A steam turbine regenerative system

Abstract

The application discloses a steam turbine regenerative system, and relates to the technical field of steam turbines, which comprises a boiler, a steam turbine and a steam turbine condenser, wherein the steam turbine comprises a high-pressure cylinder, a medium-pressure cylinder and a low-pressure cylinder; the boiler is communicated with the high-pressure cylinder through a main steam pipeline; the high-pressure cylinder, the medium-pressure cylinder, the low-pressure cylinder and the steam turbine condenser are sequentially communicated through pipelines; the steam turbine regenerative system further comprises a third pressure boosting component and a regenerative component; the third pressure boosting component comprises a No. 3 high-pressure heater steam augmentor, a shunt pipeline and a seventh steam extraction pipeline; and the regenerative component comprises a No. 3 high-pressure heater. The power steam inlet of the No. 3 high-pressure heater steam augmentor is communicated with the main steam pipeline through the shunt pipeline; and the suction port of the No. 3 high-pressure heater steam augmentor is communicated with the first-stage steam extraction port of the high-pressure cylinder through the seventh steam extraction pipeline. The application can improve the unstable operation of the boiler in the peak regulation state.

Description

Technical Field

[0001] This application relates to the technical field of steam turbines, and in particular to a steam turbine regenerative system. Background Technology

[0002] Electricity consumption in urban and rural areas often fluctuates between peak and off-peak periods, resulting in an imbalance between demand and load. During peak hours, the power grid often operates beyond its normal capacity. This necessitates the activation of peak-shaving power plants and the commissioning of generator units not in regular operation to meet demand. Correspondingly, thermal power units, due to their primary energy source, adjustability, and controllability, are utilized for "deep peak shaving" to meet power generation needs. However, this deep peak shaving inevitably impacts turbine equipment, potentially leading to turbine shutdowns and drastically reduced equipment lifespan in severe cases, thus requiring careful attention.

[0003] Deep peak shaving is achieved by altering the load of thermal power units, based on their power generation demand. When demand is high, the units operate at high load; when demand is low, they operate at low load. Since the boiler furnace structure and the design of each heating surface are based on the overall thermal balance of the thermal power unit, after deducting corresponding heat losses, all the heat entering the boiler becomes steam. If a significant change occurs in any part of the heat, it will cause a significant change in the parameters of that portion of the steam, thus affecting the safe operation of the boiler.

[0004] During deep peak shaving, the extraction parameters of each stage of the steam turbine decrease, which has a significant impact on the normal operation of the boiler. This is mainly reflected in the fact that when power demand decreases and the thermal power unit operates at low load, the steam intake of the high-pressure cylinder decreases. Since the amount of steam produced by the boiler remains constant during this period, the decrease in the extraction parameters of the high-pressure cylinder causes the exhaust steam pressure to deviate from the boiler's allowable value. This results in insufficient steam at the boiler reheater inlet, a decrease in the boiler feedwater temperature, and affects the stable operation of the denitrification system. Consequently, the boiler may fail to achieve stable combustion, making it prone to problems such as flameout and backfiring. Summary of the Invention

[0005] In order to improve the unstable operation of boilers under peak-shaving conditions, this application provides a steam turbine regenerative system.

[0006] This application provides a steam turbine regenerative system, which adopts the following technical solution:

[0007] A steam turbine regenerative system includes a boiler, a steam turbine, a main steam pipeline, and a steam turbine condenser. The steam turbine includes a high-pressure cylinder, an intermediate-pressure cylinder, and a low-pressure cylinder. The boiler is connected to the high-pressure cylinder through the main steam pipeline. The high-pressure cylinder, the intermediate-pressure cylinder, the low-pressure cylinder, and the steam turbine condenser are connected sequentially through an exhaust pipe.

[0008] The turbine regenerative system also includes a third pressurization assembly and a regenerative assembly. The third pressurization assembly includes a No. 3 high-pressure heater booster turbine, a diversion pipe, and a seventh extraction pipe. The regenerative assembly includes a No. 3 high-pressure heater. The power steam inlet of the No. 3 high-pressure heater booster turbine is connected to the main steam pipe through the diversion pipe. The suction port of the No. 3 high-pressure heater booster turbine is connected to the first-stage extraction port of the high-pressure cylinder through the seventh extraction pipe. The steam inlet of the No. 3 high-pressure heater is connected to the exhaust port of the No. 3 high-pressure heater booster turbine. The water inlet of the No. 3 high-pressure heater is connected to the drain port of the turbine condenser. The drain port of the No. 3 high-pressure heater is connected to the boiler water inlet.

