CN109271684A - It is a kind of for pump turbine removal of load process Dynamic Characteristics Analysis Method - Google Patents

It is a kind of for pump turbine removal of load process Dynamic Characteristics Analysis Method Download PDF

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CN109271684A
CN109271684A CN201810995376.9A CN201810995376A CN109271684A CN 109271684 A CN109271684 A CN 109271684A CN 201810995376 A CN201810995376 A CN 201810995376A CN 109271684 A CN109271684 A CN 109271684A
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ingredient
pressure signal
particular frequencies
guide vane
fourier transform
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CN109271684B (en
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刘全忠
苏文涛
夏煜星
王兴茹
徐科繁
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Harbin Institute of Technology
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    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00—Computer-aided design [CAD]
    • G06F30/20—Design optimisation, verification or simulation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03B—MACHINES OR ENGINES FOR LIQUIDS
    • F03B13/00—Adaptations of machines or engines for special use; Combinations of machines or engines with driving or driven apparatus; Power stations or aggregates
    • F03B13/06—Stations or aggregates of water-storage type, e.g. comprising a turbine and a pump
    • 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
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/20—Hydro energy
    • 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
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/16—Mechanical energy storage, e.g. flywheels or pressurised fluids

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  • General Physics & Mathematics (AREA)
  • Hydraulic Turbines (AREA)

Abstract

The invention proposes a kind of for pump turbine in the Dynamic Characteristics Analysis Method of removal of load process, belongs to pump turbine specificity analysis technical field.Analysis method of the present invention carries out boundary condition setting according to unsteady state flow field computation of the pump turbine unit rotor kinetics equation to Transients of Load Rejection first and calculates, detailed time-frequency characteristic is carried out to the pressure fluctuation of component measuring points different in pump turbine unit external characteristics and entire basin later to analyze, four kinds of particular frequencies ingredients a, b, c and d for causing pump turbine external characteristics unstable are obtained, and tentatively their excitation source position is analyzed, the inducement of particular frequencies ingredient is given from the angle of external characteristics later.Finally the flow field in Transients of Load Rejection is analyzed, the concrete reason of particular frequencies ingredient formation is given in terms of vorticity and draft tube fluidised form two.

Description

It is a kind of for pump turbine removal of load process Dynamic Characteristics Analysis Method
Technical field
The present invention relates to a kind of for pump turbine in the Dynamic Characteristics Analysis Method of removal of load process, belongs to water pump water Turbine specificity analysis technical field.
Background technique
The most important component part of hydroenergy storage station is pump turbine, due to the dual angle with water pump and the hydraulic turbine Color, pump turbine can undergo complicated transient process, research of the China to pump turbine transient process in the process of running It starts late, and the characteristic of transient process is to measure one of the key factor of hydroenergy storage station stability, so to water pump water The transient process of turbine is in depth studied the optimization design to pump turbine, safely and steadily runs and give full play to it Economic benefit has critically important practical meaning in engineering.
The existing characteristic analysis method for pump turbine operational process is substantially chosen a series of operating conditions and is clicked through Four quadrants of covering are removed in the calculating of row stable state, are on the other hand concentrated mainly on the anti-area S of the hydraulic turbine and water pump hump zone.But it is the absence of pair Frequent transitions, pressure fluctuation characteristics and various special flowings in the continuous process of pump turbine transient process between operating condition Development law research and analyse.The research of transient process about the hydraulic turbine is concerned with how using CFD Numerical-Mode Quasi- external characteristics during accurately realizing hydraulic turbine transitory process and research hydraulic turbine transitory, and for actually water Violent variation can occur for external characteristics during turbine transitory, the few relevant analyses of inducement that these variations generate.
Summary of the invention
The present invention is above-mentioned insufficient in the prior art in order to solve, and proposes one kind for pump turbine in removal of load process Dynamic Characteristics Analysis Method, the technical solution taken is as follows:
A kind of Dynamic Characteristics Analysis Method for pump turbine in removal of load process, the Dynamic Characteristics Analysis Method Include:
Step 1: water pump water is established by zoning of spiral case, fixed guide vane, movable guide vane, runner and draft tube respectively The Three dimensional transient computation model of turbine, using computational domain of the Meshing Method to the Three dimensional transient computation model carry out from It dissipates, and is verified by grid independence and determine grid node number；
Step 2: respectively to spiral case, fixed guide vane, movable guide vane, runner and the draft tube in Three dimensional transient computation model Boundary condition, calculating and setting and the turbulence model of five zonings are configured；
Step 3: calculating runner revolving speed according to rotor dynamics, and removal of load is carried out based on the runner revolving speed Transient calculates；
Step 4: pressure-measuring-point is arranged in the full basin of the pump turbine, passes through the time domain specification of pressure-measuring-point The pressure fluctuation characteristics for obtaining pump turbine removal of load process, using the pressure fluctuation characteristics of acquisition to pump turbine The dynamic characteristic parameter of removal of load process is analyzed, and is determined in the pressure signal of the pressure-measuring-point comprising particular frequencies ingredient A, particular frequencies ingredient b, particular frequencies ingredient or particular frequencies ingredient d, and primarily determine that pressure signal includes each ingredient Energized position source；
Step 5: pass through the dynamic characteristic parameter of pump turbine removal of load process and pump turbine removal of load process The synthesis external characteristics of flow and runner torque external characteristics and removal of load process determines the particular frequencies ingredient a, particular frequencies The inducement of ingredient b, particular frequencies ingredient c and particular frequencies ingredient d；
Step 6: pump turbine pressure signal spectrogram during the Vorticity Distribution and removal of load of pump turbine is utilized Fluidised form in vorticity evolution process and draft tube during pump turbine removal of load is analyzed, from vorticity evolution process and Particular frequencies ingredient a, particular frequencies ingredient b, particular frequencies ingredient c and particular frequencies ingredient are obtained in draft tube in terms of fluidised form two The concrete reason that d is generated, and then pump turbine is completed in the dynamic analysis of removal of load procedure.
Further, the setting up procedure of boundary condition, calculating and setting described in step 2 and turbulence model includes:
Step 1: respectively to spiral case, fixed guide vane, movable guide vane, runner and the draft tube in Three dimensional transient computation model The boundary condition of five zonings is configured, and is specifically configured to: spiral case inlet section boundary condition setting is Pressure- inlet；The boundary condition of draft tube outlet section is set as Pressure-outlet；Runner region uses sliding mesh model；Snail Shell outlet and fixed guide vane import, fixed guide vane outlet and movable guide vane import, movable guide vane outlet and runner import, runner go out Mouth and draft tube import are set as 4 pairs of interface boundary conditions；Field at the beginning of calculating stable state using the parameter of initial operating point, makees The initialization condition calculated for subsequent transient state；
Step 2: being configured to turbulence model, be specifically configured to: turbulence model uses RNGk- ε model, and uses SIMPLEC algorithm carries out numerical solution to Fluid Control Equation；
Step 3: carrying out calculating and setting, be specifically configured to: the convergence residual error of all parameters is disposed as in numerical value calculating 1.0e-5；In unsteady state circumstance, for 0.0017 second, the greatest iteration step number of each time step was set as the time step used 30 steps.
Further, the calculating process of runner revolving speed described in step 3 includes:
According to rotor dynamics, rotor angular momentum equilibrium equation is obtained, the rotor angular momentum equilibrium equation is as follows:
Wherein, resultant moment suffered by M --- rotor (Nm)；
J --- rotor moment of inertia (kgm2)；
ω --- rotor velocity (rad/s)；
T --- the time (s)；
By the rotor angular momentum equilibrium equation carry out it is discrete, with C language will be discrete after equation form be compiled into Fluent User-Defined Functions load compiling, to control the rotation of runner, and in each time step in Fluent It is called in iterative process, exports the revolving speed and torque parameter of each step.
