CN117367953A - Full-size natural gas pipeline epoxy sleeve repairing effect evaluation method and system - Google Patents
Full-size natural gas pipeline epoxy sleeve repairing effect evaluation method and system Download PDFInfo
- Publication number
- CN117367953A CN117367953A CN202210759786.XA CN202210759786A CN117367953A CN 117367953 A CN117367953 A CN 117367953A CN 202210759786 A CN202210759786 A CN 202210759786A CN 117367953 A CN117367953 A CN 117367953A
- Authority
- CN
- China
- Prior art keywords
- pipeline
- test
- sleeve
- repair
- epoxy
- 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.)
- Pending
Links
- 239000004593 Epoxy Substances 0.000 title claims abstract description 97
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 title claims abstract description 79
- 230000000694 effects Effects 0.000 title claims abstract description 58
- 238000011156 evaluation Methods 0.000 title claims abstract description 35
- 239000003345 natural gas Substances 0.000 title claims abstract description 35
- 238000005452 bending Methods 0.000 claims abstract description 92
- 230000008439 repair process Effects 0.000 claims abstract description 76
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 53
- 239000010959 steel Substances 0.000 claims abstract description 53
- 230000007547 defect Effects 0.000 claims abstract description 47
- 230000009172 bursting Effects 0.000 claims abstract description 11
- 238000012360 testing method Methods 0.000 claims description 130
- 238000000034 method Methods 0.000 claims description 24
- 239000000463 material Substances 0.000 claims description 17
- 238000004880 explosion Methods 0.000 claims description 7
- 238000004458 analytical method Methods 0.000 claims description 5
- 230000009467 reduction Effects 0.000 claims description 5
- 238000012937 correction Methods 0.000 claims description 4
- 238000012795 verification Methods 0.000 abstract description 7
- 238000010276 construction Methods 0.000 abstract description 2
- 238000012216 screening Methods 0.000 abstract description 2
- 238000003466 welding Methods 0.000 description 16
- 238000001514 detection method Methods 0.000 description 14
- 230000002787 reinforcement Effects 0.000 description 11
- 229920000049 Carbon (fiber) Polymers 0.000 description 9
- 239000004917 carbon fiber Substances 0.000 description 9
- 238000013461 design Methods 0.000 description 9
- 238000013001 point bending Methods 0.000 description 9
- 239000000126 substance Substances 0.000 description 8
- 239000002131 composite material Substances 0.000 description 7
- 238000006073 displacement reaction Methods 0.000 description 7
- 238000005516 engineering process Methods 0.000 description 7
- 238000009864 tensile test Methods 0.000 description 7
- 238000004364 calculation method Methods 0.000 description 6
- 230000008569 process Effects 0.000 description 6
- 239000003209 petroleum derivative Substances 0.000 description 4
- 238000010998 test method Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 229920005989 resin Polymers 0.000 description 3
- 239000011347 resin Substances 0.000 description 3
- 230000001066 destructive effect Effects 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000007689 inspection Methods 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000009659 non-destructive testing Methods 0.000 description 2
- 230000035515 penetration Effects 0.000 description 2
- 238000011056 performance test Methods 0.000 description 2
- 238000003825 pressing Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000005422 blasting Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000005489 elastic deformation Effects 0.000 description 1
- 229920006335 epoxy glue Polymers 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000002657 fibrous material Substances 0.000 description 1
- 239000002737 fuel gas Substances 0.000 description 1
- 239000003292 glue Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000011900 installation process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 230000003014 reinforcing effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L5/00—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L5/00—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
- G01L5/14—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes for measuring the force of explosions; for measuring the energy of projectiles
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M13/00—Testing of machine parts
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/20—Investigating strength properties of solid materials by application of mechanical stress by applying steady bending forces
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
- G01N2203/06—Indicating or recording means; Sensing means
- G01N2203/067—Parameter measured for estimating the property
- G01N2203/0676—Force, weight, load, energy, speed or acceleration
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
The invention discloses a full-size natural gas pipeline epoxy sleeve repairing effect evaluation method and system, which take a pipeline to be repaired containing girth weld defects and an epoxy sleeve as an integral system to carry out verification evaluation, can quantitatively and operationally evaluate the repairing effect of the pipeline after sleeve repairing, compare data before and after repairing, and facilitate pipeline managers to quantitatively evaluate different epoxy sleeve repairing effects, thereby screening qualified products, improving repairing construction quality, prolonging service life of the pipeline containing the defects, and guaranteeing pipeline girth weld repairing safety. The lifting rate is obtained through axial stress, bursting failure pressure, hollow round tube polar moment of inertia and maximum bending moment, the comparison of the bearing parameters of the pipeline system before and after the pipeline is verified and repaired by the epoxy sleeve is quantitatively evaluated, and the problem of how to verify and compare the effectiveness and reliability of products when a pipeline manager applies the epoxy steel sleeve to repair the pipeline is solved.
Description
Technical Field
The invention belongs to the field of natural gas long-distance pipeline repair, and relates to a full-size natural gas pipeline epoxy sleeve repair effect evaluation method and system.
