A high-efficiency flexible adjustment supercritical carbon dioxide reheat power generation system and method

Abstract

Embodiments of the present application provide a high-efficiency flexible adjustment supercritical carbon dioxide reheating power generation system and method, the power generation system comprising a first shaft system, a second shaft system, a third shaft system, a regenerator assembly, a boiler and a precooler; the first shaft system comprising coaxially arranged high-pressure turbine part, low-pressure turbine part and power generation part; the high-pressure turbine part and the power generation part are arranged at opposite ends of the low-pressure turbine part through a shaft; the second shaft system comprising coaxially arranged main compressor variable-speed driving turbine part and main compressor part; the third shaft system comprising coaxially arranged re-compressor variable-speed driving turbine part and re-compressor part; the main compressor part outlet communicates with the cold side inlet of the regenerator assembly; the cold side outlet of the regenerator assembly communicates with the gas inlet of the boiler; the high-pressure turbine part inlet and the main compressor variable-speed driving turbine part inlet are connected in parallel through a pipeline and communicate with the main gas outlet of the boiler; the low-pressure turbine part inlet and the re-compressor variable-speed driving turbine part inlet are connected in parallel through a pipeline and communicate with the reheating outlet of the boiler.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application belong to the technical field of power generation, and particularly relate to a high-efficiency flexible adjustment supercritical carbon dioxide reheating power generation system and method. BACKGROUND

[0002] The supercritical carbon dioxide power cycle has advantages of high efficiency, flexibility, compactness, etc., and has broad application prospects in fields of coal-fired power generation, nuclear power, solar thermal power generation, waste heat power generation, etc.

[0003] In recent years, the technology has developed rapidly from theoretical research to experimental verification stage, which marks that the technology is closer to industrial application. At present, the recompression supercritical carbon dioxide cycle configuration is the most potential system configuration, which has the characteristics of high efficiency compared with other configurations. In addition, for example, in the field of coal-fired power generation, the reheating mode is generally used to further improve the thermal efficiency of the system. Therefore, the system has more rotating equipment, including four rotating equipment of high-pressure turbine, low-pressure turbine, main compressor and recompression compressor, and the arrangement mode of the rotating equipment shaft system has a great influence on the system efficiency and system adjustment operation. Generally, in order to facilitate the adjustment of the compressor, the main compressor and the recompression compressor are respectively driven by the motor, and the motor is generally connected with the compressor through the frequency converter and the speed increaser, and the variable speed adjustment of the compressor is performed, so that the compressor can also work in the high efficiency area when the variable working condition is adjusted.

[0004] However, this way has more shaft energy transmission links, and the energy loss is large, which significantly reduces the system efficiency. Therefore, in order to reduce the shaft transmission loss, all rotating equipment can be arranged coaxially, that is, the high-pressure turbine, the low-pressure turbine, the main compressor and the recompression compressor are arranged on the same shaft, and the main compressor and the recompression compressor are directly driven by the high-pressure turbine and the low-pressure turbine to operate, thereby reducing unnecessary intermediate transmission equipment and energy conversion links. However, in order to meet the requirement of constant frequency of the power grid, the turbine driving the generator needs to maintain constant speed operation all the time. Since the turbine and the compressor are coaxial, the main compressor and the recompression compressor also need to maintain constant speed operation, which reduces the flexibility of the compressor adjustment, and cannot meet the requirements of variable working condition operation and load change of the system. The compressor can only be adjusted by throttling, and cannot work in the high efficiency area by variable speed, which reduces the efficiency of the compressor and further reduces the performance of the system. Therefore, the recompression and reheating supercritical carbon dioxide cycle power generation system needs to develop a new type of shaft arrangement mode and system to meet the requirements of high efficiency and flexible adjustment. SUMMARY

[0005] Embodiments of the present application aim to at least solve one of the technical problems existing in the prior art, and provide a high-efficiency flexible adjustment supercritical carbon dioxide reheating power generation system and method.

