CN103363919A - Device and method for measuring strain of high-temperature pipeline of power plant based on white light speckle technology - Google Patents
Device and method for measuring strain of high-temperature pipeline of power plant based on white light speckle technology Download PDFInfo
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- CN103363919A CN103363919A CN2013102941664A CN201310294166A CN103363919A CN 103363919 A CN103363919 A CN 103363919A CN 2013102941664 A CN2013102941664 A CN 2013102941664A CN 201310294166 A CN201310294166 A CN 201310294166A CN 103363919 A CN103363919 A CN 103363919A
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Abstract
The invention relates to the field of near-line strain monitoring of high-temperature high-pressure metal components, in particular to a device and method for utilizing the white light speckle correlation technology to monitor the strain of the high-temperature components of a power plant in a non-contact and near-line mode. The device comprises a locating substrate (2), a strain sensor (3) and a fixed focus camera (4). According to the device and method, creep damage conditions of the high-temperature metal components, operated at high temperature for a long time, of the power plant can be accurately monitored, and the production accidents caused by failures and damage of the components due to high-temperature creep are avoided. In order to evaluate the service life of equipment, the creep strain of the high-temperature metal components of the power plant is monitored, creep strain accumulation measured values are utilized to conduct service life evaluation, so that the evaluation result is prevented from being too conservative, and the service life of the equipment is prolonged. Overhauling time of the equipment of the power plant can be determined according to the creep strain result, and the state of the equipment is used as the basis of overhauling, so that maintenance load and overhauling cost are reduced, and economy of the power plant is improved.
Description
Technical field:
The present invention relates to the accurate online strain monitoring field of High Temperature High Pressure metal parts, relate in particular to a kind of correlation technique of utilizing white light speckle, the device and method of the strain of noncontact, accurate on-line monitoring power plant high-temperature component.
Background technology:
The phenomenon of slowly plastic yield under constant temperature and constant effect of stress, occurs in metal material for a long time, is called creep.For common metal, creep only just obviously shows under hot conditions.The generation of creep is that the factor by three aspects consists of: temperature, stress and time.Carbon steel creep can occur significantly under the effect of stress in the time of 300～400 ℃.When temperature when being higher than 400 ℃, even stress is little, the creep of larger speed also will appear.When the temperature of alloy steel surpassed 400～450 ℃, under certain effect of stress, it is higher that creep, temperature will occur, and creep more obviously.
Power plant's high-temperature metal parts are at high temperature operation for a long time, and the high-temperature creep injury of material is inevitable problem, and the creep impairment of metal parts accumulates gradually, causes the high-temperature metal parts not move infinite life.Fig. 2 is the creep curve of a typical metal.Creep curve is divided into three phases.The creep rate of phase one reduces gradually, and the time of this one-phase is shorter; The creep rate of subordinate phase is constant, and metal parts substantially all runs on this one-phase; The creep rate of phase III increases gradually, is in the tertiary creep stage, will cause component failure in a short period of time.
The parts that produce creep in the High Temperature High Pressure thermal power plant are more,, high temperature securing member logical such as main steam line, boiler header, carbonated drink pipe, steam turbine etc.Because the accumulation of metal creep, make metal parts that excessive plastic yield occur and can not use, perhaps creep has entered into the accelerated development stage, and creep rupture occurs, and component failure is damaged, even major accident occurs.So, for the high-temperature component of long-time running, carry out strict creep monitoring.Certainly, some parts occur at work that some plastic yield still allow, as long as their within the whole working life (for example 100,000 hours) get final product because the amount of plastic deformation that creep is accumulated is no more than permissible value.For example, after general provision main steam line, the operation in 100,000 hours of high-temperature steam header, total deformation is no more than 1%; The total deformation of steam turbine after 100,000 hours is no more than 0.1%; Alloy steel superheater tube and the reheating pipe of boiler, swollen thick in 2.5% the time when creep, need to change; Carbon steel superheater tube and the reheater tube of boiler, swollen thick in 3.5% the time when creep, change at once.
In order to carry out exactly predicting residual useful life, must adopt the actual performance of material as the foundation of judging, otherwise bring unsafe hidden danger.When usually carrying out predicting residual useful life, in the situation that can't determine the material actual performance, often according to the standard value of material or the data of list of references, extrapolate the minimum of material property and estimate.So also the estimation of too guarding may be caused and the potentiality of equipment can not be given full play to.For example to make of the creep strength of material the life appraisal of structure, usually the standard value of the creep strength of material be reduced by 20% as its minimum.If but the testimonial material actual strength does not reduce by 20% on evidence, its prediction creep life just can double.Carry out life appraisal if use the measured value of creep strain accumulation instead, just avoided too conservative assessment result.
