CN211038892U

CN211038892U - Pressure relief and drainage device for top cover of horizontal mixed-flow water turbine

Info

Publication number: CN211038892U
Application number: CN201922022615.5U
Authority: CN
Inventors: 沈宏亮; 程抱贵; 姚远
Original assignee: Datang Diqing Shangri La Electric Power Dev Co ltd
Current assignee: Datang Diqing Shangri La Electric Power Dev Co ltd
Priority date: 2019-11-21
Filing date: 2019-11-21
Publication date: 2020-07-17
Anticipated expiration: 2029-11-21

Abstract

The utility model discloses a horizontal mixed-flow water turbine top cover pressure relief and drainage device, which comprises a pressure relief pipe, a connecting pipe, a pressure gauge, a flange and a sealing gasket; a pressure relief hole is formed in the top cover of the water turbine; the pressure relief pipe is provided with a water pressure detection device; the water inlet end of the pressure relief pipe is provided with a flange I, and the water outlet end of the pressure relief pipe is provided with a flange II; the flange I is connected with the pressure relief hole through a bolt, and a sealing gasket is arranged between the flange I and the pressure relief hole; the pressure relief pipe is provided with a valve II; the water pressure detection device comprises a connecting pipe, a valve I and a pressure gauge; a valve I is arranged on the connecting pipe; and a pressure gauge is arranged at the top end of the connecting pipe. The device of the utility model is simple in structure, the dismouting is freely, and it is convenient to overhaul the maintenance, and the effectual hydraulic turbine mainshaft seal that has avoided leaks gets into the guide bearing and arouses the rotten problem that accelerates deterioration of bearing lubricating oil and thrust tile temperature rise are high.

Description

Pressure relief and drainage device for top cover of horizontal mixed-flow water turbine

Technical Field

The utility model belongs to hydraulic turbine decompression drainage art field, concretely relates to horizontal mixed-flow hydraulic turbine top cap pressure release drainage device.

Background

In the actual operation of the water turbine generator set, the leakage of the main shaft seal easily causes pressure water to flow into a water guide bearing of the water turbine along the axial direction, so that the lubricating oil of the bearing is deteriorated, the deterioration is accelerated, and the temperature of a water guide bearing bush of the generator set is increased to reduce the load for operation. Meanwhile, the gap between the runner crown and the water turbine top cover can increase year by year along with the high-speed running cavitation of the runner, so that the pressure of a cavity between the runner crown and the water turbine top cover is increased, but the drainage capacity of the pressure relief hole of the runner is certain, so that water which cannot be drained in the crown cavity of the runner cannot be effectively drained to tail water or a water collecting well, pressure water cannot be quickly drained or completely relieved, water pressure presses on the crown to generate axial water thrust towards the direction of a tail water pipe of the water turbine, the thrust bearing stress of the water turbine is increased rapidly by the axial water thrust, and the crown of the runner is unbalanced in stress to cause vibration, thereby causing the rubber sealing element to be worn seriously, increasing the maintenance times of the machine set for replacing the main shaft sealing element when the machine set is stopped, meanwhile, the front and rear guide bearings of the hydraulic generator can bear unbalanced vibration force of the unit, so that the temperatures of the thrust bearing and the front and rear guide bearings are increased, and the load of the unit is reduced. On the other hand, the main shaft leaks water and is connected with the hydraulic guide bearing of the hydraulic generator in series and can be mixed with turbine oil, so that the lubricating effect of the turbine oil is reduced, the friction coefficient of the thrust bush and the mirror plate is increased, the temperature rise and the load reduction operation of the thrust bush are easily caused, and the normal operation of the hydraulic generator set is influenced.

At present, when the spindle sealing water leakage and the reduction of the stress of the thrust tile and the reduction of the tile temperature are carried out on the horizontal mixed-flow water turbine, the spindle sealing element needs to be detached, the sealing element is replaced again, the stress of the thrust tile is adjusted or scraped, the effects of reducing the spindle sealing water leakage and the reduction of the thrust tile temperature can be achieved, a large amount of manpower and material resources are needed in the process, meanwhile, the spindle sealing element needs to be replaced and maintained every time of water leakage, and the overhauling cost is improved.

