CN-122021380-A - Method and system for predicting inlet water flow angle of high-pressure side of water pump turbine

CN122021380ACN 122021380 ACN122021380 ACN 122021380ACN-122021380-A

Abstract

The invention provides a method and a system for predicting a water flow angle of a high-pressure side inlet of a water pump turbine, and belongs to the technical field of hydraulic machinery. The method can at least partially solve the technical problems that in the prior art, the inlet water flow angle of the high-pressure side cannot be directly measured, the time consumption is too long due to CFD simulation calculation, and on-line monitoring is difficult to realize. The method comprises the steps of obtaining external operation parameters such as rotating speed and flow of a water pump turbine and geometric structure parameters such as diameter of a rotating wheel, calculating a flow field characteristic constant representing current flow field characteristics, collecting actual opening of a movable guide vane in real time, and calculating a high-pressure side inlet water flow angle by taking the opening of the movable guide vane and the flow field characteristic constant as input by using a preset flow field parameter coupling relation model. The invention can utilize the external data which is easy to obtain to quickly reversely push the internal key flow field parameters, thereby providing real-time data support for the safe and stable operation of the unit.

Inventors

KOU PANGAO
WU YONGHUA
YANG XIAO
SUN YANQING
ZUO FANGFEI
GUO CHAO
ZHAO HANCHEN
LU XU
YANG RUI
YANG CHENGLONG
HAN WEI
CHANG FENG
Bai Ruihuai

Assignees

华能陕西吴起发电有限公司
西安热工研究院有限公司
华能陕西发电有限公司

Dates

Publication Date: 20260512
Application Date: 20251217

Claims (10)

1. The method for predicting the inlet water flow angle of the high-pressure side of the water pump turbine is characterized by comprising the following steps: Acquiring external operation parameters and preset geometric parameters of a water pump turbine under the current working condition; calculating a flow field characteristic constant representing the flow field characteristic of the current working condition by using the external operation parameter and the geometric structure parameter ; The opening degree of the movable guide vane of the water pump turbine is acquired in real time through a sensor ; Calling a preset flow field parameter coupling relation model, and according to the opening degree of the movable guide vane And the flow field characteristic constant Calculating the inlet water flow angle of the high-pressure side ; The flow field parameter coupling relation model is constructed based on the inlet and outlet speed triangle relation of the water pump turbine.
2. The method for predicting the high-pressure side inlet water flow angle of a water pump turbine according to claim 1, wherein the flow field parameter coupling relation model satisfies the following relation: ; Wherein, the For the opening degree of the movable guide vane, For the high pressure side inlet water flow angle, Is the flow field characteristic constant.
3. The method for predicting the high-pressure side inlet water flow angle of a water pump turbine as set forth in claim 1, wherein said external operating parameters include a real-time rotational speed of the water pump turbine And real-time flow ; The geometric parameters include the diameter of the high-pressure side of the rotating wheel And the height of the runner blade 。
4. A method for predicting the high pressure side inlet water flow angle of a pump turbine as set forth in claim 3, wherein said flow field characteristic constant The calculation step of (1) adopts the following formula: ; Wherein, the Is the real-time flow of the water pump turbine, Is the real-time rotating speed of the water pump turbine, Is the height of the rotating wheel blade, Is the diameter of the high-pressure side of the rotating wheel, Is the circumference ratio.
5. The method for predicting the water flow angle at the high-pressure side inlet of a water pump turbine according to claim 1, wherein the flow field parameter coupling relation model is derived based on a speed triangle sine theorem of the water pump turbine under the working condition of the water pump turbine, and the speed triangle sine theorem is characterized in that: 。
6. the method for predicting the high-pressure side inlet water flow angle of a water pump turbine according to claim 1, wherein the runner blade height in the geometric parameters is Is of relative leaf height Diameter of high-pressure side of rotating wheel Is a product of (a) and (b).
7. The method for predicting the high-pressure side inlet water flow angle of a water pump turbine according to claim 1, further comprising: The calculated high-pressure side inlet water flow angle The control system is transmitted to the water pump turbine through an industrial communication protocol; The control system controls the inlet water flow angle of the high-pressure side Comparing the deviation value with a preset geometric angle of a blade inlet, calculating an impact angle deviation value, and sending an adjustment instruction to change the opening degree of a guide vane of the water pump turbine when the deviation value exceeds a safety threshold.
8. A system for predicting a high pressure side inlet water flow angle of a pump turbine, comprising: the parameter acquisition module is configured to receive the real-time rotating speed of the water pump turbine from the sensor And real-time flow And reading the preset high-pressure side diameter of the rotating wheel from a memory And the height of the runner blade ; The state monitoring module is configured to collect the opening degree of the movable guide vane of the water pump turbine ; A calculation processing module configured to first calculate the rotation speed Flow rate and flow rate Diameter of high-pressure side of runner And the height of the runner blade Calculating flow field characteristic constant Then based on a preset relation: Calculating the inlet water flow angle of the high-pressure side ; An output module configured to output the high pressure side inlet water flow angle To an external monitoring device.
9. The system for predicting the inlet water flow angle of the high-pressure side of the water pump turbine according to claim 8, wherein the parameter acquisition module comprises a rotation speed signal acquisition unit and a flow signal acquisition unit, wherein the rotation speed signal acquisition unit is connected to a fluted disc speed measurement sensor installed on a main shaft of the water pump turbine, and is configured to acquire pulse signals at a preset high-frequency sampling rate and analyze the pulse signals into real-time rotation speed The flow signal acquisition unit is connected to an ultrasonic flowmeter and an electromagnetic flowmeter arranged on the pressure steel pipe and is configured to acquire real-time flow ; The state monitoring module comprises a guide vane displacement acquisition unit, wherein the guide vane displacement acquisition unit is connected to a magnetostrictive displacement sensor arranged on a piston rod of a guide vane servomotor, and is configured to acquire guide vane displacement signals and convert the guide vane displacement signals into angle values ; The calculation processing module receives the rotating speed through an industrial field bus Flow rate and flow rate And angle value 。
10. The system for predicting the high side inlet water flow angle of a water pump turbine of claim 8, wherein the output module is communicatively coupled to a governor control unit of the water pump turbine; An optimal water flow angle comparison table is stored in the speed regulator control unit, and the comparison table comprises corresponding impact-free ideal water flow angle values under different working conditions; the speed regulator control unit is configured to receive the calculated value output by the calculation processing module Calculate the calculated value And the guide She Jieli sends a correction instruction to finely adjust the opening of the movable guide vane when the difference value indicates that the flow-off risk exists.