[0009] By adopting the above technical solution, during operation of the thermal power unit, the boiler feedwater is heated to the main steam parameters in the boiler superheater and then enters the high-pressure cylinder of the turbine to perform work. The exhaust steam from the high-pressure cylinder enters the boiler reheater to absorb heat and upgrade its properties before entering the intermediate-pressure cylinder of the turbine to perform work. The exhaust steam from the intermediate-pressure cylinder enters the low-pressure cylinder of the turbine to perform work before entering the turbine condenser. The steam is cooled and condensed into condensate in the turbine condenser and enters the regenerative assembly. After passing through the No. 3 high-pressure heater, it finally returns to the boiler for heating.

[0010] During deep peak shaving, because the turbine is operating at low load, the extraction and exhaust parameters of the high-pressure cylinder are correspondingly reduced. A portion of the main steam is diverted through a split pipe as motive steam, which is then used to extract steam from the first stage of the high-pressure cylinder. This extracted steam enters the No. 3 high-pressure heater booster turbine and mixes with the main steam to increase its pressure. Finally, the exhaust steam enters the No. 3 high-pressure heater. Regarding the extraction parameters of each stage of the high-pressure cylinder, since the pressure of the first stage extraction is approximately 1.6-1.7 times the high-pressure cylinder exhaust pressure, when the No. 3 high-pressure heater booster turbine uses the main steam to extract steam from the first stage, the pressure and temperature parameters of the steam at the No. 3 high-pressure heater booster turbine can be restored to the actual working fluid parameters required by the reheater under this operating condition. This ensures the safe operation of the reheater, significantly increases the boiler feedwater temperature, and solves the problem of unstable operation of the denitrification system under low load flue gas temperature.

[0011] Optionally, the third pressurization assembly further includes a third high-pressure steam regulating valve, a third low-pressure steam regulating valve, and a first-stage extraction steam regulating valve. The third high-pressure steam regulating valve is installed on the diversion pipe, and the third low-pressure steam regulating valve is installed on the seventh extraction steam pipe.

[0012] The seventh extraction steam pipe is also directly connected to the steam inlet of the third high-pressure heater through the third regulating pipe, and the first extraction steam regulating valve is installed on the third regulating pipe.

[0013] By adopting the above technical solution, when the thermal power unit is not in a deep-adjustment state, the third high-pressure steam regulating valve can be used to isolate the main steam pipeline and the branch pipeline, and the third low-pressure steam regulating valve can be used to isolate the first stage extraction port of the high-pressure cylinder and the No. 3 high-pressure heater booster turbine. Closing the third high-pressure steam regulating valve and the third low-pressure steam regulating valve, and opening the first stage extraction steam regulating valve, allows the No. 3 high-pressure heater booster turbine to stop operating, without changing the original operating mode of the unit's regenerative system.

[0014] Optionally, the turbine regenerative system further includes a second pressurization assembly, which includes a deaerator booster and a fourth extraction steam pipe. The regenerative assembly also includes a deaerator, which is disposed between the turbine condenser and the No. 3 high-pressure heater.

[0015] The deaerator booster steam inlet is connected to the second stage extraction port of the high-pressure cylinder, the deaerator booster suction port is connected to the fourth stage extraction port of the intermediate-pressure cylinder through the fourth extraction pipe, and the deaerator steam inlet is connected to the deaerator booster exhaust port.

[0016] By adopting the above technical solution, the second-stage extraction steam from the high-pressure cylinder is used as the driving steam to induce the fourth-stage extraction steam from the intermediate-pressure cylinder. This fourth-stage extraction steam enters the deaerator's booster turbine and mixes with the second-stage extraction steam to increase its pressure. Finally, the pressurized exhaust steam enters the deaerator, thus alleviating the problem of insufficient deaerator output due to low inlet steam parameters during deep peak shaving. Compared to the main steam, the pressure of the second-stage extraction steam from the high-pressure cylinder is more compatible with the deaerator's inlet steam design pressure. This improves the situation where using main steam to induce exhaust steam from the high-pressure cylinder into the deaerator causes the deaerator's inlet steam to exceed its design pressure, potentially leading to safety accidents.

[0017] Optionally, the second pressurization assembly further includes a second high-pressure steam regulating valve, a second low-pressure steam regulating valve, and a four-stage extraction steam regulating valve. The second high-pressure steam regulating valve is located between the second-stage extraction steam port of the high-pressure cylinder and the power steam inlet of the deaerator booster, and the first low-pressure steam regulating valve is located on the fourth extraction steam pipe.

[0018] The fourth extraction steam pipe is also directly connected to the deaerator inlet via the second regulating pipe, and the four-stage extraction steam regulating valve is installed on the second regulating pipe.

