CN-116754148-B - Detection method suitable for water leakage of top cover of water turbine unit

CN116754148BCN 116754148 BCN116754148 BCN 116754148BCN-116754148-B

Abstract

A method for detecting water leakage of a top cover of a water turbine unit includes the steps of collecting sound print signals of the top cover, wherein the sound print signals comprise metal medium transmission sound print signals, air transmission sound print signals and liquid medium transmission sound print signals, filtering the metal medium transmission sound print signals, obtaining sound print phase displacement corresponding to different mediums according to the transmission speeds of sound in the different mediums, screening out the metal medium transmission sound print signals according to the sound print phase displacement, eliminating the metal medium transmission sound print signals, judging whether the top cover leaks or not, judging the rest sound print signals continuously according to the sound print phase displacement after eliminating the metal medium transmission sound print signals, and if the rest sound print signals only comprise air transmission sound print signals, proving that water leakage does not occur in the top cover, and if the sound print signals also comprise the liquid medium transmission sound print signals, proving that water leakage accidents occur in the top cover. The invention can overcome the defects of the traditional monitoring method and reduce the interference of water level fluctuation.

Inventors

BIAN QINGHUA
JIAO JIANGMING
ZHANG LU
ZHANG KUNFENG
ZOU LONG
CAO MENGYUN
You Sitong

Assignees

中国长江电力股份有限公司

Dates

Publication Date: 20260505
Application Date: 20230511

Claims (7)

