Ultra-wide load combined cycle unit based on bypass ventilation and hydrogen energy storage

Abstract

The utility model relates to the technical field of combined cycle power generation, in particular to an ultra-wide load combined cycle unit based on bypass ventilation and hydrogen energy storage, which comprises a gas-steam combined cycle unit, a bypass unit and an independent starting system. The independent starting system is connected with the bypass unit and provides steam power generation for the bypass unit, the bypass unit is used for flexible peak regulation, ultralow-load operation is achieved, and the high-load condition is coped with, and the independent starting system is used for black starting of the system; when the power load is increased, the boiler is started to participate in overheat peak regulation, and due to the fact that the bypass steam flow is low, in order to achieve high output power, a variable-speed centripetal turbine and a permanent magnet motor can be adopted to better adapt to variable-speed output, and the system maintains high efficiency; the system structure of the gas-steam combined cycle unit can be further improved, and the gas-steam combined cycle unit can operate independently, stably and efficiently.

Description

Technical Field

[0001] The utility model relates to the technical field of combined cycle power generation, in particular to an ultra-wide load combined cycle unit based on a bypass turbine and hydrogen energy storage. Background Art

[0002] High-quality, clean fuel, natural gas, can partially replace coal. The use of natural gas as a clean energy source in combined cycle power generation will effectively promote the development of the clean power industry. The combined cycle (CC) is a new power generation technology featuring fast gas turbine startup, improved thermal efficiency, and significant peaking capability. In recent years, power plants have seen rapid iterations of gas turbines, with design pressure ratios and initial temperatures continuously rising, leading to increased efficiency. Furthermore, compared to coal-fired power generation equipment, the power generation efficiency of gas-fired combined power generation units has been significantly improved. The flexibility and efficiency of gas-steam combined cycle units have made them increasingly important in power systems.

[0003] Although the gas-steam combined cycle unit has many advantages, due to the complexity of the gas-steam combined cycle unit and the imperfect system structure, the existing gas-steam combined cycle unit still has the defect of being unable to operate independently, stably and efficiently during actual use. Therefore, further research and technological innovation are required on the existing technology. Utility Model Content

[0004] The purpose of the present utility model is to address the above-mentioned deficiencies and provide an ultra-wide load combined cycle unit based on a bypass turbine and hydrogen energy storage, which can further improve the system structure of the gas-steam combined cycle unit and enable the gas-steam combined cycle unit to operate independently, stably and efficiently.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0006] An ultra-wide load combined cycle unit based on a bypass turbine and hydrogen energy storage includes a gas-steam combined cycle unit, a bypass unit and an independent starting system. The gas-steam combined cycle unit is used to complete the power generation and heating tasks under rated load and provide steam power generation for the bypass unit. The bypass unit is used for flexible peak regulation to achieve ultra-low load operation and cope with high load conditions. The independent starting system is used to enable the system to be black started.

[0007] Furthermore, the gas-steam combined cycle unit includes a waste heat boiler, a gas turbine, a compressor, a steam turbine high-pressure cylinder, a steam turbine intermediate-pressure cylinder, a first generator, an S clutch and a steam turbine low-pressure cylinder;

[0008] The bypass unit includes a synchronous generator, a permanent magnet generator, a fourth regulating valve, a fifth regulating valve, a sixth regulating valve, a variable speed centripetal turbine and a variable speed axial turbine;

[0009] Air enters the compressor inlet L through the air filter and is pressurized. Natural gas from the natural gas pressure regulating station enters the end of the compressor. After the air and natural gas are mixed and burned in the compressor, the high-temperature flue gas enters the gas turbine to perform work, and the exhaust gas enters the waste heat boiler. The condensate pump is connected to the waste heat boiler's feed water inlet g. After being heated in the waste heat boiler, it is connected to the deaerator through outlet a. The deaerator outlet feed water is divided into three streams, which pass through the low-pressure feed water pump, medium-pressure feed water pump, and high-pressure feed water pump respectively, and return to the waste heat boiler through the waste heat boiler inlets b, d, and e respectively. After being heated, it flows out from the waste heat boiler outlets j, i, and h respectively. Among them, the high-pressure steam flowing out of outlet j enters the high-pressure cylinder through inlet n.

[0010] The intermediate-pressure steam flowing out of i passes through the third regulating valve and merges with the steam at the high-pressure cylinder outlet m before entering the intermediate-pressure cylinder through inlet o. The steam flowing out of the intermediate-pressure cylinder is divided into three streams. The first stream enters the low-pressure cylinder through p, the second stream enters the variable-speed centrifugal turbine through s, and then passes through the outlet t of the variable-speed centrifugal turbine through inlet u to enter the constant-speed axial flow turbine. The constant-speed axial flow turbine is connected to the inlet w of the condenser through outlet v. The third stream merges with the steam flowing out of the waste heat boiler outlet h through the second regulating valve and enters the independent starting system.

[0011] After flowing out of the low-pressure cylinder, it is discharged through the condenser outlet q, and after being pressurized by the condensate pump, it enters the waste heat boiler through g to carry out the next cycle; the steam at the waste heat boiler outlet c is used as the feed water heating steam for the deaerator. The variable speed centripetal turbine is connected to the permanent magnet generator; the fixed speed axial flow turbine is connected to the synchronous generator.

