CN112240818A - Device and method for detecting leakage point of inner pipe of long-distance buried double-wall pipe - Google Patents
Device and method for detecting leakage point of inner pipe of long-distance buried double-wall pipe Download PDFInfo
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- CN112240818A CN112240818A CN202011109772.0A CN202011109772A CN112240818A CN 112240818 A CN112240818 A CN 112240818A CN 202011109772 A CN202011109772 A CN 202011109772A CN 112240818 A CN112240818 A CN 112240818A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M3/00—Investigating fluid-tightness of structures
- G01M3/02—Investigating fluid-tightness of structures by using fluid or vacuum
- G01M3/04—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point
- G01M3/20—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using special tracer materials, e.g. dye, fluorescent material, radioactive material
- G01M3/202—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using special tracer materials, e.g. dye, fluorescent material, radioactive material using mass spectrometer detection systems
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- 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
- F17D5/005—Protection or supervision of installations of gas pipelines, e.g. alarm
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- 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
- F17D5/04—Preventing, monitoring, or locating loss by means of a signalling fluid enclosed in a double wall
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M3/00—Investigating fluid-tightness of structures
- G01M3/02—Investigating fluid-tightness of structures by using fluid or vacuum
- G01M3/04—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point
- G01M3/20—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using special tracer materials, e.g. dye, fluorescent material, radioactive material
- G01M3/22—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using special tracer materials, e.g. dye, fluorescent material, radioactive material for pipes, cables or tubes; for pipe joints or seals; for valves; for welds; for containers, e.g. radiators
- G01M3/222—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using special tracer materials, e.g. dye, fluorescent material, radioactive material for pipes, cables or tubes; for pipe joints or seals; for valves; for welds; for containers, e.g. radiators for tubes
Abstract
The invention belongs to the technical field of pipeline leakage point detection and positioning, and particularly relates to a device and a method for detecting leakage points of an inner pipe of a long-distance buried double-wall pipe, wherein the device comprises the following steps: the method comprises the following steps: the device comprises a flow supply control device A, an interlayer pressurizing and pressure maintaining device B, a data acquisition and analysis device C, a pipeline to be detected, a plurality of transmission cables and a plurality of pressure-bearing hoses; the flow supply control device A is connected with the data acquisition and analysis device C through a transmission cable; one end of the detected pipeline is connected with the flow supply control device A, and the other end of the detected pipeline is connected with the data acquisition and analysis device C; and an interlayer pressurizing and pressure maintaining device B is arranged at the interlayer of the detected pipeline.
Description
Technical Field
The invention belongs to the technical field of pipeline leakage point detection and positioning, and particularly relates to a device and a method for detecting leakage points of an inner pipe of a long-distance buried double-wall pipe.
Background
The hydrogen transportation pipeline of a certain nuclear power station is a double-wall pipeline, and the concentration of hydrogen is continuously increased in an interlayer of an inner pipe and an outer pipe of the pipeline. Since hydrogen is a dangerous combustible gas with low ignition energy, wide explosion limit and high combustion rate, hydrogen leakage of the inner pipe in the double-wall transportation pipeline is generated, and accumulated in the interlayer of the inner pipe and the outer pipe, so that the ignition risk is increased, and the positioning of the leakage point of the inner pipe of the double-wall hydrogen transportation pipeline is particularly urgent.
At present, the mature methods for positioning the leakage point of the long-distance buried hydrogen transportation double-wall pipeline in the power industry are few, the oil and gas transportation industry is mainly provided with a leakage inspection device in the pipeline installation stage in advance and needs to be conducted with weak current regularly to carry out leakage inspection work, in addition, the leakage inspection device is not arranged in the hydrogen transportation double-wall pipeline in the installation stage in advance, and due to the flammable and explosive properties of hydrogen, the energization detection method is not suitable for positioning the leakage point of the hydrogen pipeline, so that a safe and reliable leakage point positioning device needs to be researched and designed to position the leakage point position of the inner pipe of the long-distance buried hydrogen transportation double-wall pipeline, and the technical.