Further, the position of pressure-measuring-point described in step 4 included: in the plane of tandem cascade intermediate altitude, It is respectively arranged spiral case measuring point SC-MP-1~4, fixed guide vane entrance measuring point sv-1~6, movable guide vane entrance clockwise Measuring point gv-1~20, without leaf area measuring point vl-1~20, runner entrance measuring point rn-1~9: cross movable guide vane close to base ring height In plane, it is respectively arranged fixed guide vane entrance measuring point sv-dn-1~6, movable guide vane entrance measuring point gv- clockwise Dn-1~20, without leaf area measuring point vl-dn-1~20, runner entrance measuring point rn-dn-1~9: cross movable guide vane close to cap height, Be respectively arranged clockwise fixed guide vane entrance measuring point sv-up-1~6, movable guide vane entrance measuring point gv-up-1~20, No leaf area measuring point vl-up-1~20, runner entrance measuring point rn-up-1~9: three different cross sections for crossing draft tube are respectively arranged prison Measuring point DT1~12.
Further, the specific steps of the pressure fluctuation characteristics of pump turbine removal of load process are obtained described in step 4 Are as follows:
Step 1: the time-domain diagram for obtaining the pressure signal without the monitoring point Ye Qu vl1 is calculated by three-dimensional CFD, and to the nothing The pressure signal of the monitoring point Ye Qu vl1 carries out Fast Fourier Transform (FFT), and it is corresponding to obtain the pressure signal without the monitoring point Ye Qu vl1 Fast Fourier Transform (FFT) is as a result, by the Fast Fourier Transform (FFT) as a result, determining the pressure letter of the no monitoring point the Ye Qu vl1 Ingredient included in number；Short Time Fourier Transform is carried out to the pressure signal of the no monitoring point the Ye Qu vl1, is supervised by no leaf area The corresponding Short Time Fourier Transform of the pressure signal of measuring point vl1 is as a result, primarily determine swashing for the included ingredient of the pressure signal Encourage position sources；Wherein, ingredient included in the pressure signal of the no monitoring point the Ye Qu vl1 includes particular frequencies ingredient a and spy Different frequency content b；
Step 2: the time-domain diagram for obtaining the pressure signal of movable guide vane portal monitoring point gv1 is calculated by three-dimensional CFD, and right The pressure signal of the movable guide vane portal monitoring point gv1 carries out Fast Fourier Transform (FFT) and Short Time Fourier Transform, according to fast Fast Fourier transformation and Short Time Fourier Transform result determine in the pressure signal of the movable guide vane portal monitoring point gv1 Ingredient and its ingredient energized position source；Wherein, at subpackage included in the pressure signal of the guide vane portal monitoring point gv1 Include particular frequencies ingredient a, particular frequencies ingredient b, particular frequencies ingredient c and particular frequencies ingredient d；
Step 3: the time-domain diagram for obtaining the pressure signal of fixed guide vane portal monitoring point sv1 is calculated by three-dimensional CFD, and right The pressure signal of the fixed guide vane portal monitoring point sv1 carries out Fast Fourier Transform (FFT) and Short Time Fourier Transform, according to fast Fast Fourier transformation and Short Time Fourier Transform result determine in the pressure signal of the fixed guide vane portal monitoring point sv1 Ingredient and its ingredient energized position source；Wherein, included in the pressure signal of the fixed guide vane portal monitoring point sv1 at Divide includes particular frequencies ingredient a, particular frequencies ingredient b, particular frequencies ingredient c and particular frequencies ingredient d；
Step 4: the time-domain diagram for obtaining the pressure signal of spiral case monitoring point sp1 is calculated by three-dimensional CFD, and to the spiral case The pressure signal of monitoring point sp1 carries out Fast Fourier Transform (FFT) and Short Time Fourier Transform, according to Fast Fourier Transform (FFT) and short When Fourier transformation result determine the energized position of the ingredient and its ingredient that include in the pressure signal of the spiral case monitoring point sp1 Source；Wherein, ingredient included in the pressure signal of the fixed guide vane portal monitoring point sv1 include particular frequencies ingredient a, it is special Frequency content b, particular frequencies ingredient c and particular frequencies ingredient d；
Step 5: the time-domain diagram for obtaining the pressure signal of runner portal monitoring point rn1 is calculated by three-dimensional CFD, and to described The pressure signal of runner portal monitoring point rn1 carries out Fast Fourier Transform (FFT) and Short Time Fourier Transform, according to fast Fourier Transformation and Short Time Fourier Transform result determine the ingredient for including in the pressure signal of the runner portal monitoring point rn1 and its at The energized position source divided；Wherein, ingredient included in the pressure signal of the runner portal monitoring point rn1 include particular frequencies at Divide a and particular frequencies ingredient b；
Step 6: the time-domain diagram for obtaining the pressure signal of draft tube import measuring point dt1 is calculated by three-dimensional CFD, and to described The pressure signal of draft tube import measuring point dt1 carries out Fast Fourier Transform (FFT) and Short Time Fourier Transform, according to fast Fourier Transformation and Short Time Fourier Transform result determine the ingredient for including in the pressure signal of the draft tube import measuring point dt1 and its at The energized position source divided；Wherein, ingredient included in the pressure signal of the draft tube import measuring point dt1 include particular frequencies at Divide a, particular frequencies ingredient b, particular frequencies ingredient c and particular frequencies ingredient d；
Step 7: the time-domain diagram for obtaining the pressure signal of draft tube right cone section measuring point dt5 is calculated by three-dimensional CFD, and to institute The pressure signal for stating draft tube right cone section measuring point dt5 carries out Fast Fourier Transform (FFT) and Short Time Fourier Transform, according to quick Fu In leaf transformation and Short Time Fourier Transform result determine the ingredient for including in the pressure signal of the draft tube right cone section measuring point dt5 And its energized position source of ingredient；Wherein, ingredient included in the pressure signal of the draft tube right cone section measuring point dt5 includes spy Different frequency content a, particular frequencies ingredient b, particular frequencies ingredient c and particular frequencies ingredient d；
Step 8: the time-domain diagram for obtaining the pressure signal of the curved elbow section measuring point dt9 of draft tube is calculated by three-dimensional CFD, and to institute The pressure signal for stating the curved elbow section measuring point dt9 of draft tube carries out Fast Fourier Transform (FFT) and Short Time Fourier Transform, according to quick Fu In leaf transformation and Short Time Fourier Transform result determine the ingredient for including in the pressure signal of the curved elbow section measuring point dt9 of the draft tube And its energized position source of ingredient；Wherein, ingredient included in the pressure signal of the curved elbow section measuring point dt9 of the draft tube includes spy Different frequency content a, particular frequencies ingredient b, particular frequencies ingredient c and particular frequencies ingredient d.
The invention has the advantages that:
Pump turbine Dynamic Characteristics Analysis Method proposed by the present invention for removal of load process is compared to traditional water Pump turbine analysis method, by three-dimensional flow field calculating and the unit rotor kinetics equation use in conjunction of pump turbine, effectively Analyze the water wheels dynamics under load rejection operating condition during the fluctuation of speed and pump turbine runner internal flow Feature can be obtained in the case of the removal of load fluctuation of speed in pump turbine by the way that pressure fluctuation measuring point is arranged inside runner The time-frequency characteristic of pressure fluctuation at each measuring point in portion, find cause removal of load process external characteristics unstable the fluctuating frequency of pressure at Point, and pass through the vorticity and streamline distributions on stream interface among different moments runner area, it is established that particular pressure ripple frequency Inner link between ingredient and flow field structure.
Detailed description of the invention
Fig. 1 is that unit runner revolving speed calculates algorithm flow chart.
Fig. 2 is tail water overpressure monitoring point distribution schematic diagram.
Fig. 3 is movable guide vane intermediate altitude applanation monitoring point distribution schematic diagram.
Fig. 4 is three different height applanation monitoring point distribution schematic diagrams of movable guide vane.
Fig. 5 is the FFT spectrum figure of measuring point vl1 pressure signal.
Fig. 6 is the STFT spectrogram of measuring point vl1 pressure signal.
Fig. 7 is the FFT spectrum figure of measuring point gv1 pressure signal.
Fig. 8 is the STFT spectrogram of measuring point gv1 pressure signal.
