CN116892479A

CN116892479A - Central operation air supplementing device for full-load range of intelligent constant-vacuum mixed-flow water turbine generator set

Info

Publication number: CN116892479A
Application number: CN202310952113.0A
Authority: CN
Inventors: 吴博恩
Original assignee: Individual
Current assignee: Individual
Priority date: 2023-07-26
Filing date: 2023-07-26
Publication date: 2023-10-17

Abstract

An intelligent constant-vacuum mixed flow water turbine generator set full load range central operation air supplementing device is provided with a floating ball, an air blocking pipe, an outer shaft table, an inner sleeve, an outer sleeve thread, a hollow rotating shaft with a central hole of an adjusting shaft and a Kong Zhuixing valve disc in a valve disc, wherein the valve disc is placed under a valve disc seat with a conical valve port. A fish-eye bearing seat is sleeved on the hollow rotating shaft, and a U-shaped plate is used for fixing the wind-dividing ring cavity with the rubber sealing ring and the inlet pipe in the air-supplementing chamber with the cover plate. The movable middle shaft with the vacuum cavity is connected with the bearing seat and the telescopic rod of the servo electric cylinder on the beam by using a tension sensor. The vacuum sensor is screwed into the vacuum chamber. The split annular cavity cover with the arc-shaped air dividing plate, the arc-shaped air guiding plate, the annular cavity pressure sensor and the split sealing table is arranged on the split annular cavity with the inlet pipe, and the air supplementing pipe is internally provided with an air speed sensor. The vacuum cavity is communicated with the air supplementing cavity, and sensors such as pressure, vacuum, wind speed, tension and the like of the annular cavity and the signal wire for the servo electric cylinder are connected with a control module unit with a power supply cable and a command cable. The invention is used in the field of air supplement of water turbines.

Description

Central operation air supplementing device for full-load range of intelligent constant-vacuum mixed-flow water turbine generator set

Technical field:

the invention relates to an intelligent constant vacuum central operation air supplementing device for a mixed flow type water turbine unit in the whole process of generating power from the lowest load to the rated load.

The background technology is as follows:

at present, the mixed-flow water turbine adopts a mechanical type center operation air supplementing device, the air supplementing device adopts a spring to control the air supplementing stroke of a valve disc to control the air supplementing amount, and the air supplementing device is not only marginally applied to the natural air supplementing stage of the mixed-flow water turbine, but also can not meet the air supplementing amount of the forced air supplementing stage of the mixed-flow water turbine. The air supplementing device cannot meet the technical requirement of constant vacuum degree air supplementing of the mixed-flow water turbine, because the mixed-flow water turbine only needs to generate a vacuum region to cause vibration of the mixed-flow water turbine generator set when the mixed-flow water turbine forms an aMpa vacuum region in the operation process, at the moment, a valve disc is required to be compressed under the action of vacuum degree to open and supplement a large amount of air, so that the vacuum degree of the vacuum region generated by the mixed-flow water turbine is not increased continuously, but at the moment, the valve disc and the valve port of the air supplementing valve are in an opening critical state, a large amount of air needs to be supplemented into the vacuum region from an overflow ring between the valve disc and the valve port, a large amount of air needs to be supplemented into the vacuum region, the mixed-flow water turbine generates a larger vacuum degree bMpa to suck the valve disc downwards to a sufficient stroke, and the distance between the valve disc and the valve port is increased so as to increase the overflow ring zone of the supplemented air, and the vacuum degree of the vacuum region is not increased any more through the air supplementing cavity and a central air supplementing pipeline. However, the vacuum degree corresponding to the stroke of the valve disc is the same as the vacuum degree b mpa, the vacuum degree b mpa is far greater than the technical requirement that a large amount of air is required to be fed when the water turbine is required to form the vacuum degree a mpa, if the air feeding device in the prior art is required to feed a large amount of air into the vacuum area when a mpa is formed, the mixed flow water turbine can not generate severe vibration and cavitation, and huge damage is brought to the water turbine generator set; the air supplementing device in the prior art can not supplement a large amount of air to the vacuum area when the vacuum degree reaches the bMpa, the valve disc stroke can reach the requirement of supplementing a large amount of air only when the vacuum degree reaches the bMpa, and the mixed flow type water turbine generator set can vibrate severely when the vacuum area reaches the bMpa. Therefore, the mechanical air supplementing device in the prior art not only can not meet the technical requirement of forced air supplementing, but also can not meet the technical requirement of natural air supplementing of the mixed-flow water turbine, and the air supplementing device is more suitable for supplementing air to a huge vacuum area generated instantaneously during emergency shutdown and preventing tail water from flowing backward to flood the generator set. The mechanical air supplementing device has the defects of the principle and the technology, and also has the defects of spring deformation, rust, difficult processing technology of a buffer and large overall weight, and is arranged on the air supplementing cavity at the end part of the large shaft, so that a certain influence is brought to the upper guide bearing. At present, the mixed-flow hydraulic turbine urgent need an intelligent and constant vacuum degree, be fit for generating set operation load overall process's novel air supplement unit, this novel air supplement unit's air supplement stroke does not receive the spring influence, and vacuum degree aMpa is invariable in the air supplement process, still should have good reliability, light in weight and intelligent high technical characteristics of level to replace mechanical type center operation air supplement unit among the prior art, satisfy mixed-flow hydraulic generator set's best operation technical requirement.