Background
The steel epoxy sleeve repairing technology is one kind of pipeline repairing technology and is mainly used in repairing the seam defect of petroleum and natural gas pipeline. The epoxy sleeve is mainly used for permanently repairing defects of various steel pipelines. Compared with the traditional repairing process of directly welding the steel sleeve to the outer wall of the steel pipe, the repairing of the epoxy sleeve is not tightly attached to the outer wall of the steel pipe, but is loosely sleeved on the pipeline, a certain annular gap is kept between the epoxy sleeve and the pipeline, two ends of the annular gap are sealed by glue, epoxy resin is poured into the sealed space to form a composite sleeve, and after the filling material is solidified, the composite sleeve and the external sleeve act together to transfer stress, so that the repairing effect of defect reinforcement is achieved, and the defect of the pipeline is reinforced. The epoxy steel sleeve repairing technology does not need to stop transportation and directly fire on the pipe wall, so that the risks of welding penetration, welding cracks and the like caused by fire do not exist, and the epoxy steel sleeve repairing technology is favored by pipeline managers in recent years. The epoxy sleeve has the advantages that: the method has the advantages of no need of pressure reduction and transportation stop, pressure restoration, strong flexibility and the like.
The main idea of the technology for repairing and reinforcing the steel pipeline by using the composite material is to recover the service strength of the pipeline containing the defects by using the high strength characteristic of the fiber material in the fiber direction and coating a composite material repairing pipeline layer outside the service pipeline by using bonding resin. The method has the advantages that welding is not needed on the service pipeline, and the risks of welding penetration and hydrogen embrittlement and cold embrittlement are avoided. Composite reinforcement technology has become a widely accepted reinforcement technology for various pipe companies.
In recent years, the quality problem of the girth weld of the large-caliber main pipeline becomes a great problem affecting the safe operation of the pipeline, and the epoxy sleeve repair is widely applied to the field of girth weld defect repair of the large-caliber main pipeline as an effective repair mode.
The existing epoxy steel sleeve products only carry out appearance quality detection, sleeve wall thickness detection, sleeve plate splicing weld joint nondestructive detection, geometric dimension (outer diameter, length, ovality) measurement, resin filling cavity detection in sleeve installation stage, installation clearance detection, pipe surface anchor line processing detection and other performance detection on the epoxy steel sleeve according to the requirements of an epoxy steel sleeve production process, the epoxy steel sleeve is lack of full-size repair verification test to verify the repair effect of the epoxy steel sleeve, the patent 201910901482.0 'an evaluation method for repairing a pipeline effect by using the epoxy steel sleeve' describes general quality detection evaluation of the epoxy steel sleeve manufacturing and installation process mainly based on nondestructive detection, a test device for repairing the whole bearing capacity of a pipe after repairing the epoxy steel sleeve, ZL201410691341.8 'a full-size four-point bending test platform for a natural gas pipe and an experiment method thereof' only design a full-size four-point bending test platform for a fuel gas pipeline performance life test item, and other verification test methods for repairing the epoxy sleeve are not described. The prior art adopts a hydraulic blasting mode to verify the bearing capacity of the epoxy sleeve, but the method is inconsistent with the actual in-service working condition of the pipeline, and cannot truly reflect the in-service bearing capacity of the epoxy sleeve.
An important basic work for repairing the girth weld of the sleeve is as follows: and determining the repair effectiveness of the sleeve according to theoretical and numerical simulation calculation, and performing physical verification of the sleeve repair effectiveness. The verification must be carried out under the composite loading conditions of internal pressure, axial load, internal pressure, bending and the like, so that the application range and the repairing effect of the device can be accurately defined. The test capability is limited, and the current method for verifying the repair effect of the epoxy sleeve of the large-caliber pipeline is not reported, so that new problems are brought to the safe operation and the integrity management of the in-service pipeline. Therefore, verification of the capability of repairing the circumferential weld of the epoxy sleeve under the typical working condition is carried out, so that the repairing effect of the epoxy sleeve is clear, the applicable defect type and geological working condition are pointed out, the repairing effect is determined, and the safety accident caused by hidden danger due to blind use is avoided. At present, a pipeline manager does not have clear knowledge on the performance, quality, repair effect and service state of the epoxy sleeve after repair, and no specific repair effect inspection method exists.
Disclosure of Invention
The invention aims to solve the problem that a pipeline manager cannot verify and compare the effectiveness and reliability of a product when an epoxy steel sleeve is applied to repair a pipeline in the prior art, and provides a full-size natural gas pipeline epoxy sleeve repair effect evaluation method and system.
In order to achieve the purpose, the invention is realized by adopting the following technical scheme:
the invention provides a full-size natural gas pipeline epoxy sleeve repairing effect evaluation method, which comprises the following steps:
analyzing the axial bearing capacity of the test pipeline containing the girth weld defect and the repaired test pipeline to obtain axial stress;
analyzing bending resistance bearing capacity of the test pipeline containing the girth weld defect and the repaired test pipeline to obtain bursting failure pressure, hollow round pipe polar moment of inertia and maximum bending moment;
according to the axial stress, the bursting failure pressure, the polar moment of inertia of the hollow circular tube and the maximum bending moment, the load lifting rate of the test pipeline before repair and the test pipeline section after repair is obtained, and the repair effect evaluation of the epoxy sleeve is realized.