1. The method for detecting water leakage of the top cover of the water turbine unit is characterized by comprising the following steps of: Step 1, collecting voiceprint signals of a top cover, wherein the voiceprint signals comprise metal medium transmission voiceprint signals, air transmission voiceprint signals and liquid medium transmission voiceprint signals; step 2, filtering metal medium transmission voiceprint signals, namely obtaining voiceprint phase displacement corresponding to different media according to the transmission speed of sound in the different media, screening out the metal medium transmission voiceprint signals according to the size of the voiceprint phase displacement, and removing the metal medium transmission voiceprint signals; And 3, judging whether the top cover leaks water or not, namely after removing the voiceprint signals transmitted by the metal medium, continuously judging the remaining voiceprint signals according to the voiceprint phase displacement, if the remaining voiceprint signals only have the voiceprint signals transmitted by the air, proving that the top cover does not leak water, and if the voiceprint signals also comprise the voiceprint signals transmitted by the liquid medium, proving that the top cover leaks water.
2. The method for detecting water leakage of the top cover of the water turbine unit, which is characterized in that in the step 1, a plurality of groups of voiceprint acquisition arrays are arranged on the top cover, the number of the voiceprint acquisition arrays is at least four, the four groups of voiceprint acquisition arrays are distributed in four directions of the top cover, each group of voiceprint acquisition arrays comprises at least three voiceprint collectors, the three voiceprint collectors of each group of voiceprint acquisition arrays are SC1, SC2 and SC3 respectively, the SC1, the SC2 and the SC3 are arranged on the same plumb line from bottom to top, and the respective distances are d1 meters; The metal medium propagation voiceprint signal source is an acoustic signal caused by vibration when the water turbine unit operates and an acoustic signal caused by the vibration of the top cover caused by environmental sound waves; the source of the airborne voiceprint signal is an acoustic signal caused by environmental vibration of the hydroelectric power plant; The liquid medium propagates the voiceprint signal, namely the acoustic wave signal after the voiceprint collector is immersed.
3. The method for detecting water leakage of the top cover of the water turbine unit according to claim 2, wherein in the step 2, the calculation process of the voiceprint phase displacement is as follows: The frequency, wavelength and speed of sound waves propagating in different media are as follows: u=λ*ν; u represents wave velocity, λ represents wavelength, and v represents frequency; The metal medium propagation signals acquired by each group of voiceprint acquisition arrays can generate corresponding voiceprint phase displacement due to different distances, and the voiceprint phase displacement meets the following conditions: If any voiceprint collector is taken as an origin O, the vibration of the origin is as follows: ; Wherein A is the amplitude of the vibration, In order to be of an angular frequency, For the initial phase, t represents the time, Representing displacement, wherein A, 、 Is a fixed value; The vibration of the P point of the other voiceprint collector of the group is as follows: ; in the formula, assuming that the point O is SC1, the point P is SC2, x corresponds to the distance d1 between SC1 and SC2, and if the point P is SC3, x corresponds to the distance 2d1 between SC3 and SC 1; assuming that point 0 is SC2, point P is SC1, x corresponds to the distance-d 1 between SC2 and SC1, and if point P is SC3, x corresponds to the distance d1 between SC3 and SC 2; assuming that point 0 is SC3, point P is SC1, x corresponds to the distance-2 d1 between SC3 and SC1, and if point P is SC2, x corresponds to the distance-d 1 between SC2 and SC 3; Because of = ;u= ; So the P point vibration wave function is ; Therefore, whether to filter the voiceprint signal transmitted by the metal medium or not is judged by analyzing the voiceprint phase displacement of the two voiceprint collectors through the frequency spectrum, and the same frequency is adopted The sound wave judgment conditions of (1) are as follows: 1) u Steel and iron is 5000 m/s, producing a phase shift of ; 2) U Water and its preparation method is 1500 m/s, ; 3) U Air-conditioner is 340 m/s, ; And comparing sound source signals of the two voiceprint collectors, wherein the sound source signal with the smallest phase difference is a metal medium sound wave, and filtering out the metal medium transmission voiceprint signals.
4. The method for detecting water leakage of a top cover of a water turbine unit according to claim 3, wherein when the top cover is judged to be water leakage, the following operations are further performed: And 4, starting and stopping the primary top cover pump and the standby top cover pump as follows: 1) When SC2 in the 4 groups of voiceprint acquisition arrays are immersed, a small amount of water leakage is indicated, the main top cover pump command is started, and when SC2 in the 4 groups of voiceprint acquisition arrays are not immersed, the main top cover pump command is stopped; 2) The SC3 of any 3 groups of voiceprint collectors are immersed, a large amount of water leakage is indicated, a top cover water level high limit alarm signal is given, a standby top cover pump command is started, the SC3 of the 3 groups of voiceprint collectors collected above are all disappeared by the immersed signal, and the standby top cover pump command is stopped.
5. The method for detecting water leakage of a top cover of a water turbine unit according to claim 4, wherein after the judgment in the step 4 is completed, comparing the pump stopping time T1 and the pump starting time T2 of the main top cover pump, and obtaining the water leakage size through linear calculation: Step 5, utilizing the formula = Comparing the water leakage amount, thereby giving an early warning: wherein T1-T2 represent drainage time, and d1 is the installation elevation difference of the voiceprint collector; Because the drainage capacity of the top cover pump is fixed, when I.e. When the water leakage amount is large, A larger value indicates a larger amount of water leakage, Smaller indicates smaller water leakage.
6. The method for detecting water leakage of a top cover of a water turbine unit according to claim 5, wherein after the judgment in the step 5 is completed, judgment of water drainage capacity is performed: Step 6, nth group event - = N+1st group event - = ; When (when) < When the current top cover of the surface has insufficient drainage capacity; Otherwise, the current roof drainage capacity is sufficient.
7. A detection system suitable for water leakage of a top cover of a water turbine set is characterized by adopting the detection method suitable for water leakage of the top cover of the water turbine set according to any one of claims 1-6, comprising a voiceprint collector, a voiceprint storage module, a voiceprint extraction module, a waveform calculation module, a logic calculation module and a signal output module, wherein the voiceprint collectors form a voiceprint collection array, geographic position information of the voiceprint collection array is used as one input quantity of the waveform calculation module, and the waveform calculation module is used for detecting the water leakage of the top cover of the water turbine set Waveform sum real time before t minutes The method comprises the steps of calculating a waveform at moment, wherein a waveform calculation result with time information becomes an input quantity of a logic calculation module, a judgment result after logic calculation becomes an input quantity of a signal output module, and the signal output module is used for forming linkage with a main top cover pump and a standby top cover pump.