[0019] By adopting the above technical solution, when the thermal power unit is not in a deep adjustment state, the second high-pressure steam regulating valve can be used to isolate the deaerator boiler and the second stage extraction port of the high-pressure cylinder, and the second low-pressure steam regulating valve can be used to isolate the fourth stage extraction port of the intermediate-pressure cylinder and the deaerator boiler. Closing the second high-pressure steam regulating valve and the second low-pressure steam regulating valve, and opening the fourth stage extraction steam regulating valve, allows the deaerator boiler to be taken out of operation without changing the original operating mode of the unit's regenerative system.

[0020] Optionally, the turbine regenerative system further includes a first pressure boosting assembly, which includes a first low-pressure heater, a steam booster, and a first extraction steam pipe. The regenerative assembly also includes a first low-pressure heater, which is disposed between the turbine condenser and the third high-pressure heater.

[0021] The power steam inlet of the first low-pressure heater booster is connected to the fourth section of the extraction port of the intermediate-pressure cylinder. The suction port of the first low-pressure heater booster is connected to the seventh section of the extraction port of the low-pressure cylinder through the first extraction pipe. The steam inlet of the first low-pressure heater is connected to the exhaust port of the first low-pressure heater booster.

[0022] By adopting the above technical solution, the fourth-stage extraction steam port of the intermediate-pressure cylinder is used as the driving steam to induce the seventh-stage extraction steam of the low-pressure cylinder. The seventh-stage extraction steam enters the first low-pressure heater's booster turbine and mixes with the fourth-stage extraction steam to increase its pressure. Finally, the pressurized exhaust steam enters the No. 1 low-pressure heater. This allows for the increase of the seventh-stage extraction steam parameters during deep peak shaving, thereby increasing the outlet water temperature of the No. 1 low-pressure heater during deep peak shaving and alleviating the problem of insufficient output of the No. 1 low-pressure heater during deep peak shaving.

[0023] Optionally, the first booster assembly further includes a first high-pressure steam regulating valve, a first low-pressure steam regulating valve, and a seven-stage extraction steam regulating valve. The first high-pressure steam regulating valve is located between the four-stage extraction steam port of the intermediate-pressure cylinder and the power steam inlet of the first low-pressure heater booster. The first low-pressure steam regulating valve is located on the first extraction steam pipeline, and the first extraction steam pipeline is equipped with a four-stage extraction steam regulating valve.

[0024] The first extraction steam pipe is also directly connected to the steam inlet of the No. 1 low-pressure heater through the first regulating pipe, and the seven-stage extraction steam regulating valve is installed on the first regulating pipe.

[0025] By adopting the above technical solution, when the thermal power unit is not in a deep adjustment state, the first high-pressure steam regulating valve can be used to isolate the first low-pressure heater turbine and the fourth stage extraction port of the intermediate-pressure cylinder, and the first low-pressure steam regulating valve can be used to isolate the seventh stage extraction port of the low-pressure cylinder and the first low-pressure heater turbine. Closing the first high-pressure steam regulating valve and the first low-pressure steam regulating valve, and opening the seventh stage extraction regulating valve, allows the first low-pressure heater turbine to stop operating without changing the original operation mode of the unit's regenerative system.

[0026] Optionally, the regenerative assembly further includes a second low-pressure heater and a second extraction steam pipe. The second low-pressure heater is located between the first low-pressure heater and the third high-pressure heater. One end of the second extraction steam pipe is connected to the sixth extraction steam port of the low-pressure cylinder, and the other end is connected to the steam inlet of the second low-pressure heater. A six-stage extraction steam regulating valve is provided on the second extraction steam pipe.

[0027] By adopting the above technical solution, the No. 2 low-pressure heater draws steam from the sixth stage of the low-pressure cylinder through the second extraction steam pipe, and heats the condensate produced by the turbine condenser through the No. 2 low-pressure heater. Together with the No. 1 low-pressure heater and the No. 3 high-pressure heater, it achieves staged heating, causing the boiler feedwater temperature to gradually rise. When the No. 2 low-pressure heater malfunctions, the steam is isolated through the sixth-stage extraction steam regulating valve.

[0028] Optionally, the regenerative assembly further includes a third low-pressure heater and a third extraction steam pipe. The third low-pressure heater is located between the second low-pressure heater and the third high-pressure heater. One end of the third extraction steam pipe is connected to the fifth extraction steam port of the low-pressure cylinder, and the other end is connected to the steam inlet of the third low-pressure heater. A five-stage extraction steam regulating valve is provided on the third extraction steam pipe.