[0012] Furthermore, the gas-steam combined cycle unit includes a waste heat boiler, a gas turbine, a compressor, a steam turbine high-pressure cylinder, a steam turbine intermediate-pressure cylinder, a first generator, an S clutch and a steam turbine low-pressure cylinder;

[0013] The bypass unit includes a synchronous generator, a fourth regulating valve, a sixth regulating valve and a variable speed axial flow turbine;

[0014] Air enters the compressor inlet L through the air filter and is pressurized. Natural gas from the natural gas pressure regulating station enters the end of the compressor. After the air and natural gas are mixed and burned in the compressor, the high-temperature flue gas enters the gas turbine to perform work, and the exhaust gas enters the waste heat boiler. The condensate pump is connected to the waste heat boiler's feed water inlet g. After being heated in the waste heat boiler, it is connected to the deaerator through outlet a. The deaerator outlet feed water is divided into three streams, which pass through the low-pressure feed water pump, medium-pressure feed water pump, and high-pressure feed water pump respectively, and return to the waste heat boiler through the waste heat boiler inlets b, d, and e respectively. After being heated, it flows out from the waste heat boiler outlets j, i, and h respectively. Among them, the high-pressure steam flowing out of outlet j enters the high-pressure cylinder through inlet n.

[0015] The intermediate-pressure steam flowing out of i passes through the third regulating valve and merges with the steam at the high-pressure cylinder outlet m before entering the intermediate-pressure cylinder from inlet o. The steam flowing out of the intermediate-pressure cylinder is divided into three streams. The first stream enters the low-pressure cylinder from p, the second stream enters the variable-speed axial flow turbine from u, and enters the condenser from the variable-speed axial flow turbine outlet v through inlet w. The third stream merges with the steam flowing out of the waste heat boiler outlet h through the second regulating valve and enters the independent starting system.

[0016] After flowing out of the low-pressure cylinder, it is discharged through the condenser outlet q, and after being pressurized by the condensate pump, it enters the waste heat boiler through g to carry out the next cycle; the steam at the waste heat boiler outlet c is used as the feed water heating steam for the deaerator, and the fixed-speed axial flow turbine is connected to the synchronous generator.

[0017] Furthermore, the independent starting system includes a desalted water source, a starting boiler, a plant auxiliary steam header, a water electrolysis hydrogen production module, a hydrogen storage tank and an oxygen storage tank. The desalted water in the desalted water source is connected to the starting boiler inlet aa from the outlet y through the eighth regulating valve, and enters the starting boiler from aa, and is connected to the plant auxiliary steam header inlet ad from the outlet ab. The steam flowing out of the waste heat boiler outlet h is combined with the steam flowing out of the medium pressure cylinder and then passes through the seventh regulating valve to enter the plant auxiliary steam header from the inlet ae. The steam is connected to various steam-consuming equipment from the plant auxiliary steam header outlet af. Part of the steam at the outlet af is mixed with the steam flowing through the fifth regulating valve through the inlet x and the sixth regulating valve and then enters the centripetal turbine inlet s. The output end of the water electrolysis hydrogen production module is connected to the hydrogen storage tank and the oxygen storage tank respectively. The output ends of the hydrogen storage tank and the oxygen storage tank are merged through a pipeline and enter the starting boiler from the inlet ag. The outlet k of the natural gas pressure regulating station is connected to the inlet of the starting boiler through the first regulating valve, and the outlet ac of the starting boiler is connected to the inlet f of the waste heat boiler.

[0018] Furthermore, the independent startup system includes a desalted water source, a startup boiler, a plant auxiliary steam header, a water electrolysis hydrogen production module, a hydrogen storage tank, and an oxygen storage tank. The desalted water in the desalted water source is connected from outlet y to the startup boiler inlet aa via an eighth regulating valve and enters the startup boiler from aa. The desalted water is connected from outlet ab to the plant auxiliary steam header inlet ad. The steam flowing out of the waste heat boiler outlet h is combined with the steam flowing out of the intermediate pressure cylinder and then passes through a seventh regulating valve to enter the plant auxiliary steam header from inlet ae. The steam is connected to various steam-consuming equipment from the plant auxiliary steam header outlet af. Part of the steam from outlet af is mixed with the steam discharged from the constant-speed axial flow turbine via inlet x and a sixth regulating valve and then enters the condenser via inlet w. The output end of the water electrolysis hydrogen production module is connected to the hydrogen storage tank and the oxygen storage tank, respectively. The output ends of the hydrogen storage tank and the oxygen storage tank are combined through a pipeline and enter the startup boiler from inlet ag. The outlet k of the natural gas pressure regulating station is connected to the inlet of the startup boiler via a first regulating valve. The outlet ac of the startup boiler is connected to the inlet f of the waste heat boiler.