Present domestic power plant creep strain monitoring means mainly is the variation of measuring caliber and thickness, but the accuracy requirement that the variation of measuring caliber and thickness does not reach strain monitoring, so DL/T438-2009 " fuel-burning power plant alloying technology supervision rules " has cancelled the mandatory provisions of high-temperature pipe being installed creep measurement points.
Overseas power plants adopts high temperature strain foil or capacitive transducer etc. to measure creep.High temperature strain foil then is subject to the stability of high-temp glue and the impact of foil gauge and measured material temperature compensation, and measurement result is with many uncertainties.Capacitive transducer Installation and Measurement at the scene also has the place of many inconvenience, such as needs one signal line.These two kinds of methods are installed a measuring point and can only be measured a strain value.
Monitor strain also has a kind of method of non-contacting optics.Measuring displacement and strain with the method for optics has based on the interferometric method of light phase difference analysis with based on the non-interferometric method of light intensity analysis.What belong to the former has speckle interferometry and a moiréinterferometry, and what belong to the latter has speckle image method and a moire method.Laser is a kind of interference light, and laser hologram and laser speckle technique are measured displacement and strain has very high precision, and precision can reach the order of magnitude (a few tenths of micron) of optical maser wavelength.But the light source that laser uses must be the LASER Light Source of height correlation, and small vibration all can cause the distortion of record, is difficult to use at engineering site.White light speckle uses common white light source, has the function almost identical with laser speckle, is suitable for using at engineering site.
The patent of invention content:
The present invention is directed to above-mentioned problems of the prior art, a kind of correlation technique of utilizing white light speckle is provided, the device and method of the strain of noncontact, accurate on-line monitoring power plant high-temperature component.
The present invention is achieved by the following technical solutions:
Device based on the high-temperature pipe strain of white light speckle commercial measurement power plant, comprise positioning pedestal, strain transducer, focus apart from camera, positioning pedestal is welded on the pipeline, strain transducer places the positioning pedestal center, be welded on equally on the pipeline, focus apart from camera and be fixed on the strain transducer dead ahead, the alignment lens strain transducer is taken pictures.
Described strain transducer is that platinized platinum is made.
Described strain transducer is to be welded on the pipeline by the spot welding mode.
It is described that to focus apart from camera be focusing apart from camera with telecentric lens.
Described focusing apart from camera is fixed on the positioning pedestal by register pin.
Method based on the high-temperature pipe strain of white light speckle commercial measurement power plant may further comprise the steps:
(1) utilization focuses apart from camera the strain transducer before being out of shape is taken pictures;
(2) utilization focuses apart from camera the strain transducer after being out of shape is taken pictures;
(3) utilize computing machine the speckle image before and after the distortion to be processed the strain field that obtains whole zone;
(4) according to strain numerical value, judge whether the High Temperature High Pressure parts are in the tertiary creep stage and cause component failure.
Described step Computer disposal route is being out of shape two doublings of the image in front and back on identical position by computing machine, automatically carry out the correlation analysis of speckle, its essence is exactly to follow the tracks of each how much speckle point before distortion and the displacement vector after the distortion, thereby can obtain the displacement field in whole zone, after displacement field is determined, just can be in the hope of Strain Distribution.
Advantage of the present invention and beneficial effect are:
Creep impairment situation when (1) can monitor power plant high-temperature metal parts at high temperature moving has for a long time been avoided damaging the industrial accident that causes because high-temerature creep causes component failure.
(2) purpose of monitoring power plant high-temperature metal parts creep strain is for to assessing equipment life, carries out life appraisal with the measured value of creep strain accumulation, has just avoided too conservative assessment result, extension device serviceable life.
(3) power plant can be according to the time of the as a result decision device overhaul of creep strain, for example changes the interval of overhaul into 4 years from the past 2 years, namely with the foundation of equipment state as maintenance, reduces maintenance load and recondition expense, improves economy of power plant.
