JPS6225229A - Inspection pig for pipeline - Google Patents

Abstract

PURPOSE:To detect the position of a leak in a pipeline by incorporating a sensor for inspection, an acceleration sensor, a timer, and a signal processor in a capsule type pig body which is inserted into the pipeline and moved with liquid pressure. CONSTITUTION:Three kinds of signal generating devices, i.e. the sensor 3 for inspection, acceleration sensor 4 for the pig body 2, and time 5, a processors 6 for their signals, a storage device 7, and a power source battery 8 are incorporated in the pig body 2. The pig body 2 is inserted into the pig body 2 and fed by applying liquid pressure, and then when it reaches a leak position, the sensor 3 catches a leak sound and generates an inspection signal. Then, when the pig body 2 reaches the end of the pipeline 1, leak information, acceleration information, and records of time are read out of the storage device 7 to calculate the leak position accurately.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is applicable to pipelines, particularly pipes used for inspecting leakage of pipelines buried underground or laid on the seabed, etc., where inspection from the outside surface is difficult. Regarding line inspection pigs.

<Prior art> For pipelines, especially pipelines buried underground or laid on the seabed that are difficult to inspect from the outside of the pipe, a sensor for inspection is built into a pig or a connection of multiple pigs, and the fluid pressure is measured. There is a conventionally known technique for inspecting the pipeline for deterioration such as perforation leakage from the inner surface of the pipe by running a pig inside the pipeline.

For example, as a method for detecting pipeline leaks, an underwater microphone is attached to the tip of a pig, and an underwater microphone is attached to the tip of the pig to make use of the phenomenon that occurs when fluid inside the pipe leaks from a perforated point in the pipe. A means for processing the signal sound from the microphone to eliminate noise and detect leakage sound, a timer, and a means for simultaneously recording the detected leakage sound and time are incorporated, and the pig is moved inside the pipeline. After pumping with fluid, there is a method of taking out the pig, reading the records, and estimating the location of the leak from the elapsed time based on the start and arrival times of the pig.

<Problems to be Solved by the Invention> However, with the conventional method that combines the inspection means and timer as described above, it is necessary to mark the start time and arrival time of the pig on the recording medium using a specific sound or the like. In addition, if the moving speed of the pig is constant from the beginning to the end of the measurement, the leakage location can be accurately estimated. The moving speed of the pig is not constant because it changes depending on the location, which poses a problem that errors tend to occur in estimating the location of the leak.

The present invention has been made in view of the above-mentioned problems in the prior art, and it overcomes the above-mentioned problems and enables accurate detection of location information of defects such as leaks in particular when inspecting the condition of pipelines such as perforation leaks. The purpose is to provide a possible inspection vig for pipelines.

Means for Solving Problems〉 Therefore, the first invention has a capsule-shaped Vig body that is inserted into a pipeline and is moved by fluid pressure, and a test sensor and an acceleration sensor of the Pig body are installed in the Vig body. A pipeline inspection pig with a configuration that incorporates three types of signal generating devices: a sensor and a timer, a processing device and a storage device for processing and recording these signals, and a battery for power supply necessary for these. In the above structure, the second invention calculates the moving distance of the pig body based on the acceleration signal from the acceleration sensor and the time signal from the timer, instead of outputting the acceleration information to the storage device. This pipeline inspection pig is equipped with an arithmetic circuit that outputs movement distance information to a storage device.

<Function> In the first invention, while the pig body is moving in the pipeline, when the pig body approaches, for example, a leakage point in the pipeline, the inspection sensor catches the leakage sound etc. and issues an inspection signal, The acceleration sensor detects acceleration when the pig body starts, passes through a curved pipe section, etc., and when it stops and generates an acceleration signal.These signals are processed by a processing device and stored in a storage device as leakage information and acceleration information. Sent. A time signal from a timer is also sent to the storage device. Therefore, when the pig body reaches the end of the pipeline, the location of the leakage etc. in the pipeline can be estimated by reading out the leakage information, acceleration information, and time record from the storage device.

