Supercritical ultrahigh-temperature single-cylinder reheating condensing steam turbine

Abstract

The invention relates to the technical field of steam turbines, in particular to a supercritical ultrahigh-temperature single-cylinder reheating condensing steam turbine which comprises an outer cylinder and a rotor arranged in the outer cylinder in a penetrating mode, and a high-pressure through-flow module and a medium-low-pressure through-flow module are sequentially arranged between the outer cylinder and the rotor from front to back. Main steam enters a high-pressure steam inlet of the high-pressure through-flow module through the high-pressure main adjusting combined steam valve, an adjusting stage used for achieving enthalpy drop of the main steam is arranged at the position, close to the high-pressure steam inlet, in the high-pressure through-flow module, and a high-pressure steam outlet of the high-pressure through-flow module is connected with an inlet of the reheater. An outlet of the reheater is connected with a steam inlet of the medium-low pressure through-flow module through a reheating main adjusting combined steam valve. The high-pressure through-flow module and the medium-low-pressure through-flow module are integrated in the same outer cylinder, so that the axial span of the unit is greatly shortened, the cost is greatly reduced, the structure is more compact, and the occupied space is reduced. The steam inlet mode of certain enthalpy drop of main steam is achieved by arranging the adjusting stage, and the wide-load operation requirement can be met.

Description

Technical Field

[0001] The invention relates to the technical field of steam turbines, and in particular to a supercritical ultra-high temperature single-cylinder reheat condensing steam turbine. Background Art

[0002] The production of steel is accompanied by a large amount of blast furnace gas, converter gas and coke oven gas. After deducting the gas used for the production process, there is still a large amount of surplus gas. The steel industry should make full use of combustible gases such as blast furnace gas and converter gas and various types of steam, and use self-provided power stations as the main integrated means to promote energy conservation and consumption reduction in steel enterprises. By installing new high-parameter high-efficiency energy-saving generator sets or upgrading and replacing the original old units, the optimal allocation of resources of steel enterprises can be achieved, the comprehensive energy consumption and production costs of enterprises can be reduced, and the economic benefits and market competitiveness of enterprises can be increased. At the same time, waste gas emissions can also be reduced to achieve the purpose of environmentally friendly production.

[0003] In recent years, due to the increasingly urgent tasks of energy conservation and emission reduction and equipment upgrading and transformation, the ultra-high pressure intermediate reheating technology previously used in large coal-fired units has gradually developed towards miniaturization. In 2017, the metallurgical industry launched a small subcritical coal gas power generation (80MW-135MW) application project. At present, there are more than 80 sets of 80MW, 100MW, 120MW, and 135MW small subcritical coal gas power generation units in China, and more than 20 sets have been put into production. With the advancement of domestic power equipment manufacturing technology, the metallurgical industry has begun to launch high-efficiency supercritical coal gas power generation technology (135MW-150MW) since 2020. At present, there are 4 domestic 135MW and 145MW high-efficiency supercritical units, all of which are currently under construction.

[0004] At present, all small and medium-sized waste heat utilization units in service or under construction in China adopt a dual-cylinder layout solution, which generally has problems such as complex structure, large installation space, and high production and maintenance costs. Summary of the invention

[0005] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to provide a supercritical ultra-high temperature single-cylinder reheat condensing steam turbine with compact structure, small occupation space and low cost.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] The present invention provides a supercritical ultra-high temperature single-cylinder reheat condensing steam turbine, comprising an outer cylinder and a rotor inserted in the outer cylinder, a high-pressure flow module and a medium- and low-pressure flow module are arranged in sequence from front to back between the outer cylinder and the rotor, main steam enters the high-pressure steam inlet of the high-pressure flow module through a high-pressure main regulating combined steam valve, a regulating stage for achieving main steam enthalpy drop is provided inside the high-pressure flow module near the high-pressure steam inlet, the high-pressure exhaust port of the high-pressure flow module is connected to the inlet of a reheater, and the outlet of the reheater is connected to the steam inlet of the medium- and low-pressure flow module through the reheat main regulating combined steam valve.

[0008] Preferably, the high-pressure flow module realizes the main steam enthalpy drop by distributing steam through nozzles.

[0009] Preferably, the high-pressure flow-through modules and the medium- and low-pressure flow-through modules are arranged in a bidirectional counter-flow form.