Preferably, the axial stress δ is calculated as follows:
δ＝KF/S (1)
wherein K is a correction coefficient; s is the sectional area of the steel pipe; f is axial loading.
Preferably, the burst failure pressure P c0 Is calculated as follows:
wherein ζ is a failure pressure reduction coefficient; t is the wall thickness of the pipeline, and the unit is mm; d is the outer diameter of the pipeline, and the unit is mm; sigma (sigma) u Is the tensile ultimate strength of the material; sigma (sigma) y Is the yield strength of the material.
Preferably, the hollow round tube polar moment of inertia I is calculated as follows:
wherein D is the outer diameter of the pipeline, and the unit is mm; c is the ratio of the inner diameter to the outer diameter.
Preferably, the test tube is subjected to a maximum bending moment sigma max The following are provided:
wherein W is a bending-resistant section coefficient, and the unit is m 3 The method comprises the steps of carrying out a first treatment on the surface of the M is the bending moment born by the test sample, and the unit is kN.m.
Preferably, the maximum bending moment sigma that the test tube can be loaded max And if the yield strength value is larger than the pipe yield strength value, the test pipeline is bent and fails.
Preferably, the bending section modulus W and the bending moment M to which the specimen is subjected are expressed as follows:
wherein D is the outer diameter of the pipeline, and the unit is mm; c is the ratio of the inner diameter to the outer diameter;
M＝Fa (6)
wherein F is a bending load; a is a moment arm, and the unit is m.
Preferably, the deflection value w at the middle of the pipeline is obtained according to the bending moment M born by the test sample and the polar inertia moment I of the hollow round tube, and the bending resistance bearing capacity analysis of the epoxy steel sleeve is refined, wherein the expression is as follows:
wherein E is the elastic coefficient.
Preferably, the expression of the lift rate is as follows:
wherein, the lifting rate is in direct proportion to the effect after repair.
The invention provides a full-size natural gas pipeline epoxy sleeve repairing effect evaluation system, which comprises the following components:
the axial load parameter acquisition module is used for analyzing the axial bearing capacity of the test pipeline containing the girth weld defect and the repaired test pipeline and acquiring the axial stress;
the bending load parameter acquisition module is used for analyzing bending load bearing capacity of the test pipeline containing the girth weld defect and the repaired test pipeline and acquiring explosion failure pressure, hollow round pipe polar moment of inertia and maximum bending moment;
the sleeve repair evaluation module is used for acquiring load lifting rates of the test pipeline before repair and the test pipeline section after repair according to axial stress, explosion failure pressure, hollow round pipe polar moment of inertia and maximum bending moment, and realizing repair effect evaluation of the epoxy sleeve.
Compared with the prior art, the invention has the following beneficial effects:
the invention provides a full-size natural gas pipeline epoxy sleeve repairing effect evaluation method, which takes a test pipeline containing girth weld defects and an epoxy sleeve as an integral system to carry out verification and evaluation so as to effectively verify the comparison of bearing parameters of the pipeline system before and after the test pipeline is repaired by the epoxy sleeve, quantitatively evaluate the epoxy sleeve repairing effect and solve the problems of verifying and comparing the effectiveness and the reliability of products when a pipeline manager applies an epoxy steel sleeve to repair the pipeline. Specifically, the invention designs the girth weld for the test pipeline, so that one group of pipe sections do not repair, the other group of pipe sections adopt a repair mode of combining a steel epoxy sleeve and carbon fiber reinforcement, bending load and axial load are respectively applied, and parameters such as bending moment, curvature, strain and the like are collected for analysis, and the repair effect of the epoxy sleeve is compared, so that the stress load state of the in-service pipeline is better and more truly simulated. The method solves the problems of how to quantitatively evaluate the safety, the effectiveness and the reliability of the repaired pipeline system when the pipeline manager applies the epoxy steel sleeve to repair the natural gas pipeline, compares the repair differences of various epoxy steel sleeves, selects proper products and ensures the safe and reliable operation of the pipeline repaired by the epoxy sleeve. The lifting rate is obtained through axial stress, bursting failure pressure, hollow round tube polar moment of inertia and maximum bending moment, the comparison of the bearing parameters of the pipeline system before and after the pipeline is verified and repaired by the epoxy sleeve is quantitatively evaluated, and the problem of how to verify and compare the effectiveness and reliability of products when a pipeline manager applies the epoxy steel sleeve to repair the pipeline is solved. The invention compares the data before and after repair, and is convenient for a pipeline manager to quantitatively evaluate the repair effects of different epoxy sleeves, thereby screening qualified products, improving the repair construction quality, prolonging the service life of the pipeline defect, guaranteeing the repair safety of the pipeline girth weld and achieving the purpose of improving the management level of the integrity of the pipeline. Therefore, the evaluation method provided by the invention is used for evaluating the repair effect of the epoxy sleeve for repairing the pipeline containing the girth weld defect, so that the comparison of the bearing parameters of the pipeline system before and after the repair of the epoxy sleeve is effectively verified, the repair effect of the epoxy sleeve is quantitatively evaluated, and the problems of how to verify and compare the effectiveness and the reliability of the product when a pipeline manager applies the epoxy steel sleeve to repair the pipeline are solved.