SUMMERY OF THE UTILITY MODEL

To prior art because of horizontal mixed flow hydraulic turbine main shaft seal leaks and arouses the unit to reduce the load operation, and the number of times that needs the unit to shut down and overhaul increases, spends a large amount of manpower and materials, problem with too high costs, the utility model provides a horizontal mixed flow hydraulic turbine top cap pressure release drainage device.

The utility model discloses a realized through following technical scheme:

a pressure relief and drainage device for a top cover of a horizontal mixed-flow water turbine is arranged on the top cover of the water turbine and comprises a pressure relief pipe, a connecting pipe and a pressure gauge; the top cover of the water turbine is provided with a pressure relief hole, and the pressure relief hole is connected with a pressure relief pipe through a flange I; a sealing gasket is arranged between the pressure relief hole and the flange I; the other end of the pressure relief pipe, which is far away from the flange I, is provided with a flange II, the flange II is connected with a tail water pipe, and a pressure gauge and a ball valve are sequentially arranged on the pipe body of the pressure relief pipe; the pressure gauge is communicated with the pressure relief pipe through a connecting pipe; the ball valve is arranged on the pressure relief pipe body between the flange II and the pressure gauge.

The measuring range of the pressure gauge is set according to the rated water head of the water turbine; the pressure gauge measures the leakage pressure of the water turbine top cover through a switch ball valve. And closing the ball valve, namely testing pressure, opening the ball valve, discharging the pressure water, and making the data of the pressure gauge unavailable.

The utility model discloses an installation drainage device on the hydraulic turbine top cap, can effectually with the effectual row of partial pressure water to draft tube or sump pit of cavity between runner crown and the hydraulic turbine top cap, the effectual axial pressure and the runner that has reduced because of top cap pressure water turn to unbalanced force and cause the problem that water guide shaft and thrust bearing tile temperature rose to reached the ageing wearing and tearing that reduce main shaft sealing member and reduced water guide tile and the high problem of thrust bearing tile temperature, thereby guaranteed the long period end load steady operation of unit.

In order to ensure that the main shaft of the water turbine effectively rotates, a certain gap exists between the part of the main shaft of the water turbine, which is positioned in the top cover, and the top cover, the gap is called as a water turbine crown, the width of the gap is generally about 0.01mm, the cavitation quantity is gradually increased along with the high-speed operation of the main shaft, and the gap cavity is also increased, so that a gap cavity is formed, the pressure of the gap cavity is increased, so that the load operation of the water turbine is reduced, when pressure water leaks into the gap cavity from the main shaft, because the pressure relief capacity of the rotating wheel is certain, the pressure water cannot be effectively discharged, the water pressure is pressed on the rotating wheel crown, an axial water thrust force towards the tail water pipe direction of the water turbine is generated, the thrust bearing force of the water turbine is increased rapidly by the axial water thrust force, the rotating wheel crown is unbalanced in stress, so that vibration is caused, further, meanwhile, the front and rear guide bearings of the hydraulic generator can bear unbalanced vibration force of the unit, so that the temperatures of the thrust bearing and the front and rear guide bearings are increased, and the load of the unit is reduced.

As a further improvement of the utility model, the pressure relief hole is arranged at any position on the top cover of the water turbine; the sectional area of the pressure relief hole is larger than or equal to the gap area between the runner crown and the hydraulic turbine top cover.

As a further improvement, the sectional area of the pressure relief hole is larger than or equal to the size of the clearance area between the runner crown and the hydraulic turbine top cover.