The invention comprises the following steps:

the technical scheme provided by the invention perfectly solves a plurality of problems of the mechanical type central operation air supplementing device in the prior art, and completely meets the optimal technical requirement of air supplementing in the full load range of the mixed flow type hydroelectric generating set by adopting a simple and smart structure and a high intelligent level, thereby providing reliable and advanced technical guarantee for safe and efficient operation power generation of the mixed flow type hydroelectric generating set. The main technical characteristics are as follows: a wind blocking pipe with an upper hole and an arc sealing ring is fixed at the central position below a conical valve disc with a valve disc central hole in a sealing mode, a floating ball is placed at the lower end of the inner part of the wind blocking pipe through 4 support plates and a supporting ring, 4 support plates are fixed at the lower end of the inner part of the wind blocking pipe, a valve disc seat with a conical valve port and a conical valve disc are concentrically fixed on a flange of the air blocking cavity through a flange hole, an air supplementing cavity flange and a bolt, a central air supplementing pipeline is fixed below the air supplementing cavity, the central air supplementing pipeline is communicated with a mixed flow water turbine vacuum area, an outer belt shaft table, a pipe thread and a hollow rotating shaft with an adjusting shaft central hole are fixed at the upper central position above the conical valve disc through a flange hole on a base flange, a bearing seat with a fisheye bearing and an outer sleeve in a sealing mode is sleeved on the hollow rotating shaft, the inner sleeve is sleeved on the hollow rotating shaft and is propped against the fisheye bearing, the fisheye bearing inner surface of the fisheye bearing seat is sealed with the inner bearing seat, the fisheye bearing sleeve hole is in a sealing fit with the hollow sealing mode, the fisheye bearing sleeve is provided with a spherical surface, a spherical surface is fixed on the flange is in a sealing mode, the sealing hole is connected with the flange through the lower end of the valve disc through the pipe central hole and the sealing ring, and the sealing ring is fixed at the upper end of the air sealing ring is in a sealing port 3 through the flange is connected with the air sealing pipe through the air sealing hole, and the sealing ring is in a sealing pipe sealing sleeve, and the sealing hole is in a sealing mode is in contact with the sealing pipe; the annular cavity pressure sensor is fixed on a split annular cavity cover with an arc-shaped air deflector through a through hole by a screw cap, the split annular cavity cover is provided with a split sealing table, the split sealing table is provided with a split guide hole and a sealing belt, the split annular cavity cover with the arc-shaped air deflector is fixed on a split annular cavity opposite to an inlet pipe, the split annular cavity cover with the arc-shaped air deflector is symmetrical, the other split annular cavity cover with the arc-shaped air deflector is fixed on the split annular cavity with one side of the inlet pipe, and the center lines of the arc-shaped air deflector and the arc-shaped air deflector are both overlapped with an X axis; the front end of the vacuum sensor is screwed into the vacuum cavity through a mounting screw hole on the mounting boss, and then is fixed by a screw cap; the movable center shaft is connected with a telescopic rod of a servo electric cylinder through a tension sensor through bolts, the servo electric cylinder is fixed below a cross beam through bolts, two ends of the cross beam are respectively fixed on 2L-shaped plates, and the 2L-shaped plates are respectively fixed on the inner side of the air supplementing chamber through bolts; the servo electric cylinder, the vacuum sensor, the annular cavity pressure sensor and the air speed sensor are connected with a control module unit with a power cable and an instruction cable through signal wires, screw joints are arranged on the signal wires of the tension sensor and the vacuum sensor, the adjusting shaft middle hole is communicated with the vacuum cavity on the movable middle shaft through a communicating cavity, and the cover plate is fixed on the mounting opening of the air supplementing chamber through a flange hole and a flange screw hole through bolts.

