A method for analyzing uneven opening fault of movable guide vane of water turbine

Abstract

The application discloses a method for analyzing uneven opening fault of movable guide vane of a hydraulic turbine, which comprises the following steps: acquiring the top cover horizontal vibration amplitude in the +X and +Y directions in real time according to the online monitoring system, calculating the top cover horizontal vibration monitoring value in real time, acquiring the top cover horizontal vibration waveform in the +X and +Y directions in real time, calculating the top cover horizontal vibration guide vane quantity k times frequency vibration component monitoring value, calculating the water guide shoe temperature range T in real time, judging three conditions in combination with the requirements of the industry standard specification, outputting a fault alarm signal when the three conditions are satisfied at the same time, stopping the machine in time to carry out inspection, and formulating maintenance treatment measures. The application is based on the equipment correlation phenomenon caused by uneven opening of the guide vane of the hydraulic turbine, and a method for analyzing whether the uneven opening fault of the guide vane exists is proposed by using a computer to carry out real-time calculation and analysis, so that the abnormal condition can be found in time and accurately at the initial stage of the uneven opening fault of the guide vane, maintenance treatment measures are formulated in time, and the application has good popularization value in the industry.

Description

Technical Field

[0001] This invention relates to a method for analyzing faults caused by uneven opening of the moving guide vanes of a hydro turbine, and more particularly to a method for automatic fault analysis and monitoring based on collected vibration waveforms and temperature data of a hydro generator, belonging to the field of hydro generator operating status monitoring technology. Background Technology

[0002] Guide vanes are one of the most important cast and forged components in the water guiding mechanism of a hydro-generator unit. They are used to regulate and control the flow of water entering the turbine runner. Therefore, guide vanes are also the most fundamental component for controlling the stable operation of the unit. Uneven guide vane opening will bring huge hidden dangers to the operation of the unit. Severe unevenness of the guide vane opening will cause the unit bearing temperature to rise rapidly, leading to accidental shutdown, and even causing serious damage to the hydro-generator unit equipment. However, when unevenness of the guide vane outlet does not cause serious impact, operators pay little attention to it on a daily basis. Moreover, due to the special location of the guide vanes, operators cannot inspect them during routine inspections when the unit is running or under normal shutdown. Generally, the guide vanes are only inspected during maintenance.

[0003] Currently, there is no direct monitoring method for uneven guide vane opening faults in hydroelectric turbines; all methods rely on manual analysis or big data analysis using computers. The published patent application CN11150289A, "A Fault Early Warning Method and Process for Uneven Opening of Hydroelectric Turbine Guide Vanes," uses an intelligent algorithm module to extract characteristic values ​​of vibrating equipment for fault early warning. The published patent application CN111692035B, "Uneven Guide Vane Opening and Detection Method and Process," also uses an intelligent algorithm module to improve the characteristic values ​​of vibrating equipment for fault early warning. However, neither of these published patent applications correctly analyzes the essential problem of uneven guide vane opening faults in hydroelectric turbines. Secondly, while computer AI autonomous learning is a commonly used method, AI autonomous learning calculations based on black boxes are mostly used for general big data operations. In the hydroelectric field, equipment operation data has a higher degree of specialization and mechanistic complexity, requiring more human thinking and professional knowledge during data processing. Due to the gap between their respective professional fields, AI algorithm designers often lack practical equipment operation and maintenance experience, resulting in AI-based conventional calculations of hydroelectric equipment characteristic values ​​that do not match reality. Ultimately, this prevents the widespread application of AI in the condition-based maintenance of hydroelectric equipment. Summary of the Invention

[0004] To monitor uneven guide vane opening faults in turbines in real time, and to detect and issue alarm signals in the early stages of the fault to prevent further escalation and unit accidents, this invention aims to create a system and method for real-time monitoring of uneven guide vane opening faults based on real-time acquisition of unit operating data. By analyzing the equipment correlation phenomena caused by uneven guide vane opening, this invention proposes a computer-based real-time calculation and analysis method to determine the existence of uneven guide vane opening faults.

[0005] This invention is achieved through the following technical solution: a method for analyzing the uneven opening of moving guide vanes in a water turbine, comprising the following steps:

[0006] (1) Based on the real-time horizontal vibration amplitude of the top cover in the +X and +Y directions obtained by the online monitoring system, the real-time horizontal vibration monitoring quantity Z of the top cover is calculated as follows:

[0007]

[0008] Where X represents the horizontal vibration amplitude of the top cover in the +X direction, Y represents the horizontal vibration amplitude of the top cover in the +Y direction, and Z represents the monitored value of the horizontal vibration of the top cover, that is, the combined value of the vibration in the two directions.