[0019] Furthermore, the independent startup system includes a desalted water source, a startup boiler and a plant auxiliary steam header. The desalted water in the desalted water source enters the startup boiler from the outlet aa through the eighth regulating valve, and is connected to the plant auxiliary steam header inlet af from the outlet ad. The steam flowing out of the waste heat boiler outlet h is merged and enters the plant auxiliary steam header from the inlet ag through the seventh regulating valve. The steam is connected to various steam-consuming equipment from the plant auxiliary steam header outlet ah. Part of the steam at the outlet ah is mixed with the steam discharged from the constant-speed axial flow turbine through the inlet x and the sixth regulating valve, and then enters the condenser through the inlet w. The outlet k of the natural gas pressure regulating station is connected to the inlet of the startup boiler through the first regulating valve, and the outlet ae of the startup boiler is connected to the inlet f of the waste heat boiler.

[0020] The beneficial effects of the utility model are:

[0021] In practical applications, by coupling and controlling the gas-steam combined cycle generator set and the bypass steam turbine generator set, when the unit enters the deep peak-shaving stage and the unit load is lower than 30% of the rated load, for the safety of the low-pressure cylinder, the cylinder can be cut off and the bypass unit can be started and connected to the grid. At this time, the exhaust steam from the intermediate-pressure cylinder can directly enter the bypass steam turbine and then enter the condenser for condensation. Since the bypass steam turbine is designed for combined cycle units below 30% load, it can operate safely at around 10% load of the combined cycle unit. In addition, during low-load periods, the water electrolysis hydrogen production module can achieve negative power regulation of the system, greatly widening the regulation range of the system. When the power load increases, the boiler is started to participate in over-generation peak-shaving. Since the bypass steam flow is low, in order to achieve higher output power, a variable speed centripetal turbine + permanent magnet motor can be used to better adapt to variable speed output and maintain higher system efficiency. This application can further improve the system structure of the gas-steam combined cycle unit, so that the gas-steam combined cycle unit can operate independently, stably and efficiently. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic structural diagram of the first embodiment of the present invention;

[0023] Figure 2 This is a schematic structural diagram of Example 2 of the present utility model;

[0024] Figure 3 This is a structural diagram of the third embodiment of the present invention.

[0025] Figure 1: Waste heat boiler, 2. Gas turbine, 3. Compressor, 4. Steam turbine high-pressure cylinder, 5. Steam turbine intermediate-pressure cylinder, 6. First generator, 7. 3S clutch, 8. Steam turbine low-pressure cylinder, 9. Condenser, 10. Variable speed synchronous / permanent magnet generator, 11. Permanent magnet generator, 12. Fourth regulating valve, 13. Fifth regulating valve, 14. Sixth regulating valve, 15. Variable speed centrifugal turbine, 16. Variable speed axial turbine, 17. Deaerator, 18. Low-pressure feed water pump, 19 Medium-pressure feedwater pump, 20. High-pressure feedwater pump, 21. First regulating valve, 22. First transformer, 23. Second transformer, 24. High-voltage power grid, 25. Natural gas pressure regulating station, 26. Air filter, 27. Second regulating valve, 28. Third regulating valve, 29. Condensate pump, 30. Desalted water source, 31. Eighth regulating valve, 32. Start-up boiler, 33. Auxiliary steam header, 34. Seventh regulating valve, 35. Hydrogen production by water electrolysis, 36. H2 storage tank, 37. O2 storage tank;

[0026] a~ai are the import and export numbers of each equipment. DETAILED DESCRIPTION

[0027] Example 1:

[0028] like Figure 1 As shown, an ultra-wide load combined cycle unit based on a bypass turbine and hydrogen energy storage includes a gas-steam combined cycle unit, a bypass unit, and an independent starting system. The gas-steam combined cycle unit is used to complete power generation and heating tasks under rated load and provide steam power generation for the bypass unit. The bypass unit is used for flexible peak regulation to achieve ultra-low load operation and cope with high load conditions. The independent starting system is used to perform a black start of the system.

[0029] The gas-steam combined cycle unit includes a waste heat boiler 1, a gas turbine 2, a compressor 3, a steam turbine high-pressure cylinder 4, a steam turbine intermediate-pressure cylinder 5, a first generator 6, a 3S clutch 7 and a steam turbine low-pressure cylinder 8;

[0030] The bypass unit includes a synchronous generator 10, a permanent magnet generator 11, a fourth regulating valve 12, a fifth regulating valve 13, a sixth regulating valve 14, a variable speed centripetal turbine 15 and a variable speed axial turbine 16;

[0031] Air enters the compressor 3 from inlet L through air filter 26 and is pressurized. Natural gas from the natural gas pressure regulating station 25 enters the end of the compressor 3. After the air and natural gas are mixed and burned in the compressor 3, the high-temperature flue gas enters the gas turbine 2 to perform work, and the exhaust gas enters the waste heat boiler 1. The condensate pump 29 is connected to the feed water inlet g of the waste heat boiler 1. After being heated by the waste heat boiler 1, it is connected to the deaerator 17 from outlet a. The feed water at the outlet of the deaerator 17 is split into three streams, which are respectively passed through the low-pressure feed water pump 18, the medium-pressure feed water pump 19, and the high-pressure feed water pump 20. The water returns to the waste heat boiler 1 from inlets b, d, and e of the waste heat boiler 1, and after being heated, it flows out from outlets j, i, and h of the waste heat boiler 1. The high-pressure steam flowing out of outlet j enters the high-pressure cylinder 4 through inlet n.