The floating ball and the arc-shaped sealing ring mainly seal working water from the draft tube, and the floating ball floats after the working water comes up, and the arc-shaped sealing ring is blocked by the floating ball, so that the working water cannot enter the vacuum cavity through the upper hole, the valve disc middle hole, the adjusting shaft middle hole and the communicating cavity. The fish-eye bearing with high axial load force is mainly used for solving the technical problems that the movable center shaft, the conical valve disc and the conical valve port are aligned, so that the sealing property of the conical valve disc and the conical valve port is good, and meanwhile, the movable center shaft and the conical valve disc are prevented from rotating together, and the inner sleeve and the outer sleeve of the fish-eye bearing have good contact rotation sealing performance; the fish-eye bearing outer sleeve and the inner surface of the bearing seat, and the fish-eye bearing inner sleeve and the hollow rotating shaft are all installed in a sealing mode. The wind blocking pipe and the conical valve disc are also installed in a sealing mode, such as water-resistant sealant is smeared at the installation position. The arc-shaped air dividing plate divides a large amount of air to be supplemented into two parts, the air of the two parts supplements the air to the air supplementing cavity along the circumference of the inner surface of the air dividing annular cavity, and the arc-shaped air dividing plate has the main effect of avoiding the air flow from collision in the air dividing annular cavity to generate flocculation flow and affecting the air supplementing effect of the vacuum area. The split ring cavity cover is convenient to install and overhaul, and the split butt joint surface can adopt a vertical plate sealing handle structure. A screw joint is designed on signal wires of the tension sensor and the vacuum sensor, and the main purpose is that the two sensors move up and down along with a telescopic rod of a servo electric cylinder, the screw joint provides telescopic quantity for the signal wires, the two sensors can work conveniently, and a fixing structure can be additionally arranged at a leading-out end of the screw joint. The control module unit sets a sensor monitoring threshold value according to an instruction transmitted by the instruction cable to accurately and quickly control the servo electric cylinder; the control module unit can provide an optimal air supplementing control scheme for the mixed-flow water turbine by adopting a mathematical model and an algorithm according to the optimal efficiency value, the minimum vibration value and other related parameters of the generator set, reasonably and effectively implement intelligent air supplementing for the generator set from the lowest load to the rated load, and generate power in an optimal state for the mixed-flow water turbine generator set in the full load range, so that the phenomenon that the mixed-flow water turbine generates harmful vacuum areas due to the fact that the mixed-flow water turbine breaks away from the rated working condition is thoroughly eliminated, and the phenomenon that the generator set vibrates severely due to the harmful vacuum areas is avoided.

The technical effects achieved by the technical scheme provided by the invention are realized as follows: firstly, setting a monitoring threshold value of a vacuum sensor and a tension sensor through a control module unit, when the vacuum degree in a gas supplementing cavity reaches aMpa, the tension static change quantity of the tension sensor reaches ΔF=the weight of a movable part sleeve +S.P, S is the effective area of a conical valve disc, P is the vacuum degree in the gas supplementing cavity, the vacuum degree is the vacuum degree of a harmful vacuum area generated when a mixed-flow water turbine is separated from a rated working condition, and the vacuum degree aMpa is transmitted into the vacuum cavity through a central gas supplementing pipeline, the gas supplementing cavity, a regulating shaft middle hole and a communicating cavity. The weights of the conical valve disc, the wind blocking pipe, the bearing component and the moving center shaft in the moving part sleeve are constant when the moving part sleeve is static, the effective area of the conical valve disc is unchanged, delta F is changed only when the vacuum degree P is changed from 0 to a, so that delta F is changed only when the vacuum degree P is changed, and when the vacuum degree P reaches aMpa, the delta F=S.aMpa value is the monitoring threshold value set by the tension sensor.