[0006] The first aspect of the embodiment of the present application provides a high-efficiency flexible adjustment supercritical carbon dioxide reheating power generation system, the power generation system comprising a first shaft system, a second shaft system, a third shaft system, a regenerator assembly, a boiler and a precooler;

[0007] The first shaft system comprises a high-pressure turbine part, a low-pressure turbine part and a power generation part arranged coaxially; the high-pressure turbine part and the power generation part are arranged at opposite ends of the low-pressure turbine part through shafts; the second shaft system comprises a main compressor variable-speed driving turbine part and a main compressor part arranged coaxially; the third shaft system comprises a re-compressor variable-speed driving turbine part and a re-compressor part arranged coaxially;

[0008] The main compressor part outlet is communicated with the cold side inlet of the regenerator assembly; the cold side outlet of the regenerator assembly is communicated with the gas inlet of the boiler;

[0009] The high-pressure turbine part inlet and the main compressor variable-speed driving turbine part inlet are connected in parallel through pipelines and communicated with the main gas outlet of the boiler; the high-pressure turbine part outlet and the main compressor variable-speed driving turbine part outlet are both communicated with the reheating inlet of the boiler;

[0010] The low-pressure turbine part inlet and the re-compressor variable-speed driving turbine part inlet are connected in parallel through pipelines and communicated with the reheating outlet of the boiler; the low-pressure turbine part outlet and the re-compressor variable-speed driving turbine part outlet are both communicated with the hot side inlet of the regenerator assembly;

[0011] The re-compressor part inlet and the precooler inlet are respectively communicated with the hot side outlet of the regenerator assembly;

[0012] The precooler outlet is communicated with the main compressor part inlet; the re-compressor part outlet is communicated with the cold side outlet of the regenerator assembly.

[0013] Optionally, the high-pressure turbine part and the low-pressure turbine part are arranged in head-to-head.

[0014] Optionally, the high-pressure turbine part comprises a main gas regulating valve and a high-pressure turbine; the main gas regulating valve is arranged at the pipeline at the high-pressure turbine inlet; the high-pressure turbine is arranged coaxially with the low-pressure turbine part and the power generation part.

[0015] Optionally, the low-pressure turbine part comprises a reheating gas regulating valve and a low-pressure turbine; the reheating gas regulating valve is arranged at the pipeline at the low-pressure turbine inlet; the low-pressure turbine is arranged coaxially with the high-pressure turbine part and the power generation part.

[0016] Optionally, the main compressor variable speed drive turbine part comprises a main flow regulating valve and a main compressor drive turbine; the main flow regulating valve is arranged on the pipeline at the inlet of the main compressor drive turbine; and the main compressor drive turbine is coaxially arranged with the main compressor part.

[0017] Optionally, the re-compressor variable speed drive turbine part comprises a reheat flow regulating valve and a re-compressor drive turbine; the reheat flow regulating valve is arranged on the pipeline at the inlet of the re-compressor drive turbine; and the re-compressor drive turbine is coaxially arranged with the re-compressor part.

[0018] Optionally, the re-compressor part comprises a re-compressor, a re-compressor clutch and a re-compressor starting motor arranged coaxially in sequence.

[0019] The main compressor part comprises a main compressor, a main compressor clutch and a main compressor starting motor arranged coaxially in sequence.

[0020] Optionally, the regenerator assembly comprises a low-temperature regenerator and a high-temperature regenerator.

[0021] The cold side inlet of the low-temperature regenerator is in communication with the outlet of the main compressor part; and the cold side outlet of the low-temperature regenerator is in communication with the cold side inlet of the high-temperature regenerator.

[0022] The hot side inlet of the low-temperature regenerator is in communication with the hot side outlet of the high-temperature regenerator; and the hot side outlet of the low-temperature regenerator is in communication with the inlet of the pre-cooler and the inlet of the re-compressor part, respectively.

[0023] The cold side outlet of the high-temperature regenerator is in communication with the inlet of the boiler gas supply; the hot side inlet of the high-temperature regenerator is in communication with the outlet of the low-pressure turbine part and the outlet of the re-compressor variable speed drive turbine part, respectively; and the hot side outlet of the high-temperature regenerator is in communication with the hot side inlet of the low-temperature regenerator.