Fig. 9 is the FFT spectrum figure of measuring point sv1 pressure signal.
Figure 10 is the STFT spectrogram of measuring point sv1 pressure signal.
Figure 11 is the FFT spectrum figure of measuring point sc1 pressure signal.
Figure 12 is the STFT spectrogram of measuring point sc1 pressure signal.
Figure 13 is the FFT spectrum figure of measuring point rn1 pressure signal.
Figure 14 is the STFT spectrogram of measuring point rn1 pressure signal.
Figure 15 is the FFT spectrum figure of measuring point dt1 pressure signal.
Figure 16 is the STFT spectrogram of measuring point dt1 pressure signal.
Figure 17 is the FFT spectrum figure of measuring point dt5 pressure signal.
Figure 18 is the STFT spectrogram of measuring point dt5 pressure signal.
Figure 19 is the FFT spectrum figure of measuring point dt9 pressure signal.
Figure 20 is the STFT spectrogram of measuring point dt9 pressure signal.
Figure 21 is hydraulic turbine discharge change procedure figure.
Figure 22 is runner moment variations process.
Figure 23 is Q11-n11Combined characteristic figure.
Figure 24 is T11-n11Combined characteristic figure.
Figure 25 is t=0.20 seconds moment fixed guide vanes, movable guide vane and runner intermediate altitude stream interface at each selected moment Vorticity Distribution cloud atlas.
Figure 26 is t=3.82 seconds moment fixed guide vanes, movable guide vane and runner intermediate altitude stream interface at each selected moment Vorticity Distribution cloud atlas.
Figure 27 is t=5.10 seconds moment fixed guide vanes, movable guide vane and runner intermediate altitude stream interface at each selected moment Vorticity Distribution cloud atlas.
Figure 28 is t=6.44 seconds moment fixed guide vanes, movable guide vane and runner intermediate altitude stream interface at each selected moment Vorticity Distribution cloud atlas.
Figure 29 is t=7.00 seconds moment fixed guide vanes, movable guide vane and runner intermediate altitude stream interface at each selected moment Vorticity Distribution cloud atlas.
Figure 30 is t=9.40 seconds moment fixed guide vanes, movable guide vane and runner intermediate altitude stream interface at each selected moment Vorticity Distribution cloud atlas.
Figure 31 is each moment draft tube streamline distribution figure in t=0.02 seconds moment Transients of Load Rejection.
Figure 32 is each moment draft tube streamline distribution figure in t=3.94 seconds moment Transients of Load Rejection.
Figure 33 is each moment draft tube streamline distribution figure in t=6.02 seconds moment Transients of Load Rejection.
Figure 34 is each moment draft tube streamline distribution figure in t=7.48 seconds moment Transients of Load Rejection.
Specific embodiment
The present invention will be further described combined with specific embodiments below, but the present invention should not be limited by the examples.
Embodiment 1:
A kind of Dynamic Characteristics Analysis Method for pump turbine in removal of load process, the Dynamic Characteristics Analysis Method Include:
Step 1: water pump water is established by zoning of spiral case, fixed guide vane, movable guide vane, runner and draft tube respectively The Three dimensional transient computation model of turbine, using computational domain of the Meshing Method to the Three dimensional transient computation model carry out from It dissipates, and is verified by grid independence and determine grid node number；
Step 2: respectively to spiral case, fixed guide vane, movable guide vane, runner and the draft tube in Three dimensional transient computation model Boundary condition, calculating and setting and the turbulence model of five zonings are configured；
Step 3: calculating runner revolving speed according to rotor dynamics, and removal of load is carried out based on the runner revolving speed Transient calculates；
Step 4: pressure-measuring-point is arranged in the full basin of the pump turbine, passes through the time domain specification of pressure-measuring-point The pressure fluctuation characteristics for obtaining pump turbine removal of load process, using the pressure fluctuation characteristics of acquisition to pump turbine The dynamic characteristic parameter of removal of load process is analyzed, and is determined in the pressure signal of the pressure-measuring-point comprising particular frequencies ingredient A, particular frequencies ingredient b, particular frequencies ingredient or particular frequencies ingredient d, and primarily determine that pressure signal includes each ingredient Energized position source；
Step 5: pass through the dynamic characteristic parameter of pump turbine removal of load process and pump turbine removal of load process The synthesis external characteristics of flow and runner torque external characteristics and removal of load process determines the particular frequencies ingredient a, particular frequencies The inducement of ingredient b, particular frequencies ingredient c and particular frequencies ingredient d；
Step 6: pump turbine pressure signal spectrogram during the Vorticity Distribution and removal of load of pump turbine is utilized Fluidised form in vorticity evolution process and draft tube during pump turbine removal of load is analyzed, from vorticity evolution process and Particular frequencies ingredient a, particular frequencies ingredient b, particular frequencies ingredient c and particular frequencies ingredient are obtained in draft tube in terms of fluidised form two The concrete reason that d is generated, and then pump turbine is completed in the dynamic analysis of removal of load procedure.
Wherein, the setting up procedure of boundary condition, calculating and setting described in step 2 and turbulence model includes:
Step 1: respectively to spiral case, fixed guide vane, movable guide vane, runner and the draft tube in Three dimensional transient computation model The boundary condition of five zonings is configured, and is specifically configured to: spiral case inlet section boundary condition setting is Pressure- inlet；The boundary condition of draft tube outlet section is set as Pressure-outlet；Runner region uses sliding mesh model；Snail Shell outlet and fixed guide vane import, fixed guide vane outlet and movable guide vane import, movable guide vane outlet and runner import, runner go out Mouth and draft tube import are set as 4 pairs of interface boundary conditions；Field at the beginning of calculating stable state using the parameter of initial operating point, makees The initialization condition calculated for subsequent transient state；
Step 2: being configured to turbulence model, be specifically configured to: turbulence model uses RNGk- ε model, and uses SIMPLEC algorithm carries out numerical solution to Fluid Control Equation；
Step 3: carrying out calculating and setting, be specifically configured to: the convergence residual error of all parameters is disposed as in numerical value calculating 1.0e-5；In unsteady state circumstance, for 0.0017 second, the greatest iteration step number of each time step was set as the time step used 30 steps.
The computational algorithm of runner revolving speed described in step 3 is as shown in Figure 1, its calculating process includes:
According to rotor dynamics, rotor angular momentum equilibrium equation is obtained, the rotor angular momentum equilibrium equation is as follows:
Wherein, resultant moment suffered by M --- rotor (Nm)；
J --- rotor moment of inertia (kgm2)；
ω --- rotor velocity (rad/s)；
T --- the time (s)；
By the rotor angular momentum equilibrium equation carry out it is discrete, with C language will be discrete after equation form be compiled into Fluent User-Defined Functions load compiling, to control the rotation of runner, and in each time step in Fluent It is called in iterative process, exports the revolving speed and torque parameter of each step.Transients of Load Rejection calculate it is accurate whether it is most heavy The judgment basis wanted is to simulate the generating unit speed come, utilizes the runner that runner revolving speed calculation method simulates described in the present embodiment The error of revolving speed and test value remains within 5%, improves the accuracy of runner revolving speed simulation, and then improve removal of load The accuracy of transient process calculation.