Description

Method and system for predicting inlet water flow angle of high-pressure side of water pump turbine Technical Field The invention belongs to the technical field of hydraulic machinery, and particularly relates to a method and a system for predicting a water flow angle of a high-pressure side inlet of a water pump turbine. Background In a pumped storage power station, a water pump turbine is used as core energy conversion equipment, and the running efficiency and stability of the unit are directly determined by the internal flow field characteristics of the water pump turbine. In the hydraulic design and operation analysis of a pump turbine, the high-pressure side inlet water flow angle (beta 1) is a critical internal flow field parameter. The parameter directly influences the impact loss of water flow entering the rotating wheel, and further influences the hydraulic efficiency and cavitation characteristics of the unit. If the inlet flow angle does not match the blade inlet setting angle, significant stall and swirl can occur, resulting in increased energy loss and even vibration. However, in the prior art approach, the high pressure side inlet water flow angle β1 is a typical internal parameter that is difficult to measure directly by a physical sensor. The main means of obtaining this parameter in the industry today is to rely on computational fluid dynamics, CFD simulation. Although CFD simulation can provide more detailed flow field information, it is complex to model, complex to grid divide, long in calculation period, and needs to consume a lot of calculation resources and time cost. This makes CFD methods difficult to apply in real-time engineering monitoring or rapid performance assessment. Thus, the prior art lacks a method to quickly and accurately infer the internal critical water flow angle β1 from easily measured external operating parameters. This limits the real-time perception and fine control of the operating state of the pump turbine. Disclosure of Invention The invention aims to at least solve one of the technical problems in the prior art and provides a method for predicting the inlet water flow angle of a high-pressure side of a water pump turbine. The method for predicting the inlet water flow angle of the high-pressure side of the water pump turbine comprises the following steps: Acquiring external operation parameters and preset geometric parameters of a water pump turbine under the current working condition; calculating a flow field characteristic constant representing the flow field characteristic of the current working condition by using the external operation parameter and the geometric structure parameter ; The opening degree of the movable guide vane of the water pump turbine is acquired in real time through a sensor; Calling a preset flow field parameter coupling relation model, and according to the opening degree of the movable guide vaneAnd the flow field characteristic constantCalculating the inlet water flow angle of the high-pressure side; The flow field parameter coupling relation model is constructed based on the inlet and outlet speed triangle relation of the water pump turbine. Further, the flow field parameter coupling relation model satisfies the following relation:; Wherein, the For the opening degree of the movable guide vane,For the high pressure side inlet water flow angle,Is the flow field characteristic constant. Further, the external operation parameters comprise real-time rotation speed of the water pump turbineAnd real-time flow; The geometric parameters include the diameter of the high-pressure side of the rotating wheelAnd the height of the runner blade。 Further, the flow field characteristic constantThe calculation step of (1) adopts the following formula:; Wherein, the Is the real-time flow of the water pump turbine,Is the real-time rotating speed of the water pump turbine,Is the height of the rotating wheel blade,Is the diameter of the high-pressure side of the rotating wheel,Is the circumference ratio. Further, the flow field parameter coupling relation model is derived based on a speed triangle sine theorem of the water pump turbine under the working condition of the water turbine, and the speed triangle sine theorem is characterized in that:。 further, the rotor blade height in the geometric parameters Is of relative leaf heightDiameter of high-pressure side of rotating wheelIs a product of (a) and (b). Further, the prediction method further includes: The calculated high-pressure side inlet water flow angle The control system is transmitted to the water pump turbine through an industrial communication protocol; The control system controls the inlet water flow angle of the high-pressure side Comparing the deviation value with a preset geometric angle of a blade inlet, calculating an impact angle deviation value, and sending an adjustment instruction to change the opening degree of a guide vane of the water pump turbine when the deviation value excee