Description of drawings:
Fig. 1 is the device synoptic diagram that the present invention measures power plant's high-temperature pipe strain;
Fig. 2 is the creep curve figure of typical metal;
Fig. 3 is the principle schematic of speckle correlation technique;
Fig. 4 is that main steam line is along directions X average displacement curve;
Fig. 5 is that main steam line is along directions X mean strain curve.
Among the figure: 1, power plant's pipeline; 2, positioning pedestal; 3, strain transducer; 4, focus apart from camera.
Embodiment:
Embodiment 1:
Measure the strain of mother metal and weld seam at the main steam line of a certain power plant.The material of main steam line is 12Cr1MoV, and temperature is 540 ℃, and pressure is 16MPa.
1, utilize the thick platinized platinum sensor 3 of 0.1mm spot welder to adopt the mode of spot welding to be welded on the pipeline 1;
2, positioning pedestal 2 has rectangular through holes for the circular metal center, positioning pedestal 2 same points is welded on the pipeline 1, and makes rectangular through holes aligning platinized platinum sensor 3 centers, center that platinized platinum sensor 3 is exposed;
3, respectively there is a rhombus aperture at positioning pedestal 2 horizontal axis two ends, will be fixed on positioning pedestal (2) the rhombus aperture by register pin with focusing apart from camera (4) of telecentric lens;
4, utilization is taken pictures with focusing apart from the platinized platinum sensor 3 of 4 pairs of distortion front and back of camera of register pin;
5, utilize computing machine the speckle image before and after the distortion to be processed the strain field that obtains whole zone.
Can see the unevenness of weld seam strain from Fig. 4 and Fig. 5, the strain of weld heat-affected zone is far longer than the strain of mother metal.
Central principle of the present invention is:
When a branch of directional light shine one coarse when surperficial, its reflection is inhomogeneous, because some bright and dark spot, namely speckles will appear in the irregular reflection of light on image.This image of recording is the optical finger print on this coarse surface namely.Carry out twice photograph before distortion and after the distortion, because body structure surface deforms, change has also just occured in the figure of speckle, as shown in Figure 3.These two speckle images are carried out correlation analysis, just can obtain the Two dimensional Distribution of displacement and strain.
Adopt digital camera to take and just directly obtained digital image.After two pictures are input to computing machine, computer software just the doubling of the image on identical position, automatically carry out the correlation analysis of speckle.The principle of speckle correlation technique is exactly to follow the tracks of each geometric point before distortion and the displacement vector after the distortion.In fact, this can by follow the tracks of each speckle point before distortion and the distortion after displacement vector realize.Because two images all comprise same speckle point, and these speckle points just can be considered the fingerprint on test specimen surface, the speckle image on the test specimen surface before and after the distortion is recorded into two digital images, is designated as respectively reference picture I
1(r) and present image I
2(r), their pass is
I
2(
r)=?I
1[
r-
U(
r)]
I
1(
r)=?I
2[
r+
U(
r)]
Here
U(
R)It is pixel
rThe displacement vector of=(x, y).Around the pixel of reference picture, draw a subdomain, and calculate the difference of two subdomains according to predefined related function from the different pixel of present image.These three related functions commonly used are
Absolute difference
Least square
Crosscorrelation
Here (M * N) is around pixel to Ω
rThe area of subdomain.In fact, the related function of absolute difference and least square needs less calculating, and the cross correlation function of standard then needs relatively large calculating.Based on these related functions, in current image, find out certain phase vegetarian refreshments, this point can make two subdomains reach best coupling, namely makes related function obtain maximal value, and this phase vegetarian refreshments just is designated as O
'The phase vegetarian refreshments O of present image
'With the alternate position spike of the phase vegetarian refreshments O of reference picture, it is exactly the displacement vector of the phase vegetarian refreshments O of reference picture
U(
R)The displacement field that just can obtain whole zone is processed on computer programming system ground to image.After displacement field is determined, just can be in the hope of Strain Distribution.
The speckle image correlation technology is applied to the speckle image that needs to obtain can be used in strain analysis in the industry spot.The speckle characteristics of measured metallic surface can not change because of oxidation corrosion, and the practical approach that solves one of metal surface oxidation at high temperature is the metal at the metal surface of easily oxidation welding one deck high temperature oxidation resisting.Ferrous alloy can generate oxide skin under 500～600 ℃ of high temperature, directly destroy the speckle of metal surface; Nickel-base alloy is meeting variable color burnt hair under 500～600 ℃ of high temperature, affects the identification of speckle characteristics; The ductility of platinum is good, good in oxidation resistance, and color does not change under the high temperature, therefore is very suitable for being welded on base metal surface, the high-temp strain of reflection parent metal.