In the second invention, by providing a circuit that calculates the moving distance of the pig body, the moving distance of the pig body becomes clear, and it becomes possible to more accurately grasp the location of pipeline leakage, etc.

<Example> Hereinafter, an example of the present invention will be described based on FIGS. 1 to 5.

FIG. 1 shows an embodiment of the first invention, in which a pig body 2 inserted into a pipeline 1 and moved by fluid pressure is configured in a capsule shape.

Inside this VIG body 2, there are three types of signal generating devices: an inspection sensor 3, an acceleration sensor 4 of the PIG body 2, and a timer 5, and a processing device 6 for processing and recording these signals. A storage device 7 and a power supply battery 8 necessary for these are incorporated.

The inspection sensor 3 detects leakage sound from a leakage point in the pipeline 1, and is made of, for example, a submerged microphone, and is provided to protrude outward from the center of the tip of the pig body 2.

The acceleration sensor 4 is of a piezoelectric type or a semiconductor gauge type.

The acceleration sensor 4 is attached so that its direction axis coincides with the traveling direction of the pig body 2, and measures the acceleration of the pig body 2 in the traveling direction.

The processing device 6 includes a test signal processing device that processes the test signal from the test sensor 3 and outputs it as test information, and an acceleration signal processing device that processes the acceleration signal from the acceleration sensor 4 and outputs it as acceleration information. The test signal processing circuit 9 and the acceleration signal processing circuit 10 that constitute these processing devices are constructed as shown in the signal transmission circuit diagram of FIG.

That is, the test signal processing circuit 9 includes a preamplifier 91, a bandpass filter 92, a detection/amplifier 93, and a comparator 94.

The acceleration signal processing circuit 10 includes a preamplifier 101, a detection/
It is composed of an amplifier 102 and a comparator 103.

The operation of each component of these processing devices 9 and 10 will be described later.

The storage device 7 simultaneously stores test information from the test signal processing circuit 9, acceleration information from the acceleration signal processing circuit 10, and time signal from the timer 5.

The following storage device 7 is used.

That is, when reading immediately after pulling out from the pig body 2,
A readable discharge printer or the like is used, and if the stored information is input to a computer for further processing, a RAM (writable semiconductor memory device) or a magnetic storage device is used. Note that the storage device is not particularly limited to such a storage device as long as it can store three to five types of input information over time and substantially simultaneously and can withstand shocks during acceleration and deceleration.

Next, the operation of the pipeline inspection pig having such a configuration will be explained.

When the pig body 2 is inserted into the pipeline 1 as shown in FIG.
While moving through the pipeline 1, when the pipe approaches a leakage point in the pipeline 1, the inspection sensor 3 catches the leakage sound and issues a test signal, and this test signal is input to the test signal processing circuit 9. Ru. Preamplifier 9 of test signal processing circuit 9
1 receives the test signal and amplifies it to an appropriate size for processing in the next stage, and the bandpass filter 92 amplifies the friction sound, flow sound of pumping fluid, and other noises (unnecessary signals) present in the amplified test signal. ) to remove the leakage signal area (mainly 5
0 KHz or higher) is passed through the detector/amplifier 9.
3 converts the leakage signal into a DC signal, and the comparator 94 sends this to the storage device 7 as leakage information only when it receives a DC signal of a certain magnitude or more.

Since the pig body 2 has a large speed change when starting, passing through a curved pipe section, and stopping, the acceleration sensor 4 detects acceleration and generates an acceleration signal, and this acceleration signal is input to the acceleration signal processing circuit 10.

The preamplifier 101 of the acceleration signal processing circuit 10 receives the acceleration signal and amplifies it to an appropriate size for processing in the next stage, the detection/amplifier 102 converts the acceleration signal into a DC signal, and the comparator 103 Only when a DC signal of a magnitude greater than that is received is it sent to the storage device 7 as acceleration information.

