CN104564182A - Processing method for steam turbine generator unit of nuclear power station - Google Patents
Processing method for steam turbine generator unit of nuclear power station Download PDFInfo
- Publication number
- CN104564182A CN104564182A CN201310746887.4A CN201310746887A CN104564182A CN 104564182 A CN104564182 A CN 104564182A CN 201310746887 A CN201310746887 A CN 201310746887A CN 104564182 A CN104564182 A CN 104564182A
- Authority
- CN
- China
- Prior art keywords
- generator
- sensor stand
- nuclear power
- power station
- vibration
- 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.)
- Granted
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
Abstract
The invention relates to the technical field of power generators in nuclear power stations and provides a processing method for a steam turbine generator unit of a nuclear power station. According to the processing method, the situation that vibration is caused by the abnormity of a pickup vibration link caused by resonance of a sensor bracket is analyzed by comparing the situation of an abnormal upper bearing bushing at the rear end of a power generator and that of a normal bearing bushing at the front end of the power generator, the resonance is avoided by calculating the inherent frequency of the sensor bracket and changing the inherent frequency, and thus the vibration of the bearing bushings is eliminated. By adoption of the method, the vibration of the bearing bushings can be accurately and rapidly found out, the detection on the generator unit by opening a cylinder is not needed, the time is saved and the maintenance cost is greatly reduced.
Description
Technical field
The present invention relates to the technical field of generators in nuclear power station, more particularly, relate to the disposal route of nuclear power station Turbo-generator Set.
Background technology
The principle of work of Class PWR Plants is: pressure coolant is sent into reactor by main pump, cooling medium takes reactor out of the heat energy that nuclear fuel is released, and enters steam generator, by thousands of heat-transfer pipes, heat is passed to the secondary circuit water outside pipe, water is seethed with excitement and produces steam.After cooling medium flows through steam generator, then send into reactor by main pump, circulate so back and forth, constantly the heat in reactor taken out of and change generation steam.From steam generator high temperature and high pressure steam out, promote Turbo-generator Set generating.
As shown in Figure 1, be the shaft system arrangement schematic diagram of secondary circuit Turbo-generator Set, it comprises high intermediate pressure cylinder 11, first low pressure (LP) cylinder 12, second low pressure (LP) cylinder 13 and generator 14 that connect successively.Wherein, high intermediate pressure cylinder 11 comprises front end 1 and rear end 2, first low pressure (LP) cylinder 12 comprises front end 3 and rear end 4, second low pressure (LP) cylinder 13 comprises front end 5 and rear end 6, and generator 14 comprises front end 7 and rear end 8.The rear end 2 of high intermediate pressure cylinder 11 is connected with the front end 3 of the first low pressure (LP) cylinder 12, and the rear end 4 of the first low pressure (LP) cylinder 12 is connected with the front end 5 of the second low pressure (LP) cylinder 13, and the rear end 6 of the second low pressure (LP) cylinder 13 is connected with the front end 7 of generator 14.Under Operation at full power state, the saturated vapour that steam generator produces first is delivered to steam turbine high pressure steam chest by main steam line, to regulate the quantity of steam entering high pressure cylinder, enters expansion work high intermediate pressure cylinder 11 from high pressure steam chest steam out by annular steam pipeline.A steam discharge part for high intermediate pressure cylinder 11 is sent to oxygen-eliminating device, major part carries out carbonated drink separation by row of conduits in two separators being positioned at low pressure (LP) cylinder both sides, sends into continuation expansion work in the first low pressure (LP) cylinder 12 and the second low pressure (LP) cylinder 13 from separator superheated vapor out respectively through pipeline.In expansion work process, the rotor of drive electrical generators 14 rotates in the stator, does the motion of cutting magnetic line, thus produces induced potential, is drawn, connect in the loop, just create electric current by connection terminal.
During Self-debugging since red switch first, all there are online 8 watts (i.e. the bearing shell at generator 14 rear end 8 place, referred to as 8 watts) and vibrate higher in two units, and the situation of fluctuation.After business's fortune during Operation at full power, 8 watts of on-line vibration sensors are at KIC(Plant Computer Information & Control, power station computerized information and control system) on displayed value obviously bigger than normal, its watt shakes once more than ISO(International Standardization Organization, ISO (International Standards Organization)) international standard, axle shakes and also surpasses producer's control criterion limit value once in a while.
For the problems referred to above, staff is by hydrogen temperature, SRI(Conventional Island Closed Cooling Water, the closed circuit cooling water system of conventional island) checking of the series of experiments such as water temperature, the adjustment of exciter wind-warm syndrome, and in conjunction with the vibration trend comparison of in-site measurement outer end cap vibration with inner end cap probe place online, and the correlation analysis of two place's signals when there is disturbance, judge that online probe place abnormal vibration situation is spurious signal.This shows that the signal that on-line sensor delivers to KIC by board is unreliable, can not reflect the indeed vibrations level of generator bearing shell really, and such master control operations staff loses supervision to generator important parameter, serious threat unit safety.Equally, owing to the indeed vibrations situation of bearing shell not detected, also effective removing measure cannot be taked to vibration.
Summary of the invention
Technical matters to be solved by this invention is the defect overcoming prior art, a kind of disposal route of steam turbine for nuclear power station group is provided, adopts and eliminate bearing shell vibration quickly in this way, save servicing time, reduce maintenance cost, make on-line sensor obtain reliable signal and be sent to KIC.