[0024] Optionally, the speed regulation range of the main compressor variable speed drive turbine part and the main compressor part is 20% to 110%.

[0025] The speed regulation range of the re-compressor variable speed drive turbine part and the re-compressor part is 20% to 110%.

[0026] In a second aspect of the embodiments of the present application, a high-efficiency flexible adjustment supercritical carbon dioxide reheat power generation method is provided, which is realized according to the system described above and comprises the following steps:

[0027] The main compressor starting motor and the re-compressor starting motor are used to drive the main compressor and the re-compressor to operate, respectively.

[0028] When the output load of the main compressor driving turbine and the re-compressor driving turbine reaches the rated working load of driving the main compressor and the re-compressor, the main compressor starting motor and the re-compressor starting motor are disconnected through the main compressor clutch and the re-compressor clutch;

[0029] The main flow regulating valve and the reheat flow regulating valve are used to adjust the flow of the main compressor driving turbine and the re-compressor driving turbine respectively, so as to realize the load matching and speed control of the main compressor and the re-compressor.

[0030] The beneficial effects of the embodiments of the present application include:

[0031] In the present application, 1, the high-pressure turbine part and the main compressor variable-speed driving turbine part are connected in parallel through a pipeline, wherein the high-pressure turbine part is coaxially connected with the power generation part, and the main compressor variable-speed driving turbine part is coaxially connected with the main compressor part, thereby realizing the parallel connection and shaft separation design of the high-pressure turbine part and the main compressor variable-speed driving turbine part. Further, the low-pressure turbine part and the re-compressor variable-speed driving turbine part are connected in parallel through a pipeline, wherein the low-pressure turbine part is coaxially connected with the power generation part, and the re-compressor variable-speed driving turbine part is coaxially connected with the re-compressor part, thereby realizing the parallel connection and shaft separation design of the low-pressure turbine part and the re-compressor variable-speed driving turbine part. In summary, the present application realizes complete decoupling of turbine power generation and driving through parallel and shaft separation arrangement of turbines, thereby realizing efficient and flexible adjustment of compressors and facilitating efficient and flexible operation of the system.

[0032] 2, The present application utilizes the main compressor variable-speed driving turbine part and the re-compressor variable-speed driving turbine part to realize variable-speed adjustment of the main compressor part and the re-compressor part respectively, which can make the compressor operate at a relatively high efficiency, thereby improving the system power generation efficiency.

[0033] 3, The main compressor part and the re-compressor part of the present application are directly driven by the corresponding main compressor variable-speed driving turbine part and the re-compressor variable-speed driving turbine part, which reduces energy transmission loss and is conducive to improving the system power generation efficiency.

[0034] 4, The high-pressure turbine part and the low-pressure turbine part of the present application are coaxially arranged and only drive the power generation part, which can realize constant-speed power generation, simplify shaft arrangement, reduce the number of generators, and is conducive to power grid scheduling. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 The structure diagram of a high-efficiency flexible adjustment supercritical carbon dioxide reheat power generation system according to an embodiment of the present application.

[0036] In the diagram, 1. Main compressor; 2. Low-temperature regenerator; 3. High-temperature regenerator; 4. Boiler; 5. High-pressure turbine; 6. Low-pressure turbine; 7. Precooler; 8. Recompressor; 9. Main compressor drive turbine; 10. Recompressor drive turbine; 11. Generator; 12. Main compressor starter motor; 13. Recompressor starter motor; 14. Main compressor clutch; 15. Recompressor clutch; 16. Main gas regulating valve; 17. Reheat gas regulating valve; 18. Main flow regulating valve; 19. Reheat flow regulating valve. Detailed Implementation

[0037] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] The embodiments of this application will be further described in detail below with reference to the accompanying drawings and examples. The detailed descriptions and accompanying drawings of the following embodiments are used to exemplarily illustrate the principles of this application, but should not be used to limit the scope of this application; that is, this application is not limited to the described embodiments. In the description of this application, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," etc., indicating orientation or positional relationships are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. "Vertical" is not strictly vertical, but within the allowable error range. "Parallel" is not strictly parallel, but within the allowable error range.

