Integral tooth type steam turbine system

Abstract

The invention relates to the technical field of low-pressure waste heat recovery, in particular to an integral tooth type steam turbine system which comprises a reduction gearbox, a high-pressure-stage turbine unit and a low-pressure-stage turbine unit, the high-pressure-stage turbine unit comprises a high-pressure cylinder and a high-pressure cylinder impeller, and the high-pressure cylinder impeller comprises a first wheel disc and a plurality of first moving blades; the multiple first moving blades and the multiple first nozzle blades are alternately matched in the radial direction to form a first airflow channel for steam expansion flowing in the high-pressure cylinder; the low-pressure-stage turbine unit comprises a low-pressure cylinder and a low-pressure cylinder impeller, the low-pressure cylinder impeller comprises a second wheel disc and a plurality of second moving blades, and the second moving blades are distributed on the second wheel disc in the circumferential direction; the multiple second moving blades are matched with the multiple second nozzles in the axial direction so as to form a second airflow channel for steam in the low-pressure cylinder to expand and flow. And the first airflow channel is communicated with the second airflow channel through an interstage pipe. The problem that an existing steam turbine is not suitable for waste heat recovery of steam of different grades is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of low - pressure waste heat recovery, and particularly to an integral tooth type steam turbine system. Background Art

[0002] Currently, in many industries such as iron and steel metallurgy, chemical refining, photovoltaic glass, spraying and casting, and new energy battery materials, a large amount of heat and electricity are often consumed, and at the same time, a large amount of by - product low - pressure steam is continuously generated. These by - product low - pressure steams generally have a small flow rate, low temperature and pressure, and it is difficult to recover and generate electricity using large - scale steam turbines in conventional thermal power plants. Moreover, in such low - pressure steam scenarios, due to their relation to the technological process, the parameters of the low - pressure steam produced by each manufacturer and even in different technological process sections of the same manufacturer are often different, which also poses a great challenge to the design of waste heat recovery equipment.

[0003] For such low - flow and low - pressure steam waste heat resources, currently, multi - stage axial - flow small steam turbines developed based on conventional thermal power steam turbine technology are usually used for recovery and power generation. However, conventional low - speed steam turbines often have low efficiency, large size, and it is difficult to adapt to different steam flow rates and parameters through simple modularization. The scalability of the stage arrangement and cylinder structure is very poor, and in many cases, performance has to be sacrificed for the forced borrowing of the unit. When there are different grades of steam in the plant area, using conventional steam turbines requires multiple machine configurations, which will additionally increase the land occupation and investment.

[0004] In addition, the power generation of these low - pressure steam waste heat scenarios is often only within the MW level, and there is also a heating demand in some technological processes or in winter. Conventional MW - level small steam turbines are also difficult to take into account the heating demand. Summary of the Invention

[0005] In order to solve the problem that the existing steam turbines are not suitable for the waste heat recovery of different grades of steam, the purpose of the present invention is to provide an integral tooth type steam turbine system.

[0006] To achieve the above - mentioned purpose, the technical solution of the present invention is as follows.

[0007] The present invention provides an integral tooth type steam turbine system, including a speed reducer and a high - pressure stage steam turbine unit and a low - pressure stage steam turbine unit connected to both ends of the speed reducer.

[0008] The high - pressure stage steam turbine unit includes:

[0009] A high - pressure cylinder having a plurality of first nozzle blades; and

[0010] The high-pressure cylinder impeller includes a first disk and a plurality of first moving blades. The plurality of first moving blades are radially arranged on the first disk; the plurality of first moving blades and a plurality of first nozzle blades are radially alternately matched to form a first gas flow channel for the steam to expand and flow in the high-pressure cylinder;

[0011] The low-pressure stage turbine unit includes:

[0012] A low-pressure cylinder having a plurality of second nozzles; and

[0013] A low-pressure cylinder impeller includes a second disk and a plurality of second moving blades. The plurality of second moving blades are circumferentially arranged on the second disk; the plurality of second moving blades and the plurality of second nozzles are axially matched to form a second gas flow channel for the steam to expand and flow in the low-pressure cylinder;

[0014] The first gas flow channel and the second gas flow channel are communicated through an inter-stage pipe.

[0015] In a preferred embodiment, the high-pressure cylinder has a first steam inlet section and a first steam exhaust section; the first steam inlet section is axially matched with the first disk; the outer edge of the first disk is disposed within the first steam exhaust section.