For solving the problems of the technologies described above, technical scheme of the present invention is: the disposal route providing a kind of nuclear power station Turbo-generator Set, comprises the following steps:
S1: the axle of rear end vertical direction gathering generator shakes and watt to shake, carrying out the spectrogram that spectrum analysis obtains the rear end vertical direction of generator, to shake power frequency component b by finding out the shake fundamental component frequency a of value and the Distribution value that watt to shake, axle of axle within the scope of 10 ~ 1000Hz in spectrogram
1and the component c at fundamental component frequency a place
1;
The axle of rear end horizontal direction gathering generator shakes and watt to shake, and carries out the spectrogram that spectrum analysis obtains the rear end horizontal direction of generator, to shake power frequency component b by finding out axle in spectrogram
2and the component c at fundamental component frequency a place
2;
The axle of front end vertical direction gathering generator shakes and watt to shake, and carries out the spectrogram that spectrum analysis obtains the front end vertical direction of generator, by the component c found out in spectrogram at fundamental component frequency a
3;
The axle of front end horizontal direction gathering generator shakes and watt to shake, and carries out the spectrogram that spectrum analysis obtains the front end horizontal direction of generator, by the component c found out in spectrogram at fundamental component frequency a
4;
S2: compare b respectively
1with b
2, c
1with c
2, c
3, c
4whether close; If b
1with b
2close, c
1with c
2, c
3, c
4keep off, judge that the vibration of the rear end vertical direction of generator comes from pick-up link abnormal, continue following step S3; If b
1with b
2keep off, c
1with c
2, c
3, c
4close, judge that the vibration of the rear end vertical direction of generator comes from rotor unbalance or support stiffness is inadequate, then check rotor balancing or increase support stiffness;
S3: check whether on-line vibration sensor and/or cable cause pick-up link abnormal by electromagnetic interference (EMI), if so, arrange shield assembly to eliminate electromagnetic interference (EMI); If not, judge the abnormal resonance coming from sensor stand of pick-up link, adopt the natural frequency f of finite element method calculating sensor support;
S4: the natural frequency f changing sensor stand avoids resonance, eliminates pick-up link abnormal, thus eliminates bearing shell vibration.
The disposal route of a kind of nuclear power station Turbo-generator Set provided by the invention, by the generator rear end top bearing shell situation and normal front end bearing shell that occur exception are compared, analyze vibration come from sensor stand resonate cause pick-up link exception, change natural frequency to avoid resonance by the natural frequency of calculating sensor support, thus elimination bearing shell vibration, adopt in this way, accurately find fast and eliminate bearing shell vibration, do not need to open cylinder inspection to generator, save time, greatly reduce maintenance cost.
Accompanying drawing explanation
Fig. 1 is the shaft system arrangement schematic diagram of secondary circuit steamer half speed generator of the present invention;
Fig. 2 is the process flow figure of the nuclear power station Turbo-generator Set that the embodiment of the present invention provides;
Fig. 3 is the structural representation of the sensor stand that the embodiment of the present invention provides;
Fig. 4 is that generator 8V axle that the embodiment of the present invention provides shakes spectrogram;
Fig. 5 is that generator 8V watt that the embodiment of the present invention provides shakes spectrogram;
Fig. 6 is generator 8H, 7V, 7H on-line vibration spectrogram that the embodiment of the present invention provides;
Fig. 7 is the structure cut-away view of the electromagnetic interference shield that the embodiment of the present invention provides;
Fig. 8 is the electromagnetic interference shield principle schematic that the embodiment of the present invention provides;
Fig. 9 is the double shield structure schematic diagram that the embodiment of the present invention provides;
Figure 10 is the schematic diagram of the measurement parameter sequence upload and download that the embodiment of the present invention provides;
Figure 11 is the schematic diagram setting up image data sequence in Emonitor software that the embodiment of the present invention provides;
Figure 12 is that the speed pickup that provides of the embodiment of the present invention arranges schematic diagram in Emonitor software;
Figure 13 is Enpac2500 off-line measurement 8V watt of spectrum diagram of shaking that the embodiment of the present invention provides;
Figure 14 is that in the embodiment of the present invention, balancing weight is installed on the structural representation after sensor stand;
Figure 15 is the structural representation of balancing weight in the embodiment of the present invention.
Embodiment
In order to make object of the present invention, technical scheme and advantage clearly understand, below in conjunction with drawings and Examples, the present invention is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the present invention, be not intended to limit the present invention.
With reference to Fig. 2, embodiments provide a kind of disposal route of nuclear power station Turbo-generator Set, it is to eliminate pressurized-water reactor nuclear power plant Half Speed generator bearing shell vibration, therefore particularly, also be a kind of method eliminating pressurized-water reactor nuclear power plant Half Speed generator bearing shell vibration, the method comprises the following steps:
S1: the axle of rear end vertical direction gathering generator shakes and watt to shake, and carries out the spectrogram that spectrum analysis obtains the rear end vertical direction of generator.To shake power frequency component b by finding out the shake fundamental component frequency a of value and the Distribution value that watt to shake, axle of axle within the scope of 10 ~ 1000Hz in spectrogram
1and the component c at fundamental component frequency a place
1;
The axle of rear end horizontal direction gathering generator shakes and watt to shake, and carries out the spectrogram that spectrum analysis obtains the rear end horizontal direction of generator, to shake power frequency component b by finding out axle in spectrogram
2and the component c at fundamental component frequency a place
2;
The axle of front end vertical direction gathering generator shakes and watt to shake, and carries out the spectrogram that spectrum analysis obtains the front end vertical direction of generator, to shake power frequency component b by finding out axle in spectrogram
3and the component c at fundamental component frequency a place
3;
The axle of front end horizontal direction gathering generator shakes and watt to shake, and carries out the spectrogram that spectrum analysis obtains the front end horizontal direction of generator, to shake power frequency component b by finding out axle in spectrogram
4and the component c at fundamental component frequency a place
4;
S2: compare b respectively
1with b
2, c
1with c
2, c
3, c
4whether close; If b
1with b
2close, c
1with c
2, c
3, c
4keep off, judge that the vibration of the rear end vertical direction of generator comes from pick-up link abnormal, continue following step S3; If b
1with b
2keep off, c
1with c
2, c
3, c
4close, judge that the vibration of the rear end vertical direction of generator comes from rotor unbalance or support stiffness is inadequate, then check rotor balancing or increase support stiffness;
S3: check whether on-line vibration sensor and/or cable cause pick-up link abnormal by electromagnetic interference (EMI), if so, arrange shield assembly to eliminate electromagnetic interference (EMI); If not, judge the abnormal resonance coming from sensor stand of pick-up link, adopt the natural frequency f of finite element method calculating sensor support;
S4: the natural frequency f changing sensor stand avoids resonance, eliminates pick-up link abnormal, thus eliminates bearing shell vibration.