Further, by means of prefabricating the girth weld defects, the possibility of implementing the test under the condition of insufficient equipment capacity is achieved, and the test difficulty is reduced.
According to the full-size natural gas pipeline epoxy sleeve repairing effect evaluation system, the system is divided into the axial load parameter acquisition module, the bending load parameter acquisition module and the sleeve repairing evaluation module, and the modules are mutually independent by adopting a modularized idea, so that unified management of the modules is facilitated.
Drawings
For a clearer description of the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present invention and should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a flow chart of a method for evaluating the repair effect of an epoxy sleeve of a full-size natural gas pipeline.
Fig. 2 is a diagram of an evaluation system for repairing effect of an epoxy sleeve of a full-size natural gas pipeline.
Fig. 3 is a schematic overall flow chart of an evaluation method for repairing effect of the full-size natural gas pipeline epoxy sleeve.
FIG. 4 is a schematic representation of a four-point bending moment of the present invention.
FIG. 5 is a diagram of a bending 1-1 strain testing arrangement of the present invention.
FIG. 6 is the bending 1-2 strain test arrangement of the present invention FIG. 1.
FIG. 7 is the bending 1-2 strain test arrangement of the present invention FIG. 2.
FIG. 8 is a diagram of a tensile 2-1 strain test arrangement according to the present invention.
FIG. 9 is a drawing 2-2 strain test arrangement of the present invention FIG. 1.
FIG. 10 is a drawing 2-2 strain test arrangement of the present invention FIG. 2.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.
In the description of the embodiments of the present invention, it should be noted that, if the terms "upper," "lower," "horizontal," "inner," and the like indicate an azimuth or a positional relationship based on the azimuth or the positional relationship shown in the drawings, or the azimuth or the positional relationship in which the inventive product is conventionally put in use, it is merely for convenience of describing the present invention and simplifying the description, and does not indicate or imply that the apparatus or element to be referred to must have a specific azimuth, be configured and operated in a specific azimuth, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like, are used merely to distinguish between descriptions and should not be construed as indicating or implying relative importance.
Furthermore, the term "horizontal" if present does not mean that the component is required to be absolutely horizontal, but may be slightly inclined. As "horizontal" merely means that its direction is more horizontal than "vertical", and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.
In the description of the embodiments of the present invention, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed," "mounted," "connected," and "connected" should be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.
The invention is described in further detail below with reference to the attached drawing figures:
the invention provides a full-size natural gas pipeline epoxy sleeve repairing effect evaluation method, which is shown in fig. 1 and comprises the following steps:
s1, analyzing axial bearing capacity of a test pipeline containing girth weld defects and a repaired test pipeline to obtain axial stress;
the axial stress delta is calculated as follows:
δ＝KF/S (1)
wherein K is a correction coefficient; s is the sectional area of the steel pipe; f is axial loading.
S2, carrying out bending resistance bearing capacity analysis on the test pipeline containing the girth weld defect and the repaired test pipeline, and obtaining explosion failure pressure, hollow round pipe polar moment of inertia and maximum bending moment;
the burst failure pressure P c0 Is calculated as follows:
wherein ζ is a failure pressure reduction coefficient; t is the wall thickness of the pipeline, and the unit is mm; d is the outer diameter of the pipeline, and the unit is mm; sigma (sigma) u Is the tensile ultimate strength of the material; sigma (sigma) y Is the yield strength of the material.
The hollow round tube polar moment of inertia I is calculated as follows:
wherein D is the outer diameter of the pipeline, and the unit is mm; c is the ratio of the inner diameter to the outer diameter.
Maximum bending moment sigma born by test pipeline max The following are provided:
wherein W is a bending-resistant section coefficient, and the unit is m 3 The method comprises the steps of carrying out a first treatment on the surface of the M is the bending moment born by the test sample, and the unit is kN.m.
Maximum bending moment sigma capable of being loaded by test pipeline max And if the yield strength value is larger than the pipe yield strength value, the test pipeline is bent and fails.
The bending section modulus W and the bending moment M to which the specimen is subjected are expressed as follows:
wherein D is the outer diameter of the pipeline, and the unit is mm; c is the ratio of the inner diameter to the outer diameter;
M＝Fa (6)
wherein F is a bending load; a is a moment arm, and the unit is m.
According to the bending moment M born by the test sample and the polar inertia moment I of the hollow round tube, the deflection value w at the middle of the pipeline is obtained, and the bending resistance bearing capacity analysis of the epoxy steel sleeve is refined, wherein the expression is as follows:
wherein E is the elastic coefficient.
And S3, acquiring the load lifting rate of the test pipeline before repair and the test pipeline section after repair according to the axial stress, the bursting failure pressure, the polar moment of inertia of the hollow circular pipe and the maximum bending moment, and realizing the repair effect evaluation of the epoxy sleeve.
The expression of the lift rate is as follows:
wherein, the lifting rate is in direct proportion to the effect after repair.
