High-sealing-performance steam seal structure of steam turbine

Abstract

The utility model discloses a steam seal structure of a steam turbine with high sealing performance, which relates to the field of steam seal of steam turbines and comprises a steam seal shell and an air inlet chamber arranged on the upper portion of the steam seal shell. According to the utility model, through the pressure relief steam pipe arranged at the bottom of the steam seal shell, steam enters the steam seal shell through the air inlet chamber, one part of air steam is discharged from the air outlet chamber after circulating through the annular air inlet chamber in the steam seal shell, and when the internal pressure of the steam seal shell is too large, the other part of air steam enters from the pressure relief steam pipe; the internal circulation efficiency of the steam seal structure of the steam turbine is guaranteed, redundant steam is guided and exhausted, the internal pressure of the steam seal structure is effectively reduced, one-way closing of the opening and closing valve is guaranteed by means of the rotation principle of the torque spring, the steam is prevented from flowing back into the steam seal structure, and the steam seal structure is protected. And the leakproofness of the steam seal structure is improved.

Description

Technical Field

[0001] The utility model relates to the field of steam turbine steam seals, in particular to a steam turbine steam seal structure with high sealing performance. Background Art

[0002] The steam seal structure of a steam turbine is a sophisticated and complex system that needs to maintain stable sealing performance under high temperature, high pressure and high speed operating conditions. The design and manufacture of these structures and components must meet strict engineering standards to ensure the safe, reliable operation and high efficiency of the steam turbine.

[0003] The utility model patent with announcement number CN201460995U discloses that the utility model has a compact and simple structure, a reasonable design, is easy to install, and has a low overall cost. The use of this device can reduce the pressure drop of the working fluid on both sides of the single-row brush-type steam seal piece on the shaft brush steam seal, enhance the sealing effect, and greatly improve the stiffness and strength of the brush-type steam seal piece, making this device a high-pressure resistant and highly sealed shaft brush steam seal.

[0004] However, the existing steam seal structure of the steam turbine affects the airtightness of the internal structure when the steam pressure inside the seal structure is too high. Therefore, it is inconvenient to automatically guide and discharge excess steam according to the steam pressure inside the seal structure, which makes the internal pressure of the cylinder too high and reduces the airtightness inside the seal mechanism. While ensuring the internal steam circulation efficiency, the sealing performance of the seal mechanism is improved. Utility Model Content

[0005] The utility model provides a high-sealing steam turbine steam seal structure, which has the advantages of automatically guiding and discharging excess steam, so as to solve the problem of reducing the internal pressure of the steam seal structure to improve the sealing performance of the steam seal structure in the existing steam circulation process.

[0006] In order to achieve the purpose of improving the sealing performance of the steam seal structure by reducing the internal pressure of the steam seal structure, the utility model provides the following technical solutions: a high-sealing steam seal structure for a steam turbine, comprising a steam seal shell, an air inlet chamber arranged on the upper part of the steam seal shell, and a pressure relief steam pipe arranged at the bottom of the steam seal shell, the pressure relief steam pipe being assembled so that when steam enters the air inlet chamber, the pressure relief steam pipe will discharge the excess steam inside the steam seal shell separately, and also comprising: an air outlet chamber arranged at one end of the bottom of the steam seal shell, one end of the air outlet chamber being through-connected to one end of the pressure relief steam pipe; a transmission hub mechanism arranged inside the steam seal shell, the transmission hub mechanism comprising an axial hub, a roller shaft and a moving blade grid; a one-way ventilation pressure relief mechanism arranged on the pressure relief steam pipe, the one-way ventilation pressure relief mechanism comprising a one-way ventilation valve, a receiving door, a torque spring and an opening and closing valve; a stationary blade grid arranged inside the steam seal shell, the number of the stationary blade grids being several.

[0007] As a preferred technical solution of the utility model, both ends of the axial hub are fixedly connected with roller shafts, and the surface of the axial hub is provided with a moving blade cascade.