Composition graphs 1, in step sl, namely the rear end vertical direction of generator is 8 place's vertical direction in Fig. 1, herein referred to as 8V direction, in background technology, mention signals collecting is obtained by on-line vibration sensor, and on-line vibration sensor actual installation is on a sensor stand.With reference to Fig. 3, the structural representation of sensor stand 100 in the embodiment of the present invention, sensor stand 100 comprises that the back up pad 110, the level that vertically arrange are located at the contact plate 120 of side, back up pad top, level is located at back up pad opposite side, and watt to shake measuring mechanism 130 and the axle be located at below the measuring mechanism 130 that watt to shake shakes measuring mechanism 140.Wherein, contact plate 120 and half speed generator (half speed generator is relative generator at full speed, and the rotating speed referring to when Steam Turbine is normally run is the half of generator at full speed) are encouraged end bearing shell and are fixedly connected with, and form rigid structure.The measuring mechanism 130 that watt to shake encourages the situation of watt shaking of end bearing shell for indirectly measuring half speed generator, the axle measuring mechanism 140 that shakes is fixed on the bottom of back up pad 110, and the axle of encouraging end bearing shell for indirectly measuring half speed generator shakes situation.When contact plate 120 and half speed generator encourage hold bearing shell fixing after, whole sensor stand is equivalent to a free beam, a bit fixing, and one end is freely.Under state is carried out to sensor fixed support duty and generator, carry out analog simulation, comprise corresponding static and dynamic analysis and calculate, evaluate its performance.
It is actual in step S1 performs, the axle of the generator 8V collected by above-mentioned on-line vibration sensor is shaken and watt to shake, carry out spectrum analysis, obtain the rumble spectrum figure at generator 8V place, please refer to Fig. 4 and Fig. 5, as can be seen from the figure, axle value of shaking and watt to shake all to be presented within the scope of 10 ~ 1000Hz and mainly based on 100Hz frequency component, namely be above-mentioned fundamental component frequency a be 100Hz, and be about 70 μm at the component of 100Hz.In the present embodiment, to the rear end horizontal direction of generator and the information acquisition of 8H, simultaneously, due to the front end vertical direction of generator and the vibration of 7V and horizontal direction 7H normal, therefore also information acquisition is carried out to 7V and 7H, be used for contrasting with the 8V of exception, be convenient to search reason.Composition graphs 6, contrasting 8V and 8H/7V/7H at the bobbin spectrogram that shakes, shows that the axle of 8V and 8H shakes power frequency component b
1with b
2all at about 15 μm, and the axle of 7V/7H shakes, power frequency component is about 10 μm; 8V axle shakes a and 100Hz component c
1be about 70 μm, and a and the 100Hz component c that each axle of 8H, 7V and 7H shakes
2, c
3, c
4all be less than 5 μm.
Because known abnormal vibration itself appears at 8V place, therefore when carrying out data and comparing, usually only there are above-mentioned two kinds of comparative results, i.e. b
1with b
2close, c
1with c
2, c
3, c
4keep off, judge that the vibration of 8V comes from pick-up link abnormal, continue following step S3, or b
1with b
2keep off, c
1with c
2, c
3, c
4close, judge that the vibration of work 8V comes from rotor unbalance or support stiffness is inadequate, check rotor balancing or increase support stiffness.It should be noted that, " close " of carrying out here when data compare is by the conclusion in experience range, in light of the circumstances, specifically determines, so determine whether as close without concrete scope herein.Be front a kind of result according to Information Monitoring in the present embodiment, i.e. b
1with b
2close, c
1with c
2, c
3, c
4keep off, judge that the vibration of 8V comes from pick-up link abnormal, continue following step S3.
Particularly, in step s3, whether on-line vibration sensor and/or cable cause pick-up link abnormal by electromagnetic interference (EMI) to adopt signal shielding test to check.And signal shielding test comprises the following steps:
Sa: speed pickup is set on sensor stand 100, and electromagnetic interference shield is set on described speed pickup;
Sb: the parameter that the speed pickup doing described electromagnetic interference shield process is gathered, i.e. vibration values and frequency spectrum, the vibration values gathered with the described on-line vibration sensor not doing shielding processing and Frequency spectrum ratio pair, if comparison result is consistent, then whether eliminating on-line vibration sensor and/or cable cause pick-up link abnormal by electromagnetic interference (EMI), if comparison result is inconsistent, then illustrate that on-line vibration sensor and/or cable cause pick-up link abnormal, then carry out arranging shield assembly to eliminate the step of electromagnetic interference (EMI) to linearly coupled sensor and/or cable in S3.
With reference to Fig. 7, it is the electromagnetic interference shield 200 structure cut-away view that above-mentioned steps Sa uses.Electromagnetic interference shield 200 comprises the upper radome 210 of upper and lower docking and lower radome 220, described speed pickup is placed in space that upper radome 210 and lower radome 220 enclose, the extension line of described speed pickup is twisted-pair feeder, by upper radome 210 Base top contact.In the present embodiment, upper radome 210 and lower radome 220 are aluminum products.For guaranteeing effectiveness, on aluminum, radome 210 and lower radome 220 adopt two sections of DN40 aluminum pipes respectively, and become flange with the thick aluminium sheet welding production of 2mm, on aluminium sheet, surrounding opens 4 10mm bolts hole, by the set bolt 230 of aluminum, flange is fastening.Like this, upper radome 210 and lower radome 220 also constitute a conduction, closed radome jointly, and speed pickup is installed in radome, top drilling for drawing the twisted-pair feeder of speed pickup, twisted-pair feeder outer wrapping double shield layer.
In the present embodiment, set bolt 230 is with insulating sleeve 240, and this is to prevent due to Shielding Case grounding thus destroying the insulation of generator.Set bolt 230 and the support iron plate 250 being used for placing speed pickup are also isolated by insulating sleeve 240 simultaneously, thus avoid the electromagnetic interference (EMI) that support iron plate 250 is transmitted.Between upper radome 210 and support iron plate 250, insulation spacer 260 is respectively equipped with between support iron plate 250 and lower radome 220, insulation spacer 260 is epoxy resin or mica sheet, like this, avoid radome 210, lower radome 220 directly contacts with support iron plate 250, finally avoid the electromagnetic interference (EMI) that support iron plate 250 is transmitted.
