Nozzle chamber structure capable of reducing rotor thrust

Abstract

The invention discloses a nozzle chamber structure capable of reducing rotor thrust, and belongs to the technical field of steam turbine parts. According to the invention, the technical problems that a radial steam seal is arranged between the maximum diameter and the minimum diameter of an existing rotor wheel disc for sealing, so that the stress area is large, the forward thrust to a rotor is large, and the phenomenon of overheating tile burning of a unit is easily caused are solved. The nozzle chamber structure capable of reducing the thrust of the rotor comprises a nozzle chamber, a nozzle set, a transverse steam seal and a steam inlet pipe, the upper end of the nozzle chamber is communicated with the steam inlet pipe, the nozzle set is installed at a steam outlet of the nozzle chamber, steam flows to the rotor through the nozzle set, and the transverse steam seal arranged in the horizontal direction is further installed on the outer wall of the nozzle chamber. The two circles of transverse steam seals are arranged on the upper side and the lower side of the nozzle set correspondingly. And the stress area of the rotor is reduced, so that the axial thrust of the rotor is reduced. The invention is used for the turbine nozzle chamber.

Description

Technical Field

[0001] The invention relates to a nozzle chamber structure capable of reducing rotor thrust, belonging to the technical field of steam turbine parts. Background Art

[0002] The nozzle chamber is an important component of the steam turbine. The new steam of the steam turbine enters the nozzle through the steam pipe and then enters the rotor to perform work, playing a connecting role. Usually, after the steam comes out of the nozzle, it will first flow into the space between the nozzle and the rotor end face. A radial steam seal will be set between the maximum diameter and the minimum diameter of the rotor disk for sealing. Since the steam pressure after coming out of the nozzle is relatively large, and the force area between the maximum diameter and the minimum diameter of the rotor disk is relatively large, a relatively large positive thrust will be generated on the rotor. Since the rotor thrust bearing of a small unit cannot be very large due to space limitations, it is very likely that the unit will overheat and burn due to excessive rotor thrust during operation.

[0003] In summary, a radial steam seal is set between the maximum diameter and the minimum diameter of the existing rotor wheel for sealing. The force-bearing area is large, resulting in a large positive thrust on the rotor, which in turn easily causes the technical problem of overheating and burning of the unit. Summary of the invention

[0004] The present invention aims to solve the technical problem that a radial steam seal is set between the maximum diameter and the minimum diameter of the existing rotor wheel disc for sealing, which results in a large force-bearing area, resulting in a large positive thrust on the rotor, which in turn easily causes overheating and burning of the unit, and thus provides a nozzle chamber structure that can reduce the rotor thrust.

[0005] The technical solution of the present invention is a nozzle chamber structure capable of reducing the thrust of a rotor, comprising a nozzle chamber, a nozzle group, a transverse steam seal and a steam inlet pipe, wherein the upper end of the nozzle chamber is connected to the steam inlet pipe, a nozzle group is installed at the steam outlet of the nozzle chamber, steam flows to the rotor through the nozzle group, and a transverse steam seal arranged in a horizontal direction is installed on the outer wall of the nozzle chamber, and two circles of transverse steam seals are respectively arranged on the upper and lower sides of the nozzle group.

[0006] As another improvement of the present invention, it also includes a connecting flange, and the nozzle chamber is sealed and connected to the steam inlet pipe via the connecting flange.

[0007] As another improvement of the present invention, it also includes connecting bolts, and the connecting flange is sealed and connected to the steam inlet pipe through the connecting bolts.

[0008] As another improvement of the present invention, it also includes an expansion joint, and the connecting flange is connected to the external cylinder through the expansion joint.

[0009] As another improvement of the present invention, it also includes a spring. An installation groove along the horizontal direction is opened on the outer wall of the nozzle chamber. The transverse steam seal is installed on the nozzle chamber through the installation groove. One end of the spring is installed on the right side of the transverse steam seal, and the other end of the spring is installed on the inner wall of the installation groove. The transverse steam seal is displaced left and right by the spring.

[0010] As another improvement of the present invention, the external rotor is arranged on the left side of the transverse steam seal, and a steam seal groove matching the shape of the transverse steam seal is provided on the external rotor. The transverse steam seal has multiple sections arranged from top to bottom.

[0011] As another improvement of the present invention, the number of transverse steam seals arranged from top to bottom is 4 to 6 sections.

[0012] As another improvement of the present invention, the steam in the area enclosed by the two circles of transverse steam seals forms a pressure surface A on the external rotor surface, and the pressure surface A is annular.

[0013] Beneficial effects of the present invention:

[0014] 1. The present invention provides a nozzle chamber structure capable of reducing rotor thrust. Two circles of transverse steam seals are arranged on the upper and lower sides of the nozzle group to cooperate with the rotor, so that a very small annular area is formed to seal the high-pressure steam. The area outside the annular area is a low-pressure steam area, which has little effect on the rotor thrust. This new nozzle chamber structure changes the area of ​​the rotor end face filled with high-pressure steam from the larger B surface to the smaller A surface, greatly reducing the force-bearing area, thereby reducing the axial thrust of the rotor. It can greatly reduce the area of ​​the rotor bearing high-pressure steam, thereby reducing the thrust received by the rotor to meet the safe operation of the unit.

[0015] 2. The transverse steam seal is equipped with a special spring for tightening, and the transverse steam seal can be expanded and contracted to prevent wear on the rotor.

[0016] 3. The nozzle chamber and the cylinder are sealed and connected through the connecting flange and expansion joint to prevent steam leakage and ensure the expansion margin between the nozzle chamber and the cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of a nozzle chamber structure capable of reducing rotor thrust of the present invention.

[0018] Figure 2 This is a schematic diagram of the layout of the transverse steam seal, where the arrow direction is the steam flow direction.

[0019] Figure 3 It is a cross-sectional schematic diagram of the nozzle chamber. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the examples of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention. In the description of the present invention, it should be explained that the positional relationships indicated by the terms "upper", "lower", "left", "right", etc. are only based on the positional relationships of the orientations shown in the drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the referred components have specific orientations, are constructed and operated in specific orientations, and therefore cannot be understood as limitations on the present invention.

[0021] Specific implementation method 1: Combination Figures 1 to 3 The present embodiment is described. The present embodiment is a nozzle chamber structure capable of reducing the thrust of a rotor, comprising a nozzle chamber 1, a nozzle group 2, a transverse steam seal 4 and a steam inlet pipe 8. The upper end of the nozzle chamber 1 is connected to the steam inlet pipe 8. The steam outlet of the nozzle chamber 1 is provided with a nozzle group 2. The steam flows toward the rotor through the nozzle group 2. A transverse steam seal 4 arranged in a horizontal direction is provided on the outer wall of the nozzle chamber 1. Two circles of the transverse steam seal 4 are respectively arranged on the upper and lower sides of the nozzle group 2.

[0022] The steam turbine is mainly composed of a rotor, a nozzle chamber and a cylinder. The steam first enters the nozzle chamber from the steam inlet pipe and the connecting flange, then flows out through the nozzle group, and then enters the rotor. After flowing through each stage of the steam turbine, the steam flows into the cylinder and is discharged to the turbine condensing equipment. If a conventional radial steam seal is used for design, the force-bearing surface of the rotor at the nozzle outlet is the B surface, which can be seen to be very large. Since the pressure of the steam at the nozzle outlet is relatively large, this causes excessive thrust of the rotor, which makes the thrust bearing pad unable to bear it. For this reason, an axial steam seal is designed to seal high-pressure steam. Two circles of transverse steam seals are set on the upper and lower sides of the nozzle group to cooperate with the rotor, so that a very small annular area is formed to seal high-pressure steam. Outside the annular area are low-pressure steam areas, which have little effect on the rotor thrust. This new nozzle chamber structure changes the area of ​​the rotor end face filled with high-pressure steam from the larger B surface to the smaller A surface, greatly reducing the force-bearing area, thereby reducing the axial thrust of the rotor, so that some small-area thrust bearings can meet the use requirements. And meet the safe operation of the unit.

[0023] Specific implementation method 2: Combination Figures 1 to 3 This embodiment is described. The difference between this embodiment and the first embodiment is that this embodiment further includes a connecting flange 7, and the nozzle chamber 1 is sealedly connected to the steam inlet pipe 8 through the connecting flange 7. The sealing connection is performed through the connecting flange to prevent steam leakage. Other components and connection methods are the same as those of the first embodiment.

[0024] Specific implementation method three: Combination Figures 1 to 3 This embodiment is described. The difference between this embodiment and the specific embodiment 1 is that this embodiment also includes a connecting bolt 6, and the connecting flange 7 is sealed and connected to the steam inlet pipe 8 through the connecting bolt 6. The purpose of such design is simple structure and high reliability. Other components and connection methods are the same as those of the specific embodiment 1 or 2.

[0025] Specific implementation method four: Combination Figures 1 to 3 This embodiment is described. The difference between this embodiment and the specific embodiment 1 is that this embodiment also includes an expansion joint 5, and the connecting flange 7 is connected to the external cylinder through the expansion joint 5. The expansion margin between the nozzle chamber and the cylinder is guaranteed. The other components and connection methods are the same as any one of the specific embodiments 1 to 3.

[0026] Specific implementation method five: Combination Figures 1 to 3 This embodiment is described. The difference between this embodiment and the specific embodiment 1 is that this embodiment also includes a spring 3, a mounting groove along the horizontal direction is opened on the outer wall of the nozzle chamber 1, and the transverse steam seal 4 is installed on the nozzle chamber 1 through the mounting groove. One end of the spring 3 is installed on the right side of the transverse steam seal 4, and the other end of the spring 3 is installed on the inner wall of the mounting groove. The transverse steam seal 4 is displaced left and right through the spring 3. The transverse steam seal is equipped with a special spring for tightening, and the transverse steam seal can be extended and retracted to prevent wear on the rotor. Other components and connection methods are the same as any one of the specific embodiments 1 to 4.

[0027] Specific implementation method six: Combination Figures 1 to 3 This embodiment is described. The difference between this embodiment and the first embodiment is that the external rotor is arranged on the left side of the transverse steam seal, and a steam seal groove matching the shape of the transverse steam seal is provided on the external rotor. The transverse steam seal is arranged in multiple sections from top to bottom. The other components and connection methods are the same as any one of the first to fifth embodiments.

[0028] Specific implementation method seven: Combination Figures 1 to 3 This embodiment is described. The difference between this embodiment and the first embodiment is that the number of transverse steam seals arranged from top to bottom is 4 to 6. The other components and connection methods are the same as any one of the first to sixth embodiments.

[0029] Specific implementation method eight: Combination Figures 1 to 3 This embodiment is described. The difference between this embodiment and the first embodiment is that the steam in the enclosed area of ​​the two circles of transverse steam seals 4 forms a pressure surface A on the outer rotor surface, and the pressure surface A is annular. The force-bearing area of ​​the annular pressure surface is greatly reduced, thereby reducing the axial thrust of the rotor. The other components and connection methods are the same as any one of the first to seventh embodiments.

[0030] Combination Figures 1 to 3 The working principle of the present invention is described:

[0031] The steam turbine is mainly composed of a rotor, a nozzle chamber and a cylinder. The steam first enters the nozzle chamber from the steam inlet pipe and the connecting flange, then flows out through the nozzle group, and then enters the rotor. After passing through each stage of the steam turbine, the steam flows into the cylinder and is discharged to the turbine condensing equipment. Two circles of transverse steam seals are set on the upper and lower sides of the nozzle group to cooperate with the rotor, so that a very small annular area is formed to seal the high-pressure steam. The area outside the annular area is a low-pressure steam area, which has little effect on the rotor thrust. This new nozzle chamber structure changes the area of ​​the original high-pressure steam filling the rotor end face from the larger B side to the smaller A side, greatly reducing the force area, thereby reducing the axial thrust of the rotor. It can greatly reduce the area of ​​the rotor bearing high-pressure steam, thereby reducing the thrust of the rotor to meet the safe operation of the unit.

[0032] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A nozzle chamber structure capable of reducing rotor thrust, characterized in that It comprises a nozzle chamber (1), a nozzle group (2), a transverse steam seal (4) and a steam inlet pipe (8). The upper end of the nozzle chamber (1) is connected to the steam inlet pipe (8). The steam outlet of the nozzle chamber (1) is equipped with a nozzle group (2). Steam flows toward the rotor through the nozzle group (2). A transverse steam seal (4) is installed in a horizontal direction on the outer wall of the nozzle chamber (1). Two circles of the transverse steam seal (4) are respectively arranged on the upper side and the lower side of the nozzle group (2).

2. A nozzle chamber structure capable of reducing rotor thrust according to claim 1, characterized in that It also includes a connecting flange (7), and the nozzle chamber (1) is sealedly connected to the steam inlet pipe (8) via the connecting flange (7).

3. A nozzle chamber structure capable of reducing rotor thrust according to claim 2, characterized in that It also includes connecting bolts (6), and the connecting flange (7) is sealedly connected to the steam inlet pipe (8) via the connecting bolts (6).

4. A nozzle chamber structure capable of reducing rotor thrust according to claim 2, characterized in that It also includes an expansion joint (5), and the connecting flange (7) is connected to the external cylinder through the expansion joint (5).

5. The nozzle chamber structure capable of reducing rotor thrust according to claim 1, characterized in that It also includes a spring (3). An installation groove along the horizontal direction is opened on the outer wall of the nozzle chamber (1). The transverse steam seal (4) is installed on the nozzle chamber (1) through the installation groove. One end of the spring (3) is installed on the right side of the transverse steam seal (4). The other end of the spring (3) is installed on the inner wall of the installation groove. The transverse steam seal (4) is displaced left and right through the spring (3).

6. A nozzle chamber structure capable of reducing rotor thrust according to claim 5, characterized in that: The external rotor is arranged on the left side of the transverse steam seal (4), and a steam seal groove matching the shape of the transverse steam seal (4) is arranged on the external rotor. The transverse steam seal (4) has multiple sections arranged from top to bottom.

7. The nozzle chamber structure capable of reducing rotor thrust according to claim 6, characterized in that: The number of transverse steam seals (4) arranged from top to bottom is 4 to 6.

8. The nozzle chamber structure capable of reducing rotor thrust according to claim 1, characterized in that: The steam in the area enclosed by the two circles of transverse steam seals (4) forms a pressure surface A on the outer rotor surface, and the pressure surface A is annular.

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