The pressure release hole can be installed at the optional position of hydraulic turbine top cap, the mounted position does not influence sluicing pressure discharge effect, because the pressure release ratio of pressure water is the fixed value, for and reach best pressure discharge effect, the sectional area of pressure release hole will be more than or equal to runner upper crown to the clearance area of top cap, this clearance area can be approximately equated to the top cap sectional area and subtract the clearance width after the runner sectional area again, because the clearance width between runner upper crown and the top cap is about 0.01mm, consequently can be approximately equated to the top cap sectional area and subtract the runner sectional area, this value is very little, consequently, the pressure release hole can be according to the pipeline setting on the market, its sectional area all can be big than this value.

And simultaneously, the utility model also provides a horizontal mixed-flow water turbine top cap pressure release drainage device's application method, including following step:

(1) water pressure measurement: closing the ball valve, generating water pressure in the pressure relief pipe, and reading a reading on a pressure gauge after the water pressure is stable to obtain the pressure of the top cover and the cavity of the upper crown of the rotating wheel;

(2) draining and decompressing: opening the flange II, and adjusting the drainage flow through a ball valve to discharge the drainage water from the pressure relief pipe;

(3) and (5) ending pressure relief: and (4) closing the ball valve and then closing the flange II.

The utility model has the advantages that:

1. the utility model discloses simple structure, the dismouting is freely, and it is convenient to overhaul the maintenance, can effectively release the pressure of unit top cap and runner crown cavity and eliminate the unbalanced vibration and vibration that arouse of runner crown atress and lead to a great deal of problems such as main shaft rubber seal wearing and tearing to reduce the unit and shut down the maintenance number of times.

2. The utility model discloses can with the effectual row of partial pressure water of cavity to draft tube or sump pit between runner crown and the hydraulic turbine top cap, reduce the water leakage of main shaft water seal, ensured hydraulic turbine water guide bearing can not appear intaking and cause the oil quality degradation and the high problem of tile temperature appears.

3. The utility model discloses avoided leaking and cluster into hydraulic turbine water guide bearing oil tank for turbine oil lubrication water inlet deterioration results in thrust tile and runner plate coefficient of friction increase, thereby makes thrust tile temperature rise lead to the problem that the unit shut down the operation.

4. Installation the utility model discloses afterwards, improved horizontal mixed flow rivers generating set's operating efficiency, reduced the maintenance number of times to the unit to make the factor of safety and the benefit of power station obtain great improvement.

Drawings

Fig. 1 is a schematic structural view of the drainage device of the present invention.

Fig. 2 is a top view of the drainage device of the present invention.

Fig. 3 is a schematic structural view of the pressure relief pipe of the present invention.

Reference numerals: 1-water turbine top cover, 2-pressure relief pipe, 3-connecting pipe, 4-flange II, 5-pressure gauge, 6-pressure relief hole, 7-flange I, 8-sealing gasket, 9-runner crown, 10-ball valve, 11-water turbine inlet pipe and 12-clearance cavity.

Detailed Description

The present invention will be further explained with reference to the accompanying drawings.

Example 1

As shown in fig. 1 and 2, the pressure relief and drainage device for the top cover of the horizontal mixed-flow water turbine is arranged on the top cover 1 of the water turbine and comprises a pressure relief pipe 2, a connecting pipe 3 and a pressure gauge 5, when pressure water enters the water turbine from a water inlet pipe 11 of the water turbine to turn to generate power, part of the pressure water may enter a gap cavity between a runner crown 9 and the top cover 1 due to leakage of a main shaft.

The device of the embodiment is arranged on the water turbine top cover 1, the water turbine top cover 1 is provided with the pressure relief holes 6, the pressure relief holes 6 are arranged at any position of the end surface of the water turbine top cover 1, the pressure relief holes can be arranged at positions which are convenient to maintain according to the design of a water turbine, and the optimal pressure relief effect can be achieved only when the sectional areas of the pressure relief pipes 2 and the pressure relief holes 6 are larger than or equal to the gap area between the upper crown of the runner 9 and the water turbine top cover 1; the pressure relief hole 6 is connected with the pressure relief pipe 2 through a flange I7, and the flange I7 is welded with the pressure relief pipe 2; and a sealing gasket 8 is arranged between the pressure relief hole 6 and the flange I7.