In the present embodiment, support iron plate 250 is steel plate material, is specially Q235 carbon steel.The sleeve outer diameter 12mm of insulating sleeve 240, thickness 1.5 ~ 2mm.
It should be noted that, electromagnetic interference shield 200 needs ground connection, and its concrete earthing mode is by the screen layer of twisted-pair feeder as extension line, and one end is connected with electromagnetic interference shield 200, and the other end is at external ground.
Due to the conductor that aluminium is good; according to the principle of electrostatic screening; as shown in Figure 8; utilize the inductive effect that electromagnetic interference shield 200 is produced by outfield to resist the impact in outfield; thus set up barrier for " protected location "; inhibit extraneous interference, the magnetic field intensity making aluminum electromagnetic interference shield 200 inside is zero, eliminates the impact of alternating magnetic field on speed pickup.
As shown in Figure 9, double shield structure comprises: internal shield 270 and external shielding layer 280, and wherein, internal shield 270 is enclosed with twisted-pair feeder 290, and internal shield 270 is copper wires, and external shielding layer 280 is enclosed with internal shield, and external shielding layer 280 is steel wires.The extension line of speed pickup generally adopts traditional concentric cable, but the invention provides the twisted-pair feeder being provided with double shield structure, has good magnetic field shielding effect, also eliminates the impact in magnetic field in the link of speed pickup wire output signal.
By arranging shield assembly for speed pickup in the present embodiment, and propose the double shield structure of the extraction wire of speed pickup thus magnetic field shielding is carried out to extraction wire, substantially eliminating the impact of electromagnetic interference (EMI).
Result shows, and within the scope of the speed pickup vibration survey amplitude of setting up and 10 ~ 1000Hz thereof, frequency spectrum and 8V online watt of measurement result of shaking is consistent.Can judge that 100Hz component in 8V on-line measurement frequency spectrum and signal disturbing have nothing to do accordingly, thus to eliminate pick-up link be because of electromagnetic interference (EMI) extremely, if caused by electromagnetic interference (EMI), then need to arrange shield assembly to eliminate.
As preferred scheme, in the embodiment of the present invention, confirm as pick-up link abnormal after, also can adopt further before carrying out signal shielding test and off-line measurement is carried out to 8V, obtain axle within the scope of 10 ~ 1000Hz and to shake the fundamental component frequency d of value and the Distribution value that watt to shake, and whether compare d and a consistent, if d and a is consistent, then get rid of pick-up link abnormal, if d and a is inconsistent, then confirm that pick-up link is abnormal, then carry out above-mentioned signal shielding test.This off-line measurement supplementing as on-line system, can reflect the indeed vibrations state of unit more accurately, analyzes the basic reason that vibration is high.Certainly, also off-line measurement can not be carried out.
In the present embodiment, carry out off-line measurement, comprise the following steps:
One temporary sensory device is arranged at generator ' s cover first half convex edge vertically locate;
Measurement parameter sequence is set up in Emonitor software;
Described measurement parameter sequence is downloaded in data acquisition unit;
The data of temporary sensory device repeatedly off-line measurement are saved to described data acquisition unit, and are uploaded to Emonitor software database by data acquisition unit and carry out trend and spectrum analysis, obtain above-mentioned fundamental component frequency d.
In above-mentioned steps, data acquisition unit is the Enpac2500 data acquisition unit of Rockwell Corporation, itself and Emonitor software combine, and realize vibration analysis by image data sample, this be also domestic adopt first this combination come Measurement and analysis diagnosis vibration high problem.
Particularly, after Enpac2500 data acquisition unit and Emonitor combination of software, realize data acquisition and set up measurement parameter sequence, by measurement parameter sequence from Emonitor software download to Enpac2500 data acquisition unit, then the off-line vibration data of Enpac2500 data acquisition unit pick-up transducers measurement, described off-line vibration data specifically can comprise amplitude, process variable, frequency spectrum, time waveform and phase data etc., finally the off-line vibration data of collection is uploaded to Emonitor database from Enpac2500 and analyzes.As Figure 10, it is the schematic diagram of measurement parameter sequence upload and download.
Particularly, for understanding the indeed vibrations situation of 8V, be first that measurement parameter sequence is targetedly set up in the collection of 8V vibration data in Emonitor software; Wherein, in measurement parameter sequence, predefined is needed: measurement data option, arrange to measure and gather definition and setting measurement parameter etc.; Then the measurement parameter sequence will set up, is downloaded to Enpac2500 data acquisition unit.
With reference to Figure 11, for setting up image data sequence in Emonitor software.As a kind of concrete embodiment, described measurement data option comprises measures type, measurement wave filter, measuring unit; Described arrange measure gather definition comprise sensor type, measuring-signal type of detection, the scope of survey frequency, the precision of measurement; Described setting measurement parameter comprises amplitude measurement parameter, data procedures measurement parameter, spectrum measurement parameter, waveform measurement parameter, voltage measurement parameter.In-site measurement 8V watt of vibration, installs aforesaid speed pickup and electromagnetic interference shield 200 additional on 8V sensor stand, meanwhile, in Emonitor software, carry out for described speed pickup correlation parameter setting as shown in figure 12.
In the present embodiment, temporary sensory device is SHENCK VS080 type moving-coil speed sensor, under the different operating mode of unit, the time period that online 8V watt of display vibration is high, carry out the measurement of repeatedly off-line vibration data, and the off-line vibration data of measurement is kept in Enpac2500 data acquisition unit, described off-line vibration data is allowed to answer with aforementioned measurement parameter sequence pair respectively, finally, described Enpac2500 data acquisition unit is uploaded to Emonitor software database the off-line vibration data collected and carries out trend and spectrum analysis, result display 8V watt is shaken and is less than 1.0mm/s all the time, based on generator power frequency 25Hz in 10 ~ 1000Hz spectral range, with reference to Figure 13, this result is obviously different from on-line measurement result.And off-line vibration survey is carried out to 8H, 7V, 7H, its result is but consistent with on-line measurement.The difference of off-line vibration survey and on-line vibration metering system, is only that its pick-up link is different, therefore the pick-up link that in the present embodiment, off-line Vibration-Measuring System demonstrates 8V exists exception really.