The position of pressure-measuring-point described in step 4 included: in the plane of tandem cascade intermediate altitude, along up time Needle direction is respectively arranged spiral case measuring point SC-MP-1~4, fixed guide vane entrance measuring point sv-1~6, movable guide vane entrance measuring point gv-1 ~20, without leaf area measuring point vl-1~20, runner entrance measuring point rn-1~9: crossing movable guide vane in the plane of base ring height, edge Be respectively arranged fixed guide vane entrance measuring point sv-dn-1~6, movable guide vane entrance measuring point gv-dn-1~20, nothing clockwise Leaf area measuring point vl-dn-1~20, runner entrance measuring point rn-dn-1~9: movable guide vane is crossed close to cap height, along clockwise Direction is respectively arranged fixed guide vane entrance measuring point sv-up-1~6, movable guide vane entrance measuring point gv-up-1~20, without leaf area measuring point Vl-up-1~20, runner entrance measuring point rn-up-1~9: cross draft tube three different cross sections be respectively arranged monitoring point DT1~ 12。
The specific steps of the pressure fluctuation characteristics of pump turbine removal of load process are obtained described in step 4 are as follows:
Step 1: the time-domain diagram for obtaining the pressure signal without the monitoring point Ye Qu vl1 is calculated by three-dimensional CFD, and to the nothing The pressure signal of the monitoring point Ye Qu vl1 carries out Fast Fourier Transform (FFT), and it is corresponding to obtain the pressure signal without the monitoring point Ye Qu vl1 Fast Fourier Transform (FFT) is as a result, by the Fast Fourier Transform (FFT) as a result, determining the pressure letter of the no monitoring point the Ye Qu vl1 Ingredient included in number；Short Time Fourier Transform is carried out to the pressure signal of the no monitoring point the Ye Qu vl1, is supervised by no leaf area The corresponding Short Time Fourier Transform of the pressure signal of measuring point vl1 is as a result, primarily determine swashing for the included ingredient of the pressure signal Encourage position sources；Wherein, ingredient included in the pressure signal of the no monitoring point the Ye Qu vl1 includes particular frequencies ingredient a and spy Different frequency content b；
Step 2: the time-domain diagram for obtaining the pressure signal of movable guide vane portal monitoring point gv1 is calculated by three-dimensional CFD, and right The pressure signal of the movable guide vane portal monitoring point gv1 carries out Fast Fourier Transform (FFT) and Short Time Fourier Transform, according to fast Fast Fourier transformation and Short Time Fourier Transform result determine in the pressure signal of the movable guide vane portal monitoring point gv1 Ingredient and its ingredient energized position source；Wherein, at subpackage included in the pressure signal of the guide vane portal monitoring point gv1 Include particular frequencies ingredient a, particular frequencies ingredient b, particular frequencies ingredient c and particular frequencies ingredient d；
Step 3: the time-domain diagram for obtaining the pressure signal of fixed guide vane portal monitoring point sv1 is calculated by three-dimensional CFD, and right The pressure signal of the fixed guide vane portal monitoring point sv1 carries out Fast Fourier Transform (FFT) and Short Time Fourier Transform, according to fast Fast Fourier transformation and Short Time Fourier Transform result determine in the pressure signal of the fixed guide vane portal monitoring point sv1 Ingredient and its ingredient energized position source；Wherein, included in the pressure signal of the fixed guide vane portal monitoring point sv1 at Divide includes particular frequencies ingredient a, particular frequencies ingredient b, particular frequencies ingredient c and particular frequencies ingredient d；
Step 4: the time-domain diagram for obtaining the pressure signal of spiral case monitoring point sp1 is calculated by three-dimensional CFD, and to the spiral case The pressure signal of monitoring point sp1 carries out Fast Fourier Transform (FFT) and Short Time Fourier Transform, according to Fast Fourier Transform (FFT) and short When Fourier transformation result determine the energized position of the ingredient and its ingredient that include in the pressure signal of the spiral case monitoring point sp1 Source；Wherein, ingredient included in the pressure signal of the fixed guide vane portal monitoring point sv1 include particular frequencies ingredient a, it is special Frequency content b, particular frequencies ingredient c and particular frequencies ingredient d；
Step 5: the time-domain diagram for obtaining the pressure signal of runner portal monitoring point rn1 is calculated by three-dimensional CFD, and to described The pressure signal of runner portal monitoring point rn1 carries out Fast Fourier Transform (FFT) and Short Time Fourier Transform, according to fast Fourier Transformation and Short Time Fourier Transform result determine the ingredient for including in the pressure signal of the runner portal monitoring point rn1 and its at The energized position source divided；Wherein, ingredient included in the pressure signal of the runner portal monitoring point rn1 include particular frequencies at Divide a and particular frequencies ingredient b；
Step 6: the time-domain diagram for obtaining the pressure signal of draft tube import measuring point dt1 is calculated by three-dimensional CFD, and to described The pressure signal of draft tube import measuring point dt1 carries out Fast Fourier Transform (FFT) and Short Time Fourier Transform, according to fast Fourier Transformation and Short Time Fourier Transform result determine the ingredient for including in the pressure signal of the draft tube import measuring point dt1 and its at The energized position source divided；Wherein, ingredient included in the pressure signal of the draft tube import measuring point dt1 include particular frequencies at Divide a, particular frequencies ingredient b, particular frequencies ingredient c and particular frequencies ingredient d；
Step 7: the time-domain diagram for obtaining the pressure signal of draft tube right cone section measuring point dt5 is calculated by three-dimensional CFD, and to institute The pressure signal for stating draft tube right cone section measuring point dt5 carries out Fast Fourier Transform (FFT) and Short Time Fourier Transform, according to quick Fu In leaf transformation and Short Time Fourier Transform result determine the ingredient for including in the pressure signal of the draft tube right cone section measuring point dt5 And its energized position source of ingredient；Wherein, ingredient included in the pressure signal of the draft tube right cone section measuring point dt5 includes spy Different frequency content a, particular frequencies ingredient b, particular frequencies ingredient c and particular frequencies ingredient d；
Step 8: the time-domain diagram for obtaining the pressure signal of the curved elbow section measuring point dt9 of draft tube is calculated by three-dimensional CFD, and to institute The pressure signal for stating the curved elbow section measuring point dt9 of draft tube carries out Fast Fourier Transform (FFT) and Short Time Fourier Transform, according to quick Fu In leaf transformation and Short Time Fourier Transform result determine the ingredient for including in the pressure signal of the curved elbow section measuring point dt9 of the draft tube And its energized position source of ingredient；Wherein, ingredient included in the pressure signal of the curved elbow section measuring point dt9 of the draft tube includes spy Different frequency content a, particular frequencies ingredient b, particular frequencies ingredient c and particular frequencies ingredient d.
To the no monitoring point Ye Qu vl1, movable guide vane portal monitoring point gv1, fixed guide vane portal monitoring point sv1, spiral case prison Measuring point sp1, runner portal monitoring point rn1, draft tube import measuring point dt1, draft tube right cone section measuring point dt5 and the curved elbow section of draft tube The pressure signal time frequency analysis of measuring point dt9 specifically:
The pressure signal time frequency analysis of the no monitoring point Ye Qu: the pressure signal without the monitoring point Ye Qu vl1 of acquisition is calculated Time-domain diagram carries out it Fast Fourier Transform (FFT) (FFT) to determine its frequency content, the Fast Fourier Transform (FFT) result As shown in figure 5, can be determined according to Fast Fourier Transform (FFT) result: in the pressure signal of the no monitoring point Ye Qu comprising 56~ 73Hz, 113~148Hz, the higher higher frequency band of 182~216Hz, tri- amplitudes and 0~50Hz a series of amplitude low frequencies Ingredient.Since removal of load process transfer frequency is 6.25~8.125Hz (f0~1.3f0), it is possible to determine that three amplitudes are higher Higher frequency band is approximately corresponding to 9 times, 18 times and 27 times respectively and turns frequency, shows the higher higher frequency band of these three amplitudes accordingly It is as caused by the stator-rotor interaction between runner and stationary parts.In order to determine the one of 0~50Hz of stator-rotor interaction effect and analysis The source of serial amplitude low-frequency component carries out Short Time Fourier Transform (STFT) to the pressure signal of vl1 measuring point, as a result as schemed Shown in 5.As seen from the figure, there are apparent stator-rotor interaction effects in the pressure signal, show as 9 times, 18 times and 27 times and turn frequency three Frequency band, it is corresponding with the result of fft analysis.But also there are three and 9 times, the 18 times and 27 times frequencies that turn frequency waveform opposite Rate band.In addition, about within 4~7 second period, in STFT spectrogram (Fig. 6) there is with 0 in FFT spectrum figure (Fig. 5)~ A series of corresponding amplitude frequency content a and b of amplitude low-frequency components of 50Hz, runner Hydraulic Moment is zero at this time, is reached Near maximum runaway speed.Thereby determine that the influence of the external characteristics within 4~7 second period, and determination is flowed out of time period Field carries out the source that incision analysis causes a series of continuous low-frequency component of amplitude of the 0~50Hz.