[0016] In a preferred embodiment, a plurality of the first nozzle blades are radially fixed to the inner wall of the first steam exhaust section; a plurality of the first moving blades are all disposed within the first steam exhaust section and fixedly connected to the first disk.

[0017] In a preferred embodiment, an exhaust housing is fixed to the outlet end of the first steam exhaust section, and the exhaust housing is fixedly connected to one end of the inter-stage pipe.

[0018] In a preferred embodiment, the outer edge of the low-pressure cylinder has a second steam inlet section and a second steam exhaust section, and they are communicated with each other; the outer edge of the second disk is disposed within the second steam exhaust section;

[0019] A plurality of the second nozzles are all circumferentially fixedly installed within the second steam exhaust section.

[0020] In a preferred embodiment, an inlet housing is fixed to the inlet end of the second steam inlet section, and the inlet housing is fixedly connected to the other end of the inter-stage pipe.

[0021] In a preferred embodiment, the inter-stage pipe is provided with an adjustable bypass valve.

[0022] In a preferred embodiment, the adjustable bypass valve is an inter-stage extraction valve or an inter-stage supplementary steam valve;

[0023] The inter-stage extraction valve is connected to an external heat supply system; the inter-stage supplementary steam valve is connected to an external low-parameter steam system. The adjustable bypass valve can be set as an inter-stage extraction valve or an inter-stage supplementary steam valve according to the needs of the application scenario.

[0024] In a preferred embodiment, the speed reducer has a high-speed shaft, the high-speed shaft has two extending ends, and the two extending ends are respectively connected to the high-pressure cylinder impeller and the low-pressure cylinder impeller through face gears;

[0025] As steam enters the first gas flow channel in the high-pressure cylinder and expands to do work, it drives the rotation of the high-pressure cylinder impeller and the high-speed shaft of the speed reducer;

[0026] As steam enters the second gas flow channel in the low-pressure cylinder and expands to do work, it drives the rotation of the low-pressure cylinder impeller and the high-speed shaft of the speed reducer.

[0027] In a preferred embodiment, the speed reducer has a low-speed shaft, and the low-speed shaft is connected to the generator shaft through a coupling.

[0028] Advantages of the present invention:

[0029] 1. The overall toothed steam turbine system provided by the present invention has fewer stages, is compact in size, occupies a small area, and is suitable for waste heat recovery of by-product low-pressure steam.

[0030] 2. By adjusting the height and number of stages of the first moving blades on the high-pressure cylinder impeller, the present invention can flexibly match the steam inlet parameters of the high-pressure cylinder and is easy to implement modular design.

[0031] 3. By axially extending the second nozzle shroud to cover the top of the impeller to form a small clearance at the top of the low-pressure cylinder impeller, the present invention can significantly reduce the leakage loss at the top of the low-pressure cylinder impeller.

[0032] 4. The overall toothed steam turbine system provided by the present invention can adapt to scenarios with different grades of steam demand through inter-stage pipe extraction or supplementary steam, realizing the cascade utilization of steam waste heat and having higher energy efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic structural diagram of an overall toothed steam turbine system provided by an embodiment of the present invention.

[0034] Figure 2 is Figure 1 a schematic structural diagram of part A in

[0035] Figure 3 is Figure 1 a schematic structural diagram of part B in

[0036] Figure 4It is a schematic diagram of Application Mode 1 of the integral tooth type steam turbine system provided by an embodiment of the present invention.

[0037] Figure 5 It is a schematic diagram of Application Mode 2 of the integral tooth type steam turbine system provided by an embodiment of the present invention.

[0038] Figure 6 It is a schematic diagram of Application Mode 3 of the integral tooth type steam turbine system provided by an embodiment of the present invention.

[0039] In the figure, 1 is a speed reducer;

[0040] 2 is a high-pressure stage turbine unit; 21 is a high-pressure cylinder; 211 is a first nozzle vane; 212 is a first steam inlet section; 213 is a first exhaust section; 22 is a high-pressure cylinder impeller; 221 is a first disk; 222 is a first moving blade; 23 is an exhaust casing;

[0041] 3 is a low-pressure stage turbine unit; 31 is a low-pressure cylinder; 311 is a second nozzle; 312 is a second steam inlet section; 313 is a second exhaust section; 32 is a low-pressure cylinder impeller; 321 is a second disk; 322 is a second moving blade; 33 is an inlet casing;