In above-mentioned steps S3, adopt during finite element method and comprise the following steps:
: the geometric model setting up described sensor stand, and described geometric model is converted into finite element model (1).In this step, in parameterized geometric modeling system, the reach of design parameter is geometric model.But geometric model can not be directly used in and carry out analytical calculation, needs to be translated into finite element model, could be that analysis optimization program is used.In limited model-free is set up, the finite element analysis module of CAE software can be utilized---finite elements storehouse, material depot and related algorithm, constraint Processing Algorithm, finite element system Knockdown block, static(al), power, vibration, linearity and non-linearity solution Faku County.
(2): stress and strain model is carried out to set up finite element model.Stress and strain model type can adopt second order entity tetrahedron element.In most of Solid Modeling System of Solid, express in the machine of solid model and jointly completed by constructive solid geometry (CSG, constructive solid geometry) tree and boundary representation (B-Rep) structure.By boundary representation structure, the description of the stratification of enantiomorph geometric topology information can be obtained.This description covers all geometry topology objects of composition body, as body, face, ring, limit and summit etc., and the adjacent and attaching relation between them, this just provides carrier for the finite element grid control data of sensor stand and the definition of attribute data.Based on the finite element grid control data of boundary representation and the definition procedure of attribute data be: mutual definition finite element grid control data and attribute data, as the type of mesh generation size, load and size etc.; Select target geometry topology element, as body, face, ring, limit and summit etc.; Foundation definition data associate with target geometric element, and are attached in B-Rep data structure.
(3): the number of grid determining finite element model.Number of grid number will affect the precision of result of calculation and calculate the size of scale.In general, number of grid increases, and computational accuracy can increase, but calculating scale also can increase simultaneously, considers so should weigh two factors when determining number of grid.
Increasing number of grid when grid is less can make computational accuracy significantly improve, and computing time does not have large increase.When number of grid is increased to a certain degree, then when continuing to increase grid, precision improves very micro-, and computing time increases considerably.So the economy increasing grid should be noted.The result of calculation of two kinds of stress and strain model can be compared during practical application, if twice result of calculation difference is comparatively large, can continue to increase grid, then stop on the contrary calculating.
The type analyzing data should be considered when determining number of grid.When static analysis, if the distortion of computation structure, number of grid can lack.If need calculated stress, then should get relatively many grids when accuracy requirement is identical.Same in RESPONSE CALCULATION, calculated stress responds the grid number got and should respond than displacement calculating many.When computation structure natural dynamics behaviors, if be only calculate minority lower mode, less grid can be selected, if the mode order calculated is higher, then should select more grid.In thermal analyses, the thermograde of inside configuration is little, does not need a large amount of internal elements, at this moment can divide less grid.
(4) the grid density of finite element model: according to data variation gradient, is determined.Grid density refers to and adopts at structure different parts the grid varied in size, and this is the characteristic distributions in order to adapt to calculate data.Calculating the larger position (as stress raiser) of data variation gradient, in order to reflect data variation rule preferably, need to adopt the grid than comparatively dense.And calculating the less position of data variation gradient, for reducing scale of model, then should divide relatively sparse grid.Like this, total just shows the different stress and strain model form of density.
(5): according to the size of described sensor stand reality, material, welding and installation fixed form, definition boundary condition, and calculate natural frequency f.Control the condition of plane between research object, surface or interface place characteristic in model, determine the character of crossing over field, noncoherent boundary place thus.Boundary condition refers to the condition that solution of equations should meet on moving boundaries.
(6): adopt finite element analysis software to calculate natural frequency f.First the finite element model of finite element analysis software to the sensor stand of structure is adopted to carry out Analysis of Dynamic Characteristics, concrete principle is: described by the vibration Second Order with Constant Coefficients linear differential equation of sensor stand system by one group of many-degrees of freedom system, excitation is not considered during calculation on Natural Frequency, therefore equation is homogeneous, [M] is mass matrix, [C] is damping matrix, and [K] is stiffness matrix, x} is displacement vector:
If formula solution is 2.:
③
3. formula is brought into formula 2.:
With [M]
-14. multiplier, and does following replacement: system matrix [S]=[M]
-1[K] and system features value
:
([S]-λ
n[I]){X}={0} ⑤
Due to amplitude vector X} be not zero entirely (complete zero is not vibration), if make formula 5. set up, then:
([S]-λ
n[I])={0} ⑥
6. formula is frequency equation, eigenvalue λ
nsquare root be the n-th natural frequency of many-degrees of freedom system.Through the automatic computational analysis of finite element software, show that the first natural frequency of this model is 101.84Hz.
By above-mentioned steps, the present invention has finally shown that the natural frequency of sensor stand is 101.84Hz, close with power frequency 4 subharmonic 100Hz, causes sensor stand to resonate, so need the frequency changing sensor stand.
As an embodiment, in above-mentioned steps S4, the natural frequency changing sensor stand is specially and arranges the natural frequency f that balancing weight reduces sensor stand on sensor stand.Sensor stand is preset a natural frequency f avoiding resonating
n, according to formula
draw the preset quality of sensor stand, in formula, f
nfor the default natural frequency of sensor stand, ω
nfor angular velocity, k is the stiffness coefficient of sensor stand, and m is the preset quality of sensor stand; Deduct the initial quality of sensor stand with the preset quality m of sensor stand, obtain the quality of described balancing weight.
In the present embodiment, obtain 3 frequencys multiplication of generator, 3 frequencys multiplication of generator are 75Hz.Get 3 frequencys multiplication of generator and the intermediate value of power frequency and 50Hz, this intermediate value is set to the default natural frequency f of sensor stand
n.Theoretically, preset the value of natural frequency and can be located at arbitrary value between 3 frequencys multiplication and power frequency, but in order to default natural frequency not should too close to or 3 frequencys multiplication or power frequency, this is in order to avoid again there is resonance effect.According to the natural frequency expression formula of multivariant support
show that the preset quality of sensor stand is 9.85Kg.Deduct the initial quality 8.6Kg of sensor stand with preset quality 9.85Kg, the quality obtaining the balancing weight that need increase for sensor stand is 1.25Kg.