[0039] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application depending on the specific circumstances.

[0040] like Figure 1 As shown, a highly efficient and flexible supercritical carbon dioxide reheat power generation system is disclosed. The power generation system includes a first shaft system, a second shaft system, a third shaft system, a regenerator assembly, a boiler 4, and a precooler 7.

[0041] The first shaft system comprises a high-pressure turbine part, a low-pressure turbine part and a power generation part arranged coaxially, the high-pressure turbine part and the power generation part are arranged at opposite ends of the low-pressure turbine part through a shaft, the second shaft system comprises a main compressor variable-speed driving turbine part and a main compressor part arranged coaxially, and the third shaft system comprises a re-compressor variable-speed driving turbine part and a re-compressor part arranged coaxially.

[0042] The outlet of the main compressor part is communicated with the cold side inlet of the regenerator assembly, and the outlet of the cold side of the regenerator assembly is communicated with the gas inlet of the boiler 4. The inlet of the high-pressure turbine part and the inlet of the main compressor variable-speed driving turbine part are connected in parallel through a pipeline and communicated with the main gas outlet of the boiler 4, and the outlet of the high-pressure turbine part and the outlet of the main compressor variable-speed driving turbine part are both communicated with the reheating inlet of the boiler 4.

[0043] The inlet of the low-pressure turbine part and the inlet of the re-compressor variable-speed driving turbine part are connected in parallel through a pipeline and communicated with the reheating outlet of the boiler 4, and the outlet of the low-pressure turbine part and the outlet of the re-compressor variable-speed driving turbine part are both communicated with the hot side inlet of the regenerator assembly. The inlet of the re-compressor part and the inlet of the pre-cooler 7 are both communicated with the hot side outlet of the regenerator assembly. The outlet of the pre-cooler 7 is communicated with the inlet of the main compressor part, and the outlet of the re-compressor part is communicated with the outlet of the cold side of the regenerator assembly. It can be understood that the circulating working medium of the power generation system is supercritical carbon dioxide.

[0044] In the application, 1, the high-pressure turbine part and the main compressor variable-speed driving turbine part are connected in parallel through a pipeline, wherein the high-pressure turbine part is coaxially connected with the power generation part, and the main compressor variable-speed driving turbine part is coaxially connected with the main compressor part, so that the parallel connection and shaft separation design of the high-pressure turbine part and the main compressor variable-speed driving turbine part are realized. Further, the low-pressure turbine part and the re-compressor variable-speed driving turbine part are connected in parallel through a pipeline, wherein the low-pressure turbine part is coaxially connected with the power generation part, and the re-compressor variable-speed driving turbine part is coaxially connected with the re-compressor part, so that the parallel connection and shaft separation design of the low-pressure turbine part and the re-compressor variable-speed driving turbine part are realized. In summary, the turbine parallel shaft arrangement is realized, the decoupling of turbine power generation and driving is realized, the compressor is flexibly adjusted with high efficiency, and the system is flexibly and efficiently operated.

[0045] 2, the main compressor variable-speed driving turbine part and the re-compressor variable-speed driving turbine part can respectively realize the variable-speed adjustment of the main compressor part and the re-compressor part, so that the compressor can be operated at a high efficiency, and the system power generation efficiency is improved.

[0046] 3, the main compressor part and the re-compressor part are directly driven by the corresponding main compressor variable-speed driving turbine part and the re-compressor variable-speed driving turbine part, so that the energy transmission loss is reduced, and the system power generation efficiency is improved.

[0047] 4、The high-pressure turbine part and the low-pressure turbine part are coaxially arranged, and only drive the power generation part, so that fixed-speed power generation can be realized, the shafting arrangement is simplified, the number of generators 11 is reduced, and grid scheduling is facilitated.

[0048] In some embodiments, the high-pressure turbine part and the low-pressure turbine part are arranged in a head-to-head manner. Arranging the high-pressure turbine part and the low-pressure turbine part in a head-to-head manner can enable the high-pressure turbine 5 and the low-pressure turbine 6 to intake air in the reverse direction along the shaft direction, so as to balance the axial thrust.

