A high-pressure bypass control system and method for gas turbine start-up process

Abstract

This invention discloses a high-pressure bypass control system and method for gas turbine startup. The system includes an AND module, a switching module, a rate limiting module, a small selection module, a PID module, and a large selection module. The output of the AND module is connected to the input of the switching module, the output of the rate limiting module is connected to the input of the small selection module, the output of the small selection module is connected to the input of the PID module, and the outputs of the switching module and the PID module are both connected to the input of the large selection module. The method includes: when both the high-pressure or medium-pressure pressure control switch signal and the gas turbine startup switch signal are "1", the output of the switching module is set to 10%. This is then compared with the values ​​calculated by the PID module for the high-pressure steam valve inlet pressure and the start-up pressure setpoints to obtain a high-pressure bypass valve opening control command. This invention solves the problem of poor high-pressure bypass valve adjustment during gas turbine startup and steam connection.

Description

Technical Field

[0001] This invention belongs to the field of intelligent control of thermal power plants, specifically relating to a high-voltage bypass control system and method for the gas turbine start-up process. Background Technology

[0002] In multi-shaft gas-steam combined cycle units with two shafts supporting one turbine, the control of the high-pressure bypass is particularly crucial, especially during the start-up, operation, and shutdown phases. During gas turbine start-up, high-pressure bypass control not only affects the smoothness and reliability of the start-up process but also directly impacts the overall efficiency and safety of the unit. Currently, the bypass control strategies and methods for gas-steam combined cycle units are limited and conventional, making them unsuitable for the different operating conditions during start-up, operation, and shutdown. This leads to frequent malfunctions in the bypass system and instability in the regulating valves. Therefore, optimizing and precisely implementing control strategies is key to ensuring the economical and efficient operation of gas-steam combined cycle units. Summary of the Invention

[0003] The purpose of this invention is to provide a high-pressure bypass control system and method for the gas turbine startup process, so as to solve the problem of poor adjustment effect of high-pressure bypass valve during gas turbine startup and steam connection, significantly improve the startup efficiency and operational stability of the unit, and meet the full-process automated control of high-pressure bypass.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] This invention provides a high-pressure bypass control system for the gas turbine startup process, including an AND module, a switching module, a rate limiting module, a small selection module, a PID module, and a large selection module;

[0006] The output of the switching module is connected to the input of the rate limiting module, the output of the rate limiting module is connected to the input of the small selection module, the output of the small selection module is connected to the input of the PID module, and the outputs of the switching module and the PID module are both connected to the input of the large selection module.

[0007] A further improvement of the present invention is that the input terminal of the module is connected to a switch input signal indicating that the high-pressure or medium-pressure control is not engaged and a switch input signal indicating that the gas turbine has started.

[0008] A further improvement of the present invention is that the input terminal of the switching module is also connected to an analog input signal with a set value of 10%.

[0009] A further improvement of the present invention is that the input terminal of the switching module is also connected to an analog input signal with a set value of 0%.

[0010] A further improvement of the present invention is that the input terminal of the rate limiting module is connected to an analog input signal of the pressure before the high-pressure steam valve.

[0011] A further improvement of the present invention is that the input terminal of the small selection module is also connected to an analog input signal of the stroke pressure setting value.

[0012] A further improvement of the present invention is that the input terminal of the PID module is also connected to an analog input signal of the pressure before the high-pressure steam valve.

[0013] A further improvement of the present invention is that the output of the election module is connected to the opening control command of the high-pressure bypass valve.

[0014] This invention also provides a high-pressure bypass control method for gas turbine startup, which is based on the aforementioned high-pressure bypass control system for gas turbine startup, comprising:

[0015] When both the pressure control switch signal for high pressure or medium pressure and the switch signal for gas turbine start-up are "1", the output of the switching module is 10% of the set value. This value is then compared with the values ​​calculated by the PID module for the pressure before the high pressure steam valve and the start-up pressure, to obtain the high pressure bypass valve opening control command.

[0016] A further improvement of this invention is that when both the pressure control switch signal for high pressure or medium pressure and the start-up switch signal for gas turbine are "0", or when the pressure control switch signal for high pressure or medium pressure is "1" and the start-up switch signal for gas turbine is "0", or when the pressure control switch signal for high pressure or medium pressure is "0" and the start-up switch signal for gas turbine is "1", the output of the switching module is set to 0%; and the value of the set value of the pressure before the high pressure steam valve and the starting pressure is calculated by the PID module is compared to obtain the high pressure bypass valve opening control command.

[0017] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0018] This invention provides a high-voltage bypass control system for the gas turbine startup process. It employs a control logic system to present the technical approach of this invention. This system can be deployed and developed in the industrial control systems of various power plant manufacturers. The system includes two control modes. Through a modular judgment method, it can automatically identify the bypass operation state under different operating conditions. After judgment by the selection module, it is engaged in different control loops, effectively taking into account both the current state of the gas turbine and the pressure control engagement state of the high and medium pressure systems. This satisfies the flexible application and deployment requirements of the high-voltage bypass control system during the gas turbine startup process.

[0019] This invention provides a high-pressure bypass control method for gas turbine startup, employing a combination of two control modes to ensure the stability of the high-pressure bypass during startup. This method considers the equipment characteristics under various operating conditions and is applicable not only to power plant DCS control systems but also to PLCs, advanced algorithm controllers, and other equipment. It simultaneously achieves the goals of flexible control, high efficiency, and strong system adaptability. This invention enables fully automated control, reducing the workload of operators and serving various types of two-on-one gas-fired combined cycle units.

[0020] In summary, the high-pressure bypass control system and method for gas turbine startup described in this invention, through a deep understanding and rational application of the high-pressure bypass control system, can significantly improve the startup efficiency and operational stability of the unit, thereby ensuring the reliability and economy of power supply. This invention solves the problem of poor adjustment effect of the high-pressure bypass valve during gas turbine startup and steam connection, significantly improving the startup efficiency and operational stability of the unit, and meeting the requirements for fully automated control of the high-pressure bypass process. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the high-pressure bypass control principle during the gas turbine startup process.

[0022] Explanation of reference numerals in the attached figures:

[0023] 001 indicates that the pressure control for high or medium pressure is not engaged; 002 indicates that the gas turbine has started; 003 indicates that the setpoint is 10%; 004 indicates that the setpoint is 0%; 005 indicates the pressure before the high-pressure steam valve; 006 indicates the start-up pressure setpoint; 007 indicates the AND module; 008 indicates the switching module; 009 indicates the rate limiting module; 010 indicates the small selection module; 011 indicates the PID module; 012 indicates the large selection module; and 013 indicates the high-pressure bypass valve opening control command. Detailed Implementation

[0024] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0025] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0027] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0028] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0029] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0030] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0031] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0032] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0033] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0034] Example 1

[0035] like Figure 1 As shown, this embodiment provides a high-pressure bypass control system for the gas turbine startup process, including an interface module 007, a switching module 008, a rate limiting module 009, a small selection module 010, a PID module 011, and a large selection module 012. The output terminal of the interface module 007 is connected to the input terminal of the switching module 008, the output terminal of the rate limiting module 009 is connected to the input terminal of the small selection module 010, the output terminals of the small selection module 010 are respectively connected to the input terminals of the PID module 011, and the output terminals of the switching module 008 and the PID module 011 are both connected to the input terminal of the large selection module 012.

[0036] In this embodiment, the input terminal of module 007 is connected to a switch input signal indicating that the high-pressure or medium-pressure control is not engaged (001) and a switch input signal indicating that the gas turbine has started (002).

[0037] In this embodiment, the input terminal of the switching module 008 is also connected to an analog input signal 003 with a set value of 10%.

[0038] In this embodiment, the input terminal of the switching module 008 is also connected to an analog input signal 004 when the set value is 0%.

[0039] In this embodiment, the input terminal of the rate limiting module 009 is connected to the analog input signal of the pressure 005 before the high-pressure steam valve.

[0040] In this embodiment, the input terminal of the small selection module 010 is also connected to an analog input signal of the stroke pressure setting value 006.

[0041] In this embodiment, the input terminal of the PID module 011 is also connected to the analog input signal of the pressure 005 before the high-pressure steam valve.

[0042] In this embodiment, the output of the election module 012 is connected to the high-pressure bypass valve opening control command 013.

[0043] In this embodiment, a control logic system is used to present the technical approach of the present invention. This system can be deployed and developed in the industrial control systems of various manufacturers in power plants. The system includes two control modes. Through modular judgment, it can automatically identify the bypass operation status under different operating conditions. After the selection module judges, it is put into different control loops, effectively taking into account both the current state of the gas turbine and the pressure control activation status of the high and medium pressure, thus satisfying the flexible application and deployment of the high-pressure bypass control system during the gas turbine startup process.

[0044] Example 2

[0045] like Figure 1 As shown in the figure, this embodiment provides a high-pressure bypass control method for the gas turbine startup process, including:

[0046] When both the high-pressure or medium-pressure pressure control switch signal (001) and the gas turbine start-up switch signal (002) are "1", the output of the switching module (008) is 10% (003). This output is compared with the values ​​calculated by the PID module (011) for the high-pressure steam valve inlet pressure (005) and the start-up pressure setpoint (006), resulting in the high-pressure bypass valve opening control command (013). This embodiment, through a deep understanding and reasonable application of the high-pressure bypass control system, can significantly improve the unit's start-up efficiency and operational stability, thereby ensuring the reliability and economy of power supply.

[0047] In this embodiment, when both the pressure control not engaged (001) and the gas turbine started (002) switch signals are "0", or when the pressure control not engaged (001) and the gas turbine started (002) switch signals are "1", or when the pressure control not engaged (001) and the gas turbine started (002) switch signals are "1", the output of the switching module 008 is 0% (004). This is compared with the values ​​calculated by the PID module 011 for the pressure before the high-pressure steam valve (005) and the setpoint for the start-up pressure (006), to obtain the high-pressure bypass valve opening control command (013).

[0048] In this embodiment, a combination of two control modes is employed to ensure the stability of the high-pressure bypass during the gas turbine startup process, taking into account the equipment characteristics under various operating conditions. This method is applicable not only to power plant DCS control systems but also to PLCs, advanced algorithm controllers, and other equipment, while simultaneously achieving the goals of flexible control, high efficiency, and strong system adaptability. This invention enables fully automated control, reduces the workload of operators, and serves various types of two-on-one gas-steam combined cycle units.

[0049] Example 3

[0050] like Figure 1 As shown in the figure, this embodiment provides a high-pressure bypass control system for the gas turbine startup process, comprising:

[0051] 1) On the basis of satisfying conventional control, add control logic for steam connection and steam release to avoid pressure deviation during operation and achieve the goal of steam connection parameters during startup and operation.

[0052] 2) The above Figure 1 Schematic diagram of high-pressure bypass control during gas turbine startup.

[0053] Specifically, it includes: pressure control not engaged for high or medium pressure 001, gas turbine started 002, set value is 10% 003, set value is 0% 004, pressure before high pressure steam valve 005, start-up pressure set value 006, AND module 007, switching module 008, rate limiting module 009, small selection module 010, PID module 011, large selection module 012, high pressure bypass valve opening control command 013.

[0054] Figure 1The control strategy logic diagram includes: the switch input signals 001 (pressure control not engaged for high or medium pressure) and 002 (turbine started) are both connected to the input terminal of module 007. The output terminal of module 007 is connected to the input terminal "S" of switching module 008. The analog input signal 003 (set value 10%) is connected to the input terminal "PV1" of switching module 008, and the analog input signal 004 (set value 0%) is connected to the input terminal "PV2" of switching module 008. The analog input signal of the pressure before the high-pressure steam valve 005 is connected to the input terminal of the rate limiting module 009. The output terminal of the rate limiting module 009 and the analog input signal of the start-up pressure setting 006 are both connected to the input terminal of the small selection module 010. The analog input signal of the pressure before the high-pressure steam valve 005 and the output terminal of the small selection module 010 are respectively connected to the input terminals "PV" and "SP" of PID module 011. The outputs of switching module 008 and PID module 011 are both connected to the input of election module 012. The output of election module 012 is connected to the high-pressure bypass valve opening control command 013.

[0055] Control Mode 1: When both the pressure control signal 001 (high-pressure or medium-pressure) and the gas turbine start signal 002 (gas turbine started) are "1", the output of the switching module 008 (set value 10%) is compared with the values ​​calculated by the PID module 011 for the high-pressure bypass valve pressure 005 and the start-up pressure set value 006, resulting in the high-pressure bypass valve opening control command 013. This control method ensures that the high-pressure bypass valve opening is maintained at at least 10%, and dynamically adjusts the high-pressure bypass valve pressure value in real time.

[0056] Control Mode 2: When both the high-pressure or medium-pressure pressure control switch signal 001 (not engaged) and the gas turbine start-up switch signal 002 are "0", or when the high-pressure or medium-pressure pressure control switch signal 001 is "1" and the gas turbine start-up switch signal 002 is "0", or when the high-pressure or medium-pressure pressure control switch signal 001 is "0" and the gas turbine start-up switch signal 002 is "1", the output of the switching module 008 is 004 (set value 004). This value is then compared with the values ​​calculated by the PID module 011 for the high-pressure steam valve inlet pressure 005 and the start-up pressure set value 006 to obtain the high-pressure bypass valve opening control command 013. Therefore, when the unit is in a state where the gas turbine is not started, or the pressure control is engaged at high or medium pressure, this control method meets the requirement that the opening of the high pressure bypass valve must be kept at least 0%, avoiding accidental operation of the high pressure bypass valve, and dynamically adjusting the pressure value in front of the high pressure steam valve in real time, thus meeting the goal of safe and stable operation of the power plant.

[0057] Example 4

[0058] like Figure 1 As shown, this embodiment provides a high-pressure bypass control system for the gas turbine startup process, including an interface module 007, a switching module 008, a rate limiting module 009, a small selection module 010, a PID module 011, and a large selection module 012. The output terminal of the interface module 007 is connected to the input terminal of the switching module 008, the output terminal of the rate limiting module 009 is connected to the input terminal of the small selection module 010, the output terminals of the small selection module 010 are respectively connected to the input terminals of the PID module 011, and the output terminals of the switching module 008 and the PID module 011 are both connected to the input terminal of the large selection module 012.

[0059] In this embodiment, the simulation shows that the No. 1 gas turbine is already running, and the operating parameters of the steam turbine after the No. 2 gas turbine is started are as follows. After applying the present invention, the operating conditions of the load parameters of the No. 1 and No. 2 gas turbines and the turbine load parameters are good, and the bypass control effect is stable.

[0060]

[0061] Example 5

[0062] like Figure 1 As shown, this embodiment provides a high-pressure bypass control system for the gas turbine startup process, including an interface module 007, a switching module 008, a rate limiting module 009, a small selection module 010, a PID module 011, and a large selection module 012. The output terminal of the interface module 007 is connected to the input terminal of the switching module 008, the output terminal of the rate limiting module 009 is connected to the input terminal of the small selection module 010, the output terminals of the small selection module 010 are respectively connected to the input terminals of the PID module 011, and the output terminals of the switching module 008 and the PID module 011 are both connected to the input terminal of the large selection module 012.

[0063] In this embodiment, the simulation shows that the No. 1 gas turbine is already running, and the operating parameters of the No. 2 gas turbine after startup are as follows: after applying the present invention, the operating conditions of parameters such as vacuum, high-pressure cylinder upper and lower temperatures and axial displacement are good, and the bypass control effect is stable.

[0064]

[0065]

[0066] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0067] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method of high pressure bypass control during a start-up process of a combustion engine, characterized in that, The method is based on a high-pressure bypass control system for a gas turbine starting process, which comprises a with module (007), a switching module (008), a rate limiting module (009), a small selection module (010), a PID module (011), and a large selection module (012); the output end of the with module (007) is connected to the input end of the switching module (008), the output end of the rate limiting module (009) is connected to the input end of the small selection module (010), the output end of the small selection module (010) is connected to the input end of the PID module (011), and the output end of the switching module (008) and the output end of the PID module (011) are both connected to the input end of the large selection module (012); The input end of the with module (007) is connected to the analog input signal of the high-pressure or medium-pressure pressure control non-put-in (001) and the on-off input signal of the gas turbine having started (002); The input end of the switching module (008) is also connected to the analog input signal of the set value being 10% (003); The input end of the switching module (008) is also connected to the analog input signal of the set value being 0% (004); The input end of the rate limiting module (009) is connected to the analog input signal of the high-pressure HP turbine valve front pressure (005); The input end of the small selection module (010) is also connected to the analog input signal of the rush rotation pressure set value (006); The input end of the PID module (011) is also connected to the analog input signal of the high-pressure HP turbine valve front pressure (005); The output end of the large selection module (012) is connected to the high-pressure bypass valve opening degree control instruction (013); The method comprises: When the on-off signals of the high-pressure or medium-pressure pressure control non-put-in (001) and the gas turbine having started (002) are both "1", the output of the switching module (008) is the set value being 10% (003), and the values obtained by the high-pressure HP turbine valve front pressure (005) and the rush rotation pressure set value (006) through the PID module (011) are compared by large selection to obtain the high-pressure bypass valve opening degree control instruction (013); When the on-off signals of the high-pressure or medium-pressure pressure control non-put-in (001) and the gas turbine having started (002) are both "0", or the on-off signal of the high-pressure or medium-pressure pressure control non-put-in (001) is "1" and the on-off signal of the gas turbine having started (002) is "0", or the on-off signal of the high-pressure or medium-pressure pressure control non-put-in (001) is "0" and the on-off signal of the gas turbine having started (002) is "1", the output of the switching module (008) is the set value being 0% (004), and the values obtained by the high-pressure HP turbine valve front pressure (005) and the rush rotation pressure set value (006) through the PID module (011) are compared by large selection to obtain the high-pressure bypass valve opening degree control instruction (013).

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