Disclosure of Invention
The invention aims to design a device and a method for detecting leakage points of an inner pipe of a long-distance buried double-wall pipe, which are used for solving the technical problems that the hydrogen leakage points of the inner pipe of the hydrogen transportation double-wall pipe are not easy to position and the danger coefficient of a method for detecting the leakage points is high in the prior art.
The technical scheme of the invention is as follows:
the utility model provides a long distance buries double-walled pipe inner tube leak source detection device, includes: the device comprises a flow supply control device A, an interlayer pressurizing and pressure maintaining device B, a data acquisition and analysis device C, a pipeline to be detected, a plurality of transmission cables and a plurality of pressure-bearing hoses; the flow supply control device A is connected with the data acquisition and analysis device C through a transmission cable; one end of the detected pipeline is connected with the flow supply control device A, and the other end of the detected pipeline is connected with the data acquisition and analysis device C; and an interlayer pressurizing and pressure maintaining device B is arranged at the interlayer of the detected pipeline.
The flow control device a includes: the device comprises a compressed air source A, a pressure stabilizing tank, a pressure gauge, a flow regulating valve, a switch valve A, a switch valve B, a flow sensor, a dew point thermometer, a temperature sensor, a standard leak hole, a connecting flange and a plurality of pressure-bearing hoses;
the compressed air source is connected with one end of the pressure stabilizing tank through a pressure-bearing hose, and the other end of the pressure stabilizing tank is sequentially connected with a pressure gauge, a flow regulating valve, a switch valve A, a flow sensor, a dew point thermometer, a temperature sensor and a connecting flange in series through the pressure-bearing hose;
one end of the switch valve B is arranged on the pressure-bearing hose between the flow regulating valve and the switch valve A, and the other end of the switch valve B is arranged on the pressure-bearing hose between the flow sensor and the dew point thermometer; a standard leak hole is also formed in the pressure-bearing hose between the temperature sensor and the connecting flange;
the connecting flange is connected to one end of the detected pipeline.
The interlayer pressurizing and pressure maintaining device B comprises: the device comprises a helium gas source, a compressed air source B, a flowmeter C, a mixing pressure stabilizing tank, a helium concentration measuring instrument, an absolute pressure meter A, a pressure sensor, an absolute pressure meter B, a switch valve C, a switch valve D, a vacuum pump and a plurality of pressure-bearing hoses; the mixed pressure stabilizing tank is respectively connected with a helium gas source and a compressed air source B through pressure-bearing hoses, the mixed pressure stabilizing tank is also connected with an interlayer of the detected pipeline through the pressure-bearing hoses, and a pressure-insulating meter A, a switch valve C, a pressure sensor, a switch valve D and a pressure-insulating meter B are sequentially arranged on the pressure-bearing hoses between the mixed pressure stabilizing tank and the interlayer of the detected pipeline; the switch valve D is connected with a vacuum pump;
a flow meter B is also arranged on the pressure-bearing hose between the helium gas source and the mixing pressure-stabilizing tank; and a flow meter C is also arranged on the pressure-bearing hose between the compressed air source B and the mixed pressure stabilizing tank.
The data acquisition and analysis device C further includes: the system comprises a data acquisition computer, a helium mass spectrometer leak detector, a mass spectrometer suction gun, a connecting flange and a current/digital converter; the current/digital converter is respectively connected with the data acquisition computer and the helium mass spectrometer leak detector through transmission cables, and the helium mass spectrometer leak detector is also connected with a mass spectrometer suction gun through the transmission cables; the mass spectrometer suction gun is provided with a connecting flange; the connecting flange is connected with the other end of the detected pipeline.
The current/digital converter is also connected with the flow sensor of the flow supply control device a through a transmission cable, and the current/digital converter is also connected with the temperature sensor of the flow supply control device a through a transmission cable.
The pressure-bearing hoses are all hard pressure-bearing hoses, and instrument pressure-leading pipe joints are arranged on the pressure-bearing pipelines.
Pressure-bearing hose joints are arranged on the pressure stabilizing tank and the mixed pressure stabilizing tank.
