Summary of the invention
The object of the invention is, for the deficiencies in the prior art, improve, propose a kind of reliable and effective method assessment corrugated tube metaboly.
For achieving the above object, the technical solution used in the present invention is: a kind of novel corrugated tube vibration-testing and Deformation Reasons appraisal procedure, it is characterized in that, adopt following methods to realize:
(1) adopt New corrugated pipe method for testing vibration, obtain the vibration signal of the current running status of corrugated tube;
In corrugated tube vibration-testing, at corrugated tube radially same shaft section orthogonal active position place and axial positions arrange vibration transducer, obtain the vibration signal of reflection corrugated tube current actual motion state; This vibration signal is obtained by X, Y, tri-direction sensor collections of Z, and all previous test shows corrugated tube stress concentration portion position, and its vibration performance is larger; So choose the concentrated position of corrugated tube stress as test position, that is: corrugated tube near in the middle of oil pump side, corrugated tube, corrugated tube is near base side, strengthen measuring point and choose refrigeratory oil pump, refrigeratory blower fan as test position;
(2) carry out spectrum analysis by the vibration signal that above-mentioned measuring point is obtained, obtain corrugated tube vibration and deformation analysis; Vibration analysis shows: vibrating larger its vibration source of corrugated tube is that refrigeratory oil pump and refrigeratory blower fan cause, from oil pump side corrugated tube to base side corrugated tube, vibration is weak gradually.
The invention has the beneficial effects as follows: novel corrugated tube vibration-testing provided by the invention and Deformation Reasons appraisal procedure, comprise New corrugated pipe method for testing vibration, and proposed a kind of corrugated tube Deformation Reasons appraisal procedure; During this patent is implemented, 77 groups of corrugated tubes to 18 of 11 transformer stations transformers and 36 groups of corrugated tubes of 12 reactors have carried out vibration-testing, assess the corrugated tube that has metaboly, search out corrugated tube Deformation Reasons and carried out technological transformation, vibration-testing shows that changing rear ripple tube vibration reduces, successful.
Embodiment
In order to understand better the present invention, further illustrate content of the present invention below in conjunction with embodiment, but content of the present invention is not only confined to the following examples.Those skilled in the art can make various changes or modifications the present invention, and these equivalent form of values are equally within the listed claims limited range of the application.
This method adopts the method that corrugated tube vibration characteristics, stress analysis are combined to carry out Deformation Reasons assessment to corrugated tube first.
In analysis, select stress analysis method to analyze corrugated tube stressing conditions, determined corrugated tube vibration measuring point; There is resonance relation in the vibration characteristics of its vibration characteristics of corrugated tube and body, oil pump and fan, therefore on basic measuring point basis, has added reinforcement measuring point, determines thus final measuring point scheme; In corrugated tube vibration-testing, at corrugated tube radially same shaft section orthogonal active position place and axial positions arrange vibration transducer, obtain the vibration signal of the current actual motion state of reflection corrugated tube, this signal is obtained by X, Y, tri-direction sensor collections of Z, by this characteristic signal is carried out to spectrum analysis, obtain the health status at each position of corrugated tube; Corrugated tube vibration-testing and Deformation Reasons assessment technology route are as Fig. 1.
1, New corrugated pipe method for testing vibration
In corrugated tube vibration-testing, at corrugated tube radially same shaft section orthogonal active position place and axial positions arrange vibration transducer, obtain the vibration signal of reflection corrugated tube current actual motion state.This signal is obtained by X, Y, tri-direction sensor collections of Z, by this characteristic signal is carried out to spectrum analysis, obtains the health status at each position of corrugated tube; All previous test shows corrugated tube stress concentration portion position, and its vibration performance is larger; So choose the concentrated position of corrugated tube stress as test position, measuring point is arranged as shown in Fig. 1 and following table 1.
Table 1 measuring point method for arranging
2, corrugated tube deformation intensity appraisal procedure
Corrugated tube is the link that refrigeratory and body are flexible coupling, under the effect of forced circulation oil pump, alterante stress when it is subject to oil pump and fan running for a long time, the stress at its stress characteristics and main-transformer binding site, oil pump and fan combination position is closely related; In the time that corrugated tube cannot bear the stress of oil pressure generation, stress concentration portion position is prone to as the defect such as crimp, dislocation, causes corrugated tube to produce fatigue crack.In this method, select spectrum signature and stress distribution to assess corrugated tube deformation intensity.
77 groups of corrugated tubes of 18 transformers and 36 groups of corrugated tubes of 12 reactors for 11 transformer stations have carried out vibration-testing, have chosen four larger corrugated tubes of vibration and have carried out deformation intensity assessment, as table 2.
