CN102768101A - Vibration testing device for hydropower unit in hydropower station and vibration attenuation implementing method of vibration testing device - Google Patents

Abstract

The invention discloses a vibration testing device for a hydropower unit in a hydropower station, comprising four horizontal vibration sensors, a magnetic approach switch, a magnetic sheet type fixed reference point and a signal acquisition instrument, wherein the four horizontal vibration sensors are respectively fixed on an upper rack and a lower rack which are used as two supporting legs; the magnetic approach switch is fixed on the upper rack; the magnetic sheet type fixed reference point is fixed on a rotating shaft; and the horizontal vibration sensors and the magnetic approach switch are respectively connected with the signal acquisition instrument. A vibration attenuation implementing method of the vibration testing device comprises the following steps of: starting up the hydropower unit to test sensor signals of the hydropower unit under different loads; determining an unbalance mass position according to a test curve; carrying out equal-mass weight distribution on the upper end surface and the lower end surface of a rotor of the unit, and testing by changing mass of a distributed weight in equal proportion; and determining the masses of the distributed weights on the upper end surface and the lower end surface of the rotor of the hydropower unit according to the vibration test amplitude values of the two weight distributions. The vibration testing device is simple in structure, and the vibration attenuation implementing method is easy to implement, high in efficiency and capable of synchronously reducing vibration of the hydropower unit caused by a machine, a water flow and an unbalanced magnetic force so as to prolong the service life of the hydropower unit.

Description

A kind of power station Hydraulic Power Unit vibration-testing apparatus and vibration damping implementation method thereof

Affiliated technical field

The invention belongs to power station Hydraulic Power Unit vibration-testing and control, particularly a kind of power station Hydraulic Power Unit vibration-testing apparatus and vibration damping implementation method thereof.

Background technology

On August 17th, 2009; Serious accident takes place in Sa Yang-Shu Shensike power station, near the 2# unit, produces a thundering noise earlier, and 2# water-turbine top cover and rotor penetrate subsequently; Water column sprays into main building from the cavity of the hydraulic turbine, finally causes water logging factory building, fatal crass's heavy consequence.The past, if not forgotten, can serve as a guide for the future, and resulting caution should cause the attention of China's water conservancy industry from Sa Yang-Shu Shensike power station serious accident.The accident post analysis, the vibration that exceeds standard of unit is one of major reason that causes this accident.

The factor that causes Hydraulic Power Unit vibration mainly contains three types of machineries, waterpower, electromagnetism, and the unit vibration that three types of factors cause interknits, interacts.For example; When flow evokes the unit rotor oscillation; Between generator amature and stator, can cause air gap asymmetric; The asymmetric vibration that can aggravate the unit rotating part again of magnetic pull that produces therefrom, and the rotor motion state changes and must the flow field and the generator electromagnetic field of the hydraulic turbine be exerted an influence.

Carry out dynamic balance running, on electric generating set rotor, carry out reasonable, effective counterweight, can effectively solve because the unit vibration problem that unit rotating part non-uniform mass causes.The essence of dynamic balance running is to find out the unbalance mass, and the position of rotor, at present installation company, three test mass graphing methods of the many employings of unit maintenance mechanism.This method more complicated, and need the multiple switching unit, generally be no less than 5 times.And test the time do not consider that unit load changes the influence that brings, and makes this experiment can not at utmost reduce the Hydraulic Power Unit vibration.

Summary of the invention

The object of the invention is intended to above-mentioned existing problems; A kind of power station Hydraulic Power Unit vibration-testing apparatus and vibration damping implementation method thereof are provided, and this proving installation can reduce the Hydropower Unit vibration that machinery, current, electromagnetic unbalance power cause synchronously, considers the influence of unit load variation, water flow field variation etc.; More effectively reduce and control the vibration of Hydraulic Power Unit; The number of times of starting shooting when this method of testing can reduce dynamic balance running reduces testing cost, improves testing efficiency.

Technical scheme of the present invention:

A kind of power station Hydraulic Power Unit vibration-testing apparatus; Comprise horizontal vibration sensor, magnet proximity switch, magnetic sheet permanent datum and signal sampler; The horizontal vibration sensor be provided with altogether four and be separately fixed at be positioned at above the rotor with following two supporting legs of upper and lower frame on, the horizontal vibration sensor orientation that two horizontal vibration sensors that install in the outside of each frame are mutually on 90 degree and the upper and lower frame is corresponding consistent; Magnet proximity switch is fixed on the upper spider near rotating shaft place; The magnetic sheet permanent datum is fixed in the rotating shaft and with magnet proximity switch and is on the same horizontal line; The distance of magnet proximity switch and magnetic sheet permanent datum is 0.5-2cm; Make that switch is an opening state when this RP is passed through magnet proximity switch, switch is a closure state when leaving; The horizontal vibration sensor is connected with signal sampler through lead respectively with magnet proximity switch.

The vibration damping implementation method of a kind of said power station Hydraulic Power Unit vibration-testing apparatus, step is following:

1) stopped status installation testing device starts Hydraulic Power Unit then to rated speed, the on-load that is incorporated into the power networks, the sensor signal of Hydraulic Power Unit under test and the record different load;

2) select horizontal vibration amplitude maximum duty, confirm the unbalance mass, position according to crest, wave trough position and the magnet proximity switch pulse signal position of the vibration amplitude signal curve of horizontal vibration sensor test;

3) stop unit operation then, the quality counterweight such as carry out in relevant position, hydroelectric generator group rotor upper and lower end face, start unit to vibration amplitude maximum duty, test is the record coherent signal also;

4) then stop unit operation, equal proportion changes weight mass, starts unit to vibration amplitude maximum duty, test and record coherent signal;

5) at last according to the vibration-testing amplitude of twice counterweight, confirm the counterweight amount of Hydraulic Power Unit rotor upper and lower end face, stop unit operation, carry out counterweight according to calculating the counterweight value, completion reduces Hydraulic Power Unit vibration work, and unit recovers normal operation.

Beneficial effect of the present invention:

This proving installation is simple in structure, and oscillation damping method is easy to implement, and efficient is high; Can reduce the Hydraulic Power Unit vibration that machinery, current, electromagnetic unbalance power cause synchronously, classic method is simpler relatively, and the factor of consideration is more; Can effectively reduce the vibration amplitude of Hydraulic Power Unit, increase the scope of the efficient operational area of unit, and the serviceable life that prolongs unit; Testing cost is low, has very high practical value.

Description of drawings

Fig. 1 is this proving installation synoptic diagram.

Fig. 2 is this proving installation schematic top plan view.

Among the figure: 1. upper spider 2. lower bearing brackets 3. rotor 4-I, 4-II, 4-III, 4-IV. horizontal vibration sensor 5. magnet proximity switchs 6. rotating shafts 7. magnetic sheet permanent datums 8. signal samplers 9. leads

Fig. 3 is to be the phase place comparative analysis figure of reference point drafting with upper spider directions X horizontal vibration sensor.

Embodiment

Embodiment:

A kind of power station Hydraulic Power Unit vibration-testing apparatus; Comprise horizontal vibration sensor 4-I, 4-II, 4-III, 4-IV, magnet proximity switch 5, magnetic sheet permanent datum 7 and signal sampler 8; The horizontal vibration sensor is provided with four 4-I, 4-II, 4-III, 4-IV altogether and is separately fixed at and is positioned at above the rotor 3 and on following 1,2 two supporting legs of upper and lower frame, the horizontal vibration sensor orientation that two horizontal vibration sensors that install in the outside of each frame 1,2 are mutually on 90 degree and the upper and lower frame 1,2 is corresponding consistent; Magnet proximity switch 5 is fixed on the upper spider 1 near rotating shaft 6 places; Magnetic sheet permanent datum 7 is fixed in the rotating shaft 6 and with magnet proximity switch 5 and is on the same horizontal line; When this RP 7 was passed through magnet proximity switch 5, switch 5 was an opening state, and switch 5 is closure state when leaving; Horizontal vibration sensor 4-I, 4-II, 4-III, 4-IV and magnet proximity switch 5 are connected with signal sampler 8 through lead 9 respectively.

The vibration damping implementation method of this power station Hydraulic Power Unit vibration-testing apparatus, Hydraulic Power Unit capacity 200,000 kW, counterweight radius 3m, rated speed is 120r/min, step is following:

1) Hydraulic Power Unit is out of service, in orthogonal two horizontal directions of last lower bearing bracket (directions X and Y direction) a horizontal vibration sensor (DPS-0.35-5-H) is installed respectively; Near the commentaries on classics place of taking out one magnet proximity switch (DZJC-2) is installed at the upper spider directions X, and in rotating shaft, is installed and fixed RP, magnet proximity switch 5 is 0.5cm with the distance of magnetic sheet permanent datum 7; Horizontal vibration sensor, magnet proximity switch are connected with signal sampler (NI PXI-6255 more Function Data Collect System) through lead respectively.

2) start Hydraulic Power Unit, the on-load that is incorporated into the power networks, respectively in the stable operation 5 minutes down of 2,4,6,8,10,12,14,16,18,200,000 kW load, each load of signal sampler record is the fluctuating signal of vibration amplitude and on-off element generation down; Draw the lower sensor vibration amplitude change procedure curve map of respectively loading, select the maximum corresponding load condition of vibration amplitude, this time implement through confirming that relatively the corresponding operating mode of maximum vibration amplitude is 80,000 kW; With upper spider directions X horizontal vibration sensor is reference point; Draw phase place comparative analysis figure, as shown in Figure 3, leading RP 54 degree of phase place of unbalance mass, can be confirmed in pulse signal and vibration amplitude position from figure; Utilize the test data of other three sensors; Also draw phase place comparative analysis figure, check the phase place of unbalance mass,, guarantee the result accurately.

3) unit is out of service; Hydraulic Power Unit upper and lower end face counterweight radius in the unbalance phase of confirming 180 degree directions is the relevant position of 3m; Counterweight 15kg starts the corresponding operating mode of unit to maximum vibration amplitude respectively, signal sampler record coupled vibration amplitude signal.

4) unit is out of service, original balance position in the Hydraulic Power Unit upper and lower end face, and counterweight 30kg starts unit to 80,000 kW that load respectively, signal sampler record coupled vibration amplitude signal.

5) this time implementing to choose on the directions X lower bearing bracket test data analyzes.Suppose that the radial rigidity that goes up lower carriage is constant, the mount vibration magnitude that the variation of unbalance mass, causes after the consideration counterweight, according to Hooke's law and equilibrium of forces, each needs counterweight 60kg, 80kg can to calculate this hydropower unit upper and lower end face.Concrete formula is following:

F=kx

F is a load in the formula, and K is a rigidity, and X is a shift value.

According to the mass change of twice counterweight, adopt the relation between above-mentioned formula row centrifugal force and the test shift value to obtain:

$\mathrm{\Δm}{\mathrm{\ω}}^{2}r=k_1(x_1^2-x_1^1)=k_2(x_2^2-x_2^1)$

Twice counterweight of △ m is of poor quality in the formula; The tarnsition velocity of ω unit; R is the counterweight radius; k ₁, k ₂Be respectively upper spider and lower bearing bracket radial rigidity;

Be respectively the displacement amplitude of the upper spider counterweight first time and secondary test;

Be respectively the displacement amplitude of the lower bearing bracket counterweight first time and secondary test.

Can calculate upper spider and lower bearing bracket radial rigidity k according to following formula ₁, k ₂According to the displacement amplitude test result before the counterweight, adopt following formula then:

${\mathrm{<figure-callout\; id="1"\; label="m"\; filenames="HDA00001920349300011.png,HDA00001920349300022.png"\; state="\{\{state\}\}">m</figure-callout>}}_1{\mathrm{\&omega;}}^{2}r=k_1{x}_1^0$

${\mathrm{<figure-callout\; id="2"\; label="m"\; filenames="HDA00001920349300011.png"\; state="\{\{state\}\}">m</figure-callout>}}_2{\mathrm{\&omega;}}^{2}r=k_2{x}_2^0$

m ₁, m ₂Be the required weight mass of last lower bearing bracket; Be respectively lower bearing bracket under the corresponding operating mode of unit to maximum vibration amplitude, not the displacement amplitude of horizon sensor test during counterweight.

Stop unit operation, the original balance position in Hydraulic Power Unit upper and lower end face, difference counterweight 60kg and 80kg, unit recover normal operation.

Claims (2)

1. power station Hydraulic Power Unit vibration-testing apparatus; It is characterized in that: comprise horizontal vibration sensor, magnet proximity switch, magnetic sheet permanent datum and signal sampler; The horizontal vibration sensor be provided with altogether four and be separately fixed at be positioned at above the rotor with following two supporting legs of upper and lower frame on, the horizontal vibration sensor orientation that two horizontal vibration sensors that install in the outside of each frame are mutually on 90 degree and the upper and lower frame is corresponding consistent; Magnet proximity switch is fixed on the upper spider near rotating shaft place; The magnetic sheet permanent datum is fixed in the rotating shaft and with magnet proximity switch and is on the same horizontal line; The distance of magnet proximity switch and magnetic sheet permanent datum is 0.5-2cm; Make that switch is an opening state when this RP is passed through magnet proximity switch, switch is a closure state when leaving; The horizontal vibration sensor is connected with signal sampler through lead respectively with magnet proximity switch.

2. vibration damping implementation method of power station Hydraulic Power Unit vibration-testing apparatus according to claim 1 is characterized in that step is following:

1) stopped status installation testing device starts Hydraulic Power Unit then to rated speed, the on-load that is incorporated into the power networks, the sensor signal of Hydraulic Power Unit under test and the record different load;

2) select horizontal vibration amplitude maximum duty, confirm the unbalance mass, position according to crest, wave trough position and the magnet proximity switch pulse signal position of the vibration amplitude signal curve of horizontal vibration sensor test;

3) stop unit operation then, the quality counterweight such as carry out in relevant position, hydroelectric generator group rotor upper and lower end face, start unit to vibration amplitude maximum duty, test is the record coherent signal also;

4) then stop unit operation, equal proportion changes weight mass, starts unit to vibration amplitude maximum duty, test and record coherent signal;

5) at last according to the vibration-testing amplitude of twice counterweight, confirm the counterweight amount of Hydraulic Power Unit rotor upper and lower end face, stop unit operation, carry out counterweight according to calculating the counterweight value, completion reduces Hydraulic Power Unit vibration work, and unit recovers normal operation.

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