A detection and positioning method of the device for detecting the leak point of the inner pipe of the long-distance buried double-wall pipe comprises the following steps:
the method comprises the following steps: connecting the flow supply control device A and the data acquisition and analysis device C with the detected pipeline through the connecting flange A and the connecting flange B; connecting the current/digital converter, the data acquisition computer and the helium mass spectrometer leak detector by using a transmission cable, respectively introducing a power supply to the current/digital converter, the data acquisition computer and the helium mass spectrometer leak detector, and placing a mass spectrometer suction gun at the outlet end of an inner pipe of a detected pipeline;
step two, inner tube initial inspection: opening a compressed air source A, closing a switch valve A and a connecting flange, opening a switch valve B and a flow regulating valve, and filling compressed air into the inner pipe of the pipeline to be detected, wherein the pressure intensity of the compressed air is greater than 0.1 MPa; at the moment, the interlayer of the pipeline to be detected keeps atmospheric pressure, and the leakage rate of the inner pipe of the pipeline to be detected is measured after the interlayer is stabilized for four hours; selecting a proper reference leak hole to be arranged at the position of the standard leak hole;
step three, filling helium into the interlayer of the pipeline to be detected: closing the switch valve, opening the switch valve, and starting the vacuum pump to vacuumize the interlayer of the pipeline to be detected; stopping the vacuum pump, opening the switch valve, closing the switch valve, opening the helium bottle and the compressed air bottle, and filling a mixed gas of helium gas and air with a certain concentration into the interlayer; the switch valve is closed after the pressure is increased to a certain value;
step four, detection: opening the switch valve A and closing the switch valve B, and regulating the air flow of the inner pipe to V by the flow transmitter1(ii) a After the air flow rate is stable and the helium mass spectrometer leak detector signal is stable, adjusting the flow regulating valve to regulate the air flow rate to V2(ii) a If leakage points exist, helium concentration curves on the helium mass spectrometer leak detector and the data acquisition computer show obvious mutation, the mutation times represent the number of the leakage points, and the data acquisition computer calculates the leakage points according to the time T between the concentration change moment of the helium mass spectrometer leak detector and the last concentration change moment, the air temperature T, the pipeline sectional area S and the pipeline flow velocity V2The distance between the leak point and the suction gun mouth of the mass spectrometer leak detector is calculated according to the parameters, and the formula for calculating the distance between the leak point and the suction gun mouth of the mass spectrometer leak detector is as follows (1):
where 273 is the fixed parameter value, i.e., kelvin temperature corresponding to 0 ℃.
The invention has the beneficial effects that:
according to years of helium leakage detection experience in the industry, through a plurality of test bench simulation tests, the invention designs a long-distance double-wall pipe inner pipe leakage point positioning device based on a helium leakage detection method, and the leakage point positioning of the inner pipe of the buried double-wall pipe is implemented by taking the flange port positions at the inlet end and the outlet end of the pipeline above the ground as detection interfaces, so that the number and the position of the leakage points of the inner pipe of the buried double-wall pipe are determined.
(1) The device provided by the invention is based on the principle of correlation between leak rate and speed of the leak hole, provides a leak point detection position function of the inner pipe of the long-distance double-wall pipe, can detect and verify whether the pipe leaks or not and determine the number of leak points, and has high leak point identification sensitivity due to the adoption of a helium leak detection method;
(2) the invention provides a long-distance double-wall pipe inner pipe leakage point positioning function, which can accurately position the leakage point position of the double-wall pipe inner pipe;
(3) according to the device, the reference leak hole is arranged at one section of the pipeline, and errors caused by the reaction time of the leak detector and the reaction time of the suction gun are effectively reduced through relative time recording;
(4) the device can detect the number and the accurate position of the leak points of the whole pipe section only by being arranged at two ends of a double-wall pipe to be detected, the middle pipe does not need any operation, and the device can detect and position the leak points of the inner pipe of the long-distance double-wall pipe such as a submarine tunnel, an oil-gas pipeline, an overhead pipeline, an underground pipeline and the like;
(5) the leakage point positioning device works by using helium and compressed air as media, is safe and reliable, and can perform leakage detection in flammable and explosive places, high-temperature places and other high-risk places.