[0029] By adopting the above technical solution, the No. 3 low-pressure heater draws steam from the fifth stage of the low-pressure cylinder through the third extraction steam pipe, and further heats the condensate produced by the turbine condenser through the No. 3 low-pressure heater, thereby gradually increasing the boiler feedwater temperature. When the No. 3 low-pressure heater malfunctions, the steam is isolated through the fifth stage extraction steam regulating valve.

[0030] Optionally, the regenerative assembly further includes a first high-pressure heater and a fifth extraction steam pipe. The first high-pressure heater is located between the third high-pressure heater and the third low-pressure heater. One end of the fifth extraction steam pipe is connected to the third-stage extraction steam port of the intermediate-pressure cylinder, and the other end is connected to the steam inlet of the first high-pressure heater. A three-stage extraction steam regulating valve is provided on the fifth extraction steam pipe.

[0031] By adopting the above technical solution, the No. 1 high-pressure heater draws steam from the second stage of the high-pressure cylinder through the fifth extraction steam pipe, and further heats the condensate produced by the turbine condenser through the No. 2 high-pressure heater, thereby gradually increasing the boiler feedwater temperature. When the No. 1 high-pressure heater malfunctions, the steam is isolated through the third-stage extraction steam regulating valve.

[0032] Optionally, the regenerative assembly further includes a second high-pressure heater and a sixth extraction steam pipe. The second high-pressure heater is located between the first high-pressure heater and the third high-pressure heater. One end of the sixth extraction steam pipe is connected to the second-stage extraction steam port of the high-pressure cylinder, and the other end is connected to the steam inlet of the second high-pressure heater. A second-stage extraction steam regulating valve is provided on the sixth extraction steam pipe.

[0033] By adopting the above technical solution, the No. 2 high-pressure heater draws steam from the second stage of the high-pressure cylinder through the sixth extraction steam pipe, and further heats the condensate produced by the turbine condenser through the No. 2 high-pressure heater, thereby gradually increasing the boiler feedwater temperature. When the No. 2 high-pressure heater malfunctions, the steam is isolated through the second-stage extraction steam regulating valve.

[0034] In summary, this application includes at least one of the following beneficial effects:

[0035] 1. By setting up a No. 3 high-pressure heater steam booster, the main steam is used to extract a section of steam, and the exhaust steam enters the No. 3 high-pressure heater. During the deep peak shaving of the unit, the extraction steam parameters are increased, thereby increasing the output of the No. 3 high-pressure heater and ultimately increasing the feedwater temperature, thus solving the problem of the denitrification system being unable to operate stably under low load conditions.

[0036] 2. By setting up a deaerator steam booster, the high-pressure cylinder second-stage extraction steam is used to eject the intermediate-pressure cylinder exhaust steam, which enters the deaerator. During the deep peak shaving of the unit, the fourth-stage extraction steam parameter is increased, thereby improving the problem of insufficient deaerator output during the deep peak shaving of the unit.

[0037] 3. By setting up a No. 1 low-pressure heater steam booster, the exhaust steam from the intermediate-pressure cylinder is used to inject the low-pressure seven-stage extraction steam. The exhaust steam enters the No. 1 low-pressure heater, increasing the extraction steam parameters of the seven stages during deep peak shaving of the unit. This increases the outlet water temperature of the No. 1 low-pressure heater during deep peak shaving of the unit, alleviating the problem of insufficient output of the unit's low-pressure heater during deep peak shaving.

[0038] 4. By setting corresponding regulating valves, when the unit is not under deep adjustment, the No. 3 high-pressure heater booster turbine, the deaerator booster turbine, and the No. 1 low-pressure heater booster turbine can be shut down through valve isolation without changing the original operation mode of the unit's regenerative system. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the overall structure of the turbine regenerative system in an embodiment of this application.

[0040] Figure 2 This is a partial structural schematic diagram of the steam turbine in an embodiment of this application.

[0041] Explanation of reference numerals in the attached diagram: 1. Boiler; 11. Superheater; 111. Main steam pipe; 12. Reheater; 2. Steam turbine; 21. High-pressure cylinder; 211. First-stage extraction port; 212. Second-stage extraction port; 22. Intermediate-pressure cylinder; 221. Third-stage extraction port; 222. Fourth-stage extraction port; 223. Control valve; 23. Low-pressure cylinder; 231. Fifth-stage extraction port; 232. Sixth-stage extraction port; 233. Seventh-stage extraction port; 3. Generator; 4. Steam turbine condenser; 5. Regenerative assembly; 51. Condensate pump; 52. No. 1 low-pressure heater; 53. No. 2 low-pressure heater; 531. Second extraction steam pipeline; 532. Sixth-stage extraction steam regulating valve; 54. No. 3 low-pressure heater; 541. Third extraction steam pipeline; 542. Fifth-stage extraction steam regulating valve; 55. Deaerator; 56. Feedwater pump; 57. No. 1 high-pressure heater; 571. Fifth extraction steam pipeline; 572. Third-stage extraction steam regulating valve; 58. No. 2 high-pressure heater; 581. Sixth extraction steam pipeline; 582. Second-stage extraction steam regulating valve; 59. No. 3 high-pressure heater;

