Multi-source cooperative steam turbine with all-working-condition efficiency reconstruction and control method

Abstract

The invention relates to a multi-source cooperative steam turbine with all-working-condition efficiency reconstruction and a control method. The multi-source cooperative steam turbine comprises a multi-source cooperative steam turbine high-pressure cylinder, a multi-source cooperative steam turbine intermediate-pressure cylinder, a multi-source cooperative steam turbine intermediate-low pressure combined cylinder and a multi-source cooperative steam turbine low-pressure combined cylinder which are coaxially arranged. The gradient adaptive turbine is arranged on another shaft or coaxially arranged through a clutch, and a steam inlet of a gradient adaptive turbine cylinder is connected with a main steam output pipeline of the boiler and is provided with a gradient adaptive turbine main steam regulating valve; a steam exhaust port of the gradient adaptive turbine cylinder is divided into two paths, one path is connected to the downstream of the high-pressure regulating valve so as to lead to a steam inlet of a high-pressure cylinder of the multi-source cooperative steam turbine, the other path leads to a condenser and is provided with a gradient adaptive turbine ventilation valve, and a gradient adaptive turbine rotor is connected with a turbine generator. The steam turbine can effectively improve the circulating heat efficiency of the steam turbine under variable working conditions, and obviously improves the economy of partial load operation of a coal power unit under a novel electric power system.

Description

Technical Field

[0001] The present invention relates to the technical field of high-efficiency coal-fired power generation, and in particular to a multi-source coordinated steam turbine with full-operating efficiency reconstruction and a control method thereof. Background Art

[0002] The coal consumption of coal-fired power generation units is mainly related to factors such as turbine heat consumption, boiler efficiency, plant power consumption rate, and pipeline efficiency.

[0003] Existing coal-fired power steam turbines utilize a rigid series arrangement of steam flows for their high, medium, and low pressure cylinders, resulting in a fixed flow design. The main steam expands and produces work along a predetermined high-medium-low pressure path throughout the unit's operating range, lacking adaptive adjustment of operating parameters. Under partial load conditions, with sliding pressures in the main steam, reheat, and extraction steam pressures, the Rankine cycle's characteristics lead to a decrease in the average heat absorption temperature of the cycle as initial parameters decrease. This results in a nonlinear decrease in theoretical thermal efficiency, ultimately leading to a significant increase in coal consumption during low-load operation.

[0004] This fixed flow design restricts the thermodynamic perfection of the unit during variable load operation. The heat consumption of the turbine at 30% rated load increases by more than 16% compared with 100% rated load, making it impossible to achieve the power supply coal consumption target of no more than 15% increase in power supply coal consumption at 30% rated load compared with 100% rated load. Summary of the Invention

[0005] The purpose of the present invention is to provide a multi-source cooperative steam turbine with full-operating efficiency reconstruction to improve the cycle thermal efficiency of the steam turbine under variable operating conditions and reduce the heat consumption of the partial load steam turbine, thereby solving the above technical problems.

[0006] Another object of the present invention is to provide a control method for a multi-source coordinated steam turbine with full-operating efficiency reconstruction.

[0007] To achieve the above-mentioned objectives, the present invention provides a multi-source coordinated steam turbine with full-operating efficiency reconstruction, comprising:

[0008] The high-pressure cylinder of the multi-source coordinated steam turbine has a steam inlet connected to the main steam output pipe of the boiler and is equipped with a high-pressure regulating valve; the steam exhaust of the high-pressure cylinder of the multi-source coordinated steam turbine is connected to the reheat cold section pipe of the boiler;

[0009] The steam inlet of the intermediate pressure cylinder of the multi-source coordinated steam turbine is connected to the reheat steam output pipe of the boiler, and is equipped with an intermediate pressure cylinder steam inlet regulating valve, and its exhaust port is connected to the steam inlet of the low pressure cylinder;

[0010] The steam inlet of the multi-source coordinated steam turbine is connected to the reheat steam output pipe of the boiler, and is equipped with a medium and low pressure combined steam inlet regulating valve, and its exhaust is connected to the condenser;

[0011] The low-pressure cylinder of the multi-source coordinated steam turbine has its exhaust port connected to the condenser;

[0012] A gradient adaptive turbine comprises a gradient adaptive turbine cylinder and a gradient adaptive turbine rotor. The steam inlet of the gradient adaptive turbine cylinder is connected to the main steam output pipe of the boiler and is provided with a gradient adaptive turbine main steam regulating valve. The steam exhaust of the gradient adaptive turbine cylinder is divided into two routes, one of which is connected downstream of the high-pressure regulating valve to the steam inlet of the high-pressure cylinder of the multi-source coordinated steam turbine, and the other of which is connected to the condenser and is provided with a gradient adaptive turbine ventilation valve.

