CN-121978914-A - Guide vane optimization control method for hydraulic transition process of water pump turbine based on dynamic pressure pulsation simulation algorithm

CN121978914ACN 121978914 ACN121978914 ACN 121978914ACN-121978914-A

Abstract

The invention provides a guide vane optimization control method for a hydraulic transition process of a water pump turbine based on a dynamic pressure pulsation simulation algorithm, which comprises the steps of carrying out one-dimensional hydraulic transient simulation, obtaining a water impact mean value pressure change curve of a volute and a draft tube in the transition process, carrying out a full pressure pulsation test based on a water pump turbine model, establishing a pressure pulsation database, combining one-dimensional hydraulic transient simulation results with full pressure pulsation test data, constructing a coupling relation model between a guide vane closing track and a pressure pulsation response, quantitatively analyzing the influence of different guide vane closing rules on the pressure pulsation intensity, taking the pressure pulsation amplitude as an optimization target, and screening the comprehensive optimal guide vane closing rules of the water impact mean value pressure and the pressure pulsation amplitude based on the prediction result of the coupling relation model. According to the invention, the pressure pulsation amplitude is introduced as a core parameter to optimize the guide vane closing method, so that the actual stress state of the water pump turbine unit is truly reflected, and the system safety is improved.

Inventors

WANG QING
DU RONGXING

Assignees

东芝水电设备（杭州）有限公司

Dates

Publication Date: 20260505
Application Date: 20260106

Claims (8)

1. The guide vane optimization control method for the hydraulic transition process of the water pump turbine based on the dynamic pressure pulsation simulation algorithm is characterized by comprising the following steps: s1) constructing a one-dimensional hydraulic transient simulation calculation model Based on the unit operation condition, carrying out one-dimensional hydraulic transient simulation, acquiring a water impact mean pressure change curve of the volute and the draft tube in the transition process, and extracting relevant parameters of a guide vane closing track; s2) full pressure pulsation test data extraction Developing a full-pressure pulsation test based on a water pump turbine model, extracting data of unit rotating speed, unit flow and pressure pulsation amplitude under different guide vane opening degrees, covering a four-quadrant full-working condition range, and establishing a pressure pulsation database; s3) constructing a coupling relation model Fusing the one-dimensional hydraulic transient simulation result of the S1) and the full pressure pulsation test data of the S2), constructing a coupling relation model between a guide vane closing track and a pressure pulsation response, and quantitatively analyzing the influence of different guide vane closing rules on the pressure pulsation intensity; The coupling relation model builds a pressure pulsation fitting function through Interp interpolation, and input variables of the function at least comprise unit rotating speed, unit flow and guide vane opening; S4) optimization design of guide vane closing rule Taking the pressure pulsation amplitude minimization as an optimization target, and adopting a guide vane sectional closing mode of 'fast before slow'; And screening a comprehensive optimal guide vane closing rule for the water hammer mean pressure and the pressure pulsation amplitude based on the prediction result of the coupling relation model.
2. The method for optimally controlling the guide vane of the hydraulic transition process of the water pump turbine based on the dynamic pressure pulsation simulation algorithm according to claim 1, wherein in the step S1), when a one-dimensional hydraulic transient simulation calculation model is constructed, input parameters comprise an initial guide vane opening degree (GV 0), an initial rotating speed (n 0), an initial flow rate (Q0), a moment of inertia (GD 2 ), a guide vane preliminary closing rule, a simulation time step (deltat) and a working condition type.
3. The method for optimally controlling the guide vane in the hydraulic transition process of the water pump turbine based on the dynamic pressure pulsation simulation algorithm according to claim 1 or 2, wherein in the step S1), when a one-dimensional hydraulic transient simulation calculation model is constructed, the output result comprises the water hammer mean pressure Pmean (t) at each moment, the corresponding unit rotating speed n11 (t), the unit flow Q11 (t) and the guide vane opening GV (t).
4. The guide vane optimization control method for the hydraulic transition process of the water pump turbine based on the dynamic pressure pulsation simulation algorithm is characterized in that in the step S3), a pressure pulsation fitting function is constructed to be Ppulsation (t) =f (n 11 (t), Q11 (t) and GV (t)), wherein n11 (t) is a unit rotating speed and is related to the fundamental frequency of pressure pulsation, Q11 (t) is a unit flow and affects the amplitude of the pressure pulsation, GV (t) is a guide vane opening track, a function form is constructed by adopting a Interp interpolation method, and a specific function relation is determined according to model test data distribution.
5. The method for optimally controlling the guide vane of the hydraulic transition process of the water pump turbine based on the dynamic pressure pulsation simulation algorithm according to claim 4, wherein in the step S3), the formula for calculating the total dynamic water pressure is Ptotal (t) =Pmean (t) +Ppulsation (t), wherein Pmean (t) is the water hammer mean pressure obtained by a one-dimensional hydraulic transient simulation calculation model, and Ppulsation (t) is the pressure pulsation amplitude calculated by a pressure pulsation fitting function.
6. The vane optimization control method for the hydraulic transition process of the water pump turbine based on the dynamic pressure pulsation simulation algorithm of claim 5 is characterized in that the bearing pressure of a volute is smaller than the maximum value of Ptotal (t) and smaller than a design allowable value, and the bearing pressure of a draft tube is larger than the minimum value of Ptotal (t) and larger than a vaporization pressure value.
7. The guide vane optimization control method for the hydraulic transition process of the water pump turbine based on the dynamic pressure pulsation simulation algorithm, which is disclosed in claim 1, is characterized in that in the step S4), a two-section broken line guide vane closing mode of 'fast before slow' is adopted, and the specific substeps are as follows: S41) quick closing segment On the premise of the rising permission of the rotating speed, the relative opening of the guide vane is quickly closed to a set value St1 from a full-open state in time T1 so as to avoid a severe pulsation area; S42) slow closing section The relative opening degree of the guide vane is closed from St1 to the buffer opening degree Sth in the time T2, the guide vane closing process is completed stably, and the final pressure fluctuation is slowed down.
8. The method for optimally controlling the guide vanes in the hydraulic transition process of the water pump turbine based on the dynamic pressure pulsation simulation algorithm according to claim 7, wherein the opening value St1 is smaller than 60%.