The vacuum degree of the vacuum area generated by the mixed flow water turbine is transmitted into the vacuum cavity through the central air supplementing pipeline, the air supplementing cavity, 4 support plates below the wind shielding pipe, the floating ball, the arc-shaped sealing ring, the upper hole, the valve disc middle hole, the adjusting shaft middle hole and the communicating cavity, and the vacuum degree transmitted into the vacuum cavity is monitored in real time by the vacuum sensor and data are transmitted to the control module unit. When the vacuum sensor monitors that the vacuum degree in the vacuum cavity reaches an aMpa, the monitoring threshold value is transmitted to the control module unit through the signal wire, the control module unit controls the downward moving speed and the downward moving stroke of the telescopic rod of the servo electric cylinder according to the mathematical model and the algorithm, and a large amount of air is fed into a vacuum area formed by the mixed flow water turbine through the air feeding pipe, the inlet pipe, the air distribution annular cavity, the conical valve port, the air feeding cavity and the central air feeding pipeline. In the whole process of air filling, whether the vacuum degree meets the aMpa or not is monitored by a vacuum sensor, the aMpa is the optimal air filling vacuum degree of the generator set during the highest efficiency and the smallest vibration, and at the moment, the generator set does not vibrate severely, and the working efficiency is highest. When the vacuum sensor monitors that the current vacuum degree value is larger than aMpa, the reasonable stroke of the conical valve disc is enlarged according to a mathematical model and an algorithm, namely the air supplementing quantity is increased, and the vacuum degree of a vacuum area is prevented from being increased; when the vacuum sensor monitors that the current vacuum degree monitoring value is smaller than the aMpa, the reasonable stroke of the conical valve disc is reduced according to a mathematical model and an algorithm, so that the supplemented air quantity is reduced, the vacuum degree value is restored to the vacuum degree monitoring threshold aMpa, and the air supplementing quantity at the moment does not reduce the working efficiency of the mixed-flow water turbine and does not vibrate the mixed-flow water turbine; meanwhile, the algorithm is set in real time according to the annular cavity pressure sensor and the wind speed sensor, so that the air quantity fed into the vacuum area is more accurate. When the vacuum sensor fails and cannot work normally, the control module unit is switched into the tension sensor to monitor the vacuum degree through the change of delta F in real time, and the vacuum sensor is maintained or replaced after the machine is stopped. Because the moving stroke of the conical valve disc is realized by controlling the servo electric cylinder according to the value monitored by the vacuum sensor, the air supplementing process of the mixed flow type hydroelectric generating set is carried out under the condition of constant vacuum degree of aMpa, and the area of the overflow girdle between the conical valve disc and the conical valve port is realized by actively regulating the stroke of the telescopic rod by the servo electric cylinder, so the air supplementing process is realized at aMpa from beginning to end. The optimal air supplementing vacuum degree aMpa value can be set at any time according to the operation working condition of the mixed flow type hydroelectric generating set, and is flexible and convenient. A large amount of air fed into the vacuum area can be smoothly fed into the vacuum area through the arc-shaped air dividing plate and the arc-shaped air guide plate in the air dividing ring cavity, and air flocculation flow cannot be generated in the air dividing ring cavity to influence the air supplementing effect. The floating ball is mainly used for sealing tail water to the communicating cavity, and hidden danger is brought to the fish-eye bearing and the vacuum sensor. The fish-eye bearing can adjust concentricity and verticality of the conical valve disc and the movable center shaft and the conical valve port, the fish-eye bearing can prevent the closed conical valve disc from driving the upper and lower movable center shafts to rotate, so that the movable center shaft drives the tension sensor and the servo electric cylinder to rotate together, the technical problem that the movable center shaft does not rotate together with the conical valve disc is solved by adopting the fish-eye bearing with high axial load because the air supplementing cavity and the valve disc seat rotate together with the water turbine, the conical valve disc is fixed on an inner ring of the fish-eye bearing through a hollow rotating shaft, and the inner ring can rotate while an outer ring of the fish-eye bearing does not rotate. The movable middle shaft is fixed on the bearing seat of the outer ring of the fish-eye bearing. The friction force of the fish-eye bearing is extremely small, the friction force can not drive the movable center shaft to rotate, and the anti-rotation structure of the servo electric cylinder can completely overcome the problem. The split sealing platform is used for sealing the dynamic and static positions of the movable center shaft, and a sealing belt is also arranged in the split sealing platform. The rubber sealing ring on the outlet pipe is in contact with the upper surface of the valve disc seat for sliding sealing, so that the dynamic and static positions of the wind distributing ring cavity and the valve disc seat are good in sealing performance. The function of the air blocking pipe is to prevent the air to be supplemented from affecting the vacuum degree in the vacuum cavity, the length of the air blocking pipe can be properly prolonged, meanwhile, the algorithm of the control module unit also considers the influence of jet vacuum degree caused by jet effect generated at the end part of the air blocking pipe on the air supplementing vacuum degree aMpa, the influence can be corrected through a mathematical model and the algorithm, the diameter of the conical valve disc is far greater than the diameter of the air blocking pipe, and thus the jet vacuum degree generated by the jet effect can be greatly reduced.