[0009] (2) Based on the real-time horizontal vibration waveform of the top cover in the +X direction obtained by the online monitoring system, the k-fold vibration component value of the guide vanes in the +X direction is calculated in real time using FFT (Fast Fourier Transform). The calculation formula is as follows:

[0010] X(k) = FFT[x{n}]| N

[0011] Where X(k) represents the k-fold frequency vibration component value of the horizontal vibration guide vanes of the top cover in the +X direction, x{n} represents the collected waveform data sequence in the +X direction, and N represents the number of data points in the data sequence;

[0012] (3) Based on the real-time horizontal vibration waveform of the top cover in the +Y direction obtained by the online monitoring system, the k-fold vibration component value of the guide vanes in the +Y direction is calculated in real time using FFT (Fast Fourier Transform). The calculation formula is as follows:

[0013] Y(k) = FFT[y{n}]| N

[0014] Where Y(k) represents the k-fold vibration component value of the horizontal vibration guide vanes of the top cover in the +Y direction, y{n} represents the collected waveform data sequence in the +Y direction, and N represents the number of data points in the data sequence;

[0015] (4) Based on the k-fold vibration component values ​​of the number of horizontal vibration guide vanes of the top cover in the +X direction and the k-fold vibration component values ​​of the number of horizontal vibration guide vanes of the top cover in the +Y direction calculated in steps (2) and (3), the monitoring quantity Z(k) of the k-fold vibration component of the number of horizontal vibration guide vanes of the top cover is calculated in real time. The calculation formula is as follows:

[0016]

[0017] Where X(k) represents the k-fold frequency vibration component value of the top cover horizontal vibration in the +X direction, Y(k) represents the k-fold frequency vibration component value of the top cover horizontal vibration in the +Y direction, and Z(k) represents the monitored quantity of the k-fold frequency vibration component of the top cover horizontal vibration guide vanes, that is, the composite quantity of vibration in the two directions.

[0018] (5) Based on the temperature measurements of N water-conducting tiles obtained from the online monitoring system, the maximum tile temperature is calculated in real time using the following formula:

[0019] Tmax = MAX{T1,T2,T3,...TN}

[0020] Where Tmax represents the maximum temperature of N water-conducting tiles, and T1~TN represent the temperature of each water-conducting tile;

[0021] (6) Based on the temperature measurements of N water-conducting tiles obtained by the online monitoring system, the minimum tile temperature is calculated in real time using the following formula:

[0022] Tmin = MIN{T1,T2,T3,...TN}

[0023] Where Tmin represents the minimum temperature of N water-conducting tiles, and T1~TN represent the temperature of each water-conducting tile;

[0024] (7) Based on the maximum and minimum water-conducting tile temperatures calculated in steps (5) and (6), the water-conducting tile temperature range T is calculated in real time. The calculation formula is as follows:

[0025] T = Tmax - Tmin

[0026] Where T represents the temperature range of the water-conducting tiles, Tmax represents the maximum temperature of the N water-conducting tiles, and Tmin represents the minimum temperature of the N water-conducting tiles;

[0027] (8) Based on the horizontal vibration monitoring quantity Z of the top cover calculated in step (2), the number of k-fold vibration components of the horizontal vibration guide vanes of the top cover calculated in step (4), and the temperature range T of the water guide tile calculated in step (7), and in accordance with the requirements of industry standards and specifications, the following judgments are made:

[0028] ① The number of horizontal vibration guide vanes of the top cover k-fold vibration component Z(k) > the monitoring quantity of horizontal vibration of the top cover Z×50%;

[0029] ② The monitored value Z of the horizontal vibration of the top cover is greater than the set value A, where A represents the allowable value of the horizontal vibration of the top cover when the vertical hydro-generator unit is running normally, referring to GB_T15468 "Basic Technical Conditions for Hydro-generators";

[0030] ③ The temperature difference T of the water guide bearing is greater than the fixed value C, where C represents the allowable temperature deviation of the water guide bearing during normal operation of the vertical hydro turbine generator unit, referring to the bearing temperature difference requirements in the "Huaneng Hydropower High-Quality Unit Standard";

[0031] (9) Under normal operating conditions of the unit, the three conditions in step (8) are judged in real time. When they are met at the same time, a fault alarm signal is output.

[0032] (10) Upon receiving a fault alarm signal, promptly stop the machine to conduct an inspection and formulate maintenance and repair measures.