[0042] 6. First pressure boosting assembly; 61. First low-pressure heater booster; 62. First extraction steam pipeline; 63. First high-pressure steam regulating valve; 64. First low-pressure steam regulating valve; 65. First regulating pipeline; 66. Seven-stage extraction steam regulating valve; 7. Second pressure boosting assembly; 71. Deaerator booster; 72. Fourth extraction steam pipeline; 73. Second high-pressure steam regulating valve; 74. Second low-pressure steam regulating valve; 75. Second regulating pipeline; 76. Four-stage extraction steam regulating valve; 8. Third pressure boosting assembly; 81. No. 3 high-pressure heater booster; 82. Diversion pipeline; 83. Seventh extraction steam pipeline; 84. Third high-pressure steam regulating valve; 85. Third low-pressure steam regulating valve; 86. Third regulating pipeline; 87. First-stage extraction steam regulating valve. Detailed Implementation

[0043] The following is in conjunction with the appendix Figure 1 - Appendix Figure 2 This application will be described in further detail.

[0044] Reference Figure 1 This application discloses a steam turbine regenerative system, including a boiler 1, a steam turbine 2, a steam turbine condenser 4, a regenerative assembly 5, and a generator 3. The steam turbine 2 includes a high-pressure cylinder 21, an intermediate-pressure cylinder 22, and a low-pressure cylinder 23. The boiler 1 is connected to the high-pressure cylinder 21 via a main steam pipe 111. The generator 3 is located on one side of the steam turbine 2. The intermediate-pressure cylinder 22, the low-pressure cylinder 23, and the steam turbine condenser 4 are sequentially connected via pipes. The steam turbine condenser 4 is connected to the boiler 1 via the regenerative assembly 5. A first pressure-boosting assembly 6, a second pressure-boosting assembly 7, and a third pressure-boosting assembly 8 are provided between the regenerative assembly 5 and the steam turbine 2.

[0045] Reference Figure 1Boiler 1 includes a superheater 11 and a reheater 12. Superheater 11 is a heater that heats saturated steam into superheated steam at a certain temperature, and reheater 12 is a heater in boiler 1 that heats steam from turbine 2 into superheated steam. Superheater 11 is connected to the steam inlet of high-pressure cylinder 21 through main steam pipe 111, and the exhaust port of high-pressure cylinder 21 is connected to reheater 12 through a pipe. Reheater 12 is further connected to the steam inlet of intermediate-pressure cylinder 22 through a pipe.

[0046] Reference Figure 1 The exhaust port of the intermediate pressure cylinder 22 is connected to the inlet port of the low pressure cylinder 23 through a pipeline, and a control valve 223 is installed on the pipeline between the intermediate pressure cylinder 22 and the low pressure cylinder 23. This allows the exhaust steam from the high pressure cylinder 21 to enter the reheater 12 of the boiler 1 for heat absorption and quality improvement, and then enter the intermediate pressure cylinder 22 of the turbine 2 to do work. The exhaust steam from the intermediate pressure cylinder 22 enters the low pressure cylinder 23 of the turbine 2 to do work.

[0047] Reference Figure 1 The exhaust port of low-pressure cylinder 23 is connected to the steam inlet of turbine condenser 4, allowing steam to enter and condense into condensate. The drain port of turbine condenser 4 is connected to regenerative assembly 5. Specifically, regenerative assembly 5 includes, in sequence, a condensate pump 51, a first low-pressure heater 52, a second low-pressure heater 53, a third low-pressure heater 54, a deaerator 55, a feedwater pump 56, a first high-pressure heater 57, a second high-pressure heater 58, and a third high-pressure heater 59. The drain port of the third high-pressure heater 59 is connected to boiler superheater 11. This allows the condensate to be heated in stages before becoming boiler feedwater, which then enters boiler 1 and is further heated by superheater 11.