[0010] Preferably, the high-pressure flow module includes a high-pressure inner cylinder, and the front and rear ends of the high-pressure inner cylinder are respectively provided with a first balance piston seal and a second balance piston seal; the medium and low pressure flow module includes a medium pressure inner cylinder and multiple stationary blade holding rings arranged in sequence from front to back.

[0011] Preferably, the rotor includes a high temperature section, an ultra-high temperature section and a low temperature section which are connected in sequence from front to back, the ultra-high temperature section is located at the rear end of the high pressure flow module and the front end of the medium and low pressure flow module, and the materials of the high temperature section, the ultra-high temperature section and the low temperature section are determined according to the temperature distribution of the flow area where they are located.

[0012] Preferably, the high temperature section is welded to the ultra-high temperature section, and the ultra-high temperature section is welded to the low temperature section.

[0013] Preferably, the outer cylinder comprises a front cylinder and an exhaust cylinder which are connected to each other, and the rear end of the front cylinder is connected to the front end of the exhaust cylinder to form an integrated outer cylinder.

[0014] Preferably, a large partition of last-stage hollow stationary blades is provided between the exhaust cylinder and the rotor.

[0015] Preferably, a floor-mounted sliding front bearing seat is provided on the front side of the outer cylinder, a radial thrust combined bearing is provided in the front bearing seat, a fixed rear bearing seat is provided at the rear end of the outer cylinder, a radial bearing is provided in the rear bearing seat, and the front and rear ends of the rotor are supported by the radial thrust combined bearing and the radial bearing respectively.

[0016] Preferably, two groups of high-pressure main regulating combined steam valves are provided, and the two groups of high-pressure main regulating combined steam valves are respectively arranged on both sides of the outer cylinder, and each group of high-pressure main regulating combined steam valves includes a high-pressure main steam valve and two high-pressure regulating steam valves, and each high-pressure regulating steam valve is connected to the high-pressure steam inlet of the high-pressure flow module.

[0017] Preferably, a group of reheat main regulating combined steam valves are provided, and the reheat main regulating combined steam valves are arranged on one side of the outer cylinder. The reheat main regulating combined steam valves include a reheat main steam valve and a reheat regulating steam valve, and the reheat regulating steam valve is connected to the steam inlet of the medium and low pressure flow module.

[0018] Compared with the prior art, the present invention has significant improvements:

[0019] The supercritical ultra-high temperature single-cylinder reheat condensing steam turbine of the present invention adopts a single-cylinder layout for the first time in the same-level and same-parameter units, integrating the high-pressure flow module and the medium-low pressure flow module in the same outer cylinder. Compared with the existing double-cylinder layout units, the axial span of the unit is greatly shortened, and the length of the whole machine can be shortened by 4 meters to 5 meters, and a set of middle bearing seats and support bearings and middle bearing seat accessories oil gear, steam seal, etc. are saved, so that the cost of the whole machine is greatly reduced, and the manufacturing cost can be reduced by more than 25%. In addition, the unit structure is more compact, and the axial space occupied by the equipment is reduced, so that the cost of plant construction is also greatly reduced, and the workload of unit installation and maintenance is significantly reduced. The supercritical ultra-high temperature single-cylinder reheat condensing steam turbine of the present invention adopts a steam inlet method in which a regulating stage is set at the high-pressure steam inlet of the high-pressure flow module to realize a certain degree of enthalpy drop of the main steam. It has the advantage of high flexibility, can adapt to wide load operation requirements, and ensure that the unit remains efficient at low load or large steam extraction requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall layout of a supercritical ultra-high temperature single-cylinder reheat condensing steam turbine according to an embodiment of the present invention.

[0021] Figure 2 It is a schematic longitudinal section diagram of a supercritical ultra-high temperature single-cylinder reheat condensing steam turbine according to an embodiment of the present invention.

[0022] The reference numerals are described as follows:

[0023] 1 Outer cylinder

[0024] 1.1 Front cylinder

[0025] 1.2 Exhaust Cylinder

[0026] 2 Rotors

[0027] 2.1 High temperature section

[0028] 2.2 Ultra-high temperature section

[0029] 2.3 Low temperature section

[0030] 2.4 First weld area

[0031] 2.5 Second weld area

[0032] 3 High-pressure main regulating combined steam valve

[0033] 4 Regulation level

[0034] 5 Reheat main regulating combined steam valve

[0035] 6 High pressure inner cylinder

[0036] 7 Medium pressure inner cylinder

[0037] 8 Stationary blade holding ring

[0038] 9 First balance piston seal

[0039] 10 Second balance piston seal

[0040] 11 Front steam seal

[0041] 12 Large baffle of the last stage hollow stator blade

[0042] 13 Exhaust guide ring and low-pressure water spray pipe assembly

[0043] 14 Rear steam seal

[0044] 15 Front bearing seat

[0045] 16 Radial thrust combined bearing

[0046] 17 Rear bearing seat

[0047] 18 Radial bearings

[0048] 19 Front bearing seat plate

[0049] 20 Exhaust cylinder plate

[0050] 21 Hydraulic turning

[0051] 22 Manual turning

[0052] 23 Front bearing seat oil seal

[0053] 24 Rear bearing seat oil seal

[0054] 25 Instrument bracket

[0055] 26 Coupling

[0056] 27 Coupling cover

[0057] 28 Exhaust diaphragm valve DETAILED DESCRIPTION

[0058] The specific embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. These embodiments are only used to illustrate the present invention, but not to limit the present invention.

[0059] In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions 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 orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0060] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0061] Furthermore, in the description of the present invention, unless otherwise specified, “plurality” means two or more.

[0062] like Figure 1 and Figure 2 As shown in FIG. 1 , an embodiment of the supercritical ultra-high temperature single-cylinder reheat condensing steam turbine of the present invention is shown in FIG. 1 . It should be noted that in the description of the present invention, the “front” side is defined as Figure 1 On the left side of the paper, the front end is also the steam turbine end of the steam turbine (also the regulating valve end); the "back" side is Figure 1 On the right side of the paper, the rear end is also the motor end of the turbine; on the "upper" side is Figure 1 The upper side of the paper is also called the "top" side; the "lower" side is Figure 1 The lower side of the paper, the “lower” side is also called the “bottom” side.

[0063] The supercritical ultra-high temperature single-cylinder reheat condensing steam turbine of this embodiment comprises an outer cylinder 1 and a rotor 2 inserted in the outer cylinder 1, and a high-pressure flow module and a medium-low pressure flow module are arranged in sequence from front to back between the outer cylinder 1 and the rotor 2. The outer cylinder 1, the rotor 2, the high-pressure flow module and the medium-low pressure flow module constitute a single-cylinder steam turbine, and the high-pressure flow module and the medium-low pressure flow module are integrated in the same outer cylinder 1. The main steam enters the high-pressure steam inlet of the high-pressure flow module through the high-pressure main regulating combined steam valve 3, and a regulating stage 4 is provided inside the high-pressure flow module near the high-pressure steam inlet, and the regulating stage 4 is used to achieve a certain degree of enthalpy drop of the main steam. The high-pressure exhaust port of the high-pressure flow module is connected to the inlet of the reheater, and the reheater (not shown in the figure) is arranged outside the outer cylinder 1. The high-pressure exhaust port of the high-pressure flow module is opened on the outer cylinder 1, and is connected to the inlet of the reheater through a cold reheat steam pipeline, and the outlet of the reheater is connected to the steam inlet of the medium-low pressure flow module through a reheat steam pipeline and a reheat main regulating combined steam valve 5.

[0064] During operation, the main steam enters the high-pressure steam inlet of the high-pressure flow module through the high-pressure main regulating combined steam valve 3, first passes through the regulating stage 4 to achieve a certain degree of enthalpy drop of the main steam, and then does work through the flow area of ​​the high-pressure flow module; the steam that has done work in the high-pressure flow module enters the inlet of the reheater from the high-pressure exhaust port of the high-pressure flow module, and after being heated in the reheater, enters the steam inlet of the medium- and low-pressure flow module from the outlet of the reheater through the reheat main regulating combined steam valve 5, does work through the flow area of ​​the medium- and low-pressure flow module, and the steam that has done work in the medium- and low-pressure flow module finally enters the condenser.