[0032] The intermediate-pressure steam flowing out of i passes through the third regulating valve 28 and merges with the steam at the outlet m of the high-pressure cylinder 4 before entering the intermediate-pressure cylinder 5 through the inlet o. The steam flowing out of the intermediate-pressure cylinder 5 is divided into three streams. The first stream enters the low-pressure cylinder 8 through p, the second stream enters the variable-speed centrifugal turbine 15 through s, passes through the outlet t of the variable-speed centrifugal turbine 15, and enters the constant-speed axial flow turbine 16 through the inlet u. The constant-speed axial flow turbine 16 is connected to the inlet w of the condenser 9 through the outlet v. The third stream merges with the steam flowing out of the outlet h of the waste heat boiler 1 through the second regulating valve 27 and enters the independent starting system.

[0033] In this embodiment, the first stage is a variable-speed centripetal turbine 15. Steam enters the centripetal turbine 15 radially from inlet s, exits the centripetal turbine 15 axially from outlet t, enters the constant-speed axial turbine 16 from inlet u, exits from outlet v, and enters inlet w. The steam enters the condenser 9 in parallel with the low-pressure cylinder outlet, sharing the same condenser. This increases the exhaust area and improves the system's overload capacity.

[0034] After flowing out of the low-pressure cylinder 8, it is discharged through the outlet q of the condenser 9, and after being pressurized by the condensate pump 29, it enters the waste heat boiler 1 through the outlet g to start the next cycle. The steam at the outlet c of the waste heat boiler 1 is used as the feed water heating steam for the deaerator 17. The variable speed centripetal turbine 15 is connected to the permanent magnet generator 11; the fixed speed axial flow turbine 16 is connected to the synchronous generator 10.

[0035] In this embodiment, the variable speed centripetal turbine 15 is connected to the permanent magnet generator 11 to achieve high speed and high power DC output, and the fixed speed axial flow turbine 16 is connected to the synchronous generator 10 to achieve stable system output. The combined cycle unit can be arranged in a single shaft or a multi-shaft arrangement.

[0036] The independent startup system includes a desalted water source 30, a startup boiler 32, a plant auxiliary steam header 33, a water electrolysis hydrogen production module 35, a hydrogen storage tank 36, and an oxygen storage tank 37. The desalted water in the desalted water source 30 is connected from the outlet y to the inlet aa of the startup boiler 32 through the eighth regulating valve 31, and enters the startup boiler 32 from aa, and is connected from the outlet ab to the inlet ad of the plant auxiliary steam header 33. The steam flowing out of the outlet h of the waste heat boiler 1 and the steam flowing out of the medium pressure cylinder 5 are combined and then pass through the seventh regulating valve 34 to enter the plant auxiliary steam header 33 from the inlet ae. The steam flows from the plant auxiliary steam header Outlet af of 33 is connected to various steam-consuming equipment. Part of the steam at outlet af is mixed with the steam flowing through the fifth regulating valve 13 through the inlet x and the sixth regulating valve 14, and then enters the inlet s of the centripetal turbine 15. The output end of the water electrolysis hydrogen production module 35 is respectively connected to the hydrogen storage tank 36 and the oxygen storage tank 37. The output ends of the hydrogen storage tank 36 and the oxygen storage tank 37 are merged through a pipeline and enter the startup boiler 32 through the inlet ag. The outlet k of the natural gas pressure regulating station 25 is connected to the inlet of the startup boiler 32 through the first regulating valve 21. The outlet ac of the startup boiler 32 is connected to the inlet f of the waste heat boiler 1.

[0037] In this embodiment, the water electrolysis hydrogen production module 35 is connected to the power grid and can realize power consumption according to the load of the power grid; the hydrogen storage tank 36 and the oxygen storage tank 37 store the H2 and O2 produced by the water electrolysis hydrogen production module 35, and automatically start the boiler and automatically go to the waste heat boiler 1 to realize two-way fuel compensation; among them, the first generator 6, the synchronous generator 10 and the permanent magnet generator 11 are connected to the second transformer 23 through the first transformer 22, the water electrolysis hydrogen production module 35 is connected to the second transformer 23, and the second transformer 23 is connected to the high-voltage power grid 24.

[0038] Example 2:

[0039] like Figure 2 As shown, an ultra-wide load combined cycle unit based on a bypass turbine and hydrogen energy storage includes a gas-steam combined cycle unit, a bypass unit, and an independent starting system. The gas-steam combined cycle unit is used to complete power generation and heating tasks under rated load and provide steam power generation for the bypass unit. The bypass unit is used for flexible peak regulation to achieve ultra-low load operation and cope with high load conditions. The independent starting system is used to perform a black start of the system.