[0042] 4 is an inter-stage pipe; 41 is an adjustable bypass valve. 5 is a generator; 6 is a waste heat boiler; 7 is a steam turbine condenser; 8 is a cooling tower. Detailed Embodiment

[0043] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0044] Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0045] Currently, in many industries such as iron and steel metallurgy, chemical refining, photovoltaic glass, spraying and casting, and new energy battery materials, while consuming a large amount of heat and electricity, a large amount of by-product low-pressure steam is also continuously generated. Generally, the flow rate of this by-product low-pressure steam is small, and the temperature and pressure are not high, making it difficult to recover and generate electricity using large steam turbines in conventional thermal power plants. Moreover, in such low-pressure steam scenarios, due to their association with the process flow, the parameters of the low-pressure steam produced by each manufacturer and even by the same manufacturer in different process flow segments often vary, which also poses a major challenge to the design of waste heat recovery equipment.

[0046] For such low-flow and low-pressure steam waste heat resources, a multi-stage axial-flow small steam turbine developed based on conventional thermal power steam turbine technology is usually used for recovery and power generation at present. However, conventional low-speed steam turbines often have low efficiency, large size, and it is difficult to adapt to different steam flow rates and parameters through simple modularization. The scalability of the stage arrangement and cylinder structure is very poor, and in many cases, performance has to be sacrificed for the forced borrowing of the unit.

[0047] Based on this, the embodiment of the present invention provides an integral toothed steam turbine system, which has fewer stages, is compact in size, occupies a small area, and is suitable for waste heat recovery of by-product low-pressure steam. Moreover, by adjusting the height and number of stages of the first moving blades on the high-pressure cylinder impeller, the steam inlet parameters of the high-pressure cylinder can be flexibly matched, and modular design is easily achieved. By axially extending the second nozzle shroud to cover the top of the impeller, a small clearance at the top of the low-pressure cylinder impeller is formed, which can significantly reduce the leakage loss at the top of the low-pressure cylinder impeller. The integral toothed steam turbine system provided by the embodiment of the present invention can adapt to scenarios with different grades of steam demand through inter-stage pipe steam extraction or supplementary steam, realizing the cascade utilization of steam waste heat and higher energy efficiency.

[0048] The integral toothed steam turbine system provided by the present invention will be described in detail below.

[0049] Please refer to Figure 1 , an integral toothed steam turbine system, including a speed reducer 1 and a high-pressure stage turbine unit 2 and a low-pressure stage turbine unit 3 connected to both ends of the speed reducer 1. In the embodiment of the present invention, by integrating the high-pressure stage turbine unit 2 and the low-pressure stage turbine unit 3 on the speed reducer, the high-pressure cylinder impeller 22 on the high-pressure stage turbine unit 2 and the low-pressure cylinder impeller 32 on the low-pressure stage turbine unit 3 are respectively installed at both ends of the high-speed pinion shaft of the speed reducer, forming a high-speed shaft double-cantilever structure. The low-speed gear shaft of the speed reducer is connected to the generator 5 through a coupling. Compared with the conventional steam turbine system, the embodiment has fewer stages, is compact in size, occupies a small area, and is suitable for waste heat recovery of by-product low-pressure steam.

[0050] As Figure 1 and Figure 2 , the high-pressure stage turbine unit 2 includes a high-pressure cylinder 21 and a high-pressure cylinder impeller 22. The high-pressure cylinder 21 has a plurality of first nozzle blades 211; the high-pressure cylinder impeller 22 includes a first disk 221 and a plurality of first moving blades 222, and the plurality of first moving blades 222 are radially arranged on the first disk 221; the plurality of first moving blades 222 and the plurality of first nozzle blades 211 are radially alternately matched to form a first gas flow channel for steam expansion flow in the high-pressure cylinder 21.

[0051] Since multiple first nozzle vanes 211 are arranged radially on one side of the first wheel disc 221 and are arranged radially staggered with multiple first moving blades 222, the number of stages arranged radially and the blade height in the axial direction of the first nozzle vanes 211 and the first moving blades 222 can be adjusted according to the needs of different application scenarios, so as to facilitate adapting to the steam pressure and flow rate requirements of different scenarios. By modular matching design, a fast-variant unit is realized. At the same time, the high-pressure cylinder housing can remain unchanged, enhancing the flexibility of the unit.

[0052] In this embodiment, the high-pressure cylinder impeller 22 adopts an integral wheel disc, and the first moving blades 222 are arranged radially on the first wheel disc 221, which can better meet the requirements of small volume flow rate and narrow flow path in the high-pressure stage. At the same time, it is also convenient to increase the number of stages radially on a single wheel disc to adapt to different inlet parameters; the first nozzle vanes 211 of the high-pressure cylinder 21 are arranged on the inlet partition plate and axially cooperate with the integral first wheel disc 221 to form the first air flow channel in the high-pressure stage, which not only shortens the axial dimension of the high-pressure stage but also is convenient for installation and disassembly.

[0053] Such as Figure 1 and Figure 3 , the low-pressure stage turbine unit 3 includes a low-pressure cylinder 31 and a low-pressure cylinder impeller 32. The low-pressure cylinder 31 has multiple second nozzles 311; the low-pressure cylinder impeller 32 includes a second wheel disc 321 and multiple second moving blades 322, and the multiple second moving blades 322 are arranged circumferentially on the second wheel disc 321; the multiple second moving blades 322 are axially matched with the multiple second nozzles 311 to form a second air flow channel for the steam to expand and flow in the low-pressure cylinder 31.

[0054] In this embodiment, the second nozzles 311 and the second moving blades 322 arranged in an axial flow manner are adopted in the low-pressure cylinder, which is different from the arrangement method in the high-pressure cylinder 21. Since the steam pressure in the low-pressure cylinder is low and the volume flow rate is relatively large, the second moving blades 322 without crown integral wheel discs and the integrally assembled second nozzles 311 are adopted. The top shroud of the second nozzle 311 extends axially, covers the top of the second moving blade 322 after axially assembling with the second moving blade 322, and forms a small tip clearance with the top of the second moving blade 322. The tip clearance of the low-pressure cylinder impeller 32 is controlled at 0.5 - 1.0 mm according to different parameter conditions to reduce the tip leakage loss of the low-pressure cylinder impeller 32. Since the low-pressure cylinder impeller 32 is designed without a crown, the low-pressure cylinder impeller 32 can be integrally milled, which is convenient for processing; by the way that the shroud of the second nozzle 311 extends to form a small clearance at the top of the low-pressure cylinder impeller 32, the tip leakage loss of the low-pressure cylinder impeller 32 can be significantly reduced.

[0055] Such as Figure 1, the first gas flow channel and the second gas flow channel are connected through the inter-stage pipe 4. Here, the high-pressure cylinder 21 and the low-pressure cylinder 31 are connected by the inter-stage pipe 4. Of course, in other embodiments, elastic components such as bellows can be provided on the inter-stage pipe 4 to adapt to thermal deformation. In addition, the inter-stage pipe 4 can cooperate with the integral toothed steam turbine system to achieve modular application configurations in different scenarios, such as Figures 4 to 6 , for example, in the scenario of extraction steam application, an inter-stage extraction steam valve can be set to extract part of the steam from the exhaust steam of the high-pressure cylinder and supply it to the next process section or meet the heating demand in winter; while for the scenario of recycling steam with different parameters, a supplementary steam valve can be set to supply steam to the low-pressure cylinder.

[0056] Such as Figure 2 , in a preferred embodiment, the high-pressure cylinder 21 has a first steam inlet section 212 and a first steam exhaust section 213; the first steam inlet section 212 is axially matched with the first disk 221; the outer edge of the first disk 221 is arranged inside the first steam exhaust section 213. Specifically, the first steam inlet section 212 has a high-pressure cylinder steam inlet. The steam generated by the waste heat boiler or the process section upstream enters the high-pressure cylinder steam inlet axially from the connecting pipe. Among them, the first steam exhaust section 213 is provided with a high-pressure cylinder diaphragm, and a plurality of first nozzle blades 211 are arranged radially on the high-pressure cylinder diaphragm. A plurality of first moving blades 222 are arranged radially on the first disk 221. Since the outer edge of the first disk 221 is arranged inside the first steam exhaust section 213, by arranging a plurality of first nozzle blades 211 and a plurality of first moving blades 222 in a radially staggered manner, a first gas flow channel flowing out radially is formed in the first steam exhaust section 213.

[0057] In a preferred embodiment, a plurality of first nozzle blades 211 are fixed radially to the inner wall of the first steam exhaust section 213; a plurality of first moving blades 222 are all arranged inside the first steam exhaust section 213 and fixedly connected to the first disk 221. Preferably, the gap between the high-pressure cylinder diaphragm and the first moving blade 222 is smaller than the width of the first moving blade 222; the gap between the first disk 221 and the first nozzle blade 211 is smaller than the width of the first nozzle blade 211. Thus, the first moving blade 222 and the first nozzle blade 211 have an overlapping part in the radial direction, forming a first gas flow channel with a Z-shaped trend arranged radially.

[0058] Such as Figure 1 , in a preferred embodiment, an exhaust housing 23 is fixed at the outlet end of the first steam exhaust section 213, and the exhaust housing 23 is fixedly connected to one end of the inter-stage pipe 4. The exhaust housing of the high-pressure cylinder 23 is fixed on the housing at one end of the high-speed shaft of the reduction gearbox 1 by bolts. The size of the exhaust housing gradually increases in the steam discharge direction, so that the steam flow rate can be slowed down, and the steam can enter the second gas flow channel through the inter-stage pipe 4.

[0059] Such as Figure 3, in a preferred embodiment, the outer edge of the low-pressure cylinder 31 has a second steam inlet section 312 and a second steam exhaust section 313, which are interconnected; the outer edge of the second disk 321 is disposed within the second steam exhaust section 313; and a plurality of second nozzles 311 are fixedly installed circumferentially within the second steam exhaust section 313. Among them, the second steam inlet section 312 and the second steam exhaust section 313 are arranged axially. The plurality of second nozzles 311 are arranged between the second steam inlet section 312 and the second steam exhaust section 313. As the steam enters the second gas flow channel, due to the axial arrangement of the second nozzles 311 and the second moving blades 322, the steam entering the second gas flow channel expands and does work to drive the rotation of the low-pressure cylinder impeller to output power, and drives the generator to generate electricity through a speed reducer.

[0060] In a preferred embodiment, the second steam exhaust section 313 of the low-pressure cylinder 31 includes an outer cylinder, an inner shroud, and a flow guiding rib plate. The front and rear flange end faces of the outer cylinder are used to connect to the intake housing and the exhaust pipe of the low-pressure cylinder. The inner shroud is a semi-elliptical shroud, which is both to protect the high-speed shaft end and can guide the exhaust of the last-stage moving blade. The rib plate integrates the inner shroud and the outer cylinder.

[0061] In a preferred embodiment, a steam inlet housing 33 is fixed at the inlet end of the second steam inlet section 312, and the steam inlet housing 33 is fixedly connected to the other end of the inter-stage pipe 4. The steam inlet housing 33 of the low-pressure cylinder is fixed to the housing at the other end of the high-speed shaft of the speed reducer 1 by bolts. The second nozzles 311 of the low-pressure cylinder are of an integral structure and are fixed to the intake housing of the low-pressure cylinder by bolts.

[0062] In a preferred embodiment, the inter-stage pipe 4 is provided with an adjustable bypass valve 41. Preferably, the adjustable bypass valve 41 is an inter-stage extraction valve or an inter-stage supplementary steam valve; the inter-stage extraction valve is connected to an external heating system; the inter-stage supplementary steam valve is connected to an external low-parameter steam system. For example, when the high-pressure stage and the low-pressure stage are connected by an inter-stage pipe and an adjustable bypass valve 41 is provided, it can act as a low-pressure supplementary steam or extraction according to on-site requirements. When there are two different-pressure steams on site, the high-pressure steam enters the unit from the turbine inlet and drives the turbine to do work; the low-pressure steam is supplemented into the inter-stage pipe through the bypass valve and enters the low-pressure stage to do work after mixing with the high-pressure stage exhaust. When the on-site process requires low-pressure steam, the bypass valve acts as an extraction valve, and the extraction requirement is met by controlling the opening. The low-pressure extraction steam can be used as a process flow or for heating. Compared with the traditional method using a pressure reducing valve, this steam is supplied to the downstream after doing work in the high-pressure cylinder, realizing cascade utilization and higher energy efficiency.