[0065] The supercritical ultra-high temperature single-cylinder reheat condensing steam turbine of this embodiment adopts a single-cylinder layout for the first time in the same level and parameter units, integrating the high-pressure flow module and the medium-low pressure flow module into the same outer cylinder 1. Compared with the existing double-cylinder layout units, the axial span of the unit is greatly shortened, and the length of the whole unit can be shortened by 4 meters to 5 meters, and a set of middle bearing seat and support bearings and middle bearing seat accessory oil block, steam seal, etc. are saved, so that the cost of the whole machine is greatly reduced, and the manufacturing cost can be reduced by more than 25%. In addition, the unit structure is more compact, the axial space occupied by the equipment is reduced, and the cost of plant construction is also greatly reduced, and the workload of unit installation and maintenance is significantly reduced. The supercritical ultra-high temperature single-cylinder reheat condensing steam turbine of this embodiment adopts a steam inlet method of setting a regulating stage 4 at the high-pressure steam inlet of the high-pressure flow module to achieve a certain degree of enthalpy drop of the main steam, which has the advantage of high flexibility, can adapt to wide load operation requirements, and ensure that the unit remains efficient at low load or large steam extraction requirements.

[0066] In this embodiment, preferably, the high-pressure flow module realizes the main steam enthalpy drop through nozzle steam distribution, and the regulating stage 4 can include multiple nozzle groups, each nozzle group includes a plurality of nozzles, and by adjusting the number of nozzles, it can adapt to the operating requirements of different loads.

[0067] In this embodiment, preferably, the high-pressure flow module and the medium- and low-pressure flow modules are arranged in a bidirectional countercurrent form, specifically, the high-pressure flow module is arranged in a reverse direction, and the main steam entering the flow area of ​​the high-pressure flow module flows from back to front to perform work; the medium- and low-pressure flow modules are arranged in a forward direction, and the reheated steam entering the flow area of ​​the medium- and low-pressure flow modules flows from front to back to perform work, and finally enters the condenser.

[0068] The high-pressure flow module and the medium-low pressure flow module are arranged in a bidirectional counterflow form, so that the ultra-high temperature zone can be concentrated in the middle part of the unit counterflow, so that the temperature distribution of the flow area of ​​the entire rotor 2 from front to back is a high temperature zone, an ultra-high temperature zone and a low temperature zone. At the same time, through the nozzle steam distribution adjustment of the regulating stage 4, the main steam enthalpy drop is obvious, which effectively shortens the range of the ultra-high temperature zone of the high-pressure flow module. Based on this, in this embodiment, preferably, the rotor 2 includes a high temperature section 2.1, an ultra-high temperature section 2.2 and a low temperature section 2.3 connected in sequence from front to back, and the ultra-high temperature section 2.2 is located at the rear end of the high-pressure flow module and the front end of the medium-low pressure flow module, the high temperature section 2.1 is located at the front end of the high-pressure flow module, and the low temperature section 2.3 is located at the rear end of the medium-low pressure flow module. The materials of the high temperature section 2.1, the ultra-high temperature section 2.2 and the low temperature section 2.3 are determined according to the temperature distribution of the flow area where they are located. Specifically, the rotor material of the corresponding section can be selected according to the temperature distribution according to the working parameters of each section, strength assessment, brittle transition temperature requirements and rotor material cost, so as to form a three-section rotor 2. Preferably, the high temperature section 2.1 is welded with the ultra-high temperature section 2.2 to form a first weld area 2.4, and the ultra-high temperature section 2.2 is welded with the low temperature section 2.3 to form a second weld area 2.5, thereby forming a three-section welded rotor 2. In a preferred embodiment, the high temperature section 2.1 of the rotor 2 is made of medium carbon chromium molybdenum nickel vanadium steel, the ultra-high temperature section 2.2 is made of 9-12% Cr steel, and the low temperature section 2.3 is made of medium carbon chromium molybdenum nickel vanadium steel with a low brittle transition temperature, which has excellent adaptability to the bidirectional counterflow arrangement scheme of the high pressure flow module and the medium and low pressure flow module.

[0069] In this embodiment, preferably, the outer cylinder 1 includes a front cylinder 1.1 and an exhaust cylinder 1.2 which are connected to each other. The rear end of the front cylinder 1.1 is connected to the front end of the exhaust cylinder 1.2 to form an integrated outer cylinder 1. The high-pressure flow module and the medium-low pressure flow module are both arranged between the outer cylinder 1 and the rotor 2. The steam after work in the medium-low pressure flow module enters the exhaust cylinder 1.2 and finally enters the condenser. Preferably, the rear end of the front cylinder 1.1 and the front end of the exhaust cylinder 1.2 are assembled into an integrated outer cylinder 1 by vertical center-split bolts. The front cylinder 1.1 adopts a casting structure, which bears the support and sealing functions of the high-temperature zone of the unit.

