Combined regulation type dynamic reconfiguration steam turbine generator unit and operation method

Abstract

The application provides a combined regulation type dynamic reconfiguration steam turbine generator unit and an operation method. In a low load working condition, with the decrease of a load rate, the total flow area of a low pressure area of the steam turbine unit is reduced by gradually cutting off low pressure regulating cylinders, and dynamic reconfiguration of the low pressure area is realized. In addition, in the low load working condition, a high pressure regulating stage group is connected in series before a high pressure cylinder, the high pressure regulating stage group and the high pressure cylinder are both put into operation, the flow area of the high pressure area is increased, the working link is increased, and a relatively high unit operation pressure is maintained through pressure transmission. Thus, the steam turbine unit realizes combined regulation type dynamic reconfiguration in the low load working condition, the regulation of the high pressure cylinder and the low pressure cylinder is independent and does not interfere with each other, the adaptability to the load working condition is improved, and the problem that the energy efficiency sharply decreases due to the decrease of the main reheat steam operation pressure in the steam turbine unit in the low load working condition is avoided.

Description

Technical Field

[0001] This invention belongs to the field of steam turbine power generation technology, and particularly relates to a combined regulation and dynamic reconfiguration steam turbine generator set and its operation method. Background Technology

[0002] With the large-scale grid connection of renewable energy sources such as photovoltaic and wind power, which exhibit random fluctuations, the basic power system, primarily composed of coal-fired power, is forced to fully participate in deep peak shaving. The design of coal-fired power units mainly considers operating efficiency under rated load conditions. However, during deep peak shaving, the power generation efficiency of these units deteriorates sharply under medium and low load conditions. Compared to rated load conditions, conventional coal-fired power units consume 30-40 g / kW·h more coal at 30% rated load. The direct cause is that under the "constant-sliding-constant" main steam pressure operation mode, the main steam pressure drops significantly under medium and low loads, directly leading to a decrease in the cycle efficiency of the thermal system and increasing the flow losses of the turbine itself.

[0003] Research and analysis have shown that under medium and low load conditions, the operating conditions of the high-pressure cylinder and the low-pressure cylinder deteriorate sharply, and the changes in the flow area requirements of the two cylinders are opposite. However, existing steam turbine units cannot undergo localized structural adaptive reconfiguration based on changes in flow area under medium and low load conditions, ultimately leading to a sharp deterioration in energy efficiency during deep peak shaving. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a combined regulating dynamic reconfiguration steam turbine generator set and its operation method, which is mainly used to solve the problem that the energy efficiency of the existing steam turbine generator set is drastically deteriorated when it is running under medium and low load conditions because its structural connection state cannot be adaptively reconfigured according to the changes in load conditions.

[0005] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0006] The first inventive point is to provide a combined adjustable dynamic reconfiguration steam turbine generator set, including a first rotating shaft, a low-pressure regulating stage group, and a low-pressure cylinder. The low-pressure cylinder and the low-pressure regulating stage group are arranged sequentially along the central axis of the first rotating shaft. The low-pressure regulating stage group includes at least one low-pressure regulating cylinder whose exhaust steam can be selectively connected to the condenser. A plurality of the low-pressure regulating cylinders are connected in series with the low-pressure cylinder. The exhaust steam of the low-pressure cylinder can be selectively connected to the condenser. The low-pressure regulating cylinder and the low-pressure cylinder form a low-pressure multi-stage reconfiguration cylinder group. The low-pressure multi-stage reconfiguration cylinder group is configured to disconnect the low-pressure regulating cylinders step by step from back to front along the steam flow direction when the load rate is lower than the set reconfiguration load.

[0007] The second inventive point is to provide a combined adjustable dynamic reconfiguration steam turbine generator set, including a first shaft, a second shaft, a low-pressure regulating stage group, and a low-pressure cylinder. The low-pressure cylinder is arranged on the first shaft, and the low-pressure regulating stage group is arranged on the second shaft. The low-pressure regulating stage group and the low-pressure cylinder are connected in parallel. The low-pressure regulating stage group includes at least one low-pressure regulating cylinder whose exhaust steam can be selectively connected to the condenser. Multiple low-pressure regulating cylinders are connected in series. The low-pressure regulating stage group is configured to replace the low-pressure cylinders in parallel when the load rate is lower than the set reconfiguration load, and the low-pressure regulating cylinders can be disconnected step by step from back to front along the steam flow direction.

[0008] In some embodiments, the system includes a boiler, a high-pressure cylinder, an intermediate-pressure cylinder, and a high-pressure regulating stage. The main steam outlet of the boiler is connected to the steam inlet of the high-pressure cylinder via a main steam pipeline. A main steam valve is provided on the main steam pipeline. The exhaust outlet of the high-pressure cylinder is connected to the reheat steam inlet of the boiler via a cold reheat steam pipeline. The reheat steam outlet of the boiler is connected to the steam inlet of the intermediate-pressure cylinder via a reheat steam pipeline. The steam outlet of the intermediate-pressure cylinder is connected to the steam inlet of the low-pressure cylinder. The high-pressure cylinder, intermediate-pressure cylinder, and low-pressure cylinder are arranged sequentially along the central axis of the first rotating shaft. A first valve is provided between the main steam valve and the high-pressure cylinder. The high-pressure regulating stage is connected in parallel with the first valve. The high-pressure regulating stage includes at least one high-pressure pre-stage that can be selectively connected to the steam network. Multiple high-pressure pre-stages are connected in series or in parallel. The exhaust of the high-pressure regulating stage can be selectively connected to the cold reheat steam pipeline.

[0009] In some embodiments, the high-pressure regulating stage is arranged on a first rotating shaft, and the high-pressure regulating stage, high-pressure cylinder, medium-pressure cylinder, low-pressure regulating stage and low-pressure cylinder are arranged sequentially on the first rotating shaft.

[0010] In some embodiments, the high-pressure regulating stage is arranged on the second rotating shaft, and the high-pressure regulating stage and the low-pressure regulating stage are arranged sequentially on the second rotating shaft, while the high-pressure cylinder, the medium-pressure cylinder and the low-pressure cylinder are arranged sequentially on the first rotating shaft.

[0011] In some embodiments, the connection point between the high-pressure cylinder exhaust and the cold reheat steam pipeline is a first cold reheat connection point, and the connection point between the high-pressure regulating stage exhaust and the cold reheat steam pipeline is a second cold reheat connection point. The first cold reheat connection point, the second cold reheat connection point, and the boiler can be selectively connected.

[0012] In some embodiments, a regenerative system is further included, the regenerative system comprising a first high-pressure heater and a second high-pressure heater, the conventional second extraction port of the high-pressure cylinder being connected to the second high-pressure heater pipeline via a first regenerative valve, the conventional first extraction port of the high-pressure cylinder being connected to the first high-pressure heater pipeline via a second regenerative valve and to the second high-pressure heater pipeline via a third regenerative valve, and the exhaust steam of the high-pressure regulating stage being connected to the first high-pressure heater pipeline via a fourth regenerative valve.