[0008] As a preferred technical solution of the utility model, there are several moving blade cascades, and the several moving blade cascades are evenly distributed on the surface of the axial hub in a straight line.

[0009] As a preferred technical solution of the utility model, both ends of the one-way vent valve are connected to the pressure relief steam pipe, and a receiving door is fixedly connected to the middle part of the one-way vent valve, and the surface of the receiving door is rotatably connected to an opening and closing valve through a torque spring.

[0010] As a preferred technical solution of the utility model, both ends of the surface of the one-way vent valve are connected to the pressure relief steam pipe through threaded bolts and threaded caps, and both ends of the one-way vent valve are fitted with sealing rubber rings.

[0011] As a preferred technical solution of the utility model, a plurality of the stationary blade cascades are evenly distributed in a straight line inside the steam seal housing, and the inner ends of adjacent stationary blade cascades are embedded with moving blade cascades.

[0012] As a preferred technical solution of the utility model, the surfaces of the rollers are rotatably connected to both ends of the steam seal housing, and the steam seal housing includes an upper shell and a lower shell, and the upper shell and the lower shell are seamlessly welded.

[0013] As a preferred technical solution of the utility model, the transmission hub mechanism is rotatably connected to the interior of the steam seal housing, and the transmission hub mechanism forms an annular air inlet chamber inside the steam seal housing.

[0014] Compared with the prior art, the utility model provides a high-sealing steam turbine steam seal structure, which has the following beneficial effects:

[0015] The steam seal structure of the steam turbine with high sealing performance is characterized in that the steam enters the interior of the steam seal shell through the pressure relief steam pipe arranged at the bottom of the steam seal shell, and a part of the steam circulates through the internal annular air inlet chamber of the steam seal shell and is discharged from the air outlet chamber. When the internal pressure of the steam seal shell is too high, another part of the steam enters through the pressure relief steam pipe and is discharged to the air outlet chamber through the one-way ventilation and pressure relief mechanism, thereby ensuring the internal circulation efficiency of the steam seal structure of the steam turbine and guiding and discharging the excess steam, effectively reducing the internal pressure of the steam seal structure. The rotation principle of the torque spring is utilized to ensure the one-way closing of the opening and closing valve, thereby preventing the steam from flowing back into the interior of the steam seal structure and improving the sealing performance of the steam seal structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0017] Figure 2 This is a schematic diagram of the internal structure of the steam seal housing of the utility model;

[0018] Figure 3 This is a schematic diagram of the disassembled structure of the pressure relief steam pipe and the one-way ventilation pressure relief mechanism of the utility model;

[0019] Figure 4 It is an overall plan view of the utility model.

[0020] In the figure: 1. steam seal housing; 101. upper shell; 102. lower shell; 2. air inlet chamber; 3. pressure relief steam pipe; 4. air outlet chamber; 5. transmission hub mechanism; 501. axial hub; 502. roller shaft; 503. moving blade grid; 6. one-way ventilation pressure relief mechanism; 601. one-way ventilation valve; 602. receiving door; 603. torque spring; 604. opening and closing valve; 7. stationary blade grid; 8. threaded bolt; 9. threaded cap; 10. sealing rubber ring; 11. annular air inlet chamber. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0022] See also Figure 1-Figure 4 The utility model discloses a steam seal structure for a steam turbine with high sealing performance, a steam seal structure for a steam turbine with high sealing performance, comprising a steam seal shell 1, an air inlet chamber 2 arranged at the upper part of the steam seal shell 1, and a pressure relief steam pipe 3 arranged at the bottom of the steam seal shell 1, the pressure relief steam pipe 3 being arranged so that when steam enters the air inlet chamber 2, the pressure relief steam pipe 3 discharges excess steam from the steam seal shell 1 separately, and further comprising: an air outlet chamber 4 arranged at one end of the bottom of the steam seal shell 1, one end of the air outlet chamber 4 being through-connected to one end of the pressure relief steam pipe 3; a transmission hub mechanism 5 arranged inside the steam seal shell 1, the transmission hub mechanism 5 comprising an axial hub 501, a roller shaft 502 and a moving blade grid 503; a one-way ventilation pressure relief mechanism 6 arranged on the pressure relief steam pipe 3, the one-way ventilation pressure relief mechanism 6 comprising a one-way ventilation valve 601, a receiving door 602, a torque spring 603 and an opening and closing valve 604; a stationary blade grid 7 arranged inside the steam seal shell 1, and the number of the stationary blade grid 7 is several.