[0040] The gas-steam combined cycle unit includes a waste heat boiler 1, a gas turbine 2, a compressor 3, a steam turbine high-pressure cylinder 4, a steam turbine intermediate-pressure cylinder 5, a first generator 6, a 3S clutch 7 and a steam turbine low-pressure cylinder 8;

[0041] The bypass unit includes a synchronous generator 10, a fourth regulating valve 12, a sixth regulating valve 14 and a variable speed axial flow turbine 16;

[0042] Air enters the compressor 3 from inlet L through air filter 26 and is pressurized. Natural gas from the natural gas pressure regulating station 25 enters the end of the compressor 3. After the air and natural gas are mixed and burned in the compressor 3, the high-temperature flue gas enters the gas turbine 2 to perform work, and the exhaust gas enters the waste heat boiler 1. The condensate pump 29 is connected to the feed water inlet g of the waste heat boiler 1. After being heated by the waste heat boiler 1, it is connected to the deaerator 17 from outlet a. The feed water at the outlet of the deaerator 17 is split into three streams, which are respectively passed through the low-pressure feed water pump 18, the medium-pressure feed water pump 19, and the high-pressure feed water pump 20. The water returns to the waste heat boiler 1 from inlets b, d, and e of the waste heat boiler 1, and after being heated, it flows out from outlets j, i, and h of the waste heat boiler 1. The high-pressure steam flowing out of outlet j enters the high-pressure cylinder 4 through inlet n.

[0043] The intermediate-pressure steam flowing out of channel i passes through the third regulating valve 28 and merges with the steam at the outlet m of the high-pressure cylinder 4 before entering the intermediate-pressure cylinder 5 through the inlet o. The steam flowing out of the intermediate-pressure cylinder 5 is divided into three streams. The first stream enters the low-pressure cylinder 8 through p, the second stream enters the variable-speed axial flow turbine 16 through u, and then enters the condenser 9 from the outlet v of the variable-speed axial flow turbine 16 through the inlet w. The third stream merges with the steam flowing out of the outlet h of the waste heat boiler 1 through the second regulating valve 27 and enters the independent starting system.

[0044] After flowing out of the low-pressure cylinder 8, it is discharged through the outlet q of the condenser 9, and after being pressurized by the condensate pump 29, it enters the waste heat boiler 1 through the outlet g to start the next cycle. The steam at the outlet c of the waste heat boiler 1 is used as the feed water heating steam for the deaerator 17. The fixed-speed axial flow turbine 16 is connected to the synchronous generator 10.

[0045] In this embodiment, a constant-speed axial flow turbine 16 is connected to a synchronous generator 10 to achieve a stable system output, wherein the combined cycle unit can be arranged in a single shaft or a multi-shaft arrangement;

[0046] The independent startup system includes a desalted water source 30, a startup boiler 32, a plant auxiliary steam header 33, a water electrolysis hydrogen production module 35, a hydrogen storage tank 36, and an oxygen storage tank 37. The desalted water in the desalted water source 30 is connected from the outlet y to the inlet aa of the startup boiler 32 through the eighth regulating valve 31, and enters the startup boiler 32 from aa, and is connected from the outlet ab to the inlet ad of the plant auxiliary steam header 33. The steam flowing out of the outlet h of the waste heat boiler 1 and the steam flowing out of the medium pressure cylinder 5 are combined and then pass through the seventh regulating valve 34 to enter the plant auxiliary steam header 33 from the inlet ae. The steam flows from the plant auxiliary steam header Outlet af of 33 is connected to various steam-consuming equipment. Part of the steam at outlet af is mixed with the steam discharged from the constant-speed axial flow turbine 16 through inlet x and the sixth regulating valve 14, and then enters the condenser 9 through inlet w. The output end of the water electrolysis hydrogen production module 35 is respectively connected to the hydrogen storage tank 36 and the oxygen storage tank 37. The output ends of the hydrogen storage tank 36 and the oxygen storage tank 37 are combined through a pipeline and enter the startup boiler 32 through inlet ag. The outlet k of the natural gas pressure regulating station 25 is connected to the inlet of the startup boiler 32 through the first regulating valve 21. The outlet ac of the startup boiler 32 is connected to the inlet f of the waste heat boiler 1.

[0047] In this embodiment, the startup boiler 32 is a dual-burner boiler that can take into account both natural gas and hydrogen fuels. The water electrolysis hydrogen production module 35 is connected to the power grid, which can realize hydrogen production and energy storage under low load of the system and adjust the output load of the system; the desalted water in the desalted water source 30 is connected from the outlet y to the inlet aa of the startup boiler 32, and enters the startup boiler 32 from aa, and is connected from the outlet ab to the inlet ad of the auxiliary steam header 33 of the plant. The other steam is exhausted from the medium pressure cylinder 5 and the outlet h of the low pressure feed water pump 18, and is connected to the inlet ae through the seventh regulating valve 34. The steam enters the auxiliary steam header 33, and is connected to various steam-consuming equipment from the outlet af of the auxiliary steam header 33. Part of the steam at the outlet af is mixed with the steam flowing through the fifth regulating valve 13 through the inlet x of the centripetal turbine 15 by the sixth regulating valve 14. The starting boiler 32 can serve as an auxiliary heat source when the system is fully powered, further increasing the amount of auxiliary steam, and enter the bypass system through the inlet x to perform work. Since the permanent magnet generator 11 and the synchronous generator 10 have a self-excited structure, they do not absorb reactive power from the power grid during startup and can therefore serve as a black start power source.