The pressure relief pipe 2 is shown in fig. 3, and after the gap area between the crown and the top cover of the runner is calculated, the pressure relief pipe 2 adopts a DN32 pipe; the other end that flange I7 was kept away from to pressure release pipe 2 is equipped with flange II 4, and flange II 4 is connected with the draft tube to be equipped with manometer 5 and ball valve 10 on pressure release pipe 2's the body in proper order, ball valve 10 sets up on pressure release pipe 2 body between flange II 4 and manometer 5. The diameter of the pressure relief pipe 2 is as large as that of the pressure relief hole 6, and the pressure relief pipe 2 is a seamless pipe. The pressure gauge 5 is communicated with the pressure relief pipe 2 through a connecting pipe 3, the measuring range of the pressure gauge is set according to the rated water head of the water turbine, and the leakage pressure of the water turbine top cover 1 is measured through the switch ball valve 10.

Before the drainage device of the embodiment is used, firstly, the size of a pressure relief hole 6 is set according to the gap area between the crown of a water turbine runner 9 and a water turbine top cover 1, and the diameter of a pressure relief pipe 2 is selected to determine the total pressure relief area, then, the pressure relief drainage device is manufactured according to the actual situation, and finally, the pressure relief drainage device can be put into use by being directly installed on the water turbine top cover 1;

the use method of the pressure relief and drainage device for the top cover of the horizontal mixed-flow water turbine comprises the following steps:

(1) water pressure measurement: closing the ball valve 10, generating water pressure in the pressure relief pipe 2, and reading the reading on the pressure gauge 5 after the water pressure is stable to obtain the pressure of the top cover and the upper crown cavity of the rotating wheel;

(2) draining and decompressing: opening the flange II 4, and adjusting the drainage flow through the ball valve 10 to discharge the drainage water from the pressure relief pipe 2;

(3) and (5) ending pressure relief: firstly, closing the ball valve 10, and then closing the flange II 4.

Example 2

Compared with the embodiment, the present embodiment is different in that: the pressure relief pipe 2 adopts DN25 pipe.

The above embodiments are only exemplary embodiments of the present invention, and are not intended to limit the present invention, and the protection scope of the present invention is defined by the claims. Various modifications and equivalents of the invention may be made by those skilled in the art within the spirit and scope of the invention, and such modifications and equivalents should also be considered as falling within the scope of the invention.

Claims

1. The utility model provides a horizontal mixed-flow water turbine top cap pressure release drainage device, sets up on hydraulic turbine top cap (1), its characterized in that: comprises a pressure relief pipe (2), a connecting pipe (3) and a pressure gauge (5);

the hydraulic turbine top cover (1) is provided with a pressure relief hole (6), and the pressure relief hole (6) is connected with the pressure relief pipe (2) through a flange I (7); a sealing gasket (8) is arranged between the pressure relief hole (6) and the flange I (7);

the other end of the pressure relief pipe (2), which is far away from the flange I (7), is provided with a flange II (4), and a pressure gauge (5) and a ball valve (10) are sequentially arranged on the pipe body of the pressure relief pipe (2);

the pressure gauge (5) is communicated with the pressure relief pipe (2) through a connecting pipe (3);

the ball valve (10) is arranged on a pressure relief pipe (2) body between the flange II (4) and the pressure gauge (5).

2. The pressure relief and drainage device for the top cover of the horizontal mixed-flow water turbine as claimed in claim 1, is characterized in that: the pressure relief hole (6) is arranged at any position on the water turbine top cover (1).

3. The pressure relief and drainage device for the top cover of the horizontal mixed-flow water turbine as claimed in claim 2, is characterized in that: the sectional area of the pressure relief hole (6) is larger than or equal to the size of the gap area between the upper crown of the runner (9) and the water turbine top cover (1).