Description

Guide vane optimization control method for hydraulic transition process of water pump turbine based on dynamic pressure pulsation simulation algorithm Technical Field The invention relates to the technical field of hydroelectric equipment control, in particular to a guide vane optimization control method for a hydraulic transition process of a water pump turbine based on a dynamic pressure pulsation simulation algorithm. Background In the technical field of hydroelectric equipment control, a water pump turbine is a core device for power generation of a pumped storage power station, but the water pump turbine is easily impacted by huge water flow when in load shedding so as to be damaged, and the guide vane of the water pump turbine is scientifically closed so that the water pump turbine can effectively avoid the impact of huge water flow, thereby guaranteeing the safety and stability of the water pump turbine. However, the existing water pump turbine guide vane closing method has some defects in practical engineering application, specifically, the existing water pump turbine guide vane closing method generally adopts the method of predicting the pressure pulsation change in a water pump turbine volute and a draft tube on the basis of a one-dimensional hydraulic transient model and adding a constant pressure pulsation correction value based on engineering experience, and the technical parameters such as volute pressure, draft tube pressure, rising speed and regulating well water level are connected in parallel to optimize the water pump turbine guide vane closing rule, under the complex water flow impact condition, the pressure pulsation in a water pump turbine set flow channel presents strong time-varying characteristics, when the constant pressure pulsation correction value is adopted for correction, if the correction value is smaller, a large deviation exists between a prediction result and actual measurement data, the water flow pressure level in the water pump turbine set under extreme working conditions cannot be accurately estimated, and if the correction value is larger, the pressure resistance level of the water pump turbine set is improved, and engineering cost is increased. In addition, the traditional guide vane closing optimization method only focuses on technical parameters such as volute pressure, draft tube pressure, rotational speed rising pressure regulating well water level and the like, and does not bring the key technical parameter of pressure pulsation affecting the working state of the water pump turbine unit into an optimization target, so that a dead zone exists in the guide vane optimization method. Disclosure of Invention The invention aims to provide a guide vane optimization control method for a hydraulic transition process of a water pump turbine based on a dynamic pressure pulsation simulation algorithm. In order to achieve the above purpose, the present invention is realized by the following technical scheme: When the water pump turbine is in load shedding, the rotation speed of the unit and the pressure of the system can be caused to generate severe unsteady fluctuation, and various pressure pulsation sources with characteristic frequencies, such as rotation frequency, blade passing frequency, coupling response of vortex belts and water hammer and natural frequency of a pipe network, are excited. A large number of model tests and field actual measurements show that, despite the existence of broadband random noise caused by high-intensity turbulence and cavitation collapse in a water flow field, the pressure pulsation generally takes quasi-periodicity as a leading factor, has certain rules and predictable characteristics, and the pressure pulsation amplitude is closely related to the instantaneous speed of a unit and the opening degree of a guide vane, and is particularly characterized in that the pulsation intensity is obviously enhanced if the maximum speed stage corresponds to a larger opening degree of the guide vane, and the volute pressure peak is generally synchronous with the maximum speed moment. It is worth noting that the volute pressure is in a double-peak characteristic when the water pump turbine system throws load, namely, the first peak is mainly dominated by the water hammer mean pressure caused by the closing of the guide vane, the pulsation is weaker, and the second peak is caused by the combined action of the closing of the guide vane and the rising of the rotating speed, and the water hammer pressure is overlapped with the strong pulsation, so that a real dangerous working condition is formed. Therefore, the simple control of the water hammer mean pressure is insufficient to ensure the safe operation of the water pump turbine under the load shedding working condition, and the pressure pulsation parameter is required to be brought into the water pump turbine guide vane optimization closing method. Based on the cognition, the invention provides a guide vane