[0023] Specifically, roller shafts 502 are fixedly connected to both ends of the axial hub 501, and a moving blade cascade 503 is provided on the surface of the axial hub 501;

[0024] There are a plurality of moving blade cascades 503 , and the plurality of moving blade cascades 503 are evenly distributed on the surface of the axial hub 501 in a straight line.

[0025] In this embodiment, as steam enters the steam seal housing 1 and circulates, the axial hub 501 drives the rollers 502 and the moving blade cascades 503 at both ends to rotate inside the steam seal housing 1 .

[0026] Specifically, both ends of the one-way vent valve 601 are connected to the pressure relief steam pipe 3, and a receiving door 602 is fixedly connected to the middle of the one-way vent valve 601. The surface of the receiving door 602 is rotatably connected to an opening and closing valve 604 through a torque spring 603;

[0027] Both ends of the surface of the one-way vent valve 601 are connected to the pressure relief steam pipe 3 through threaded bolts 8 and threaded caps 9, and both ends of the one-way vent valve 601 are fitted with sealing rubber rings 10.

[0028] In this embodiment, when the steam pressure is too high, the steam enters from the pressure relief steam pipe 3 at the bottom of the steam seal shell 1, and when passing through the one-way vent valve 601, it pushes the on-off valve 604 to open, so that the pressure relief steam pipe 3 is connected to the air outlet chamber 4 to discharge excess steam. When no steam enters, the on-off valve 604 automatically closes under the action of the torque spring 603 to prevent steam backflow. The threaded bolt 8 and threaded cap 9 provided on the one-way vent valve 601 facilitate fixing the one-way vent pressure relief mechanism 6 on the pressure relief steam pipe 3. At the same time, sealing rubber rings 10 are added to both ends of the one-way vent valve 601 to improve the sealing performance during exhaust.

[0029] Specifically, a plurality of stationary blade cascades 7 are evenly distributed in a straight line inside the steam seal housing 1 , and the inner ends of adjacent stationary blade cascades 7 are embedded with moving blade cascades 503 .

[0030] In this embodiment, the stationary blade grid 7 and the moving blade grid 503 are arranged inside the steam seal housing 1. The stationary blade grid 7 is mainly responsible for guiding and optimizing the flow of steam, while the moving blade grid 503 converts the kinetic energy of the steam into mechanical energy to drive the transmission hub mechanism 5 to rotate.

[0031] Specifically, the surfaces of the roller shaft 502 are rotatably connected to both ends of the steam seal housing 1 , and the steam seal housing 1 includes an upper shell 101 and a lower shell 102 , and the upper shell 101 and the lower shell 102 are seamlessly welded.

[0032] In this embodiment, the steam seal housing 1 adopts seamless welding of the upper shell 101 and the lower shell 102, which ensures that the transmission hub mechanism 5 is installed inside the lower shell 102 before the product is manufactured, and the upper shell 101 is fixed to the upper part of the lower shell 102 by seamless welding technology, forming a complete steam turbine structure with high sealing performance.

[0033] The working principle and use process of the utility model are as follows: when in use, steam enters the interior of the steam seal housing 1 through the air inlet chamber 2, and a part of the steam circulates through the internal annular air inlet chamber 11 of the steam seal housing 1 and is discharged from the air outlet chamber 4.

[0034] Afterwards, when the internal pressure of the steam seal shell 1 is too high, another part of the wind steam enters from the pressure relief steam pipe 3 and is discharged to the air outlet chamber 4 from the one-way ventilation and pressure relief mechanism 6, thereby ensuring the internal circulation efficiency of the turbine steam seal structure. At the same time, the excess steam is guided and discharged, which effectively reduces the internal pressure of the steam seal structure. The rotation principle of the torque spring 603 is utilized to ensure the one-way closure of the opening and closing valve 604, thereby preventing steam from flowing back into the steam seal structure.