Drawings
FIG. 1 is a schematic structural view of a long-distance buried double-wall pipe inner pipe leak source detection device designed by the present invention;
wherein: 1. the device comprises a compressed air source A, a compressed air source 2, a pressure stabilizing tank, a pressure gauge 3, a flow regulating valve 4, a switching valve 5, a switching valve A, a switching valve 6, a switching valve B, a flow transmitter 7, a leakage point thermometer 8, a temperature sensor 9, a standard leak hole 10, a connecting flange A, a helium gas source 12, a compressed air source B, a compressed air source 14, a flow meter A, a flow meter B, a helium concentration meter 16, a mixed pressure stabilizing tank 17, an absolute pressure meter A, an absolute pressure sensor 19, a pressure sensor 20, an absolute pressure meter B, a pressure isolating meter 21, a switching valve C, a switching valve D, a vacuum pump 23, a connecting flange 24, a helium mass spectrometer leak detector 25, a data acquisition computer 26, a current/digital converter 27, a detected pipeline 28 and a mass spectrometer suction gun 29.
Detailed Description
The invention will be further described with reference to the following figures and examples:
the device of the invention consists of a flow supply control device A, an interlayer pressurizing/pressure maintaining device B and a data acquisition and analysis device C. Under the condition that the interlayer environment of the detected pipeline 28 is not changed, the flow change of the inner pipe of the detected pipeline 28 can cause the indication value of the helium mass spectrometer leak detector to correspondingly change, the device utilizes the principle to detect and calculate the distance between a leak point and a mass spectrometer suction gun and the number of the leak points, and the device has the following specific structure:
the utility model provides a long distance buries double-walled pipe inner tube leak source detection device, includes: the device comprises a flow supply control device A, an interlayer pressurizing and pressure maintaining device B, a data acquisition and analysis device C, a pipeline 28 to be detected, a plurality of transmission cables and a plurality of pressure-bearing hoses; the flow supply control device A is connected with the data acquisition and analysis device C through a transmission cable; one end of the detected pipeline 28 is connected with the flow supply control device A, and the other end of the detected pipeline 28 is connected with the data acquisition and analysis device C; and an interlayer pressurizing and pressure maintaining device B is arranged at the interlayer of the detected pipeline 28.
The detected pipeline 28 is a double-wall hydrogen transportation pipeline;
the flow control device a includes: the device comprises a compressed air source A1, a pressure stabilizing tank 2, a pressure gauge 3, a flow regulating valve 4, a switch valve A5, a switch valve B6, a flow sensor 7, a dew point thermometer 8, a temperature sensor 9, a standard leak hole 10, a connecting flange 11 and a plurality of pressure-bearing hoses;
the compressed air source 1 is connected with one end of the pressure stabilizing tank 2 through a pressure-bearing hose, and the other end of the pressure stabilizing tank 2 is sequentially connected with a pressure gauge 3, a flow regulating valve 4, a switch valve A5, a flow sensor 7, a dew point thermometer 8, a temperature sensor 9 and a connecting flange 11 in series through the pressure-bearing hose;
one end of the switch valve B6 is arranged on a pressure-bearing hose between the flow regulating valve 4 and the switch valve A5, and the other end of the switch valve B6 is arranged on a pressure-bearing hose between the flow sensor 7 and the dew-point thermometer 8; a standard leak hole 10 is also arranged on the pressure-bearing hose between the temperature sensor 9 and the connecting flange 11;
the connecting flange 11 is also connected with one end of a pipeline 28 to be detected.
The flow control device a is used to provide various flows of air. Wherein, the pressure stabilizing tank provides an air source for stabilizing the pressure source;
the switch valve A5 and the flow sensor 7 are used for controlling the input flow of the inner pipe of the detected pipeline; the switch valve B6 is used for switching to a large-flow mode to purge the inner pipe of the detected pipeline 28; the pressure gauge 3, the temperature sensor 9 and the dew point thermometer 8 are used for collecting data and correcting the result.