[0033] The online monitoring system is an existing hydropower plant computer monitoring system and unit status monitoring system; the online monitoring system is existing technology and can acquire in real time the horizontal vibration amplitude of the top cover in the +X and +Y directions, the horizontal vibration waveform of the top cover in the +X and +Y directions, and the temperature measurement values ​​of N water-conducting tiles, etc.

[0034] The present invention has the following advantages and effects:

[0035] Currently, there is no reliable monitoring device or analysis method for uneven guide vane opening faults in hydro turbines. This invention provides an accurate real-time detection system and method for uneven guide vane opening faults in hydro turbines. It can detect abnormalities in a timely and accurate manner in the early stages of uneven guide vane opening faults, and formulate maintenance and treatment measures in a timely manner. It is of great significance for the monitoring of hydro turbines and has great promotion value in the industry. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0037] Figure 1 This is a schematic flowchart of the guide vane opening unevenness fault analysis method of the present invention;

[0038] Figure 2 A waveform diagram plotted for the point values ​​of the horizontal vibration waveform sequence of the top cover in the +X direction in Example 1;

[0039] Figure 3 The waveform diagram is plotted for the point values ​​of the horizontal vibration waveform sequence of the top cover in the +Y direction of Example 1. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the present invention clearer, specific embodiments are described below, with reference to the appendix. Figure 1The embodiments of the present invention will be described in further detail below.

[0041] Example 1

[0042] The automatic diagnosis of uneven guide vane opening fault in Unit 1 of a hydropower plant is further explained in detail below:

[0043] The online monitoring system is based on existing hydropower plant computer monitoring systems and unit status monitoring systems. The online monitoring system is based on existing technology and can acquire in real time the horizontal vibration amplitude of the top cover in the +X and +Y directions, the horizontal vibration waveform of the top cover in the +X and +Y directions, and the temperature measurement values ​​of N water guide tiles, etc.

[0044] (1) Based on the real-time acquisition of the horizontal vibration amplitude of the top cover in the +X and +Y directions by the online monitoring system, the monitoring quantity Z of the horizontal vibration of the top cover is calculated in real time. At a certain moment when the unit is running stably, the horizontal vibration amplitude of the top cover in the +X direction is 98 and the horizontal vibration amplitude of the top cover in the +Y direction is 105. The calculation formula is as follows:

[0045]

[0046] When the unit is running stably at a certain moment, X represents the horizontal vibration amplitude of the top cover in the +X direction, Y represents the horizontal vibration amplitude of the top cover in the +Y direction, and Z represents the monitored value of the horizontal vibration of the top cover, that is, the combined value of the vibration in the two directions.

[0047] (2) Based on the real-time horizontal vibration waveform of the top cover in the +X direction obtained by the online monitoring system, the k-fold vibration component value of the guide vanes in the +X direction is calculated in real time using FFT (Fast Fourier Transform). The calculation formula is as follows:

[0048] X(k) = FFT[x{n}]| N

[0049] Where X(k) represents the k-fold frequency vibration component value of the horizontal vibration guide vanes of the top cover in the +X direction, x{n} represents the collected waveform data sequence in the +X direction, and N represents the number of data points in the data sequence;

[0050] The system acquired eight consecutive cycles of horizontal vibration waveform data of the roof in the +X direction at the same moment, with 256 data points per cycle. The waveform plotted from the sequence of data points of the horizontal vibration waveform of the roof in the +X direction is shown below. Figure 2 ,

[0051] The number of movable guide vanes in Unit 1 is 24. Using FFT (Fast Fourier Transform), the value of the 24th harmonic vibration component of the top cover horizontal vibration guide vanes in the +X direction is calculated as follows:

[0052] X(24)=FFT[x{n}]| 2048 =78um

[0053] (3) Based on the real-time horizontal vibration waveform of the top cover in the +Y direction obtained by the online monitoring system, the k-fold vibration component value of the guide vanes in the +Y direction is calculated in real time using FFT (Fast Fourier Transform). The calculation formula is as follows:

[0054] Y(k) = FFT[y{n}]| N

[0055] Where Y(k) represents the k-fold vibration component value of the horizontal vibration guide vanes of the top cover in the +Y direction, y{n} represents the collected waveform data sequence in the +Y direction, and N represents the number of data points in the data sequence;

[0056] The system acquired eight cycles of continuous acquisition data of the horizontal vibration waveform of the top cover in the +Y direction at the same moment. Each cycle contained 256 data points. The waveform plotted from the sequence of data points of the horizontal vibration waveform of the top cover in the +Y direction is shown below. Figure 3 :

[0057] The number of movable guide vanes in Unit 1 is 24. Using FFT (Fast Fourier Transform), the value of the 24th harmonic vibration component of the top cover horizontal vibration guide vanes in the +X direction is calculated as follows:

[0058] Y(24)=FFT[y{n}]| 2048 =84

[0059] (4) Based on the k-fold vibration component values ​​of the number of horizontal vibration guide vanes of the top cover in the +X direction and the k-fold vibration component values ​​of the number of horizontal vibration guide vanes of the top cover in the +Y direction calculated in steps (2) and (3), the monitoring quantity Z(k) of the k-fold vibration component of the number of horizontal vibration guide vanes of the top cover is calculated in real time. The calculation formula is as follows:

[0060]

[0061] Where X(k) represents the k-fold frequency vibration component value of the top cover horizontal vibration in the +X direction, Y(k) represents the k-fold frequency vibration component value of the top cover horizontal vibration in the +Y direction, and Z(k) represents the monitored quantity of the k-fold frequency vibration component of the top cover horizontal vibration guide vanes, that is, the composite quantity of vibration in the two directions.

[0062] (5) Based on the temperature measurements of N water-conducting tiles obtained from the online monitoring system:

[0063] serial number 1 2 3 4 5 6 7 temperature 39.2 40.8 42.5 44.2 45.0 46.7 48.4 serial number 8 9 10 11 12 13 14 temperature 50.3 48.5 46.6 45.2 44.3 42.4 40.7

[0064] The maximum tile temperature is calculated in real time using the following formula:

[0065] Tmax=MAX{T1,T2,T3,...TN}=50.3℃

[0066] Where Tmax represents the maximum temperature of N water-conducting tiles, and T1~TN represent the temperature of each water-conducting tile;

[0067] (6) Based on the temperature measurements of N water-conducting tiles obtained from the online monitoring system:

[0068] serial number 1 2 3 4 5 6 7 temperature 39.2 40.8 42.5 44.2 45.0 46.7 48.4 serial number 8 9 10 11 12 13 14 temperature 50.3 48.5 46.6 45.2 44.3 42.4 40.7

[0069] The minimum tile temperature is calculated in real time using the following formula:

[0070] Tmin=MIN{T1, T2, T3,...TN}=39.2℃

[0071] Where Tmin represents the minimum temperature of N water-conducting tiles, and T1~TN represent the temperature of each water-conducting tile;

[0072] (7) Based on the maximum and minimum water-conducting tile temperatures calculated in steps (5) and (6): the water-conducting tile temperature range T is calculated in real time, and the calculation formula is as follows:

[0073] T=Tmax-Tmin=50.3-39.2=11.1℃

[0074] Where T represents the temperature range of the water-conducting tiles, Tmax represents the maximum temperature of the N water-conducting tiles, and Tmin represents the minimum temperature of the N water-conducting tiles;

[0075] (8) Based on the horizontal vibration monitoring quantity Z of the top cover calculated in step (2), the number of k-fold vibration components of the horizontal vibration guide vanes of the top cover calculated in step (4), and the temperature range T of the water guide tile calculated in step (7), and in accordance with the requirements of industry standards and specifications, the following judgments are made:

[0076] ① The number of horizontal vibration guide vanes of the top cover, k, and the harmonic vibration component Z(k) > the monitored value of the horizontal vibration of the top cover, Z × 50%; that is, 81 > 101.5 × 50% = 50.5

[0077] ② The horizontal vibration monitoring value Z of the top cover is greater than the set value A; 101.5>70; where A represents the allowable value of horizontal vibration of the top cover when the vertical hydro-turbine generator unit is running normally, and the allowable value of the unit at a speed of 100 rpm is 70um according to GB_T15468 "Basic Technical Conditions for Hydro-turbines";

[0078] ③ The temperature difference T of the water guide bearing is greater than the fixed value C; 11.1>8; where C represents the allowable temperature deviation of the water guide bearing during normal operation of the vertical hydro-turbine generator unit. According to the "Huaneng Hydropower High-Quality Unit Standard", the qualified bearing temperature difference requirement is 8℃.

[0079] (9) Under normal operating conditions of the unit, the three conditions in step (8) are judged in real time. When they are met at the same time, a fault alarm signal is output.

[0080] (10) Upon receiving a fault alarm signal, promptly stop the machine to conduct an inspection and formulate maintenance and repair measures.

[0081] According to this embodiment, the automatic monitoring and alarm of uneven turbine opening fault of Unit 1 of a power plant was implemented. The defect in the guide vane was detected in time, and maintenance was carried out in advance according to the unit status, which prevented the further escalation of the accident. This proves that the method of the present invention is accurate and feasible and is worth promoting.