[0049] In some embodiments, the high-pressure turbine part comprises a main gas regulating valve 16 and the high-pressure turbine 5, the main gas regulating valve 16 is arranged on the pipeline at the inlet of the high-pressure turbine 5, and the high-pressure turbine 5 is coaxially arranged with the low-pressure turbine part and the power generation part.

[0050] In some embodiments, the low-pressure turbine part comprises a reheated gas regulating valve 17 and the low-pressure turbine 6, the reheated gas regulating valve 17 is arranged on the pipeline at the inlet of the low-pressure turbine 6, and the low-pressure turbine 6 is coaxially arranged with the high-pressure turbine part and the power generation part.

[0051] In some embodiments, the power generation part comprises a generator 11. Specifically, the high-pressure turbine 5, the low-pressure turbine 6 and the generator 11 are coaxially arranged.

[0052] In some embodiments, the main compressor variable-speed driving turbine part comprises a main flow regulating valve 18 and a main compressor driving turbine 9, the main flow regulating valve 18 is arranged on the pipeline at the inlet of the main compressor driving turbine 9, and the main compressor driving turbine 9 is coaxially arranged with the main compressor part.

[0053] In some embodiments, the re-compressor variable-speed driving turbine part comprises a reheated flow regulating valve 19 and a re-compressor driving turbine 10, the reheated flow regulating valve 19 is arranged on the pipeline at the inlet of the re-compressor driving turbine 10, and the re-compressor driving turbine 10 is coaxially arranged with the re-compressor part.

[0054] In some embodiments, the re-compressor part comprises a re-compressor 8, a re-compressor clutch 15 and a re-compressor starting motor 13 which are coaxially arranged in sequence. The main compressor part comprises a main compressor 1, a main compressor clutch 14 and a main compressor starting motor 12 which are coaxially arranged in sequence.

[0055] Specifically, the main compressor driving turbine 9 is coaxially arranged with the main compressor 1, and the re-compressor driving turbine 10 is coaxially arranged with the re-compressor 8.

[0056] In some embodiments, the regenerator assembly comprises a low-temperature regenerator 2 and a high-temperature regenerator 3. The cold side inlet of the low-temperature regenerator 2 is in communication with the outlet of the main compressor part, and the cold side outlet of the low-temperature regenerator 2 is in communication with the cold side inlet of the high-temperature regenerator 3. The hot side inlet of the low-temperature regenerator 2 is in communication with the hot side outlet of the high-temperature regenerator 3, wherein the hot side outlet of the low-temperature regenerator 2 is in communication with the inlet of the pre-cooler 7 and the inlet of the re-compressor part, respectively.

[0057] The cold side outlet of the high temperature recuperator 3 is communicated with the gas inlet of the boiler 4, the hot side inlets of the high temperature recuperator 3 are respectively communicated with the outlet of the low pressure turbine part and the outlet of the variable speed driving turbine part of the re-compressor, and the hot side outlet of the high temperature recuperator 3 is communicated with the hot side inlet of the low temperature recuperator 2. Specifically, the hot side inlets of the high temperature recuperator 3 are respectively communicated with the outlet of the low pressure turbine 6 and the outlet of the driving turbine 10 of the re-compressor.

[0058] In some embodiments, the speed regulation range of the variable speed driving turbine part of the main compressor and the main compressor part is 20% to 110%, and the speed regulation range of the variable speed driving turbine part of the re-compressor and the re-compressor part is 20% to 110%.

[0059] Specifically, the speed regulation range of the driving turbine 9 of the main compressor and the main compressor 1 is 20% to 110%.

[0060] The speed regulation range of the driving turbine 10 of the re-compressor and the re-compressor 8 is 20% to 110%.

[0061] One specific example provided by the present application comprises:

[0062] The present application provides a high-efficiency and flexible adjustment supercritical carbon dioxide reheat power generation system, which comprises a first shaft system, a second shaft system and a third shaft system. The first shaft system comprises a high pressure turbine 5, a low pressure turbine 6 and a generator 11 arranged coaxially, and the high pressure turbine 5 and the generator 11 are connected to the low pressure turbine 6 through shafts on both sides of the low pressure turbine 6 respectively.

[0063] The second shaft system comprises a main compressor driving turbine 9, a main compressor 1, a main compressor clutch 14 and a main compressor starting motor 12 arranged coaxially. The main compressor driving turbine 9 and the main compressor starting motor 12 are connected to the main compressor 1 through shafts on both sides of the main compressor 1 respectively, and the main compressor 1 and the main compressor starting motor 12 are connected through the main compressor clutch 14 between the shafts.

[0064] The third shaft system comprises a re-compressor driving turbine 10, a re-compressor 8, a re-compressor clutch 15 and a re-compressor starting motor 13 arranged coaxially. The re-compressor driving turbine 10 and the re-compressor starting motor 13 are connected to the re-compressor 8 through shafts on both sides of the re-compressor 8 respectively, and the re-compressor 8 and the re-compressor starting motor 13 are connected through the re-compressor clutch 15 between the shafts.

[0065] The power generation system further comprises a low temperature recuperator 2, a high temperature recuperator 3, a boiler 4 and a pre-cooler 7.

[0066] Specifically, the main compressor 1 outlet is connected with the low-temperature regenerator 2 cold side inlet, the low-temperature regenerator 2 cold side outlet is connected with the high-temperature regenerator 3 cold side inlet, and the high-temperature regenerator 3 cold side outlet is connected with the boiler 4 gas inlet. The boiler 4 main gas outlet is divided into two, one is connected with the high-pressure turbine 5 inlet through the main gas regulating valve 16, and the other is connected with the main compressor drive turbine 9 inlet through the main flow regulating valve 18. The high-pressure turbine 5 outlet and the main compressor drive turbine 9 outlet are connected with the boiler 4 reheat inlet. The boiler 4 reheat outlet is divided into two, one is connected with the low-pressure turbine 6 inlet through the reheat gas regulating valve 17, and the other is connected with the re-compressor drive turbine 10 inlet through the reheat flow regulating valve 19. The low-pressure turbine 6 outlet and the re-compressor drive turbine 10 outlet are connected with the high-temperature regenerator 3 hot side inlet, and the high-temperature regenerator 3 hot side outlet is connected with the low-temperature regenerator 2 hot side inlet. The low-temperature regenerator 2 hot side outlet is divided into two, one is connected with the pre-cooler 7 inlet, and the pre-cooler 7 outlet is connected with the main compressor 1 inlet. The other is connected with the re-compressor 8 inlet, and the re-compressor 8 outlet is connected with the low-temperature regenerator 2 cold side outlet.

[0067] In a second aspect of the embodiments of the present application, a high-efficiency flexible adjustment supercritical carbon dioxide reheat power generation method is provided, which is realized according to the power generation system described above, and comprises the following steps.

[0068] In S101, the main compressor starting motor 12 and the re-compressor starting motor 13 are used to drive the main compressor 1 and the re-compressor 8 to run, respectively.

[0069] In S102, when the output load of the main compressor drive turbine 9 and the re-compressor drive turbine 10 reaches the rated working load of driving the main compressor 1 and the re-compressor 8, the main compressor starting motor 12 and the re-compressor starting motor 13 are disconnected by the main compressor clutch 14 and the re-compressor clutch 15, respectively.

[0070] In S103, the main flow regulating valve 18 and the reheat flow regulating valve 19 are used to adjust the flow of the main compressor drive turbine 9 and the re-compressor drive turbine 10, respectively, so as to realize the load matching and speed control of the main compressor 1 and the re-compressor 8.

[0071] In a specific example of the present application, the following steps are included:

[0072] In the high-efficiency flexible adjustment supercritical carbon dioxide reheat power generation method of the present application, in the starting stage, the main compressor 1 and the re-compressor 8 are driven to run by the main compressor starting motor 12 and the re-compressor starting motor 13, respectively.

[0073] When the output load of the main compressor driving turbine 9 and the re-compressor driving turbine 10 can completely drive the main compressor 1 and the re-compressor 8, the main compressor starting motor 12 and the re-compressor starting motor 13 are respectively disconnected through the main compressor clutch 14 and the re-compressor clutch 15.

[0074] The main compressor driving turbine 9 and the re-compressor driving turbine 10 respectively adjust the flow through the main flow regulating valve 18 and the reheat flow regulating valve 19, and realize the load matching and speed control of the main compressor 1 and the re-compressor 8 respectively.

[0075] Further, when the system load changes, the main compressor driving turbine 9 adjusts the intake flow through the main flow regulating valve 18, and then adjusts the output load, so as to adjust the speed of the main compressor 1, and then adjust the flow of the main compressor 1.

[0076] The re-compressor driving turbine 10 adjusts the intake flow through the reheat flow regulating valve 19, and then adjusts the output load, so as to adjust the speed of the re-compressor 8, and then adjust the flow of the re-compressor 8.

[0077] In the application, the compressor flow is adjusted by the speed, which can avoid the sharp deterioration of the compressor efficiency, so that the compressor can operate at a high efficiency, and the energy saving and efficiency improvement effect is achieved.

[0078] The application has the following advantages:

[0079] 1. The turbine of the application includes parallel power generation turbines (high-pressure turbine 5 and low-pressure turbine 6) and driving turbines (main compressor driving turbine 9 and re-compressor driving turbine 10), which operate independently and do not affect each other, realize complete decoupling of power generation and driving, and enhance the system regulation flexibility.

[0080] 2. The application can realize the variable speed driving of the compressor by the turbine (main compressor driving turbine 9 and re-compressor driving turbine 10), and then realize the variable speed flow regulation of the compressor, so that the compressor can operate at a high efficiency, and the system power generation efficiency is improved.

[0081] 3. The high-pressure turbine 5 and the low-pressure turbine 6 of the application are coaxially arranged and only drive the generator 11, which can realize constant speed power generation, simplify the shaft arrangement, reduce the number of generators 11, and is beneficial to the power grid scheduling.

[0082] 4. The high-pressure turbine 5 and the low-pressure turbine 6 of the application are arranged in opposite directions along the shaft, which is beneficial to balance the axial thrust and reduce the design difficulty of the bearing system.

[0083] It is understood that the above embodiments are only exemplary for illustrating the principles of the present application, and the present application is not limited thereto. Various modifications and improvements can be made by those skilled in the art without departing from the spirit and scope of the present application, and these modifications and improvements are also considered as the protection scope of the present application.

Claims

1. A highly efficient flexible regulated supercritical carbon dioxide reheat power generation system, characterized by, The power generation system comprises a first shaft system, a second shaft system, a third shaft system, a regenerator assembly, a boiler and a precooler; The first shaft system comprises a high-pressure turbine part, a low-pressure turbine part and a power generation part arranged coaxially; the high-pressure turbine part and the power generation part are arranged at opposite ends of the low-pressure turbine part through shafts; the second shaft system comprises a main compressor variable-speed driving turbine part and a main compressor part arranged coaxially; the third shaft system comprises a re-compressor variable-speed driving turbine part and a re-compressor part arranged coaxially; The outlet of the main compressor part is communicated with the cold side inlet of the regenerator assembly; the cold side outlet of the regenerator assembly is communicated with the gas inlet of the boiler; The inlet of the high-pressure turbine part and the inlet of the main compressor variable-speed driving turbine part are connected in parallel through pipelines and communicated with the main gas outlet of the boiler; the outlet of the high-pressure turbine part and the outlet of the main compressor variable-speed driving turbine part are both communicated with the reheating inlet of the boiler; The inlet of the low-pressure turbine part and the inlet of the re-compressor variable-speed driving turbine part are connected in parallel through pipelines and communicated with the reheating outlet of the boiler; the outlet of the low-pressure turbine part and the outlet of the re-compressor variable-speed driving turbine part are both communicated with the hot side inlet of the regenerator assembly; The inlet of the re-compressor part and the inlet of the precooler are both communicated with the hot side outlet of the regenerator assembly; The outlet of the precooler is communicated with the inlet of the main compressor part; the outlet of the re-compressor part is communicated with the cold side outlet of the regenerator assembly; The re-compressor part comprises a re-compressor, a re-compressor clutch and a re-compressor starting motor arranged coaxially in sequence; The main compressor part comprises a main compressor, a main compressor clutch and a main compressor starting motor arranged coaxially in sequence.

2. The high-efficiency flexible-adjustment supercritical carbon dioxide reheat power generation system according to claim 1, characterized in that, The high-pressure turbine part and the low-pressure turbine part are arranged in head-to-head manner.

3. The high-efficiency flexible adjustment supercritical carbon dioxide reheat power generation system according to claim 1 or 2, characterized in that, The high-pressure turbine part comprises a main gas regulating valve and a high-pressure turbine; the main gas regulating valve is arranged at the pipeline at the inlet of the high-pressure turbine; the high-pressure turbine is arranged coaxially with the low-pressure turbine part and the power generation part.

4. The high-efficiency flexible adjustment supercritical carbon dioxide reheat power generation system according to claim 1 or 2, characterized in that, The low-pressure turbine part comprises a reheating gas regulating valve and a low-pressure turbine; the reheating gas regulating valve is arranged at the pipeline at the inlet of the low-pressure turbine; the low-pressure turbine is arranged coaxially with the high-pressure turbine part and the power generation part.

5. The high-efficiency flexible-adjusting supercritical carbon dioxide reheat power generation system according to claim 1 or 2, characterized in that, The main compressor variable-speed driving turbine part comprises a main flow regulating valve and a main compressor driving turbine; the main flow regulating valve is arranged at the pipeline at the inlet of the main compressor driving turbine; The main compressor driving turbine is arranged coaxially with the main compressor part.

6. The high-efficiency flexible-adjusting supercritical carbon dioxide reheat power generation system according to claim 1 or 2, characterized in that, The re-compressor variable-speed driving turbine part comprises a reheating flow regulating valve and a re-compressor driving turbine; the reheating flow regulating valve is arranged at the pipeline at the inlet of the re-compressor driving turbine; The re-compressor driving turbine is arranged coaxially with the re-compressor part.

7. The high-efficiency flexible-adjustment supercritical carbon dioxide reheat power generation system according to claim 1 or 2, characterized in that, The regenerator assembly comprises a low-temperature regenerator and a high-temperature regenerator; The cold side inlet of the low-temperature regenerator is communicated with the outlet of the main compressor part; the cold side outlet of the low-temperature regenerator is communicated with the cold side inlet of the high-temperature regenerator; The hot side inlet of the low-temperature regenerator is communicated with the hot side outlet of the high-temperature regenerator; the hot side outlet of the low-temperature regenerator is communicated with the inlet of the precooler and the inlet of the re-compressor part respectively. The high-temperature regenerator cold side outlet is communicated with the boiler gas inlet; the high-temperature regenerator hot side inlet is respectively communicated with the low-pressure turbine outlet and the variable speed driving turbine outlet of the re-compressor; and the high-temperature regenerator hot side outlet is communicated with the low-temperature regenerator hot side inlet.

8. The high-efficiency flexible adjustment supercritical carbon dioxide reheating power generation system according to claim 1 or 2, characterized in that, The speed regulation range of the variable speed driving turbine part and the main compressor part of the main compressor is 20% to 110%; The speed regulation range of the variable speed driving turbine part and the re-compressor part of the re-compressor is 20% to 110%.

9. A method for efficient and flexible supercritical carbon dioxide reheat power generation, said method being implemented according to the system of any one of claims 1-8, characterized in that, Comprise: The main compressor and the re-compressor are respectively driven by the main compressor starting motor and the re-compressor starting motor to operate; When the output load of the main compressor driving turbine and the re-compressor driving turbine reaches the rated working load of driving the main compressor and the re-compressor, the main compressor starting motor and the re-compressor starting motor are respectively disconnected by the main compressor clutch and the re-compressor clutch; The flow of the main compressor driving turbine and the re-compressor driving turbine is respectively adjusted by the main flow regulating valve and the reheat flow regulating valve to realize the load matching and speed control of the main compressor and the re-compressor.

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