[0013] In some embodiments, a second valve is provided between the main steam valve and the high-pressure pre-stage. The exhaust outlet of the high-pressure pre-stage is connected to the steam outlet pipeline of the first valve via a third valve, and then connected to the steam inlet pipeline of the high-pressure cylinder. The exhaust outlet of the high-pressure pre-stage is connected to the reheat steam inlet pipeline of the boiler via a fourth valve. The steam inlet of the high-pressure cylinder is connected to the reheat steam pipeline via a first bypass valve. The exhaust outlet of the high-pressure cylinder is connected to the reheat steam pipeline via a second bypass valve. A reheat switching valve is also provided between the connection point of the first bypass valve to the reheat steam pipeline and the connection point of the second bypass valve to the reheat steam pipeline.

[0014] In some embodiments, a series regulating valve is provided between adjacent high-pressure pre-stages, with the inlet end of the series regulating valve connected to the exhaust outlet end of the preceding high-pressure pre-stage and the outlet end of the series regulating valve connected to the steam inlet end of the following high-pressure pre-stage.

[0015] In some embodiments, at least one of the high-pressure pre-stage exhaust outlets is provided with a shut-off valve.

[0016] In some embodiments, a plurality of the high-voltage preamplifiers are arranged in the same direction, or at least a pair of the high-voltage preamplifiers are arranged facing each other;

[0017] The multiple low-pressure regulating cylinders are arranged in the same direction, or at least one pair of the low-pressure regulating cylinders are arranged facing each other.

[0018] In some embodiments, the load rates of the turbine generator set's state reconfiguration point are set from largest to smallest as follows, based on the number n of the high-voltage front-end stages: X1, X2, ..., X... n %, sorted by flow area from smallest to largest, the flow area of ​​the nth high-pressure pre-stage is 0.4 (1-X) times the flow area of ​​the first stage of the high-pressure cylinder. n %) ~ 3 (1-X n %).

[0019] In some embodiments, based on the number m of the low-pressure regulating cylinders, the load rates of the state reconfiguration points of the steam turbine generator set are set from largest to smallest as Y1, Y2, ..., Y... m%, sorted by flow area from smallest to largest, the flow area of ​​the m-th low-pressure regulating cylinder is 0.4 (1-Y) times the flow area of ​​the first stage of the low-pressure cylinder. m %) ~ 3 (1-Y m %).

[0020] The third inventive point is to provide an operating method for a combined, adjustable, dynamically reconfigurable steam turbine generator set, including:

[0021] Several low-voltage reconfiguration load zones are divided within the low-load zone;

[0022] Different low-pressure reconfiguration load ranges are mapped and bound to different low-pressure regulating stage combinations. The low-pressure regulating stage combination consists of a single low-pressure regulating cylinder, or multiple low-pressure regulating cylinders connected in series, or multiple low-pressure regulating cylinders connected in series with a low-pressure cylinder.

[0023] If the current load or the set load is located in the low-voltage reconfiguration load range, the low-voltage regulating stage combination corresponding to the low-voltage reconfiguration load range shall be put into operation. The smaller the low-voltage reconfiguration load range, the smaller the total flow area of ​​the corresponding low-voltage regulating stage combination.

[0024] In some embodiments, low-pressure regulating cylinders are arranged sequentially along the first rotating shaft in order of increasing flow area. As the low-pressure reconfiguration load range becomes smaller, the total flow area of ​​the corresponding low-pressure regulating stage combination decreases by sequentially cutting off the low-pressure regulating cylinders in order of decreasing flow area.

[0025] In some embodiments, low-pressure regulating cylinders are arranged sequentially along the second rotating axis in order of increasing flow area. As the low-pressure reconfiguration load range becomes smaller, the low-pressure regulating stage combination replaces the low-pressure cylinders. The way to reduce the total flow area of ​​the corresponding low-pressure regulating stage combination is to sequentially remove the low-pressure regulating cylinders in order of decreasing flow area.

[0026] In some embodiments, several high-voltage reconfiguration load zones are divided within the low-load zone;

[0027] Different high-voltage reconfiguration load ranges are mapped and bound to different high-voltage regulating stage combinations. The high-voltage regulating stage combination consists of a single high-voltage front-end stage, or multiple high-voltage front-end stages are combined in series or parallel.

[0028] If the current load or the set load is in the high-pressure reconfiguration load range, the corresponding high-pressure regulating stage combination is connected in series before the high-pressure cylinder. The smaller the high-pressure reconfiguration load range, the larger the total flow area of ​​the corresponding high-pressure regulating stage combination.

[0029] In some embodiments, high-pressure pre-stages are arranged sequentially along the first or second rotating axis in order of increasing flow area. As the high-pressure reconfiguration load range becomes smaller, the total flow area of ​​the corresponding high-pressure regulating stage combination increases by connecting the high-pressure pre-stages in series to the steam pipeline network in order of decreasing flow area.

[0030] In some embodiments, a cold-reheat switching load point is set. If the current load or the set load is less than the cold-reheat switching load point, the exhaust steam of the high-pressure regulating stage is connected to the boiler, the exhaust steam of the high-pressure cylinder is blocked from entering the boiler, the reheat switching valve is closed, and the first bypass valve and the second bypass valve are opened so that the reheat steam enters the intermediate-pressure cylinder after passing through the high-pressure cylinder.

[0031] In some embodiments, in the initial state, the first regenerative valve and the third regenerative valve are opened, the second regenerative valve and the fourth regenerative valve are closed, the exhaust steam of the high-pressure cylinder is connected to the second high-pressure heater, and the intermediate extraction steam of the high-pressure cylinder is connected to the first high-pressure heater.

[0032] After the exhaust steam of the high-pressure regulating stage is connected to the cold reheat steam pipeline, the first reheat valve and the third reheat valve are closed, and the second reheat valve and the fourth reheat valve are opened. The intermediate extraction steam of the high-pressure cylinder is connected to the second high-pressure heater, and the exhaust steam of the high-pressure regulating stage is connected to the first high-pressure heater.

[0033] In some embodiments, the low-load condition is 10% to 80% of the rated load condition.

[0034] Compared with the prior art, the present invention has at least the following beneficial effects:

[0035] The turbine unit's operating load conditions are divided. Under low load conditions, as the load rate decreases, the total flow area of ​​the low-pressure zone is reduced by gradually disconnecting the low-pressure regulating cylinder, thus achieving dynamic reconfiguration of the low-pressure zone. Additionally, under low load conditions, a high-pressure regulating stage is connected in series before the high-pressure cylinder. Both the high-pressure regulating stage and the high-pressure cylinder are in operation, increasing the flow area of ​​the high-pressure zone, adding more power-generating components, and maintaining a higher unit operating pressure through pressure transmission. Therefore, this turbine unit achieves combined regulation and dynamic reconfiguration under low load conditions. The regulation of the high-pressure and low-pressure cylinders is independent and does not interfere with each other, improving adaptability to load conditions and avoiding the problem of a sharp drop in energy efficiency caused by a decrease in the main reheat steam operating pressure under low load conditions.

[0036] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0037] The present invention will be further described with reference to the accompanying drawings, but the embodiments in the drawings do not constitute any limitation on the present invention. For those skilled in the art, other drawings can be obtained based on the following drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the combined adjustable dynamic reconfiguration steam turbine generator set provided by the present invention in one embodiment.