With spot welder platinized platinum is welded to above the parent metal.Spot welding is that weldment is soldered at indivedual points of joint surface of contact.Spot welding is owing to have certain spacing between solder joint, so only be used for not having the welding of the structural member of sealing requirements.Columnar electrode presses weldment and rotates, and cooperates pulsed energization, just can form one by one continuous and overlapping solder joint, forms weld seam, Here it is seam weldering or roll welding.It is mainly used in the welding of the thin plate that seal request or strength of joint have relatively high expectations.The mode that adopts the seam weldering is welded on parent metal to platinized platinum, does not have the space between the faying face of platinized platinum and parent metal, thus faying face not can and contact with air, the situation that platinized platinum comes off from parent metal can not occur certainly yet, the reliability of welding is very high.
Spot-wedling electrode is the strength member that guarantees point quality, and its major function has: (1) is to beam current through work-piece; (2) to the workpiece transmission of pressure; (3) conduct rapidly, distribute the heat of weld zone.
Therefore the heat-affected zone that the mode of spot welding forms is minimum, can not damage parent metal, does not also need parent metal such as is heat-treated at the measure after being soldered platinized platinum.
Image acquisition: preferred employing focuses apart from camera and adds telecentric lens.Common lens is used for the meeting of measurement and produces error, and it is main source of error that parallax and focusing are forbidden.The object space telecentric lens can eliminate object space because the inaccurate reading error of bringing of focusing.The two telecentric lens of image have the large depth of field, and in field depth the constant characteristics of image multiplying power.The means of illumination of telecentric lens adopts coaxial-illuminating.
Claims (7)
1. based on the device of white light speckle commercial measurement power plant high-temperature pipe strain, it is characterized in that device comprises positioning pedestal (2), strain transducer (3), focuses apart from camera (4), positioning pedestal (2) is welded on the pipeline (1), strain transducer (3) places positioning pedestal (2) center, be welded on equally on the pipeline (1), focus apart from camera (4) and be fixed on strain transducer (3) dead ahead, alignment lens strain transducer (3) is taken pictures.
2. described device based on the high-temperature pipe strain of white light speckle commercial measurement power plant according to claim 1 is characterized in that described strain transducer (3) makes for platinized platinum.
3. described device based on the high-temperature pipe strain of white light speckle commercial measurement power plant according to claim 1 is characterized in that described strain transducer (3) is to be welded on the pipeline (1) by the spot welding mode.
4. described device based on the high-temperature pipe strain of white light speckle commercial measurement power plant according to claim 1 is characterized in that described focusing apart from camera (4) is focusing apart from camera with telecentric lens.
5. described device based on the high-temperature pipe strain of white light speckle commercial measurement power plant according to claim 1 is characterized in that described focusing apart from camera (4) is fixed on the positioning pedestal (2) by register pin.
6. based on the method for white light speckle commercial measurement power plant high-temperature pipe strain, it is characterized in that may further comprise the steps:
(1) utilization focuses apart from camera the strain transducer (3) before being out of shape is taken pictures;
(2) utilization focuses apart from camera the strain transducer (3) after being out of shape is taken pictures;
(3) utilize computing machine the speckle image before and after the distortion to be processed the strain field that obtains whole zone;
(4) according to strain numerical value, judge whether the High Temperature High Pressure parts are in the tertiary creep stage and cause component failure.
7. described method based on the high-temperature pipe strain of white light speckle commercial measurement power plant according to claim 6, it is characterized in that described step (3) Computer disposal route is being out of shape two doublings of the image in front and back on identical position by computing machine, automatically carry out the correlation analysis of speckle, its essence is exactly to follow the tracks of each how much speckle point before distortion and the displacement vector after the distortion, thereby can obtain the displacement field in whole zone, after displacement field is determined, just can be in the hope of Strain Distribution.