The pressure signal time frequency analysis of movable guide vane portal monitoring point: the movable guide vane portal monitoring point gv1 of acquisition is calculated Pressure signal time-domain diagram, in order to reach the mesh for carrying out time frequency analysis to the pressure signal of movable guide vane portal monitoring point gv1 , referring to the process of the pressure signal time frequency analysis of the no monitoring point Ye Qu vl1, quick Fu is carried out to the pressure signal of measuring point gv1 In leaf transformation (FFT) and Short Time Fourier Transform (STFT).The Fast Fourier Transform (FFT) (FFT) and Short Time Fourier Transform (STFT) result is as shown in Figure 7 and Figure 8, and FFT result is turning frequency it was determined that in pressure signal at movable guide vane entrance gv1 Multiple frequency ingredient in terms of, only 9 frequency multiplication ingredients (56~73Hz) amplitude of pulsing is higher, but the pulsation width relative to no leaf area Be worth it is much lower, can determine this is because integral multiple turn frequency pressure fluctuation ingredient be as caused by the stator-rotor interaction of runner, So closer apart from runner, influence is bigger, and vice versa.There is also similar with no leaf area measuring point vl1 in same FFT result A series of continuous low-frequency component of amplitude of 0~50Hz, but the maximum amplitude of its pulsation is high by one compared at no leaf area measuring point vl1 A bit, it is possible thereby to determine, the amplitude low-frequency component of this 0~50Hz a series of is not as caused by stator-rotor interaction.According to Fig. 8 institute The STFT result shown is it was determined that STFT is basic about the spectrum distribution and fft analysis result of runner multiple frequency out as the result is shown Unanimously, but in the STFT spectrogram of gv1 there is no with 9 times, the 18 times and 27 times frequency bands that turn frequency waveform opposite, this is further Illustrate strong influence of the stator-rotor interaction effect to no leaf area.About 0~50Hz in 4~7 second period is appeared in simultaneously A series of special low-frequency component of amplitude pulsation is also strong not as at no leaf area, it is possible thereby to determine the one of 0~50Hz The exciting source of the special low-frequency component of serial amplitude pulsation should be in no leaf area.In addition, about within 7~7.5 second period There is also the amplitude pulsation frequencies that one group is about 50~250Hz continuous high frequency in the pressure signal of movable guide vane entrance measuring point gv1 The amplitude ripple frequency ingredient d for the continuous high frequency that rate ingredient c and one group are about 100~250Hz, and this two groups of frequency contents exist It in no leaf area and is not present, infers that its excitaton source should the area Bu Wuye accordingly.
The pressure signal time frequency analysis of fixed guide vane portal monitoring point: the fixed guide vane portal monitoring point sv1 of acquisition is calculated Pressure signal time-domain diagram, analogy purpose identical with movable guide vane regional analysis and method, to the pressure signal of measuring point sv1 Carry out Fast Fourier Transform (FFT) (FFT) and Short Time Fourier Transform (STFT).It is as shown in Figure 9 by FFT result, it can be deduced that fixed Guide vane entrance, there's almost no in the pressure signal at measuring point sv1 the blade passing frequency as caused by runner stator-rotor interaction and its Harmonic frequency causes the stator-rotor interaction effect of runner almost to propagate not this is because fixed guide vane region distance runner is remote enough Come over.But a series of amplitude of the 0~50Hz similar with no leaf area measuring point vl1 and movable guide vane region measuring point gv1 are continuous Low-frequency component still has, and maximum pulsation amplitude is higher compared with vl1 and gv1 measuring point, from tri- measuring point pressures of vl1, gv1 and sv1 The gradually raised variation relation of the maximum pulsation amplitude of the continuous low frequency of 0~50Hz of power pulsation, which can tentatively infer, to be obtained, this 0~ The exciting source of the continuous low frequency of 50Hz there are orientation.By STFT result (Figure 10) it can be concluded that, from no farther away fixation in leaf area Turn to turn to be eager to excel frequently compared with 9 times frequently for 18 times caused by the stator-rotor interaction of guide vane region.Existing amplitude is higher between 4~7 seconds The continuous Frequency ingredient a and b of about 5~50Hz is being reduced gradually compared to vl1 and gv1 measuring point, this further illustrates 5~ The vibration source of the continuous low frequency of 50Hz is closer to no leaf area.And it is present in the higher about 50~250Hz of the amplitude between 7~7.5 seconds Continuous high frequency ingredient c it is stronger compared with fixed guide vane region.From vl1 to sv1, measuring point is rising this frequency content gradually from scratch High variation illustrates that the vibration source of the continuous high frequency ingredient of the higher about 50~250Hz of existing amplitude between 7~7.5 seconds more leans on Nearly fixed guide vane region.There is also the frequency content d of high-frequency amplitude in same fixed guide vane region.
The pressure signal time frequency analysis of spiral case monitoring point: the time domain of the pressure signal of the spiral case monitoring point sp1 of acquisition is calculated Figure, and the pressure signal of measuring point sp1 carries out Fast Fourier Transform (FFT) (FFT) and Short Time Fourier Transform (STFT)；Its FFT and STFT result difference is as is illustrated by figs. 11 and 12.By FFT and STFT result can determine the pressure signal situation of measuring point sp1 with The result that fixed guide vane regional analysis goes out is almost the same, only not same, i.e., by STFT result (Figure 12) it was determined that fixed The entrance of guide vane region sv1 measuring point or the time of the continuous high frequency ingredient d in the higher about 100~250Hz of amplitude will be earlier than Or it is longer than 8.5~10 second period, this explanation causes the vibration source of the continuous high frequency ingredient of the higher about 100~250Hz of amplitude In the region closer apart from fixed guide vane.Between 4~7 seconds the continuous low frequency a of the higher about 5~50Hz of existing amplitude and B almost vanishes from sight, and can determine further according to analysis before: the exciting source of these low-frequency components is near no leaf area.
The pressure signal time frequency analysis of runner portal monitoring point: the pressure letter of the runner portal monitoring point rn1 of acquisition is calculated Number time-domain diagram FFT is carried out to it in order to which the frequency content pulsed to runner inlet pressure is analyzed, as a result such as Figure 13 institute Show.It is identical as no leaf area, exist in runner inlet pressure signals three frequencies as caused by runner stator-rotor interaction be about 56~ The pulsation amplitude of the higher higher frequency band of 73Hz, 125~150Hz, 200~210Hz amplitude and an about 0~50Hz are high Continuous Frequency band, but their pulsation amplitude will be high compared with measuring point in no leaf area.And shown according to Figure 12, in runner Any frequency values within the scope of the 0~250Hz that can determine out existing at entrance measuring point compared in the hydraulic turbine other are each The pulsation amplitude of the corresponding frequencies at place is generally much higher, this is related with removal of load process runner entrance Special complex flowing.And It is essentially identical for the result (Figure 14) of STFT analysis and the time-frequency characteristic distribution of no leaf area measuring point pressure, and and fft analysis Result it is the same, any frequency within the scope of 0~250Hz that can be distinguished existing for the runner entrance measuring point place It is worth generally much higher compared with the pulsation amplitude of other corresponding frequencies everywhere in the hydraulic turbine.