The interlayer pressurizing and pressure maintaining device B comprises: a helium gas source 12, a compressed air source B13, a flowmeter B14, a flowmeter C15, a mixing pressure stabilizing tank 17, a helium concentration measuring instrument 16, an absolute pressure gauge A18, a pressure sensor 19, an absolute pressure gauge B20, a switch valve C21, a switch valve D22, a vacuum pump 23 and a plurality of pressure-bearing hoses; the mixed pressure stabilizing tank 17 is respectively connected with the helium gas source 12 and the compressed air source B13 through pressure-bearing hoses, the mixed pressure stabilizing tank 17 is also connected with an interlayer of the detected pipeline 28 through the pressure-bearing hoses, and a pressure-insulating meter A18, a switch valve C21, a pressure sensor 19, a switch valve D22 and a pressure-insulating meter B20 are sequentially arranged on the pressure-bearing hoses between the mixed pressure stabilizing tank 17 and the interlayer of the detected pipeline 28; the switch valve D22 is also provided with a vacuum pump 23;
a flow meter B14 is also arranged on the pressure-bearing hose between the helium gas source 12 and the mixing pressure-stabilizing tank 17; a flow meter C15 is also arranged on the pressure-bearing hose between the compressed air source B13 and the mixing pressure-stabilizing tank 17.
The interlayer pressure maintaining/pressurizing device is used for supplying and maintaining helium with proper concentration to the interlayer of the detected pipeline 28. Wherein, the mixing pressure-stabilizing tank 17 provides a fully mixed space for the introduced gas source; the flow meter B14 and the flow meter C15 controlled the flow rate to adjust the helium concentration. The vacuum pump 23 is used to evacuate the space in the pipe 28 to be inspected. After the helium is filled, the helium concentration in the space reaches a required value.
The data acquisition and analysis device C further includes: a data acquisition computer 26, a helium mass spectrometer leak detector 25, a mass spectrometer suction gun 29, a connecting flange 24 and a current/digital converter 27; the current/digital converter 27 is respectively connected with the data acquisition computer 26 and the helium mass spectrometer leak detector 25 through transmission cables, and the helium mass spectrometer leak detector 25 is also connected with the mass spectrometer suction gun 29 through the transmission cables; the mass spectrometer suction gun 29 is provided with the connecting flange 24; the connecting flange 24 is connected to the other end of the pipe 28 to be tested.
The current/digital converter 27 is also connected to the flow sensor 7 of the flow supply control device a via a transmission cable, and the current/digital converter 27 is also connected to the temperature sensor 9 of the flow supply control device a via a transmission cable.
The data acquisition computer 26 is used for counting and displaying data information such as flow rate, temperature, helium concentration, time and the like.
And the data acquisition and processing device C is used for detecting the concentration of helium, and analyzing by acquiring data from the flow control device A and the interlayer pressure maintaining and pressurizing device B to obtain the accurate position of a leakage point.
The helium mass spectrometer leak detector 25 and the mass spectrometer suction gun 29 are used for detecting the concentration change of helium in an inner pipe of a detected pipeline 28, the transmission cable is used for summarizing sensor data of the flow control device A and the interlayer pressure maintaining and pressurizing device B, and the data acquisition computer 26 is used for analyzing all data to finally obtain the accurate position of a leakage point.
The pressure-bearing hoses are all hard pressure-bearing hoses, and instrument pressure-leading pipe joints are arranged on the pressure-bearing pipelines.
Pressure-bearing hose joints are arranged on the pressure stabilizing tank 2 and the mixed pressure stabilizing tank 17.