[0070] See also Figure 2Preferably, the high-pressure flow module includes a high-pressure inner cylinder 6, and a plurality of high-pressure stages are arranged between the high-pressure inner cylinder 6 and the rotor 2, each high-pressure stage includes a row of stationary blades arranged on the high-pressure inner cylinder 6 and a row of moving blades arranged on the rotor 2, and a steam flow channel is provided between the high-pressure inner cylinder 6 and the front cylinder 1.1. The high-pressure steam exhaust port of the high-pressure flow module is arranged on the front cylinder 1.1 and is located at the position of the high-pressure inner cylinder 6. A high-pressure steam inlet is provided on the high-pressure inner cylinder 6, and a high-pressure main regulating combined steam valve 3 is installed on the front cylinder 1.1 and connected to the high-pressure steam inlet on the high-pressure inner cylinder 6 to introduce main steam into the high-pressure inner cylinder 6, and the regulating stage 4 is arranged in the high-pressure inner cylinder 6 near the high-pressure steam inlet. The medium-low pressure flow module includes a medium-pressure inner cylinder 7 and a plurality of stationary blade holding rings 8 arranged in sequence from front to back. A plurality of medium-pressure stages are arranged between the medium-pressure inner cylinder 7 and the rotor 2, and each medium-pressure stage includes a row of stationary blades arranged on the medium-pressure inner cylinder 7 and a row of moving blades arranged on the rotor 2; a plurality of stationary blade holding rings 8 and the rotor 2 are arranged between the plurality of stationary blade holding rings 8 and the rotor 2, and each low-pressure stage includes a row of stationary blades arranged on the stationary blade holding ring 8 and a row of moving blades arranged on the rotor 2. A steam inlet is provided on the medium-pressure inner cylinder 7, and a reheat main regulating combined steam valve 5 is installed on the front cylinder 1.1 and connected to the steam inlet on the medium-pressure inner cylinder 7 to pass reheat steam into the medium-pressure inner cylinder 7. During operation, the main steam enters the high-pressure steam inlet of the high-pressure inner cylinder 6 from the high-pressure main regulating combined steam valve 3, and after the main steam is distributed through the regulating stage 4 nozzle to achieve a certain degree of enthalpy drop, it flows from back to front in the high-pressure inner cylinder 6 to do work. The steam that has done work in each high-pressure stage flows back from front to back from the steam flow channel between the high-pressure inner cylinder 6 and the front cylinder 1.1 to the high-pressure exhaust port on the front cylinder 1.1, enters the reheater from the high-pressure exhaust port, and after being heated in the reheater, enters the medium-pressure inner cylinder 7 through the reheat main regulating combined steam valve 5 and flows from front to back in the medium-pressure inner cylinder 7 to do work, then enters the exhaust cylinder 2, and finally enters the condenser.

[0071] Preferably, a first balancing piston seal 9 is provided at the front end of the high pressure inner cylinder 6, and a second balancing piston seal 10 is provided at the rear end of the high pressure inner cylinder 6. The second balancing piston seal 10 is a high pressure steam inlet balancing piston seal. Preferably, a front seal 11 is provided in front of the first balancing piston seal 9 in the front cylinder 1.1.

[0072] Preferably, a final hollow stationary blade partition 12 is provided between the exhaust cylinder 1.2 and the rotor 2, which can effectively reduce the influence of blade water erosion. Preferably, an exhaust guide ring and a low-pressure water spray pipe assembly 13 are provided at the rear end side of the final hollow stationary blade partition 12, and the exhaust temperature can be adjusted and controlled by the low-pressure water spray device.

[0073] Preferably, a rear steam seal 14 is provided at the rear end of the exhaust cylinder 1.2.

[0074] In this embodiment, combined with Figure 1 and Figure 2, a floor-mounted sliding front bearing seat 15 is provided on the front side of the outer cylinder 1, and a radial thrust joint bearing 16 is provided in the front bearing seat 15. A fixed rear bearing seat 17 is provided at the rear end of the outer cylinder 1, and a radial bearing 18 is provided in the rear bearing seat 17. The front and rear ends of the rotor 2 are supported by the radial thrust joint bearing 16 and the radial bearing 18 respectively. The double-pivot, long-span shaft system design is adopted, and the span of the rotor 2 is 6.5 meters. Through the calculation and analysis of the dynamic performance of the shaft system, the rotor structure is optimized, which can make the rotor have stronger anti-interference ability and better stability, ensuring the safe and reliable operation of the unit; based on the disturbance amplitude of the long shaft system rotor during operation, the radial clearance setting is optimized at the vibration-sensitive point, which can ensure the unit's efficiency while ensuring the unit's reliable operation; in addition, the single rotor arrangement can greatly reduce the workload of on-site installation and centering, and also greatly improve the reliability of the rotor's centering.

