Methods, systems, equipment and media for load reduction control of dual-shaft steam turbine generator sets

Abstract

This invention discloses a load reduction control method, system, equipment, and medium for a dual-shaft steam turbine generator set. Under emergency conditions such as boiler main auxiliary equipment tripping, separate failures of the high- and low-level steam turbines and their generators, or disconnection of the main transformer from the busbar, the boiler and remaining steam turbines can automatically and synchronously reduce their load rapidly. The bypass system coordinates the control, enabling the main process parameters of the unit to smoothly decrease to the safe operating range corresponding to the target load within a short time, avoiding abnormal unit shutdowns. Furthermore, it can achieve islanded operation in the event of grid disconnection and has the capability for rapid reconnection. Thus, the high- and low-level dual-shaft steam turbine generator set can avoid abnormal shutdowns under emergency conditions, reducing the impact of sudden shutdowns on the power grid, greatly improving the safety, reliability, and economy of this type of unit, adapting to the innovation of coal-fired power generation technology, and possessing strong practical significance.

Description

Technical Field

[0001] This invention relates to the field of steam turbine generator technology, and in particular to a load reduction control method, system, equipment and medium for a dual-shaft steam turbine generator set. Background Technology

[0002] To build a clean, low-carbon, safe, and efficient energy system, the realization of a new type of large-capacity coal-fired power generating unit employing a dual-shaft, high-low arrangement technology can significantly reduce the length of main steam and reheat steam pipelines, thereby reducing investment, pressure drop, and temperature drop losses. Ultimately, this reduces heat consumption and improves unit performance, with heat consumption indicators leading the world's advanced levels. It can also significantly improve the efficiency of coal resource utilization, reducing flue gas pollution and carbon dioxide emissions at the source. This has a good demonstrative effect on promoting the development of the thermal power industry and advancing coal-fired power generation technology.

[0003] like Figure 1 As shown, in this type of unit, the high-level steam turbine generator is located above the boiler near the superheater outlet, while the low-level steam turbine generator is located on the conventional turbine hall operating floor. The selection of high- and low-level steam turbines and the cylinder configuration can be adjusted according to different design considerations. The superheated steam generated by the boiler enters the high-level steam turbine generator, and the exhaust steam after performing work is reheated twice before entering the low-level steam turbine generator. The two steam turbine generators are connected in series on the working fluid, and can also operate independently or be connected to the grid for power generation.

[0004] However, there is no existing experience to draw upon regarding how to ensure the stable operation of two turbine generators arranged in a high-low dual-shaft configuration under accident conditions such as boiler main auxiliary equipment tripping or turbine and generator failure. Therefore, it is necessary to develop a rapid load reduction control method for this type of new unit, which can prevent abnormal shutdown of the unit under accident conditions by switching the unit load back. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the defect that conventional auxiliary machine failure load reduction schemes in the prior art are not applicable to high and low position dual-shaft steam turbine generator sets, and to provide a load reduction control method, system, equipment and medium for dual-shaft steam turbine generator sets.

[0006] The present invention solves the above-mentioned technical problems through the following technical solution:

[0007] A load reduction control method for a dual-shaft steam turbine generator set, the dual-shaft steam turbine generator set including a low-level steam turbine generator and a high-level steam turbine generator, the load reduction control method comprising:

[0008] When any one of the following occurs—a boiler auxiliary machine trip, a fault in the high-level turbine generator, a fault in the low-level turbine generator, or the dual-shaft turbine generator set disconnecting from the grid—the boiler load is reduced, and the high-level turbine generator and the low-level turbine generator are controlled according to a preset procedure, so that the dual-shaft turbine generator set returns to a safe operating state.

[0009] Preferably, when the boiler auxiliary equipment trips, the step of triggering boiler load reduction and controlling the high-level steam turbine generator and the low-level steam turbine generator according to a preset procedure includes:

[0010] The dual-shaft steam turbine generator set is triggered to exit the coordinated mode and enter the turbine following mode;

[0011] The boiler main control enters manual control mode and reduces the boiler main control output to a first specified ratio of the unit's rated load according to a first preset rate, wherein the first specified ratio is a preset boiler main control command;

[0012] The high-level steam turbine generator enters the main steam pressure control mode and reduces the main steam pressure to a first pressure value according to a second preset rate. The first pressure value is determined according to a first pressure function and a first specified ratio.

[0013] The low-level steam turbine generator enters the secondary reheat pressure control mode and reduces the secondary reheat steam pressure to a second pressure value according to a third preset rate. The second pressure value is determined based on a second pressure function and the load of the low-level steam turbine generator after the boiler auxiliary machine trips.

[0014] The first specified ratio, the first preset rate, the second preset rate, and the third rate correspond to the boiler auxiliary equipment that tripped.

[0015] Preferably, when the high-level steam turbine generator trips, the step of triggering boiler load reduction and controlling the high-level steam turbine generator and the low-level steam turbine generator according to a preset procedure includes:

[0016] Trigger the dual-shaft steam turbine generator set to exit the coordination mode;

[0017] The boiler main control enters manual control mode. If the unit load of the dual-shaft turbine generator set is greater than the rated load of the unit by a first preset ratio before the high-level turbine generator trips, the boiler main control output is reduced to a second specified ratio according to a fourth preset rate. The second specified ratio is preset based on the rated power of the low-level turbine generator and the maximum flow rate of the low-pressure bypass. Otherwise, the boiler main control output remains unchanged.

[0018] The low-level steam turbine generator enters the load control mode, and the load setting value of the low-level steam turbine generator is the smaller value between the low-level rated load of the low-level steam turbine generator and the load determined according to the third load function and the secondary reheat steam pressure.

[0019] The high-pressure bypass opens quickly and enters the main steam pressure control mode after a second preset time. If the unit load of the dual-shaft turbine generator set is greater than a second preset proportion of the unit's rated load before the high-level turbine generator trips, the high-pressure bypass opens quickly throughout its entire stroke. Otherwise, the opening degree of the high-pressure bypass is determined based on the initial opening degree and the superimposed opening degree before the quick opening. The superimposed opening degree is determined based on a fourth opening degree function and the load of the high-level turbine generator within a first preset time before the quick opening. The set value of the main steam pressure is determined based on a first pressure function and a second specified proportion.

[0020] The intermediate pressure bypass opens quickly and enters the reheat steam pressure control mode after a second preset time. If the unit load of the dual-shaft turbine generator set is greater than a second preset ratio of the rated load of the unit before the high-level turbine generator trips, the intermediate pressure bypass opens quickly throughout its entire stroke. Otherwise, the opening degree of the intermediate pressure bypass is determined based on the initial opening degree and the superimposed opening degree before the quick opening. The superimposed opening degree is determined based on the fourth opening degree function and the load of the high-level turbine generator within a first preset time before the quick opening. The set value of the reheat steam pressure is determined based on the fifth pressure function and the second specified ratio.

[0021] The low-pressure bypass opens quickly and enters the secondary reheat steam pressure control mode after a second preset time. If the load of the low-pressure turbine generator is greater than a third preset ratio of the low-pressure rated load before the high-pressure turbine generator trips, the low-pressure bypass opens quickly throughout its entire stroke. Otherwise, the opening degree of the low-pressure bypass is determined based on the initial opening degree and the superimposed opening degree before the quick opening. The superimposed opening degree is determined based on the sixth opening degree function and the load of the low-pressure turbine generator within a first preset time before the quick opening. The set value of the secondary reheat steam pressure is determined based on the preset superimposed pressure, the second pressure function, and the load of the low-pressure turbine generator.

[0022] Preferably, when the high-level steam turbine generator is disconnected, the step of triggering boiler load reduction and controlling the high-level steam turbine generator and the low-level steam turbine generator according to a preset process includes:

[0023] Triggering the tripping of the high-level steam turbine generator and the exit of the coordinated mode of the dual-shaft steam turbine generator set;

[0024] The boiler main control enters manual control mode. If the unit load of the dual-shaft turbine generator set is greater than the rated load of the unit by a first preset ratio before the high-level turbine generator trips, the boiler main control output is reduced to a second specified ratio according to a fourth preset rate. The second specified ratio is preset based on the rated power of the low-level turbine generator and the maximum flow rate of the low-pressure bypass. Otherwise, the boiler main control output remains unchanged.

[0025] The low-level steam turbine generator enters the load control mode, and the load setting value of the low-level steam turbine generator is the smaller value between the low-level rated load of the low-level steam turbine generator and the load determined according to the third load function and the secondary reheat steam pressure.

[0026] The high-pressure bypass opens quickly and enters the main steam pressure control mode after a second preset time. If the unit load of the dual-shaft turbine generator set is greater than a second preset proportion of the unit's rated load before the high-level turbine generator trips, the high-pressure bypass opens quickly throughout its entire stroke. Otherwise, the opening degree of the high-pressure bypass is determined based on the initial opening degree and the superimposed opening degree before the quick opening. The superimposed opening degree is determined based on a fourth opening degree function and the load of the high-level turbine generator within a first preset time before the quick opening. The set value of the main steam pressure is determined based on a first pressure function and a second specified proportion.