The pressure signal time frequency analysis of draft tube import: the pressure signal of the draft tube import measuring point dt1 of acquisition is calculated Time-domain diagram carries out FFT to the pressure signal of measuring point dt1 in order to which the time-frequency characteristic pulsed to draft tube inlet pressure is analyzed And STFT, as a result as shown in Figure 15 and Figure 16.Compared with no leaf area, include in the pressure signal at draft tube import measuring point dt1 It is about 56~73Hz, 113~146Hz, the 168~212Hz tri- slightly higher frequencies of amplitude of pulsing as caused by runner stator-rotor interaction Band, but its amplitude of pulsing is low compared with no leaf area, and this illustrates that outlet of rotary wheel flowing is much better compared with runner inlet flow situation.Equally Also the higher continuous low frequency a and b of amplitude containing one group of 0~50Hz, pulsation amplitude is also lower compared with no leaf area, illustrates 0 The vibration source of the continuous low frequency of~50Hz is slightly distal to no leaf area apart from draft tube import.And unlike no leaf area, draft tube import There is the 50~250Hz similar with spiral case region, fixed guide vane region and movable guide vane region within 6.5~8.5 second period The higher continuous high frequency c and d of pulsation amplitude, only slightly a little offsets, this explanation are removed on existing time and frequency range Outside without leaf area, there is the vibration source for the higher continuous high frequency of pulsation amplitude for causing 50~250Hz in upstream and downstream two sides.And It is same that 9 times, 18 times and 27 times in 6.5~8.5 second period pulsation amplitudes for turning three frequency bands of frequency will be apparently higher than no leaf area The situation of period, this is because the result of the continuous high frequency coupling of the stator-rotor interaction of draft tube entrance and 50~250Hz. Meanwhile draft tube import also slight presence and no leaf area similar two and the 18 times and 27 times frequencies that turn frequency waveform opposite Band, fluctuation intensity are weaker compared with no leaf area, can determine accordingly: these frequency bands opposite with leaf frequency and its harmonic wave forms Certainly related with runner stator-rotor interaction.
The pressure signal time frequency analysis of draft tube right cone section monitoring point: calculate the draft tube right cone section measuring point dt5's of acquisition The time-domain diagram of pressure signal, analogy draft tube import measuring point carry out FFT and STFT, gained FFT to the pressure signal of measuring point dt5 It is as shown in Figure 17 and Figure 18 with STFT result.From the figure, it can be seen that since dt5 ratio dt1 is farther apart from runner, so by sound Interference effect is smaller, shows as 18 times and 9 times and turns two weaker frequency bands of fluctuation intensity of frequency.And existing 0 in 4~7 seconds~ The fluctuation intensity of 50Hz low-frequency component a and b also constantly weaken with the increase with a distance from no leaf area.But near 7.5 seconds Existing c frequency content and there are d frequency content pulsation amplitude intensity to be enhanced compared with draft tube import dt1 in 8.5~10 seconds, And there are to be later than dt1 on the time.In addition, with spiral case region sp1, fixed guide vane region sv1, movable guide vane region gv1, nothing Leaf area vl1 and draft tube import dt1 are similar.
The pressure signal time frequency analysis of draft tube curved elbow section monitoring point: calculate the curved elbow section measuring point dt9's of draft tube of acquisition The time-domain diagram of pressure signal carries out FFT and STFT to the pressure signal of measuring point dt5, as a result as illustrated in figures 19 and 20.According to knot Fruit can determine that the analysis judgement of the curved elbow section measuring point dt9 of draft tube and draft tube right cone section measuring point dt5 are most of identical, only right In the high frequency band within the scope of 50~250Hz there are larger difference, close to draft tube downstream curved elbow section measuring point dt9 at 7~8 seconds and Continuous high frequency frequency content c and d show two (more other 7 measuring points) amplitude become apparent in 8~10 second period Ripple frequency band, and 0~250Hz cline frequency band in 8~10 seconds in the continuous high frequency band and 7~8 seconds of 50~250Hz Form is more similar.
Dynamic characteristic parameter described in step 5 includes flow and runner torque external characteristics and comprehensive external characteristics；
For flow and runner torque external characteristics: according to the feature distribution of pressure fluctuation time-frequency characteristic to removal of load process water The process that the flow (Figure 21) and runner torque (Figure 22) of pump turbine change over time is analyzed.As seen from the figure, in pressure Pulsation occurred in 4~6 seconds periods of the pulsation higher continuous low-frequency band a of amplitude, the flow and runner torque of pump turbine There is apparent pulsation in external characteristics.What this pulsatile characteristics occurred in analysis flow and runner torque from external characteristics is due to this Period (4~6 seconds) interior runner torque passes right through near zero point, and runner revolving speed is also universal higher in time period.In runner During torque changes from positive value to negative value, pump turbine is converted from hydraulic turbine accelerator to braking process, in runner Water flow suffered by the retardation of runner suddenly become impetus, during the change working of this mutability, examine Water flow is considered with certain inertia, thus the water flow in Turbine Flow Passage will necessarily generate very strong impact of water hammer oscillation Effect, while the head of the hydraulic turbine being caused to reach removal of load process peak value.With 6.5~7 seconds or so in pressure fluctuation time frequency analysis The higher cline frequency band b of amplitude of pulsing is corresponding, and discharge characteristic is shown, in 6.5~7 seconds or so pump turbine flows by just Value becomes negative value, and pump turbine enters pump condition of turning one's coat by hydraulic turbine damped condition, and pump turbine undergoes removal of load process In second mutability change working process.The water flow in draft tube downstream is reversely flow backwards suddenly at this time, to pump turbine Larger reverse impact effect is formed, while the head of pump turbine being made to drop sharply to minimum.In removal of load process First 0.8 second, due to quick closedown guide vane, so that flow and water flow efficiently control the pushing torque rapid decrease of runner The rising of generating unit speed, it is also smaller in pressure fluctuations in former seconds of removal of load process.
For comprehensive external characteristics: specific discharge Q11, unit speed n11With specific torque T11Equal unit parameters can be comprehensively anti- The overall characteristic index of pump turbine operation conditions is reflected, for the evaluation removal of load process pump turbine of all-dimensional multi-angle Operation conditions, the Q of numerical prediction11-n11And T11-n11Combined characteristic as shown in figure 23 and figure 24, as seen from the figure in T11 Equal to zero and Q11Equal to zero, the two are by hydraulic turbine condition to damped condition again to the Near The Critical Point for pump condition conversion of turning one's coat, water The Q of pump turbine11、n11And T11Recurrent fluctuations in equal overall characteristics parameter running track general trend, simultaneous are violent Low amplitude high frequency pulsation, pump turbine is in the critical point luck for undergoing the two change workings during being indicated above removal of load Row situation is extremely unstable.This is more comprehensively further illustrated from the angle of comprehensive external characteristics cause removal of load during water pump There is a (about at 4.5~6 seconds) in the pressure fluctuation signal of the hydraulic turbine and two pulsation amplitudes of b (about at 6.5~7.5 seconds) are higher The pressure fluctuation time-frequency distributions feature of cline frequency band.
Vorticity evolution process described in step 6 is analyzed as follows: by the vorticity point of removal of load process pump turbine flow field Cloth (Figure 25-Figure 30) can determine: at first 3.8 seconds, pump turbine flow field fluidised form was smooth, only in fixed guide vane entrance region Weaker whirlpool is spent before having inside domain and runner on a small quantity, the pressure and external characteristics of pump turbine are also without too big wave in time period It is dynamic；Removal of load process proceeds to 3.82 seconds, runner two entrance edge of blade without the height near leaf area due to runner region Speed shearing forms two circumferentially tangential whirlpools；It is constantly increased without leaf area flow velocity later, so that without fast between leaf area and runner Degree gradient constantly increases, to also sequentially form near other each vane inlets under the high speed shear effect of runner import Some tangential distribution whirlpools, and as the intensity in these tangential distribution whirlpools of the propulsion of time constantly increases, until load process into Row was by 5.1 seconds or so, and runner Hydraulic Moment is zero at this time, and runner revolving speed reaches maximum runaway speed, the development of these tangential distribution whirlpools To being almost full with entirely without leaf area, later as no leaf area flow velocity continues to increase, the intensity in these whirlpools also constantly enhances；And works as and get rid of Load process proceeds to 6.44 seconds or so, is now near zero delivery operating condition, since pump turbine is gradually by hydraulic turbine work Condition enters pump condition of turning one's coat, and in this way under the percussion of the reversed incoming flow of downstream draft tube, the whirlpool in no leaf area is with reversed next Stream progresses into tandem cascade, so that the Vorticity Distribution without leaf area gradually decreases, until reaching 7 seconds or so, water pump water wheels Machine reverse flow reaches maximum value, and the distribution whirlpool in no leaf area is thoroughly gone out into tandem cascade；Later with pump turbine Reverse flow gradually decreases, and the flow velocity in no leaf area is gradually lowered, but under the shear action in runner region, in runner and without leaf Restart to form 9 tangential distribution whirlpools at the interface in area, these distribution whirlpools are continued to develop with time stepping method, reach 9.4 Second or so, it is now placed in reversed zero delivery operating condition and is nearby gradually linked to be an annular entirety in this 9 tangential distribution whirlpools, in runner Hydraulic turbine upstream and downstream is thoroughly separated at the interface in no leaf area.Just because of after removal of load from hydraulic turbine condition to braking Operating condition arrives again turn one's coat pump condition during, there is above-mentioned vorticity change procedure in pump turbine flow field, so It will lead to, height representated by a frequency content occur in the pressure fluctuation spectrogram of pump turbine near the zero moment operating point The continuous low frequency pulsating of amplitude, and recurrent fluctuations in general trend is shown in comprehensive external characteristics, simultaneous are violent The dynamic instability characteristic of low amplitude high frequency pulsation；The pressure fluctuation frequency of pump turbine near maximum reverse flow rate working conditions point High frequency high-amplitude ingredient representated by the c frequency content occurred in spectrogram；In reverse flow close to water pump near zero delivery operating point Occurs the cline frequency band of d frequency content representative in the pressure fluctuation spectrogram of the hydraulic turbine.
