Novel steam turbine sealing device

Abstract

The utility model discloses a novel steam turbine sealing device, which relates to the field of steam turbines, and comprises a shell, a rotor is arranged in the shell, the outer end of the rotor is connected with a sealing ring, the inner wall of the shell is provided with a moving ring, and the moving ring is connected with a sealing ring. A small backflow groove and a large backflow groove are formed in the inner wall of the movable ring, the small backflow groove and the large backflow groove are the same in structure, and a flow guide ring is connected into the small backflow groove and the large backflow groove. By arranging the small backflow groove and the large backflow groove, when gas passes through the small backflow groove, part of the gas is blocked by the small baffle, the gas is shunted, part of the gas reversely moves through the small backflow groove, and therefore part of follow-up gas is blocked from entering, and similarly, when the gas enters the large backflow groove, the follow-up gas can also be blocked; therefore, the amount of gas entering the ventilating duct is reduced, the gas circulation amount of a gap between the rotor and the shell can be effectively reduced, and the sealing effect of the device can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of steam turbines, in particular to a novel steam turbine sealing device. Background Art

[0002] A steam turbine, also known as a steam turbine engine, is a rotary steam-powered device. Its working principle is mainly to use high-temperature and high-pressure steam to drive a rotor equipped with rows of blades to rotate, thereby performing external work. It can convert the thermal energy of steam into mechanical energy. It is the main equipment of modern thermal power plants and is also widely used in the metallurgical industry, chemical industry, ship power units and other fields.

[0003] The rotor rotates at high speed inside the turbine. In order to avoid friction between the rotor and the inner wall of the turbine casing, which may cause wear and damage to the rotor, a certain gap is left between the rotor and the turbine casing. In order to reduce and prevent gas from passing through the rotor through the gap, a sealing device needs to be installed in the gap.

[0004] The labyrinth comb seal changes the gas pressure through the flow channel structure, causing the gas to experience multiple pressure changes when passing through the sealing gap, thereby reducing gas leakage. Due to its advantages such as simple structure, high reliability, and relatively low maintenance cost, it is widely used in turbine seals. However, the labyrinth comb seal still has some problems when used: when starting the rotor or adjusting the rotor speed, the rotor will vibrate, causing the rotor to collide and rub against the long teeth of the labyrinth comb, which may cause wear on the long teeth of the labyrinth comb, thereby affecting its service life.

[0005] In order to solve this technical problem, the utility model proposes a novel steam turbine sealing device. Utility Model Content

[0006] The main purpose of the utility model is to provide a novel steam turbine sealing device, which can effectively solve the problems mentioned in the background technology.

[0007] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0008] A new type of steam turbine sealing device includes an outer shell, a rotor is arranged in the outer shell, a sealing ring is connected to the outer end of the rotor, a movable ring is provided on the inner wall of the outer shell, a small reflow groove and a large reflow groove are opened on the inner wall of the movable ring, the small reflow groove has the same structure as the large reflow groove, a guide ring is connected inside the small reflow groove, a ventilation duct is formed between the movable ring and the sealing ring, a small baffle and a large baffle are provided between the small reflow groove and the large reflow groove, a raised ring is connected to the outer end of the sealing ring, and a concave groove is provided on the side end of the raised ring.

[0009] Preferably, the small reflux grooves and the large reflux grooves are staggered, and the small reflux grooves and the large reflux grooves are inclined, and their shapes are the same as the channel shape in the "Tesla one-way valve".

[0010] Preferably, the guide ring and the movable ring are connected by a thin connecting rod, the ventilation duct is connected to the small reflow groove and the large reflow groove, the small baffle is located at the front end of the raised ring, and the large baffle is located at the rear end of the raised ring.

[0011] Preferably, the movable ring is located at the outer end of the sealing ring, the raised ring is located at the side end of the large reflux groove, and the gap between the raised ring and the small baffle is larger than the gap between the raised ring and the large baffle.

[0012] Preferably, a pressurized air channel is opened in the shell, the movable ring can be stretched, and an elastic connecting ring is connected between the pressurized air channel and the movable ring, and the elastic connecting ring is particularly elastic.

[0013] Preferably, a connecting airway is opened in the shell, the connecting airway is connected to the pressurized airway, the outer end of the connecting airway is connected to a ventilation pipe, the side end of the ventilation pipe is connected to a branch pipe, and the upper end of the branch pipe is connected to an air pressure detection gauge.