In the present embodiment, the object increasing balancing weight, mainly by increasing weight support frame, changes the vibration characteristics of whole sensor stand.Therefore, the material of balancing weight is selected to seem important.Preferably, the uniform solid metal block of the Material selec-tion of balancing weight; Meanwhile, in order to the balancing weight and sensor stand junction preventing increase corrodes, preferably identical with sensor stand material.
With reference to Figure 14, it is the structural representation after balancing weight 150 installation.In the present embodiment, the installation site of balancing weight 150 is sensor stand 100 bottom sides.Balancing weight 150 is fixed on this, mainly considers some factor following:
1, " vibration nodal point " position of position whether proximity transducer support;
2, the rigidity of original sensor support can whether be destroyed after installing;
3, whether scene easily installs;
4, can install firmly.
Comprehensive above 4 considerations, finally determine that the installation site of described balancing weight is back up pad 110 bottom sides.
By Figure 15, balancing weight 150 comprises clapboard 152 and is located at the counterweight body 151 on clapboard 152.During concrete installation, clapboard 152 is fixedly connected with the bottom of back up pad 110, and counterweight body 151 then plays counterweight effect.In the present embodiment, balancing weight 150 is designed to this structure, on the one hand, the end face that clapboard 152 tilts is convenient to be welded and fixed, and on the other hand, counterweight body 151 tactical rule, it is positioned at outside and does not affect sensor stand monnolithic case structure.
As specific embodiment, the installation of balancing weight 150, must ensure solid and reliable, to prevent from meeting accident in equipment runs the phenomenon come off, therefore selects the most firmly welding manner that itself and back up pad 110 are closely fixed.
In concrete enforcement, because 7V vibration does not have to occur larger fluctuation, therefore in overhaul, only increase balancing weight to 8V sensor stand, the result measured 8V sensor stand natural frequency after the balancing weight of increase and transformation, shows the natural frequency 73.8Hz transforming rear sensor stand.
As another embodiment, in above-mentioned steps S4, the natural frequency changing sensor stand is specially the rigidity of increase sensor stand to improve the natural frequency f of sensor stand 100.Concrete steps are:
First the stress high level zone of sensor stand 100 is determined.Known by the finite element analysis of sensor stand 100, maximum at the displacement of back up pad 110 foot, therefore judge sensor stand 100 upper stress high level zone should with the weld seam of back up pad 110 and contact plate 120 as starting point is to the extension of contact plate 120.Therefore sensor stand 100 rigidity promotes and should implement in this region.
In the stress high level zone of the sensor stand determined, in the following manner: increase the thickness of contact plate or set up gusset or transitional region is designed to slope shape etc., increasing the rigidity of sensor stand.It should be noted that in the design, prevent near natural frequency 5 frequencys multiplication that fall into generator power frequency after improving and 125Hz.
It should be noted that, natural frequency change method in the embodiment of the present invention, it is all feasible for passing through in theory to change quality and change rigidity.But consider from Reconstruction in field technique, change the balancing weight that quality only need weld certain mass, and avoid generator power frequency with regard to frequency multiplication.And change rigidity and need to weld certain thickness steel plate at web joint place, and wayward at actual welding quality in site.Therefore, in the present embodiment, preferential employing changes the natural frequency that quality changes sensor stand.
Owing to changing the natural frequency of sensor stand, make it avoid interval of resonance, thus avoid resonance to occur, reach the object eliminating pressurized-water reactor nuclear power plant Half Speed generator bearing shell vibration.
In practice, said method is adopted to solve the problem of eastern half speed turbine 8V abnormal vibration, save and vibrate due to falseness the cylinder of opening that high signal causes between daily and overhaul time and check generating dutation loss, open cylinder inspection work according to two units and calculate for each two days, save 5,000 ten thousand yuan.Meanwhile, this project is that company independently deals with problems, and saves and engages external experts expense 2,000,000 yuan.In addition, the solution of this problem, promotes the similar unit in each base by correlation experience, avoids Similar Problems to occur and maintenance down, the creation of value 100,000,000 yuan.The Resolving probiems of half speed turbine 8 watts of abnormal vibrations amounts to creates gene-ration revenue 1.5 hundreds of millions yuan.
These are only preferred embodiment of the present invention, not in order to limit the present invention, all any amendments done within the spirit and principles in the present invention, equivalent replacement and improvement etc., all should be included within protection scope of the present invention.
Claims (16)
1. a disposal route for nuclear power station Turbo-generator Set, is characterized in that: comprise the following steps:
S1: the axle of rear end vertical direction gathering generator shakes and watt to shake, carrying out the spectrogram that spectrum analysis obtains the rear end vertical direction of generator, to shake power frequency component b by finding out the shake fundamental component frequency a of value and the Distribution value that watt to shake, axle of axle within the scope of 10 ~ 1000Hz in spectrogram
1and the component c at fundamental component frequency a place
1;
The axle of rear end horizontal direction gathering generator shakes and watt to shake, and carries out the spectrogram that spectrum analysis obtains the rear end horizontal direction of generator, to shake power frequency component b by finding out axle in spectrogram
2and the component c at fundamental component frequency a place
2;
The axle of front end vertical direction gathering generator shakes and watt to shake, and carries out the spectrogram that spectrum analysis obtains the front end vertical direction of generator, by the component c found out in spectrogram at fundamental component frequency a
3;
The axle of front end horizontal direction gathering generator shakes and watt to shake, and carries out the spectrogram that spectrum analysis obtains the front end horizontal direction of generator, by the component c found out in spectrogram at fundamental component frequency a
4;
S2: compare b respectively
1with b
2, c
1with c
2, c
3, c
4whether close; If b
1with b
2close, c
1with c
2, c
3, c
4keep off, judge that the vibration of the rear end vertical direction of generator comes from pick-up link abnormal, continue following step S3; If b
1with b
2keep off, c
1with c
2, c
3, c
4close, judge that the vibration of the rear end vertical direction of generator comes from rotor unbalance or support stiffness is inadequate, then check rotor balancing or increase support stiffness;
S3: check whether on-line vibration sensor and/or cable cause pick-up link abnormal by electromagnetic interference (EMI), if so, arrange shield assembly to eliminate electromagnetic interference (EMI); If not, judge the abnormal resonance coming from sensor stand of pick-up link, adopt the natural frequency f of finite element method calculating sensor support;
S4: the natural frequency f changing sensor stand avoids resonance, eliminates pick-up link abnormal, thus eliminates bearing shell vibration.