[0013] The multi-source coordinated steam turbine high-pressure cylinder, the multi-source coordinated steam turbine intermediate-pressure cylinder, the multi-source coordinated steam turbine intermediate-low pressure combined cylinder, and the multi-source coordinated steam turbine low-pressure cylinder are coaxially arranged through the multi-source coordinated steam turbine rotor and connected to the main generator;

[0014] The gradient adaptive turbine is arranged on another axis, and the gradient adaptive turbine rotor is connected to the turbine generator; or, the gradient adaptive turbine is arranged coaxially with the high-pressure cylinder of the multi-source cooperative steam turbine, and a clutch is provided between the gradient adaptive turbine rotor and the rotor of the high-pressure cylinder of the multi-source cooperative steam turbine.

[0015] Optionally, it also includes a controller; the controller is used to control the gradient adaptive turbine main steam regulating valve, high pressure regulating valve, medium pressure cylinder steam inlet regulating valve, medium and low pressure combined cylinder steam inlet regulating valve and gradient adaptive turbine ventilation valve according to the turbine load rate.

[0016] Optionally, the intermediate pressure cylinder of the multi-source cooperative steam turbine is an opposed double intermediate pressure cylinder, including a first intermediate pressure cylinder and a second intermediate pressure cylinder arranged symmetrically, and the first intermediate pressure cylinder and the second intermediate pressure cylinder are provided with parallel intermediate pressure heat recovery extraction pipes.

[0017] Optionally, the multi-source cooperative steam turbine low-pressure combined cylinder is an opposed double low-pressure cylinder, including a first low-pressure cylinder and a second low-pressure cylinder arranged symmetrically, and the first low-pressure cylinder and the second low-pressure cylinder are provided with parallel low-pressure heat recovery steam extraction pipes.

[0018] Optionally, the multi-source coordinated steam turbine rotor passes through the multi-source coordinated steam turbine high-pressure cylinder, the multi-source coordinated steam turbine intermediate-pressure cylinder, the multi-source coordinated steam turbine intermediate- and low-pressure combined cylinder, the multi-source coordinated steam turbine low-pressure cylinder, and the main generator.

[0019] Optionally, the power output end of the turbine generator is connected to the power grid of the power plant, and the power output end of the main generator is connected to the power supply grid.

[0020] Optionally, the flow area of the multi-source cooperative steam turbine intermediate pressure cylinder and the multi-source cooperative steam turbine low pressure cylinder is M% of the total flow area, and the flow area of the multi-source cooperative steam turbine intermediate and low pressure combined cylinder is N% of the total flow area, M+N=100.

[0021] To achieve the above-mentioned another object, the present invention provides a multi-source coordinated steam turbine control method for full-operating efficiency reconstruction, which is used to control the multi-source coordinated steam turbine for full-operating efficiency reconstruction described in any of the above items, comprising:

[0022] The turbine load rate is obtained in real time. When the turbine load rate is within the range of M% to 100%, the main steam regulating valve of the gradient adaptive turbine is controlled to be fully closed, the high-pressure regulating valve is controlled to be gradually opened to fully open as the turbine load percentage increases, the intermediate-pressure cylinder steam inlet regulating valve is controlled to be fully opened, and the intermediate- and low-pressure combined cylinder steam inlet regulating valves are controlled to be fully opened. The main steam is operated at sliding pressure, and the main steam pressure is the rated pressure at 100% load.

[0023] When the turbine load rate is between 0% and M%, the gradient adaptive turbine main steam regulating valve is controlled to be fully opened, the high-pressure regulating valve is controlled to be fully closed, the intermediate-pressure cylinder steam inlet regulating valve is controlled to be fully opened, and the intermediate- and low-pressure combined cylinder steam inlet regulating valve is controlled to be fully closed, so that the intermediate- and low-pressure combined cylinders operate at zero power. At M% load, the main steam pressure and the reheat steam pressure are increased to the pressure values of the rated operating conditions, thereby realizing the re-establishment of the rated values of the main and reheat pressures.

[0024] Furthermore, when the turbine load rate is higher than M%, the gradient adaptive turbine ventilation valve is controlled to open to discharge the steam in the gradient adaptive turbine cylinder to the condenser.

[0025] To achieve the above-mentioned another object, the present invention provides a multi-source coordinated steam turbine control method for full-operating efficiency reconstruction, which is used to control the multi-source coordinated steam turbine for full-operating efficiency reconstruction described in any of the above items, comprising:

[0026] The steam turbine load factor is obtained in real time. When the steam turbine load factor is within the range of M% to 100%, the clutch between the gradient adaptive turbine rotor and the high-pressure cylinder of the multi-source coordinated steam turbine is disconnected. The main steam regulating valve of the gradient adaptive turbine is controlled to be fully closed. The high-pressure regulating valve is controlled to be gradually opened to be fully open as the steam turbine load percentage increases. The steam inlet regulating valve of the intermediate-pressure cylinder is controlled to be fully opened. The steam inlet regulating valves of the intermediate- and low-pressure combined cylinders are controlled to be fully opened. The main steam is operated at sliding pressure. At 100% load, the main steam pressure is the rated pressure.

[0027] When the turbine load rate is between 0% and M%, the clutch between the gradient adaptive turbine rotor and the high-pressure cylinder of the multi-source cooperative turbine is engaged, the main steam regulating valve of the gradient adaptive turbine is controlled to be fully opened, the high-pressure regulating valve is controlled to be fully closed, the intermediate-pressure cylinder steam inlet regulating valve is controlled to be fully opened, and the intermediate- and low-pressure combined cylinder steam inlet regulating valve is controlled to be fully closed, so that the intermediate- and low-pressure combined cylinders operate at zero power. At M% load, the main steam pressure and the reheat steam pressure are increased to the pressure values of the rated operating conditions, thereby realizing the re-establishment of the rated values of the main and reheat pressures.

[0028] Furthermore, when the turbine load rate is higher than M%, the gradient adaptive turbine ventilation valve is controlled to open to discharge the steam in the gradient adaptive turbine cylinder to the condenser.

[0029] The steam turbine provided by the present invention adopts an innovative architecture of a dual-shaft arrangement of a gradient adaptive turbine and a multi-source coordinated steam turbine. The gradient adaptive turbine drives the turbine generator to operate independently, and the multi-source coordinated steam turbine drives the main generator to connect to the grid for power generation. The multi-source coordinated steam turbine adopts a combination design of a high-pressure cylinder and a variable-configuration medium- and low-pressure cylinder, wherein the variable-configuration medium- and low-pressure cylinder module is composed of a medium-pressure cylinder, a medium- and low-pressure combined cylinder, and a low-pressure cylinder. This technology achieves thermal system optimization through an original steam turbine system layout and control strategy, significantly improving key parameters such as main steam pressure, reheat steam pressure, and feed water temperature under partial load conditions. According to the Rankine cycle principle, it can effectively improve the cycle thermal efficiency of the steam turbine under variable conditions, and significantly improve the partial-load operation economy of coal-fired power units under new power systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic structural diagram of a multi-source coordinated steam turbine with full-operating efficiency reconstruction provided by the first embodiment of the present invention;

[0031] Figure 2 for Figure 1 Schematic diagram of steam path when the multi-source coordinated steam turbine is in the first operating condition;

[0032] Figure 3 for Figure 1 Schematic diagram of steam path when the multi-source coordinated steam turbine is in the second operating condition;

[0033] Figure 4 A schematic structural diagram of a multi-source coordinated steam turbine with full-operating efficiency reconstruction provided by a second embodiment of the present invention;

[0034] Figure 5 for Figure 1 The control principle block diagram of the multi-source coordinated steam turbine is shown.

[0035] In the picture:

[0036] 1. Boiler; 2. Gradient adaptive turbine main steam control valve; 3. Gradient adaptive turbine cylinder; 4. Turbine generator; 5. Gradient adaptive turbine ventilation valve; 6. High-pressure control valve; 7. Multi-source coordinated steam turbine high-pressure cylinder; 8. Intermediate-pressure cylinder steam inlet control valve; 9 Intermediate-pressure heat recovery extraction pipe; 10. Multi-source coordinated steam turbine intermediate-pressure cylinder; 11. Intermediate- and low-pressure combined cylinder steam inlet control valve; 12. Multi-source coordinated steam turbine intermediate- and low-pressure combined cylinder; 13. Low-pressure heat recovery extraction pipe; 14. Multi-source coordinated steam turbine low-pressure combined cylinder; 15. Multi-source coordinated steam turbine rotor; 16. Main generator; 17. Gradient adaptive turbine rotor; 18. Controller; 19. Clutch. DETAILED DESCRIPTION

[0037] In order to enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0038] In this article, terms such as "upper, lower, inside, outside" are established based on the positional relationships shown in the drawings. Depending on the different drawings, the corresponding positional relationships may also change accordingly. Therefore, they cannot be understood as absolute limitations on the scope of protection; moreover, relational terms such as "first" and "second" are only used to distinguish one component from another with the same name, and do not necessarily require or imply any actual relationship or order between these components.

[0039] Please refer to Figure 1 、 Figure 5 , Figure 1 A schematic structural diagram of a multi-source coordinated steam turbine with full-operating efficiency reconstruction provided by the first embodiment of the present invention; Figure 5 for Figure 1 The control principle block diagram of the multi-source coordinated steam turbine is shown.

[0040] As shown in the figure, in a specific embodiment, the multi-source cooperative steam turbine with full-operating efficiency reconstruction provided by the present invention is mainly composed of a multi-source cooperative steam turbine high-pressure cylinder 7, a multi-source cooperative steam turbine intermediate-pressure cylinder 10, a multi-source cooperative steam turbine intermediate- and low-pressure combined cylinder 12, a multi-source cooperative steam turbine low-pressure combined cylinder 14, a gradient adaptive turbine and a controller 18.

[0041] The multi-source coordinated steam turbine intermediate pressure cylinder 10, the multi-source coordinated steam turbine intermediate and low pressure combined cylinder 12, and the multi-source coordinated steam turbine low pressure cylinder 14 constitute an intermediate and low pressure cylinder module with variable area. That is to say, by conduction or cutoff, the multi-source coordinated steam turbine intermediate pressure cylinder 10, the multi-source coordinated steam turbine intermediate and low pressure combined cylinder 12, the multi-source coordinated steam turbine low pressure cylinder 14 and the multi-source coordinated steam turbine high pressure cylinder 7 and the gradient adaptive turbine can form a combination of different flow areas, so that it can adapt to different working conditions.

[0042] In this embodiment, the flow area of the multi-source cooperative steam turbine intermediate pressure cylinder 10 and the multi-source cooperative steam turbine low pressure cylinder 14 is M% of the total flow area, and the flow area of the multi-source cooperative steam turbine intermediate and low pressure combined cylinder 12 is N% of the total flow area, M+N=100.

[0043] The steam inlet of the high-pressure cylinder 7 of the multi-source cooperative steam turbine is connected to the main steam output pipe of the boiler 1, and a high-pressure regulating valve 6 is provided on the connected pipe. The steam exhaust port of the high-pressure cylinder 7 of the multi-source cooperative steam turbine is connected to the reheat cold section pipe of the boiler 1.

[0044] The intermediate pressure cylinder 10 of the multi-source cooperative steam turbine is an opposed double intermediate pressure cylinder, which has a first intermediate pressure cylinder and a second intermediate pressure cylinder arranged symmetrically. The first intermediate pressure cylinder and the second intermediate pressure cylinder are provided with parallel intermediate pressure heat recovery steam extraction pipes 9.

[0045] The steam inlet of the intermediate pressure cylinder 10 of the multi-source cooperative steam turbine is connected to the reheat steam output pipe of the boiler 1, and an intermediate pressure cylinder steam inlet regulating valve 8 is provided on the connected pipe. The steam exhaust port of the intermediate pressure cylinder 10 of the multi-source cooperative steam turbine is connected to the steam inlet of the low pressure cylinder 14.

[0046] The multi-source cooperative steam turbine low-pressure combined cylinder 14 is an opposed double low-pressure cylinder, which has a symmetrically arranged first low-pressure cylinder and a second low-pressure cylinder. The first low-pressure cylinder and the second low-pressure cylinder are provided with parallel low-pressure heat recovery steam extraction pipes 13, and their exhaust ports are connected to the condenser.

[0047] The steam inlet of the medium and low pressure combined cylinder 12 of the multi-source coordinated steam turbine is connected to the reheat steam output pipe of the boiler 1, and a medium and low pressure combined cylinder steam inlet regulating valve 11 is provided on the connected pipe, and its exhaust port is connected to the condenser;

[0048] The gradient adaptive turbine has a gradient adaptive turbine cylinder 3 and a gradient adaptive turbine rotor 17. The steam inlet of the gradient adaptive turbine cylinder 3 is connected to the main steam output pipe of the boiler 1, and a gradient adaptive turbine main steam regulating valve 2 is provided on the connected pipe; the exhaust port of the gradient adaptive turbine cylinder 3 is divided into two routes, one route is connected to the downstream of the high-pressure regulating valve 6 to lead to the steam inlet of the multi-source coordinated steam turbine high-pressure cylinder), and the other route leads to the condenser and is provided with a gradient adaptive turbine ventilation valve 5. The gradient adaptive turbine rotor 17 is connected to the turbine generator 4 to drive the turbine generator 4 to generate electricity.

[0049] The multi-source coordinated steam turbine high-pressure cylinder 7, the multi-source coordinated steam turbine intermediate-pressure cylinder 10, the multi-source coordinated steam turbine intermediate- and low-pressure combined cylinder 12, and the multi-source coordinated steam turbine low-pressure cylinder 14 are coaxially arranged through the multi-source coordinated steam turbine rotor 15 and connected to the main generator 16. In this embodiment, the multi-source coordinated steam turbine rotor 15 passes through the multi-source coordinated steam turbine high-pressure cylinder 7, the multi-source coordinated steam turbine intermediate-pressure cylinder 10, the multi-source coordinated steam turbine intermediate- and low-pressure combined cylinder 12, the multi-source coordinated steam turbine low-pressure cylinder 14, and the main generator 16 to drive the main generator 16 to generate electricity.

[0050] The power output terminal of the turbine generator 4 is connected to the power grid of the power plant, and the power output terminal of the main generator 16 is connected to the power supply grid.

[0051] The controller 18 is used to control the gradient adaptive turbine main steam regulating valve 2, the multi-source coordinated turbine high-pressure regulating valve 6, the medium-pressure cylinder steam inlet regulating valve 8, the medium- and low-pressure combined cylinder steam inlet regulating valve 11 and the gradient adaptive turbine ventilation valve 5 according to the turbine load rate.

[0052] Please refer to Figure 4 , Figure 4 A schematic structural diagram of a multi-source coordinated steam turbine with full-operating efficiency reconstruction provided by the second embodiment of the present invention.

[0053] As shown in the figure, compared with the first embodiment, the difference of this embodiment is:

[0054] The gradient adaptive turbine is coaxially arranged with the high-pressure cylinder 7 of the multi-source cooperative steam turbine, and a clutch 19 is provided between the rotor 17 of the gradient adaptive turbine and the rotor of the high-pressure cylinder 7 of the multi-source cooperative steam turbine. During use, the gradient adaptive turbine is disconnected or connected to the main generator 16 by disconnecting or engaging the clutch 19.

[0055] In this embodiment, the same parts as those in the first embodiment are given the same reference numerals, and the same text descriptions are omitted.

[0056] The above embodiment is merely a preferred solution of the present invention and is not intended to be limiting. Based on this, targeted adjustments can be made based on actual needs to achieve different implementations. For example, the multi-source coordinated steam turbine intermediate pressure cylinder 10 and the multi-source coordinated steam turbine low pressure cylinder 14 can be replaced with a single cylinder structure. Due to the numerous possible implementations, we will not provide a detailed description here.

[0057] like Figure 5 As shown, in addition to the above-mentioned multi-source coordinated steam turbine, the present invention also provides a method for controlling the above-mentioned multi-source coordinated steam turbine with full-operating efficiency reconstruction, comprising the following steps:

[0058] The turbine load rate is obtained in real time. When the turbine load rate is in the range of M%~100%, the gradient adaptive turbine main steam control valve 2 is controlled to be fully closed, and the high-pressure control valve 6 is controlled to be gradually opened to fully open as the turbine load percentage increases. The intermediate-pressure cylinder steam inlet control valve 8 is controlled to be fully opened, and the intermediate- and low-pressure combined cylinder steam inlet control valve 11 is controlled to be fully opened. The main steam operates at sliding pressure, and the main steam pressure is the rated pressure at 100% load.

[0059] like Figure 2 As shown, under this operating condition, the multi-source coordinated steam turbine high-pressure cylinder 7, the multi-source coordinated steam turbine intermediate-pressure cylinder 10, the multi-source coordinated steam turbine intermediate- and low-pressure combined cylinder 12, and the multi-source coordinated steam turbine low-pressure cylinder 14 are in working state (purple), and the gradient adaptive turbine is in zero power state (blue).

[0060] Steam path such as Figure 2 As shown by the red arrow:

[0061] The main steam enters the high-pressure cylinder 7 of the multi-source coordinated steam turbine through the high-pressure regulating valve 6 to perform work, and then returns to the reheater of the boiler 1 for heating. The reheated steam enters the intermediate-pressure cylinder 10 of the multi-source coordinated steam turbine and the intermediate- and low-pressure combined cylinder 12 of the multi-source coordinated steam turbine to perform work through the intermediate-pressure cylinder steam inlet regulating valve 8 and the intermediate- and low-pressure combined cylinder steam inlet regulating valve 11 respectively. The exhaust steam of the intermediate-pressure cylinder 10 of the multi-source coordinated steam turbine enters the low-pressure cylinder 14 of the multi-source coordinated steam turbine to perform work. The steam of the intermediate- and low-pressure combined cylinder 12 of the multi-source coordinated steam turbine is discharged to the condenser. The high-pressure cylinder 7 of the multi-source coordinated steam turbine, the intermediate-pressure cylinder 10 of the multi-source coordinated steam turbine, the intermediate- and low-pressure combined cylinder 12 of the multi-source coordinated steam turbine, and the low-pressure cylinder 14 of the multi-source coordinated steam turbine jointly drive the main generator 16 connected thereto to generate electricity, which is used to power the grid. At this time, the gradient adaptive turbine does not drive the turbine generator 4 to generate electricity.

[0062] When the turbine load rate is between 0% and M%, the gradient adaptive turbine main steam regulating valve 2 is controlled to be fully open, the high-pressure regulating valve 6 is controlled to be fully closed, the intermediate-pressure cylinder steam inlet regulating valve 8 is controlled to be fully open, and the intermediate- and low-pressure combined cylinder steam inlet regulating valve 11 is controlled to be fully closed, so that the intermediate- and low-pressure combined cylinder 12 of the multi-source coordinated steam turbine operates at zero power. At M% load, the main steam pressure and the reheat steam pressure are increased to the pressure values of the rated operating conditions, thereby realizing the re-establishment of the rated values of the main and reheat pressures.

[0063] like Figure 3 As shown, under this operating condition, the high-pressure cylinder 7 of the multi-source coordinated steam turbine does not enter the high-pressure main steam (orange), the intermediate and low-pressure combined cylinders 12 of the multi-source coordinated steam turbine are in a zero-power state (blue), and the gradient adaptive turbine, the intermediate-pressure cylinder 10 of the multi-source coordinated steam turbine, and the low-pressure cylinder 14 of the multi-source coordinated steam turbine are in a working state (purple).

[0064] Steam path such as Figure 3 As shown by the red arrow:

[0065] The main steam enters the gradient adaptive turbine cylinder 3 through the gradient adaptive turbine main steam regulating valve 2 to perform work, and the small generator 4 connected to it is used for plant electricity; the exhaust steam of the gradient adaptive turbine cylinder 3 enters the multi-source coordinated steam turbine high-pressure cylinder 7 through the high-pressure regulating valve 6. At this time, the multi-source coordinated steam turbine high-pressure cylinder 7 is only used to provide a steam path, and then returns to the reheater of the boiler 1 for heating. The reheated steam passes through the intermediate pressure cylinder steam inlet regulating valve 8 and enters the multi-source coordinated steam turbine intermediate pressure cylinder 10 to perform work. The exhaust steam of the multi-source coordinated steam turbine intermediate pressure cylinder 10 then enters the multi-source coordinated steam turbine low pressure cylinder 14 to perform work. The multi-source coordinated steam turbine intermediate pressure cylinder 10 and the multi-source coordinated steam turbine low pressure cylinder 14 jointly drive the main generator 16 connected to it to generate electricity, which is used for power supply to the grid. At this time, the multi-source coordinated steam turbine intermediate and low pressure combined cylinder 12 does not perform work and is in a zero power state.

[0066] In addition, it also includes: when the turbine load rate is higher than M%, controlling the gradient adaptive turbine ventilation valve 5 to open, and discharging the steam in the gradient adaptive turbine cylinder 3 to the condenser.

[0067] In the above control method, the value range of M% is 0%-100%, and M+N=100.

[0068] For example, when the value of M% is 60%, 70% or 80%, the value of N% is 40%, 30% or 20% respectively.

[0069] Similarly, if the multi-source coordinated steam turbine with full operating efficiency reconstruction adopts Figure 4 For the structural form shown, when the turbine load rate is in the range of M%~100%, the step of disconnecting the clutch between the gradient adaptive turbine rotor and the multi-source cooperative turbine high-pressure cylinder is added; when the turbine load rate is in the range of 0%~M%, the step of engaging the clutch between the gradient adaptive turbine rotor and the multi-source cooperative turbine high-pressure cylinder is added. The remaining steps are the same as the above method and will not be repeated here to save space.

[0070] The steam turbine control method provided by the present invention performs regulation and control based on the operating characteristics of the steam turbine adapted to full-load and high-efficiency operation, and therefore the control method is part of the present invention.

[0071] Different from the existing coal-fired power steam turbines with fixed flow design, the present invention forms an innovative architecture of gradient adaptive turbine and multi-source coordinated steam turbine dual-shaft arrangement by adding gradient adaptive turbine and medium and low pressure combined cylinder. At the same time, combined with the multi-source coordinated steam turbine control method of full operating efficiency reconstruction, the thermal system reconstruction under variable operating conditions is realized, and the key parameters such as main steam pressure, reheat steam pressure and feed water temperature under partial load conditions are significantly improved, which effectively improves the cycle thermal efficiency of the steam turbine under variable operating conditions and ensures that the heat consumption of the steam turbine at 30% rated load does not exceed 10% of the rated load at 100%.

[0072] The above is a detailed introduction to the multi-source coordinated steam turbine and control method for full-condition efficiency reconstruction provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the core idea of the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A multi-source coordinated steam turbine with full-operating efficiency reconstruction, characterized by: include: A multi-source coordinated steam turbine high-pressure cylinder (7), whose steam inlet is connected to the main steam output pipeline of the boiler (1) and is provided with a high-pressure regulating valve (6); the steam exhaust port of the multi-source coordinated steam turbine high-pressure cylinder (7) is connected to the reheat cold section pipeline of the boiler (1); The intermediate pressure cylinder (10) of the multi-source coordinated steam turbine has a steam inlet connected to the reheat steam output pipe of the boiler (1) and is provided with an intermediate pressure cylinder steam inlet regulating valve (8), and a steam exhaust connected to the steam inlet of the low pressure cylinder (14) of the multi-source coordinated steam turbine; A medium- and low-pressure combined cylinder (12) of a multi-source coordinated steam turbine has a steam inlet connected to a reheat steam output pipe of a boiler (1) and is provided with a medium- and low-pressure combined cylinder steam inlet regulating valve (11), and a steam exhaust connected to a condenser; A gradient adaptive turbine comprises a gradient adaptive turbine cylinder (3) and a gradient adaptive turbine rotor (17), wherein the steam inlet of the gradient adaptive turbine cylinder (3) is connected to the main steam output pipe of the boiler (1) and is provided with a gradient adaptive turbine main steam regulating valve (2); the steam exhaust of the gradient adaptive turbine cylinder (3) is divided into two paths, one path is connected to the downstream of the high-pressure regulating valve (6) to lead to the steam inlet of the high-pressure cylinder (7) of the multi-source coordinated steam turbine, and the other path leads to the condenser and is provided with a gradient adaptive turbine ventilation valve (5); The multi-source coordinated steam turbine high-pressure cylinder (7), the multi-source coordinated steam turbine intermediate-pressure cylinder (10), the multi-source coordinated steam turbine intermediate-low pressure combined cylinder (12), and the multi-source coordinated steam turbine low-pressure cylinder (14) are coaxially arranged through the multi-source coordinated steam turbine rotor (15) and connected to the main generator (16); The gradient adaptive turbine is arranged on another axis, and the gradient adaptive turbine rotor (17) is connected to the turbine generator (4); or, the gradient adaptive turbine is arranged coaxially with the multi-source cooperative steam turbine high-pressure cylinder (7), and a clutch is provided between the gradient adaptive turbine rotor (17) and the rotor of the multi-source cooperative steam turbine high-pressure cylinder (7).

2. The multi-source coordinated steam turbine with full-operating efficiency reconstruction according to claim 1 is characterized in that: It also includes a controller (18); the controller (18) is used to control the gradient adaptive turbine main steam regulating valve (2), the high pressure regulating valve (6), the medium pressure cylinder steam inlet regulating valve (8), the medium and low pressure combined cylinder steam inlet regulating valve (11) and the gradient adaptive turbine ventilation valve (5) according to the turbine load rate.

3. The multi-source coordinated steam turbine with full-operating efficiency reconstruction according to claim 1, characterized in that: The multi-source coordinated steam turbine intermediate pressure cylinder (10) is an opposed double intermediate pressure cylinder, comprising a first intermediate pressure cylinder and a second intermediate pressure cylinder that are symmetrically arranged, wherein the first intermediate pressure cylinder and the second intermediate pressure cylinder are provided with parallel intermediate pressure heat recovery extraction pipes (9).

4. The multi-source coordinated steam turbine with full-operating efficiency reconstruction according to claim 1, characterized in that: The multi-source cooperative steam turbine low-pressure combined cylinder (14) is an opposed double low-pressure cylinder, comprising a first low-pressure cylinder and a second low-pressure cylinder arranged symmetrically, wherein the first low-pressure cylinder and the second low-pressure cylinder are provided with parallel low-pressure heat recovery steam extraction pipes (13).

5. The multi-source coordinated steam turbine with full-operating efficiency reconstruction according to claim 1 is characterized in that: The multi-source cooperative steam turbine rotor (15) passes through the multi-source cooperative steam turbine high-pressure cylinder (7), the multi-source cooperative steam turbine intermediate-pressure cylinder (10), the multi-source cooperative steam turbine intermediate- and low-pressure combined cylinder (12), the multi-source cooperative steam turbine low-pressure cylinder (14), and the main generator (16).

6. The multi-source coordinated steam turbine with full-operating efficiency reconstruction according to claim 1, characterized in that: The power output end of the turbine generator (4) is connected to the power grid of the power plant, and the power output end of the main generator (16) is connected to the power grid.

7. The multi-source coordinated steam turbine with full-operating efficiency reconstruction according to claim 1, characterized in that: The flow area of the multi-source cooperative steam turbine intermediate pressure cylinder (10) and the multi-source cooperative steam turbine low pressure cylinder (14) is M% of the total flow area, and the flow area of the multi-source cooperative steam turbine intermediate and low pressure combined cylinder (12) is N% of the total flow area, M+N=100.

8. A control method for a multi-source coordinated steam turbine with full-operating efficiency reconstruction, used to control a multi-source coordinated steam turbine with full-operating efficiency reconstruction according to any one of claims 1 to 7, characterized in that: include: The turbine load rate is obtained in real time. When the turbine load rate is within the range of M% to 100%, the gradient adaptive turbine main steam regulating valve (2) is controlled to be fully closed, the high pressure regulating valve (6) is controlled to be gradually opened to be fully opened as the turbine load percentage increases, the intermediate pressure cylinder steam inlet regulating valve (8) is controlled to be fully opened, the intermediate and low pressure combined cylinder steam inlet regulating valve (11) is controlled to be fully opened, the main steam is operated at sliding pressure, and the main steam pressure is the rated pressure at 100% load; When the turbine load rate is between 0% and M%, the gradient adaptive turbine main steam regulating valve (2) is controlled to be fully opened, the high pressure regulating valve (6) is controlled to be fully closed, the intermediate pressure cylinder steam inlet regulating valve (8) is controlled to be fully opened, and the intermediate and low pressure combined cylinder steam inlet regulating valve (11) is controlled to be fully closed, so that the intermediate and low pressure combined cylinder (12) operates at zero power. At M% load, the main steam pressure and the reheat steam pressure are increased to the pressure values of the rated working condition, thereby realizing that the main and reheat pressures are re-established to the rated values.

9. The multi-source coordinated steam turbine control method for full-operating efficiency reconstruction according to claim 8, characterized in that: When the turbine load rate is higher than M%, the gradient adaptive turbine ventilation valve (5) is also controlled to open, and the steam in the gradient adaptive turbine cylinder (3) is discharged to the condenser.

10. A method for controlling a multi-source coordinated steam turbine with full-operating efficiency reconstruction, the method being used to control a multi-source coordinated steam turbine with full-operating efficiency reconstruction according to any one of claims 1 to 7, characterized in that: include: The steam turbine load rate is obtained in real time. When the steam turbine load rate is in the range of M% to 100%, the clutch between the gradient adaptive turbine rotor (17) and the multi-source coordinated steam turbine high-pressure cylinder (7) is disconnected, the gradient adaptive turbine main steam regulating valve (2) is controlled to be fully closed, the high-pressure regulating valve (6) is controlled to be gradually opened to fully open as the steam turbine load percentage increases, the intermediate-pressure cylinder steam inlet regulating valve (8) is controlled to be fully opened, the intermediate- and low-pressure combined cylinder steam inlet regulating valve (11) is controlled to be fully opened, the main steam is operated at sliding pressure, and the main steam pressure is the rated pressure at 100% load; When the turbine load rate is between 0% and M%, the clutch between the gradient adaptive turbine rotor (17) and the multi-source coordinated turbine high-pressure cylinder (7) is engaged, the gradient adaptive turbine main steam regulating valve (2) is controlled to be fully opened, the high-pressure regulating valve (6) is controlled to be fully closed, the intermediate-pressure cylinder steam inlet regulating valve (8) is controlled to be fully opened, and the intermediate- and low-pressure combined cylinder steam inlet regulating valve (11) is controlled to be fully closed, so that the intermediate- and low-pressure combined cylinder (12) operates at zero power. At M% load, the main steam pressure and the reheat steam pressure are increased to the pressure values of the rated operating conditions, thereby realizing that the main and reheat pressures are re-established to the rated values.

11. The multi-source coordinated steam turbine control method for full-operating efficiency reconstruction according to claim 10, characterized in that: When the turbine load rate is higher than M%, the gradient adaptive turbine ventilation valve (5) is also controlled to open, and the steam in the gradient adaptive turbine cylinder (3) is discharged to the condenser.

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