[0048] For details, please refer to [reference]. Figure 2 In this embodiment, the high-pressure cylinder 21 includes two extraction ports: a first-stage extraction port 211 and a second-stage extraction port 212; the intermediate-pressure cylinder 22 includes two extraction ports: a third-stage extraction port 221 and a fourth-stage extraction port 222; and the low-pressure cylinder 23 includes three extraction ports: a fifth-stage extraction port 231, a sixth-stage extraction port 232, and a seventh-stage extraction port 233. Due to the different positions of the extraction ports, the pressure of the first-stage, second-stage, third-stage, fourth-stage, fifth-stage, sixth-stage, and seventh-stage extraction ports gradually decreases. In other embodiments, the number of extraction ports can be adjusted according to actual needs; for example, the intermediate-pressure cylinder 22 may include three extraction ports, and the low-pressure cylinder 23 may include two extraction ports.

[0049] Reference Figure 1The first booster assembly 6 includes a first low-pressure heater booster 61 and a first extraction steam pipe 62. The power steam inlet of the first low-pressure heater booster 61 is connected to the fourth extraction port 222 of the intermediate-pressure cylinder 22. The suction port of the first low-pressure heater booster 61 is connected to the seventh extraction port 233 of the low-pressure cylinder 23 via the first extraction steam pipe 62. The steam inlet of the first low-pressure heater 52 is connected to the exhaust port of the first low-pressure heater booster 61. A first high-pressure steam regulating valve 63 is installed on the pipe between the fourth extraction port 222 of the intermediate-pressure cylinder 22 and the power steam inlet of the first low-pressure heater booster 61. A first low-pressure steam regulating valve 64 is installed on the first extraction steam pipe 62 near the suction port of the first low-pressure heater booster 61. In addition, the first extraction steam pipe 62 is also connected to the first low-pressure heater 52 via a first regulating pipe 65, on which a seven-stage extraction steam regulating valve 66 is installed.

[0050] Reference Figure 1 The steam inlet of the second low-pressure heater 53 is connected to the sixth extraction port 232 of the low-pressure cylinder 23 via a second extraction steam pipe 531, which is equipped with a six-stage extraction steam regulating valve 532. The steam inlet of the third low-pressure heater 54 is connected to the fifth extraction port 231 of the low-pressure cylinder 23 via a third extraction steam pipe 541, which is equipped with a five-stage extraction steam regulating valve 542.

[0051] Reference Figure 1 The second booster assembly 7 includes a deaerator booster 71 and a fourth extraction steam pipe 72. The power steam inlet of the deaerator booster 71 is connected to the second-stage extraction port 212 of the high-pressure cylinder 21. The suction port of the deaerator booster 71 is connected to the fourth-stage extraction port 222 of the intermediate-pressure cylinder 22 via the fourth extraction steam pipe 72. The steam inlet of the deaerator 55 is connected to the exhaust port of the deaerator booster 71. A second high-pressure steam regulating valve 73 is installed on the pipe between the second-stage extraction port 212 of the high-pressure cylinder 21 and the power steam inlet of the deaerator booster 71. A second low-pressure steam regulating valve 74 is installed on the fourth extraction steam pipe 72 near the suction port of the deaerator booster 71. In addition, the fourth extraction steam pipe 72 is also directly connected to the deaerator 55 via a second regulating pipe 75, on which a four-stage extraction steam regulating valve 76 is installed.

[0052] Reference Figure 1 The steam inlet of the No. 1 high-pressure heater 57 is connected to the third-stage extraction port 221 of the intermediate-pressure cylinder 22 via a fifth extraction steam pipe 571, which is equipped with a three-stage extraction steam regulating valve 572. The steam inlet of the No. 2 high-pressure heater 58 is connected to the second-stage extraction port 212 of the high-pressure cylinder 21 via a sixth extraction steam pipe 581, which is equipped with a second-stage extraction steam regulating valve 582.

[0053] Reference Figure 1The third booster assembly 8 includes a third high-pressure heater booster 81, a branch pipe 82, and a seventh extraction pipe 83. The power steam inlet of the third high-pressure heater booster 81 is connected to the main steam pipe 111 via the branch pipe 82. A third high-pressure steam regulating valve 84 is installed on the branch pipe 82. The suction port of the third high-pressure heater booster 81 is connected to the first extraction port 211 of the high-pressure cylinder 21 via the seventh extraction pipe 83. A third low-pressure steam regulating valve 85 is installed on the seventh extraction pipe 83 near the suction port of the third high-pressure heater booster 81. Additionally, the seventh extraction pipe 83 is also connected to the third high-pressure heater 59 via a third regulating pipe 86. A first extraction regulating valve 87 is installed on the first regulating pipe 65.

[0054] The implementation principle of a turbine regenerative system according to an embodiment of this application is as follows: The steam-water circulation process of turbine group 2 is as follows: After the feedwater of boiler 1 is heated to the main steam parameters in boiler 1 superheater 11, it enters high-pressure cylinder 21 through main steam pipeline 111 to do work. The exhaust steam from high-pressure cylinder 21 enters boiler 1 reheater 12 to absorb heat and improve quality, and then enters intermediate-pressure cylinder 22 to do work. The exhaust steam from intermediate-pressure cylinder 22 enters low-pressure cylinder 23 to do work, and then enters turbine condenser 4. In turbine condenser 4, the steam is cooled and condensed into condensate. The condensate first enters condensate pump 51 for pressurization, and then enters low-pressure heater 52, low-pressure heater 53, and low-pressure heater 54 for heating in stages. Then it passes through deaerator 55 for deoxygenation, and then is pressurized again by feedwater pump 56, and then enters high-pressure heater 57, high-pressure heater 58, and high-pressure heater 59 for heating in stages, and finally enters boiler 1.

[0055] When in deep peak shaving condition, the first-stage extraction steam regulating valve 87, the fourth-stage extraction steam regulating valve 76, and the seventh-stage extraction steam regulating valve 66 are all closed, while the second-stage extraction steam regulating valve 582, the third-stage extraction steam regulating valve 572, the fifth-stage extraction steam regulating valve 542, the sixth-stage extraction steam regulating valve 532, the first high-pressure steam regulating valve 63, the first low-pressure steam regulating valve 64, the second high-pressure steam regulating valve 73, the third low-pressure steam regulating valve 85, the third high-pressure steam regulating valve 84, and the third low-pressure steam regulating valve 85 are all open, thus enabling the first booster assembly 6, the second booster assembly 7, and the third booster assembly 8 to operate.

[0056] When operating under non-deep peak-shaving conditions, the first high-pressure steam regulating valve 63, the first low-pressure steam regulating valve 64, the second high-pressure steam regulating valve 73, the second low-pressure steam regulating valve 74, the third high-pressure steam regulating valve 84, and the third low-pressure steam regulating valve 85 are all closed, causing the first booster assembly 6, the second booster assembly 7, and the third booster assembly 8 to be out of operation. The first-stage extraction steam regulating valve 87, the second-stage extraction steam regulating valve 582, the third-stage extraction steam regulating valve 572, the fourth-stage extraction steam regulating valve 76, the fifth-stage extraction steam regulating valve 542, the sixth-stage extraction steam regulating valve 532, and the seventh-stage extraction steam regulating valve 66 are all open, achieving normal heat exchange.

[0057] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A steam turbine regenerative system, comprising a boiler (1), a steam turbine (2) and a steam turbine condenser (4), wherein the steam turbine (2) comprises a high-pressure cylinder (21), an intermediate-pressure cylinder (22) and a low-pressure cylinder (23), wherein the boiler (1) is connected to the high-pressure cylinder (21) via a main steam pipeline (111), and the high-pressure cylinder (21), the intermediate-pressure cylinder (22), the low-pressure cylinder (23) and the steam turbine condenser (4) are sequentially connected via pipelines; Its features are: It also includes a third booster assembly (8) and a regenerator assembly (5). The third booster assembly (8) includes a third high-pressure heater steam generator (81), a diversion pipe (82) and a seventh extraction pipe (83). The regenerator assembly (5) includes a third high-pressure heater (59). The power steam inlet of the No. 3 high-pressure heater steam generator (81) is connected to the main steam pipeline (111) through the branch pipeline (82), and the suction port of the No. 3 high-pressure heater steam generator (81) is connected to the first extraction port (211) of the high-pressure cylinder (21) through the seventh extraction pipeline (83). The steam inlet of the No. 3 high-pressure heater (59) is connected to the steam outlet of the No. 3 high-pressure heater booster (81), the water inlet of the No. 3 high-pressure heater (59) is connected to the drain outlet of the steam turbine condenser (4), and the drain outlet of the No. 3 high-pressure heater (59) is connected to the water inlet of the boiler (1). It also includes a second booster assembly (7), which includes a deaerator steam generator (71), a fourth extraction steam pipe (72), a second high-pressure steam regulating valve (73), a second low-pressure steam regulating valve (74), and a four-stage extraction steam regulating valve (76). The regenerative assembly (5) also includes a deaerator (55), which is located between the turbine condenser (4) and the third high-pressure heater (59). The power steam inlet of the deaerator booster (71) is connected to the second-stage extraction port (212) of the high-pressure cylinder (21). The suction port of the deaerator booster (71) is connected to the fourth-stage extraction port (222) of the intermediate-pressure cylinder (22) through the fourth extraction pipe (72). The steam inlet of the deaerator (55) is connected to the exhaust port of the deaerator booster (71). The second high-pressure steam regulating valve (73) is located between the second-stage extraction port (212) of the high-pressure cylinder (21) and the power steam inlet of the deaerator booster (71). The second low-pressure steam regulating valve (74) is located on the fourth extraction pipe (72) near the suction port of the deaerator booster (71). The fourth extraction pipe (72) is also directly connected to the steam inlet of the deaerator (55) through the second regulating pipe (75). The fourth-stage extraction steam regulating valve (76) is located on the second regulating pipe (75). It also includes a first booster assembly (6), which includes a first low-pressure heater booster (61) and a first extraction steam pipe (62). The regenerative assembly (5) also includes a first low-pressure heater (52), which is located between the turbine condenser (4) and the third high-pressure heater (59). The power steam inlet of the first low-pressure heater booster (61) is connected to the fourth extraction port (222) of the intermediate-pressure cylinder (22), the suction port of the first low-pressure heater booster (61) is connected to the seventh extraction port (233) of the low-pressure cylinder (23) through the first extraction pipe (62), and the steam inlet of the first low-pressure heater (52) is connected to the exhaust port of the first low-pressure heater booster (61).

2. The steam turbine regenerative system according to claim 1, characterized in that: The third booster assembly (8) also includes a third high-pressure steam regulating valve (84), a third low-pressure steam regulating valve (85), and a first-stage extraction steam regulating valve (87). The third high-pressure steam regulating valve (84) is located on the diversion pipe (82), and the third low-pressure steam regulating valve (85) is located on the seventh extraction steam pipe (83) near the suction port of the third high-pressure heater booster (81). The seventh extraction steam pipe (83) is also directly connected to the steam inlet of the third high-pressure heater (59) through the third regulating pipe (86), and the first extraction steam regulating valve (87) is installed on the third regulating pipe (86).

3. The steam turbine regenerative system according to claim 1, characterized in that: The first booster assembly (6) also includes a first high-pressure steam regulating valve (63), a first low-pressure steam regulating valve (64) and a seven-stage extraction steam regulating valve (66). The first high-pressure steam regulating valve (63) is located between the four-stage extraction steam port (222) of the intermediate-pressure cylinder (22) and the power steam inlet of the first low-pressure heater booster (61). The first low-pressure steam regulating valve (64) is located on the first extraction steam pipe (62) near the suction port of the first low-pressure heater booster (61). The first extraction steam pipe (62) is also directly connected to the steam inlet of the first low-pressure heater (52) through the first regulating pipe (65), and the seven-stage extraction steam regulating valve (66) is installed on the first regulating pipe (65).

4. A steam turbine regenerative system according to claim 1, characterized in that: The regenerative assembly (5) also includes a second low-pressure heater (53) and a second extraction steam pipe (531). The second low-pressure heater (53) is located between the first low-pressure heater (52) and the third high-pressure heater (59). One end of the second extraction steam pipe (531) is connected to the six-section extraction steam port (232) of the low-pressure cylinder (23), and the other end is connected to the steam inlet of the second low-pressure heater (53). A six-section extraction steam regulating valve (532) is provided on the second extraction steam pipe (531).

5. A steam turbine regenerative system according to claim 4, characterized in that: The regenerative assembly (5) also includes a third low-pressure heater (54) and a third extraction steam pipe (541). The third low-pressure heater (54) is located between the second low-pressure heater (53) and the third high-pressure heater (59). One end of the third extraction steam pipe (541) is connected to the five-stage extraction steam port (231) of the low-pressure cylinder (23), and the other end is connected to the steam inlet of the third low-pressure heater (54). A five-stage extraction steam regulating valve (542) is provided on the third extraction steam pipe (541).

6. A steam turbine regenerative system according to claim 5, characterized in that: The regenerative assembly (5) also includes a first high-pressure heater (57) and a fifth extraction steam pipe (571). The first high-pressure heater (57) is located between the third high-pressure heater (59) and the third low-pressure heater (54). One end of the fifth extraction steam pipe (571) is connected to the three-section extraction steam port (221) of the intermediate pressure cylinder (22), and the other end is connected to the steam inlet of the first high-pressure heater (57). A three-section extraction steam regulating valve (572) is provided on the fifth extraction steam pipe (571).

7. A steam turbine regenerative system according to claim 6, characterized in that: The regenerative assembly (5) also includes a second high-pressure heater (58) and a sixth extraction steam pipe (581). The second high-pressure heater (58) is located between the third high-pressure heater (59) and the first high-pressure heater (57). One end of the sixth extraction steam pipe (581) is connected to the second extraction steam port (212) of the high-pressure cylinder (21), and the other end is connected to the steam inlet of the second high-pressure heater (58). A second extraction steam regulating valve (582) is provided on the sixth extraction steam pipe (581).

Images