2. the disposal route of nuclear power station Turbo-generator Set as claimed in claim 1, is characterized in that: in step s3, and whether on-line vibration sensor and/or cable cause pick-up link abnormal by electromagnetic interference (EMI) to adopt signal shielding test to check,
Described signal shielding test comprises the following steps:
Sa: speed pickup is set on sensor stand, and electromagnetic interference shield is set on described speed pickup;
Sb: the parameter comparison that the parameter and the described on-line vibration sensor not doing shielding processing of doing the speed pickup collection of described electromagnetic interference shield process are gathered, if comparison result is consistent, then whether eliminating on-line vibration sensor and/or cable cause pick-up link abnormal by electromagnetic interference (EMI), if comparison result is inconsistent, then illustrate that on-line vibration sensor and/or cable cause by electromagnetic interference (EMI) pick-up link abnormal, then carry out arranging shield assembly to eliminate the step of electromagnetic interference (EMI) to linearly coupled sensor and/or cable in S3.
3. the disposal route of nuclear power station Turbo-generator Set as claimed in claim 2, it is characterized in that: in step Sa, described electromagnetic interference shield comprises the upper radome of upper and lower docking and lower radome, described speed pickup is placed in space that described upper radome and lower radome enclose, the extension line of described speed pickup is twisted-pair feeder, described twisted-pair feeder outer wrapping double shield layer.
4. the disposal route of nuclear power station Turbo-generator Set as claimed any one in claims 1 to 3, it is characterized in that: after the vibration of the rear end vertical direction judging generator comes from pick-up link exception, before whether investigation causes pick-up link abnormal by on-line vibration sensor and/or cable by electromagnetic interference (EMI), off-line measurement is carried out to the vibration of the rear end vertical direction of generator, obtain axle within the scope of 10 ~ 1000Hz to shake the fundamental component frequency d of value and the Distribution value that watt to shake, and whether compare d and a consistent, if d and a is consistent, then get rid of pick-up link abnormal, if d and a is inconsistent, then confirm that pick-up link is abnormal.
5. the disposal route of nuclear power station Turbo-generator Set as claimed in claim 4, is characterized in that: when carrying out off-line measurement, comprise the following steps:
One temporary sensory device is arranged at generator ' s cover first half convex edge vertically locate;
Measurement parameter sequence is set up in Emonitor software;
Described measurement parameter sequence is downloaded in data acquisition unit;
The data of temporary sensory device repeatedly off-line measurement are saved to described data acquisition unit, and are uploaded to Emonitor software database by data acquisition unit and carry out trend and spectrum analysis, obtain above-mentioned fundamental component frequency d.
6. the disposal route of nuclear power station Turbo-generator Set as claimed in claim 5, is characterized in that: in described measurement parameter sequence, define measurement data option, arrange and measure collection definition and setting measurement parameter;
Described measurement data option comprises measures type, measurement wave filter, measuring unit; Described arrange measure gather definition comprise sensor type, measuring-signal type of detection, the scope of survey frequency, the precision of measurement; Described setting measurement parameter comprises amplitude measurement parameter, data procedures measurement parameter, spectrum measurement parameter, waveform measurement parameter, voltage measurement parameter.
7. the disposal route of nuclear power station Turbo-generator Set as claimed any one in claims 1 to 3, is characterized in that: in step S3, adopts during finite element method and comprises the following steps:
: the geometric model setting up described sensor stand, and described geometric model is converted into finite element model (1);
(2): stress and strain model is carried out to set up finite element model;
(3): the number of grid determining finite element model;
(4) the grid density of finite element model: according to data variation gradient, is determined;
(5): according to the size of described sensor stand reality, material, welding and installation fixed form, definition boundary condition.
(6): adopt finite element analysis software to calculate natural frequency f.
8. the disposal route of nuclear power station Turbo-generator Set as claimed in claim 7, it is characterized in that: in above-mentioned steps (6), when adopting finite element analysis software, described by the vibration Second Order with Constant Coefficients linear differential equation of sensor stand system by one group of many-degrees of freedom system, do not consider excitation, equation is homogeneous, [M] is mass matrix, [C] is damping matrix, and [K] is stiffness matrix, x} is displacement vector:
Formula frequency equation can be derived: ([S]-λ by formula (1)
n[I])={ 0} (2)
System matrix [S]=[M] in formula (2)
-1[K], system features value
eigenvalue λ
nsquare root be n natural frequency of many-degrees of freedom system.
9. the disposal route of nuclear power station Turbo-generator Set as claimed in claim 1, is characterized in that: in above-mentioned steps S4, and the natural frequency changing sensor stand is specially and arranges the natural frequency f that balancing weight reduces sensor stand on sensor stand.
10. the disposal route of nuclear power station Turbo-generator Set as described in claim 9, is characterized in that: sensor stand is preset a natural frequency f avoiding resonating
n, according to formula
draw the preset quality of sensor stand, in formula, f
nfor the default natural frequency of sensor stand, ω
nfor angular velocity, k is the stiffness coefficient of sensor stand, and m is the preset quality of sensor stand; Deduct the initial quality of sensor stand with the preset quality m of sensor stand, obtain the quality of described balancing weight.
11. the disposal route of the nuclear power station Turbo-generator Set as described in claim 9 or 10, is characterized in that: described sensor stand comprises that the back up pad, the level that vertically arrange are located at the contact plate of side, back up pad top, level is located at back up pad opposite side, and watt to shake measuring mechanism and the axle be located at below the measuring mechanism that watt to shake shakes measuring mechanism.
The disposal route of 12. nuclear power station Turbo-generator Set as claimed in claim 11, is characterized in that: described balancing weight adopts and is welded and fixed the bottom that mode is fixed on the back up pad of described sensor stand.
The disposal route of 13. nuclear power station Turbo-generator Set as described in claim 9 or 10, it is characterized in that: described balancing weight is uniform solid metal block, and material is identical with described sensor stand material.
The disposal route of 14. nuclear power station Turbo-generator Set as described in claim 9 or 10, is characterized in that: described balancing weight comprises clapboard and is located at the counterweight body on described clapboard.
The disposal route of 15. nuclear power station Turbo-generator Set as claimed any one in claims 1 to 3, it is characterized in that: in above-mentioned steps S4, the natural frequency changing sensor stand is specially the rigidity of increase sensor stand to improve the natural frequency f of sensor stand.
The disposal route of 16. nuclear power station Turbo-generator Set as described in claim 15, it is characterized in that: the stress high level zone determining sensor stand, by increasing thickness or set up gusset or become slope shape to increase the rigidity of sensor stand this zone design in this region.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310746887.4A CN104564182B (en) | 2013-10-25 | 2013-12-30 | Processing method for steam turbine generator unit of nuclear power station |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2013105140668 | 2013-10-25 | ||
| CN201310514066 | 2013-10-25 | ||
| CN201310746887.4A CN104564182B (en) | 2013-10-25 | 2013-12-30 | Processing method for steam turbine generator unit of nuclear power station |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104564182A true CN104564182A (en) | 2015-04-29 |
| CN104564182B CN104564182B (en) | 2017-04-19 |
Family
ID=53081153
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310746887.4A Active CN104564182B (en) | 2013-10-25 | 2013-12-30 | Processing method for steam turbine generator unit of nuclear power station |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104564182B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107063448A (en) * | 2017-06-09 | 2017-08-18 | 江苏中信博新能源科技股份有限公司 | A kind of device and method of testing for simulating photovoltaic mount vibration frequency |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4282756A (en) * | 1979-07-10 | 1981-08-11 | Westinghouse Electric Corp. | Apparatus for estimating the strain on an inaccessible portion of a rotating shaft |
| US6192758B1 (en) * | 1998-12-14 | 2001-02-27 | Kang Huang | Structure safety inspection |
| CN101173877A (en) * | 2007-12-04 | 2008-05-07 | 四方电气(集团)有限公司 | Method for measuring mechanical fatigue of steam turbine generator unit shaft system |
| CN103226054A (en) * | 2013-04-26 | 2013-07-31 | 北京理工大学 | Experimental verification method for identifying modal parameter of variable mass structure |
-
2013
- 2013-12-30 CN CN201310746887.4A patent/CN104564182B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4282756A (en) * | 1979-07-10 | 1981-08-11 | Westinghouse Electric Corp. | Apparatus for estimating the strain on an inaccessible portion of a rotating shaft |
| US6192758B1 (en) * | 1998-12-14 | 2001-02-27 | Kang Huang | Structure safety inspection |
| CN101173877A (en) * | 2007-12-04 | 2008-05-07 | 四方电气(集团)有限公司 | Method for measuring mechanical fatigue of steam turbine generator unit shaft system |
| CN103226054A (en) * | 2013-04-26 | 2013-07-31 | 北京理工大学 | Experimental verification method for identifying modal parameter of variable mass structure |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107063448A (en) * | 2017-06-09 | 2017-08-18 | 江苏中信博新能源科技股份有限公司 | A kind of device and method of testing for simulating photovoltaic mount vibration frequency |
| CN107063448B (en) * | 2017-06-09 | 2024-01-19 | 江苏中信博新能源科技股份有限公司 | Device for simulating vibration frequency of photovoltaic bracket and testing method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104564182B (en) | 2017-04-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Daneshi-Far et al. | Review of failures and condition monitoring in wind turbine generators | |
| CN102221651B (en) | Fault on-line diagnosis and early warning method of flameproof dry-type transformer for mine | |
| CN1026438C (en) | Abnormality diagnosing system and method for high voltage power apparatus | |
| CN101459334B (en) | Electrical power system failure information obtaining method | |
| CN104748838B (en) | Transformer Winding based on finite element analysis, which loosens, judges system and method | |
| CN104019952A (en) | Vibration detecting method for reactor fault diagnosis | |
| CN109374273A (en) | Torsional Vibration of Turbine Generator Rotor and fault simulation multi-function test stand and test method | |
| Thie | Core motion monitoring | |
| CN102914362B (en) | Separating method for vibration signals of transformer winding and iron core | |
| CN104597425A (en) | Electric examination platform suitable for GIS (geographic information system) electronic transformer | |
| CN102778633A (en) | Method for selecting vibration sensitive area of power transformer tank surface winding | |
| CN204241500U (en) | Buchholz relay oil stream flow velocity acquisition system | |
| CN204359925U (en) | One is applicable to the charged evaluating platform of GIS electronic mutual inductor | |
| CN115097745A (en) | Transformer bushing fault diagnosis system based on digital twinning and operation method | |
| CN104564182B (en) | Processing method for steam turbine generator unit of nuclear power station | |
| CN208999082U (en) | Torsional Vibration of Turbine Generator Rotor and fault simulation multi-function test stand | |
| CN106443257A (en) | System for monitoring state of EHV (extra-high voltage) transformer based on vibration | |
| CN104535928B (en) | Direct wind-driven generator simulator stand and state monitoring apparatus | |
| CN105823549A (en) | Magnetic damping-based transmission line tower vibration sensor, monitoring system and monitoring method | |
| Di Lorenzo et al. | Structural Health Monitoring strategies based on the estimation of modal parameters | |
| JP2016509234A (en) | Method and apparatus for measuring tube pressure | |
| Zhang | On the changes in dynamic behavior produced by the hydraulic turbine runner damage | |
| CN103033252A (en) | Collection method for vibration signal on surface of transformer body | |
| CN203742681U (en) | Vibration picking device of steam turbine generator unit of nuclear power plant | |
| Thakur et al. | A review study on the improvement of stator frame design and prediction of electromagnetic vibration of hydro generators |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |