A 50MW high temperature and high pressure single cylinder one-step adjustment extraction back pressure steam turbine

Abstract

A 50MW high-temperature and high-pressure single-cylinder, one-time adjustment, extraction back-pressure steam turbine relates to the field of steam turbine design. In order to solve the problems of large size, high cost, and uncontrollable steam extraction of traditional 50MW steam turbines. The two ends of the high and medium pressure cylinder modules in the present invention are supported on the front bearing box and the rear bearing box, and are divided into a high-pressure steam chamber and a medium-pressure steam chamber by a partition steam seal; two high-pressure regulating valves are arranged at the top of the high and medium pressure cylinder modules, and the other two high-pressure regulating valves are arranged at the side ends of the high and medium pressure cylinder modules; two medium-pressure regulating valves are arranged at the top of the high and medium pressure cylinder modules, and the other two medium-pressure regulating valves are arranged at the side ends of the high and medium pressure cylinder modules; the two main steam valves are respectively connected to the two groups of high-pressure regulating valves through two high-pressure steam pipes. The present invention is mainly used to improve the existing 50MW steam turbine unit so that it can meet the steam parameter requirements of existing work.

Description

Technical Field

[0001] The invention relates to the field of steam turbine design, and in particular to a 50MW high-temperature and high-pressure single-cylinder one-time adjustment steam extraction back-pressure steam turbine. Background Art

[0002] With the continuous development of society and the continuous improvement of industrial level, the traditional 50MW steam turbine has problems such as large size, high cost and uncontrollable steam extraction, which can no longer meet the current industrial production needs. Although valves can be set at the steam extraction port to control the steam extraction amount, the controllability of the steam extraction amount is very small. Therefore, a 50MW high-temperature and high-pressure single-cylinder one-time adjustment steam extraction back-pressure steam turbine is developed. Summary of the invention

[0003] The technical problem to be solved by the present invention is that the traditional 50MW steam turbine has the problems of large size, high cost, uncontrollable steam extraction volume, etc., and thus a 50MW high-temperature and high-pressure single-cylinder one-time adjustment steam extraction back-pressure steam turbine is provided.

[0004] The technical solution adopted by the present invention to solve the above technical problems is:

[0005] A 50MW high-temperature and high-pressure single-cylinder single-stage adjustment extraction back-pressure steam turbine, comprising two main steam valves, four high-pressure steam pipes, four high-pressure regulating valves, four medium-pressure regulating valves, a front bearing box, a high- and medium-pressure cylinder module, a rear bearing box, two end steam seals and a rotor; the adjustment end of the high- and medium-pressure cylinder module is supported on the front bearing box by a cat's claw, and the electrical end of the high- and medium-pressure cylinder module is supported on the rear bearing box by a cat's claw; one end of the rotor is installed in the front bearing box, and the other end of the rotor passes through the high- and medium-pressure cylinder module and is installed in the rear bearing box, and the two ends of the high- and medium-pressure cylinder module are sealed with an end steam seal respectively; the high- and medium-pressure cylinder module is a single-cylinder structure and is divided into a high-pressure steam chamber and a medium-pressure steam chamber by a partition steam seal, and a first steam extraction port is arranged at the bottom end of the high- and medium-pressure cylinder module, and the first steam extraction port is communicated with the high-pressure steam chamber; the four high-pressure regulating valves It is divided into two groups, and the two groups of high-pressure regulating valves are symmetrically arranged on the high- and medium-pressure cylinder modules. One high-pressure regulating valve in each group of high-pressure regulating valves is arranged at the top of the high- and medium-pressure cylinder modules and communicated with the high-pressure steam chamber, and the other high-pressure regulating valve in each group of high-pressure regulating valves is arranged at the side end of the high- and medium-pressure cylinder modules and communicated with the high-pressure steam chamber; the four medium-pressure regulating valves are divided into two groups, and the two groups of medium-pressure regulating valves are symmetrically arranged on the high- and medium-pressure cylinder modules. One medium-pressure regulating valve in each group of medium-pressure regulating valves is arranged at the top of the high- and medium-pressure cylinder modules and communicated with the high-pressure steam chamber and the medium-pressure steam chamber respectively, and the other medium-pressure regulating valve in each group of medium-pressure regulating valves is arranged at the side end of the high- and medium-pressure cylinder modules and communicated with the high-pressure steam chamber and the medium-pressure steam chamber respectively; the two main steam valves are respectively arranged in front of the front bearing box, and each main steam valve is connected to the two high-pressure regulating valves in each group of high-pressure regulating valves through two high-pressure steam pipes.

[0006] Furthermore, the medium-pressure regulating valve is a double-seat valve, one valve port of the medium-pressure regulating valve is connected to the high-pressure steam chamber of the high- and medium-pressure cylinder modules, and the other valve port of the medium-pressure regulating valve is connected to the medium-pressure steam chamber of the high- and medium-pressure cylinder modules.

[0007] Furthermore, the front bearing box and the rear bearing box are installed on the base frame through floor brackets.

[0008] Furthermore, the front end lower position of the high and medium pressure cylinder module is connected to the rear end lower position of the front bearing box through a set of centering beam push-pull structure components, and the rear end lower position of the high and medium pressure cylinder module is connected to the front end lower position of the rear bearing box through a set of centering beam push-pull structure components.

[0009] Furthermore, the centering beam push-pull structure assembly includes a centering beam and a plurality of positioning pins, the cross-section of the centering beam is an I-shape, and pin holes are provided at both ends of the centering beam; the two ends of the centering beam in the centering beam push-pull structure assembly for connecting the front bearing box and the high and medium pressure cylinder module are respectively abutted on the front bearing box and the high and medium pressure cylinder module, and are connected by a plurality of positioning pins; the two ends of the centering beam in the centering beam push-pull structure assembly for connecting the rear bearing box and the high and medium pressure cylinder module are respectively abutted on the rear bearing box and the high and medium pressure cylinder module, and are connected by a plurality of positioning pins.

[0010] Furthermore, the rotor adopts an integral forging structure.

[0011] Furthermore, the partition steam seal and the two end steam seals are both insert-type steam seals, and use a high-low tooth structure to reduce steam leakage.

[0012] Furthermore, in the high-pressure steam chamber of the high- and medium-pressure cylinder modules, each high-pressure regulating valve is arranged corresponding to a regulating stage nozzle group.

[0013] Furthermore, in the medium-pressure steam chamber of the high- and medium-pressure cylinder modules, each medium-pressure regulating valve is arranged corresponding to a regulating stage nozzle group.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1. In the present invention, when the steam parameters from the boiler change, the opening of the four medium-pressure regulating valves provided on the high- and medium-pressure cylinder modules can be adjusted to maintain the stability of the steam extraction parameters, so the steam turbine of the present application has the ability to extract steam at a constant pressure;

[0016] 2. The cylinder body in the present invention adopts a single-cylinder form, and the medium-pressure regulating valve adopts a double-seat valve, which saves space and cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, as a part of this application, are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention, but do not constitute improper limitations on the present invention.

[0018] Figure 1 is a side view of the present invention;

[0019] Figure 2 A top view of the present invention;

[0020] Figure 3 It is a schematic diagram of the overall structure of the present invention;

[0021] Figure 4 for Figure 3 A partial enlarged view of point A in the middle.

[0022] In the figure: 1-main steam valve; 2-high-pressure steam guide pipe; 3-high-pressure regulating valve; 4-medium-pressure regulating valve; 5-front bearing box; 6-high and medium-pressure cylinder modules; 6-1-high-pressure steam chamber; 6-2-medium-pressure steam chamber; 6-3-first steam extraction port; 7-rear bearing box; 8-end steam seal; 9-partition steam seal; 10-rotor; 11-centering beam push-pull structure assembly; 11-1-centering beam; 11-2-locating pin. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0024] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0025] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] See also Figures 1 to 4 As shown, the embodiment of the present application provides a 50MW high-temperature and high-pressure single-cylinder one-time adjustment extraction back-pressure steam turbine, including two main steam valves 1, four high-pressure steam pipes 2, four high-pressure regulating valves 3, four medium-pressure regulating valves 4, a front bearing box 5, a high- and medium-pressure cylinder module 6, a rear bearing box 7, two end steam seals 8 and a rotor 10;

[0027] The front bearing box 5 and the rear bearing box 7 are respectively arranged at the front and rear of the high and medium pressure cylinder module 6, the regulating end of the high and medium pressure cylinder module 6 is supported on the front bearing box 5 through a cat's claw, and the electrical end of the high and medium pressure cylinder module 6 is supported on the rear bearing box 7 through a cat's claw; one end of the rotor 10 is installed in the front bearing box 5, and the other end of the rotor 10 passes through the high and medium pressure cylinder module 6 and is installed in the rear bearing box 7, and the two ends of the high and medium pressure cylinder module 6 are sealed with the rotor 10 through an end steam seal 8; the high and medium pressure cylinder module 6 is a single cylinder structure and is divided into a high-pressure steam chamber 6-1 and a medium-pressure steam chamber 6-2 by a partition steam seal 9. There are 10 levels of work in the high and medium pressure cylinder module 6, and there are one-stage regulating stage work and three-stage pressure stage work in the high-pressure steam chamber 6-1, and one-stage regulating stage work and five-stage pressure stage work in the medium-pressure steam chamber 6-2; a first steam extraction port 6-3 is arranged at the bottom end of the high and medium pressure cylinder module 6, and the first steam extraction port 6-3 is communicated with the high-pressure steam chamber 6-1;

[0028] The four high-pressure regulating valves 3 are divided into two groups, and the two groups of high-pressure regulating valves 3 are symmetrically arranged at the front end of the high- and medium-pressure cylinder modules 6. One high-pressure regulating valve 3 in each group of high-pressure regulating valves 3 is arranged at the top of the high- and medium-pressure cylinder modules 6 and communicates with the high-pressure steam chamber 6-1, and the other high-pressure regulating valve 3 in each group of high-pressure regulating valves 3 is arranged at the side end of the high- and medium-pressure cylinder modules 6 and communicates with the high-pressure steam chamber 6-1; the four medium-pressure regulating valves 4 are divided into two groups, and the two groups of medium-pressure regulating valves 4 are symmetrically arranged at the middle position of the high- and medium-pressure cylinder modules 6. One medium-pressure regulating valve 4 in each group of medium-pressure regulating valves 4 is arranged at the top of the high- and medium-pressure cylinder modules 6 and communicates with the high-pressure steam chamber 6-1 and the medium-pressure steam chamber 6-2, respectively, and the other medium-pressure regulating valve 4 in each group of medium-pressure regulating valves 4 is arranged at the side end of the high- and medium-pressure cylinder modules 6 and communicates with the high-pressure steam chamber 6-1 and the medium-pressure steam chamber 6-2, respectively; the two main steam valves 1 are respectively arranged in front of the front bearing box 5, and each main steam valve 1 is connected to the two high-pressure regulating valves 3 in each group of high-pressure regulating valves 3 through two high-pressure steam pipes 2.

[0029] In this embodiment, the main steam enters two main steam valves 1 through four steam pipes, then enters four high-pressure regulating valves 3 through two main steam valves 1 and four high-pressure steam pipes 2, and then enters the high-pressure steam chamber 6-1 in the high- and medium-pressure cylinder module 6 through the four high-pressure regulating valves 3. After doing work through four regulating stage nozzle groups and three pressure stages, part of the steam is extracted through the first steam extraction port 6-3, and the other part of the steam enters the medium-pressure steam chamber 6-2 in the high- and medium-pressure cylinder module 6 through four medium-pressure regulating valves 4, and is discharged after doing work through the four regulating stage nozzle groups and five pressure stages in the medium-pressure steam chamber 6-2. The steam entering the high-pressure regulating valve 3 controls the corresponding four nozzle groups in the high-pressure steam chamber 6-1 to achieve the steam distribution requirements of the unit.

[0030] In this embodiment, when the steam parameters from the boiler change, the opening of the four medium-pressure regulating valves 4 provided on the high- and medium-pressure cylinder modules 6 can be adjusted to maintain the stability of the extraction parameters, so the steam turbine of this application has the ability to extract steam at a constant pressure. If there is no seat cylinder valve, and the valve is designed to sit on the foundation, the high-pressure steam after work needs to be guided out of the cylinder through the steam guide pipe to enter the valve, and then pass through the medium-pressure valve and re-enter the cylinder through the steam guide pipe. The setting of the seat cylinder valve not only eliminates pipeline losses, but also saves space.

[0031] This unit consists of 10 stages, and the high-pressure steam inlet regulation method adopts nozzle regulation. The flow channel design of the nozzle adopts the advanced meridian contraction static blade theory, which effectively reduces the secondary flow loss of the static blade; the dynamic and static blade profiles all adopt the blade profiles with good aerodynamic performance and high efficiency in full three-dimensional design to improve the flow efficiency; the regulating stage nozzle consists of four sections, and the inner ring arc section of each nozzle is directly milled, and the outer ring and the shroud are connected to the inner ring by welding, and then installed on the nozzle chamber, fixed by positioning pins, and sealed at both ends by sealing keys.

[0032] In a possible embodiment, the medium-pressure regulating valve 4 is a double-seat valve, one valve port of the medium-pressure regulating valve 4 is connected to the high-pressure steam chamber 6-1 of the high- and medium-pressure cylinder module 6, and the other valve port of the medium-pressure regulating valve 4 is connected to the medium-pressure steam chamber 6-2 of the high- and medium-pressure cylinder module 6.

[0033] In this embodiment, the medium-pressure regulating valve adopts a double-seat valve design, which has a large flow capacity and occupies a small space.

[0034] In a possible embodiment, the front bearing box 5 and the rear bearing box 7 are installed on the base frame through a floor bracket.

[0035] In a possible embodiment, the front end lower position of the high and medium pressure cylinder module 6 is connected to the rear end lower position of the front bearing box 5 through a set of centering beam push-pull structure components 11, and the rear end lower position of the high and medium pressure cylinder module 6 is connected to the front end lower position of the rear bearing box 7 through a set of centering beam push-pull structure components 11.

[0036] In this embodiment, a centering beam push-pull structure is used between the bearing box and the high and medium pressure cylinder module 6, and they are fastened and positioned with bolts and positioning pins, so that the cylinder can maintain a correct axial position relative to the bearing seat of the bearing box.

[0037] In a possible embodiment, the centering beam push-pull structure assembly 11 includes a centering beam 11-1 and a plurality of positioning pins 11-2, the cross-section of the centering beam 11-1 is an I-shape, and pin holes are provided at both ends of the centering beam 11-1; the two ends of the centering beam 11-1 in the centering beam push-pull structure assembly 11 for connecting the front bearing box 5 and the high and medium pressure cylinder module 6 are respectively abutted on the front bearing box 5 and the high and medium pressure cylinder module 6, and are connected by a plurality of positioning pins 11-2; the two ends of the centering beam 11-1 in the centering beam push-pull structure assembly 11 for connecting the rear bearing box 7 and the high and medium pressure cylinder module 6 are respectively abutted on the rear bearing box 7 and the high and medium pressure cylinder module 6, and are connected by a plurality of positioning pins 11-2.

[0038] In a possible embodiment, the rotor 10 adopts an integral forging structure.

[0039] In this embodiment, the rotor 10 includes an impeller and a main shaft, and the impeller and the main shaft are forged as one piece, so that the structure is compact, the number of assembly parts is small, the rigidity is good, and the rotor strength performance is high.

[0040] In a possible embodiment, the partition steam seal 9 and the two end steam seals 8 are both insert-type steam seals, and use a high-low tooth structure to reduce steam leakage.

[0041] In this embodiment, except for the blade tip steam seal, a high and low tooth structure is used to reduce the steam leakage and reduce the steam leakage loss. The radial clearance and axial clearance of the steam seal are reasonably placed, which not only reduces the steam leakage loss but also ensures the requirements of unit start-up and shutdown and peak regulation, thereby ensuring the economy and safety of the unit.

[0042] In a possible embodiment, in the high-pressure steam chamber 6 - 1 of the high- and medium-pressure cylinder module 6 , each high-pressure regulating valve 3 is arranged corresponding to a regulating stage nozzle group.

[0043] In this embodiment, the regulating stage nozzle is composed of four sections. The inner ring arc segment of each nozzle section is directly milled and formed. The outer ring and the circumferential belt are connected to the inner ring by welding, and then installed on the nozzle chamber, fixed by positioning pins, and sealed at both ends by sealing keys.

[0044] In a possible embodiment, in the medium-pressure steam chamber 6 - 2 of the high- and medium-pressure cylinder module 6 , each medium-pressure regulating valve 4 is arranged corresponding to a regulating stage nozzle group.

[0045] In this embodiment, the regulating stage nozzle is composed of four sections. The inner ring arc segment of each nozzle section is directly milled and formed. The outer ring and the circumferential belt are connected to the inner ring by welding, and then installed on the nozzle chamber, fixed by positioning pins, and sealed at both ends by sealing keys.

[0046] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be used in other described embodiments.

Claims

1. A 50MW high temperature and high pressure single cylinder one-time adjustment extraction back pressure steam turbine, characterized in that: It comprises two main steam valves (1), four high-pressure steam pipes (2), four high-pressure regulating valves (3), four medium-pressure regulating valves (4), a front bearing box (5), a high- and medium-pressure cylinder module (6), a rear bearing box (7), two end steam seals (8) and a rotor (10); The regulating end of the high and medium pressure cylinder module (6) is supported on the front bearing box (5) through a cat's claw, and the electrical end of the high and medium pressure cylinder module (6) is supported on the rear bearing box (7) through a cat's claw; one end of the rotor (10) is installed in the front bearing box (5), and the other end of the rotor (10) passes through the high and medium pressure cylinder module (6) and is installed in the rear bearing box (7); the two ends of the high and medium pressure cylinder module (6) and the rotor (10) are sealed by an end steam seal (8); the high and medium pressure cylinder module (6) is a single cylinder structure and is divided into a high-pressure steam chamber (6-1) and a medium-pressure steam chamber (6-2) by a partition steam seal (9); a first steam extraction port (6-3) is provided at the bottom end of the high and medium pressure cylinder module (6), and the first steam extraction port (6-3) is communicated with the high-pressure steam chamber (6-1); The four high-pressure regulating valves (3) are divided into two groups. The two groups of high-pressure regulating valves (3) are symmetrically arranged on the high- and medium-pressure cylinder modules (6). One high-pressure regulating valve (3) in each group of high-pressure regulating valves (3) is arranged at the top of the high- and medium-pressure cylinder modules (6) and communicates with the high-pressure steam chamber (6-1). The other high-pressure regulating valve (3) in each group of high-pressure regulating valves (3) is arranged at the side end of the high- and medium-pressure cylinder modules (6) and communicates with the high-pressure steam chamber (6-1). The four medium-pressure regulating valves (4) are divided into two groups. The two groups of medium-pressure regulating valves (4) are symmetrically arranged on the high- and medium-pressure cylinder modules (6). Each group of medium-pressure regulating valves ( One of the medium-pressure regulating valves (4) is arranged at the top end of the high- and medium-pressure cylinder modules (6) and is communicated with the high-pressure steam chamber (6-1) and the medium-pressure steam chamber (6-2), respectively; another medium-pressure regulating valve (4) in each group of medium-pressure regulating valves (4) is arranged at the side end of the high- and medium-pressure cylinder modules (6) and is communicated with the high-pressure steam chamber (6-1) and the medium-pressure steam chamber (6-2), respectively; the two main steam valves (1) are arranged in front of the front bearing box (5), respectively; each main steam valve (1) is connected to the two high-pressure regulating valves (3) in each group of high-pressure regulating valves (3) through two high-pressure steam guide pipes (2); The medium-pressure regulating valve (4) is a double-seat valve, one valve port of the medium-pressure regulating valve (4) is connected to the high-pressure steam chamber (6-1) of the high- and medium-pressure cylinder module (6), and the other valve port of the medium-pressure regulating valve (4) is connected to the medium-pressure steam chamber (6-2) of the high- and medium-pressure cylinder module (6); The front lower part of the high and medium pressure cylinder module (6) is connected to the rear lower part of the front bearing box (5) via a set of centering beam push-pull structural components (11), and the rear lower part of the high and medium pressure cylinder module (6) is connected to the front lower part of the rear bearing box (7) via a set of centering beam push-pull structural components (11).

2. A 50MW high temperature and high pressure single cylinder one-time adjustment extraction back pressure steam turbine according to claim 1, characterized in that: The centering beam push-pull structural component (11) comprises a centering beam (11-1) and a plurality of positioning pins (11-2); the cross section of the centering beam (11-1) is an I-shaped beam, and pin holes are formed at both ends of the centering beam (11-1); the two ends of the centering beam (11-1) in the centering beam push-pull structural component (11) used to connect the front bearing box (5) and the high and medium pressure cylinder module (6) are respectively abutted on the front bearing box (5) and the high and medium pressure cylinder module (6), and are connected by means of the plurality of positioning pins (11-2); the two ends of the centering beam (11-1) in the centering beam push-pull structural component (11) used to connect the rear bearing box (7) and the high and medium pressure cylinder module (6) are respectively abutted on the rear bearing box (7) and the high and medium pressure cylinder module (6), and are connected by means of the plurality of positioning pins (11-2).

3. A 50MW high temperature and high pressure single cylinder one-time adjustment extraction back pressure steam turbine according to claim 2, characterized in that: The rotor (10) adopts an integral forging structure.

4. A 50MW high temperature and high pressure single cylinder one-time adjustment extraction back pressure steam turbine according to claim 3, characterized in that: The partition steam seal (9) and the two end steam seals (8) are both insert-type steam seals, and adopt a high-low tooth structure to reduce steam leakage.

5. A 50MW high temperature and high pressure single cylinder one-time adjustment extraction back pressure steam turbine according to claim 4, characterized in that: In the high-pressure steam chamber (6-1) of the high- and medium-pressure cylinder module (6), each high-pressure regulating valve (3) is arranged corresponding to a regulating stage nozzle group.

6. A 50MW high temperature and high pressure single cylinder one-time adjustment extraction back pressure steam turbine according to claim 5, characterized in that: In the medium-pressure steam chamber (6-2) of the high- and medium-pressure cylinder module (6), each medium-pressure regulating valve (4) is arranged corresponding to a regulating stage nozzle group.

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