[0039] Figure 2 This is a schematic diagram of another embodiment of the combined adjustable dynamic reconfiguration steam turbine generator set provided by the present invention.

[0040] Figure 3 This is a schematic diagram of a structure with a pair of high-voltage pre-stages arranged facing each other.

[0041] Reference numerals: 1 Boiler; 2 First shaft; 3 High-pressure cylinder; 4 Intermediate-pressure cylinder; 5 Low-pressure cylinder; 6 Main steam valve; 7 Main steam pipe; 8 Cold / reheat steam pipe; 9 Reheat steam pipe; 10 Second shaft; 20 High-pressure regulating stage group; 30 Low-pressure regulating stage group; 21 High-pressure pre-stage; 31 Low-pressure regulating cylinder; 41 First valve; 42 Second valve; 43 Third valve; 44 Fourth valve; 45 Fifth valve; 46 Sixth valve; 47 Seventh valve; 48 Eighth valve; 49th valve; 9. Valves; 50. Cold / Reheat Valve; 51. First Reheat Valve; 52. Second Reheat Valve; 53. Third Reheat Valve; 54. Fourth Reheat Valve; 55. Series Control Valve; 56. Shut-off Valve; 57. First Bypass Valve; 58. Second Bypass Valve; 59. Reheat Switching Valve; 61. Reheat System; 62. First High-Pressure Heater; 63. Second High-Pressure Heater; 64. Condenser; 65. Condensate Pump; 66. Low-Pressure Heater; 67. Deaerator; 68. Feedwater Pump; 69. Generator; 70. Energy Conversion Equipment. Detailed Implementation

[0042] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0044] In the description of this invention, when a specific device is described as being located between a first device and a second device, an intermediary device may or may not be present between the specific device and the first or second device. When a specific device is described as being connected to other devices, the specific device may be directly connected to the other devices without an intermediary device, or it may not be directly connected to the other devices but may have an intermediary device.

[0045] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0046] Firstly, referring to Figure 1 This embodiment 1 provides a combined adjustable dynamic reconfiguration steam turbine generator set, including a first rotating shaft 2, a low-pressure regulating stage group 30, and a low-pressure cylinder 5. The low-pressure cylinder 5 and the low-pressure regulating stage group 30 are arranged sequentially along the central axis of the first rotating shaft 2. In the direction of steam flow, the low-pressure cylinder 5 and the low-pressure regulating stage group 30 are arranged sequentially. The low-pressure regulating stage group 30 includes at least one low-pressure regulating cylinder 31 whose exhaust steam can be selectively connected to the condenser 64. Multiple low-pressure regulating cylinders 31 are connected in series with the low-pressure cylinder 5. The exhaust steam of the low-pressure cylinder 5 can be selectively connected to the condenser 64. The low-pressure regulating cylinder 31 and the low-pressure cylinder 5 form a low-pressure multi-stage reconfiguration cylinder group. The low-pressure multi-stage reconfiguration cylinder group is configured to disconnect the low-pressure regulating cylinder 31 step by step from back to front in the direction of steam flow when the load rate is lower than the set reconfiguration load.

[0047] It should be noted that the low-pressure regulating cylinder 31 can be controlled to discharge steam through the valve at the exhaust end and to receive steam through the valve at the inlet end. This allows control over whether the low-pressure regulating cylinder 31 discharges steam into the condenser 64. The low-pressure regulating stage group 30 and the low-pressure cylinder 5 are arranged coaxially. Under normal operating conditions, steam first enters the low-pressure cylinder 5 and then sequentially enters the low-pressure regulating cylinder 31. When the load rate decreases, the last stage of the low-pressure regulating cylinder 31 is cut off first. This is equivalent to the low-pressure multi-stage reconfiguration cylinder group being reconfigured, reducing the total flow area. As the load rate decreases, the low-pressure regulating cylinder 31 is cut off stage by stage from back to front, leaving only the low-pressure cylinder 5. This further adjusts and reduces the total flow area, improving the operating pressure and efficiency of the low-pressure zone.

[0048] In one implementation, the exhaust port of the intermediate-pressure cylinder 4 is connected to the low-pressure cylinder 5. The exhaust of the low-pressure cylinder 5 is connected to the condenser 64 through a valve. The exhaust of the low-pressure cylinder 5 is also connected to the next-stage low-pressure regulating cylinder 31 through a valve, and so on, to realize the series connection of the low-pressure multi-stage reconfigurable cylinder group.

[0049] Secondly, referring to Figure 2 This embodiment 2 provides a combined adjustable dynamic reconfiguration steam turbine generator set, including a first rotating shaft 2, a second rotating shaft 10, a low-pressure regulating stage group 30, and a low-pressure cylinder 5. The low-pressure cylinder 5 is arranged on the first rotating shaft 2, and the low-pressure regulating stage group 30 is arranged on the second rotating shaft 10. The second rotating shaft 10 is also connected to an energy conversion device 70. The low-pressure regulating stage group 30 is connected in parallel with the low-pressure cylinder 5. The low-pressure regulating stage group 30 includes at least one low-pressure regulating cylinder 31 whose exhaust steam can be selectively connected to the condenser 64. Multiple low-pressure regulating cylinders 31 are connected in series. The low-pressure regulating stage group 30 is configured to replace the low-pressure cylinder 5 in parallel when the load rate is lower than the set reconfiguration load, and the low-pressure regulating cylinders 31 can be disconnected step by step from back to front along the steam flow direction.

[0050] It should be noted that the low-pressure regulating cylinder 31 can be controlled to discharge steam via the valve at the discharge end, and its steam intake via the valve at the steam intake end. This allows control over whether the low-pressure regulating cylinder 31 discharges steam into the condenser 64. The low-pressure cylinder 5 and the low-pressure regulating stage group 30 are arranged off-axis. Under normal operating conditions, steam enters the low-pressure cylinder 5, and no steam flows through the low-pressure regulating stage group 30. When the load rate decreases, the low-pressure regulating stage group 30 is connected, and the low-pressure cylinder 5 is disconnected, allowing steam to enter the low-pressure regulating stage group 30 while no steam flows through the low-pressure cylinder 5. The low-pressure regulating stage group 30 replaces the operation of the low-pressure cylinder 5. As the load rate decreases, the low-pressure regulating cylinder 31 is disconnected step by step from the end to the beginning, further adjusting and reducing the total flow area of ​​the low-pressure zone, thereby improving the operating pressure and efficiency of the low-pressure zone.

[0051] Both of the above embodiments involve dynamic reconfiguration of the low-pressure zone of the turbine unit. Furthermore, multiple series-connected low-pressure regulating cylinders 31 can be set up, and by gradually cutting them off, the total flow area can be reconfigured to a suitable level under multiple load rates to improve the adaptability of operating conditions.

[0052] In one implementation, the exhaust port of the intermediate-pressure cylinder 4 is connected to the inlet of the low-pressure cylinder 5 via the fifth valve 45 and to the inlet of the low-pressure regulating stage group 30 via the sixth valve 46. The low-pressure regulating stage group 30 includes two low-pressure regulating cylinders 31. The exhaust port of the front low-pressure regulating cylinder 31 is connected to the inlet of the rear low-pressure regulating cylinder via the seventh valve 47, and the exhaust port of the front low-pressure regulating cylinder is also connected to the exhaust of the low-pressure cylinder 5 via the eighth valve 48. The exhaust port of the rear low-pressure regulating cylinder is connected to the exhaust of the low-pressure cylinder 5 via the ninth valve 49. The seventh valve 47 can control whether the front and rear low-pressure regulating cylinders are connected in series, and the eighth valve 48 and the ninth valve 49 are used to realize the exhaust access.

[0053] Example 3:

[0054] Reference Figure 1 and Figure 2 In this embodiment 3, it also includes a boiler 1, a high-pressure cylinder 3, a medium-pressure cylinder 4, and a high-pressure regulating stage 20. The main steam outlet of the boiler 1 is connected to the steam inlet of the high-pressure cylinder 3 through a main steam pipe 7. A main steam valve 6 is provided on the main steam pipe 7. The exhaust outlet of the high-pressure cylinder 3 is connected to the reheat steam inlet of the boiler 1 through a cold reheat steam pipe 8. The reheat steam outlet of the boiler 1 is connected to the steam inlet of the medium-pressure cylinder 4 through a reheat steam pipe 9. The steam outlet of the medium-pressure cylinder 4 is connected to the steam inlet of the low-pressure cylinder 5. The high-pressure cylinder 3, the medium-pressure cylinder 4, and the low-pressure cylinder 5 are arranged sequentially along the central axis of the first rotating shaft 2.

[0055] A first valve 41 is provided between the main steam valve 6 and the high-pressure cylinder 3. The high-pressure regulating stage group 20 is connected in parallel with the first valve 41. When the first valve 41 is open, it is equivalent to the high-pressure regulating stage group 20 being short-circuited. The main steam enters the high-pressure cylinder 3 from the first valve 41 without passing through the high-pressure regulating stage group 20. When the first valve 41 is closed, it is equivalent to connecting the high-pressure regulating stage group 20 in series before the high-pressure cylinder 3. The main steam passes through the high-pressure regulating stage group 20 first and then enters the high-pressure cylinder 3.

[0056] The high-pressure regulating stage group 20 includes at least one high-pressure pre-stage 21 that can be selectively connected to the steam pipeline network. Multiple high-pressure pre-stages 21 are connected in series or parallel. It should be noted that the series connection between the high-pressure regulating stage group 20 and the high-pressure cylinder 3 is described from the perspective of steam flow, not power output. The high-pressure regulating stage group 20 connected in series before the high-pressure cylinder 3 can have various flow area states because it can selectively connect different high-pressure pre-stages 21 to the steam pipeline network. For example, in this embodiment, there are two high-pressure pre-stages 21, one before the other. The flow area of ​​the latter high-pressure pre-stage 21 is larger. As the load decreases, the flow area begins to decrease. When the high-pressure regulating stage group 20 is connected in series, the subsequent high-pressure pre-stage 21 is first connected to the steam network, so that the main steam passes through the subsequent high-pressure pre-stage 21 before entering the high-pressure cylinder 3. When the load decreases further, the preceding high-pressure pre-stage 21 is connected to the steam network on the existing basis, and the two high-pressure pre-stages 21 are connected in series, that is, the main steam passes through the preceding high-pressure pre-stage 21 and the subsequent high-pressure pre-stage 21 in sequence before entering the high-pressure cylinder 3, so as to form a combined regulation. In addition, in order to facilitate the exhaust steam regulation of the high-pressure regulating stage group 20, the exhaust steam of the high-pressure regulating stage group 20 can be selectively connected to the cold reheat steam pipeline 8 to change the steam state at the reheat inlet of boiler 1.

[0057] Of course, the number of high-pressure pre-stage 21 and low-pressure regulating cylinder 31 can be set according to the actual flow area requirements of high-pressure cylinder 3 and low-pressure cylinder 5 under low load. The state changes of high-pressure regulating stage group 20 and low-pressure regulating stage group 30 do not interfere with each other and are adjusted independently. The state reconstruction process of high-pressure regulating stage group 20 and low-pressure regulating stage group 30 is equivalent to gradually reconstructing the original high-pressure cylinder 3, medium-pressure cylinder 4 and low-pressure multi-stage reconstructed cylinder group or low-pressure cylinder 5 into high-pressure regulating stage group 20, high-pressure cylinder 3, medium-pressure cylinder 4 and low-pressure multi-stage reconstructed cylinder group. The pressure cylinder 5 or the low-pressure regulating cylinder 31 is used because, as the load decreases, the number of high-pressure pre-stage 21 connected gradually increases from the initial state of only one high-pressure pre-stage 21 to the state of the low-pressure cylinder body with the largest total flow area. The low-pressure regulating cylinder 31 is gradually removed, and finally, in the case of off-axis operation, only one low-pressure regulating cylinder 31 is retained, or in the case of coaxial operation, only the original low-pressure cylinder 5 is retained. This realizes the reconstruction of the entire working cylinder body of the turbine generator set, so as to adapt to low-load operation and improve the adaptability to load conditions.

[0058] As for the power output mode of the high-pressure regulating stage group 20 and the high-pressure cylinder 3, they can be linked in a coaxial or non-coaxial manner. In one embodiment, a coaxial manner is adopted, with the high-pressure regulating stage group 20 arranged on the first rotating shaft 2, and the low-pressure regulating stage group 30 also arranged on the first rotating shaft 2. The high-pressure regulating stage group 20, the high-pressure cylinder 3, the intermediate-pressure cylinder 4, the low-pressure regulating stage group 30 and the low-pressure cylinder 5 are arranged sequentially on the first rotating shaft 2. In another embodiment, a non-coaxial manner is adopted, with the high-pressure regulating stage group 20 arranged on the second rotating shaft 10, and the low-pressure regulating stage group 30 also arranged on the second rotating shaft 10. The high-pressure regulating stage group 20 and the low-pressure regulating stage group 30 are arranged sequentially on the second rotating shaft 10, and the high-pressure cylinder 3, the intermediate-pressure cylinder 4 and the low-pressure cylinder 5 are arranged sequentially on the first rotating shaft 2.

[0059] In one implementation, the connection point between the exhaust steam of the high-pressure cylinder 3 and the cold reheat steam pipeline 8 is the first cold reheat connection point, and the connection point between the exhaust steam of the high-pressure regulating stage group 20 and the cold reheat steam pipeline 8 is the second cold reheat connection point. A cold reheat valve 50 is provided between the first and second cold reheat connection points. By controlling the cold reheat valve 50, it is possible to choose whether to connect the exhaust steam of the high-pressure cylinder 3 to the cold reheat steam pipeline 8 or to connect the exhaust steam of the high-pressure regulating stage group 20 to the cold reheat steam pipeline 8. This is equivalent to controlling the connection between the first or second cold reheat connection point and the boiler 1 by controlling the cold reheat valve 50. As the turbine generator set is dynamically reconfigured, when the high-pressure regulating stage group 20 actually functions as the high-pressure cylinder 3, it is necessary to connect the exhaust steam of the high-pressure regulating stage to the cold reheat steam pipeline 8 so that the exhaust steam can enter the boiler 1 for reheating.

[0060] It should be noted that since the high-pressure regulating stage group 20 has multiple high-pressure pre-stages 21, each high-pressure pre-stage 21 can be selectively connected to the cold reheat steam pipeline 8. When the exhaust steam from the high-pressure pre-stage 21 and the exhaust steam from the high-pressure cylinder 3 are simultaneously discharged into the cold reheat steam pipeline 8, the cold reheat valve 50 is not closed. When the exhaust steam is completely switched to the high-pressure pre-stage 21, the cold reheat valve 50 is closed. That is, there are multiple regulating states for the exhaust steam connection of the high-pressure pre-stage 21 to adapt to different load conditions and reheat requirements.

[0061] As one implementation, a regenerative system 61 is also included. The regenerative system 61 includes a first high-pressure heater 62 and a second high-pressure heater 63. The conventional second extraction port of the high-pressure cylinder 3 is connected to the second high-pressure heater 63 via a first regenerative valve 51. The conventional first extraction port of the high-pressure cylinder 3 is connected to the first high-pressure heater 62 via a second regenerative valve 52 and to the second high-pressure heater 63 via a third regenerative valve 53. The cold reheat steam pipeline 8 is connected to the first high-pressure heater 62 via a fourth regenerative valve 54. The conventional first extraction port is the intermediate extraction port of the high-pressure cylinder 3, and the conventional second extraction port is the exhaust port of the high-pressure cylinder 3. The access point of the fourth regenerative valve 54 in the cold reheat steam pipeline 8 is closer to the boiler 1 than the access point of the high-pressure regulating stage group 20. That is, after the exhaust steam from the high-pressure regulating stage group 20 enters the cold reheat steam pipeline 8, it then enters the first high-pressure heater 62 via the fourth regenerative valve 54. More detailed... In the initial state, the first regenerative valve 51 and the third regenerative valve 53 are open, while the second regenerative valve 52 and the fourth regenerative valve 54 are closed. The exhaust steam from the high-pressure cylinder 3 is connected to the second high-pressure heater 63, and the intermediate extraction steam from the high-pressure cylinder 3 is connected to the first high-pressure heater 62. When switching to fully connecting the exhaust steam from the high-pressure regulating stage to the cold reheat steam pipeline 8, the first regenerative valve 51 and the third regenerative valve 53 are closed, and the second regenerative valve 52 and the fourth regenerative valve 54 are opened. The intermediate extraction steam from the high-pressure cylinder 3 is connected to the second high-pressure heater 63, and the exhaust steam from the high-pressure regulating stage group 20 is connected to the first high-pressure heater 62. This is because when the high-pressure regulating stage exhaust steam is fully connected to the cold reheat steam pipeline 8, the temperature and pressure of the high-pressure regulating stage exhaust steam are already higher than those of the intermediate extraction steam from the high-pressure cylinder 3. At this time, it is necessary to connect the high-pressure regulating stage exhaust steam with higher temperature and pressure to the first high-pressure heater 62 to complete the regenerative step and achieve the set regenerative requirements.

[0062] In this embodiment, a second valve 42 is provided between the main steam valve 6 and the high-pressure pre-stage 21. The first valve 41 and the second valve 42 control whether the main steam enters the cylinder corresponding to the valve. The exhaust outlet of the high-pressure pre-stage 21 is connected to the steam outlet pipeline of the first valve 41 via a third valve 43, and then connected to the steam inlet pipeline of the high-pressure cylinder 3. The exhaust outlet of the high-pressure pre-stage 21 is connected to the reheat steam inlet pipeline of the boiler 1 via a fourth valve 44. That is, the exhaust of each high-pressure pre-stage 21 can be selectively connected to the cold reheat steam pipeline 8. Regardless of which high-pressure pre-stage 21 is connected, the steam will enter the cold reheat steam pipeline 8 after passing through multiple high-pressure pre-stages 21 connected in series. It should be noted that the second valve 42 and the third valve 43 have a one-to-one correspondence with the high-pressure pre-stage 21.

[0063] In one implementation, the steam inlet of the high-pressure cylinder 3 is connected to the reheat steam pipeline 9 via a first bypass valve 57, and the exhaust outlet of the high-pressure cylinder 3 is connected to the reheat steam pipeline 9 via a second bypass valve 58. A reheat switching valve 59 is also provided between the connection point of the first bypass valve 57 to the reheat steam pipeline 9 and the connection point of the second bypass valve 58 to the reheat steam pipeline 9. When the connection is fully made to connect the exhaust of the high-pressure regulating stage 20 to the cold reheat steam pipeline 8, the cold reheat valve 50 and the reheat switching valve 59 can be closed. Open the first bypass valve 57 and the second bypass valve 58 so that steam exits from boiler 1 and enters the high-pressure regulating stage group 20. Then, it enters boiler 1 for reheating through the cold reheat steam pipeline 8, and then enters the high-pressure cylinder 3 through the first bypass valve 57 via the reheat steam pipeline 9. After being discharged from the high-pressure cylinder 3, it enters the reheat steam pipeline 9 through the second bypass valve 58 and flows into the intermediate-pressure cylinder 4. This realizes the reconfiguration of the unit state. That is, with the reconfiguration of the working cylinder, the reheat and regeneration states in the unit are reconfigured together, so that the system can adapt to low-load conditions for a long time.

[0064] In one implementation, a series regulating valve 55 is provided between adjacent high-pressure pre-stages 21. The inlet end of the series regulating valve 55 is connected to the exhaust outlet end of the preceding high-pressure pre-stage 21, and the outlet end of the series regulating valve 55 is connected to the steam inlet end of the following high-pressure pre-stage 21. If the series regulating valve 55 is connected, the high-pressure pre-stages 21 located before and after it are connected in series. Correspondingly, the second valve 42 of the following high-pressure pre-stage 21 and the third valve 43 of the preceding pressure regulating stage will be closed, so that steam enters from the steam inlet end of the preceding high-pressure pre-stage 21, performs work, and then enters the following high-pressure pre-stage 21, completing the series connection. In addition, by controlling the valves, any series and parallel connection of high-pressure pre-stages 21 can be realized to form a variety of combination modes.

[0065] In one embodiment, at least one high-pressure pre-stage 21 is provided with a shut-off valve 56 at its exhaust outlet end, which is used to prevent steam from flowing back into the high-pressure pre-stage 21.

[0066] Combination Figure 1 In one implementation, multiple high-pressure pre-stages 21 are arranged in the same direction, and multiple low-pressure regulating cylinders 31 are arranged in the same direction. Preferably, they are arranged in the same direction in order of increasing flow area to reduce the overall arrangement volume.

[0067] Combination Figure 3 As another implementation, at least one pair of high-pressure pre-stages 21 are arranged facing each other, and at least one pair of low-pressure regulating cylinders 31 are arranged facing each other, that is, the steam inlet ends of the two regulating stages are arranged opposite each other, which can improve the operating stability of the second rotating shaft 10 and reduce noise.

[0068] Additionally, as a further improvement to the above embodiment, the first rotating shaft 2 is also connected to a generator 69, and the exhaust outlet of the low-pressure cylinder 5 is connected to a condenser 64. The condensate outlet of the condenser 64 is connected in sequence to a condensate pump 65, a low-pressure heater 66, a deaerator 67, a feedwater pump 68, a high-pressure heater, and the boiler 1 feedwater inlet through pipelines, thereby forming a circulation. There are multiple low-pressure heaters 66 and high-pressure heaters.

[0069] In this embodiment, based on the number n of high-voltage pre-stages 21, the load rates of the turbine generator set's state reconfiguration points are set from largest to smallest as X1, X2, ..., X... n %, sorted by flow area from smallest to largest, the flow area of ​​the nth high-pressure pre-stage 21 is 0.4 (1-X) times the flow area of ​​the first stage of the high-pressure cylinder 3. n %) ~ 3 (1-X n %).

[0070] Based on the number of low-pressure regulating cylinders m, the load rates at the state reconfiguration points of the turbine generator set are set from largest to smallest as Y1, Y2, ..., Y... m %, sorted by flow area from smallest to largest, the flow area of ​​the m-th low-pressure regulating cylinder is 0.4 (1-Y) times the flow area of ​​the first stage of low-pressure cylinder 5. m %) ~ 3 (1-Y m %).

[0071] It should be noted that X n % and Y m The percentage ranges from 30% to 70%. At each load rate representing a state reconfiguration point, the high-pressure regulating stage group 20 and the low-pressure regulating stage group 30 will put the corresponding front-end stage into operation. As the load rate decreases from high to low, the high-pressure regulating stage group 20 gradually connects to the high-pressure front-end stage 21, while the low-pressure regulating stage group 30 gradually disconnects the low-pressure regulating cylinder 31, realizing the dynamic reconfiguration of the entire unit. The load rate at the state reconfiguration point is the indicator of the switching action of the gradual reconfiguration, set according to the above ratio.

[0072] Thirdly, this embodiment 4 provides an operation method for a combined regulating dynamic reconfiguration steam turbine generator set, including:

[0073] Within the low-load range, several low-voltage reconfiguration load ranges are defined, such as setting the load rate of the turbine generator unit's state reconfiguration point as Y1, Y2, ..., Y... m The low-voltage reconfiguration load ranges, from largest to smallest, are [Y1, Y2) ... [Y...]. m-1 Y m );

[0074] Different low-pressure reconfiguration load ranges are mapped and bound to different low-pressure regulating stage combinations. Each low-pressure reconfiguration load range has a corresponding low-pressure regulating stage combination. The low-pressure regulating stage combination consists of a single low-pressure regulating cylinder 31, or multiple low-pressure regulating cylinders 31 connected in series or parallel, or multiple low-pressure regulating cylinders 31 connected in series with low-pressure cylinder 5. The flow area of ​​each low-pressure regulating cylinder 31 is not the same. By connecting them in series or parallel, various flow area situations can be formed.

[0075] This operating method can be used to adjust the load based on the current load value, or it can be used to actively adjust the load after setting it. Therefore, it is necessary to determine which load range the current load or the set load belongs to:

[0076] If the current load or the set load is in the low-voltage reconfiguration load range, the low-voltage regulating stage combination corresponding to the low-voltage reconfiguration load range will be put into operation according to the actual load range. The smaller the low-voltage reconfiguration load range, the smaller the total flow area of ​​the corresponding low-voltage regulating stage combination. That is, as the load continues to decrease, the number of low-voltage regulating cylinders 31 connected will decrease.

[0077] More specifically, in some possible implementations, the low-pressure cylinder 5 is coaxially arranged with the low-pressure regulating stage group 30, and the low-pressure regulating cylinders 31 are arranged sequentially along the first rotating shaft 2 in order of increasing flow area. The low-pressure cylinder 5 is located before the low-pressure regulating stage group 30. As the low-pressure reconfiguration load range becomes smaller, the total flow area of ​​the corresponding low-pressure regulating stage group decreases by sequentially cutting off the low-pressure regulating cylinders 31 in order of decreasing flow area, that is, sequentially cutting off the low-pressure regulating cylinders 31 from the end.

[0078] In some possible implementations, the low-pressure cylinder 5 and the low-pressure regulating stage group 30 are arranged off-axis. The low-pressure regulating cylinders 31 are arranged sequentially along the second rotating shaft 10 in order of increasing flow area. When the load rate is lower than the set reconfiguration load, the low-pressure regulating stage group replaces the low-pressure cylinder 5. As the low-pressure reconfiguration load range becomes smaller, the total flow area of ​​the corresponding low-pressure regulating stage group decreases by sequentially cutting off the low-pressure regulating cylinders 31 in order of decreasing flow area. That is, when entering the largest low-pressure reconfiguration load range, all the low-pressure regulating cylinders 31 are connected in series to replace the original low-pressure cylinder 5. As the low-pressure reconfiguration load range becomes smaller, the low-pressure regulating cylinders 31 are cut off from back to front, i.e., in order of decreasing flow area, so that the flow area of ​​the low-pressure regulating stage group 30 gradually decreases.

[0079] Example 5:

[0080] In this embodiment 5, several high-voltage reconfiguration load intervals are divided within the low-load interval. For example, the load rate of the state reconfiguration point of the steam turbine generator set is set as X1, X2, ... X... n%, then the high-voltage reconfiguration load ranges from largest to smallest are [X1, X2) ... [X n-1 X n );

[0081] Different high-voltage reconfiguration load ranges are mapped and bound to different high-voltage regulating stage combinations. Each high-voltage reconfiguration load range has a corresponding high-voltage regulating stage combination. The high-voltage regulating stage combination consists of a single high-voltage pre-stage 21, or multiple high-voltage pre-stages 21 connected in series or parallel. The flow area of ​​each high-voltage pre-stage 21 is not the same. By connecting them in series or parallel, various flow area situations can be formed.

[0082] If the current load or the set load is in the high-voltage reconfiguration load range, according to the actual load range entered, the corresponding high-voltage regulating stage combination is connected in series before the high-voltage cylinder 3. The smaller the high-voltage reconfiguration load range, the larger the total flow area of ​​the corresponding high-voltage regulating stage combination. That is, as the load continues to decrease, more and more high-voltage pre-stages 21 are connected.

[0083] In one implementation, high-pressure pre-stages 21 are arranged sequentially along the first rotating shaft 2 or the second rotating shaft 10 in order of increasing flow area. As the high-pressure reconfiguration load range becomes smaller, the total flow area of ​​the corresponding high-pressure regulating stage combination increases. This is achieved by connecting the high-pressure pre-stages 21 in series to the steam pipeline network in order of decreasing flow area. That is, when entering the largest high-pressure reconfiguration load range, only the high-pressure pre-stage 21 with the largest flow area is connected. As the load range becomes smaller, high-pressure pre-stages 21 with increasingly smaller flow areas are connected in series from back to front, based on the last high-pressure pre-stage 21.

[0084] As one implementation method, a cold-reheat switching load point is set. If the current load or the set load is less than the cold-reheat switching load point, it means that the high-pressure regulating stage group 20 is actually acting as the high-pressure cylinder 3. Then, the cold-reheat valve 50 is closed, the exhaust steam of the high-pressure regulating stage group 20 is connected to the cold-reheat steam pipeline 8, the exhaust steam of the high-pressure cylinder 3 is blocked from entering the cold-reheat steam pipeline 8, and the exhaust steam of the high-pressure regulating stage group 20 is used for reheating. The reheat switching valve 59 is closed, and the first bypass valve 57 and the second bypass valve 58 are opened, so that the reheat steam enters the intermediate-pressure cylinder 4 after passing through the high-pressure cylinder 3. In addition, in this switching state, the steam inlet of the high-pressure cylinder 3 is cut off from the high-pressure regulating stage group 20 through the steam inlet shut-off valve 56, and the steam inlet of the high-pressure cylinder 3 can only be reheat steam.

[0085] In one implementation, in the initial state, the first regenerative valve 51 and the third regenerative valve 53 are opened, the second regenerative valve 52 and the fourth regenerative valve 54 are closed, the exhaust steam of the high-pressure cylinder 3 is connected to the second high-pressure heater 63, and the intermediate extraction steam of the high-pressure cylinder 3 is connected to the first high-pressure heater 62.

[0086] When switching to connect the exhaust steam of the high-pressure regulating stage group 20 to the cold reheat steam pipeline 8, close the first reheat valve 51 and the third reheat valve 53, open the second reheat valve 52 and the fourth reheat valve 54, connect the intermediate extraction steam of the high-pressure cylinder 3 to the second high-pressure heater 63, and connect the exhaust steam of the high-pressure regulating stage group 20 to the first high-pressure heater 62. Because the temperature and pressure of the exhaust steam of the high-pressure regulating stage are already higher than those of the intermediate extraction steam of the high-pressure cylinder 3, it is necessary to connect the high-pressure regulating stage exhaust steam with higher temperature and pressure to the first high-pressure heater 62 to complete the reheating step and achieve the set reheating requirements.

[0087] When the load is continuously decreasing, the power efficiency is improved by reconfiguring the high-pressure regulating stage group 20 and the low-pressure regulating stage group 30, and a better reheat and recuperation mode is switched, so that the reconfigured unit has better thermal efficiency and more stable operation.

[0088] Preferably, the low load condition is 10% to 80% of the rated load condition, and the high load condition is not less than 80% of the rated load condition. The number of high-pressure pre-stage 21 and low-pressure regulating cylinder 31 can be the same, and the division of the high-pressure reconfiguration load range and the low-pressure reconfiguration load range is the same.

[0089] In summary, compared to existing technologies, the above embodiments provide a combined-regulation dynamic reconfiguration steam turbine generator set and its operation method. The turbine unit's operating load conditions are divided. Under low-load conditions, as the load rate decreases, the total flow area of ​​the low-pressure zone of the turbine unit is reduced by gradually disconnecting the low-pressure regulating cylinder 31, thus achieving dynamic reconfiguration of the low-pressure zone. Furthermore, under low-load conditions, a high-pressure regulating stage group 20 is connected in series before the high-pressure cylinder 3. Both the high-pressure regulating stage group 20 and the high-pressure cylinder 3 are in operation, increasing the flow area of ​​the high-pressure zone, increasing the number of power-generating stages, and maintaining a higher unit operating pressure through pressure transmission. Therefore, this steam turbine unit achieves combined-regulation dynamic reconfiguration under low-load conditions. The regulation of the high-pressure cylinder 3 and the low-pressure cylinder 5 is independent and does not interfere with each other, improving adaptability to load conditions and avoiding the problem of a sharp drop in energy efficiency caused by the decrease in the main reheat steam operating pressure under low-load conditions.

[0090] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A combined cycle, dynamically reconfigurable steam turbogenerator unit, characterized in that, The low-pressure cylinder and the low-pressure adjusting stage group are arranged along the central axis direction of the first rotating shaft in sequence, the low-pressure adjusting stage group comprises at least one low-pressure adjusting cylinder with exhaust steam selectively connected to the condenser, a plurality of the low-pressure adjusting cylinders are connected in series with the low-pressure cylinder, the low-pressure cylinder has exhaust steam selectively connected to the condenser, the low-pressure adjusting cylinder and the low-pressure cylinder form a low-pressure multi-stage reconfiguration cylinder group, the low-pressure multi-stage reconfiguration cylinder group is configured to sequentially cut off the low-pressure adjusting cylinders from back to front in the steam flow direction when the load rate is lower than the set reconfiguration load; wherein the exhaust steam of the low-pressure cylinder is connected to the next low-pressure adjusting cylinder through a valve, a plurality of low-pressure adjusting cylinders connected in series are arranged to realize the series connection of the low-pressure multi-stage reconfiguration cylinder group.

2. A combined cycle, dynamically reconfigurable steam turbogenerator unit, characterized in that, The low-pressure cylinder is arranged on the first rotating shaft, the low-pressure adjusting stage group is arranged on the second rotating shaft, the low-pressure adjusting stage group is connected in parallel with the low-pressure cylinder, the low-pressure adjusting stage group comprises at least one low-pressure adjusting cylinder with exhaust steam selectively connected to the condenser, a plurality of the low-pressure adjusting cylinders are connected in series, the exhaust port of the front low-pressure adjusting cylinder is connected to the steam inlet port of the rear low-pressure adjusting cylinder through a valve, and whether the front and rear low-pressure adjusting cylinders are connected in series can be controlled through the valve; the low-pressure adjusting stage group is configured to replace the low-pressure cylinder in parallel and sequentially cut off the low-pressure adjusting cylinders from back to front in the steam flow direction when the load rate is lower than the set reconfiguration load.

3. A combined regulated dynamic reconfiguration steam turbine generator unit according to claim 1 or 2, characterized in that, The high-pressure adjusting stage group is arranged on the first rotating shaft, and the high-pressure cylinder, the intermediate-pressure cylinder, the low-pressure adjusting stage group and the low-pressure cylinder are arranged on the first rotating shaft in sequence.

4. A combined governing dynamically reconfigured turbogenerator unit according to claim 3, characterized in that The high-pressure adjusting stage group is arranged on the second rotating shaft, and the high-pressure adjusting stage group and the low-pressure adjusting stage group are arranged on the second rotating shaft in sequence, and the high-pressure cylinder, the intermediate-pressure cylinder and the low-pressure cylinder are arranged on the first rotating shaft in sequence.

5. A combined governing dynamically reconfigured turbogenerator unit according to claim 3, characterized in that ​ 6. A combined-conditioning dynamic reconfiguration steam turbine generator unit according to claim 4 or 5, characterized in that, The access point of the high-pressure cylinder exhaust steam to the cold reheat steam pipeline is a first cold reheat access point, and the access point of the high-pressure regulating stage group exhaust steam to the cold reheat steam pipeline is a second cold reheat access point, and the first and second cold reheat access points are selectively accessible to the boiler.

7. A combined governing dynamically reconfigured turbogenerator unit according to claim 6, characterized in that The reheat system further comprises a first high-pressure heater and a second high-pressure heater, the conventional second extraction port of the high-pressure cylinder is connected to the pipeline of the second high-pressure heater through a first reheat valve, the conventional first extraction port of the high-pressure cylinder is connected to the pipeline of the first high-pressure heater through a second reheat valve and to the pipeline of the second high-pressure heater through a third reheat valve, and the high-pressure regulating stage group exhaust steam is connected to the pipeline of the first high-pressure heater through a fourth reheat valve.

8. A combined governing dynamically reconfigured turbogenerator unit according to claim 5, characterized in that The second valve is arranged between the main steam valve and the high-pressure pre-stage, the exhaust outlet end of the high-pressure pre-stage is connected to the first valve steam outlet end pipeline through a third valve, and then connected to the steam inlet end pipeline of the high-pressure cylinder, the exhaust outlet end of the high-pressure pre-stage is connected to the reheat steam inlet end pipeline of the boiler through a fourth valve, the steam inlet end of the high-pressure cylinder is connected to the reheat steam pipeline through a first bypass valve, the exhaust outlet end of the high-pressure cylinder is connected to the reheat steam pipeline through a second bypass valve, and a reheat switching valve is further arranged between the access point of the first bypass valve to the reheat steam pipeline and the access point of the second bypass valve to the reheat steam pipeline.

9. A combined governing dynamically reconfigured turbogenerator unit according to claim 8, characterized in that A series regulating valve is arranged between adjacent high-pressure pre-stages, the inlet end of the series regulating valve is connected to the exhaust outlet end of the preceding high-pressure pre-stage, and the outlet end of the series regulating valve is connected to the steam inlet end of the following high-pressure pre-stage.

10. A combined governing dynamically reconfigured turbogenerator unit according to claim 9, characterized in that The exhaust outlet end of at least one high-pressure pre-stage is provided with a stop valve.

11. A combined governing dynamically reconfigured turbogenerator unit according to claim 10, characterized in that The plurality of high-pressure pre-stages are arranged in the same direction, or at least one pair of high-pressure pre-stages are arranged in opposite directions. The plurality of low-pressure regulating cylinders are arranged in the same direction, or at least one pair of low-pressure regulating cylinders are arranged in opposite directions.

12. A combined governing dynamically reconfigured turbogenerator unit according to claim 3, characterized in that According to the number n of high-pressure pre-stages, the load rates of the state reconstruction points of the steam turbine generator unit are set from large to small as X1, X2, …, Xn%, and the flow areas are sorted from small to large, and the flow area of the nth high-pressure pre-stage is 0.4(1-Xn%)~3(1-Xn%) of the first-stage flow area of the high-pressure cylinder.

13. A combined governing dynamically reconfigured turbogenerator unit according to claim 3, characterized in that According to the number m of low-pressure regulating cylinders, the load rates of the state reconstruction points of the steam turbine generator unit are set from large to small as Y1, Y2, …, Ym%, and the flow areas are sorted from small to large, and the flow area of the mth low-pressure regulating cylinder is 0.4(1-Ym%)~3(1-Ym%) of the first-stage flow area of the low-pressure cylinder.

14. A method for operating a combined-regulation dynamically reconfigurable steam turbine generator unit, applied to a combined-regulation dynamically reconfigurable steam turbine generator unit according to any one of claims 1 to 13, characterized in that, The method comprises: dividing a low-load range into a plurality of low-pressure reconstruction load ranges; mapping and binding different low-pressure reconstruction load ranges with different low-pressure regulating combinations, the low-pressure regulating combination being composed of a single low-pressure regulating cylinder, or a plurality of low-pressure regulating cylinders connected in series, or a plurality of low-pressure regulating cylinders connected with a low-pressure cylinder in series; and the load rate of the state reconstruction point of the steam turbine generator unit is set from large to small as X1, X2, …, Xn%, and the flow areas are sorted from small to large, and the flow area of the nth high-pressure pre-stage is 0.4(1-Xn%)~3(1-Xn%) of the first-stage flow area of the high-pressure cylinder. If the current load or the set load is in the low-pressure reconstruction load interval, the low-pressure adjustment stage corresponding to the low-pressure reconstruction load interval is put into operation, wherein the smaller the low-pressure reconstruction load interval, the smaller the total flow area of the corresponding low-pressure adjustment stage combination.

15. The operation method of the combined adjustment type dynamic reconstruction steam turbine generator unit according to claim 14, characterized in that, the low-pressure adjustment cylinders are arranged along the first rotating shaft in the order of the flow area from small to large, and the smaller the low-pressure reconstruction load interval, the smaller the total flow area of the corresponding low-pressure adjustment stage combination, and the low-pressure adjustment cylinders are sequentially cut off in the order of the flow area from large to small.

16. The operation method of the combined adjustment type dynamic reconstruction steam turbine generator unit according to claim 14, characterized in that, the low-pressure adjustment cylinders are arranged along the second rotating shaft in the order of the flow area from small to large, and the smaller the low-pressure reconstruction load interval, the smaller the total flow area of the corresponding low-pressure adjustment stage combination, and the low-pressure adjustment cylinders are sequentially cut off in the order of the flow area from large to small.

17. The operation method of the combined adjustment type dynamic reconstruction steam turbine generator unit according to any one of claims 14 to 16, characterized in that, a plurality of high-pressure reconstruction load intervals are divided in the low load interval; different high-pressure reconstruction load intervals are mapped and bound with different high-pressure adjustment stage combinations, and the high-pressure adjustment stage combination is composed of a single high-pressure front stage, or a plurality of high-pressure front stages are connected in series or in parallel to form a combination; if the current load or the set load is in the high-pressure reconstruction load interval, the corresponding high-pressure adjustment stage combination is connected in series in front of the high-pressure cylinder, wherein the smaller the high-pressure reconstruction load interval, the larger the total flow area of the corresponding high-pressure adjustment stage combination.

18. The operation method of the combined adjustment type dynamic reconstruction steam turbine generator unit according to claim 17, characterized in that, the high-pressure front stages are arranged along the first rotating shaft or the second rotating shaft in the order of the flow area from small to large, and the smaller the high-pressure reconstruction load interval, the larger the total flow area of the corresponding high-pressure adjustment stage combination, and the high-pressure front stages are sequentially connected in series to the steam pipe network in the order of the flow area from large to small.

19. The operation method of the combined adjustment type dynamic reconstruction steam turbine generator unit according to claim 18, characterized in that, a cold reheat switching load point is set, if the current load or the set load is less than the cold reheat switching load point, the exhaust steam of the high-pressure adjustment stage combination is connected to the boiler, the exhaust steam of the high-pressure cylinder is cut off from entering the boiler, the reheat switching valve is closed, the first bypass valve and the second bypass valve are opened, and the reheat steam enters the intermediate-pressure cylinder after passing through the high-pressure cylinder.

20. The operation method of the combined adjustment type dynamic reconstruction steam turbine generator unit according to claim 19, characterized in that, In the initial state, the first and third regenerative valves are opened, the second and fourth regenerative valves are closed, the exhaust steam of the high-pressure cylinder is connected to the second high-pressure heater, and the intermediate extraction steam of the high-pressure cylinder is connected to the first high-pressure heater; After the exhaust steam of the high-pressure regulating stage group is connected to the cold reheat steam pipeline, the first and third regenerative valves are closed, the second and fourth regenerative valves are opened, the intermediate extraction steam of the high-pressure cylinder is connected to the second high-pressure heater, and the exhaust steam of the high-pressure regulating stage group is connected to the first high-pressure heater.

21. The method of operating a combined-conditioned dynamically reconfigurable turbogenerator unit of claim 18, wherein, The low-load working condition is 10% to 80% of the rated load working condition.

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