The technical scheme provided by the invention perfectly solves the technical problem of constant vacuum degree air supplement of the mixed-flow water turbine, solves the problem that the mechanical center operation air supplement device in the prior art cannot meet the optimal air supplement technical requirement of the mixed-flow water turbine, has novelty, creativity and practicability compared with the prior art, and is necessarily widely applied to the field of mixed-flow water turbine generator sets.

Description of the drawings:

FIG. 1 is a front view of an intelligent constant vacuum mixed flow hydroelectric generating set full load range center operation air supplementing device

FIG. 2 is a view of A-A of an intelligent constant-vacuum mixed flow hydroelectric generating set full-load range center operation air supplementing device

FIG. 3 is a view of an intelligent constant vacuum mixed flow hydroelectric generating set full load range center operation air supplementing device B-B

FIG. 4 is an enlarged view of the intelligent constant vacuum mixed flow hydroelectric generating set full load range center operation air supplementing device I

FIG. 5 is an N-directional view of an intelligent constant vacuum mixed flow hydroelectric generating set full load range center operation air supplementing device

FIG. 6 is a K-direction view of the intelligent constant vacuum mixed flow hydroelectric generating set full load range center operation air supplementing device

Wherein:

1. air supplementing chamber 2, bolt 3 and U-shaped plate

4. Wind-dividing ring cavity 5, mounting flange 6 and flange hole

7. Split ring cavity cover 8, arc air deflector 9 and L-shaped plate

10. Cover plate 11, mounting opening 12 and cross beam

13. Servo electric cylinder 14, telescopic rod 15 and tension sensor

16. Mounting boss 17, mounting screw hole 18, vacuum sensor

19. Signal line 20, screw joint 21 and annular cavity pressure sensor

22. Via hole 23, screw cap 24 and split sealing table

25. Pipe thread 26, center nut 27, inner sleeve

28. Fisheye bearing 29, aligning hole 30 and conical valve port

31. Valve disk middle hole 32, upper hole 33 and arc-shaped sealing ring

34. Floating ball 35, supporting ring 36 and supporting plate

37. Wind blocking pipe 38, conical valve disc 39 and base flange

40. Outer pillow block 41, hollow shaft 42, bearing block

43. Outer sleeve 44, bearing seat flange 45 and center shaft flange

46. Communication cavity 47, adjusting shaft middle hole 48 and connecting flange

49. Inlet pipe 50, arc-shaped air dividing plate 51 and sealing belt

52. Split guide hole 53, vacuum cavity 54, moving center shaft

55. Flange screw hole 56, power cable 57, instruction cable

58. Control module unit 59, air supplementing pipe 60 and wind speed sensor

61. Air supplementing cavity flange 62, outlet pipe 63 and rubber sealing ring

64. Air supplementing cavity 65, valve disc seat 66 and central air supplementing pipeline

The specific embodiment is as follows:

the floating ball 34 is placed in the wind shielding pipe 37 through 4 support plates 36 and supporting rings 35, the 4 support plates 36 are fixed at the lower end of the wind shielding pipe 37, the upper end of the inside of the wind shielding pipe 37 is provided with an arc-shaped sealing ring 33 and an upper hole 32, and the wind shielding pipe 37 is fixed at the center position below a conical valve disc 38 with a valve disc middle hole 31 through a mounting flange 5 by bolts 2. A hollow rotary shaft 41 with an outer pillow block 40, a pipe thread 25 and an adjusting shaft middle hole 47 is fixed on the upper center position of a conical valve disc 38 through a flange hole 6 on a base flange 39 by bolts 2. A valve disc seat 65 with a conical valve port 30 is concentrically fixed on a flange 61 of a supplementing cavity by bolts 2 and a supplementing cavity 64 through a flange hole 6, and a central supplementing pipe 66 is arranged in the supplementing cavity 64 and is communicated with a vacuum area in the water turbine. The outer sleeve of the fish-eye bearing 28 is placed in a sealing manner in a bearing seat 42 with a centering hole 29 on the lower surface and a bearing seat flange 44 on the upper surface, the bearing seat 42 is sleeved on a hollow rotating shaft 41 in a sealing manner through the inner sleeve of the fish-eye bearing 28, the inner sleeve 27 is sleeved on the hollow rotating shaft 41 on the fish-eye bearing 28, a central screw cap 26 is screwed on the upper end of the inner sleeve 27 through a pipe thread 25, and the outer sleeve 43 is placed in the bearing seat 42.

The air distribution ring cavity 4 with the rubber seal ring 63 fixed below through the outlet pipe 62 is fixed inside the air supplementing chamber 1 by 3U-shaped plates 3, so that the rubber seal ring 63 is in sliding contact with the upper surface of the valve disc seat 65 and is concentric and perpendicular to the conical valve port 30. The inlet pipe 49 of the wind-dividing ring cavity 4 is communicated with the air supplementing pipe 59 through the connecting flange 48 by bolts 2, and the wind speed sensor 60 is fixed inside the air supplementing pipe 59 through the mounting boss 16 and the through hole 22 by nuts 23. The movable center shaft 54 with the vacuum chamber 53 and the mounting boss 16 is fixed on the bearing seat flange 44 through the center shaft flange 45 and the flange hole 6 by bolts 2, and the vacuum sensor 18 is screwed into the vacuum chamber 53 through the mounting screw hole 17 and is locked by the screw cap 23. The lower end of the tension sensor 15 is fixed with the upper end of the movable center shaft 54 through the installation screw hole 17 by the bolt 2, and the upper end of the tension sensor 15 is fixed with the telescopic rod 14 of the servo electric cylinder 13 by the bolt 2. The servo electric cylinder 13 is fixed below the cross beam 12 by bolts 2, two ends of the cross beam 12 are fixed on the L-shaped plates 9, and the 2L-shaped plates 9 are respectively fixed at the upper end of the air supplementing chamber 1 by bolts 2.

The annular cavity pressure sensor 21 is fixed on the split annular cavity cover 7 with the arc-shaped air deflector 8 arranged below through the through hole 22 by using the screw cap 23, the sealing belt 51 is filled in the split sealing table 24 on the split annular cavity cover 7, then the symmetrical inlet pipe 49 of the split annular cavity cover 7 is fixed on the split annular cavity 4, the split annular cavity cover 7 with the arc-shaped air deflector 50 and the split sealing table 24 fixed on the other split is fixed on the split annular cavity 4 on the side with the inlet pipe 49, and the central lines of the arc-shaped air deflector 50 and the arc-shaped air deflector 8 are overlapped with the X axis. The servo motor cylinder 13, the tension sensor 15, the vacuum sensor 18, the annular cavity pressure sensor 21 and the air velocity sensor 60 are all connected with a control module unit 58 with a power cable 56 and a command cable 57 through signal lines 19, and screw joints 20 are arranged on the signal lines 19 of the tension sensor 15 and the vacuum sensor 18. The cover plate 10 is fixed on the mounting opening 11 of the air supplementing chamber 1 through the flange holes 6 and the flange screw holes 55 by bolts 2. And (5) finishing implementation.