The invention provides a full-size natural gas pipeline epoxy sleeve repairing effect evaluation system, as shown in fig. 2, comprising:
the axial load parameter acquisition module is used for analyzing the axial bearing capacity of the test pipeline containing the girth weld defect and the repaired test pipeline and acquiring the axial stress;
the bending load parameter acquisition module is used for analyzing bending load bearing capacity of the test pipeline containing the girth weld defect and the repaired test pipeline and acquiring explosion failure pressure, hollow round pipe polar moment of inertia and maximum bending moment;
the sleeve repair evaluation module is used for acquiring load lifting rates of the test pipeline before repair and the test pipeline section after repair according to axial stress, explosion failure pressure, hollow round pipe polar moment of inertia and maximum bending moment, and realizing repair effect evaluation of the epoxy sleeve.
The invention provides a full-size natural gas pipeline epoxy sleeve repairing effect evaluation method, which specifically comprises the following steps:
step one, selecting a sample: test tube sections are selected, including tube section geometry, tube section materials, and tube section manufacturing criteria. For comparability of the test, the test tube sections used should be the same lot number tube sections of the same manufacturer.
Step two, physical and chemical performance test of the same batch pipe section for test: the natural gas pipeline testing device comprises chemical components, tensile properties (the yield strength and the tensile strength of the natural gas pipeline to be tested are obtained through tensile property testing), impact toughness, drop weight tearing, weld joint guiding bending, vickers hardness and metallographic phase. The test results should meet the requirements of the pipeline section standard for the transportation of the petroleum and natural gas industry pipelines, otherwise, pipeline section samples of other batches should be reselected.
Step three, designing the length of the test tube section: the ratio of the diameter to the length of the four-point bending test tube section is required to be less than 0.1, and the ratio of the diameter to the length of the axial tensile test sample is required to be less than 0.2. The welding process adopts original pipe section design parameters to ensure the comparability of the test pipe section. In order to detect physical and chemical properties (destructive detection) of the welded girth weld, girth welds for physical and chemical property tests are designed to be welded by using the same welding process and the same lot number pipeline.
And fourthly, welding according to the welding design scheme of the circumferential weld assembly of the test pipeline, performing X-ray detection and ultrasonic detection on all the circumferential welds, and if no, repairing until no exceeding defect exists, wherein the repairing times are not more than 2.
Step five, physical and chemical performance testing is carried out on the girth weld in the step three: the method comprises a tensile test, a bending test and grooving hammer breaking, wherein the test result meets the welding and acceptance requirements of steel pipelines, and otherwise, the welding girth welds are reorganized.
And step six, respectively carrying out an axial bearing capacity test design of the epoxy steel sleeve and a bending resistance bearing capacity test design of the epoxy steel sleeve.
The axial bearing capacity test design of the epoxy steel sleeve comprises 1 group of comparison tests, a conveying test pipeline with a large caliber of X70 is adopted, girth weld defects with the same length and depth are prefabricated, the length of the test pipeline meets the requirement of the step 3, one test pipeline is not repaired, the other test pipeline adopts a repairing mode of combining the steel epoxy sleeve with carbon fiber reinforcement, and internal pressure and axial load are applied.
2 factors mainly considered in the selection of girth weld defect sizes for axial bearing capacity tests:
1) Under the condition of no sleeve, the tensile test pipeline does not fail under the working pressure of the pipeline. Thereby determining the defect upper limit size.
2) When the internal pressure and the axial load are carried out without the sleeve, the pipe section after the processing defect is in failure in the equipment capacity range (load and working distance). Thereby determining the defect lower limit size.
The bending-resistant bearing capacity test design of the epoxy steel sleeve comprises 1 group of comparison tests, a conveying pipeline with a large caliber X70 is adopted, girth weld defects with the same length and depth are prefabricated, the length of the test pipeline meets the requirement of the step 3, one test pipeline is not repaired, the other test pipeline adopts a repairing mode of combining the steel epoxy sleeve with carbon fiber reinforcement, and internal pressure and bending load are applied.
2 factors mainly considered in girth weld defect size selection for bending resistance bearing capacity test:
1) Under the condition of no sleeve, the bending sample does not fail under the working pressure of the pipeline. Thereby determining the defect upper limit size.
2) When the internal pressure and the bending load are applied without the sleeve, the pipe section after the processing defect fails within the equipment capacity range (load and working distance). Thereby determining the defect lower limit size.
Step seven, axial stretching bearing capacity test calculation, namely calculating axial stress according to the geometric size of the defect, wherein the axial stress is calculated as follows:
δ＝KF/S
wherein K is a correction coefficient; delta is the axial stress; s is the sectional area of the pipeline; f is axial loading.
And (3) calculating to obtain the axial stress delta, and comparing the axial stress delta with the yield strength value of the pipe in the second step, if the axial stress delta is larger than the yield strength value of the pipe.
Bending resistance bearing capacity test calculation, namely calculating bursting failure pressure P according to the geometric size of the defect c0 The calculation formula is as follows:
wherein ζ is a failure pressure reduction coefficient; t is the wall thickness of the pipeline, and the unit is mm; d is the outer diameter of the pipeline, and the unit is mm; sigma (sigma) u Is the tensile ultimate strength of the material; sigma (sigma) y Is the yield strength of the material. Calculating the bursting failure pressure P of the test pipeline c0 For the test pipeline without the protection of the epoxy sleeve, the damage phenomenon of the bending test pipeline can not occur when the test pipeline is loaded to normal working pressure.