The timer 5 periodically sends a time signal to the storage device 7 from the start of the pig body 2 to the stop ratio.

When the pig body 2 arrives at the end of the pipeline 1, the leakage information, acceleration information, and time record are read out from the storage device 7, and the fluid pressure for moving the pig body 2 is kept constant. Since the speed at which the body 2 moves through the straight pipe section of the pipeline 1 is considered to be approximately constant, how far is it from the nearest point among the starting end, terminal end, or a curved pipe section in the middle of the pipeline 1? It is possible to estimate the

Therefore, there is no need to mark the start and arrival times of the pig on the recording medium with a specific sound, as is the case with conventional equipment that simply combines an inspection means and a timer. Errors may occur in estimating the location of leaks if the moving speed is not constant due to the presence of pipe accessories such as curved pipes and valves, or changes in internal friction resistance depending on location due to internal corrosion. This makes it possible to accurately estimate the location of the leak.

FIG. 3 is a signal transmission circuit diagram showing another embodiment of the first invention.

In this embodiment, three acceleration sensors 4 are combined so that their directional axes are perpendicular to each other.
Comprised of X, 4Y, 4Z, the acceleration sensor 4X
, 4Y, and 4Z, the direction axis of one, for example, 4X, is made to coincide with the traveling direction of the pig body 2.

In this case, the acceleration signal processing circuit 10
-4X, 4Y, 421: correspondingly preamplifier 101
X, l0IY.

101Z, detection/amplifier 102χ, 102Y, 10
2Z and comparators 103X, 103Y, 103
It is composed of 2 parts.

Note that, instead of using a combination of three uniaxial sensors, one triaxial sensor may be used as the acceleration sensor 4.

According to such a configuration, the pipeline 1 having a complicated route
Even if the moving speed of the pig body 2 changes, it is possible to estimate the leakage position extremely accurately.

FIG. 4 is a signal transmission circuit diagram showing still another embodiment of the first invention.

In this embodiment, the comparator 94 of the test signal processing circuit 9 is composed of three comparators 94a, 94b, and 94c, and each comparator 94a.

The signal intensity comparison values for 94b and 94C are set in stages.

According to this configuration, it becomes possible to know the exact location of the leakage point and the magnitude of the leakage amount at the same time.

FIG. 5 is a signal transmission circuit diagram showing an embodiment of the second invention.

This embodiment has the structure of the embodiment of the first invention described above,
This pipeline inspection pig has a configuration including an arithmetic circuit 11 that calculates the moving distance of the pig body 2 based on the acceleration signal from the acceleration sensor 4 and the time signal from the timer 5 and outputs the moving distance information to the storage device 7. be.

In this case, the arithmetic circuit 11 receives the acceleration signal from the detection/amplifier 102 of the acceleration signal processing circuit 10 and the time signal from the timer 5, calculates the integral movement distance of the pig body 2, and sends it to the storage device 7. The storage device 7 stores leakage information, acceleration information,
Store moving distance information @ (leak position information) and time.

The type of acceleration sensor 4 in this configuration is preferably a semiconductor gauge type rather than a piezoelectric type from the viewpoint of phase accuracy, DC responsiveness, and the like.

According to this configuration, since the moving distance of the pig body 2 from the starting point to the leakage point becomes clear, the first
The leak position can be determined more accurately than the invention.

In this embodiment, the acceleration information from the acceleration signal processing circuit 10 is sent to the storage device 7, and is stored in the storage device 7 together with leakage information, travel distance information (leakage position information), and time. This has the advantage of increasing the reliability of detecting the location information of the leaked location. Of course, in the second invention, since the moving distance of the pig body 2 is made clear by the moving distance information, acceleration information is not particularly required, and the configuration for storing acceleration information in the storage device 7 may be omitted. .

In this embodiment of the second invention, the configuration of the acceleration sensor 4 and the configuration of the comparator 94 of the test signal processing circuit 9 as shown in FIGS. 3 and 4 may also be adopted.