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104613888A (en) * | 2015-02-03 | 2015-05-13 | 清华大学 | Method for measuring deformation of object in smoke under flame smoke environment |
| CN104792270A (en) * | 2015-04-16 | 2015-07-22 | 石家庄铁路职业技术学院 | Deep foundation pit detection method based on white-light digital image frequency domain analysis method |
| CN104990498A (en) * | 2015-06-16 | 2015-10-21 | 广东电网有限责任公司电力科学研究院 | Power plant boiler high-temperature pipe system macro displacement measurement device and method based on CCD photography |
| CN106500612A (en) * | 2016-10-12 | 2017-03-15 | 北京科技大学 | The non-contact measurement system of material members high temperature deformation and method |
| CN110736671A (en) * | 2018-07-19 | 2020-01-31 | 大唐南京发电厂 | method for monitoring abnormal part of pipe fitting hardness |
| CN113607041A (en) * | 2021-07-07 | 2021-11-05 | 华能(浙江)能源开发有限公司玉环分公司 | Online creep monitoring method for pipeline weld joint of ultra-supercritical coal-fired generator |
| CN113984495A (en) * | 2021-10-15 | 2022-01-28 | 中国航发北京航空材料研究院 | High-temperature non-contact deformation measurement precision verification method |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201096733Y (en) * | 2007-04-19 | 2008-08-06 | 华东理工大学 | A measuring device for coated layer high-temperature worm distortion |
| JP2008232686A (en) * | 2007-03-19 | 2008-10-02 | Saitama Prefecture | Deformation measuring device, deformation measuring method, and deformation measuring program |
| JP2010249589A (en) * | 2009-04-14 | 2010-11-04 | Toyo Seiki Seisakusho:Kk | Method and device for measuring strain |
| CN203337109U (en) * | 2013-07-15 | 2013-12-11 | 国家电网公司 | Device for measuring strains of power plant high-temperature pipelines based on white-light speckle technology |
-
2013
- 2013-07-15 CN CN2013102941664A patent/CN103363919A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008232686A (en) * | 2007-03-19 | 2008-10-02 | Saitama Prefecture | Deformation measuring device, deformation measuring method, and deformation measuring program |
| CN201096733Y (en) * | 2007-04-19 | 2008-08-06 | 华东理工大学 | A measuring device for coated layer high-temperature worm distortion |
| JP2010249589A (en) * | 2009-04-14 | 2010-11-04 | Toyo Seiki Seisakusho:Kk | Method and device for measuring strain |
| CN203337109U (en) * | 2013-07-15 | 2013-12-11 | 国家电网公司 | Device for measuring strains of power plant high-temperature pipelines based on white-light speckle technology |
Non-Patent Citations (1)
| Title |
|---|
| 陈志新等: "数字散斑相关法在变形测量中的应用", 《光学精密工程》 * |
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| CN104613888A (en) * | 2015-02-03 | 2015-05-13 | 清华大学 | Method for measuring deformation of object in smoke under flame smoke environment |
| CN104613888B (en) * | 2015-02-03 | 2017-06-13 | 清华大学 | Smog deformation of body measuring method is passed through under a kind of flame smoky environment |
| CN104792270A (en) * | 2015-04-16 | 2015-07-22 | 石家庄铁路职业技术学院 | Deep foundation pit detection method based on white-light digital image frequency domain analysis method |
| CN104990498A (en) * | 2015-06-16 | 2015-10-21 | 广东电网有限责任公司电力科学研究院 | Power plant boiler high-temperature pipe system macro displacement measurement device and method based on CCD photography |
| CN104990498B (en) * | 2015-06-16 | 2017-07-18 | 广东电网有限责任公司电力科学研究院 | Based on the CCD macroscopical displacement measuring devices of station boiler high temperature piping photographed and method |
| CN106500612A (en) * | 2016-10-12 | 2017-03-15 | 北京科技大学 | The non-contact measurement system of material members high temperature deformation and method |
| CN106500612B (en) * | 2016-10-12 | 2019-08-06 | 北京科技大学 | The non-contact measurement system and method for material members high temperature deformation |
| CN110736671A (en) * | 2018-07-19 | 2020-01-31 | 大唐南京发电厂 | method for monitoring abnormal part of pipe fitting hardness |
| CN110736671B (en) * | 2018-07-19 | 2022-07-22 | 大唐南京发电厂 | Method for monitoring abnormal part of pipe fitting hardness |
| CN113607041A (en) * | 2021-07-07 | 2021-11-05 | 华能(浙江)能源开发有限公司玉环分公司 | Online creep monitoring method for pipeline weld joint of ultra-supercritical coal-fired generator |
| CN113984495A (en) * | 2021-10-15 | 2022-01-28 | 中国航发北京航空材料研究院 | High-temperature non-contact deformation measurement precision verification method |
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