Table 2 corrugated tube larger vibration value distributes and frequency spectrum
(1), corrugated tube stress characteristics is analyzed
Normal corrugated tube is in service, and radial stress, axial stress, circumferential stress act on outside surface table, are evenly distributed along pipe range; The outside surface of corrugated tube, axial stress is the most remarkable, all shows as tension along whole tube wall; The axial stress at trough place is larger than the axial stress in the same terms lower straighttube, crest place contrary.Corrugated tube stress distribution is as Fig. 3.
Wherein: radial stress refers to that corrugated tube outside surface is under radial drawing load, the suffered stress of tube wall; Axial stress spindle is under tensile load effect, and tube wall is suffered stress outward; Circumferential stress refers to that corrugated tube outside surface is under the effect of hoop tensile load, the suffered stress of tube wall.
In installing, there is axis die misalignment in corrugated tube, cause corrugated tube axis to have broken line, corrugated tube in service is because compensation need to will produce axial stress, radial stress, circumferential stress, wherein axial stress, circumferential stress are larger, under its effect, can cause that corrugated tube produces dilatation, causes plastic yield phenomenon.Corrugated tube metaboly and force analysis are as Fig. 4.
When corrugated tube is installed, basis installed height mark is too high, produce larger circumferential stress and radial stress, form larger moment of torsion, make corrugated tube bear huge distortion, now the axial stress at corrugated tube crest place continues larger, under axial torsional interaction, the plastic yield phenomenon of close Zhou Biankuan in the middle of corrugated tube presents.Corrugated tube metaboly, stress analysis, torsional deformation are as Fig. 5.
When corrugated tube is installed, the flange faying face depth of parallelism is inadequate, make the maximum tension length that supports expansion joint exceed claimed range, when on-the-spot installation, suffer restraints for the mechanical boundary conditions of adjusting installation length, corrugated tube entirety bending resistance is died down, larger axial stress acts on whole corrugated tube profile, makes the larger formation plastic yield of local deformation amount, produces pitch of waves uneven phenomenon.Corrugated tube metaboly, stress analysis are as Fig. 6.
(2), corrugated tube spectrum sigtral response
77 groups of corrugated tubes of 18 transformers and 36 groups of corrugated tubes of 12 reactors for 11 transformer stations have carried out vibration-testing, have chosen four larger corrugated tubes of vibration and have carried out vibration performance analysis, and as table 3, spectrum signature is shown in Fig. 7~10.
Table 3 corrugated tube larger vibration value distributes and frequency spectrum
Vibration analysis shows: vibrating larger its vibration source of corrugated tube is that oil pump and blower fan cause, weak gradually to main transformer body side wave line tube vibration from oil pump side corrugated tube.
3, novel corrugated tube method for testing vibration case verification
The big desert 330kV 1# of transformer station main-transformer 4# refrigeratory corrugated tube Horizontal Vibration value is 200 μ m, and frequency is 15Hz; Observe after testing and find that corrugated tube and oil-immersed pump flange connection surface be not at same center line, corrugated tube produces distortion, due to refrigeratory, be combined the insecure refrigeratory Horizontal Vibration that causes with fixed support larger, directly vibration reached to corrugated tube long-time running and cause corrugated tube vibration that fatigue breakdown occurs.Because corrugated tube distortion is increase tendency, corrugated tube mounting means is carried out to technological transformation; Before the transformation of 1# main-transformer 4# refrigeratory Bellows Technology, ripple tube vibration value is as table 4.
(μ m) in the front 1# main transformer 4# refrigeratory corrugated tube vibration detection of table 4 technological transformation value unit
Measuring point
|
1
|
2
|
3
|
4
|
5
|
6
|
7
|
Vibration values
|
38 |
130 |
33 |
200 |
86 |
37 |
16 |
By the analysis to the vibration of corrugated tube place and deformation, corrugated tube vibrates greatly and corrugated tube distortion is aggravation trend; Contrast corrugated tube metaboly and spectrum signature, it is identical with sample 1 and sample 4 types, and stress distribution situation is similar; So corrugated tube mounting means has been carried out to technological transformation in conjunction with the original design data of corrugated tube, corrugated tube and oil-immersed pump faying face center line carry out centering, and fan and bracing frame faying face are installed additional to pad make it in conjunction with firmly tight.After technological transformation, 1# main transformer 4# refrigeratory corrugated tube vibration detection value is as table 5.
After table 5 technological transformation 1# main transformer 4# refrigeratory corrugated tube vibration detection value unit (μ m)
Measuring point
|
1
|
2
|
3
|
4
|
5
|
6
|
7
|
Vibration values
|
19 |
87 |
23 |
97 |
80 |
45 |
9 |
The foregoing is only the preferred embodiments of the present invention, be not limited to the present invention.The content not being described in detail in this instructions belongs to the known prior art of professional and technical personnel in the field.