Further, in both the first and second inventions, the pig may be configured by combining the configuration of the acceleration sensor 4 and the configuration of the comparator 94 of the test signal processing circuit 9 as shown in FIGS. 3 and 4. .

Furthermore, the pig body 2 does not need to be limited to one; the necessary circuits can be distributed and incorporated into multiple pig bodies as appropriate, and the pigs can be electrically and mechanically connected to each other so that each signal can be transmitted. May be used in conjunction with each other.

Further, the inspection sensor 3 is not limited to an ultrasonic microphone for detecting the amount of fluid leakage, but may be an ultrasonic flaw detection probe, a radioactivity sensor, or any other type of probe for pipe inspection. In this case, the test signal processing circuit 9 may have a configuration suitable for the probe.

<Effects of the Invention> As explained above, according to the pipeline inspection pig of the first invention, the pig body inserted into the pipeline and moved by fluid pressure is capsule-shaped, and the inspection pig is inserted into the pipeline and moved by fluid pressure. sensor, pig body acceleration sensor and timer 3
Since the configuration incorporates a seed signal generator, a processing device and storage device for processing and recording these signals, and a battery for power supply necessary for these, the moving speed of the pig is determined at the beginning of the measurement. If the moving speed is not constant from the beginning to the end, and the frictional resistance inside the pipe changes depending on the location due to the presence of piping accessories such as curved pipes and valves, or internal corrosion, etc., errors may occur in estimating the leak location. It is difficult to cause leakage, and the leakage location can be estimated accurately. Further, according to the pipeline inspection pig of the second invention, the calculation circuit calculates the moving distance of the pig body based on the acceleration signal from the acceleration sensor and the time signal from the timer and outputs the moving distance information to the storage device. Because of the structure provided with this, the moving distance of the pig body 2 becomes clear, so the leakage position can be grasped more accurately than in the first invention.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a pig structure according to an embodiment of the first invention;
Figure 2 is a signal transmission circuit diagram of the same embodiment as above, Figures 3 and 4 are signal transmission circuit diagrams of other embodiments, and Figure 5 is a signal transmission circuit diagram of the second embodiment.
FIG. 1 is a signal transmission circuit diagram of an embodiment of the invention. 1...Pipeline 2...Pig body 3...
Inspection sensor 4.4X, 4Y, 4Z... Acceleration sensor 5... Timer 6... Processing device 7.
...Storage device 8...Power supply battery 9...Test signal processing circuit 10...Acceleration signal processing circuit 91.10
1. l0IX, l0IY.

Claims (3)

[Claims] (1) A capsule-shaped pig body inserted into a pipeline and moved by fluid pressure is provided, and inside the pig body, an inspection sensor for inspecting the condition of the pipeline and an acceleration sensor for detecting the acceleration of the pig body are installed. , a timer, a test signal processing device that processes a test signal from the test sensor and outputs it as test information, an acceleration signal processing device that processes an acceleration signal from the acceleration sensor and outputs it as acceleration information, and the test signal processor. A pipeline inspection pig characterized by having a built-in storage device that simultaneously stores inspection information from a device, acceleration information from an acceleration signal processing device, and time signal from a timer, and a battery for power supply. (2) A capsule-shaped pig body inserted into a pipeline and moved by fluid pressure, and inside the pig body, an inspection sensor for inspecting the condition of the pipeline and an acceleration sensor for detecting the acceleration of the pig body. , a timer, a calculation circuit that calculates the moving distance of the pig body based on the acceleration signal from the acceleration sensor and the time signal from the timer, and an inspection signal processing device that processes the inspection signal from the inspection sensor and outputs it as inspection information. and a storage device that simultaneously stores the moving distance information of the pig body from the arithmetic circuit, the inspection information from the inspection signal processing device, and the time signal from the timer, and a battery for power supply. Inspection pig for pipelines. (3) The pipeline inspection pig according to claim 2, wherein the acceleration signal from the acceleration sensor is processed as acceleration information and stored in a storage device.