[0014] Preferably, the upper end of the ventilation pipe is connected to a pressurizing pipe and a pressure relief pipe respectively, and a one-way electric valve is connected between the pressurizing pipe, the pressure relief pipe and the ventilation pipe respectively.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] In the utility model, a small reflux groove and a large reflux groove are provided. When the gas enters the large reflux groove from the lower end of the small baffle, the space suddenly becomes larger, the gas will expand, the pressure decreases, and the gas passes through multiple small baffles in turn, and the pressure continues to decrease, thereby achieving the purpose of sealing (the principle of labyrinth comb seal). When the gas passes through the small reflux groove, part of the gas is blocked by the small baffle, the gas is diverted, and part of the gas moves in the opposite direction through the small reflux groove, thereby hindering the entry of subsequent gas. Similarly, when the gas enters the large reflux groove, it can also block the subsequent gas, thereby reducing the amount of gas entering the ventilation duct. With this device, it can effectively reduce the gas flow in the gap between the rotor and the casing, thereby improving its sealing effect.

[0017] In the utility model, a pressurized air duct and an elastic connecting ring are provided, and by opening the one-way electric valve at the lower end of the pressurized pipe, gas can be injected into the pressurized air duct through the vent pipe to increase the pressure, so that the elastic connecting ring can be squeezed and expanded by the gas, thereby pushing the moving ring, and the sealing can be completed at this time. When the one-way electric valve at the lower end of the pressure relief pipe is opened, the gas in the pressurized air duct will enter the pressure relief pipe, thereby completing the pressure relief. At this time, the elastic connecting ring will pull the moving ring away from the sealing ring by relying on its own elastic contraction, so that the sealing ring at its outer end can avoid contact, friction and collision with the moving ring when the rotor vibrates, thereby effectively protecting the moving ring and the sealing ring, thereby extending the service life of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the overall structure of a new type of steam turbine sealing device of the utility model;

[0019] Figure 2 This is a schematic diagram of the side structure of a new type of steam turbine sealing device of the utility model;

[0020] Figure 3 This is a schematic diagram of the rotor structure of a new type of steam turbine sealing device of the utility model;

[0021] Figure 4 This is a schematic diagram of the cross-sectional structure of a moving ring of a new steam turbine sealing device of the present utility model;

[0022] Figure 5 This is a schematic structural diagram of the small reflux groove and the large reflux groove of a new type of steam turbine sealing device of the utility model.

[0023] In the figure: 1. Housing; 2. Rotor; 3. Sealing ring; 4. Moving ring; 5. Small reflux groove; 6. Large reflux groove; 7. Guide ring; 8. Ventilation duct; 9. Small baffle; 10. Large baffle; 11. Raised ring; 12. Concave groove; 13. Pressurized air duct; 14. Elastic connecting ring; 15. Connecting air duct; 16. Ventilation pipe; 17. Air pressure detection gauge; 18. Pressurized pipe; 19. Pressure relief pipe; 20. One-way electric valve. DETAILED DESCRIPTION

[0024] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific implementation methods.

[0025] like Figure 1-5As shown, a new type of steam turbine sealing device includes a shell 1, a rotor 2 is arranged in the shell 1, and the rotor 2 consists of a rotating shaft and blades. When the gas passes through the surface of the blades, the thrust generated will be able to drive the rotating shaft to rotate. The outer end of the rotor 2 is connected to a sealing ring 3, and the inner wall of the shell 1 is provided with a movable ring 4, which is located at the outer end of the sealing ring 3.

[0026] The inner wall of the mobile ring 4 is provided with a small reflux groove 5 and a large reflux groove 6. The small reflux groove 5 and the large reflux groove 6 are arranged alternately. The gap between the small reflux groove 5 and the large reflux groove 6 is different from the gap between the two and the sealing ring 3. When the gas enters the large reflux groove 6 from the small reflux groove 5, the gas pressure will be able to change. The small reflux groove 5 has the same structure as the large reflux groove 6. A guide ring 7 is connected to the inside thereof. The guide ring 7 is connected to the mobile ring 4 by a small connecting rod, so that the guide ring 7 can be fixed. The small reflux groove 5 and the large reflux groove 6 are all inclined, and their shape is the same as the channel shape in the "Tesla one-way valve". The gas entering the small reflux groove 5 and the large reflux groove 6 will be able to be moved in the opposite direction. A ventilation duct 8 is formed between the movable ring 4 and the sealing ring 3. The ventilation duct 8 is connected with the small reflux groove 5 and the large reflux groove 6. A small baffle 9 and a large baffle 10 are provided between the small reflux groove 5 and the large reflux groove 6. The small baffle 9 is used to divert part of the gas into the small reflux groove 5, and the large baffle 10 is used to divert part of the gas into the large reflux groove 6.

[0027] The outer end of the sealing ring 3 is connected to a raised ring 11, the small baffle 9 is located at the front end of the raised ring 11, and the large baffle 10 is located at the rear end of the raised ring 11. A concave groove 12 is provided at the side end of the raised ring 11. The concave groove 12 guides part of the gas in the opposite direction through the arc surface to block part of the gas. The gap between the raised ring 11 and the small baffle 9 is larger than the gap between the raised ring 11 and the large baffle 10.