[0075] In this embodiment, the exhaust cylinder 1.2 is supported on the exhaust cylinder platen 20. A transverse key is provided between the exhaust cylinder platen 20 and the supporting skirt of the exhaust cylinder 1.2, which serves as the absolute dead point of thermal expansion of the entire unit and pushes the unit to thermally expand toward the front end. The rear bearing seat 17 is provided on the outer side of the exhaust volute of the exhaust cylinder 1.2. In order to improve the supporting stiffness of the rear bearing seat 17, part of the rear bearing seat 17 is supported on the foundation. The front bearing seat 15 is slidably provided on the front bearing seat platen 19. The front cylinder 1.1 is supported on the front bearing seat 15 through the front cat claws, and the free expansion of the outer cylinder 1 is realized through the push-pull structure of the lower half cat claws. The radial thrust joint bearing 16 in the front bearing seat 15 serves as the relative dead point of the expansion of the rotor 2. When the unit thermally expands toward the front end, the front bearing seat 15 is pushed to slide freely on the front bearing seat platen 19. In order to reduce sliding friction, a self-lubricating alloy plate is provided between the front bearing seat 15 and the front bearing seat platen 19. In addition, a hydraulic winch 21 and a manual winch 22 are arranged in the front bearing seat 15 .

[0076] Preferably, a front bearing seat oil seal 23 is provided at the rear end of the front bearing seat 15, and a rear bearing seat oil seal 24 is provided at the front and rear ends of the rear bearing seat 17. The radial thrust joint bearing 16 and the radial bearing 18 are both equipped with high-pressure jacking oil, which is added during the unit cranking and turbine start-up and shutdown to lift the rotor 2 and reduce the friction between the rotor 2 and the bearing.

[0077] In this embodiment, an instrument bracket 25 and a coupling 26 are provided at the rear end of the rotor 2, a coupling cover 27 is connected to the rear end of the exhaust cylinder 1.2, and an exhaust diaphragm valve 28 is provided at the top of the exhaust cylinder 1.2.

[0078] The supercritical ultra-high temperature single-cylinder reheat condensing steam turbine of this embodiment is provided with two main steam lines and one reheat steam line. The valve steam distribution form is preferably that the high-pressure main regulating combined steam valve 3 is provided with two groups, and the reheat main regulating combined steam valve 5 is provided with one group. Among them, the two groups of high-pressure main regulating combined steam valves 3 are arranged on both sides of the outer cylinder 1 respectively, and each group of high-pressure main regulating combined steam valves 3 includes a high-pressure main steam valve and two high-pressure regulating steam valves, and each high-pressure regulating steam valve is connected to the high-pressure steam inlet of the high-pressure flow module. Preferably, the four high-pressure regulating steam valves correspond to the four-stage nozzle groups in sections, and the steam inlet mode can be flexibly switched to adapt to the variable working conditions and wide load operation range requirements of the unit. A group of reheat main regulating combined steam valves 5 is arranged on one side of the outer cylinder 1 (such as the left or right side), which can be flexibly arranged according to the requirements of the on-site installation space. The reheat main regulating combined steam valve 5 includes a reheat main steam valve and a reheat regulating steam valve, and the reheat regulating steam valve is connected to the steam inlet of the medium and low pressure flow module.

[0079] The supercritical ultra-high temperature single-cylinder reheat condensing steam turbine of this embodiment has an applicable power level of 135MW-175MW, an applicable steam parameter pressure of 22.2MPa-24.2MPa, and a temperature range of 565℃-600℃. The unit speed can be set to 3000r / min or 3600r / min as required. The supercritical ultra-high temperature single-cylinder reheat condensing steam turbine of this embodiment has the characteristics of compact structure, small footprint, convenient maintenance, low investment and operation cost, and short construction period.