The analytic process of fluidised form is as follows in draft tube described in step 6: so far can be determined: got rid of according to the analysis of front A frequency content in load process in pump turbine pressure signal spectrogram in 4.5~6 second period is by runner and without leaf High speed shear between area is caused by the tangential distribution whirlpool moved in the circumferential direction that no leaf area is formed about；6.5~7.5 seconds or so B frequency content band is by entering the reverse counterflow after pump condition of turning one's coat to caused by the moment impact effect of pump turbine；And Exist at other each measuring points of the upstream and downstream in no leaf area for the c frequency content after being present in about 7.5 seconds or so, and It is but not present in no leaf area, furthermore the Vorticity Distribution by no leaf area after 7.5 seconds and streamline distribution are it was determined that at this time without leaf Area's upstream and downstream, which is almost obstructed by the high speed circulation (" drip ring ") in no leaf area, breaks, and thereby determines that no leaf area upstream and downstream c frequency Ingredient is as caused by different vibration sources.By front vorticity analysis it is found that the c frequency content without each measuring point in the upstream Ye Qu be by Caused by the whirling motion for flowing to whirlpool and prospect spape in tandem cascade.And at measuring point dt1, dt5 and dt9 each for no downstream Ye Qu The exciting source of the c frequency content of pressure signal then needs to determine by analyzing draft tube fluidised form.According to removal of load transition Each moment draft tube streamline distribution (Figure 31-Figure 34) in the process, can determine: the whirling motion in preceding 6 seconds draft tubes is mainly concentrated In draft tube central area, and draft tube wall surface is then separated by one layer by the flowing of prewhirling that runner flows out, so being present in tail Influence of the whirling motion in centre of conduit region to each measuring point of dt1~dt9 against near wall is smaller.And after 6 seconds, pump turbine Into pump condition of turning one's coat, in time period the reverse reflux of draft tube right cone section central area and draft tube near wall region by Since high speed shear acts between the downward flowing of prewhirling of runner outflow, a series of whirlpools are formed in the near wall of right cone section, Period effects (such whirlpool is significantly away from dt1 as seen from the figure, is transmitted to dt5) is carried out to wall surface.And in curved elbow section, due to being centrifuged masterpiece With reverse reflux is flowed on the outside of curved elbow section, and is interacted with the forward flow surveyed in curved elbow, thus attached in curved elbow section A biggish whirlpool is closely formed, the whirlpool that this whirlpool and right cone section flow down forms periodical effect to curved elbow section wall surface jointly.Exactly Due to this special flowing in removal of load process draft tube, after resulting in just now pump turbine removal of load 7.5 seconds or so Occurs higher frequency representated by a c frequency content in draft tube in the pressure signal spectrogram of each measuring point of dt1~dt9 Band.
Analysis method of the present invention carries out the boundary condition setting of Transients of Load Rejection CFD calculating and calculates to set first It sets, detailed time-frequency characteristic has been carried out to the pressure fluctuation of component measuring points different in entire basin later and has been analyzed, has obtained four kinds Special frequency content a, b, c and d, and tentatively their excitation source position is analyzed.Later from the angle of external characteristics Give the inducement of particular frequencies ingredient.Finally the flow field in Transients of Load Rejection is analyzed, from vorticity and tail Two aspects of water pipe fluidised form give the concrete reason of particular frequencies ingredient formation.
Although the present invention has been disclosed in the preferred embodiment as above, it is not intended to limit the invention, any to be familiar with this The people of technology can do various changes and modification, therefore protection of the invention without departing from the spirit and scope of the present invention Range should subject to the definition of the claims.

Claims (5)

1. it is a kind of for pump turbine removal of load procedure Dynamic Characteristics Analysis Method, which is characterized in that it is described dynamic Step response analysis method includes:
Step 1: pump turbine is established using spiral case, fixed guide vane, movable guide vane, runner and draft tube as zoning respectively Three dimensional transient computation model, the computational domain of the Three dimensional transient computation model is carried out using Meshing Method it is discrete, and It is verified by grid independence and determines grid node number；
Step 2: respectively to the spiral case in Three dimensional transient computation model, fixed guide vane, movable guide vane, runner and draft tube five Boundary condition, calculating and setting and the turbulence model of zoning are configured；
Step 3: calculating runner revolving speed according to rotor dynamics, and progress removal of load, which is crossed, based on the runner revolving speed tides over Journey calculates；
Step 4: arranging pressure-measuring-point in the full basin of the pump turbine, is obtained by the time domain specification of pressure-measuring-point The pressure fluctuation characteristics of pump turbine removal of load process get rid of pump turbine using the pressure fluctuation characteristics of acquisition negative The dynamic characteristic parameter of lotus process is analyzed, and is determined in the pressure signal of the pressure-measuring-point comprising particular frequencies ingredient a, spy Different frequency content b, particular frequencies ingredient or particular frequencies ingredient d, and primarily determine that pressure signal includes the excitation of each ingredient Position sources；
Step 5: pass through the dynamic characteristic parameter of pump turbine removal of load process and the flow of pump turbine removal of load process The particular frequencies ingredient a, particular frequencies ingredient are determined with the synthesis external characteristics of runner torque external characteristics and removal of load process B, the inducement of particular frequencies ingredient c and particular frequencies ingredient d；
Step 6: using pump turbine pressure signal spectrogram during the Vorticity Distribution and removal of load of pump turbine to water Fluidised form is analyzed in vorticity evolution process and draft tube during pump turbine removal of load, from vorticity evolution process and tail water Particular frequencies ingredient a, particular frequencies ingredient b, particular frequencies ingredient c and particular frequencies ingredient d are obtained in managing in terms of fluidised form two to produce Raw concrete reason, and then pump turbine is completed in the dynamic analysis of removal of load procedure.
2. Dynamic Characteristics Analysis Method according to claim 1, which is characterized in that boundary condition described in step 2, calculating are set It sets and includes: with the setting up procedure of turbulence model
Step 1: respectively to the spiral case in Three dimensional transient computation model, fixed guide vane, movable guide vane, runner and draft tube five The boundary condition of zoning is configured, and is specifically configured to: spiral case inlet section boundary condition setting is Pressure- inlet；The boundary condition of draft tube outlet section is set as Pressure-outlet；Runner region uses sliding mesh model；Snail Shell outlet and fixed guide vane import, fixed guide vane outlet and movable guide vane import, movable guide vane outlet and runner import, runner go out Mouth and draft tube import are set as 4 pairs of interface boundary conditions；Field at the beginning of calculating stable state using the parameter of initial operating point, makees The initialization condition calculated for subsequent transient state；
Step 2: being configured to turbulence model, be specifically configured to: turbulence model uses RNGk- ε model, and uses SIMPLEC Algorithm carries out numerical solution to Fluid Control Equation；
Step 3: carrying out calculating and setting, be specifically configured to: the convergence residual error of all parameters is disposed as 1.0e- in numerical value calculating 5；In unsteady state circumstance, for the time step used for 0.0017 second, the greatest iteration step number of each time step was set as 30 steps.