[0028] A pressurized air channel 13 is provided in the outer shell 1, and the movable ring 4 can be stretched. An elastic connecting ring 14 is connected between the pressurized air channel 13 and the movable ring 4. The elastic connecting ring 14 is particularly elastic. When the pressurized air channel 13 is injected with gas, the gas will be able to expand the elastic connecting ring 14, thereby pushing the movable ring 4. A connecting air channel 15 is provided in the outer shell 1, and the connecting air channel 15 is connected to the pressurized air channel 13. The outer end of the connecting air channel 15 is connected to a vent pipe 16, and the side end of the vent pipe 16 is connected to a branch pipe. The upper end of the branch pipe is connected to an air pressure detection gauge 17, and the air pressure detection gauge 17 is used to detect the air pressure in the pressurized air channel 13.

[0029] The upper end of the vent pipe 16 is connected to a pressurizing pipe 18 and a pressure relief pipe 19 respectively. There is high-pressure gas in the pressurizing pipe 18. A one-way electric valve 20 is connected between the pressurizing pipe 18, the pressure relief pipe 19 and the vent pipe 16 respectively. The one-way electric valve 20 is used to prevent the gas from moving in the opposite direction. When the one-way electric valve 20 at the lower end of the pressurizing pipe 18 is opened, the high-pressure gas in the pressurizing pipe 18 will enter the pressurizing airway 13 through the vent pipe 16 and the connecting airway 15, thereby pressurizing the pressurizing airway 13. In this way, the gas is used to push the elastic connecting ring 14 to push the moving ring 4. When the one-way electric valve 20 at the lower end of the pressure relief pipe 19 is opened, the high-pressure gas in the pressurizing airway 13 will enter the pressure relief pipe 19 through the connecting airway 15 and the vent pipe 16. At this time, the pressure in the pressurizing airway 13 is reduced, and the elastic connecting ring 14 relies on its own elastic contraction to drive the moving ring 4 away from the sealing ring 3.

[0030] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements are intended to fall within the scope of the present invention. The scope of protection claimed in this invention is defined by the appended claims and their equivalents.

Claims

1. A novel steam turbine sealing device, comprising a housing (1), characterized in that: A rotor (2) is provided in the housing (1), and a sealing ring (3) is connected to the outer end of the rotor (2). A moving ring (4) is provided on the inner wall of the housing (1), and a small reflux groove (5) and a large reflux groove (6) are provided on the inner wall of the moving ring (4). The small reflux groove (5) has the same structure as the large reflux groove (6), and a guide ring (7) is connected to the inside thereof. A ventilation duct (8) is formed between the moving ring (4) and the sealing ring (3), and a small baffle (9) and a large baffle (10) are provided between the small reflux groove (5) and the large reflux groove (6). The outer end of the sealing ring (3) is connected to a raised ring (11), and a concave groove (12) is provided on the side end of the raised ring (11).

2. A new steam turbine sealing device according to claim 1, characterized in that: The small reflux grooves (5) and the large reflux grooves (6) are arranged in a staggered manner. The small reflux grooves (5) and the large reflux grooves (6) are both arranged in an inclined manner, and their shapes are the same as the channel shape in the "Tesla one-way valve".

3. A new type of steam turbine sealing device according to claim 1, characterized in that: The guide ring (7) and the movable ring (4) are connected via a thin connecting rod, the ventilation duct (8) is connected to the small reflow groove (5) and the large reflow groove (6), the small baffle (9) is located at the front end of the raised ring (11), and the large baffle (10) is located at the rear end of the raised ring (11).

4. A new type of steam turbine sealing device according to claim 1, characterized in that: The movable ring (4) is located at the outer end of the sealing ring (3), the raised ring (11) is located at the side end of the large reflux groove (6), and the gap between the raised ring (11) and the small baffle (9) is larger than the gap between the raised ring (11) and the large baffle (10).

5. The novel steam turbine sealing device according to claim 1 is characterized in that: A pressurized air channel (13) is provided in the housing (1), the movable ring (4) can be stretched, and an elastic connecting ring (14) is connected between the pressurized air channel (13) and the movable ring (4), and the elastic connecting ring (14) is particularly elastic.

6. A new type of steam turbine sealing device according to claim 5, characterized in that: A connecting airway (15) is provided in the housing (1), the connecting airway (15) being in communication with the pressurized airway (13), the outer end of the connecting airway (15) being connected to a vent pipe (16), the side end of the vent pipe (16) being connected to a branch pipe, the upper end of the branch pipe being connected to an air pressure detection gauge (17).

7. A new steam turbine sealing device according to claim 6, characterized in that: The upper end of the vent pipe (16) is connected to a pressurizing pipe (18) and a pressure relief pipe (19), respectively. A one-way electric valve (20) is connected between the pressurizing pipe (18), the pressure relief pipe (19) and the vent pipe (16).

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