[0080] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A supercritical ultra-high temperature single-cylinder reheat condensing steam turbine, characterized in that: The invention comprises an outer cylinder (1) and a rotor (2) inserted into the outer cylinder (1); a high-pressure flow module and a medium- and low-pressure flow module are arranged in sequence from front to back between the outer cylinder (1) and the rotor (2); main steam enters the high-pressure steam inlet of the high-pressure flow module through a high-pressure main regulating combined steam valve (3); a regulating stage (4) for achieving the main steam enthalpy drop is arranged inside the high-pressure flow module near the high-pressure steam inlet; a high-pressure steam exhaust port of the high-pressure flow module is connected to the inlet of a reheater; and the outlet of the reheater is connected to the steam inlet of the medium- and low-pressure flow module through a reheat main regulating combined steam valve (5).

2. The supercritical ultra-high temperature single-cylinder reheat condensing steam turbine according to claim 1, characterized in that: The high-pressure flow module achieves the main steam enthalpy drop by distributing steam through a nozzle.

3. The supercritical ultra-high temperature single-cylinder reheat condensing steam turbine according to claim 1 or 2, characterized in that: The high-pressure flow-through module and the medium- and low-pressure flow-through module are arranged in a bidirectional counter-flow form.

4. The supercritical ultra-high temperature single-cylinder reheat condensing steam turbine according to claim 1, characterized in that: The high-pressure flow module comprises a high-pressure inner cylinder (6), and the front end and the rear end of the high-pressure inner cylinder (6) are respectively provided with a first balance piston steam seal (9) and a second balance piston steam seal (10); the medium- and low-pressure flow module comprises a medium-pressure inner cylinder (7) and a plurality of stationary blade holding rings (8) arranged in sequence from front to back.

5. The supercritical ultra-high temperature single-cylinder reheat condensing steam turbine according to claim 3, characterized in that: The rotor (2) comprises a high temperature section (2.1), an ultra-high temperature section (2.2) and a low temperature section (2.3) which are sequentially connected from front to back, the ultra-high temperature section (2.2) being located at the rear end of the high pressure flow module and the front end of the medium and low pressure flow module, and the materials of the high temperature section (2.1), the ultra-high temperature section (2.2) and the low temperature section (2.3) are respectively determined according to the temperature distribution of the flow regions in which they are located.

6. The supercritical ultra-high temperature single-cylinder reheat condensing steam turbine according to claim 5, characterized in that: The high temperature section (2.1) is welded to the ultra-high temperature section (2.2), and the ultra-high temperature section (2.2) is welded to the low temperature section (2.3).

7. The supercritical ultra-high temperature single-cylinder reheat condensing steam turbine according to claim 1, characterized in that: The outer cylinder (1) comprises a front cylinder (1.1) and an exhaust cylinder (1.2) which are connected to each other, and the rear end of the front cylinder (1.1) is connected to the front end of the exhaust cylinder (1.2) to form an integrated outer cylinder (1).

8. The supercritical ultra-high temperature single-cylinder reheat condensing steam turbine according to claim 7, characterized in that: A final-stage hollow stationary blade large partition (12) is provided between the exhaust cylinder (1.2) and the rotor (2).

9. The supercritical ultra-high temperature single-cylinder reheat condensing steam turbine according to claim 1, characterized in that: A floor-mounted sliding front bearing seat (15) is provided at the front side of the outer cylinder (1), a radial thrust combined bearing (16) is provided inside the front bearing seat (15), a fixed rear bearing seat (17) is provided at the rear end of the outer cylinder (1), a radial bearing (18) is provided inside the rear bearing seat (17), and the front end and rear end of the rotor (2) are supported by the radial thrust combined bearing (16) and the radial bearing (18), respectively.

10. The supercritical ultra-high temperature single-cylinder reheat condensing steam turbine according to claim 1, characterized in that: The high-pressure main regulating combined steam valve (3) is provided with two groups, and the two groups of the high-pressure main regulating combined steam valve (3) are respectively arranged on both sides of the outer cylinder (1), and each group of the high-pressure main regulating combined steam valve (3) includes a high-pressure main steam valve and two high-pressure regulating steam valves, and each of the high-pressure regulating steam valves is connected to the high-pressure steam inlet of the high-pressure flow module.

11. The supercritical ultra-high temperature single-cylinder reheat condensing steam turbine according to claim 1, characterized in that: The reheat main regulating combined steam valve (5) is provided with a group. The reheat main regulating combined steam valve (5) is arranged on one side of the outer cylinder (1). The reheat main regulating combined steam valve (5) comprises a reheat main steam valve and a reheat regulating steam valve. The reheat regulating steam valve is connected to the steam inlet of the medium and low pressure flow module.

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