3. Dynamic Characteristics Analysis Method according to claim 1, which is characterized in that the calculating of runner revolving speed described in step 3 Journey includes:
According to rotor dynamics, rotor angular momentum equilibrium equation is obtained, the rotor angular momentum equilibrium equation is as follows:
Wherein, resultant moment suffered by M --- rotor (Nm)；
J --- rotor moment of inertia (kgm2)；
ω --- rotor velocity (rad/s)；
T --- the time (s)；
By the rotor angular momentum equilibrium equation carry out it is discrete, with C language will be discrete after equation form be compiled into Fluent User-Defined Functions load compiling, to control the rotation of runner, and in each time step iteration mistake in Fluent It is called in journey, exports the revolving speed and torque parameter of each step.
4. Dynamic Characteristics Analysis Method according to claim 1, which is characterized in that the cloth set of pressure-measuring-point described in step 4 Set included: to be respectively arranged spiral case measuring point SC-MP-1~4 clockwise in the plane of tandem cascade intermediate altitude, consolidate Determine guide vane entrance measuring point sv-1~6, movable guide vane entrance measuring point gv-1~20, surveyed without leaf area measuring point vl-1~20, runner entrance Point rn-1~9: crossing movable guide vane in the plane of base ring height, is respectively arranged the survey of fixed guide vane entrance clockwise Point sv-dn-1~6, movable guide vane entrance measuring point gv-dn-1~20, without leaf area measuring point vl-dn-1~20, runner entrance measuring point Rn-dn-1~9: movable guide vane is crossed close to cap height, is respectively arranged fixed guide vane entrance measuring point sv- clockwise Up-1~6, movable guide vane entrance measuring point gv-up-1~20, without leaf area measuring point vl-up-1~20, runner entrance measuring point rn-up-1 ~9: three different cross sections for crossing draft tube are respectively arranged monitoring point DT1~12.
5. Dynamic Characteristics Analysis Method according to claim 3, which is characterized in that acquisition pump turbine described in step 4 is got rid of The specific steps of the pressure fluctuation characteristics of load process are as follows:
Step 1: the time-domain diagram for obtaining the pressure signal without the monitoring point Ye Qu vl1 is calculated by three-dimensional CFD, and to the no leaf area The pressure signal of monitoring point vl1 carries out Fast Fourier Transform (FFT), and it is corresponding quickly to obtain the pressure signal without the monitoring point Ye Qu vl1 Fourier transformation is as a result, by the Fast Fourier Transform (FFT) as a result, determining in the pressure signal of the no monitoring point the Ye Qu vl1 Included ingredient；Short Time Fourier Transform is carried out to the pressure signal of the no monitoring point the Ye Qu vl1, passes through no monitoring point Ye Qu The corresponding Short Time Fourier Transform of the pressure signal of vl1 is as a result, primarily determine the excitation position of the included ingredient of the pressure signal Set source；Wherein, ingredient included in the pressure signal of the no monitoring point the Ye Qu vl1 includes particular frequencies ingredient a and special frequency Rate ingredient b；
Step 2: the time-domain diagram for obtaining the pressure signal of movable guide vane portal monitoring point gv1 is calculated by three-dimensional CFD, and to described The pressure signal of movable guide vane portal monitoring point gv1 carries out Fast Fourier Transform (FFT) and Short Time Fourier Transform, according to quick Fu In leaf transformation and Short Time Fourier Transform result determine include in the pressure signal of the movable guide vane portal monitoring point gv1 at Point and its ingredient energized position source；Wherein, ingredient included in the pressure signal of the guide vane portal monitoring point gv1 includes spy Different frequency content a, particular frequencies ingredient b, particular frequencies ingredient c and particular frequencies ingredient d；
Step 3: the time-domain diagram for obtaining the pressure signal of fixed guide vane portal monitoring point sv1 is calculated by three-dimensional CFD, and to described The pressure signal of fixed guide vane portal monitoring point sv1 carries out Fast Fourier Transform (FFT) and Short Time Fourier Transform, according to quick Fu In leaf transformation and Short Time Fourier Transform result determine include in the pressure signal of the fixed guide vane portal monitoring point sv1 at Point and its ingredient energized position source；Wherein, at subpackage included in the pressure signal of the fixed guide vane portal monitoring point sv1 Include particular frequencies ingredient a, particular frequencies ingredient b, particular frequencies ingredient c and particular frequencies ingredient d；
Step 4: calculating the time-domain diagram for obtaining the pressure signal of spiral case monitoring point sp1 by three-dimensional CFD, and the spiral case is monitored The pressure signal of point sp1 carries out Fast Fourier Transform (FFT) and Short Time Fourier Transform, according to Fast Fourier Transform (FFT) and Fu in short-term In leaf transformation result determine the energized position source of the ingredient and its ingredient that include in the pressure signal of the spiral case monitoring point sp1； Wherein, ingredient included in the pressure signal of the fixed guide vane portal monitoring point sv1 includes particular frequencies ingredient a, special frequency Rate ingredient b, particular frequencies ingredient c and particular frequencies ingredient d；
Step 5: the time-domain diagram for obtaining the pressure signal of runner portal monitoring point rn1 is calculated by three-dimensional CFD, and to the runner The pressure signal of portal monitoring point rn1 carries out Fast Fourier Transform (FFT) and Short Time Fourier Transform, according to Fast Fourier Transform (FFT) The ingredient and its ingredient for including in the pressure signal of the runner portal monitoring point rn1 are determined with Short Time Fourier Transform result Energized position source；Wherein, ingredient included in the pressure signal of the runner portal monitoring point rn1 includes particular frequencies ingredient a With particular frequencies ingredient b；
Step 6: the time-domain diagram for obtaining the pressure signal of draft tube import measuring point dt1 is calculated by three-dimensional CFD, and to the tail water The pressure signal of pipe import measuring point dt1 carries out Fast Fourier Transform (FFT) and Short Time Fourier Transform, according to Fast Fourier Transform (FFT) The ingredient and its ingredient for including in the pressure signal of the draft tube import measuring point dt1 are determined with Short Time Fourier Transform result Energized position source；Wherein, ingredient included in the pressure signal of the draft tube import measuring point dt1 include particular frequencies ingredient a, Particular frequencies ingredient b, particular frequencies ingredient c and particular frequencies ingredient d；
Step 7: the time-domain diagram for obtaining the pressure signal of draft tube right cone section measuring point dt5 is calculated by three-dimensional CFD, and to the tail The pressure signal of water pipe right cone section measuring point dt5 carries out Fast Fourier Transform (FFT) and Short Time Fourier Transform, according to fast Fourier Transformation and Short Time Fourier Transform result determine the ingredient for including in the pressure signal of the draft tube right cone section measuring point dt5 and its The energized position source of ingredient；Wherein, ingredient included in the pressure signal of the draft tube right cone section measuring point dt5 includes special frequency Rate ingredient a, particular frequencies ingredient b, particular frequencies ingredient c and particular frequencies ingredient d；
Step 8: the time-domain diagram for obtaining the pressure signal of the curved elbow section measuring point dt9 of draft tube is calculated by three-dimensional CFD, and to the tail The pressure signal of the curved elbow section measuring point dt9 of water pipe carries out Fast Fourier Transform (FFT) and Short Time Fourier Transform, according to fast Fourier Transformation and Short Time Fourier Transform result determine the ingredient for including in the pressure signal of the curved elbow section measuring point dt9 of the draft tube and its The energized position source of ingredient；Wherein, ingredient included in the pressure signal of the curved elbow section measuring point dt9 of the draft tube includes special frequency Rate ingredient a, particular frequencies ingredient b, particular frequencies ingredient c and particular frequencies ingredient d.
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