CN105864642A - Novel pipeline leakage detecting device and method - Google Patents

Abstract

The invention discloses a novel pipeline leakage detection device and detection method. There are also three pressure equalizing tubes installed along the pipeline, each pressure equalizing tube is equipped with a pressure sensor, and along the liquid flow direction are the first, second and third pressure sensors respectively, and the data collected by the three pressure sensors is used to analyze the internal sound velocity and The leakage position is detected; the first and third pressure sensors are equipped with the first and second flowmeters along the pipeline where the liquid flows to the inlet; the data collected by the two flowmeters is used to preliminarily judge whether there is a leakage, and then the three pressure sensors are used to collect data in real time The data is used to judge whether there is a final leak, and the pressure wave velocity in the pipeline and the position of the pipeline leak are obtained by calculation. The invention can calibrate the local sound velocity, detect pipeline leakage, detect the situation of small leakage, measure the local sound velocity under different working conditions, reduce the false alarm rate caused by adjusting pumps and valves, and improve the probability of pipeline leakage Positioning accuracy is of great significance for saving energy and protecting the environment.

Description

A new pipeline leak detection device and detection method

technical field

The invention relates to a detection device and a detection method, in particular to a novel pipeline leakage detection device and detection method, which can calibrate the local sound velocity in the pipeline, reduce leakage false alarms, and improve leakage positioning accuracy.

Background technique

Pipeline transportation, railway transportation, road transportation, waterway transportation and air transportation are listed as the five major transportation modes, and have unique advantages in transporting liquids, gases, and slurries. With the rapid development of my country's national economy, pipeline transportation and large heavy equipment play an increasingly important role in economic development. However, with the increase of pipelines and the increase of equipment operation time, pipeline leakage accidents occur frequently due to construction defects, erosion corrosion and man-made damage of pipeline walls.

In the early hours of December 30, 2009, a large amount of diesel oil leaked into the Chishui River in the Weinan branch of PetroChina's Lanzhou-Zhengjiang-Changjiang refined oil pipeline, forming a pollution zone in the Weihe River and entering the Yellow River, causing pollution of the Yellow River. On the night of May 17, 2016, the underground oil pipeline of Piemonte Industries, a mineral oil processing company headquartered in Busala, Liguria, ruptured, causing 550 tons of crude oil to leak, 50 tons of which flowed into the nearby sea.

At present, most of the devices for detecting pipeline leakage are difficult to detect the occurrence of micro-leakage events, and generally adopt the existing constant value for the sound velocity, but in reality the sound velocity will vary with the temperature, the percentage of gas in the pipeline, etc. factors change.

Contents of the invention

In order to detect the occurrence of micro-leakage events, save resources, protect the environment, and improve the accuracy of leak location. The invention proposes a new type of pipeline leakage detection device and detection method, thereby meeting the requirements for detecting micro-leakages. On the premise of meeting the requirements for detecting micro-leakages, the local sound velocity is calibrated, and false alarms caused by adjusting pumps and valves are reduced. The rate improves the location accuracy of pipeline leaks.

The technical scheme adopted in the present invention is:

1. A new pipeline leak detection device:

It includes a centrifugal pump, a pipeline connected to the outlet of the centrifugal pump, and a first electric regulating valve installed on the pipeline at the outlet of the centrifugal pump. There are also three pressure equalizing pipes installed along the pipeline, and one is installed on each pressure equalizing pipe for detecting The hydraulic pressure sensor in the pipeline, the three pressure sensors are the first pressure sensor, the second pressure sensor and the third pressure sensor along the liquid flow direction, and the pressure data collected by the first pressure sensor, the second pressure sensor and the third pressure sensor Detect the leakage position of the pipeline; the first pressure sensor is provided with a first flowmeter along the pipeline where the liquid flows to the inlet, and the third pressure sensor is provided with a second flowmeter along the pipeline where the liquid flows to the outlet, through the first flowmeter and the second flowmeter The flow data collected by the second flowmeter corrects the leak detection results to reduce the false alarm rate caused by adjusting pumps and valves.

The present invention adopts a pressure equalizing tube to install a pressure sensor, and the equalizing tube can play the role of gentle pressure, thereby improving the sensitivity for micro-leakage detection.

The pressure equalizing tube is provided with an exhaust port, which communicates with the pipeline, and the exhaust port is used to discharge the air in the pressure equalizing tube and the pipeline, so as to facilitate the discharge of the air in the pressure equalizing tube before the experimental test.

The pressure equalizing tube is provided with a sensor installation port, and the first pressure sensor, the second pressure sensor and the third pressure sensor are fixed with the sensor installation port by threaded connection.

Both the first pressure sensor and the first flowmeter are installed at the input end of the pipeline, the third pressure sensor and the second flowmeter are installed at the output end of the pipeline, and the second pressure sensor is installed at the first pressure sensor and the third pressure sensor.

