Control method and system for correcting main steam pressure through gas turbine valve opening degree of gas turbine

Abstract

The invention discloses a control method and system for correcting main steam pressure through gas turbine valve opening of a gas turbine. The system comprises a first function x module, a first function t module, a second function t module and a first small selection module. The steam flow is connected with a first function x module, and the first function x module is connected to the first function t module and the second function t module respectively and then connected to the first small selection module and the basic main steam pressure. The method comprises the steps that steam flow is converted through a first function x module, a first function t module, a second function t module and a first small selection module, and then basic main steam pressure is obtained; when the temperature state is 1, the first switching module outputs the temperature state impulse pressure, and when the temperature state is 0, the first switching module outputs the cold state impulse pressure; when the thermal state is 1, the second switching module outputs thermal state impulse pressure, and when the thermal state is 0, the second switching module outputs the output of the first switching module; and finally, the output end of the second switching module obtains the impulse pressure of the steam turbine.

Description

Technical Field

[0001] The invention belongs to the field of intelligent control of thermal power plants, and in particular relates to a control method and system for correcting main steam pressure by valve opening of a steam turbine of a gas unit. Background Art

[0002] The main steam pressure of the gas-steam combined cycle unit is generally calculated based on the evaporation volume of the waste heat boiler. After the turbine is started up and meshed (or connected to the grid), the main steam pressure of the combined cycle unit is maintained at the designed main steam pressure by the turbine and the bypass system. After the unit load changes or the steam system (external steam supply) changes, the original designed main steam pressure setting will deviate from the actual operating demand value. For example, if the set main steam pressure is greater than the current actual pressure value, the turbine will close the valve to maintain a higher main steam pressure; if the set main steam pressure is less than the current actual pressure value, the turbine will open the valve to maintain a lower main steam pressure. When the valve is fully opened and the lower set pressure cannot be met, the bypass system will intervene to assist in reducing the main steam pressure; during the rapid load change of the unit, the gas turbine has a smaller thermal inertia than the waste heat boiler, and the deviation between the main steam pressure setting and the current actual main steam pressure will frequently increase, resulting in frequent opening or closing of the turbine valve, and even bypass opening to assist in pressure relief. Summary of the invention

[0003] The purpose of the present invention is to provide a control method and system for correcting the main steam pressure of a gas turbine valve opening, which can automatically adjust the main steam pressure set value according to the change of the turbine valve opening, thereby stabilizing the turbine valve opening and avoiding accidental opening of the bypass, realizing energy-saving and efficient operation of the gas-steam combined cycle, and eliminating the risk of fluctuations in the fire-resistant fuel system caused by valve fluctuations.

[0004] In order to achieve the above object, the present invention adopts the following technical solution: A control system for correcting main steam pressure of a gas turbine valve opening, comprising a first function x module, a first function t module, a second function t module and a first small selection module; The steam flow is connected to the first function x module, the first function x module is connected to the first function t module and the second function t module respectively, and then connected to the first small selection module and the basic main steam pressure.

[0005] A further improvement of the present invention is that it further comprises a first switching module and a second switching module; The cold-state impulse pressure is connected to the N-end of the first switching module, the warm-state impulse pressure is connected to the Y-end of the first switching module, the warm state is connected to the trigger end of the first switching module, the output end of the first switching module is connected to the N-end of the second switching module, the hot-state impulse pressure is connected to the Y-end of the second switching module, the hot state is connected to the trigger end of the second switching module, and the output end of the second switching module is connected to the turbine impulse pressure.

[0006] A further improvement of the present invention is that it also includes a first or module and a first and module; Both the single-shaft-turbine not engaged and the split-shaft-turbine not connected to the grid are connected to the first OR module, and the output end of the first OR module is connected to the first AND module during the unit startup process, and the output end of the first AND module is connected to the turbine not output.

[0007] A further improvement of the present invention is that it further comprises a first-order inertia module, a first subtraction module, a first less than module, a first greater than module and a first SR module; The turbine flow command is connected to the first-order inertia module, the output end of the turbine flow command and the output end of the first-order inertia module are both connected to the first subtraction module, the output end of the first subtraction module is respectively connected to the first less than module and the first greater than module, the output end of the first less than module is connected to the S end of the first SR module, the output end of the first greater than module is connected to the R end of the first SR module, and the output end of the first SR module is connected to the turbine flow command reduction.

[0008] A further improvement of the present invention is that it also includes a second subtraction module, a delay disconnection module, a first addition module, a third switching module, a first negation module, a fourth switching module and a rate module; The turbine rush pressure and the basic main steam pressure are both connected to the second subtraction module, the output end of the second subtraction module is connected to the Y end of the third switching module, the first constant zero is connected to the N end of the third switching module, the turbine under-output is connected to the delayed disconnection module and the trigger end of the third switching module in sequence, the turbine under-output is connected to the first non-module, the pressure switching rate is connected to the N end of the fourth switching module, the second constant zero is connected to the Y end of the fourth switching module, the turbine flow command reduction is connected to the trigger end of the fourth switching module, the third switching module, the first non-module, and the fourth switching module are all connected to the rate module, the rate module and the basic main steam pressure are all connected to the first addition module, and the output end of the first addition module is connected to the pressure setting after the rush pressure correction.

[0009] A further improvement of the present invention is that it further comprises a third subtraction module, a fourth subtraction module, a pure integration module and a second addition module; The pressure before the main steam valve of the turbine and the pressure bias are both connected to the second subtraction, the pressure setting after the start-up pressure correction and the second subtraction are both connected to the third subtraction, the output end of the third subtraction, the third constant zero, and the combined cycle of the unit are all connected to the pure integration module, the pressure setting after the start-up pressure correction and the pure integration module are both connected to the second addition module, and the output end of the second addition module is connected to the effective pressure setting.

[0010] A control method for correcting the main steam pressure by the valve opening of a gas turbine unit, the method is based on the control system for correcting the main steam pressure by the valve opening of a gas turbine unit, comprising: The steam flow is converted through the first function x module, the first function t module, the second function t module and the first small selection module to obtain the basic main steam pressure; When the warm state is 1, the first switching module outputs the warm-state starting pressure, and when the warm state is 0, the first switching module outputs the cold-state starting pressure; when the hot state is 1, the second switching module outputs the hot-state starting pressure, and when the hot state is 0, the second switching module outputs the output of the first switching module; finally, the output end of the second switching module obtains the turbine starting pressure.

[0011] A further improvement of the present invention is that it also includes: Single-shaft-turbine is not meshed or split-shaft-turbine is not connected to the grid. When any module is 1 and the unit is in the startup process, the turbine is not outputting. The control mode of the steam turbine flow command reduction module includes: the steam turbine flow command is reduced after being judged by the first-order inertia module, the first subtraction module, the first less than module, the first greater than module and the first SR module.

[0012] A further improvement of the present invention is that it also includes: When the turbine flow command is reduced to 1, the output of the fourth switching module is the second constant zero; when the turbine flow command is reduced to 0, the output of the fourth switching module is the pressure switching rate; the turbine start-up pressure is subtracted from the basic main steam pressure; when the delayed disconnection module is 1, the output is the output of the second subtraction module; when the delayed disconnection module is 0, the first constant zero is output; according to the state of the first non-module, the output end of the rate module is added to the basic main steam pressure, and the output end of the first addition module is the pressure setting after the start-up pressure correction.

[0013] A further improvement of the present invention is that it also includes: The pressure before the main steam valve of the steam turbine and the pressure offset are calculated using the third subtraction module, and the pressure setting after the start-up pressure correction is subtracted from the output of the third subtraction module. When the combined cycle of the unit is 1, the output of the pure integration module is the output of the fourth subtraction module, and the pressure setting after the start-up pressure correction and the pure integration module are input to the second addition module, and the output of the second addition module is the effective pressure setting.

[0014] Compared with the prior art, the present invention has at least the following beneficial technical effects: The control method and system for correcting the main steam pressure of the gas turbine valve opening provided by the present invention solve the following two problems: 1) When the deviation between the turbine start-up pressure and the main steam pressure setting is large during the cold or warm start-up process, there is a risk that the turbine valve will be closed to maintain a higher main steam pressure setting after the turbine is engaged (or connected to the grid); 2) The main steam pressure setting is adaptive throughout the unit's load change process to achieve a stable turbine valve opening and keep the bypass fully closed, reducing the risk of turbine throttling losses and oil pressure fluctuations in the fire-resistant fuel system.

[0015] In summary, the control method and system for correcting the main steam pressure of the gas turbine valve opening of the present invention finally realizes that the main steam pressure transmitted to the turbine in the control system is set to be less than the current actual pressure, and the bypass setting pressure is greater than the current actual pressure. The stable turbine valve is fully open and the bypass is kept fully closed. When the current actual pressure suddenly increases due to turbine failure or other reasons, the bypass can quickly intervene and maintain the main steam pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figures 1 to 6 The schematic diagram of the control system used to correct the main steam pressure of the gas turbine valve opening Figure 7 This is a rendering of the third embodiment of the present invention.

[0017] Figure 8 This is a rendering of the fourth embodiment of the present invention. DETAILED DESCRIPTION

[0018] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0019] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0020] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0021] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0023] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0024] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0025] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0026] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0027] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0028] Example 1 1) Design a control method and system for correcting the main steam pressure of the gas turbine valve opening. According to the change of the turbine valve opening, the main steam pressure set value is automatically adjusted to stabilize the turbine valve opening and avoid accidental opening of the bypass, so as to achieve energy-saving and efficient operation of the gas-steam combined cycle and eliminate the risk of fluctuations in the fire-resistant fuel system caused by valve fluctuations.

[0029] 2) The control system principle for correcting the main steam pressure of the gas turbine valve opening Figures 1 to 6 .

[0030] Figure 1 and Figure 2 Specifically including: steam flow 001, first function x module 002, first function t module 003, second function t module 004, first small selection module 005, basic main steam pressure 006, cold start pressure 007, warm start pressure 008, warm state 009, hot start pressure 010, hot state 011, first switching module 012, second switching module 013, turbine start pressure 014.

[0031] Figure 1 and Figure 2 The control strategy logic diagram contains: The steam flow 001 is connected to the first function x module 002 , the first function x module 002 is respectively connected to the first function t module 003 and the second function t module 004 , and then connected to the first small selection module 005 and the basic main steam pressure 006 .

[0032] The cold state impulse pressure 007 is connected to the N end of the first switching module 012, the warm state impulse pressure 008 is connected to the Y end of the first switching module 012, the warm state 009 is connected to the trigger end of the first switching module 012, the output end of the first switching module 012 is connected to the N end of the second switching module 013, the hot state impulse pressure 010 is connected to the Y end of the second switching module 013, the hot state 011 is connected to the trigger end of the second switching module 013, and the output end of the second switching module 013 is connected to the turbine impulse pressure 014.

[0033] Figure 3 and Figure 4 Specifically including: during unit startup 015, single-shaft-steam turbine not engaged 016, split-shaft-steam turbine not connected to the grid 017, first or module 018, first and module 019, turbine not output 020, turbine flow instruction 021, first-order inertia module 022, first subtraction module 023, first less than module 024, first greater than module 025, first SR module 026, turbine flow instruction reduction 027.

[0034] Figure 3 and Figure 4 The control strategy logic diagram contains: Single-shaft - turbine not engaged 016 and split-shaft - turbine not connected to the grid 017 are both connected to the first or module 018, the output end of the first or module 018 and the unit startup process 015 are both connected to the first and module 019, and the output end of the first and module 019 is connected to the turbine not output 020.

[0035] The turbine flow command 021 is connected to the first-order inertia module 022, and the output end of the turbine flow command 021 and the output end of the first-order inertia module 022 are both connected to the first subtraction module 023, the output end of the first subtraction module 023 is respectively connected to the first less than module 024 and the first greater than module 025, the output end of the first less than module 024 is connected to the S end of the first SR module 026, the output end of the first greater than module 025 is connected to the R end of the first SR module 026, and the output end of the first SR module 026 is connected to the turbine flow command reduction 027.

[0036] Figure 5 Specifically including: basic main steam pressure 006, turbine run-up pressure 014, turbine under-output 020, pressure switching rate 032, turbine flow command reduction 027, first constant zero 034, second subtraction module 035, delayed disconnection module 036, second constant zero 037, first addition module 038, third switching module 039, first non-module 040, fourth switching module 041, rate module 042, and run-up pressure correction pressure setting 043.

[0037] Figure 5 The control strategy logic diagram contains: The turbine impulse pressure 014 and the basic main steam pressure 006 are both connected to the second subtraction module 035, the output end of the second subtraction module 035 is connected to the Y end of the third switching module 039, the first constant zero 034 is connected to the N end of the third switching module 039, the turbine under-output 020 is connected to the delayed disconnection module 036 and the trigger end of the third switching module 039 in sequence, the turbine under-output 020 is connected to the first non-module 040, the pressure switching rate 032 is connected to the N end of the fourth switching module 041, the second constant zero 037 is connected to the Y end of the fourth switching module 041, the turbine flow command reduction 027 is connected to the trigger end of the fourth switching module 041, the third switching module 039, the first non-module 040, and the fourth switching module 041 are all connected to the rate module 042, the rate module 042 and the basic main steam pressure 006 are all connected to the first addition module 038, and the output end of the first addition module 038 is connected to the pressure setting 043 after the impulse pressure correction.

[0038] Figure 6 Specifically include: pressure setting after start-up pressure correction 043, pressure before turbine main steam valve 045, pressure offset 046, unit combined cycle 047, third subtraction module 048, fourth subtraction module 049, third constant zero 050, pure integration module 051, second addition module 052 and effective pressure setting 053.

[0039] Figure 6 The control strategy logic diagram contains: The pressure before the turbine main steam valve 045 and the pressure offset 046 are both connected to the second subtraction 048, the pressure setting 043 after the start-up pressure correction and the second subtraction 048 are both connected to the third subtraction 049, the output end of the third subtraction 049, the third constant zero 050, and the unit combined cycle 047 are all connected to the pure integration module 051, the pressure setting 043 after the start-up pressure correction and the pure integration module 051 are both connected to the second addition module 052, and the output end of the second addition module 052 is connected to the effective pressure setting 053.

[0040] Example 2 The present invention provides a control method for correcting the main steam pressure of a gas turbine valve opening, comprising: Figure 1 and Figure 2 The control modes are: The control mode of the basic main steam pressure 006 module includes: the steam flow 001 is converted through the first function x module 002, the first function t module 003, the second function t module 004 and the first small selection module 005 to obtain the basic main steam pressure 006.

[0041] The control mode of the turbine impulse pressure 014 module includes: when the warm state 009 is 1, the first switching module 012 outputs the warm impulse pressure 008, and when the warm state 009 is 0, the first switching module 012 outputs the cold impulse pressure 007; when the hot state 011 is 1, the second switching module 013 outputs the hot impulse pressure 010, and when the hot state 011 is 0, the second switching module 013 outputs the output of the first switching module 012; finally, the output end of the second switching module 013 obtains the turbine impulse pressure 014.

[0042] Figure 3 and Figure 4 The control modes are: The control modes of the steam turbine no output 020 module include: single shaft - steam turbine not engaged 016 or split shaft - steam turbine not connected to the grid 017. When any one of the modules is 1 and 015 is during the unit startup process, the steam turbine no output 020 is satisfied.

[0043] The control mode of the steam turbine flow command reduction 027 module includes: the steam turbine flow command 021 is judged by the first-order inertia module 022, the first subtraction module 023, the first less than module 024, the first greater than module 025 and the first SR module 026 to obtain the steam turbine flow command reduction 027.

[0044] Figure 5 The control modes are: The control mode of the pressure setting module 043 after the start-up pressure correction includes: when the turbine flow command reduction 027 is 1, the output of the fourth switching module 041 is the second constant zero 037; when the turbine flow command reduction 027 is 0, the output of the fourth switching module 041 is the pressure switching rate 032; the turbine start-up pressure 014 is subtracted from the basic main steam pressure 006; when the delayed disconnection module 036 is 1, the output is the output of the second subtraction module 035; when the delayed disconnection module 036 is 0, the first constant zero 034 is output; according to the state of the first non-module 040, the output end of the rate module 042 is added to the basic main steam pressure 006, and the output end of the first addition module 038 is the pressure setting 043 after the start-up pressure correction.

[0045] Figure 6 The control modes are: The control mode of the effective pressure setting 053 module includes: the pressure before the main steam valve of the turbine 045 and the pressure offset 046 are calculated by the third subtraction module 048, and the pressure setting 043 after the start-up pressure correction is subtracted from the output end of the third subtraction module 048. When the unit has a combined cycle 047 of 1, the output end of the pure integration module 051 is the output of the fourth subtraction module 049, and the pressure setting 043 after the start-up pressure correction and the pure integration module 051 are input to the second addition module 052, and the output end of the second addition module 052 is the effective pressure setting 053.

[0046] Example 3 After the implementation and application of the technology of the present invention, the sliding pressure curve of the gas turbine is as follows: Figure 7 As shown, 1 is the coordination to the high-pressure pressure set value; 2 is the high-pressure main steam pressure (DEH side); 3 is HP CTRL-V1 POSN MEAS; 4 is the high-pressure bypass steam control valve position feedback, which automatically adjusts the main steam pressure set value according to the change of the turbine valve opening, and the high-pressure main steam pressure is always consistent with the set value.

[0047] Example 4 After the implementation and application of the technology of the present invention, the sliding pressure curve of the gas turbine is as follows: Figure 8 As shown, 1 is the coordination to the high-pressure pressure set value; 2 is the high-pressure main steam pressure (DEH side); 3 is HP CTRL-V1 POSN MEAS; 4 is the high-pressure bypass steam control valve position feedback, which automatically adjusts the main steam pressure set value according to the change of the turbine valve opening, and the high-pressure main steam pressure is always consistent with the set value.

[0048] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0049] In addition, it should be understood that although this specification is described in accordance with the implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art. The above content is only to illustrate the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A control system for correcting the main steam pressure of a gas turbine valve opening, characterized in that: It includes a first function x module (002), a first function t module (003), a second function t module (004) and a first small selection module (005); The steam flow (001) is connected to the first function x module (002), the first function x module (002) is respectively connected to the first function t module (003) and the second function t module (004), and then connected to the first small selection module (005) and the basic main steam pressure (006).

2. The control system for correcting main steam pressure by valve opening of gas turbine according to claim 1, characterized in that: It also includes a first switching module (012) and a second switching module (013); The cold-state impulse pressure (007) is connected to the N-end of the first switching module (012), the warm-state impulse pressure (008) is connected to the Y-end of the first switching module (012), the warm state (009) is connected to the trigger end of the first switching module (012), the output end of the first switching module (012) is connected to the N-end of the second switching module (013), the hot-state impulse pressure (010) is connected to the Y-end of the second switching module (013), the hot state (011) is connected to the trigger end of the second switching module (013), and the output end of the second switching module (013) is connected to the turbine impulse pressure (014).

3. The control system for correcting main steam pressure by valve opening of gas turbine according to claim 2, characterized in that: Also included is a first or module (018) and a first and module (019); The single-shaft-turbine not engaged (016) and the split-shaft-turbine not connected to the grid (017) are both connected to the first or module (018), the output end of the first or module (018) and the unit startup process (015) are both connected to the first and module (019), and the output end of the first and module (019) is connected to the turbine not output (020).

4. The control system for correcting main steam pressure by valve opening of gas turbine according to claim 3, characterized in that: It also includes a first-order inertia module (022), a first subtraction module (023), a first less than module (024), a first greater than module (025) and a first SR module (026); The turbine flow command (021) is connected to the first-order inertia module (022), the output end of the turbine flow command (021) and the output end of the first-order inertia module (022) are both connected to the first subtraction module (023), the output end of the first subtraction module (023) is respectively connected to the first less than module (024) and the first greater than module (025), the output end of the first less than module (024) is connected to the S end of the first SR module (026), the output end of the first greater than module (025) is connected to the R end of the first SR module (026), and the output end of the first SR module (026) is connected to the turbine flow command reduction (027).

5. The control system for correcting main steam pressure by valve opening of gas turbine according to claim 4, characterized in that: It also includes a second subtraction module (035), a delayed disconnection module (036), a first addition module (038), a third switching module (039), a first non-module (040), a fourth switching module (041) and a rate module (042); The turbine run-up pressure (014) and the basic main steam pressure (006) are both connected to the second subtraction module (035), the output end of the second subtraction module (035) is connected to the Y end of the third switching module (039), the first constant zero (034) is connected to the N end of the third switching module (039), the turbine no output (020) is connected to the delay disconnection module (036) and the trigger end of the third switching module (039) in sequence, the turbine no output (020) is connected to the first non-module (040), and the pressure switching rate (032) is connected to the fourth switching module The N end of the fourth switching module (041), the second constant zero (037) is connected to the Y end of the fourth switching module (041), the turbine flow command reduction (027) is connected to the trigger end of the fourth switching module (041), the third switching module (039), the first non-module (040), and the fourth switching module (041) are all connected to the rate module (042), the rate module (042) and the basic main steam pressure (006) are all connected to the first adding module (038), and the output end of the first adding module (038) is connected to the pressure setting (043) after the start pressure correction.

6. The control system for correcting main steam pressure by valve opening of gas turbine according to claim 5, characterized in that: It also includes a third subtraction module (048), a fourth subtraction module (049), a pure integration module (051) and a second addition module (052); The pressure before the main steam valve of the turbine (045) and the pressure offset (046) are both connected to the second subtraction (048), the pressure setting after the start-up pressure correction (043) and the second subtraction (048) are both connected to the third subtraction (049), the output end of the third subtraction (049), the third constant zero (050), and the combined cycle of the unit (047) are all connected to the pure integration module (051), the pressure setting after the start-up pressure correction (043) and the pure integration module (051) are both connected to the second addition module (052), and the output end of the second addition module (052) is connected to the effective pressure setting (053).

7. A control method for correcting the main steam pressure of a gas turbine valve opening, characterized in that: The method is based on the control system for correcting the main steam pressure of the gas turbine valve opening of claim 6, comprising: The steam flow rate (001) is converted through the first function x module (002), the first function t module (003), the second function t module (004) and the first small selection module (005) to obtain the basic main steam pressure (006); When the warm state (009) is 1, the first switching module (012) outputs the warm start-up pressure (008); when the warm state (009) is 0, the first switching module (012) outputs the cold start-up pressure (007); when the hot state (011) is 1, the second switching module (013) outputs the hot start-up pressure (010); when the hot state (011) is 0, the second switching module (013) outputs the output of the first switching module (012); finally, the output end of the second switching module (013) obtains the turbine start-up pressure (014).

8. The control method for correcting main steam pressure by valve opening of a gas turbine according to claim 7, characterized in that: Also includes: Single shaft - turbine not engaged (016) or split shaft - turbine not connected to the grid (017), when any module is 1 and during the unit startup process (015), the turbine is not outputting (020); The control mode of the steam turbine flow command reduction (027) module includes: the steam turbine flow command (021) is judged by the first-order inertia module (022), the first subtraction module (023), the first less than module (024), the first greater than module (025) and the first SR module (026) to obtain the steam turbine flow command reduction (027).

9. The control method for correcting main steam pressure by valve opening of a gas turbine according to claim 8, characterized in that: Also includes: When the turbine flow rate reduction instruction (027) is 1, the output of the fourth switching module (041) is the second constant zero (037); when the turbine flow rate reduction instruction (027) is 0, the output of the fourth switching module (041) is the pressure switching rate (032); the turbine start-up pressure (014) is subtracted from the basic main steam pressure (006); when the delay disconnection module (036) is 1, the output is the output of the second subtraction module (035); when the delay disconnection module (036) is 0, the first constant zero (034) is output; according to the state of the first non-module (040), the output end of the rate module (042) is added to the basic main steam pressure (006), and the output end of the first addition module (038) is the pressure setting (043) after the start-up pressure correction.

10. The control method for correcting main steam pressure by valve opening of a gas turbine according to claim 9, characterized in that: Also includes: The pressure before the main steam valve of the steam turbine (045) and the pressure offset (046) are calculated by the third subtraction module (048), and the pressure setting (043) after the start-up pressure correction is subtracted from the output end of the third subtraction module (048). When the unit has a combined cycle (047) and is 1, the output end of the pure integration module (051) is the output of the fourth subtraction module (049), and the pressure setting (043) after the start-up pressure correction and the pure integration module (051) are input to the second addition module (052), and the output end of the second addition module (052) is the effective pressure setting (053).

Images