[0048] Example 3:

[0049] like Figure 3 As shown, an ultra-wide load combined cycle unit based on a bypass turbine and hydrogen energy storage includes a gas-steam combined cycle unit, a bypass unit, and an independent starting system. The gas-steam combined cycle unit is used to complete power generation and heating tasks under rated load and provide steam power generation for the bypass unit. The bypass unit is used for flexible peak regulation to achieve ultra-low load operation and cope with high load conditions. The independent starting system is used to perform a black start of the system.

[0050] The gas-steam combined cycle unit includes a waste heat boiler 1, a gas turbine 2, a compressor 3, a steam turbine high-pressure cylinder 4, a steam turbine intermediate-pressure cylinder 5, a first generator 6, a 3S clutch 7 and a steam turbine low-pressure cylinder 8;

[0051] The bypass unit includes a synchronous generator 10, a fourth regulating valve 12, a sixth regulating valve 14 and a variable speed axial flow turbine 16;

[0052] Air enters the compressor 3 from inlet L through air filter 26 and is pressurized. Natural gas from the natural gas pressure regulating station 25 enters the end of the compressor 3. After the air and natural gas are mixed and burned in the compressor 3, the high-temperature flue gas enters the gas turbine 2 to perform work, and the exhaust gas enters the waste heat boiler 1. The condensate pump 29 is connected to the feed water inlet g of the waste heat boiler 1. After being heated by the waste heat boiler 1, it is connected to the deaerator 17 from outlet a. The feed water at the outlet of the deaerator 17 is split into three streams, which are respectively passed through the low-pressure feed water pump 18, the medium-pressure feed water pump 19, and the high-pressure feed water pump 20. The water returns to the waste heat boiler 1 from inlets b, d, and e of the waste heat boiler 1, and after being heated, it flows out from outlets j, i, and h of the waste heat boiler 1. The high-pressure steam flowing out of outlet j enters the high-pressure cylinder 4 through inlet n.

[0053] The intermediate-pressure steam flowing out of channel i passes through the third regulating valve 28 and merges with the steam at the outlet m of the high-pressure cylinder 4 before entering the intermediate-pressure cylinder 5 through the inlet o. The steam flowing out of the intermediate-pressure cylinder 5 is divided into three streams. The first stream enters the low-pressure cylinder 8 through p, the second stream enters the variable-speed axial flow turbine 16 through u, and then enters the condenser 9 from the outlet v of the variable-speed axial flow turbine 16 through the inlet w. The third stream merges with the steam flowing out of the outlet h of the waste heat boiler 1 through the second regulating valve 27 and enters the independent starting system.

[0054] After flowing out of the low-pressure cylinder 8, it is discharged through the outlet q of the condenser 9, and after being pressurized by the condensate pump 29, it enters the waste heat boiler 1 through the outlet g to start the next cycle. The steam at the outlet c of the waste heat boiler 1 is used as the feed water heating steam for the deaerator 17. The fixed-speed axial flow turbine 16 is connected to the synchronous generator 10.

[0055] The independent startup system includes a desalted water source 30, a startup boiler 32, and a plant auxiliary steam header 33. The desalted water in the desalted water source 30 flows from outlet aa through the eighth regulating valve 31 into the startup boiler 32, and from outlet ad into the inlet af of the plant auxiliary steam header 33. The steam flowing out of the outlet h of the waste heat boiler 1 is combined and then flows through the seventh regulating valve 34 into the plant auxiliary steam header 33 from the inlet ag. The steam from the plant auxiliary steam header 33 is connected to various steam-consuming equipment at outlet ah. Part of the steam at outlet ah is mixed with the steam discharged from the constant-speed axial flow turbine 16 through the inlet x and the sixth regulating valve 14, and then enters the condenser 9 through the inlet w. The outlet k of the natural gas pressure regulating station 25 is connected to the inlet of the startup boiler 32 through the first regulating valve 21. The outlet ae of the startup boiler 32 is connected to the inlet f of the waste heat boiler 1.

[0056] In this embodiment, the first generator 6 and the synchronous generator 10 are connected to the high-voltage power grid 24 via a first transformer 22 and a second transformer 23 respectively.

[0057] This application couples and controls the gas-steam combined cycle generator set and the bypass steam turbine generator set. When the unit enters the deep peak-shaving stage and the unit load is lower than 30% of the rated load, for the safety of the low-pressure cylinder, the cylinder can be cut and the bypass unit can be started for grid-connected operation. At this time, the exhaust steam from the medium-pressure cylinder can directly enter the bypass steam turbine and then enter the condenser for condensation. Since the bypass steam turbine is designed for combined cycle units below 30% load, it can operate safely at around 10% load of the combined cycle unit, and in low-load periods, the water electrolysis hydrogen production module may achieve system negative power regulation, greatly widening the regulation range of the system. When the power load increases, the boiler is started to participate in super-generation peak-shaving. Since the bypass steam flow is low, in order to achieve higher output power, a variable speed centripetal turbine + permanent magnet motor can be used to better adapt to the variable speed output and maintain a higher efficiency of the system. It can further improve the system structure of the gas-steam combined cycle unit, so that the gas-steam combined cycle unit can operate independently, stably and efficiently.

[0058] The specific embodiments described herein are merely examples of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described, or replace them with similar methods without departing from the scope of the present invention.

Claims

1. An ultra-wide load combined cycle unit based on a bypass turbine and hydrogen energy storage, characterized by: It includes a gas-steam combined cycle unit, a bypass unit and an independent starting system. The gas-steam combined cycle unit is used to complete the power generation and heating tasks under rated load, and provide steam power generation for the bypass unit. The bypass unit is used for flexible peak regulation to achieve ultra-low load operation and cope with high load conditions. The independent starting system is used to enable the system to be black-started.

2. The ultra-wide load combined cycle unit based on bypass turbine and hydrogen energy storage according to claim 1, characterized in that: The gas-steam combined cycle unit comprises a waste heat boiler (1), a gas turbine (2), a compressor (3), a steam turbine high-pressure cylinder (4), a steam turbine intermediate-pressure cylinder (5), a first generator (6), a 3S clutch (7) and a steam turbine low-pressure cylinder (8); The bypass unit includes a synchronous generator (10), a permanent magnet generator (11), a fourth regulating valve (12), a fifth regulating valve (13), a sixth regulating valve (14), a variable speed centripetal turbine (15) and a variable speed axial turbine (16); Air enters the compressor (3) from the inlet L through the air filter (26) and is pressurized. Natural gas in the natural gas pressure regulating station (25) enters the end of the compressor (3). After the air and natural gas are mixed and burned in the compressor (3), the high-temperature flue gas enters the gas turbine (2) to perform work, and the exhaust gas enters the waste heat boiler (1). The condensate pump (29) is connected to the feed water inlet g of the waste heat boiler (1). After being heated by the waste heat boiler (1), the condensate is connected to the deaerator (17) from the outlet a. The feed water at the outlet of the deaerator (17) is divided into three streams, which respectively pass through the low-pressure feed water pump (18), the medium-pressure feed water pump (19) and the high-pressure feed water pump (20) and return to the waste heat boiler (1) from the inlets b, d and e of the waste heat boiler (1). After being heated, the high-pressure steam flows out from the outlet j, i and h of the waste heat boiler (1). Among them, the high-pressure steam flowing out from the outlet j enters the high-pressure cylinder (4) through the inlet n. The medium-pressure steam flowing out of i passes through the third regulating valve (28) and merges with the steam at the outlet m of the high-pressure cylinder (4) before entering the medium-pressure cylinder (5) from the inlet o. The steam flowing out of the medium-pressure cylinder (5) is divided into three streams. The first stream enters the low-pressure cylinder (8) from p, the second stream enters the variable speed centrifugal turbine (15) from s, passes through the outlet t of the variable speed centrifugal turbine (15) through the inlet u and enters the constant speed axial flow turbine (16). The constant speed axial flow turbine (16) is connected to the inlet w of the condenser (9) through the outlet v. The third stream merges with the steam flowing out of the outlet h of the waste heat boiler (1) through the second regulating valve (27) and enters the independent starting system. After flowing out of the low-pressure cylinder (8), the steam is discharged through the outlet q of the condenser (9), and after being pressurized by the condensate pump (29), it enters the waste heat boiler (1) through g to carry out the next cycle; the steam at the outlet c of the waste heat boiler (1) is used as the feed water heating steam for the deaerator (17), the variable speed centripetal turbine (15) is connected to the permanent magnet generator (11); and the fixed speed axial flow turbine (16) is connected to the synchronous generator (10).

3. The ultra-wide load combined cycle unit based on bypass turbine and hydrogen energy storage according to claim 2, characterized in that: The gas-steam combined cycle unit comprises a waste heat boiler (1), a gas turbine (2), a compressor (3), a steam turbine high-pressure cylinder (4), a steam turbine intermediate-pressure cylinder (5), a first generator (6), a 3S clutch (7) and a steam turbine low-pressure cylinder (8); The bypass unit includes a synchronous generator (10), a fourth regulating valve (12), a sixth regulating valve (14), and a variable speed axial flow turbine (16); Air enters the compressor (3) inlet L through the air filter (26) and is pressurized. Natural gas in the natural gas pressure regulating station (25) enters the compressor (3) from the end. After the air and natural gas are mixed and burned in the compressor (3), the high-temperature flue gas enters the gas turbine (2) to perform work, and the exhaust gas enters the waste heat boiler (1). The condensate pump (29) is connected to the feed water inlet g of the waste heat boiler (1). After being heated by the waste heat boiler (1), the condensate is connected to the deaerator (17) from the outlet a. The feed water at the outlet of the deaerator (17) is divided into three streams, which respectively pass through the low-pressure feed water pump (18), the medium-pressure feed water pump (19) and the high-pressure feed water pump (20), and return to the waste heat boiler (1) from the waste heat boiler (1) inlets b, d, and e respectively. After being heated, the high-pressure steam flows out from the waste heat boiler (1) outlets j, i, and h respectively. Among them, the high-pressure steam flowing out from the outlet j enters the high-pressure cylinder (4) through the inlet n. The medium-pressure steam flowing out from i passes through the third regulating valve (28) and merges with the steam from the outlet m of the high-pressure cylinder (4) before entering the medium-pressure cylinder (5) from the inlet o. The steam flowing out of the medium-pressure cylinder (5) is divided into three streams. The first stream enters the low-pressure cylinder (8) from p, the second stream enters the variable-speed axial flow turbine (16) from u, and enters the condenser (9) from the outlet v of the variable-speed axial flow turbine (16) through the inlet w. The third stream merges with the steam flowing out of the outlet h of the waste heat boiler (1) through the second regulating valve (27) and enters the independent starting system. After flowing out of the low-pressure cylinder (8), it is discharged through the outlet q of the condenser (9), and after being pressurized by the condensate pump (29), it enters the waste heat boiler (1) through g to carry out the next cycle; the steam at the outlet c of the waste heat boiler (1) is used as the feed water heating steam for the deaerator (17), and the fixed-speed axial flow turbine (16) is connected to the synchronous generator (10).

4. The ultra-wide load combined cycle unit based on bypass turbine and hydrogen energy storage according to claim 2, characterized in that: The independent startup system comprises a desalted water source (30), a startup boiler (32), a plant auxiliary steam header (33), a water electrolysis hydrogen production module (35), a hydrogen storage tank (36) and an oxygen storage tank (37). The desalted water in the desalted water source (30) is connected from the outlet y to the inlet aa of the startup boiler (32) through the eighth regulating valve (31), and enters the startup boiler (32) from aa, and is connected from the outlet ab to the inlet ad of the plant auxiliary steam header (33). The steam flowing out of the outlet h of the waste heat boiler (1) and the steam flowing out of the medium pressure cylinder (5) are combined and then pass through the seventh regulating valve (34) to enter the plant auxiliary steam header (33) from the inlet ae. The steam flows from the plant auxiliary steam header The outlet af of (33) is connected to each steam-using equipment. Part of the steam at the outlet af is mixed with the steam flowing through the fifth regulating valve (13) through the inlet x and the sixth regulating valve (14) and then enters the inlet s of the centripetal turbine (15). The output end of the water electrolysis hydrogen production module (35) is connected to the hydrogen storage tank (36) and the oxygen storage tank (37) respectively. The output ends of the hydrogen storage tank (36) and the oxygen storage tank (37) are merged through the pipeline and enter the start-up boiler (32) from the inlet ag. The outlet k of the natural gas pressure regulating station (25) is connected to the inlet of the start-up boiler (32) through the first regulating valve (21). The outlet ac of the start-up boiler (32) is connected to the inlet f of the waste heat boiler (1).

5. The ultra-wide load combined cycle unit based on bypass turbine and hydrogen energy storage according to claim 3, characterized in that: The independent startup system comprises a desalted water source (30), a startup boiler (32), a plant auxiliary steam header (33), a water electrolysis hydrogen production module (35), a hydrogen storage tank (36) and an oxygen storage tank (37). The desalted water in the desalted water source (30) is connected from the outlet y to the inlet aa of the startup boiler (32) through the eighth regulating valve (31), and enters the startup boiler (32) from aa, and is connected from the outlet ab to the inlet ad of the plant auxiliary steam header (33). The steam flowing out of the outlet h of the waste heat boiler (1) and the steam flowing out of the medium pressure cylinder (5) are combined and then pass through the seventh regulating valve (34) to enter the plant auxiliary steam header (33) from the inlet ae. The steam flows from the plant auxiliary steam header The outlet af (33) is connected to each steam-using equipment. Part of the steam at the outlet af is mixed with the steam discharged from the constant-speed axial flow turbine (16) through the inlet x and the sixth regulating valve (14) and then enters the condenser (9) through the inlet w. The output end of the water electrolysis hydrogen production module (35) is respectively connected to the hydrogen storage tank (36) and the oxygen storage tank (37). The output ends of the hydrogen storage tank (36) and the oxygen storage tank (37) are merged through the pipeline and enter the start-up boiler (32) from the inlet ag. The outlet k of the natural gas pressure regulating station (25) is connected to the inlet of the start-up boiler (32) through the first regulating valve (21). The outlet ac of the start-up boiler (32) is connected to the inlet f of the waste heat boiler (1).

6. The ultra-wide load combined cycle unit based on bypass turbine and hydrogen energy storage according to claim 3, characterized in that: The independent startup system comprises a desalted water source (30), a startup boiler (32) and a plant auxiliary steam header (33). The desalted water in the desalted water source (30) enters the startup boiler (32) from the outlet aa through the eighth regulating valve (31), and is connected to the inlet af of the plant auxiliary steam header (33) from the outlet ad. The steam flowing out of the outlet h of the waste heat boiler (1) is combined and enters the inlet ag through the seventh regulating valve (34) and enters the plant auxiliary steam header (33). The steam is connected to various steam-using equipment from the outlet ah of the plant auxiliary steam header (33). Part of the steam at the outlet ah is mixed with the steam discharged from the constant speed axial flow turbine (16) through the inlet x and the sixth regulating valve (14) and then enters the condenser (9) through the inlet w. The outlet k of the natural gas pressure regulating station (25) is connected to the inlet of the startup boiler (32) through the first regulating valve (21). The outlet ae of the startup boiler (32) is connected to the inlet f of the waste heat boiler (1).

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