[0027] The intermediate pressure bypass opens quickly and enters the reheat steam pressure control mode after a second preset time. If the unit load of the dual-shaft turbine generator set is greater than a second preset ratio of the rated load of the unit before the high-level turbine generator trips, the intermediate pressure bypass opens quickly throughout its entire stroke. Otherwise, the opening degree of the intermediate pressure bypass is determined based on the initial opening degree and the superimposed opening degree before the quick opening. The superimposed opening degree is determined based on the fourth opening degree function and the load of the high-level turbine generator within a first preset time before the quick opening. The set value of the reheat steam pressure is determined based on the fifth pressure function and the second specified ratio.

[0028] The low-pressure bypass opens quickly and enters the secondary reheat steam pressure control mode after a second preset time. If the load of the low-pressure turbine generator is greater than a third preset ratio of the low-pressure rated load before the high-pressure turbine generator trips, the low-pressure bypass opens quickly throughout its entire stroke. Otherwise, the opening degree of the low-pressure bypass is determined based on the initial opening degree and the superimposed opening degree before the quick opening. The superimposed opening degree is determined based on the sixth opening degree function and the load of the low-pressure turbine generator within a first preset time before the quick opening. The set value of the secondary reheat steam pressure is determined based on the preset superimposed pressure, the second pressure function, and the load of the low-pressure turbine generator.

[0029] Preferably, when the low-level turbine generator trips, the step of triggering the boiler to reduce load and controlling the high-level turbine generator and the low-level turbine generator according to a preset procedure includes:

[0030] Trigger the dual-shaft steam turbine generator set to exit the coordination mode;

[0031] The boiler main control system enters manual control mode, maintaining the boiler main control output unchanged.

[0032] The high-level steam turbine generator enters the main steam pressure control mode, and the set value of the main steam pressure is determined according to the seventh pressure function and the unit load of the dual-shaft steam turbine generator set.

[0033] The low-pressure bypass opens quickly and enters the secondary reheat steam pressure control mode after a second preset time. If the load of the low-level turbine generator is greater than the third preset ratio of the low-level rated load before the low-level turbine generator trips, the low-pressure bypass opens quickly throughout its entire stroke. Otherwise, the opening degree of the low-pressure bypass is determined based on the initial opening degree and the superimposed opening degree before the quick opening. The superimposed opening degree is determined based on the sixth opening degree function and the load of the low-level turbine generator within the first preset time before the quick opening. The set value of the secondary reheat steam pressure is the smaller of the first preset pressure value and the pressure value determined based on the eighth pressure function and the primary reheat steam pressure.

[0034] Preferably, when the low-level steam turbine generator is disconnected, the step of triggering boiler load reduction and controlling the high-level steam turbine generator and the low-level steam turbine generator according to a preset process includes:

[0035] Trigger the low-position steam turbine generator to enter the speed control mode and maintain the preset speed unchanged, and trigger the dual-shaft steam turbine generator set to exit the coordination mode;

[0036] The boiler main control system enters manual control mode, maintaining the boiler main control output unchanged.

[0037] The high-level steam turbine generator enters the main steam pressure control mode, and the set value of the main steam pressure is determined according to the seventh pressure function and the unit load of the dual-shaft steam turbine generator set.

[0038] The low-pressure bypass opens quickly and enters the secondary reheat steam pressure control mode after a second preset time. If the load of the low-level turbine generator is greater than the third preset ratio of the low-level rated load before the generator is disconnected, the low-pressure bypass opens quickly throughout its entire stroke. Otherwise, the opening degree of the low-pressure bypass is determined based on the initial opening degree and the superimposed opening degree before the quick opening. The superimposed opening degree is determined based on the sixth opening degree function and the load of the low-level turbine generator within the first preset time before the quick opening. The set value of the secondary reheat steam pressure is the smaller of the first preset pressure value and the pressure value determined based on the eighth pressure function and the primary reheat steam pressure.

[0039] Preferably, when the dual-shaft turbine generator set disconnects from the grid, the step of triggering boiler load reduction and controlling the high-level turbine generator and the low-level turbine generator according to a preset procedure includes:

[0040] The high-level steam turbine generator is triggered to trip, the low-level steam turbine generator enters speed control mode, and the dual-shaft steam turbine generator set exits the coordination mode.

[0041] The boiler main control enters manual control mode and reduces the boiler main control output to a third specified ratio of the unit's rated load according to the fifth preset rate. The third specified ratio is set by manually input boiler main control commands.

[0042] The high-pressure bypass opens quickly and enters the main steam pressure control mode after a second preset time. If the unit load of the dual-shaft turbine generator set is greater than a second preset proportion of the rated load of the unit before the high-level turbine generator trips, the high-pressure bypass opens quickly throughout its entire stroke. Otherwise, the opening degree of the high-pressure bypass is determined based on the initial opening degree and the superimposed opening degree before the quick opening. The superimposed opening degree is determined based on the fourth opening degree function and the load of the high-level turbine generator within a first preset time before the quick opening. The set value of the main steam pressure is determined based on the first pressure function and the third specified proportion.

[0043] The intermediate pressure bypass opens quickly and enters the reheat steam pressure control mode after a second preset time. If the unit load of the dual-shaft turbine generator set is greater than a second preset proportion of the unit's rated load before the high-level turbine generator trips, the intermediate pressure bypass opens quickly throughout its entire stroke. Otherwise, the opening degree of the intermediate pressure bypass is determined based on the initial opening degree and the superimposed opening degree before the quick opening. The superimposed opening degree is determined based on the fourth opening degree function and the load of the high-level turbine generator within a first preset time before the quick opening. The set value of the reheat steam pressure is determined based on the fifth pressure function and the third specified proportion.

[0044] The low-pressure bypass opens quickly and enters the secondary reheat steam pressure control mode after a second preset time. If the load of the low-level turbine generator is greater than a third preset ratio of the low-level rated load before entering the speed control mode, the low-pressure bypass opens quickly throughout its entire stroke. Otherwise, the opening degree of the low-pressure bypass is determined based on the initial opening degree and the superimposed opening degree before the quick opening. The superimposed opening degree is determined based on the sixth opening degree function and the load of the low-level turbine generator within a first preset time before the quick opening. The set value of the secondary reheat steam pressure is the smaller of the first preset pressure value and the pressure value determined based on the eighth pressure function and the primary reheat steam pressure.

[0045] A load reduction control system for a dual-shaft steam turbine generator set, comprising a low-level steam turbine generator and a high-level steam turbine generator, wherein the load reduction control system is used to trigger boiler load reduction when any one of the following occurs: boiler auxiliary equipment tripping, high-level steam turbine generator failure, low-level steam turbine generator failure, or the dual-shaft steam turbine generator set disconnecting from the grid; and to control the high-level steam turbine generator and the low-level steam turbine generator according to a preset process, so that the dual-shaft steam turbine generator set returns to a safe operating state.

[0046] An electronic device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement any of the above-described methods for load reduction control of a dual-shaft steam turbine generator set.

[0047] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the above-described load reduction control methods for a dual-shaft steam turbine generator set.

[0048] The positive and progressive effects of this invention are as follows: In the event of a boiler main auxiliary machine tripping, or separate failures of the high- and low-level turbines and their generators, or disconnection of the unit's main transformer from the busbar, this invention enables the boiler and remaining turbines to automatically and synchronously reduce load rapidly. The bypass system coordinates the control, allowing the main process parameters of the unit to smoothly decrease to the safe operating range corresponding to the target load within a short time, avoiding abnormal unit shutdowns. Furthermore, it can achieve islanded operation in the event of grid disconnection and has the capability for rapid reconnection. Thus, the high- and low-level dual-shaft turbine generator unit can avoid abnormal shutdowns under accident conditions, reducing the impact of sudden shutdowns on the power grid, greatly improving the safety, reliability, and economy of this type of unit, adapting to the innovation of coal-fired power generation technology, and possessing strong practical significance. Attached Figure Description

[0049] Figure 1 This is a schematic diagram of the structure of a dual-shaft steam turbine generator set in the prior art.

[0050] Figure 2 This is a flowchart of a load reduction control method for a dual-shaft steam turbine generator set according to Embodiment 1 of the present invention.

[0051] Figure 3 This is a schematic diagram of the structure of an electronic device according to Embodiment 3 of the present invention. Detailed Implementation

[0052] The present invention will be further illustrated by way of embodiments below, but the present invention is not limited to the scope of the embodiments described herein.

[0053] Example 1

[0054] This embodiment provides a load reduction control method for a dual-shaft steam turbine generator set, which includes a low-level steam turbine generator and a high-level steam turbine generator. For example, a load reduction control method can be adopted. Figure 1 The diagram shows the structure of a dual-shaft steam turbine generator set. However, it should be understood that the selection of high- and low-level steam turbine generators and the cylinder configuration can be adjusted according to different design considerations. Figure 1 The unit capacity, turbine selection, and cylinder configuration are not limitations of this invention.

[0055] This embodiment will be explained with reference to the parameters of a megawatt-class unit.

[0056] Figure 2 A flowchart of this embodiment is shown. (Refer to...) Figure 2 The load reduction control method in this embodiment includes:

[0057] S1. When any one of the following occurs: boiler auxiliary machine tripping, high-level turbine generator failure, low-level turbine generator failure, or the dual-shaft turbine generator set disconnecting from the grid, the boiler load is reduced, and the high-level turbine generator and the low-level turbine generator are controlled according to a preset process, so that the dual-shaft turbine generator set can return to a safe operating state.

[0058] In this embodiment, under the following accident conditions: the main auxiliary equipment of the boiler trips, or the high- and low-level turbine generators and their generators fail respectively, or the main transformer of the unit is disconnected from the bus, the boiler is automatically and quickly reduced in load. The remaining turbine generators and the bypass system work together to control the main process parameters of the unit, so that the main process parameters of the unit can be steadily reduced to the safe operating range corresponding to the target load in a short period of time.

[0059] Specifically, in this embodiment, when the boiler auxiliary equipment (e.g., forced draft fan, induced draft fan, or coal mill, etc.) trips, the auxiliary equipment RUNBACK is triggered. This triggers the boiler to reduce load, and controls the high-level turbine generator and the low-level turbine generator according to a preset process, including:

[0060] Step 111: Trigger the dual-shaft steam turbine generator set to exit the coordinated mode and enter the turbine following mode;

[0061] Step 112: The boiler main control enters the manual control mode and reduces the output of the boiler main control to a first specified ratio (e.g., 50%) of the rated load of the unit according to the first preset rate. The first specified ratio is a preset boiler main control command and corresponds to the equipment type of the boiler auxiliary machine that tripped.

[0062] Step 113: The high-level steam turbine generator enters the main steam pressure control mode and reduces the main steam pressure to a first pressure value according to the second preset rate. The first pressure value is determined according to the first pressure function F1(x) and the first specified ratio.

[0063] Step 114: The low-level steam turbine generator enters the secondary reheat pressure control mode and reduces the secondary reheat steam pressure to a second pressure value according to a third preset rate (e.g., 0.5 MPa / min). The second pressure value is determined based on the second pressure function F2(x) and the load of the low-level steam turbine generator after the boiler auxiliary machine trips.

[0064] In this embodiment, the high-level turbine generator reduces the main steam pressure to the pressure value corresponding to the preset target load of the unit according to the preset sliding pressure curve and sliding pressure rate. At the same time, the low-level turbine generator reduces the secondary reheat steam pressure to the pressure value corresponding to the preset target load of the unit according to the preset sliding pressure curve and sliding pressure rate. This ensures that the secondary reheat steam reheat user still has qualified steam to maintain the stable operation of the unit during the rapid load reduction process of the unit.

[0065] In this embodiment, the first specified ratio, the first preset rate, the second preset rate, and the third rate correspond to the boiler auxiliary machine that tripped. The first pressure function F1(x) and the second pressure function F2(x) can be customized according to actual applications.

[0066] For example, in this embodiment, the first pressure function F1(x) can be:

[0067] x-Boiler master control command (%) 0 30 40 50 75 90 100 110 y - Main steam pressure setting (MPa) 9 13 15.5 18.5 28 31 32.2 32.5

[0068] The second pressure function F2(x) can be:

[0069] x - Low-level generator load (MW) 0 210 300 375 563 750 780 800 y - Secondary reheat steam pressure setting (MPa) 0.83 0.83 1 1.22 1.77 2.29 2.37 2.45

[0070] Furthermore, in the event of a trip in the boiler auxiliary equipment, the high-pressure bypass, medium-pressure bypass, and low-pressure bypass of the steam turbine remain fully closed and do not participate in the operation.

[0071] In this embodiment, when the high-level turbine generator trips, the high-level turbine generator RUNBACK is triggered. The process of triggering boiler load reduction and controlling the high-level turbine generator and the low-level turbine generator according to a preset procedure includes:

[0072] Step 121: Trigger the dual-shaft steam turbine generator set to exit the coordination mode;

[0073] Step 122: The boiler main control enters manual control mode. If the unit load of the dual-shaft turbine generator set is greater than the first preset ratio (e.g., 65%) of the rated load of the unit before the high-level turbine generator trips, the boiler main control output is reduced to the second specified ratio (e.g., 65%, further reducing the air volume, coal volume, and feedwater volume to the amount corresponding to 65% of the boiler main control output) according to the fourth preset rate (e.g., 100% / min). The second specified ratio is preset based on the rated power of the low-level turbine generator and the maximum flow rate of the low-pressure bypass. Otherwise, the boiler main control output remains unchanged.

[0074] Step 123: The low-level steam turbine generator enters the load control mode. The load setting value of the low-level steam turbine generator is the smaller value between the low-level rated load of the low-level steam turbine generator and the load determined according to the third load function F3(x) and the secondary reheat steam pressure. This is to open the steam inlet regulating valve as wide as possible without exceeding the rated load of the low-level generator, so as to maximize the absorption of secondary reheat steam and ensure that the low-level steam turbine generator continues to operate at high load while ensuring that the secondary reheat steam pressure is not lower than the lower limit pressure required by its regenerative system, and that there is still qualified steam to maintain the stable operation of the unit.

[0075] Step 124: The high-pressure bypass is opened quickly and enters the main steam pressure control mode after a second preset time (e.g., 3s). If the unit load of the dual-shaft turbine generator set is greater than a second preset proportion (e.g., 65%) of the rated load of the unit before the high-level turbine generator trips, the high-pressure bypass is opened quickly throughout its entire stroke (e.g., through a quick-opening solenoid valve). Otherwise, the opening degree of the high-pressure bypass is determined based on the initial opening degree and the superimposed opening degree before the quick opening. The superimposed opening degree is determined based on the fourth opening degree function F4(x) and the load of the high-level turbine generator within a first preset time (e.g., 2s) before the quick opening. The set value of the main steam pressure is determined based on the first pressure function F1(x) and the second specified proportion.

[0076] Step 125: The medium-pressure bypass is opened quickly and enters the reheat steam pressure control mode after the second preset time of the quick opening. If the unit load of the dual-shaft turbine generator set is greater than the second preset ratio of the rated load of the unit before the high-level turbine generator trips, the medium-pressure bypass is opened quickly throughout its entire stroke. Otherwise, the opening degree of the medium-pressure bypass is determined according to the initial opening degree and the superimposed opening degree before the quick opening. The superimposed opening degree is determined according to the fourth opening degree function F4(x) and the load of the high-level turbine generator within the first preset time before the quick opening. The set value of the reheat steam pressure is determined according to the fifth pressure function F5(x) and the second specified ratio.

[0077] Step 126: The low-pressure bypass is opened quickly and enters the secondary reheat steam pressure control mode after a second preset time. If the load of the low-pressure turbine generator is greater than the third preset ratio (e.g., 70%) of the low-pressure rated load before the high-pressure turbine generator trips, the low-pressure bypass is opened quickly throughout its entire stroke. Otherwise, the opening degree of the low-pressure bypass is determined based on the initial opening degree and the superimposed opening degree before the quick opening. The superimposed opening degree is determined based on the sixth opening degree function F6(x) and the load of the low-pressure turbine generator within the first preset time before the quick opening. The set value of the secondary reheat steam pressure is determined based on the preset superimposed pressure (e.g., 0.3MPa), the second pressure function F2(x), and the load of the low-pressure turbine generator.

[0078] In this embodiment, the high-pressure bypass, intermediate-pressure bypass, and low-pressure bypass of the steam turbine open instantaneously. After the high-pressure and intermediate-pressure bypasses open quickly, the system switches to the main steam pressure and reheat steam pressure control mode, with the pressure setpoints being the main steam pressure and reheat steam pressure values ​​corresponding to the current boiler main control output. After the low-pressure bypass opens quickly, the system switches to the overflow mode to control the secondary reheat steam pressure. Its pressure setpoint is based on the low-level turbine pressure setpoint function plus a certain amount of additive weight. After the system stabilizes, the low-pressure bypass of the steam turbine will be completely closed.

[0079] In this embodiment, the first preset ratio, the fourth preset rate, the first preset time, the second preset time, the second preset ratio, the third preset ratio, and the preset superimposed pressure can be customized according to actual applications. The third load function F3(x), the fourth opening function F4(x), the fifth pressure function F5(x), and the sixth opening function F6(x) can also be customized according to actual applications.

[0080] For example, in this embodiment, the third load function F3(x) can be:

[0081] x - Secondary reheat steam pressure (MPa) 0 0.73 0.95 1.17 1.72 2.29 2.37 2.45 y-Low-level generator load setting (WM) 0 210 300 375 563 750 780 800

[0082] The fourth opening function F4(x) can be:

[0083] x - High-level generator load (%) 0 30 50 65 100 y-Bypass opening increment (%) 5 35 75 100 100

[0084] The fifth pressure function F5(x) can be:

[0085] x-Boiler master control command (%) 0 30 40 50 75 90 100 110 y - Primary reheat steam pressure setting (MPa) 2.7 2.7 3.6 4.5 6.7 9 9.4 9.6

[0086] The sixth degree function F6(x) can be:

[0087] x - Low-level generator load (%) 0 30 50 70 100 y - Low lateral opening stacking amount (%) 5 50 100 100 100

[0088] In this embodiment, when the high-level steam turbine generator is disconnected, triggering the high-level steam turbine generator to RUNBACK triggers the boiler to reduce load, and controlling the high-level steam turbine generator and the low-level steam turbine generator according to a preset process includes: triggering the high-level steam turbine generator to trip and steps 121-126.

[0089] In this embodiment, when the high-level turbine generator malfunctions (including tripping, disconnection, etc.), while reducing the boiler heat load, steam is directed to the reheater and secondary reheater by adjusting the high-pressure bypass and intermediate-pressure bypass of the turbine. The low-level turbine generator switches to "load control" mode to ensure that it continues to operate at high load. While ensuring that the low-level turbine generator continues to operate at high load, it also ensures that the secondary reheat steam regeneration users still have qualified steam to maintain stable unit operation during the accident.

[0090] In this embodiment, when the low-level turbine generator trips, the low-level turbine generator RUNBACK is triggered. The process of triggering boiler load reduction and controlling the high-level turbine generator and the low-level turbine generator according to a preset procedure includes:

[0091] Step 131: Trigger the dual-shaft steam turbine generator set to exit the coordination mode;

[0092] Step 132: The boiler main control enters manual control mode, keeping the boiler main control output unchanged;

[0093] Step 133: The high-level steam turbine generator enters the main steam pressure control mode. The set value of the main steam pressure is determined according to the seventh pressure function F7(x) and the unit load of the dual-shaft steam turbine generator set.

[0094] Step 134: The low-pressure bypass is opened quickly and enters the secondary reheat steam pressure control mode after a second preset time. If the load of the low-level turbine generator is greater than the third preset ratio of the low-level rated load before the low-level turbine generator trips, the low-pressure bypass is opened quickly throughout its entire stroke. Otherwise, the opening degree of the low-pressure bypass is determined based on the initial opening degree and the superimposed opening degree before the quick opening. The superimposed opening degree is determined based on the sixth opening degree function F6(x) and the load of the low-level turbine generator within the first preset time before the quick opening. The set value of the secondary reheat steam pressure is the smaller of the first preset pressure value (e.g., 1.13 MPa) and the pressure value determined based on the eighth pressure function F8(x) and the primary reheat steam pressure.

[0095] In this embodiment, the first preset pressure value, the seventh pressure function F7(x), and the eighth pressure function F8(x) can be customized according to the actual application.

[0096] For example, in this embodiment, the seventh pressure function F7(x) can be:

[0097] x - Unit load (MW) 0 400 540 675 1000 1200 1350 1400 y - Main steam pressure setting (MPa) 9 13 15.5 18.5 28 31 32.2 32.5

[0098] The eighth pressure function F8(x) can be:

[0099] x - Primary reheat steam pressure (MPa) 0 2.7 3.6 4.5 6.7 9 9.4 9.6 y - Secondary reheat steam pressure setting (MPa) 0.83 0.83 1 1.22 1.77 2.29 2.37 2.45

[0100] In this embodiment, when the low-level turbine generator trips, the high-pressure bypass and intermediate-pressure bypass of the turbine remain fully closed and do not participate in the operation. The following steps involving secondary reheat steam recuperation users may also be included:

[0101] The auxiliary steam pressure reducing valve from the secondary reheat cold section automatically engages pressure control, with its setpoint switching from 0.05 MPa / min to 1 MPa to ensure stable pressure in the auxiliary steam header. The deaerator pressure regulating valve from the secondary reheat cold section automatically engages pressure control and opens to 70% for two seconds to ensure stable deaerator pressure. The feedwater pump steam source pressure regulating valve from the auxiliary steam header is set to automatic, with its pressure setpoint matching the setpoint of the feedwater pump steam source pressure regulating valve from the fourth-stage extraction steam, preventing stall of the steam-driven feedwater pump in case of loss of fourth-stage extraction steam and ensuring stable feedwater pump speed.

[0102] In this embodiment, when the low-level turbine generator is disconnected, the low-level turbine generator RUNBACK is triggered. The triggering of boiler load reduction and the control of the high-level turbine generator and the low-level turbine generator according to a preset process include:

[0103] The steps 131-134 involve the secondary reheat steam regeneration user, including triggering the low-level steam turbine generator to enter the speed control mode and maintaining a preset speed (e.g., 3000 rpm).

[0104] In this embodiment, when the low-level turbine generator fails (including tripping, disconnection, etc.), the turbine low-pressure bypass is adjusted to ensure that the secondary reheat steam regeneration user still has qualified steam to maintain the stable operation of the unit during the accident.

[0105] In this embodiment, when the dual-shaft turbine generator set disconnects from the grid (e.g., when the main transformer of the dual-shaft turbine generator set disconnects from the bus), the FCB is triggered. The triggering of boiler load reduction and the control of the high-level turbine generator and the low-level turbine generator according to a preset process include:

[0106] Triggering the high-level turbine generator trips (e.g., the high-level turbine generator ETS circuit trips when the grid connection signal disappears), the low-level turbine generator enters a speed control mode (e.g., a speed control mode that maintains a speed of 3000 rpm is triggered when the grid connection signal disappears, while operating with plant power), and the dual-shaft turbine generator set exits the coordination mode.

[0107] The boiler main control enters manual control mode and reduces the boiler main control output to the third specified ratio (45%) of the unit's rated load according to the fifth preset rate (e.g., 200% / min). The third specified ratio is set by the manually input boiler main control command.

[0108] In addition, the control steps for the high-pressure bypass can refer to step 124, the control steps for the medium-pressure bypass can refer to step 125, the control steps for the low-pressure bypass can refer to step 134, and the control steps for the secondary reheat steam regeneration user can refer to the steps corresponding to the tripping of the low-level turbine generator.

[0109] In this embodiment, after the main transformer of the unit is disconnected from the bus, the unit triggers the FCB (Fuel Circuit Breaker), and the boiler main control reduces the boiler main control output to a preset value at a preset rate. Simultaneously, the high-level turbine generator automatically trips, and the low-level turbine generator switches to "speed control" mode, maintaining operation at 3000 rpm with plant auxiliary power. The high-pressure, medium-pressure, and low-pressure bypasses of the turbine open instantly. After the high-pressure and medium-pressure bypasses open quickly, the system switches to the main steam pressure and reheat steam pressure control mode, and the pressure setpoints decrease at a preset rate to the main steam pressure and reheat steam pressure values ​​corresponding to the target boiler main control output. After the low-pressure bypass opens quickly, the system switches to the secondary reheat steam pressure control mode, with the setpoint being the smaller value of the function corresponding to the lowest pressure setpoint and the primary reheat steam pressure. Simultaneously, the steam-driven feedwater pump, deaerator, auxiliary steam header, etc., switch to the standby steam source.

[0110] This invention enables the boiler and remaining turbines to automatically and synchronously reduce load rapidly under accident conditions such as boiler main auxiliary equipment tripping, high- and low-level turbines and their generators failing separately, or the main transformer of the unit disconnecting from the bus. The bypass system coordinates the control, allowing the main process parameters of the unit to smoothly decrease to the safe operating range corresponding to the target load within a short time, avoiding abnormal unit shutdown. Furthermore, it can achieve islanded operation in the event of grid disconnection and has the capability for rapid reconnection. Thus, the high- and low-level dual-shaft turbine generator unit can avoid abnormal shutdown under accident conditions, reducing the impact of sudden shutdown on the power grid, greatly improving the safety, reliability, and economy of this type of unit, adapting to the innovation of coal-fired power generation technology, and has strong practical significance.

[0111] Example 2

[0112] This embodiment provides a load reduction control system for a dual-shaft steam turbine generator set. The dual-shaft steam turbine generator set includes a low-level steam turbine generator and a high-level steam turbine generator. For example, it can employ... Figure 1 The diagram shows the structure of a dual-shaft steam turbine generator set. However, it should be understood that the selection of high- and low-level steam turbine generators and the cylinder configuration can be adjusted according to different design considerations. Figure 1 The unit capacity, turbine selection, and cylinder configuration are not limitations of this invention.

[0113] This embodiment will be explained with reference to the parameters of a megawatt-class unit.

[0114] The load reduction control system of this embodiment is used to trigger boiler load reduction when any one of the following occurs: boiler auxiliary machine tripping, high-level turbine generator failure, low-level turbine generator failure, or the dual-shaft turbine generator set disconnecting from the grid. The system then controls the high-level turbine generator and the low-level turbine generator according to a preset process, so that the dual-shaft turbine generator set can return to a safe operating state.

[0115] Specifically, when the boiler auxiliary equipment trips, the load reduction control system of this embodiment is used to:

[0116] The dual-shaft steam turbine generator set is triggered to exit the coordinated mode and enter the turbine following mode;

[0117] The boiler main control enters manual control mode and reduces the boiler main control output to a first specified ratio of the unit's rated load according to a first preset rate. The first specified ratio is a preset boiler main control command and corresponds to the equipment type of the boiler auxiliary machine that tripped.

[0118] The high-level steam turbine generator enters the main steam pressure control mode and reduces the main steam pressure to a first pressure value according to a second preset rate. The first pressure value is determined according to a first pressure function and a first specified ratio.

[0119] The low-level steam turbine generator enters the secondary reheat pressure control mode and reduces the secondary reheat steam pressure to a second pressure value according to a third preset rate. The second pressure value is determined based on a second pressure function and the load of the low-level steam turbine generator after the boiler auxiliary machine trips.

[0120] The first specified ratio, the first preset rate, the second preset rate, and the third rate correspond to the boiler auxiliary equipment that tripped.

[0121] Specifically, when the high-level steam turbine generator trips, the load reduction control system of this embodiment is used for:

[0122] Trigger the dual-shaft steam turbine generator set to exit the coordination mode;

[0123] The boiler main control enters manual control mode. If the unit load of the dual-shaft turbine generator set is greater than the rated load of the unit by a first preset ratio before the high-level turbine generator trips, the boiler main control output is reduced to a second specified ratio according to a fourth preset rate. The second specified ratio is preset based on the rated power of the low-level turbine generator and the maximum flow rate of the low-pressure bypass. Otherwise, the boiler main control output remains unchanged.

[0124] The low-level steam turbine generator enters the load control mode, and the load setting value of the low-level steam turbine generator is the smaller value between the low-level rated load of the low-level steam turbine generator and the load determined according to the third load function and the secondary reheat steam pressure.

[0125] The high-pressure bypass opens quickly and enters the main steam pressure control mode after a second preset time. If the unit load of the dual-shaft turbine generator set is greater than a second preset proportion of the unit's rated load before the high-level turbine generator trips, the high-pressure bypass opens quickly throughout its entire stroke. Otherwise, the opening degree of the high-pressure bypass is determined based on the initial opening degree and the superimposed opening degree before the quick opening. The superimposed opening degree is determined based on a fourth opening degree function and the load of the high-level turbine generator within a first preset time before the quick opening. The set value of the main steam pressure is determined based on a first pressure function and a second specified proportion.

[0126] The intermediate pressure bypass opens quickly and enters the reheat steam pressure control mode after a second preset time. If the unit load of the dual-shaft turbine generator set is greater than a second preset ratio of the rated load of the unit before the high-level turbine generator trips, the intermediate pressure bypass opens quickly throughout its entire stroke. Otherwise, the opening degree of the intermediate pressure bypass is determined based on the initial opening degree and the superimposed opening degree before the quick opening. The superimposed opening degree is determined based on the fourth opening degree function and the load of the high-level turbine generator within a first preset time before the quick opening. The set value of the reheat steam pressure is determined based on the fifth pressure function and the second specified ratio.

[0127] The low-pressure bypass opens quickly and enters the secondary reheat steam pressure control mode after a second preset time. If the load of the low-pressure turbine generator is greater than a third preset ratio of the low-pressure rated load before the high-pressure turbine generator trips, the low-pressure bypass opens quickly throughout its entire stroke. Otherwise, the opening degree of the low-pressure bypass is determined based on the initial opening degree and the superimposed opening degree before the quick opening. The superimposed opening degree is determined based on the sixth opening degree function and the load of the low-pressure turbine generator within a first preset time before the quick opening. The set value of the secondary reheat steam pressure is determined based on the preset superimposed pressure, the second pressure function, and the load of the low-pressure turbine generator.

[0128] Specifically, when the high-level steam turbine generator is disconnected, the load reduction control system of this embodiment is used for:

[0129] Triggering the tripping of the high-level steam turbine generator and the exit of the coordinated mode of the dual-shaft steam turbine generator set;

[0130] The boiler main control enters manual control mode. If the unit load of the dual-shaft turbine generator set is greater than the rated load of the unit by a first preset ratio before the high-level turbine generator trips, the boiler main control output is reduced to a second specified ratio according to a fourth preset rate. The second specified ratio is preset by the rated power of the low-level turbine generator and the maximum flow rate of the low-pressure bypass. Otherwise, the boiler main control output remains unchanged.

[0131] The low-level steam turbine generator enters the load control mode, and the load setting value of the low-level steam turbine generator is the smaller value between the low-level rated load of the low-level steam turbine generator and the load determined according to the third load function and the secondary reheat steam pressure.

[0132] The high-pressure bypass opens quickly and enters the main steam pressure control mode after a second preset time. If the unit load of the dual-shaft turbine generator set is greater than a second preset proportion of the unit's rated load before the high-level turbine generator trips, the high-pressure bypass opens quickly throughout its entire stroke. Otherwise, the opening degree of the high-pressure bypass is determined based on the initial opening degree and the superimposed opening degree before the quick opening. The superimposed opening degree is determined based on a fourth opening degree function and the load of the high-level turbine generator within a first preset time before the quick opening. The set value of the main steam pressure is determined based on a first pressure function and a second specified proportion.

[0133] The intermediate pressure bypass opens quickly and enters the reheat steam pressure control mode after a second preset time. If the unit load of the dual-shaft turbine generator set is greater than a second preset ratio of the rated load of the unit before the high-level turbine generator trips, the intermediate pressure bypass opens quickly throughout its entire stroke. Otherwise, the opening degree of the intermediate pressure bypass is determined based on the initial opening degree and the superimposed opening degree before the quick opening. The superimposed opening degree is determined based on the fourth opening degree function and the load of the high-level turbine generator within a first preset time before the quick opening. The set value of the reheat steam pressure is determined based on the fifth pressure function and the second specified ratio.

[0134] The low-pressure bypass opens quickly and enters the secondary reheat steam pressure control mode after a second preset time. If the load of the low-pressure turbine generator is greater than a third preset ratio of the low-pressure rated load before the high-pressure turbine generator trips, the low-pressure bypass opens quickly throughout its entire stroke. Otherwise, the opening degree of the low-pressure bypass is determined based on the initial opening degree and the superimposed opening degree before the quick opening. The superimposed opening degree is determined based on the sixth opening degree function and the load of the low-pressure turbine generator within a first preset time before the quick opening. The set value of the secondary reheat steam pressure is determined based on the preset superimposed pressure, the second pressure function, and the load of the low-pressure turbine generator.

[0135] Specifically, when the low-level turbine generator trips, the load reduction control system of this embodiment is used for:

[0136] Trigger the dual-shaft steam turbine generator set to exit the coordination mode;

[0137] The boiler main control system enters manual control mode, maintaining the boiler main control output unchanged.

[0138] The high-level steam turbine generator enters the main steam pressure control mode, and the set value of the main steam pressure is determined according to the seventh pressure function and the unit load of the dual-shaft steam turbine generator set.

[0139] The low-pressure bypass opens quickly and enters the secondary reheat steam pressure control mode after a second preset time. If the load of the low-level turbine generator is greater than the third preset ratio of the low-level rated load before the low-level turbine generator trips, the low-pressure bypass opens quickly throughout its entire stroke. Otherwise, the opening degree of the low-pressure bypass is determined based on the initial opening degree and the superimposed opening degree before the quick opening. The superimposed opening degree is determined based on the sixth opening degree function and the load of the low-level turbine generator within the first preset time before the quick opening. The set value of the secondary reheat steam pressure is the smaller of the first preset pressure value and the pressure value determined based on the eighth pressure function and the primary reheat steam pressure.

[0140] Specifically, when the low-level steam turbine generator is disconnected, the load reduction control system of this embodiment is used for:

[0141] Trigger the low-position steam turbine generator to enter the speed control mode and maintain the preset speed unchanged, and trigger the dual-shaft steam turbine generator set to exit the coordination mode;

[0142] The boiler main control system enters manual control mode, maintaining the boiler main control output unchanged.

[0143] The high-level steam turbine generator enters the main steam pressure control mode, and the set value of the main steam pressure is determined according to the seventh pressure function and the unit load of the dual-shaft steam turbine generator set.

[0144] The low-pressure bypass opens quickly and enters the secondary reheat steam pressure control mode after a second preset time. If the load of the low-level turbine generator is greater than the third preset ratio of the low-level rated load before the generator is disconnected, the low-pressure bypass opens quickly throughout its entire stroke. Otherwise, the opening degree of the low-pressure bypass is determined based on the initial opening degree and the superimposed opening degree before the quick opening. The superimposed opening degree is determined based on the sixth opening degree function and the load of the low-level turbine generator within the first preset time before the quick opening. The set value of the secondary reheat steam pressure is the smaller of the first preset pressure value and the pressure value determined based on the eighth pressure function and the primary reheat steam pressure.

[0145] Specifically, when the dual-shaft turbine generator set disconnects from the grid, the load reduction control system of this embodiment is used for:

[0146] The high-level steam turbine generator is triggered to trip, the low-level steam turbine generator enters speed control mode, and the dual-shaft steam turbine generator set exits the coordination mode.

[0147] The boiler main control enters manual control mode and reduces the boiler main control output to a third specified ratio of the unit's rated load according to the fifth preset rate. The third specified ratio is set by manually input boiler main control commands.

[0148] The high-pressure bypass opens quickly and enters the main steam pressure control mode after a second preset time. If the unit load of the dual-shaft turbine generator set is greater than a second preset proportion of the rated load of the unit before the high-level turbine generator trips, the high-pressure bypass opens quickly throughout its entire stroke. Otherwise, the opening degree of the high-pressure bypass is determined based on the initial opening degree and the superimposed opening degree before the quick opening. The superimposed opening degree is determined based on the fourth opening degree function and the load of the high-level turbine generator within a first preset time before the quick opening. The set value of the main steam pressure is determined based on the first pressure function and the third specified proportion.

[0149] The intermediate pressure bypass opens quickly and enters the reheat steam pressure control mode after a second preset time. If the unit load of the dual-shaft turbine generator set is greater than a second preset proportion of the unit's rated load before the high-level turbine generator trips, the intermediate pressure bypass opens quickly throughout its entire stroke. Otherwise, the opening degree of the intermediate pressure bypass is determined based on the initial opening degree and the superimposed opening degree before the quick opening. The superimposed opening degree is determined based on the fourth opening degree function and the load of the high-level turbine generator within a first preset time before the quick opening. The set value of the reheat steam pressure is determined based on the fifth pressure function and the third specified proportion.

[0150] The low-pressure bypass opens quickly and enters the secondary reheat steam pressure control mode after a second preset time. If the load of the low-level turbine generator is greater than a third preset ratio of the low-level rated load before entering the speed control mode, the low-pressure bypass opens quickly throughout its entire stroke. Otherwise, the opening degree of the low-pressure bypass is determined based on the initial opening degree and the superimposed opening degree before the quick opening. The superimposed opening degree is determined based on the sixth opening degree function and the load of the low-level turbine generator within a first preset time before the quick opening. The set value of the secondary reheat steam pressure is the smaller of the first preset pressure value and the pressure value determined based on the eighth pressure function and the primary reheat steam pressure.

[0151] The load reduction control system in this embodiment serves the same function as the load reduction control method in Embodiment 1, and will not be described again here.

[0152] Example 3

[0153] This embodiment provides an electronic device, which can be represented in the form of a computing device (e.g., a server), including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, it can implement the load reduction control method for the dual-shaft steam turbine generator set provided in Embodiment 1.

[0154] Figure 3 A schematic diagram of the hardware structure of this embodiment is shown, as follows: Figure 3 As shown, electronic device 9 specifically includes:

[0155] At least one processor 91, at least one memory 92, and a bus 93 for connecting different system components (including processor 91 and memory 92), wherein:

[0156] Bus 93 includes a data bus, an address bus, and a control bus.

[0157] The memory 92 includes volatile memory, such as random access memory (RAM) 921 and / or cache memory 922, and may further include read-only memory (ROM) 923.

[0158] The memory 92 also includes a program / utility 925 having a set (at least one) of program modules 924, including but not limited to: an operating system, one or more application programs, other program modules, and program data, each or some combination of these examples may include an implementation of a network environment.

[0159] The processor 91 executes various functional applications and data processing by running computer programs stored in the memory 92, such as the load reduction control method for a dual-shaft steam turbine generator set provided in Embodiment 1 of the present invention.

[0160] Electronic device 9 can further communicate with one or more external devices 94 (e.g., keyboard, pointing device, etc.). This communication can be performed via input / output (I / O) interface 95. Furthermore, electronic device 9 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public network, such as the Internet) via network adapter 96. Network adapter 96 communicates with other modules of electronic device 9 via bus 93. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with electronic device 9, including but not limited to: microcode, device drivers, redundant processors, external disk drive arrays, RAID (disk array) systems, tape drives, and data backup storage systems, etc.

[0161] It should be noted that although several units / modules or sub-units / modules of the electronic device have been mentioned in the detailed description above, this division is merely exemplary and not mandatory. In fact, according to the embodiments of this application, the features and functions of two or more units / modules described above can be embodied in one unit / module. Conversely, the features and functions of one unit / module described above can be further divided and embodied by multiple units / modules.

[0162] Example 4

[0163] This embodiment provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the load reduction control method for a dual-shaft steam turbine generator set provided in Embodiment 1.

[0164] The readable storage medium may be more specifically adopted, including but not limited to: portable disk, hard disk, random access memory, read-only memory, erasable programmable read-only memory, optical storage device, magnetic storage device, or any suitable combination thereof.

[0165] In a possible implementation, the present invention can also be implemented as a program product comprising program code, which, when the program product is run on a terminal device, is used to cause the terminal device to perform the steps of implementing the load reduction control method for the dual-shaft steam turbine generator set described in Embodiment 1.

[0166] The program code for executing the present invention can be written in any combination of one or more programming languages. The program code can be executed entirely on the user device, partially on the user device, as a standalone software package, partially on the user device and partially on a remote device, or entirely on a remote device.

[0167] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A method of controlling load reduction of a two-shaft turbogenerator unit, characterized by, The double-shaft turbo-generator unit comprises a low-position turbo-generator and a high-position turbo-generator, and the load reduction control method comprises: When any one of boiler auxiliary tripping, high-position turbo-generator fault, low-position turbo-generator fault and double-shaft turbo-generator unit off-grid occurs, triggering boiler load reduction, and controlling the high-position turbo-generator and the low-position turbo-generator according to a preset process, so that the double-shaft turbo-generator unit re-enters a safe operation state; When the boiler auxiliary tripping occurs, the triggering boiler load reduction and controlling the high-position turbo-generator and the low-position turbo-generator according to a preset process comprises: Triggering the double-shaft turbo-generator unit to exit the coordinated mode and enter the turbine following mode; The boiler master control enters a manual control mode, and the boiler master control output is reduced to a first specified proportion of the unit rated load according to a first preset rate, wherein the first specified proportion is a preset boiler master control instruction; The high-position turbo-generator enters a main steam pressure control mode, and the main steam pressure is reduced to a first pressure value according to a second preset rate, wherein the first pressure value is determined according to a first pressure function and the first specified proportion; The low-position turbo-generator enters a secondary reheat pressure control mode, and the secondary reheat steam pressure is reduced to a second pressure value according to a third preset rate, wherein the second pressure value is determined according to a second pressure function and the load of the low-position turbo-generator after the boiler auxiliary tripping occurs; Wherein, the first specified proportion, the first preset rate, the second preset rate and the third rate have a corresponding relationship with the tripped boiler auxiliary; The high-position turbo-generator fault comprises tripping, and when the high-position turbo-generator tripping occurs, the triggering boiler load reduction and controlling the high-position turbo-generator and the low-position turbo-generator according to a preset process comprises: Triggering the double-shaft turbo-generator unit to exit the coordinated mode; The boiler master control enters a manual control mode, wherein if the unit load of the double-shaft turbo-generator unit before the high-position turbo-generator tripping occurs is greater than a first preset proportion of the unit rated load, the boiler master control output is reduced to a second specified proportion according to a fourth preset rate, and the second specified proportion is preset according to the rated power generation of the low-position turbo-generator and the maximum flow of the low-pressure bypass, otherwise, the boiler master control output remains unchanged; The low-position turbo-generator enters a load control mode, and the load set value of the low-position turbo-generator is the smaller one of the low-position rated load of the low-position turbo-generator and the load determined according to a third load function and the secondary reheat steam pressure; The high-pressure bypass is quickly opened and enters a main steam pressure control mode after a second preset time of quick opening, wherein if the unit load of the double-shaft turbo-generator unit is greater than a second preset proportion of the rated load of the unit before the high-level turbo-generator trips, the high-pressure bypass is fully opened, otherwise, the opening degree of the high-pressure bypass is determined according to an initial opening degree before quick opening and a superimposed opening degree, the superimposed opening degree is determined according to a fourth opening degree function and the load of the high-level turbo-generator in a first preset time before quick opening, and the set value of the main steam pressure is determined according to a first pressure function and the second specified proportion; The medium-pressure bypass is quickly opened and enters a primary reheated steam pressure control mode after a second preset time of quick opening, wherein if the unit load of the double-shaft turbo-generator unit is greater than a second preset proportion of the rated load of the unit before the high-level turbo-generator trips, the medium-pressure bypass is fully opened, otherwise, the opening degree of the medium-pressure bypass is determined according to an initial opening degree before quick opening and a superimposed opening degree, the superimposed opening degree is determined according to a fourth opening degree function and the load of the high-level turbo-generator in a first preset time before quick opening, and the set value of the primary reheated steam pressure is determined according to a fifth pressure function and the second specified proportion; The low-pressure bypass is quickly opened and enters a secondary reheated steam pressure control mode after a second preset time of quick opening, wherein if the load of the low-level turbo-generator is greater than a third preset proportion of the rated load of the low-level turbo-generator before the low-level turbo-generator trips, the low-pressure bypass is fully opened, otherwise, the opening degree of the low-pressure bypass is determined according to an initial opening degree before quick opening and a superimposed opening degree, the superimposed opening degree is determined according to a sixth opening degree function and the load of the low-level turbo-generator in a first preset time before quick opening, and the set value of the secondary reheated steam pressure is determined according to a preset superimposed pressure, a second pressure function and the load of the low-level turbo-generator; The low-level turbo-generator fault includes tripping, when the low-level turbo-generator trips, the boiler load reduction is triggered, and the high-level turbo-generator and the low-level turbo-generator are controlled according to a preset flow; The double-shaft turbo-generator unit is triggered to exit the coordinated mode; The boiler master control enters a manual control mode, and the boiler master control output is kept unchanged; The high-level turbo-generator enters a main steam pressure control mode, and the set value of the main steam pressure is determined according to a seventh pressure function and the unit load of the double-shaft turbo-generator unit; The low-pressure bypass is quickly opened and enters a secondary reheated steam pressure control mode after a second preset time of quick opening, wherein if the load of the low-level turbo-generator is greater than a third preset proportion of the rated load of the low-level turbo-generator before the low-level turbo-generator trips, the low-pressure bypass is fully opened, otherwise, the opening degree of the low-pressure bypass is determined according to an initial opening degree before quick opening and a superimposed opening degree, the superimposed opening degree is determined according to a sixth opening degree function and the load of the low-level turbo-generator in a first preset time before quick opening, and the set value of the secondary reheated steam pressure is the smaller one of a first preset pressure value and a pressure value determined according to an eighth pressure function and the primary reheated steam pressure; When the dual-shaft turbo-generator unit is off-grid, the trigger boiler reduces load, and controls the high-position turbo-generator and the low-position turbo-generator according to a preset flow includes: triggering the high-position turbo-generator to trip, the low-position turbo-generator to enter a speed control mode, and the dual-shaft turbo-generator unit to exit a coordinated mode; the boiler master control enters a manual control mode, and reduces the boiler master control output to a third specified proportion of the unit rated load according to a fifth preset speed, wherein the third specified proportion is set by a manually input boiler master control instruction; the high-pressure bypass is quickly opened, and enters a main steam pressure control mode after a quick opening second preset time, wherein if the unit load of the dual-shaft turbo-generator unit before the high-position turbo-generator trips is greater than a second preset proportion of the unit rated load, the high-pressure bypass is fully opened, otherwise, the quick opening degree of the high-pressure bypass is determined according to an initial opening degree before quick opening and a superimposed opening degree, the superimposed opening degree is determined according to a fourth opening degree function and the load of the high-position turbo-generator in a first preset time before quick opening, and the set value of the main steam pressure is determined according to a first pressure function and the third specified proportion; the medium-pressure bypass is quickly opened, and enters a primary reheated steam pressure control mode after a quick opening second preset time, wherein if the unit load of the dual-shaft turbo-generator unit before the high-position turbo-generator trips is greater than a second preset proportion of the unit rated load, the medium-pressure bypass is fully opened, otherwise, the quick opening degree of the medium-pressure bypass is determined according to an initial opening degree before quick opening and a superimposed opening degree, the superimposed opening degree is determined according to a fourth opening degree function and the load of the high-position turbo-generator in a first preset time before quick opening, and the set value of the primary reheated steam pressure is determined according to a fifth pressure function and the third specified proportion; the low-pressure bypass is quickly opened, and enters a secondary reheated steam pressure control mode after a quick opening second preset time, wherein if the load of the low-position turbo-generator before the low-position turbo-generator enters the speed control mode is greater than a third preset proportion of the low-position rated load, the low-pressure bypass is fully opened, otherwise, the quick opening degree of the low-pressure bypass is determined according to an initial opening degree before quick opening and a superimposed opening degree, the superimposed opening degree is determined according to a sixth opening degree function and the load of the low-position turbo-generator in a first preset time before quick opening, and the set value of the secondary reheated steam pressure is the smaller one of a first preset pressure value and a pressure value determined according to an eighth pressure function and the primary reheated steam pressure.

2. The load-reduction control method of a two-shaft turbo-generator unit according to claim 1, characterized by, The high-position turbo-generator fault also includes splitting, when the high-position turbo-generator splits, the trigger boiler reduces load, and controls the high-position turbo-generator and the low-position turbo-generator according to a preset flow includes: triggering the high-position turbo-generator to trip and the dual-shaft turbo-generator unit to exit a coordinated mode; the boiler master enters a manual control mode, wherein, if the unit load of the dual-shaft turbo-generator unit is greater than a first preset proportion of the rated load of the unit before the high-pressure turbo-generator trips, the boiler master output is reduced to a second specified proportion according to a fourth preset rate, the second specified proportion being preset according to the rated power generation of the low-pressure turbo-generator and the maximum flow of the low-pressure bypass, otherwise, the boiler master output remains unchanged; the low-pressure turbo-generator enters a load control mode, the load set value of the low-pressure turbo-generator being the smaller of the low-pressure rated load of the low-pressure turbo-generator and the load determined according to a third load function and the secondary reheat steam pressure; the high-pressure bypass is quickly opened and enters a main steam pressure control mode after a second preset time of quick opening, wherein, if the unit load of the dual-shaft turbo-generator unit is greater than a second preset proportion of the rated load of the unit before the high-pressure turbo-generator trips, the high-pressure bypass is fully opened, otherwise, the quick opening degree of the high-pressure bypass is determined according to an initial opening degree before quick opening and a superimposed opening degree, the superimposed opening degree being determined according to a fourth opening degree function and the load of the high-pressure turbo-generator in a first preset time before quick opening, and the set value of the main steam pressure being determined according to a first pressure function and the second specified proportion; the medium-pressure bypass is quickly opened and enters a primary reheat steam pressure control mode after a second preset time of quick opening, wherein, if the unit load of the dual-shaft turbo-generator unit is greater than a second preset proportion of the rated load of the unit before the high-pressure turbo-generator trips, the medium-pressure bypass is fully opened, otherwise, the quick opening degree of the medium-pressure bypass is determined according to an initial opening degree before quick opening and a superimposed opening degree, the superimposed opening degree being determined according to a fourth opening degree function and the load of the high-pressure turbo-generator in a first preset time before quick opening, and the set value of the primary reheat steam pressure being determined according to a fifth pressure function and the second specified proportion; the low-pressure bypass is quickly opened and enters a secondary reheat steam pressure control mode after a second preset time of quick opening, wherein, if the load of the low-pressure turbo-generator is greater than a third preset proportion of the low-pressure rated load before the high-pressure turbo-generator trips, the low-pressure bypass is fully opened, otherwise, the quick opening degree of the low-pressure bypass is determined according to an initial opening degree before quick opening and a superimposed opening degree, the superimposed opening degree being determined according to a sixth opening degree function and the load of the low-pressure turbo-generator in a first preset time before quick opening, and the set value of the secondary reheat steam pressure being determined according to a preset superimposed pressure, a second pressure function and the load of the low-pressure turbo-generator.

3. The load-reduction control method of a two-shaft turbo-generator unit according to Claim 1, characterized by, the low-pressure turbo-generator fault also includes a split, when the low-pressure turbo-generator occurs split, the boiler load reduction is triggered, and the high-pressure turbo-generator and the low-pressure turbo-generator are controlled according to a preset process, including: triggering the low-pressure turbo-generator to enter a speed control mode and keeping a preset speed unchanged, and the dual-shaft turbo-generator unit exits a coordinated mode; the boiler master enters a manual control mode, keeping the boiler master output unchanged; The high-position steam turbine generator enters a main steam pressure control mode, and a set value of the main steam pressure is determined according to a seventh pressure function and a unit load of the double-shaft steam turbine generator unit; The low-pressure bypass is quickly opened and enters a secondary reheat steam pressure control mode after a quick opening second preset time, wherein, if the load of the low-position steam turbine generator is greater than a third preset proportion of a low-position rated load before the low-position steam turbine generator is tripped, the low-pressure bypass is fully opened, otherwise, a quick opening degree of the low-pressure bypass is determined according to an initial opening degree before the quick opening and a superimposed opening degree, the superimposed opening degree is determined according to a sixth opening degree function and the load of the low-position steam turbine generator in a first preset time before the quick opening, and a set value of the secondary reheat steam pressure is the smaller one of a first preset pressure value and a pressure value determined according to an eighth pressure function and a primary reheat steam pressure.

4. A load-reduction control system for a two-shaft turbogenerator unit, characterized by The double-shaft steam turbine generator unit includes a low-position steam turbine generator and a high-position steam turbine generator; The load reduction control system is configured to trigger a boiler load reduction when any one of a boiler auxiliary machine tripping, the high-position steam turbine generator fault, the low-position steam turbine generator fault and the double-shaft steam turbine generator unit off-grid occurs, and control the high-position steam turbine generator and the low-position steam turbine generator according to a preset procedure, so that the double-shaft steam turbine generator unit reenters a safe operation state; When the boiler auxiliary machine trips, the load reduction control system is specifically configured to: trigger the double-shaft steam turbine generator unit to exit a coordinated mode and enter a steam turbine following mode; a boiler main control enters a manual control mode, and a boiler main control output is reduced to a first designated proportion of a unit rated load according to a first preset rate, wherein the first designated proportion is a preset boiler main control instruction; the high-position steam turbine generator enters a main steam pressure control mode, and the main steam pressure is reduced to a first pressure value according to a second preset rate, the first pressure value being determined according to a first pressure function and the first designated proportion; the low-position steam turbine generator enters a secondary reheat pressure control mode, and the secondary reheat steam pressure is reduced to a second pressure value according to a third preset rate, the second pressure value being determined according to a second pressure function and the load of the low-position steam turbine generator after the boiler auxiliary machine trips; wherein the first designated proportion, the first preset rate, the second preset rate and the third rate have a corresponding relationship with the boiler auxiliary machine that trips; the high-position steam turbine generator fault includes tripping, and when the high-position steam turbine generator trips, the load reduction control system is further specifically configured to: trigger the double-shaft steam turbine generator unit to exit the coordinated mode; the boiler main control enters the manual control mode, wherein, if the unit load of the double-shaft steam turbine generator unit is greater than a first preset proportion of the unit rated load before the high-position steam turbine generator trips, the boiler main control output is reduced to a second designated proportion according to a fourth preset rate, the second designated proportion being preset according to a rated power generation of the low-position steam turbine generator and a maximum flow of the low-pressure bypass, otherwise, the boiler main control output remains unchanged; The low-position steam turbine generator enters a load control mode, and a load set value of the low-position steam turbine generator is a smaller value between a low-position rated load of the low-position steam turbine generator and a load determined according to a third load function and a secondary reheat steam pressure; The high-pressure bypass is fast opened and enters a main steam pressure control mode after fast opening for a second preset time, wherein if a unit load of the dual-shaft steam turbine generator before the high-position steam turbine generator trips is greater than a second preset proportion of a rated load of the unit, the high-pressure bypass is fast opened full stroke, otherwise, a fast opening degree of the high-pressure bypass is determined according to an initial opening degree before fast opening and a superimposed opening degree, the superimposed opening degree is determined according to a fourth opening degree function and a load of the high-position steam turbine generator in a first preset time before fast opening, and a set value of the main steam pressure is determined according to a first pressure function and the second specified proportion; The medium-pressure bypass is fast opened and enters a primary reheat steam pressure control mode after fast opening for a second preset time, wherein if a unit load of the dual-shaft steam turbine generator before the high-position steam turbine generator trips is greater than a second preset proportion of a rated load of the unit, the medium-pressure bypass is fast opened full stroke, otherwise, a fast opening degree of the medium-pressure bypass is determined according to an initial opening degree before fast opening and a superimposed opening degree, the superimposed opening degree is determined according to a fourth opening degree function and a load of the high-position steam turbine generator in a first preset time before fast opening, and a set value of the primary reheat steam pressure is determined according to a fifth pressure function and the second specified proportion; The low-pressure bypass is fast opened and enters a secondary reheat steam pressure control mode after fast opening for a second preset time, wherein if a load of the low-position steam turbine generator before the high-position steam turbine generator trips is greater than a third preset proportion of a low-position rated load, the low-pressure bypass is fast opened full stroke, otherwise, a fast opening degree of the low-pressure bypass is determined according to an initial opening degree before fast opening and a superimposed opening degree, the superimposed opening degree is determined according to a sixth opening degree function and a load of the low-position steam turbine generator in a first preset time before fast opening, and a set value of the secondary reheat steam pressure is determined according to a preset superimposed pressure, a second pressure function and the load of the low-position steam turbine generator; The low-position steam turbine generator fault includes tripping, and the load reduction control system is further specifically used for: Triggering the dual-shaft steam turbine generator to exit a coordinated mode; The boiler main control enters a manual control mode, and a boiler main control output is kept unchanged; The high-position steam turbine generator enters a main steam pressure control mode, and a set value of the main steam pressure is determined according to a seventh pressure function and a unit load of the dual-shaft steam turbine generator; The low-pressure bypass is quickly opened, and enters a secondary reheat steam pressure control mode after being quickly opened for a second preset time, wherein if the load of the low-position turbo-generator before the low-position turbo-generator trips is greater than a third preset proportion of a low-position rated load, the low-pressure bypass is fully opened, otherwise, the opening degree of the low-pressure bypass is determined according to an initial opening degree before quick opening and a superimposed opening degree, the superimposed opening degree is determined according to a sixth opening degree function and the load of the low-position turbo-generator in a first preset time before quick opening, and the set value of the secondary reheat steam pressure is the smaller one of a first preset pressure value and a pressure value determined according to an eighth pressure function and the primary reheat steam pressure; When the dual-shaft turbo-generator unit is off the grid, the load reduction control system is further configured to: trigger the high-position turbo-generator to trip, the low-position turbo-generator to enter a speed control mode, and the dual-shaft turbo-generator unit to exit a coordinated mode; the boiler main control enters a manual control mode, and the boiler main control output is reduced to a third specified proportion of a unit rated load at a fifth preset rate, wherein the third specified proportion is set by a manually input boiler main control instruction; the high-pressure bypass is quickly opened, and enters a main steam pressure control mode after being quickly opened for a second preset time, wherein if the unit load of the dual-shaft turbo-generator unit before the high-position turbo-generator trips is greater than a second preset proportion of a unit rated load, the high-pressure bypass is fully opened, otherwise, the opening degree of the high-pressure bypass is determined according to an initial opening degree before quick opening and a superimposed opening degree, the superimposed opening degree is determined according to a fourth opening degree function and the load of the high-position turbo-generator in a first preset time before quick opening, and the set value of the main steam pressure is determined according to a first pressure function and the third specified proportion; the medium-pressure bypass is quickly opened, and enters a primary reheat steam pressure control mode after being quickly opened for a second preset time, wherein if the unit load of the dual-shaft turbo-generator unit before the high-position turbo-generator trips is greater than a second preset proportion of a unit rated load, the medium-pressure bypass is fully opened, otherwise, the opening degree of the medium-pressure bypass is determined according to an initial opening degree before quick opening and a superimposed opening degree, the superimposed opening degree is determined according to a fourth opening degree function and the load of the high-position turbo-generator in a first preset time before quick opening, and the set value of the primary reheat steam pressure is determined according to a fifth pressure function and the third specified proportion; the low-pressure bypass is quickly opened, and enters a secondary reheat steam pressure control mode after being quickly opened for a second preset time, wherein if the load of the low-position turbo-generator before the low-position turbo-generator enters the speed control mode is greater than a third preset proportion of a low-position rated load, the low-pressure bypass is fully opened, otherwise, the opening degree of the low-pressure bypass is determined according to an initial opening degree before quick opening and a superimposed opening degree, the superimposed opening degree is determined according to a sixth opening degree function and the load of the low-position turbo-generator in a first preset time before quick opening, and the set value of the secondary reheat steam pressure is the smaller one of a first preset pressure value and a pressure value determined according to an eighth pressure function and the primary reheat steam pressure.

5. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The computer program causes the processor to implement the load reduction control method of the dual-shaft turbo-generator unit according to any one of claims 1 to 3 when the computer program is executed.

6. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program causes the processor to implement the steps of the load reduction control method of the dual-shaft turbo-generator unit according to any one of claims 1 to 3 when the computer program is executed.

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