Claims

1. A method for analyzing faults caused by uneven opening of moving guide vanes in a water turbine, characterized in that... Includes the following steps: (1) Based on the real-time horizontal vibration amplitude of the top cover in the +X and +Y directions obtained by the online monitoring system, the real-time horizontal vibration monitoring quantity Z of the top cover is calculated as follows: Where X represents the horizontal vibration amplitude of the top cover in the +X direction, Y represents the horizontal vibration amplitude of the top cover in the +Y direction, and Z represents the monitored value of the horizontal vibration of the top cover, that is, the combined value of the vibration in the two directions. (2) Based on the real-time horizontal vibration waveform of the top cover in the +X direction obtained by the online monitoring system, the k-fold vibration component value of the guide vanes in the +X direction is calculated in real time using FFT. The calculation formula is as follows: X(k)=FFT[x{n}]| N Where X(k) represents the k-fold frequency vibration component value of the horizontal vibration guide vanes of the top cover in the +X direction, x{n} represents the collected waveform data sequence in the +X direction, and N represents the number of data points in the data sequence; (3) Based on the real-time horizontal vibration waveform of the top cover in the +Y direction obtained by the online monitoring system, the k-fold vibration component value of the guide vanes in the +Y direction is calculated in real time using FFT. The calculation formula is as follows: Y(k)=FFT[y{n}]| N Where Y(k) represents the k-fold vibration component value of the horizontal vibration guide vanes of the top cover in the +Y direction, y{n} represents the collected waveform data sequence in the +Y direction, and N represents the number of data points in the data sequence; (4) Based on the k-fold vibration component values ​​of the number of horizontal vibration guide vanes of the top cover in the +X direction and the k-fold vibration component values ​​of the number of horizontal vibration guide vanes of the top cover in the +Y direction calculated in steps (2) and (3), the monitoring quantity Z(k) of the k-fold vibration component of the number of horizontal vibration guide vanes of the top cover is calculated in real time. The calculation formula is as follows: Where X(k) represents the k-fold frequency vibration component value of the top cover horizontal vibration in the +X direction, Y(k) represents the k-fold frequency vibration component value of the top cover horizontal vibration in the +Y direction, and Z(k) represents the monitored quantity of the k-fold frequency vibration component of the top cover horizontal vibration guide vanes, that is, the composite quantity of vibration in the two directions. (5) Based on the temperature measurements of N water-conducting tiles obtained from the online monitoring system, the maximum tile temperature is calculated in real time using the following formula: Tmax = MAX{T1,T2,T3,...TN} Where Tmax represents the maximum temperature of N water-conducting tiles, and T1~TN represent the temperature of each water-conducting tile; (6) Based on the temperature measurements of N water-conducting tiles obtained by the online monitoring system, the minimum tile temperature is calculated in real time using the following formula: Tmin = MIN{T1,T2,T3,...TN} Where Tmin represents the minimum temperature of N water-conducting tiles, and T1~TN represent the temperature of each water-conducting tile; (7) Based on the maximum and minimum water-conducting tile temperatures calculated in steps (5) and (6), the water-conducting tile temperature range T is calculated in real time. The calculation formula is as follows: T = Tmax - Tmin Where T represents the temperature range of the water-conducting tiles, Tmax represents the maximum temperature of the N water-conducting tiles, and Tmin represents the minimum temperature of the N water-conducting tiles; (8) Based on the horizontal vibration monitoring quantity Z of the top cover calculated in step (2), the number of k-fold vibration components of the horizontal vibration guide vanes of the top cover calculated in step (4), and the temperature range T of the water guide tile calculated in step (7), and in accordance with the requirements of industry standards and specifications, the following judgments are made: ① The number of horizontal vibration guide vanes of the top cover k-fold vibration component Z(k) > the monitoring quantity of horizontal vibration of the top cover Z×50%; ② The monitored value Z of the horizontal vibration of the top cover is greater than the set value A, where A represents the allowable value of the horizontal vibration of the top cover when the vertical hydro-generator unit is running normally; ③ The temperature difference T of the water guide tile is greater than the fixed value C, where C represents the allowable temperature deviation of the water guide tile when the vertical hydro-generator unit is running normally; (9) Under normal operating conditions of the unit, the three conditions in step (8) are judged in real time. When they are met at the same time, a fault alarm signal is output. (10) Upon receiving a fault alarm signal, promptly stop the machine to conduct an inspection and formulate maintenance and repair measures.

2. The method for analyzing the uneven opening of the moving guide vanes of a water turbine according to claim 1, characterized in that: The online monitoring system is the existing computer monitoring system and unit status monitoring system of the hydropower plant.

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