A detection and positioning method of the device for detecting the leak point of the inner pipe of the long-distance buried double-wall pipe comprises the following steps:
the method comprises the following steps: the flow supply control device A and the data acquisition and analysis device C are connected with the detected pipeline 28 through a connecting flange A11 and a connecting flange B24; connecting a current/digital converter 27, a data acquisition computer 26 and a helium mass spectrometer leak detector 25 by using a transmission cable, respectively introducing power into the current/digital converter 27, the data acquisition computer 26 and the helium mass spectrometer leak detector 25, and placing a mass spectrometer suction gun 29 at the outlet end of an inner pipe of a detected pipeline 28;
step two, inner tube initial inspection: opening a compressed air source A1, closing a switch valve A5 and a connecting flange 24, opening a switch valve B6 and a flow regulating valve 4, and filling compressed air into an inner pipe of a detected pipeline 28, wherein the pressure of the compressed air is more than 0.1 MPa; at the moment, the interlayer of the pipeline 28 to be detected keeps atmospheric pressure, and the leakage rate of the inner pipe of the pipeline 28 to be detected is measured after the pipeline is stabilized for four hours; selecting a proper reference leak hole to be arranged at the position of the standard leak hole 10;
step three, filling helium into the interlayer of the pipeline to be detected: closing the switch valve 21, opening the switch valve 22, and starting the vacuum pump 23 to vacuumize the interlayer of the pipeline to be detected; stopping the vacuum pump 23, opening the switch valve 21, closing the switch valve 22, opening the helium bottle 12 and the compressed air bottle 13, and filling a mixed gas of helium gas and air with a certain concentration into the interlayer; the switch valve 21 is closed after the pressure is increased to a certain value;
step four, detection: the switching valve A5 is opened and the switching valve B6 is closed, and the air flow of the inner pipe is adjusted to V by the flow transmitter 71(ii) a After the air flow rate is stable and the helium mass spectrometer leak detector signal is stable, adjusting the flow regulating valve to regulate the air flow rate to V2(ii) a If leakage points exist, helium concentration curves on the helium mass spectrometer leak detector 25 and the data acquisition computer 26 show obvious mutation, the mutation times represent the number of the leakage points, and the data acquisition computer 26 calculates the time T between the concentration change moment of the helium mass spectrometer leak detector and the last concentration change moment, the air temperature T, the pipeline section area S and the pipeline flow velocity V according to the time T between the concentration change moment and the last concentration change moment, the air temperature T, the pipeline section area S and the pipeline flow velocity V2The distance between the leak point and the suction gun mouth of the mass spectrometer leak detector is calculated by the parameters, and the formula for calculating the distance between the leak point and the suction gun mouth of the mass spectrometer leak detector is as follows(1)：
Where 273 is the fixed parameter value, i.e., kelvin temperature corresponding to 0 ℃.
Test verification
The device of the invention develops a 600m double-wall pipe simulation leak point positioning test for nearly thousands of times in 6 months in a laboratory, and the test result shows that the position of the leak point can be completely detected by using the device, and the error can be controlled within 1 percent.
The device is applied to the check of the inner pipe leakage point of the hydrogen double-wall pipe of a certain nuclear power station for the first time, the matched detection steps are combined, the inner pipe leakage point of the double-wall pipe with the length of 1050 meters from a hydrogen station to a conventional island of a No. 4 unit is positioned, the inner pipe leakage point is successfully positioned, and after the ground is excavated, verification shows that the deviation between the positioning position and the actual leakage point position is only 4 cm. Greatly reducing the defect eliminating time and the workload of replacing the defective pipeline.
Evaluation of effects
The device can safely, accurately and flexibly detect the position of the leakage point of the inner tube of the double-wall tube, uses helium and air as detection media, has a relatively simple structure, and has the characteristics of high safety, good accuracy and relatively simple and convenient implementation. When the device is used, the detected object does not need to be heated, electrified and the like, and can be completely used in the environment of flammable and explosive places.
The present invention has been described in detail with reference to the drawings and examples, but the present invention is not limited to the examples, and various changes can be made within the knowledge of those skilled in the art without departing from the spirit of the present invention. The prior art can be adopted in the content which is not described in detail in the invention.
Claims (8)
1. The utility model provides a long distance buries ground double-walled pipe inner tube leak source detection device which characterized in that includes: the device comprises a flow supply control device A, an interlayer pressurizing and pressure maintaining device B, a data acquisition and analysis device C, a pipeline to be detected (28), a plurality of transmission cables and a plurality of pressure-bearing hoses; the flow supply control device A is connected with the data acquisition and analysis device C through a transmission cable; one end of the detected pipeline (28) is connected with the flow supply control device A, and the other end of the detected pipeline (28) is connected with the data acquisition and analysis device C; an interlayer pressurizing and pressure maintaining device B is arranged at the interlayer of the pipeline (28) to be detected.
