Coordinated control method and system for dual-shaft steam turbine generator set

Abstract

The present invention discloses a coordinated control method and system for a dual-shaft steam turbine generator set, wherein the dual-shaft steam turbine generator set includes a low-level steam turbine generator and a high-level steam turbine generator, and the coordinated control method includes: determining coordinated control parameters according to the unit load instruction, and the coordinated control parameters include the low-level generator load corresponding to the low-level steam turbine generator, the high-level generator load corresponding to the high-level steam turbine generator, the low-level steam inlet pressure setting corresponding to the low-level steam turbine generator, and the high-level steam inlet pressure setting corresponding to the high-level steam turbine generator. The present invention enables two steam turbine generators arranged in a high-low dual-shaft arrangement to be well dispatched by the power grid as a whole as a power generation unit, while meeting the requirements of the coordinated control system regulation quality and primary frequency regulation, greatly improving the safety and economy of such units, adapting to the innovation of coal-fired power generation technology, and having strong practical significance.

Description

Technical Field

[0001] The present invention relates to the field of control technology, and in particular to a coordinated control method and system for a dual-shaft steam turbine generator set. Background Art

[0002] In order to help achieve the goals of carbon peak and carbon neutrality and build a clean, low-carbon, safe and efficient energy system, a new large-capacity coal-fired power generation unit with dual-axis, high-low position layout technology can greatly reduce the length of the main steam and reheat steam pipelines, thereby reducing investment, reducing pressure drop and temperature drop losses, and ultimately reducing heat consumption and improving unit performance. The heat consumption index will lead the world's advanced level, greatly improve the efficiency of coal resource utilization, and reduce flue gas pollution and carbon dioxide emissions from the source. It has a good demonstration effect on promoting the development of the thermal power industry and advancing the advancement of coal-fired power generation technology.

[0003] like Figure 1 As shown in the figure, the high-level steam turbine generator of this type of unit is arranged on the upper part of the boiler near the superheater outlet, and the low-level steam turbine generator is arranged on the operating floor of the traditional steam engine room. The selection of high and low-level steam turbines and the configuration of cylinders 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 work enters the low-level steam turbine generator after secondary reheating. The two steam turbine generators are arranged in series in terms of working fluid, and can be operated independently and connected to the grid for power generation.

[0004] However, there is no ready-made experience to learn from for how to control two steam turbine generators in a high-low dual-shaft arrangement as a whole and accept grid dispatch. Therefore, it is necessary to develop a new load distribution control method for this type of unit, connect it to the existing coordinated control system, meet the requirements of regulation quality and primary frequency regulation, and adapt to the innovation of coal-fired power generation technology. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiency that the conventional coordinated control system in the prior art is not suitable for high-low dual-axis steam turbine generator sets, and to provide a coordinated control method and system for a dual-axis steam turbine generator set.

[0006] The present invention solves the above technical problems through the following technical solutions:

[0007] A coordinated control method for a dual-shaft steam turbine generator set, the dual-shaft steam turbine generator set comprising a low-position steam turbine generator and a high-position steam turbine generator, the coordinated control method comprising:

[0008] The coordinated control parameters are determined according to the unit load instruction, and the coordinated control parameters include the low-level generator load corresponding to the low-level steam turbine generator, the high-level generator load corresponding to the high-level steam turbine generator, the low-level steam inlet pressure setting corresponding to the low-level steam turbine generator, and the high-level steam inlet pressure setting corresponding to the high-level steam turbine generator.

[0009] Preferably, determining the coordinated control parameters according to the unit load instruction includes:

[0010] When the low-level steam turbine generator is in the load control mode and meets the selection entry conditions, the low-level steam turbine generator selects to enter the valve full-open operation mode;

[0011] When the low-position steam turbine generator is in the load control mode and meets the automatic entry conditions, the low-position steam turbine generator automatically enters the valve full-open operation mode;

[0012] When the low-level steam turbine generator is in a fully-open valve operation mode, the low-level generator load is determined according to the pressure of the exhaust steam of the high-level steam turbine generator after secondary reheating, and the low-level generator load does not exceed the low-level load threshold.

[0013] Preferably, the selection entry condition includes: the unit load instruction is greater than the rated load of the first preset ratio and the high-level generator load is greater than the high-level minimum load corresponding to the high-level steam turbine generator, and the low-level load threshold corresponding to the selection entry condition is determined according to the difference between the unit load instruction and the high-level minimum load;

[0014] and / or,

[0015] The automatic entry condition includes tripping or load shedding of the high-level steam turbine generator, and the low-level load threshold corresponding to the automatic entry condition is the low-level maximum load corresponding to the low-level steam turbine generator.

[0016] Preferably, the step of determining the coordinated control parameters according to the unit load instruction further includes:

[0017] When the low-level steam turbine generator bypass is opened, the low-level steam turbine generator automatically enters a load control mode;

[0018] and / or,

[0019] The coordinated control method further comprises:

[0020] When the low-level steam turbine generator is in load control mode and in manual setting mode, the low-level generator load is determined by manual input;

[0021] and / or,

[0022] The step of determining the coordinated control parameters according to the unit load instruction further includes:

[0023] The high-level generator load is determined according to the difference between the unit load instruction and the actual load of the low-level steam turbine generator.

[0024] Preferably, determining the coordinated control parameters according to the unit load instruction includes:

[0025] When the low-level steam turbine generator is in pressure control mode, the low-level steam inlet pressure setting is determined according to the low-level generator load and the correction amount, and the upper limit of the low-level steam inlet pressure setting is determined according to the last-stage cylinder steam inlet pressure of the high-level steam turbine generator.

[0026] Preferably, the correction amount is determined according to the weighted sum of the unit variable load overshoot, the primary frequency regulation action amount, the main steam pressure deviation and the load pullback amount of the high-level steam turbine generator and the unit load instruction;

[0027] and / or,

[0028] When the total valve position instruction of the high-level steam turbine is greater than a second preset ratio and the actual load of the unit is less than the unit load instruction, the correction amount is determined according to the difference between the actual load of the unit and the unit load instruction.

[0029] Preferably, the coordinated control method further includes:

[0030] When the bypass of the low-level steam turbine generator is fully closed, the low-level steam turbine generator automatically enters the pressure control mode;

[0031] and / or,

[0032] When the high-position steam turbine generator is started, the low-position steam turbine generator automatically enters a pressure control mode;

[0033] and / or,

[0034] When a trip or load shedding occurs to a non-low-position steam turbine generator or a non-high-position steam turbine generator, resulting in a load reduction due to an auxiliary machine failure, the low-position steam turbine generator automatically enters a pressure control mode.

[0035] A coordinated control system for a dual-shaft steam turbine generator set, the dual-shaft steam turbine generator set comprising a low-position steam turbine generator and a high-position steam turbine generator;

[0036] The coordinated control system is used to determine the coordinated control parameters according to the unit load instructions, and the coordinated control parameters include the low-level generator load corresponding to the low-level steam turbine generator, the high-level generator load corresponding to the high-level steam turbine generator, the low-level steam inlet pressure setting corresponding to the low-level steam turbine generator, and the high-level steam inlet pressure setting corresponding to the high-level steam turbine generator.

[0037] An electronic device comprises 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, any one of the above-mentioned coordinated control methods for a dual-shaft steam turbine generator set is implemented.

[0038] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of any of the above-mentioned coordinated control methods for a dual-shaft steam turbine generator set.

[0039] The positive progressive effect of the present invention is that the present invention enables two steam turbine generators in a high-low dual-axis arrangement to be well dispatched by the power grid as a whole power generation unit, while meeting the requirements of the coordinated control system regulation quality and primary frequency regulation, greatly improving the safety and economy of such units, adapting to the innovation of coal-fired power generation technology, and having strong practical significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a structural schematic diagram of a dual-shaft steam turbine generator set in the prior art.

[0041] Figure 2 Flow chart of a coordinated control method of a dual-shaft steam turbine generator set according to Embodiment 1 of the present invention.

[0042] Figure 3 Schematic diagram of the working principle of the coordinated control method of a dual-shaft steam turbine generator set according to Example 1 of the present invention.

[0043] Figure 4 Schematic diagram of the structure of an electronic device according to Embodiment 3 of the present invention. DETAILED DESCRIPTION

[0044] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples.

[0045] Example 1

[0046] This embodiment provides a coordinated control method for a dual-shaft steam turbine generator set, wherein the dual-shaft steam turbine generator set includes a low-position steam turbine generator and a high-position steam turbine generator. For example, Figure 1The structure of the dual-shaft steam turbine generator set is shown, but it should be understood that the selection of high and low position 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 the present invention.

[0047] This embodiment will be described with reference to the parameters of a million-kilowatt class unit.

[0048] Figure 2 A flowchart of this embodiment is shown, referring to Figure 2 , the coordinated control method of this embodiment includes:

[0049] S101. Determine coordinated control parameters according to unit load instructions.

[0050] Among them, the coordinated control parameters include the low-level generator load corresponding to the low-level steam turbine generator, the high-level generator load corresponding to the high-level steam turbine generator, the low-level steam inlet pressure setting corresponding to the low-level steam turbine generator, and the high-level steam inlet pressure setting corresponding to the high-level steam turbine generator.

[0051] In this embodiment, after the low-level steam turbine generator is connected to the grid, in the unit coordination mode, the operator can manually select the low-level steam turbine generator as load control mode or pressure control mode according to different usage requirements. At the same time, the triggering of specific conditions can also cause the low-level steam turbine generator to automatically enter the load control mode or pressure control mode, thereby realizing automatic conversion between the two modes. Among them, the load control mode can be divided into manual setting mode and valve full-open operation mode.

[0052] Specifically, when the low-level steam turbine generator meets the first condition, the low-level steam turbine generator automatically enters the load control mode. In this embodiment, the first condition can be customized according to the actual application. For example, in this embodiment, the first condition can be implemented as the low-level steam turbine generator bypass is opened, that is, when the low-level steam turbine generator bypass is opened, the low-level steam turbine generator automatically enters the load control mode.

[0053] In this embodiment, step S101 may include:

[0054] When the low-level steam turbine generator is in load control mode and in manual setting mode, the low-level generator load is determined by manual input.

[0055] Specifically, in this embodiment, when the low-level steam turbine generator is in the manual setting mode, the operator can set the required low-level generator load according to actual application.

[0056] Furthermore, in this embodiment, step S101 may also include:

[0057] When the low-level steam turbine generator is in load control mode and meets the selection entry conditions, the low-level steam turbine generator selects to enter the valve full-open operation mode;

[0058] When the low-level steam turbine generator is in load control mode and meets the automatic entry conditions, the low-level steam turbine generator automatically enters the valve full-open operation mode;

[0059] When the low-level steam turbine generator is in the fully-open valve operation mode, the low-level generator load is determined according to the pressure of the high-level steam turbine generator exhaust steam after secondary reheating, and the low-level generator load does not exceed the low-level load threshold.

[0060] In the present embodiment, selecting to enter the valve fully open operation mode means that the operator can choose or not select the valve fully open operation mode. In addition, the entry conditions can be customized according to the actual application. For example, in the present embodiment, the entry conditions can be implemented as the unit load instruction being greater than the rated load of the first preset ratio and the high-level generator load being greater than the high-level minimum load corresponding to the high-level steam turbine generator, wherein the first preset ratio can be customized according to the actual application. For example, in the present embodiment, the first preset ratio can be implemented as 30%.

[0061] In this embodiment, automatically entering the valve full-open operation mode means that the operator can enter the valve full-open operation mode without any selection. In addition, the automatic entry conditions can be customized according to the actual application. For example, in this embodiment, the automatic entry conditions can be implemented as a tripping or load shedding of the high-position steam turbine generator.

[0062] In this embodiment, when the low-level steam turbine generator is in the load control mode, the low-level generator load can be specifically determined according to the function F1(x) of the pressure of the exhaust steam of the high-level steam turbine generator after secondary reheating. For example, according to the starting curve of the low-level steam turbine generator and by superimposing 50MW on the corresponding load, F1(x) can be obtained as follows:

[0063] x-secondary pressure (MPa) 0 0.73 0.95 1.17 1.72 2.29 2.37 2.45 y-Load setting (MW) 0 260 350 425 613 800 830 850

[0064] At the same time, the low generator load does not exceed the low load threshold, that is, the low generator load is limited by the upper low load threshold, wherein the low load threshold can be customized according to actual applications.

[0065] Specifically, for example, the low load threshold corresponding to the entry condition can be determined according to the difference between the unit load instruction and the high minimum load, wherein the high minimum load Pmin corresponding to the high turbine generator is HTThe value can be customized according to the actual application. For example, the value can be 70MW to ensure the minimum load of the high-level steam turbine generator while opening the steam inlet regulating valve of the low-level steam turbine generator as much as possible to reduce throttling losses and improve the economy of the unit.

[0066] For another example, the low load threshold corresponding to the automatic entry condition can be determined as the low maximum load corresponding to the low steam turbine generator, that is, when the high steam turbine generator trips or sheds load, the low load threshold automatically switches to the low maximum load corresponding to the low steam turbine generator, where the low maximum load Pmax LT The value can be customized according to the actual application. For example, the value can be 700MW to maximize the consumption of secondary reheat steam work, reduce the energy loss of working fluid entering the condenser through the bypass, and prevent overload of the low-level steam turbine generator.

[0067] Specifically, when the low-level steam turbine generator meets the second condition, the low-level steam turbine generator automatically enters the pressure control mode. In this embodiment, the second condition can be customized according to the actual application. For example, in this embodiment, the second condition can be implemented as at least one of the following: the low-level steam turbine generator bypass is fully closed, the high-level steam turbine generator is started, and the non-low-level steam turbine generator or non-high-level steam turbine generator trips or sheds load, resulting in auxiliary machine failure and load reduction.

[0068] In this embodiment, step S101 may further include:

[0069] When the low-level steam turbine generator is in pressure control mode, the low-level steam inlet pressure setting is determined according to the low-level generator load and the correction amount, and the upper limit of the low-level steam inlet pressure setting is determined according to the last-stage cylinder steam inlet pressure of the high-level steam turbine generator.

[0070] In this embodiment, when the low-level steam turbine generator is in the pressure control mode, the low-level steam inlet pressure setting can be specifically determined according to the function F2(x) of the low-level generator load. When the unit enters the coordination mode, the correction amount Corr1 is superimposed on F2(x). For example, according to the low-level steam turbine generator startup curve, taking into account the unit regulation quality and the throttling loss of the regulating valve, F2(x) can be obtained as follows:

[0071]

[0072]

[0073] At the same time, there is an upper limit for the low-level steam inlet pressure setting. Specifically, the upper limit for the low-level steam inlet pressure setting can be determined according to the function F3(x) of the steam inlet pressure of the last cylinder of the high-level steam turbine generator to prevent the high-level steam turbine generator pressure ratio protection from being actuated and form the final steam inlet pressure setting. For example, according to the high-level steam turbine generator pressure ratio protection setting, F3(x) can be obtained as follows:

[0074] x-repeated pressure (MPa) 0 2.7 3.6 4.5 6.7 9 9.4 9.6 y-Upper limit of secondary pressure (MPa) 0.83 0.83 1 1.22 1.77 2.29 2.37 2.45

[0075] In this embodiment, the adjustment accuracy and response speed of the coordinated control system and the primary frequency modulation can be improved by correcting the correction amount, and the correction amount can be specifically customized according to the actual application.

[0076] For example, in this embodiment, the correction amount Corr1 can be determined according to the function F4(x) of the weighted sum of the unit variable load overshoot, the primary frequency regulation action amount, and the load pullback amount of the high-level steam turbine generator by the main steam pressure deviation. For example, according to the unit variable load test, F4(x) can be obtained as follows:

[0077] x-Load correction (MW) -10 -5 0 5 10 y-pressure correction (MPa) 0.3 0.17 0 -0.17 -0.3

[0078] Furthermore, F4(x) may also have a correction coefficient, which may be customized according to actual application. For example, in this embodiment, the correction coefficient of F4(x) may be determined according to the function F5(x) of the unit load instruction, that is, the correction amount may be determined according to the weighted sum of the above three and the unit load instruction. For example, according to the unit variable load test, F5(x) may be obtained as follows:

[0079] x-unit load command (MW) 0 405 540 675 1013 1280 1350 1500 y-correction factor 1 0.7 0.8 0.85 1 0.9 0.81 0.7

[0080] For another example, in this embodiment, when the total valve position command of the high-level steam turbine is greater than the second preset ratio and the actual load of the unit is less than the unit load command, the correction amount is determined according to the difference between the actual load of the unit and the unit load command, wherein the second preset ratio can be customized according to the actual application, for example, it can be realized as 90%, and the correction amount can be specifically determined according to the function F6(x) of the deviation between the actual load of the unit and the unit load command. For example, according to the unit variable load test, F6(x) can be obtained as follows:

[0081] x-load deviation (MW) 30 20 10 5 y-pressure correction (MPa) -0.17 -0.09 -0.04 0

[0082] In this embodiment, step S101 may further include:

[0083] The high-level generator load is determined based on the difference between the unit load command and the actual load of the low-level steam turbine generator.

[0084] Specifically, in this embodiment, when the actual load corresponding to the low-level steam turbine generator is determined, the high-level generator load setting corresponding to the high-level steam turbine generator can be expressed by the following formula:

[0085] MWD1=ULD-PEL LT +PSF LT-F7(x)·F8(x)

[0086] Among them, MWD1 represents the high-level generator load corresponding to the high-level steam turbine generator, that is, the load setting of the high-level steam turbine generator (MW), ULD represents the unit load instruction (MW), PEL LT Indicates the actual load of the low-level steam turbine generator (MW), PSF LT represents the primary frequency modulation component of the low-level steam turbine generator (MW), F7(x) represents the function of the correction amount F4(x) (MW), and F8(x) represents the function of the unit load command.

[0087] In this embodiment, if the primary frequency modulation is not superimposed on the turbine control system (TCS) side, the above formula should also add the primary frequency modulation component PSF of the high-level turbine generator: HT .

[0088] In this embodiment, when the low-level steam turbine generator is not in the pressure control mode, or the unit is not in the coordination mode, F7(x)·F8(x) is cut to "0". For example, according to the coupling characteristics of the high-level and low-level steam turbine generator loads, F7(x) can be obtained as follows:

[0089] x-pressure correction (MPa) -0.3 -0.08 0.03 0.3 y-Load correction (MW) -15 0 0 20

[0090] F8(x) can be obtained as follows:

[0091] x-unit load command (MW) 0 540 675 1013 1215 1280 1350 y-correction factor 1 1 1 1 0.9 0.5 0

[0092] In this embodiment, the high and low steam turbine generator loads can be automatically distributed according to the automatic generation control (AGC) or the unit load instructions given by the operator, and the high and low steam turbine inlet pressure settings are generated respectively, so as to achieve the optimal distribution of the load, and at the same time meet the requirements of the coordinated control system regulation quality and primary frequency regulation, and at the same time enable the two steam turbine generators in the high and low dual-axis arrangement to be well accepted by the grid dispatch as a whole power generation unit, which greatly improves the safety and economy of this type of unit, adapts to the innovation of coal-fired power generation technology, and has a strong practical significance.

[0093] Example 2

[0094] This embodiment provides a coordinated control system for a dual-shaft steam turbine generator set. The dual-shaft steam turbine generator set includes a low-position steam turbine generator and a high-position steam turbine generator. For example, Figure 1 The structure of the dual-shaft steam turbine generator set is shown, but it should be understood that the selection of high and low position 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 the present invention.

[0095] This embodiment will be described with reference to the parameters of a million-kilowatt class unit.

[0096] The coordinated control system provided in this embodiment is used to determine the coordinated control parameters according to the unit load instructions, wherein the coordinated control parameters include the low-level generator load corresponding to the low-level steam turbine generator, the high-level generator load corresponding to the high-level steam turbine generator, the low-level steam inlet pressure setting corresponding to the low-level steam turbine generator, and the high-level steam inlet pressure setting corresponding to the high-level steam turbine generator.

[0097] In this embodiment, after the low-level steam turbine generator is connected to the grid, in the unit coordination mode, the operator can manually select the low-level steam turbine generator as load control mode or pressure control mode according to different usage requirements. At the same time, the triggering of specific conditions can also cause the low-level steam turbine generator to automatically enter the load control mode or pressure control mode, thereby realizing automatic conversion between the two modes. Among them, the load control mode can be divided into manual setting mode and valve full-open operation mode.

[0098] Specifically, when the low-level steam turbine generator meets the first condition, the low-level steam turbine generator automatically enters the load control mode. In this embodiment, the first condition can be customized according to the actual application. For example, in this embodiment, the first condition can be implemented as the low-level steam turbine generator bypass is opened, that is, when the low-level steam turbine generator bypass is opened, the low-level steam turbine generator automatically enters the load control mode.

[0099] In this embodiment, the coordinated control system is specifically used for, when the low-level steam turbine generator is in the load control mode and in the manual setting mode, the low-level generator load is determined by manual input.

[0100] Specifically, in this embodiment, when the low-level steam turbine generator is in the manual setting mode, the operator can set the required low-level generator load according to actual application.

[0101] Furthermore, in this embodiment, the coordinated control system is also specifically used for:

[0102] When the low-level steam turbine generator is in load control mode and meets the selection entry conditions, the low-level steam turbine generator selects to enter the valve full-open operation mode;

[0103] When the low-level steam turbine generator is in load control mode and meets the automatic entry conditions, the low-level steam turbine generator automatically enters the valve full-open operation mode;

[0104] When the low-level steam turbine generator is in the fully-open valve operation mode, the low-level generator load is determined according to the pressure of the high-level steam turbine generator exhaust steam after secondary reheating, and the low-level generator load does not exceed the low-level load threshold.

[0105] In the present embodiment, selecting to enter the valve fully open operation mode means that the operator can choose or not select the valve fully open operation mode. In addition, the entry conditions can be customized according to the actual application. For example, in the present embodiment, the entry conditions can be implemented as the unit load instruction being greater than the rated load of the first preset ratio and the high-level generator load being greater than the high-level minimum load corresponding to the high-level steam turbine generator, wherein the first preset ratio can be customized according to the actual application. For example, in the present embodiment, the first preset ratio can be implemented as 30%.

[0106] In this embodiment, automatically entering the valve full-open operation mode means that the operator can enter the valve full-open operation mode without any selection. In addition, the automatic entry conditions can be customized according to the actual application. For example, in this embodiment, the automatic entry conditions can be implemented as a tripping or load shedding of the high-position steam turbine generator.

[0107] In this embodiment, when the low-level steam turbine generator is in the load control mode, the low-level generator load can be specifically determined according to the function F1(x) of the pressure of the exhaust steam of the high-level steam turbine generator after secondary reheating. For example, according to the starting curve of the low-level steam turbine generator and by superimposing 50MW on the corresponding load, F1(x) can be obtained as follows:

[0108] x-secondary pressure (MPa) 0 0.73 0.95 1.17 1.72 2.29 2.37 2.45 y-Load setting (MW) 0 260 350 425 613 800 830 850

[0109] At the same time, the low generator load does not exceed the low load threshold, that is, the low generator load is limited by the upper low load threshold, wherein the low load threshold can be customized according to actual applications.

[0110] Specifically, for example, the low load threshold corresponding to the entry condition can be determined according to the difference between the unit load instruction and the high minimum load, wherein the high minimum load Pmin corresponding to the high turbine generator is HT The value can be customized according to the actual application. For example, the value can be 70MW to ensure the minimum load of the high-level steam turbine generator while opening the steam inlet regulating valve of the low-level steam turbine generator as much as possible to reduce throttling losses and improve the economy of the unit.

[0111] For another example, the low load threshold corresponding to the automatic entry condition can be determined as the low maximum load corresponding to the low steam turbine generator, that is, when the high steam turbine generator trips or sheds load, the low load threshold automatically switches to the low maximum load corresponding to the low steam turbine generator, where the low maximum load Pmax LT The value can be customized according to the actual application. For example, the value can be 700MW to maximize the consumption of secondary reheat steam work, reduce the energy loss of working fluid entering the condenser through the bypass, and prevent overload of the low-level steam turbine generator.

[0112] Specifically, when the low-level steam turbine generator meets the second condition, the low-level steam turbine generator automatically enters the pressure control mode. In this embodiment, the second condition can be customized according to the actual application. For example, in this embodiment, the second condition can be implemented as at least one of the following: the low-level steam turbine generator bypass is fully closed, the high-level steam turbine generator is started, and the non-low-level steam turbine generator or non-high-level steam turbine generator trips or sheds load, resulting in auxiliary machine failure and load reduction.

[0113] In this embodiment, the coordinated control system is specifically used for, when the low-level steam turbine generator is in the pressure control mode, the low-level steam inlet pressure setting is determined according to the low-level generator load and the correction amount, and the upper limit of the low-level steam inlet pressure setting is determined according to the last-stage cylinder steam inlet pressure of the high-level steam turbine generator.

[0114] In this embodiment, when the low-level steam turbine generator is in the pressure control mode, the low-level steam inlet pressure setting can be specifically determined according to the function F2(x) of the low-level generator load. When the unit enters the coordination mode, the correction amount Corr1 is superimposed on F2(x). For example, according to the low-level steam turbine generator startup curve, taking into account the unit regulation quality and the throttling loss of the regulating valve, F2(x) can be obtained as follows:

[0115]

[0116]

[0117] At the same time, there is an upper limit for the low-level steam inlet pressure setting. Specifically, the upper limit for the low-level steam inlet pressure setting can be determined according to the function F3(x) of the steam inlet pressure of the last cylinder of the high-level steam turbine generator to prevent the high-level steam turbine generator pressure ratio protection from being actuated and form the final steam inlet pressure setting. For example, according to the high-level steam turbine generator pressure ratio protection setting, F3(x) can be obtained as follows:

[0118] x-repeated pressure (MPa) 0 2.7 3.6 4.5 6.7 9 9.4 9.6 y-Upper limit of secondary pressure (MPa) 0.83 0.83 1 1.22 1.77 2.29 2.37 2.45

[0119] In this embodiment, the adjustment accuracy and response speed of the coordinated control system and the primary frequency modulation can be improved by correcting the correction amount, and the correction amount can be specifically customized according to the actual application.

[0120] For example, in this embodiment, the correction amount Corr1 can be determined according to the function F4(x) of the weighted sum of the unit variable load overshoot, the primary frequency regulation action amount, and the load pullback amount of the high-level steam turbine generator by the main steam pressure deviation. For example, according to the unit variable load test, F4(x) can be obtained as follows:

[0121] x-Load correction (MW) -10 -5 0 5 10 y-pressure correction (MPa) 0.3 0.17 0 -0.17 -0.3

[0122] Furthermore, F4(x) may also have a correction coefficient, which may be customized according to actual application. For example, in this embodiment, the correction coefficient of F4(x) may be determined according to the function F5(x) of the unit load instruction, that is, the correction amount may be determined according to the weighted sum of the above three and the unit load instruction. For example, according to the unit variable load test, F5(x) may be obtained as follows:

[0123] x-unit load command (MW) 0 405 540 675 1013 1280 1350 1500 y-correction factor 1 0.7 0.8 0.85 1 0.9 0.81 0.7

[0124] For another example, in this embodiment, when the total valve position command of the high-level steam turbine is greater than the second preset ratio and the actual load of the unit is less than the unit load command, the correction amount is determined according to the difference between the actual load of the unit and the unit load command, wherein the second preset ratio can be customized according to the actual application, for example, it can be realized as 90%, and the correction amount can be specifically determined according to the function F6(x) of the deviation between the actual load of the unit and the unit load command. For example, according to the unit variable load test, F6(x) can be obtained as follows:

[0125] x-load deviation (MW) 30 20 10 5 y-pressure correction (MPa) -0.17 -0.09 -0.04 0

[0126] In this embodiment, the coordinated control system is specifically used to determine the high-level generator load according to the difference between the unit load instruction and the actual load of the low-level steam turbine generator.

[0127] Specifically, in this embodiment, when the actual load corresponding to the low-level steam turbine generator is determined, the high-level generator load setting corresponding to the high-level steam turbine generator can be expressed by the following formula:

[0128] MWD1=ULD-PEL LT +PSF LT -F7(x)·F8(x)

[0129] Among them, MWD1 represents the high-level generator load corresponding to the high-level steam turbine generator, that is, the load setting of the high-level steam turbine generator (MW), ULD represents the unit load instruction (MW), PEL LT Indicates the actual load of the low-level steam turbine generator (MW), PSF LT represents the primary frequency modulation component of the low-level steam turbine generator (MW), F7(x) represents the function of the correction amount F4(x) (MW), and F8(x) represents the function of the unit load command.

[0130] In this embodiment, if the primary frequency modulation is not superimposed on the turbine control system (TCS) side, the above formula should also add the primary frequency modulation component PSF of the high-level turbine generator: HT .

[0131] In this embodiment, when the low-level steam turbine generator is not in the pressure control mode, or the unit is not in the coordination mode, F7(x)·F8(x) is cut to "0". For example, according to the coupling characteristics of the high-level and low-level steam turbine generator loads, F7(x) can be obtained as follows:

[0132] x-pressure correction (MPa) -0.3 -0.08 0.03 0.3 y-Load correction (MW) -15 0 0 20

[0133] F8(x) can be obtained as follows:

[0134] x-unit load command (MW) 0 540 675 1013 1215 1280 1350 y-correction factor 1 1 1 1 0.9 0.5 0

[0135] In this embodiment, the high and low steam turbine generator loads can be automatically distributed according to the automatic generation control (AGC) or the unit load instructions given by the operator, and the high and low steam turbine inlet pressure settings are generated respectively, so as to achieve the optimal distribution of the load, and at the same time meet the requirements of the coordinated control system regulation quality and primary frequency regulation, and at the same time enable the two steam turbine generators in the high and low dual-axis arrangement to be well accepted by the grid dispatch as a whole power generation unit, which greatly improves the safety and economy of this type of unit, adapts to the innovation of coal-fired power generation technology, and has a strong practical significance.

[0136] Example 3

[0137] This embodiment provides an electronic device, which can be expressed in the form of a computing device (for example, a server device), 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, the coordinated control method of the dual-axis steam turbine generator set provided in Embodiment 1 can be implemented.

[0138] Figure 4 FIG. 4 shows a schematic diagram of the hardware structure of this embodiment. Figure 4 As shown, the electronic device 9 specifically includes:

[0139] At least one processor 91, at least one memory 92, and a bus 93 for connecting different system components (including the processor 91 and the memory 92), wherein:

[0140] The bus 93 includes a data bus, an address bus, and a control bus.

[0141] The memory 92 includes a volatile memory, such as a random access memory (RAM) 921 and / or a cache memory 922 , and may further include a read-only memory (ROM) 923 .

[0142] Memory 92 also includes a program / utility 925 having a set (at least one) of program modules 924, such program modules 924 including but not limited to: an operating system, one or more application programs, other program modules and program data, each of which or some combination may include an implementation of a network environment.

[0143] The processor 91 executes various functional applications and data processing by running the computer program stored in the memory 92, such as the coordinated control method of the dual-shaft steam turbine generator set provided in Example 1 of the present invention.

[0144] The electronic device 9 can further communicate with one or more external devices 94 (e.g., keyboards, pointing devices, etc.). Such communication can be performed through an input / output (I / O) interface 95. In addition, the electronic device 9 can also communicate with one or more networks (e.g., local area networks (LANs), wide area networks (WANs), and / or public networks, such as the Internet) through a network adapter 96. The network adapter 96 communicates with other modules of the electronic device 9 through a bus 93. It should be understood that, although not shown in the figure, other hardware and / or software modules can be used in conjunction with the 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.

[0145] It should be noted that although several units / modules or sub-units / modules of the electronic device are mentioned in the above detailed description, this division is merely exemplary and not mandatory. In fact, according to the embodiments of the present 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 into multiple units / modules to be embodied.

[0146] Example 4

[0147] This embodiment provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the steps of the coordinated control method of the dual-axis steam turbine generator set provided in Embodiment 1 are implemented.

[0148] The readable storage medium may include but is not limited to: a portable disk, a hard disk, a random access memory, a read-only memory, an erasable programmable read-only memory, an optical storage device, a magnetic storage device or any suitable combination of the above.

[0149] In a possible implementation, the present invention can also be implemented in the form of a program product, which includes a program code. When the program product is run on a terminal device, the program code is used to enable the terminal device to execute the steps of the coordinated control method of the dual-axis steam turbine generator set described in Example 1.

[0150] The program code for executing the present invention may be written in any combination of one or more programming languages, and may be executed entirely on a user device, partially on a user device, as an independent software package, partially on a user device and partially on a remote device, or entirely on a remote device.

[0151] Although the specific embodiments of the present invention are described above, it should be understood by those skilled in the art that this is only for illustration and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A coordinated control method for a dual-shaft steam turbine generator set, characterized in that: The dual-shaft steam turbine generator set includes a low-position steam turbine generator and a high-position steam turbine generator, and the coordinated control method includes: Determine the coordinated control parameters according to the unit load instruction, the coordinated control parameters including the low-level generator load corresponding to the low-level steam turbine generator, the high-level generator load corresponding to the high-level steam turbine generator, the low-level steam inlet pressure setting corresponding to the low-level steam turbine generator, and the high-level steam inlet pressure setting corresponding to the high-level steam turbine generator; Determining the coordinated control parameters according to the unit load instruction includes: When the low-level steam turbine generator is in the load control mode and meets the selection entry conditions, the low-level steam turbine generator selects to enter the valve full-open operation mode; When the low-position steam turbine generator is in the load control mode and meets the automatic entry conditions, the low-position steam turbine generator automatically enters the valve full-open operation mode; When the low-level steam turbine generator is in a fully-open valve operation mode, the low-level generator load is determined according to the pressure of the exhaust steam of the high-level steam turbine generator after secondary reheating, and the low-level generator load does not exceed the low-level load threshold.

2. The coordinated control method of a dual-shaft steam turbine generator set according to claim 1, characterized in that: The selection entry condition includes: the unit load command is greater than the rated load of the first preset ratio and the high-level generator load is greater than the high-level minimum load corresponding to the high-level steam turbine generator, and the low-level load threshold corresponding to the selection entry condition is determined according to the difference between the unit load command and the high-level minimum load; and / or, The automatic entry condition includes tripping or load shedding of the high-level steam turbine generator, and the low-level load threshold corresponding to the automatic entry condition is the low-level maximum load corresponding to the low-level steam turbine generator.

3. The coordinated control method of a dual-shaft steam turbine generator set according to claim 1, characterized in that: The step of determining the coordinated control parameters according to the unit load instruction further includes: When the low-level steam turbine generator bypass is opened, the low-level steam turbine generator automatically enters a load control mode; and / or, The coordinated control method further comprises: When the low-level steam turbine generator is in load control mode and in manual setting mode, the low-level generator load is determined by manual input; and / or, The step of determining the coordinated control parameters according to the unit load instruction further includes: The high-level generator load is determined according to the difference between the unit load instruction and the actual load of the low-level steam turbine generator.

4. The coordinated control method of a dual-shaft steam turbine generator set according to claim 1, characterized in that: Determining the coordinated control parameters according to the unit load instruction includes: When the low-level steam turbine generator is in pressure control mode, the low-level steam inlet pressure setting is determined according to the low-level generator load and the correction amount, and the upper limit of the low-level steam inlet pressure setting is determined according to the last-stage cylinder steam inlet pressure of the high-level steam turbine generator.

5. The coordinated control method of a dual-shaft steam turbine generator set according to claim 4, characterized in that: The correction amount is determined according to the weighted sum of the load overshoot of the unit, the primary frequency regulation action amount, the main steam pressure deviation and the load pullback amount of the high-level steam turbine generator and the unit load instruction; and / or, When the total valve position instruction of the high-level steam turbine generator is greater than the second preset ratio and the actual load of the unit is less than the unit load instruction, the correction amount is determined according to the difference between the actual load of the unit and the unit load instruction.

6. The coordinated control method of a dual-shaft steam turbine generator set according to claim 4, characterized in that: The coordinated control method further comprises: When the bypass of the low-level steam turbine generator is fully closed, the low-level steam turbine generator automatically enters the pressure control mode; and / or, When the high-position steam turbine generator is started, the low-position steam turbine generator automatically enters a pressure control mode; and / or, When a trip or load shedding occurs to a non-low-position steam turbine generator or a non-high-position steam turbine generator, resulting in a load reduction due to an auxiliary machine failure, the low-position steam turbine generator automatically enters a pressure control mode.

7. A coordinated control system for a dual-shaft steam turbine generator set, characterized in that: The dual-shaft steam turbine generator set comprises a low-position steam turbine generator and a high-position steam turbine generator; The coordinated control system is used to determine coordinated control parameters according to the unit load command, and the coordinated control parameters include the low-level generator load corresponding to the low-level steam turbine generator, the high-level generator load corresponding to the high-level steam turbine generator, the low-level steam inlet pressure setting corresponding to the low-level steam turbine generator, and the high-level steam inlet pressure setting corresponding to the high-level steam turbine generator; The coordinated control system is also used specifically for: When the low-level steam turbine generator is in load control mode and meets the selection entry conditions, the low-level steam turbine generator selects to enter the valve full-open operation mode; When the low-level steam turbine generator is in load control mode and meets the automatic entry conditions, the low-level steam turbine generator automatically enters the valve full-open operation mode; When the low-level steam turbine generator is in the fully-open valve operation mode, the low-level generator load is determined according to the pressure of the high-level steam turbine generator exhaust steam after secondary reheating, and the low-level generator load does not exceed the low-level load threshold.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the coordinated control method of the dual-shaft steam turbine generator set according to any one of claims 1 to 6 is implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the coordinated control method of a dual-shaft steam turbine generator set according to any one of claims 1 to 6 are implemented.

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