[0063] In a preferred embodiment, the speed reducer 1 has a high-speed shaft. The high-speed shaft has two protruding ends extending outward from the bearing, and the protruding ends on both sides of the high-speed shaft are respectively connected to the high-pressure cylinder impeller 22 and the low-pressure cylinder impeller 32 through end faces teeth; and a fastener is threadedly connected to the distal end of the high-speed shaft. The fastener is a tension bolt. As the tension bolt is screwed towards the corresponding high-pressure cylinder impeller 22 and low-pressure cylinder impeller 32, the protruding ends on both sides of the high-speed shaft are respectively connected to the high-pressure cylinder impeller 22 and the low-pressure cylinder impeller 32 through end faces teeth and form an integral body. As steam enters the first gas flow channel in the high-pressure cylinder 21 to expand and do work, it drives the rotation of the high-pressure cylinder impeller 22 and the high-speed shaft of the speed reducer 1; as steam enters the second gas flow channel in the low-pressure cylinder 31 to expand and do work, it drives the rotation of the low-pressure cylinder impeller 32 and the high-speed shaft of the speed reducer 1. The speed reducer 1 has a low-speed shaft, and the low-speed shaft is connected to the generator through a coupling. In the embodiment of the present invention, the high-speed shaft of the speed reducer has a double-ended protruding structure, and the first disk of the high-pressure cylinder and the second disk of the low-pressure cylinder are respectively installed in a cantilevered manner at both ends; the low-speed shaft protrudes from one side and is connected to the generator. The specific structure of the speed reducer 1 is prior art and will not be elaborated here.

[0064] In the embodiment of the present invention, the exhaust housing 23 of the high-pressure cylinder is fixed to the housing at one end of the high-speed shaft of the speed reducer 1 through bolts. The high-pressure cylinder impeller 22 is fixed to the shaft head at one end of the high-speed shaft of the speed reducer 1 through end faces teeth and tension bolts. The steam inlet housing of the high-pressure cylinder is axially fixed to the exhaust housing 23 of the high-pressure cylinder through bolts, and at the same time, it is ensured that the first nozzle blades on the steam inlet housing of the high-pressure cylinder and the first moving blades on the high-pressure cylinder impeller 22 are radially staggered and matched to form the first gas flow channel for the steam expansion flow in the high-pressure cylinder.

[0065] The steam discharged from the last-stage blades of the high-pressure cylinder impeller 22 is collected by the exhaust housing 23 of the high-pressure cylinder and enters the steam inlet housing 33 of the low-pressure cylinder through the inter-stage pipe 4. The steam inlet housing 33 of the low-pressure cylinder is also fixed to the housing at the other end of the high-speed shaft of the speed reducer 1 through bolts. The second nozzle 311 of the low-pressure cylinder is an integral structure and is fixed to the steam inlet housing 33 of the low-pressure cylinder through bolts; the low-pressure cylinder impeller 32 is also installed at the other end of the high-speed shaft of the speed reducer 1 through end faces teeth and tension bolts.

[0066] An inter-stage extraction valve / inter-stage make-up valve can be installed on the inter-stage pipe 4 for scenarios of combined heat and power supply or dual-pressure air make-up.

[0067] The working process of the integral tooth type steam turbine system provided by an embodiment of the present invention:

[0068] Steam generated upstream through the waste heat boiler or the process section axially enters the steam inlet of the high-pressure cylinder through the connecting pipe, and then expands and does work through the flow passage stage composed of the first nozzle blade and the first moving blade of the high-pressure cylinder, driving the rotation of the high-pressure cylinder impeller 22 to output power. After the exhaust steam of the high-pressure cylinder is collected by the exhaust steam shell 23 of the high-pressure cylinder, it enters the low-pressure cylinder 31 through the inter-stage pipe 4, and successively flows through the second nozzle 311 of the low-pressure cylinder and the second moving blade 322 of the low-pressure cylinder to expand and do work, driving the rotation of the low-pressure cylinder impeller 32 to output power. The high-pressure cylinder impeller 22 and the low-pressure cylinder impeller 32 are installed at both ends of the high-speed shaft of the speed reducer 1, and jointly drive the rotation of the high-speed shaft of the speed reducer 1 to output power under the push of steam, and transmit the power to the low-speed shaft through gear meshing and speed reduction. The low-speed shaft of the speed reducer 1 is connected to the generator 5, thereby driving the generator 5 to generate electricity and realizing the recovery and utilization of steam waste heat.

[0069] The following specifically describes each application mode of the integral tooth type steam turbine system provided by an embodiment of the present invention as follows.

[0070] Application mode 1: Separate power generation module.