Description

Detection method suitable for water leakage of top cover of water turbine unit Technical Field The invention belongs to the technical field of water leakage detection of a top cover of a water turbine unit, and particularly relates to a detection method suitable for water leakage of the top cover of the water turbine unit. Background The top cover is one of the important large parts of the water turbine, and is required to have sufficient strength and rigidity. The water flow guide plate has the functions of forming a flow passage together with the bottom ring, preventing water flow from overflowing, supporting guide vanes, a transmission mechanism, supporting guide vane bearings and other accessory devices. The top cover drainage system is one of necessary auxiliary systems of the hydroelectric generating set, no matter the set is in a power generation state or a shutdown state, water accumulation on the top cover is mainly caused by water leakage of a middle shaft sleeve of the guide vane, water leakage between the top cover and a large shaft and the like, and the top cover drainage pump serves as a core of the top cover drainage system and is used for draining leakage water accumulation to prevent water accumulation from causing flooding water guide bearings due to excessive water accumulation, so that the set is not scheduled to be shut down. The top cover drainage of the water turbine generally adopts two modes of self-flow drainage of a fixed guide vane or forced drainage of a top cover pump. The forced drainage system of the top cover pump mainly comprises a drainage pump, a water level monitoring system and a top cover pump start/stop logic control loop. The monitoring of the water level of the top cover is carried out by a water level sensor and a water level signal device, wherein the water level sensor outputs analog quantity to be sent to a monitoring system for monitoring and alarming the water level of the top cover in real time. The switching value node of the water level signal device is used for controlling the start and stop of the top cover pump, so that the purpose of draining the top cover accumulated water is achieved. At present, a water level switch is adopted to detect whether the top cover leaks water or not, and the following defects exist: 1. when the water level of the analog start-stop pump is close to the water level, the fluctuation of the water level in the reservoir causes misoperation of a water level switch; 2. when the installation positions of the water pumps are different, and when the installation positions of the sensors or the water inlets of the water reservoirs are far away from a certain water pump, the actual water level near the water pump is smaller than the measured value of the sensors when the water pump pumps water, so that when the water pump stops, the actual water level near the water pump exceeds the analog quantity of the water level sensor to stop the water level of the pump, and misoperation of a water level switch for stopping the pump near the water pump is caused; 3. If the water inflow suddenly increases, the water level rises faster, and in the process of the water pump reaching the analog start water level, program judgment, instruction sending, water pump starting and pipeline water filling, the water level rises to the vicinity of the start water level switch in a short time, so that the start water level switch is wrongly operated; 4. The water level difference between the analog quantity start-stop fixed value and the switching quantity start-stop fixed value is generally set smaller, if the distance between the analog quantity and the switching quantity is simply increased to prevent misoperation of the switch, the control requirement of the system water level cannot be met; 5. if the water level switch is continuously reset in abnormal action or the water level sensor is blocked at a certain position, the dynamic start-stop pump water level updating frequency is caused to be too high, so that the water pump start-stop water level dynamic control function enters an abnormal state; 6. If the water level switch is blocked at the highest position, the top cover pump is started and then the water level is not stopped even if the water level is reduced to the pump stopping position, so that the motor is burnt out due to idling; 7. the top cover of the water turbine is moist and complicated for a long time, greasy dirt and water pollutants are mixed together, and the floating ball of the water level switch is blocked by the sticky pollutants due to long-term chemical change and is difficult to avoid; 8. Because the water turbine top cap installation or long-term environment leads to the unbalanced top cap water level that leads to the communication hole to block up between each minute cistern to lead to the top cap water of top cap pump mounted position to have evacuated, but other minute cistern top cap water that does not install the top cap