2. The device for detecting the leak source of the inner pipe of the long-distance buried double-wall pipe according to claim 1, is characterized in that: the flow control device a includes: the device comprises a compressed air source A (1), a pressure stabilizing tank (2), a pressure gauge (3), a flow regulating valve (4), a switch valve A (5), a switch valve B (6), a flow sensor (7), a dew point thermometer (8), a temperature sensor (9), a standard leak hole (10), a connecting flange (11) and a plurality of pressure-bearing hoses;
the compressed air source (1) is connected with one end of the pressure stabilizing tank (2) through a pressure-bearing hose, and the other end of the pressure stabilizing tank (2) is sequentially connected with a pressure gauge (3), a flow regulating valve (4), a switch valve A (5), a flow sensor (7), a dew point thermometer (8), a temperature sensor (9) and a connecting flange (11) in series through the pressure-bearing hose;
one end of the switch valve B (6) is arranged on a pressure-bearing hose between the flow regulating valve (4) and the switch valve A (5), and the other end of the switch valve B (6) is arranged on a pressure-bearing hose between the flow sensor (7) and the dew-point thermometer (8); a standard leak hole (10) is also arranged on the pressure-bearing hose between the temperature sensor (9) and the connecting flange (11);
the connecting flange (11) is connected to one end of the pipeline (28) to be detected.
3. The device for detecting the leak source of the inner pipe of the long-distance buried double-wall pipe according to claim 2, is characterized in that: the interlayer pressurizing and pressure maintaining device B comprises: the device comprises a helium gas source (12), a compressed air gas source B (13), a flowmeter B (14), a flowmeter C (15), a mixing pressure stabilizing tank (17), a helium concentration measuring instrument (16), an absolute pressure meter A (18), a pressure sensor (19), an absolute pressure meter B (20), a switch valve C (21), a switch valve D (22), a vacuum pump (23) and a plurality of pressure-bearing hoses; the device comprises a mixed pressure stabilizing tank (17), a helium gas source (12) and a compressed air source B (13) which are connected with each other through pressure-bearing hoses, wherein the mixed pressure stabilizing tank (17) is also connected with an interlayer of a detected pipeline (28) through the pressure-bearing hoses, and an absolute pressure meter A (18), a switch valve C (21), a pressure sensor (19), a switch valve D (22) and an absolute pressure meter B (20) are sequentially arranged on the pressure-bearing hoses between the mixed pressure stabilizing tank (17) and the interlayers of the detected pipeline (28); the switch valve D (22) is connected with a vacuum pump (23);
a flow meter B (14) is arranged on a pressure-bearing hose between the helium gas source (12) and the mixing pressure-stabilizing tank (17); and a flow meter C (15) is also arranged on the pressure-bearing hose between the compressed air source B (13) and the mixed pressure stabilizing tank (17).
4. The device for detecting the leak source of the inner pipe of the long-distance buried double-wall pipe according to claim 3, is characterized in that: the data acquisition and analysis device C further includes: a data acquisition computer (26), a helium mass spectrometer leak detector (25), a mass spectrometer suction gun (29), a connecting flange (24) and a current/digital converter (27); the current/digital converter (27) is respectively connected with the data acquisition computer (26) and the helium mass spectrometer leak detector (25) through transmission cables, and the helium mass spectrometer leak detector (25) is also connected with the mass spectrometer suction gun (29) through the transmission cables; the mass spectrometer suction gun (29) is provided with a connecting flange (24); the connecting flange (24) is connected with the other end of the pipeline (28) to be detected.
5. The device for detecting the leak source of the inner pipe of the long-distance buried double-wall pipe according to claim 4, is characterized in that: the current/digital converter (27) is also connected with the flow sensor (7) of the flow supply control device A through a transmission cable, and the current/digital converter (27) is also connected with the temperature sensor (9) of the flow supply control device A through a transmission cable.
6. The device for detecting the leak source of the inner pipe of the long-distance buried double-wall pipe according to claim 5, is characterized in that: the pressure-bearing hoses are all hard pressure-bearing hoses, and instrument pressure-leading pipe joints are arranged on the pressure-bearing pipelines.
7. The device for detecting the leak source of the inner pipe of the long-distance buried double-wall pipe according to claim 6, is characterized in that: pressure-bearing hose joints are arranged on the pressure stabilizing tank (2) and the mixed pressure stabilizing tank (17).
8. A detection and positioning method for the leak source detection device of the inner pipe of the long-distance buried double-wall pipe according to any one of claims 1 to 7 is characterized by comprising the following steps:
the method comprises the following steps: the flow supply control device A and the data acquisition and analysis device C are connected with a detected pipeline (28) through a connecting flange A (11) and a connecting flange B (24); a transmission cable is used for connecting the current/digital converter (27), the data acquisition computer (26) and the helium mass spectrometer leak detector (25), and power supplies are respectively introduced into the current/digital converter (27), the data acquisition computer (26) and the helium mass spectrometer leak detector (25), and a mass spectrometer suction gun (29) is placed at the outlet end of an inner pipe of a detected pipeline (28);
step two, inner tube initial inspection: opening a compressed air source A (1), closing a switch valve A (5) and a connecting flange (24), opening a switch valve B (6) and a flow regulating valve (4), and filling compressed air into an inner pipe of a detected pipeline (28), wherein the pressure of the compressed air is greater than 0.1 MPa; at the moment, the interlayer of the pipeline (28) to be detected keeps atmospheric pressure, and the leakage rate of the inner pipe of the pipeline (28) to be detected is measured after the pipeline is stabilized for four hours; selecting a proper reference leak hole to be arranged at the position of the standard leak hole (10);
step three, filling helium into the interlayer of the pipeline to be detected: closing the switch valve (21), opening the switch valve (22), and starting the vacuum pump (23) to vacuumize the interlayer of the pipeline to be detected; stopping the vacuum pump (23), opening the switch valve (21), closing the switch valve (22), opening the helium bottle (12) and the compressed air bottle (13), and filling a mixed gas of helium gas and air with a certain concentration into the interlayer; after the pressure is charged to a certain value, the switch valve (21) is closed;
step four, detection: open the switch valve A (5) andthe switch valve B (6) is closed, and the air flow of the inner pipe is adjusted to V by the flow transmitter (7)1(ii) a After the air flow rate is stable and the helium mass spectrometer leak detector signal is stable, adjusting the flow regulating valve to regulate the air flow rate to V2(ii) a If the leak exists, the helium concentration curves on the helium mass spectrometer leak detector (25) and the data acquisition computer (26) show obvious mutation, the mutation times represent the number of the leak, and the data acquisition computer (26) calculates the time T between the concentration change moment and the last concentration change moment of the helium mass spectrometer leak detector, the air temperature T, the pipeline section area S and the pipeline flow velocity V according to the time T, the air temperature T, the pipeline section area S and the pipeline flow velocity V2The distance between the leak point and the suction gun mouth of the mass spectrometer leak detector is calculated according to the parameters, and the formula for calculating the distance between the leak point and the suction gun mouth of the mass spectrometer leak detector is as follows (1):
where 273 is the fixed parameter value, i.e., kelvin temperature corresponding to 0 ℃.
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| CN116253075A (en) * | 2023-05-15 | 2023-06-13 | 常州远大新材料科技股份有限公司 | Cyanate ester mixture raw material storage tank for preparing plastering plate |
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| CN116253075A (en) * | 2023-05-15 | 2023-06-13 | 常州远大新材料科技股份有限公司 | Cyanate ester mixture raw material storage tank for preparing plastering plate |
| CN116253075B (en) * | 2023-05-15 | 2023-07-07 | 常州远大新材料科技股份有限公司 | Cyanate ester mixture raw material storage tank for preparing plastering plate |
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