[0071] As Figure 4 , the main steam of the waste heat boiler 6 enters the steam inlet of the high-pressure stage turbine unit 2 through the turbine quick closing valve and the regulating valve, expands and does work through the first gas flow passage, driving the rotation of the high-pressure cylinder impeller 22 to output power; then the low-pressure steam enters the low-pressure stage turbine unit 3 through the inter-stage pipe 4, expands and does work through the second gas flow passage, driving the rotation of the low-pressure cylinder impeller to output power; thus driving the generator 5 to generate electricity through the speed reducer. After the steam exits the integral tooth type steam turbine system, it enters the turbine condenser 7 and realizes water circulation with the cooling tower 8, and then the condensed water returns to the waste heat boiler 6.

[0072] In Application mode 1, the upstream steam is only used for power generation recovery. At this time, no inter-stage valve is set for the whole machine module, and the inter-stage pipe only serves as the connection between the exhaust steam of the high-pressure cylinder and the inlet steam of the low-pressure cylinder.

[0073] Application mode 2: Power generation and extraction utilization module.

[0074] As Figure 5 , the main steam of the waste heat boiler 6 enters the steam inlet of the high-pressure stage turbine unit 2 through the turbine quick closing valve and the regulating valve, expands and does work through the first gas flow passage, driving the rotation of the high-pressure cylinder impeller 22 to output power. On the one hand, the low-pressure steam is extracted through the inter-stage pipe 4 for downstream processes or heating; on the other hand, the low-pressure steam enters the low-pressure stage turbine unit 3 through the inter-stage pipe 4, expands and does work through the second gas flow passage, driving the rotation of the low-pressure cylinder impeller to output power; thus driving the generator 5 to generate electricity through the speed reducer. After the steam exits the integral tooth type steam turbine system, it enters the turbine condenser 7 and realizes water circulation with the cooling tower 8, and then the condensed water returns to the waste heat boiler 6.

[0075] In Application Mode 2, the unit not only generates electricity, but also sets up extraction valves in the inter-stage pipe to extract part of the exhaust steam from the high-pressure cylinder for downstream use, for heating or process use. For the time when steam supply or heating is not required, the inter-stage valve can be controlled to close.

[0076] Application Mode 3: Dual-pressure steam supplementary power generation module.

[0077] Such as Figure 6 , the main steam of the waste heat boiler 6 enters the steam inlet of the high-pressure stage turbine unit 2 through the quick shut-off valve and regulating valve of the steam turbine, expands and does work through the first gas flow channel, and drives the high-pressure cylinder impeller 22 to rotate and output power; then the low-pressure steam enters the low-pressure stage turbine unit 3 through the inter-stage pipe 4, and the external low-pressure steam enters the low-pressure stage turbine unit 3 through the inter-stage pipe 4 to achieve inter-stage steam supplementation. The low-pressure steam expands and does work through the second gas flow channel, driving the low-pressure cylinder impeller to rotate and output power; thus, the generator 5 is driven to generate electricity through the speed reducer. After the steam exits the integral toothed steam turbine system, it enters the steam turbine condenser 7, and a water cycle is realized with the cooling tower 8, and then the condensed water returns to the waste heat boiler 6.

[0078] In Application Mode 3, for the scenario where the upstream steam may be of different pressure grades, at this time the inter-stage pipe serves as the inlet for steam supplementation of the downstream low-pressure cylinder. At this time, a steam supplementation valve is set in the inter-stage pipe of the unit, and the high-pressure steam directly enters the high-pressure cylinder inlet. After expanding and doing work in the high-pressure cylinder, it enters the low-pressure cylinder through the inter-stage pipe; the low-parameter steam passes through the steam supplementation valve on the inter-stage pipe, mixes with the high-pressure cylinder exhaust steam, and then enters the downstream low-pressure cylinder to expand and generate electricity. The exhausted steam discharged from the low-pressure cylinder returns to the condenser and condenses into water, which is pumped away by the condensate pump.

[0079] In the embodiment of the present invention, a layout of two cylinders, a high-pressure cylinder and a low-pressure cylinder, is adopted. The high-pressure stage adopts an integral disk-type radial centrifugal turbine stage, and the impeller disk is installed at one end of the high-speed shaft of the gearbox; the low-pressure stage adopts an axial flow turbine stage, and the blade disk is installed at the other end of the high-speed shaft of the gearbox. The high-pressure and low-pressure stages are connected by an inter-stage pipeline, and an adjustable bypass valve is set, which can act as a low-pressure air supplement and extraction according to on-site requirements. When there are two different-pressure steam flows on-site, the high-pressure steam enters the unit from the turbine inlet and drives the turbine to do work; the low-pressure steam is supplemented into the inter-stage pipe through the bypass valve, mixes with the high-pressure stage exhaust gas, and then enters the low-pressure stage to do work. When low-pressure steam is required for the on-site process, the bypass valve acts as an extraction valve, and the extraction requirement is met by controlling the opening. The low-pressure extraction steam can be used for process use or heating use. Compared with the traditional method using a pressure reducing valve, this steam is supplied to the downstream after doing work in the high-pressure cylinder, realizing cascade utilization and higher energy efficiency.

[0080] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. An integral gear steam turbine system, characterized in that, It includes a speed reducer (1), a high-pressure stage turbine unit (2) and a low-pressure stage turbine unit (3) connected to both ends of the speed reducer (1). The high-pressure stage turbine unit (2) includes: a high-pressure cylinder (21) having a plurality of first nozzle vanes (211); and a high-pressure cylinder impeller (22) including a first disk (221) and a plurality of first moving blades (222), the plurality of first moving blades (222) being radially arranged on the first disk (221); the plurality of first moving blades (222) and the plurality of first nozzle vanes (211) being alternately matched radially to form a first gas flow passage for steam expansion flow in the high-pressure cylinder (21). The low-pressure stage turbine unit (3) includes: a low-pressure cylinder (31) having a plurality of second nozzles (311); and a low-pressure cylinder impeller (32) including a second disk (321) and a plurality of second moving blades (322), the plurality of second moving blades (322) being circumferentially arranged on the second disk (321); the plurality of second moving blades (322) and the plurality of second nozzles (311) being axially matched to form a second gas flow passage for steam expansion flow in the low-pressure cylinder (31). The first gas flow passage is communicated with the second gas flow passage through an inter-stage pipe (4).

2. The integral tooth type steam turbine system according to claim 1, wherein The high-pressure cylinder (21) has a first steam inlet section (212) and a first steam exhaust section (213); the first steam inlet section (212) is axially matched with the first disk (221); the outer edge of the first disk (221) is arranged in the first steam exhaust section (213).

3. The integral tooth type steam turbine system according to claim 2, characterized in that The plurality of first nozzle vanes (211) are radially fixed to the inner wall of the first steam exhaust section (213); the plurality of first moving blades (222) are all arranged in the first steam exhaust section (213) and fixedly connected to the first disk (221).

4. The integral tooth type steam turbine system according to claim 1, characterized in that An exhaust housing (23) is fixed to the outlet end of the first steam exhaust section (213), and the exhaust housing (23) is fixedly connected to one end of the inter-stage pipe (4).

5. The integral gear type steam turbine system according to claim 1, wherein, The outer edge of the low-pressure cylinder (31) has a second steam inlet section (312) and a second steam exhaust section (313) which are communicated with each other; the outer edge of the second disk (321) is arranged in the second steam exhaust section (313). The plurality of second nozzles (311) are all circumferentially fixedly installed in the second steam exhaust section (313).

6. The integral gear type steam turbine system according to claim 5, characterized in that, An inlet housing (33) is fixed to the inlet end of the second steam inlet section (312), and the inlet housing (33) is fixedly connected to the other end of the inter-stage pipe (4).

7. The integral tooth type steam turbine system according to claim 1, characterized in that, The inter-stage pipe (4) is provided with an adjustable bypass valve (41).

8. The integral tooth type steam turbine system according to claim 7, characterized in that, The adjustable bypass valve (41) is an inter-stage steam extraction valve or an inter-stage steam supply valve; The inter-stage steam extraction valve is connected to an external heat supply system; the inter-stage steam supply valve is connected to an external low-parameter steam system.

9. The integral tooth type steam turbine system according to claim 1, characterized in that, The speed reducer (1) has a high-speed shaft, and the high-speed shaft has two extending ends, and the two extending ends are respectively connected to the high-pressure cylinder impeller (22) and the low-pressure cylinder impeller (32) through face gears; As steam enters the first gas flow channel in the high-pressure cylinder (21) to expand and do work, it drives the rotation of the high-pressure cylinder impeller (22) and the high-speed shaft of the speed reducer (1); As steam enters the second gas flow channel in the low-pressure cylinder (31) to expand and do work, it drives the rotation of the low-pressure cylinder impeller (32) and the high-speed shaft of the speed reducer (1).

10. The integral tooth type steam turbine system according to claim 9, characterized in that, The speed reducer (1) has a low-speed shaft, and the low-speed shaft is connected to the generator through a coupling.

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