To the bending test pipeline, the polar moment of inertia I of the hollow circular pipe of the pipeline, the bending resistance section coefficient W and the maximum bending moment sigma capable of being loaded by the testing machine are required to be calculated max ：
M＝Fa
Wherein I is polar moment of inertia, and the unit is m 4 The method comprises the steps of carrying out a first treatment on the surface of the D is the outer diameter of the pipeline, and the unit is mm; c is the ratio of the inner diameter to the outer diameter; w is the bending-resistant section coefficient, and the unit is m 3 The method comprises the steps of carrying out a first treatment on the surface of the M is the bending moment born by the sample, and the unit is kN.m; f is bending load, kN is maximum loading load is equipment capacity limit; a is a moment arm, and the unit is m.
And (3) calculating to obtain: polar inertia distance I, bending resistance section coefficient W, bending moment M, maximum bending moment sigma capable of being loaded by test pipeline max 。
According to the yield strength value of the pipe obtained in the second step and the maximum bending moment sigma capable of being loaded by the testing machine max Comparing, if the maximum bending moment sigma of the tester can be loaded max Greater than the tubing yield strength value, the maximum loading capacity of the test tubing is indicative of tubing bending failure.
Then calculating the deflection value w at the middle of the pipeline,
and comparing the calculated deflection value w with the maximum actuating distance of the actuating cylinder, wherein the deflection value at the middle of the pipeline is smaller than the maximum actuating distance of the actuating cylinder.
Step eight, designing an epoxy sleeve repairing scheme according to pipeline parameters, adopting a repairing mode of combining an epoxy steel sleeve with carbon fiber reinforcement, and arranging the following steps: firstly, treating the surface of a pipeline to be repaired, then carrying out carbon fiber composite material reinforcement work, then installing a steel epoxy sleeve, then carrying out sleeve end sealing, then carrying out negative pressure filling epoxy glue filling, finally carrying out quality inspection, wherein the detection content comprises a repairing material per se and three parts including sleeve material performance, carbon fiber performance and resin filling material performance, and continuing to carry out subsequent work after the repairing material per se is qualified.
Step nine, designing a step of testing strain gauges, wherein the strain gauge arrangement positions at least comprise artificial defect positions (comprising front ends, middle ends and rear ends of cracks), the strain gauges are circumferentially arranged at intervals of 90 degrees, and in order to facilitate comparison of stress changes before and after repair, the strain gauges are arranged at the same positions, so that comparison is facilitated. In consideration of the effect before and after the repair of the epoxy sleeve, strain gauges are distributed at the same positions inside and outside the epoxy sleeve, so that the strain gauges are compared with the control.
Step ten, as shown in fig. 4, the four-point bending test method is used for testing the maximum working pressure of the pipeline, X70 steel is adopted, in the test process, the bending torch loading is realized by pushing the pipeline through 2 hydraulic cylinders, and the four-point bending test in a similar mechanical experiment is shown in fig. 4, and has the advantages of ensuring that the pipeline between 2 hydraulic cylinders is in an approximately pure bending state, namely, the shearing force of the pipeline in the section in the test is very small and negligible. The bending moment is calculated by hydraulic thrust and a moment arm. The internal pressure loading of the pipeline is realized by a numerical control hydraulic system.
The large-caliber conveying steel pipe is adopted, girth weld defects with the same length and depth are prefabricated, one pipe section is not repaired, the other pipe section is repaired by combining a steel epoxy sleeve with carbon fiber reinforcement, and internal pressure plus four-point bending load is applied.
Step eleven, an axial tensile test, namely prefabricating girth weld defects with the same length and depth by adopting a large-caliber conveying steel pipe, so that one pipe section does not repair, and the other pipe section adopts a repairing mode of combining a steel epoxy sleeve and carbon fiber reinforcement, and internal pressure and axial load are applied.
And step twelve, taking the lifting amount, the displacement increment and the sleeve bearing stress amount of the repaired load as indexes for evaluating the repairing effect, and quantitatively evaluating the repairing effect of the sleeve. The judgment standard of the repair effect adopts the comparison of the test data of the same group to calculate the lifting rate.
And taking the lifting rate of the load after repair, the displacement lifting rate and the sleeve bearing strain lifting rate as indexes for evaluating the repair effect, and quantitatively evaluating the repair effect of the sleeve.
The invention adopts a conveying steel pipe with the same furnace batch number and large caliber 1016mm X70, and checks the physicochemical properties of a pipe sample according to a certain standard, wherein the conveying steel pipe comprises chemical components, tensile properties, impact toughness, drop hammer tearing, weld joint guiding bending, vickers hardness and metallographic phase. The test result meets the requirements of the steel pipe standard for the pipeline transportation of the petroleum and natural gas industry.
Girth weld assembly welding and flaw detection:
designing 5 girth welds, wherein 1 is a destructive girth weld physical and chemical property test, and the other 4 is a girth weld for test, and welding according to a certain welding technological rule. And after the welding is finished, carrying out nondestructive testing on the girth weld according to nondestructive testing standards of a certain petroleum and natural gas steel pipeline, wherein all girth weld has no exceeding defect.
And the main physical and chemical performance test of the girth weld comprises a tensile test, a bending test and a grooving hammer breaking test, and the result meets the welding and acceptance requirements of a certain steel pipeline.