Claims

1. An intelligent constant-vacuum mixed-flow water turbine generator set full-load range central operation air supplementing device is characterized in that an air blocking pipe with an upper hole and an arc sealing ring is fixed at the central position below a conical valve disc with a valve disc central hole in a sealing mode, floating balls are placed at the lower end of the inner part of the air blocking pipe through 4 support plates and supporting rings, the 4 support plates are fixed at the lower end of the inner part of the air blocking pipe, a valve disc seat with a conical valve port and the conical valve disc are concentrically fixed on the air supplementing cavity flange of the air supplementing cavity through flange holes, an air supplementing cavity flange and bolts, a central air supplementing pipeline is fixed below the air supplementing cavity, the central air supplementing pipeline is communicated with a mixed-flow water turbine vacuum area, an outer belt shaft table, pipe threads and a hollow rotating shaft with an adjusting shaft central hole inside are fixed at the central position above the conical valve disc through the flange holes on a base flange, the bearing seat with aligning hole below and with fish eye bearing and outer sleeve inside is set over the hollow shaft, the inner sleeve is set over the hollow shaft and is propped against the fish eye bearing, the outer sleeve of the fish eye bearing is sealed to the inner surface of the bearing seat, the inner sleeve of the fish eye bearing is assembled with the hollow shaft, the inner sleeve and the outer sleeve of the fish eye bearing slide in spherical sealing mode, the inner sleeve is fixed via the central nut via pipe thread, the wind distributing ring cavity with rubber sealing ring fixed onto the lower outlet pipe is fixed inside the air compensating chamber via 3U-shaped boards and bolts with the conic valve port as center, the rubber sealing ring is in sliding contact with the upper surface of the valve disc seat, the lower end of the movable middle shaft with vacuum cavity is fixed onto the bearing seat flange on the bearing seat via the middle shaft flange, flange hole and bolt, the connecting flange for the inlet pipe is communicated with the air compensating pipe via installing boss, the air speed sensor is arranged in the air supplementing pipe through the through hole and the screw cap; the annular cavity pressure sensor is fixed on a split annular cavity cover with an arc-shaped air deflector through a through hole by a screw cap, the split annular cavity cover is provided with a split sealing table, the split sealing table is provided with a split guide hole and a sealing belt, the split annular cavity cover with the arc-shaped air deflector is fixed on a split annular cavity opposite to an inlet pipe, the split annular cavity cover with the arc-shaped air deflector is symmetrical, the other split annular cavity cover with the arc-shaped air deflector is fixed on the split annular cavity with one side of the inlet pipe, and the center lines of the arc-shaped air deflector and the arc-shaped air deflector are both overlapped with an X axis; the front end of the vacuum sensor is screwed into the vacuum cavity through a mounting screw hole on the mounting boss, and then is fixed by a screw cap; the movable center shaft is connected with a telescopic rod of a servo electric cylinder through a tension sensor through bolts, the servo electric cylinder is fixed below a cross beam through bolts, two ends of the cross beam are respectively fixed on 2L-shaped plates, and the 2L-shaped plates are respectively fixed on the inner side of the air supplementing chamber through bolts; the servo electric cylinder, the vacuum sensor, the annular cavity pressure sensor and the air speed sensor are connected with a control module unit with a power cable and an instruction cable through signal wires, screw joints are arranged on the signal wires of the tension sensor and the vacuum sensor, the adjusting shaft middle hole is communicated with the vacuum cavity on the movable middle shaft through a communicating cavity, and the cover plate is fixed on the mounting opening of the air supplementing chamber through a flange hole and a flange screw hole through bolts.