characteristic curve method, and to compare the estimated value with the measured value, thereby making it possible to detect even a relatively small amount of liquid leakage. The purpose is to do so.
本発明の方法は、液体輸送用パイプラインにそ
つて所定間隔をおいて設けられた計測点におい
て、所定のサンプリング時間間隔△ｔで液体圧力
を計測し、ある計測点およびその上・下流側の計
測点の時刻ｔにおける圧力測定値から、その計測
点の時刻ｔ＋△ｔでの漏洩のない場合の圧力を計
算し、この値と時刻ｔ＋△ｔにおける測定値とを
比較することによりパイプラインの液体の漏洩を
検知する。 The method of the present invention measures liquid pressure at a predetermined sampling time interval Δt at measurement points provided at predetermined intervals along a liquid transport pipeline, and From the pressure measurement value at the measurement point at time t, calculate the pressure at that measurement point at time t + △t without leakage, and by comparing this value with the measurement value at time t + △t, the pipeline Detects liquid leaks.
まず、本発明の方法に用いられる基礎式につい
て説明する。 First, the basic formula used in the method of the present invention will be explained.
管内液体の運動方程式および連続の式から次式
が得られる。 The following equation is obtained from the equation of motion of the liquid in the tube and the equation of continuity.
dx／dt＝ａのとき：
du／dt＋ｇ／ａ dH／dt＋ｇ／ａｕ sinθ＋λ／2D｜
ｕ｜ｕ＝
０
dx／dt＝−ａのとき：
du／dt−ｇ／ａ dH／dt−ｇ／ａusinθ＋λ／2D｜ｕ
｜ｕ＝０
ここで、ｘ：パイプラインにそつて測られる距
離
ｔ：時 刻
ｕ：流 速
ａ：音 速
Ｈ：圧力水頭
ｇ：重力加速度
θ：管路傾斜角
λ：管摩擦係数
Ｄ：管内径である。When dx/dt=a: du/dt+g/a dH/dt+g/au sinθ+λ/2D |
u｜u= 0 When dx/dt=-a: du/dt-g/a dH/dt-g/ausinθ+λ/2D｜u
| u=0 Here, x: Distance measured along the pipeline t: Time u: Flow velocity a: Sound velocity H: Pressure head g: Gravitational acceleration θ: Pipe inclination angle λ: Pipe friction coefficient D: This is the inner diameter of the pipe.
上式から、第１図におけるＰ点での圧力水頭、
流速Hp、Upは点Ａ、点Ｂでの値HA、UA、HB、
UBを用いて、次式(1)が求められる。 From the above formula, the pressure head at point P in Figure 1,
The flow velocity Hp, Up is the value H A , U A , H B at point A, point B,
Using U B , the following equation (1) can be obtained.
UP−UA＋ｇ／ａ（HP−HA）＋ｇ／ａUAsinθ
△ｔ＋λ／2D｜UA｜UA△ｔ＝０
UP−UB＋ｇ／ａ（HP−HB）−ｇ／ａUBsinθ
△ｔ＋λ／2D｜UB｜UB△ｔ＝０
∴HP＝（HA＋HB）／２＋（ａ／2g−sinθ△ｔ／２）（U
A−UB）−λ・△ｔ・ａ／4gD（｜UA｜UA−｜UB｜UB）
……
また、HA、UA、HB、UBの値は各計測点での
値HQ、UQ、HR、UR、HS、USを用いて(2)式のよ
うに求められる。 U P −U A +g/a (H P −H A )+g/aU A sinθ
△t＋λ/2D｜U A ｜U A △t=0 U P −U B +g/a(H P −H B )−g/aU B sinθ
△t+λ/2D | U B | U B △t=0 ∴H P = (H A +H B )/2+(a/2g−sinθ△t/2) (U
A −U B ) −λ・△t・a/4gD (｜U A ｜U A −｜U B ｜U B )
... Also, the values of H A , U A , H B , and U B are calculated as shown in equation (2) using the values H Q , U Q , H R , U R , H S , and U S at each measurement point. is required.
ε＝△ｘ／△ｌ＝ａ・△ｔ／△ｌ
HA＝（１−ε）HR＋εHQ、UA＝（１−ε）UR＋εUQ
HB＝（１−ε）HS＋εHQUB＝（１−ε）US＋εUQ……
ここで、△ｘは時間△ｔに進む圧力波の距離、
△ｌは隣り合う計測点間の距離である。 ε=△x/△l=a・△t/△l H A = (1-ε) H R +εH Q , U A = (1-ε) U R +εU Q H B = (1-ε) H S +εH Q U B = (1-ε)U S +εU Q ... Here, △x is the distance of the pressure wave traveling in time △t,
Δl is the distance between adjacent measurement points.
本発明の方法においては、時刻ｔにおいて連続
する３点の圧力HR、HQ、HSを測定し、漏洩のな
い場合の時刻ｔ＋△ｔにおける圧力HPを次の(3)
式によつて推定する。 In the method of the present invention, the pressures H R , H Q , and H S at three consecutive points are measured at time t, and the pressure H P at time t + Δt when there is no leakage is determined by the following equation (3).
Estimate using the formula.
2HP＝HR＋HS＋ａ△ｔ／△ｌ
（2HQ−HR−HS） ……(3)
この推定値を、現実の時刻ｔ＋△ｔにおける圧
力の測定値と比較してパイプラインの液体の漏洩
を検知する。 2H P = H R + H S + a△t/△l (2H Q - H R - H S ) ...(3) Compare this estimated value with the measured value of the pressure at the actual time t + △t to calculate the pipeline Detects liquid leakage.
本発明の方法を実施する工程を第２図および第
３図を参照して説明する。 The steps for carrying out the method of the present invention will be explained with reference to FIGS. 2 and 3.
第１工程：システム起動と同時に演算処理装置
（CPU）のプログラムが起動される。First step: The program of the arithmetic processing unit (CPU) is started at the same time as the system is started.
第２工程：CPU1からテレメータ親局２に圧力測
定指令が発せられ、伝送路（伝送ケーブルあ
るいは無線）３およびテレメータ子局４をか
いして各測定点の圧力伝送器５で測定された
信号がCPU1に入力される。CPU1ではこの
データから各点の圧力を示す圧力テーブルが
作成される。圧力伝送器５はタンク６間を結
ぶ液体搬送路７に所定の間隔△ｌをあけて配
置される。2nd step: A pressure measurement command is issued from the CPU 1 to the telemeter master station 2, and the signal measured by the pressure transmitter 5 at each measurement point is transmitted via the transmission line (transmission cable or wireless) 3 and the telemeter slave station 4. Input to CPU1. CPU1 creates a pressure table showing the pressure at each point from this data. The pressure transmitter 5 is arranged in a liquid conveyance path 7 connecting the tanks 6 at a predetermined interval Δl.
第３工程：圧力テーブルの値から式より△ｔ後
の各点の圧力が計算される。この値が推定圧
テーブルとして記憶される。Third step: The pressure at each point after Δt is calculated from the values in the pressure table using the formula. This value is stored as an estimated pressure table.
第４工程：前回測定から△ｔ経過するのを待つ
て、第２工程と同様の処理が行われる。Fourth step: After waiting for Δt to elapse from the previous measurement, the same process as the second step is performed.
第２工程：推定圧テーブルと圧力テーブルとの比
較により圧力の推定値と実測値との差を計算
し、この値が所定の値を超えていれば、漏洩
ありと判定する。漏洩ありの場合は、第６工
程へ、そうでない場合は第３工程に戻して記
憶する。Second step: Calculate the difference between the estimated pressure value and the actual measured value by comparing the estimated pressure table and the pressure table, and if this value exceeds a predetermined value, it is determined that there is a leak. If there is a leak, go to the 6th step, otherwise go back to the 3rd step and store it.
第６工程：警報表示器８によつて漏洩警報・漏洩
場所等を表示する。Sixth step: The alarm display 8 displays a leak alarm, leak location, etc.
漏洩のない場合の圧力推定には式を用いてい
る。これは式の右辺の第２項および第３項を無
視したものであり、これによる誤差に相当する量
は検知できない。一方、式の右辺の第２項およ
び第３項は液体の圧縮性による密度変化分であ
り、通常の水・石油類の圧縮係数が10-9〜10-8
m2／Kgであることから、圧力変動が10Kg／m2もあ
つたとしても、流速変動は0.01％〜0.1％程度で
あり圧力水頭としては0.1m程度未満となり無視
できるほど小さい。 A formula is used to estimate pressure when there is no leakage. This ignores the second and third terms on the right side of the equation, and the amount equivalent to the error due to this cannot be detected. On the other hand, the second and third terms on the right side of the equation are density changes due to the compressibility of the liquid, and the compression coefficient of normal water and petroleum is 10 -9 to 10 -8
m 2 /Kg, so even if the pressure fluctuation is as much as 10Kg/m 2 , the flow velocity fluctuation will be about 0.01% to 0.1%, and the pressure head will be less than about 0.1m, so small that it can be ignored.
その理由を次に簡単に示す。 The reason for this is briefly explained below.
(1)式において、
UA−UB＝△Ｕ，（UA＋UB）／２＝Ｕと置くと
△Ｕ／Ｕ＝10-4〜10-3
（ａ／2g−sinθ△ｔ／２）△Ｕ−λ△ta／2gDＵ・
△Ｕ＝ａ／2g△Ｕ・（１−gsinθ△ｔ／ａ−λU△ｔ／
Ｄ）
≒ａ／2g△Ｕ＝ａ／2gＵ・△Ｕ／Ｕ：８×10
-3〜0.2m
ここで、ａ：1500m／ｓ程度
ｇ：9.8m／S2
λ：0.01〜0.02
Ｕ：１〜3m／ｓ
Ｄ：0.3〜1m
△ｔ：0.1s程度
sinθ≦１
本発明によれば、ポンプの運転状態の変化や弁
操作等による圧力変動を考慮して△ｔ後の圧力を
推定し、実測値と比較して漏洩を判定するため計
測器誤差に起因する誤差相当量以上の漏洩を正確
に検出することができる。 In equation (1), if we set U A −U B =△U, (U A +U B )/2=U, then △U/U=10 -4 ~10 -3 (a/2g−sinθ△t/2 )△U−λ△ta/2gDU・
△U=a/2g△U・(1−gsinθ△t/a−λU△t/
D) ≒a/2g△U=a/2gU・△U/U: 8×10
-3 to 0.2m Here, a: about 1500m/s g: 9.8m/S 2 λ: 0.01 to 0.02 U: 1 to 3m/s D: 0.3 to 1m △t: about 0.1s sinθ≦1 According to the present invention According to the above, the pressure after △t is estimated by taking into account pressure fluctuations due to changes in pump operating conditions and valve operations, etc., and compared with the actual measured value to determine leakage, which is equivalent to the error due to measuring instrument error or more. leakage can be detected accurately.
第１図は特性曲線法による圧力推定の考え方を
説明する図。第２図は本発明の方法を実施するパ
イプライン設備の概略構成説明図。第３図は本発
明の方法を示すフロー・チヤート。
３……伝送路、４……テレメータ子局、５……
圧力伝送器、６……タンク、７……液体搬送路。
FIG. 1 is a diagram explaining the concept of pressure estimation using the characteristic curve method. FIG. 2 is a schematic structural explanatory diagram of pipeline equipment for implementing the method of the present invention. FIG. 3 is a flow chart illustrating the method of the present invention. 3...Transmission line, 4...Telemeter slave station, 5...
Pressure transmitter, 6...tank, 7...liquid conveyance path.
Claims (1)
隔をあけて複数の計測点を設けること、所定のサ
ンプリング時間間隔△ｔで液体の圧力を計測する
こと、任意の計測点を選定し該計測点とその上流
側および下流側の各計測点における時刻ｔの圧力
測定値から各計測点における時刻ｔ＋△ｔでの漏
洩のない場合の圧力を計算すること、該計算値と
時刻ｔ＋△ｔにおける測定値とを比較することか
らなる液体輸送パイプラインの漏洩検知方法。1. In a pipeline for liquid transportation, provide multiple measurement points at predetermined intervals, measure the pressure of the liquid at a predetermined sampling time interval Δt, select an arbitrary measurement point, and Calculating the pressure in the case of no leakage at time t+△t at each measurement point from the pressure measurement value at time t at each measurement point on the upstream side and downstream side, and combining the calculated value and the measured value at time t+△t. A method for detecting leaks in liquid transport pipelines, which consists of comparing the
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9261082A JPS58211100A (en) | 1982-05-31 | 1982-05-31 | Leakage detecting method of liquid transport pipe line |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9261082A JPS58211100A (en) | 1982-05-31 | 1982-05-31 | Leakage detecting method of liquid transport pipe line |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58211100A JPS58211100A (en) | 1983-12-08 |
| JPH0451719B2 true JPH0451719B2 (en) | 1992-08-19 |
Family
ID=14059200
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9261082A Granted JPS58211100A (en) | 1982-05-31 | 1982-05-31 | Leakage detecting method of liquid transport pipe line |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58211100A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4712182A (en) * | 1983-03-09 | 1987-12-08 | Hitachi, Ltd. | Method of estimating fracture point of pipe line network |
| GB8716032D0 (en) * | 1987-07-08 | 1987-08-12 | British Telecomm | Duct testing |
| GB2475323B (en) * | 2009-11-16 | 2011-10-12 | Alan Jackson | Oil tank and pipeline alarm system and system comprising the same |
| CN111536432A (en) * | 2020-05-28 | 2020-08-14 | 浙江和达科技股份有限公司 | Water supply pipe network monitoring method and system |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5854606B2 (en) * | 1979-07-24 | 1983-12-06 | 三菱電機株式会社 | Solid-liquid separator |
-
1982
- 1982-05-31 JP JP9261082A patent/JPS58211100A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS58211100A (en) | 1983-12-08 |
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