Prefabricating artificial defects:
in order to compare the bearing capacity of the repaired epoxy steel sleeve with the defect girth weld, two groups of steel pipes with the same specification and the same material are selected, and the steel pipes with the defects of the same size are prefabricated for load research, and the results shown in fig. 5 to 10 are obtained according to the following table.
The seventh step of adopting the invention content is to calculate:
bending test calculation result: calculating the bursting pressure P of the pipeline c0 For a comparison pipeline which is not protected by an epoxy sleeve, the bending of the pipeline is 1-1 at 20.88Mpa, and the pipeline damage phenomenon can not occur when the pipeline is loaded to the working pressure of 10 Mpa. Calculated i=0.00679 m4, w=0.01334 m3, m=11040 kn.m. The yield strength of the X70 material is 485Mpa, and the load value corresponding to 485Mpa stress is 141.3t for the elastic deformation stage before yielding. The deflection at the middle part is 63.8mm, the distance at the actuating cylinder is 50mm, and the four-point bending equipment capacity is met.
Axial tensile load bearing capacity test calculation: for a prefabricated crack pipe body (the outer diameter D=1016 mm and the residual wall thickness t0=4.374 mm), the maximum stress obtained by loading the tester is 1438.2Mpa, and the yield strength is 485Mpa larger than the yield limit of the material; and repairing the girth joint artificial defect by adopting a repairing mode combining an epoxy steel sleeve and carbon fiber reinforcement, and detecting the girth joint artificial defect to be qualified.
2 bending tests were performed: and (3) installing a bending test, namely injecting water into the pipeline, pressing the pipeline to the pipeline working pressure, applying bending load, and continuously reading the applied load, strain data, displacement data and the internal pressure of the pipeline in the bending load applying process, wherein when the internal pressure or the load data suddenly drops or, the test piece is damaged, and the test is ended.
2 axial tensile tests were performed: and (3) installing a tensile sample, namely filling water into the pipeline, pressing the pipeline to the pipeline working pressure, applying a tensile load, and reading the applied load, strain data, displacement data and the internal pressure of the pipeline in the tensile load applying process, wherein when the internal pressure or the load data suddenly drops or, the test piece is damaged, and the test is ended.
The data were analyzed. The four-point bending test method is compared to repair the change amounts of load, bending moment, load-curvature, load-strain and curvature-strain before and after the repair; and comparing the load-displacement, load-strain and displacement-strain variation before and after the axial tensile test repair. And taking the lifting amount, the displacement increment and the sleeve bearing stress amount of the repaired load as indexes for evaluating the repairing effect, and quantitatively evaluating the repairing effect of the sleeve.
By adopting the test method, the in-service stress condition of the pipeline when the circumferential weld of the natural gas pipeline is subjected to bending load or axial displacement load after being repaired by the epoxy sleeve can be simulated, and the aim of verifying and evaluating the repair capacity of the epoxy sleeve is realized through the comparative test design.
The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. The full-size natural gas pipeline epoxy sleeve repairing effect evaluation method is characterized by comprising the following steps of:
analyzing the axial bearing capacity of the test pipeline containing the girth weld defect and the repaired test pipeline to obtain axial stress;
analyzing bending resistance bearing capacity of the test pipeline containing the girth weld defect and the repaired test pipeline to obtain bursting failure pressure, hollow round pipe polar moment of inertia and maximum bending moment;
according to the axial stress, the bursting failure pressure, the polar moment of inertia of the hollow circular tube and the maximum bending moment, the load lifting rate of the test pipeline before repair and the test pipeline section after repair is obtained, and the repair effect evaluation of the epoxy sleeve is realized.
2. The full-size natural gas pipeline epoxy sleeve repair effect evaluation method according to claim 1, wherein the axial stress delta is calculated as follows:
δ＝KF/S (1)
wherein K is a correction coefficient; s is the sectional area of the steel pipe; f is axial loading.
3. The full-size natural gas pipeline epoxy sleeve repair effect evaluation method according to claim 1, wherein the bursting failure pressure P c0 Is calculated as follows:
wherein ζ is a failure pressure reduction coefficient; t is the wall thickness of the pipeline, and the unit is mm; d is the outer diameter of the pipeline, and the unit is mm; sigma (sigma) u Is the tensile ultimate strength of the material; sigma (sigma) y Is the yield strength of the material.
4. The full-size natural gas pipeline epoxy sleeve repair effect evaluation method according to claim 1, wherein the hollow circular tube polar moment of inertia I is calculated as follows:
wherein D is the outer diameter of the pipeline, and the unit is mm; c is the ratio of the inner diameter to the outer diameter.
5. Full-size natural gas pipeline epoxy sleeve repair effect assessment according to claim 1The method is characterized in that the maximum bending moment sigma born by the test pipeline max The following are provided:
wherein W is a bending-resistant section coefficient, and the unit is m 3 The method comprises the steps of carrying out a first treatment on the surface of the M is the bending moment born by the test sample, and the unit is kN.m.
6. The method for evaluating the repair effect of the epoxy sleeve of the full-size natural gas pipeline according to claim 5, wherein the maximum bending moment sigma capable of being loaded by the test pipeline is max And if the yield strength value is larger than the pipe yield strength value, the test pipeline is bent and fails.
