A steam turbine-based combined extraction and injection generator set

Abstract

The application discloses a steam turbine-based leading and increasing combined generator unit and relates to the technical field of thermal power generation. The unit comprises a steam turbine, a variable-speed clutch structure, an asynchronous motor and a leading fan which are coaxially arranged in sequence. The steam turbine and the asynchronous motor are connected through the variable-speed clutch structure. The variable-speed clutch structure is composed of a speed reducer and a clutch box. The technical advantage of the application is that: the combination of the asynchronous motor and the steam turbine realizes steam-electric dual drive. The steam drive and the electric drive are used as backup for each other. The steam drive and the electric drive can be used simultaneously, and the reliability is high. The application efficiently promotes the energy saving and consumption reduction of the leading fan in the coal-fired generator unit. When the asynchronous motor is applied as an electric motor in the starting stage, the starting conditions of the fan can be simplified, and the auxiliary power consumption rate of the coal-fired generator unit is greatly reduced. When the asynchronous motor is applied as a generator, the corresponding output power is increased. The power is integrated into the auxiliary power grid, thereby reducing the auxiliary power consumption rate and improving the overall power generation efficiency of the unit.

Description

Technical Field

[0001] This application relates to the field of thermal power generation technology, and in particular to a combined induced draft and induced draft generator set based on a steam turbine. Background Technology

[0002] By the end of 2024, my country's installed power generation capacity reached a historic milestone of 3.35 billion kilowatts, continuing to lead the world in scale and setting an industry benchmark in technological innovation and green transformation. For the first time, the installed capacity of wind, solar, and new energy power generation surpassed that of traditional thermal power, marking a profound transformation in my country's energy structure. However, the volatility and intermittent nature of wind and solar power mean that large-scale grid connection still faces both technological and institutional challenges. During periods of insufficient sunshine and weak winds, the balance between power supply and demand is easily disrupted. Thermal power units, with their rapid response capabilities and stable output characteristics, remain the "stabilizer" and "ballast" for ensuring the safe and stable operation of the power grid. Coal-fired power units, through flexible retrofitting, can achieve significant power adjustments within minutes. The synergistic complementarity between gas turbine units and new energy sources has built a new power structure that both ensures energy security and promotes green transformation, providing solid support for the sustainable development of my country's energy system.

[0003] The induced draft fan draws flue gas from the boiler to maintain a stable negative pressure environment (usually -20 to -50 Pa) in the furnace. This prevents high-temperature flue gas from leaking out, ensuring the safety of personnel and equipment, and also prevents cold air from entering the furnace and affecting combustion efficiency. The induced draft fan power of a 1000MW coal-fired power unit used in gas turbine units is generally 7000KW, and the booster fan power is generally 3000KW, totaling 10MW of power. This results in huge energy consumption. The main reason why the plant's power consumption rate remains high even after steam-driven feedwater pumps are widely adopted is that the plant's power consumption rate remains high. How to fully explore, utilize, and integrate existing technologies to improve power generation efficiency and reduce unit energy consumption and power generation costs is one of the main research and development directions for coal-fired power generator units. Utility Model Content

[0004] This device provides a turbine-based integrated induced draft fan and booster fan generator set, which eliminates the traditional design of separate electric induced draft fans and booster fans. It adopts a design that combines a large-capacity induced draft fan and booster fan, and uses a back-pressure small steam turbine and an electric motor to jointly drive the induced draft fan. The specific implementation method is as follows: A combined induced draft and induced draft generator set based on a steam turbine, comprising: The steam turbine, the variable speed clutch structure, the asynchronous motor and the induced draft fan are arranged coaxially in sequence, and the steam turbine and the asynchronous motor are connected by the variable speed clutch structure. The variable speed clutch structure consists of a reduction gearbox and a clutch box. During the starting phase, the variable speed clutch structure is in neutral, and the asynchronous motor is used as a motor. After starting, the variable speed clutch structure is engaged, and the asynchronous motor is used as a generator for energy storage.

[0005] Based on the above technical solutions, the addition of an asynchronous motor reduces the plant's power consumption rate and improves power supply efficiency. After merging the induced draft fan and the booster fan, a scheme is adopted where a small steam turbine and an electric motor jointly drive the induced draft fan. This involves a small steam turbine, a variable-speed clutch structure, a three-phase asynchronous motor / generator, and the induced draft fan connected in series on a shaft system. The small steam turbine is selected based on the shaft power at the TB point of the induced draft fan and operates at a constant speed. When the induced draft fan is operating at or below the higher load at the TB point, the small steam turbine drives both the induced draft fan and the electric motor at full load, with the electric motor acting as a generator to provide power. Plant power; when the unit is running at low load, if the sum of the generator output and the induced draft fan power is less than the turbine output, or if the plant power load cannot absorb the generator output, the small turbine can be operated at a reduced load to balance the power of the combined drive system; when the unit starts, the generator is started by the generator motor, and the small turbine is disengaged from the combined steam-electric drive system by the clutch; the induced draft fan is designed for constant speed, and the high-speed constant-speed small turbine is matched with the speed of the generator motor and the induced draft fan after being decelerated by the variable speed clutch. The speed ratio of the variable speed clutch structure is determined according to the speed of the small turbine and the induced draft fan.

[0006] Preferably, the clutch housing is provided with a first gear, a second gear, and a third gear that mesh sequentially. The first gear is connected to the steam turbine via an input shaft, the second gear is connected to the input end of the gearbox, and the third gear is coaxially connected to a speed sensor.

[0007] Preferably, the gearbox is composed of several reduction gears, and the output end of the gearbox is connected to the asynchronous motor through an output shaft.

[0008] Preferably, the gearbox and the clutch box are connected as one unit through a base plate, and a clutch part is provided between the gearbox and the second gear, and a control push rod is slidably provided after the clutch part passes through the clutch box.

[0009] Based on the above technical solution, the speed sensor is externally mounted, and the push rod can be manually adjusted to switch whether the gearbox and clutch are in a linked state.

[0010] Preferably, the clutch includes a first drive shaft sleeved inside the second gear, and a first fixed gear ring fixedly mounted on the first drive shaft at a position other than the second gear; a sleeve and a synchronizing gear ring are also slidably mounted on the first drive shaft, and the inner side of the sleeve is splinedly fitted to the first fixed gear ring and the synchronizing gear ring.

[0011] Preferably, the sleeve is composed of a fixed part and a rotating part, and the second gear is coaxially provided with a second fixed gear ring. Both the synchronous gear ring and the second fixed gear ring are provided with friction cone surfaces along the circumferential direction for the rotating part in the sleeve to be axially inserted.

[0012] Preferably, the fixed part in the sleeve extends out of the clutch box and is connected to an active telescopic structure.

[0013] Based on the above technical solutions, the active telescopic structure is preferably a cylinder, but it can also be an electric telescopic cylinder or a hydraulic cylinder, etc.; the fixed part of the sleeve is connected to the telescopic end of the cylinder through a push rod, and the length of the rotating part in the sleeve is greater than the total length of the second fixed gear ring, the synchronous gear ring and the first fixed gear ring. When the gearbox and the clutch are linked, the inner side of the rotating part is splined to all three, and the friction cone surface is used to improve the axial connection effect between the fixed gear ring and the synchronous gear ring.

[0014] Preferably, the inner end face of the clutch box is provided with a partition, and the first gear and the third gear are rotatably connected to the partition through the second transmission shaft, and a bearing is provided at the rotation point.

[0015] Preferably, the end face of the partition plate is provided with an inner groove, and the bearing is embedded in the inner groove.

[0016] In summary, this application includes the following beneficial technical effects: 1. This utility model achieves dual steam and electric drive by combining an asynchronous motor with a steam turbine. The steam and electric drives serve as backups for each other and can also be used simultaneously, resulting in high reliability. 2. This utility model efficiently promotes energy saving and consumption reduction in the operation of induced draft fans in coal-fired power units. When the asynchronous motor is used as a motor during the start-up phase, it can simplify the start-up conditions of the fan and significantly reduce the power consumption rate of the coal-fired power unit. When the asynchronous motor is used as a generator, the corresponding output power increases. After this part of the power is connected to the power grid, the power consumption rate is reduced and the overall power generation efficiency of the unit is improved. 3. This utility model has a simple structure. By setting a first gear, a second gear, and a third gear inside the clutch box, it achieves compatible installation of the clutch part and the speed sensor. Through the active movement of the sleeve and with the help of the first fixed gear ring, the second fixed gear ring, and the synchronous gear ring, it achieves stable engagement and disengagement between the reduction gearbox and the clutch box, further improving the overall power generation efficiency of the unit. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the variable speed clutch structure in this utility model. Figure 1 ; Figure 3 This is a schematic diagram of the variable speed clutch structure in this utility model. Figure 1 two; Figure 4 This is an exploded schematic diagram of the variable speed clutch structure in this utility model; Figure 5 This is a cross-sectional schematic diagram of the variable speed clutch structure in this utility model; Figure 6 This is a cross-sectional schematic diagram of the clutch box structure in this utility model.

[0018] Explanation of reference numerals in the attached figures: 1. Asynchronous motor; 2. Exhaust fan; 3. Steam turbine; 4. Gearbox; 5. Clutch box; 6. Active telescopic structure; 7. Input shaft; 8. Output shaft; 9. Sleeve; 10. Speed ​​sensor; 11. Base plate; 12. Bearing. 501, First gear; 502, Second gear; 503, Third gear; 504, Second fixed gear ring; 505, First fixed gear ring; 506, Synchronizing gear ring; 507, First drive shaft; 508, Second drive shaft; 509, Partition plate; 5091, Inner groove. Detailed Implementation

[0019] The specific embodiments of this utility model are described below with reference to the accompanying drawings and examples: It should be noted that the structures, proportions, sizes, etc. shown in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which the present invention can be implemented. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and purposes that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0020] Meanwhile, the terms such as "upper", "lower", "left", "right", "middle" and "one" used in this specification are only for clarity of description and are not intended to limit the scope of implementation of this utility model. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered as within the scope of implementation of this utility model.

[0021] The following is in conjunction with the appendix Figure 1-6 This application will be described in further detail.

[0022] This application discloses a combined induced draft and induced draft generator set based on a steam turbine.

[0023] Example 1 Reference Figure 1 This embodiment discloses a combined induced draft and induced draft generator set based on a steam turbine, including a steam turbine 3, a variable speed clutch structure, an asynchronous motor 1, and an induced draft fan 2 arranged coaxially in sequence. The steam turbine 3 and the asynchronous motor 1 are connected by the variable speed clutch structure. In this structure, the variable speed clutch structure consists of a reduction gearbox 4 and a clutch box 5. During the start-up phase, the variable speed clutch structure is in neutral, and the asynchronous motor 1 is used as a motor. After start-up, the variable speed clutch structure is connected, and the asynchronous motor 1 is used as a generator for energy storage.

[0024] The specific implementation process is as follows: When the unit starts, the asynchronous motor 1 starts as a motor, and the turbine 3 is disengaged from the drive system by the speed change clutch structure. The asynchronous motor 1 directly drives the induced draft fan 2 to rotate. After normal operation, the speed change clutch structure connects the turbine 3 to the drive system, and the asynchronous motor 1 is used as a generator. During the process of the turbine 3 driving the induced draft fan 2 to rotate, it also drives the asynchronous motor 1 to generate electricity.

[0025] Example 2 Reference Figures 1 to 6 In addition to the above embodiments, this embodiment also discloses a turbine-based integrated generator set for both starting and stopping. The gearbox 4 and clutch 5 are connected as a whole by a base plate 11. The clutch 5 is provided with a first gear 501, a second gear 502 and a third gear 503 that mesh sequentially. The first gear 501 is connected to the turbine 3 through an input shaft 7. The second gear 502 is connected to the input end of the gearbox 4. The third gear 503 is coaxially connected to a speed sensor 10. In this structure, the inner end face of the clutch 5 is provided with a partition 509. The first gear 501 and the third gear 503 are rotatably connected to the partition 509 through a second transmission shaft 508. A bearing 12 is provided at the rotatable part. The end face of the partition 509 is provided with an inner groove 5091. The bearing 12 is embedded in the inner groove 5091.

[0026] The reduction gearbox 4 is composed of several reduction gears, and the output end of the reduction gearbox 4 is connected to the asynchronous motor 1 through the output shaft 8. In this structure, a clutch part is provided between the reduction gearbox 4 and the second gear 502, and a control push rod is slidably provided after the clutch part passes through the clutch box 5.

[0027] Example 3 Reference Figures 1 to 6 In addition to the above embodiments, this embodiment also discloses a combined generator set based on a steam turbine, wherein the clutch includes a first drive shaft 507 sleeved inside the second gear 502, and a second fixed gear ring 504 fixedly mounted on the first drive shaft 507 at a position other than the second gear 502. A sleeve 9 and a synchronizing gear ring 506 are also slidably mounted on the first drive shaft 507, and the inner spline of the sleeve 9 is engaged with the second fixed gear ring 504 and the synchronizing gear ring 506.

[0028] The sleeve 9 consists of a fixed part and a rotating part. The second gear 502 is coaxially provided with a first fixed gear ring 505. Both the synchronizing gear ring 506 and the first fixed gear ring 505 are provided with friction cone surfaces along the circumferential direction for the rotating part in the sleeve 9 to be axially inserted. The fixed part in the sleeve 9 passes through the clutch box 5 and is connected to an active telescopic structure 6. The active telescopic structure 6 is a cylinder. The synchronizing gear ring 506 and the first fixed gear ring 505 are provided with friction cone surfaces at equal intervals along the circumferential direction, and the cone directions of the two are opposite. The synchronizing gear ring 506 improves the stability of the sleeve 9 in axially locking the first fixed gear ring 505 and the second fixed gear ring 504.

[0029] The specific implementation process is as follows: During the linkage operation, the steam turbine 3 inputs power sequentially to the first gear 501, the second gear 502, the first fixed gear ring 505, the rotating part of the sleeve 9, and the second fixed gear ring 504 through the input shaft 7, and finally transmits it to the asynchronous motor 1 and the induced draft fan 2 through the output shaft 8; when the clutch is opened, the active telescopic structure 6 drives the sleeve 9 to move axially, the rotating part of the sleeve 9 disengages from the second fixed gear ring 504, and the asynchronous motor 1 directly drives the induced draft fan 2 as a motor.

[0030] Many other changes and modifications can be made without departing from the concept and scope of this utility model. It should be understood that this utility model is not limited to the specific embodiments, and the scope of this utility model is defined by the appended claims.

Claims

1. A combined induced draft and induced draft generator set based on a steam turbine, characterized in that, include: A steam turbine (3), a speed-changing clutch structure, an asynchronous motor (1) and an induced draft fan (2) are arranged coaxially in sequence. The steam turbine (3) and the asynchronous motor (1) are connected by the speed-changing clutch structure. The speed-changing clutch structure consists of a reduction gearbox (4) and a clutch box (5). During the starting phase, the speed-changing clutch structure is in neutral, and the asynchronous motor (1) is used as a motor. After starting, the speed-changing clutch structure is connected, and the asynchronous motor (1) is used as a generator for energy storage.

2. The integrated generator set based on a steam turbine, as described in claim 1, is characterized in that, The clutch box (5) is provided with a first gear (501), a second gear (502) and a third gear (503) that mesh in sequence. The first gear (501) is connected to the steam turbine (3) through the input shaft (7), the second gear (502) is connected to the input end of the gearbox (4), and the third gear (503) is coaxially connected to a speed sensor (10).

3. The integrated generator set based on a steam turbine, as described in claim 2, is characterized in that... The gearbox (4) is composed of several reduction gears, and the output end of the gearbox (4) is connected to the asynchronous motor (1) through the output shaft (8).

4. A combined turbine-based generator set for both induction and boosting, as described in claim 3, is characterized in that... The gearbox (4) and the clutch box (5) are connected as one unit through the base plate (11). The gearbox (4) and the second gear (502) are provided with a clutch part, and the clutch part is slidably provided with a control push rod after passing through the clutch box (5).

5. A combined turbine-based generator set according to claim 4, characterized in that, The clutch includes a first drive shaft (507) sleeved inside the second gear (502), and a second fixed gear ring (504) is fixedly provided on the first drive shaft (507) at a position other than the second gear (502). A sleeve (9) and a synchronous gear ring (506) are also slidably provided on the first drive shaft (507), and the inner spline of the sleeve (9) is engaged with the second fixed gear ring (504) and the synchronous gear ring (506).

6. A combined turbine-based generator set for both induction and boosting, as described in claim 5, is characterized in that... The sleeve (9) is composed of a fixed part and a rotating part. The second gear (502) is coaxially provided with a first fixed gear ring (505). The synchronous gear ring (506) and the first fixed gear ring (505) are both provided with friction cone surfaces along the circumferential direction for the rotating part in the sleeve (9) to be axially inserted.

7. A combined turbine-based generator set according to claim 6, characterized in that, The fixed part of the sleeve (9) extends out of the clutch box (5) and is connected to the active telescopic structure (6).

8. A combined turbine-based generator set for both induction and boosting, as described in claim 7, is characterized in that... The clutch box (5) has a partition (509) on its inner end face. The first gear (501) and the third gear (503) are rotatably connected to the partition (509) through the second transmission shaft (508), and a bearing (12) is provided at the rotation point.

9. A combined steam turbine generator set according to claim 8, characterized in that, The end face of the partition (509) is provided with an inner groove (5091), and the bearing (12) is embedded in the inner groove (5091).

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