Two, a novel pipeline leak detection method, using the detection device, specifically comprises the following steps:

1) Preliminarily judge whether the pipeline leaks through the flow data collected by the first flowmeter and the second flowmeter;

2) After preliminarily judging that the pipeline leaks, the pressure data of various places on the pipeline are collected in real time through the first pressure sensor, the second pressure sensor and the third pressure sensor, and then it is judged whether the pipeline finally leaks;

3) After the leakage is determined, the pressure wave velocity in the pipeline and the position of the pipeline leakage are obtained by calculating the pressure data collected in real time by the pressure sensor.

When the opening of the valve decreases or the pump stops, the pressure collected by the first pressure sensor and the third pressure sensor will both decrease, and when leakage occurs, the pressure collected by the first pressure sensor and the third pressure sensor will also decrease. At this time, it is impossible to judge whether there is a leak in the pipeline through the change of the collected pressure value. Therefore, in the foregoing steps, the leak detection result is corrected by the flow data collected by the first flow meter and the second flow meter.

When the valve opening of the first electric regulating valve decreases, the pump stops or leaks, the changes of the flow values collected by the first flowmeter and the second flowmeter are different. When the opening of the first electric control valve decreases or the pump stops, the flow collected by the first flowmeter and the second flowmeter both decrease, and when leakage occurs, the flow collected by the first flowmeter increases , while the flow rate collected by the second flowmeter decreases, so that it can be judged whether there is leakage in the pipeline. Therefore, on the one hand, the first flowmeter and the second flowmeter can play the role of detecting leakage, and on the other hand, can reduce the false alarm rate caused by adjusting the pump and adjusting the valve.

The step 1) is specifically: if the flow data collected by the first flow meter increases and the flow data collected by the second flow meter decreases, it is preliminarily determined that the pipeline has leaked, otherwise no leak has occurred.

The step 2) is specifically based on the preliminary judgment that the pipeline leaks in the step 1), if the pressure data collected by the first pressure sensor and the third pressure sensor both decrease, it is determined that the pipeline has finally leaked, otherwise No leaks occurred.

Through the first pressure sensor, the second pressure sensor and the third pressure sensor, the pressure data on various places on the pipeline are collected in real time, and according to the distance x between the second pressure sensor and the third pressure sensor, the following formula is used to calculate and obtain the pressure data in the pipeline The pressure wave velocity v (equivalent to the local sound velocity, refers to the speed at which sound propagates in the liquid) to improve positioning accuracy:

$\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; x</span>}}{\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}$

Among them, t1 and t2 represent the time when the pressure wave generated at the pipeline leakage reaches the second pressure sensor and the third pressure sensor respectively, and v is the pressure wave velocity in the pipeline;

Then use the following formula to calculate the location of the pipeline leak:

x1=v×(t2-t3)

Wherein, x1 is the distance from the leak hole to the first sensor, that is, the position of the pipeline leak, and t3 is the time when the pressure wave generated at the pipeline leak reaches the first pressure sensor.

The beneficial effects that the present invention has are:

The invention improves the sensitivity of micro-leakage detection, reduces the false alarm rate caused by adjusting pumps and valves, avoids the waste of resources, and also proposes to calibrate the local sound velocity, thereby improving the positioning accuracy of pipeline leakage detection. There is an exhaust port on the uniform pipe to improve the accuracy of measuring the pressure value in the pipe.

The invention has the advantages of simple structure, low cost and convenient installation and use.

The invention can meet the needs of petroleum, chemical industry and other fields.

Description of drawings

Fig. 1 is a schematic diagram of the experimental device of the present invention.

Fig. 2 is a three-dimensional structure diagram of the pressure equalizing tube of the present invention.

In the figure: 1. Centrifugal pump, 2. First electric regulating valve, 3. First flow meter, 4. First pressure sensor, 5. Leak hole, 6. Second pressure sensor, 7. Third pressure sensor, 8 .Second flow meter, 9. Pipeline, 10. Electric needle valve, 11. Second electric regulating valve, 12. Pressure equalizing pipe, 12.1 Exhaust port, 12.2 Sensor installation port.

detailed description

The present invention will be further described below in conjunction with drawings and embodiments.

Concrete simulation embodiment of the present invention and its implementation work process are:

In the specific implementation, a leakage hole 5 is set on the pipeline 9, and an electric needle valve 10 and a second electric regulating valve 11 are installed at the leakage hole 5. The electric needle valve 10 is used to control the leakage amount, and the second electric regulating valve 2 is used. To control the instant opening and closing of the leakage hole, the second electric regulating valve 11 and the electric needle valve 10 are fixed by threaded connection.

A first pressure sensor 4 is installed 1m before the leak hole 5, a second pressure sensor 6 is installed 1m behind the leak hole 5, and a third pressure sensor 7 is installed 100m behind the leak hole. By observing the numerical changes of the first flowmeter, the first pressure sensor, the third pressure sensor and the second flowmeter, it can be judged whether there is leakage in the pipeline, thereby reducing the false alarm rate caused by pump and valve adjustment. By measuring the time t1 and t2 when the signals from the leakage hole reach the second pressure sensor and the third pressure sensor respectively, and the distance x between the second pressure sensor and the third pressure sensor, the local sound velocity can be calibrated, thereby improving the positioning accuracy. It can be seen from Table 1 that after adopting the new pipeline leakage detection device, its positioning accuracy has been improved to a certain extent, especially for small leaks, its positioning accuracy has been significantly improved. The pressure fluctuation in the pipeline is smoothed by the pressure equalizing tube, thereby improving the sensitivity for micro-leakage detection.

Table 1: Comparison of positioning results after adopting the new leak detection device

It can be seen that the present invention aims to calibrate the local sound velocity, reduce the false alarm rate caused by pump and valve adjustments, and improve the sensitivity for micro-leakage detection. The invention has very great significance for saving energy and protecting the environment.

Claims (8)

1. a novel pipeline leak detecting device, including centrifugal pump (1), is connected to centrifugal pump (1) and goes out Mouthful pipeline (9) and the first electric control valve (2) of being arranged on centrifugal pump (1) exit pipeline (9), It is characterized in that: be also equipped with three balance pipes (12), each pressure pipe (12) along pipeline (9) upper all Being provided with a pressure transducer for hydraulic pressure in detecting pipeline (9), three pressure transducers are along liquid stream To the respectively first pressure transducer (4), the second pressure transducer (6) and the 3rd pressure transducer (7), Gathered by the first pressure transducer (4), the second pressure transducer (6) and the 3rd pressure transducer (7) Pressure data to pipeline (9) reveal position detect；First pressure transducer (4) flows to along liquid The pipeline (9) of entrance is provided with first-class gauge (3), and the 3rd pressure transducer (6) flows to out along liquid The pipeline (9) of mouth is provided with second gauge (8), by first-class gauge (3) and second gauge (8) Leak Detection result is modified by the data on flows gathered.

A kind of novel pipeline leak detecting device the most according to claim 1, it is characterised in that: described Balance pipe (12) on have air vent (12.1), air vent (12.1) communicates with pipeline (9), row QI KOU (12.1) is for discharging the air in balance pipe (12) and pipeline (9).

A kind of novel pipeline leak detecting device the most according to claim 1, it is characterised in that: described Balance pipe (12) on have a sensor installation port (12.2), the first pressure transducer (4), the second pressure Force transducer (6) and the 3rd pressure transducer (7) use with sensor installation port (12.2) threaded solid Fixed.

A kind of novel pipeline leak detecting device the most according to claim 1, it is characterised in that: described The first pressure transducer (4) and first-class gauge (3) be installed in pipeline (9) input end, institute The 3rd pressure transducer (7) stated and second gauge (8) are arranged on pipeline (9) outfan end.

5. a novel pipeline leakage detection method, it is characterised in that described in employing Claims 1 to 4 is arbitrary Detection device, specifically includes following steps:

1) data on flows gathered by first-class gauge (3) and second gauge (8) tentatively judges pipe Whether road (9) there occurs leakage；

2) after tentatively judging that pipeline is revealed, by the first pressure transducer (4), the second pressure sensing On device (6) and the 3rd pressure transducer (7) Real-time Collection pipeline, pressure data everywhere judges pipeline (9) again Finally whether reveal；

3) calculated by the pressure data of pressure transducer (7) Real-time Collection after determining leakage and obtain pipeline (9) Position at interior pressure velocity of wave and pipe leakage.

A kind of novel pipeline leakage detection method the most according to claim 5, it is characterised in that: described Step 1) specifically: if the data on flows that described first-class gauge (3) collects raises and described second The data on flows that gauge (8) collects reduces, then it is assumed that tentatively judge that pipeline (9) there occurs leakage, no The most do not reveal.

A kind of novel pipeline leakage detection method the most according to claim 5, it is characterised in that: described Step 2) specifically in step 1) tentatively judge that pipeline is revealed on the basis of, if described first pressure sensing The pressure data that device (4) and described 3rd pressure transducer (7) collect all reduces, then judge that pipeline is There occurs leakage eventually, the most do not reveal.

A kind of novel pipeline leakage detection method the most according to claim 5, it is characterised in that: pass through Described first pressure transducer (4), the second pressure transducer (6) and the 3rd pressure transducer (7) are real-time Gather pressure data everywhere on pipeline, according to the second pressure transducer (6) and the 3rd pressure transducer (7) Between distance x, use below equation to calculate the pressure velocity of wave v obtained in pipeline, to improve positioning precision:

$v=\frac{x}{t2-t1}$

Wherein, t1 and t2 represents that the pressure wave produced at pipe leakage arrives the second pressure transducer (6) respectively With the time of the 3rd pressure transducer (7), v is the pressure velocity of wave in pipeline；

Then the position at employing below equation calculating acquisition pipe leakage:

X1=v × (t2-t3)

Wherein, x1 is the leak distance to first sensor (4), and t3 is the pressure produced at pipe leakage Reeb arrives the time of the first pressure transducer (4).