[0035] In summary, the high-sealing steam turbine steam seal structure ensures the internal circulation efficiency of the steam turbine steam seal structure by means of the pressure relief steam pipe 3 arranged at the bottom of the steam seal housing 1, while guiding and discharging excess steam, thereby effectively reducing the internal pressure of the steam seal structure. The rotation principle of the torque spring 603 is utilized to ensure the one-way closure of the opening and closing valve 604, thereby preventing steam from flowing back into the steam seal structure, thereby improving the airtightness of the steam seal structure.

[0036] It should be noted that, in this article, terms such as "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0037] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A steam seal structure for a steam turbine with high sealing performance, comprising a steam seal housing (1), an air inlet chamber (2) arranged at the upper part of the steam seal housing (1), and a pressure relief steam pipe (3) arranged at the bottom of the steam seal housing (1), wherein the pressure relief steam pipe (3) is arranged so that when steam enters the air inlet chamber (2), the pressure relief steam pipe (3) discharges excess steam in the steam seal housing (1) separately, and is characterized in that: Also includes: An air outlet chamber (4) is arranged at one end of the bottom of the steam seal housing (1), and one end of the air outlet chamber (4) is connected to one end of the pressure relief steam pipe (3); A transmission hub mechanism (5) arranged inside the steam seal housing (1), the transmission hub mechanism (5) comprising an axial hub (501), a roller shaft (502) and a moving blade cascade (503); A one-way venting pressure relief mechanism (6) arranged on the pressure relief steam pipe (3), the one-way venting pressure relief mechanism (6) comprising a one-way vent valve (601), a receiving door (602), a torque spring (603) and an opening and closing valve (604); A stationary blade grid (7) is arranged inside the steam seal housing (1), and the number of the stationary blade grid (7) is several.

2. A steam turbine seal structure with high sealing performance according to claim 1, characterized in that: Both ends of the axial hub (501) are fixedly connected to roller shafts (502), and a moving blade cascade (503) is arranged on the surface of the axial hub (501).

3. A high-sealability steam turbine steam seal structure according to claim 2, characterized in that: There are a plurality of movable blade cascades (503), and the plurality of movable blade cascades (503) are evenly distributed on the surface of the axial hub (501) in a straight line.

4. The high-sealing steam turbine seal structure according to claim 1, characterized in that: Both ends of the one-way vent valve (601) are connected to the pressure relief steam pipe (3), and a receiving door (602) is fixedly connected to the middle part of the one-way vent valve (601). The surface of the receiving door (602) is rotatably connected to an opening and closing valve (604) via a torque spring (603).

5. A steam turbine seal structure with high sealing performance according to claim 4, characterized in that: Both ends of the surface of the one-way vent valve (601) are connected to the pressure relief steam pipe (3) through threaded bolts (8) and threaded caps (9), and both ends of the one-way vent valve (601) are fitted with sealing rubber rings (10).

6. The high-sealing steam turbine steam seal structure according to claim 1, characterized in that: A plurality of the stationary blade rows (7) are evenly distributed in a straight line inside the steam seal housing (1), and the inner ends of adjacent stationary blade rows (7) are both embedded with moving blade rows (503).

7. The high-sealability steam turbine steam seal structure according to claim 1, characterized in that: The surfaces of the roller shaft (502) are rotatably connected to both ends of a steam seal housing (1), and the steam seal housing (1) comprises an upper shell (101) and a lower shell (102), and the upper shell (101) and the lower shell (102) are seamlessly welded.

8. The high-sealability steam turbine steam seal structure according to claim 1, characterized in that: The transmission hub mechanism (5) is rotatably connected to the interior of the steam seal housing (1), and the transmission hub mechanism (5) forms an annular air inlet chamber (11) inside the steam seal housing (1).

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