7. The method for evaluating the repair effect of the epoxy sleeve of the full-size natural gas pipeline according to claim 5, wherein the bending resistance section coefficient W and the bending moment M born by the test sample are expressed as follows:
wherein D is the outer diameter of the pipeline, and the unit is mm; c is the ratio of the inner diameter to the outer diameter;
M＝Fa (6)
wherein F is a bending load; a is a moment arm, and the unit is m.
8. The method for evaluating the repair effect of the epoxy sleeve of the full-size natural gas pipeline according to claim 7, wherein the deflection value w at the middle of the pipeline is obtained according to the bending moment M born by the test sample and the polar moment I of the hollow round pipe, and the analysis of the bending resistance bearing capacity of the epoxy steel sleeve is refined, wherein the expression is as follows:
wherein E is the elastic coefficient.
9. The full-size natural gas pipeline epoxy sleeve repair effect evaluation method according to claim 1, wherein the expression of the lifting rate is as follows:
wherein, the lifting rate is in direct proportion to the effect after repair.
10. Full-size natural gas pipeline epoxy sleeve repair effect evaluation system, characterized by comprising:
the axial load parameter acquisition module is used for analyzing the axial bearing capacity of the test pipeline containing the girth weld defect and the repaired test pipeline and acquiring the axial stress;
the bending load parameter acquisition module is used for analyzing bending load bearing capacity of the test pipeline containing the girth weld defect and the repaired test pipeline and acquiring explosion failure pressure, hollow round pipe polar moment of inertia and maximum bending moment;
the sleeve repair evaluation module is used for acquiring load lifting rates of the test pipeline before repair and the test pipeline section after repair according to axial stress, explosion failure pressure, hollow round pipe polar moment of inertia and maximum bending moment, and realizing repair effect evaluation of the epoxy sleeve.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210759786.XA CN117367953A (en) | 2022-06-30 | 2022-06-30 | Full-size natural gas pipeline epoxy sleeve repairing effect evaluation method and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210759786.XA CN117367953A (en) | 2022-06-30 | 2022-06-30 | Full-size natural gas pipeline epoxy sleeve repairing effect evaluation method and system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117367953A true CN117367953A (en) | 2024-01-09 |
Family
ID=89391508
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210759786.XA Pending CN117367953A (en) | 2022-06-30 | 2022-06-30 | Full-size natural gas pipeline epoxy sleeve repairing effect evaluation method and system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117367953A (en) |
-
2022
- 2022-06-30 CN CN202210759786.XA patent/CN117367953A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| George et al. | Experimental and numerical investigation of underwater composite repair with fibre reinforced polymers in corroded tubular offshore structural members under concentric and eccentric axial loads | |
| Benjamin et al. | Burst tests on pipeline with long external corrosion | |
| CN111929147B (en) | B-type sleeve bearing capacity inspection method for repairing circumferential weld defects of oil and gas pipeline | |
| Chapetti et al. | Full scale experimental analysis of stress states in sleeve repairs of gas pipelines | |
| Otegui et al. | Weld failures in sleeve reinforcements of pipelines | |
| Wang et al. | Strain based design of high strength pipelines | |
| CN117367953A (en) | Full-size natural gas pipeline epoxy sleeve repairing effect evaluation method and system | |
| MIHAIL et al. | Experimental stand for internal pressure testing of pipes | |
| Glover et al. | Technology approaches for northern pipeline developments | |
| Benjamin et al. | Burst tests on pipeline with nonuniform depth corrosion defects | |
| Bastola et al. | Full-and small-scale tests on strain capacity of X80 seamless pipes | |
| Trajković et al. | Additively manufactured tensile ring-shaped specimens for pipeline material fracture examination-influence of geometry | |
| Ren et al. | Study on the Effect of Material Characteristic on the Limit Pressure of the Pipeline Girth Weld Containing Welding Defect | |
| Zimmerman et al. | Composite reinforced line pipe (CRLP) for onshore gas pipelines | |
| Leis et al. | STEP IMPROVEMENTS IN METAL-LOSS ASSESSMENT CRITIRIA FOR PIPELINES | |
| Wang et al. | Verification Analysis of X70 Type B Sleeve for In-service Pipeline Repair | |
| Sedmak et al. | An experimental investigation into the operational safety of a welded penstock by a fracture mechanics approach | |
| Höhler et al. | Influence of material heterogeneity on the strain capacity of pipelines | |
| Eadie et al. | Long seam welds in gas and liquids pipelines and near-neutral pH stress corrosion cracking and corrosion fatigue | |
| Rafi et al. | Strength of line pipe with dent and crack defect | |
| Wang et al. | Development of a FAD-Based Girth Weld ECA Procedure: Part II—Experimental Verification | |
| Chantz Denowh | Use of Full-scale Testing as a Means for Managing Pipeline Integrity | |
| Sedmak et al. | The applicability of strategy for risk based maintenance to a penstock | |
| Grabulov et al. | Structural integrity assessment of pressure vessels with defect in welded joints | |
| Abtahi et al. | Experimental and Finite Element Analysis of Corroded High-Pressure Pipeline Repaired by Laminated Composite. |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |