Control system and method for shortening start-stop time of single-shaft gas turbine unit

Abstract

The application discloses a control system and method for shortening the start-stop time of a steam turbine of a single-shaft gas turbine unit, and belongs to the technical field of intelligent control of thermal power plants. The control system and method can realize the start-stop control of the steam turbine of the single-shaft gas turbine unit by adding the control strategy of the interlocking switch of the drain valve before the main steam valve of the steam turbine, and by realizing the opening control mode after the steam temperature before the high-pressure bypass is greater than the steam temperature before the main steam valve by a certain value, the steam temperature reduction caused by the low-temperature steam flow through the pipeline from the high-pressure bypass to the main steam valve due to the early opening of the drain valve is prevented, the time for the rapid increase of the steam temperature before the main steam valve is shortened, and the rapid start-stop control of the steam turbine of the single-shaft gas turbine unit is realized.

Description

Technical Field

[0001] This invention belongs to the field of intelligent control technology for thermal power plants, specifically relating to a control system and method for shortening the start-up and shutdown time of a single-shaft gas turbine unit. Background Technology

[0002] Gas-fired combined cycle units are characterized by fast start-up and shutdown times and timely load response. However, the turbines of single-shaft gas-fired combined cycle units are limited during start-up and shutdown due to the mismatch between the steam temperature and pressure at the turbine's main steam valve and the turbine rotor's temperature rise requirements. This results in increased turbine start-up and warm-up time, preventing the combined cycle unit from fully leveraging its rapid start-up and shutdown advantages. Summary of the Invention

[0003] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a control system and method for shortening the start-up and shutdown time of a single-shaft gas turbine unit.

[0004] To achieve the above objectives, the present invention employs the following technical solution: In a first aspect, embodiments of the present invention provide a control system for shortening the turbine start-up and shutdown time of a single-shaft gas turbine unit, comprising: a high-pressure condensate interlock opening module, a high-pressure condensate interlock closing module, a gas turbine ignition module, a turbine tripping module, a high-pressure main steam outlet temperature module, a main steam temperature module, a main steam valve preheating module, a high-pressure outlet electric valve fully open module, a first control module, a second control module, an automatic condensate valve opening module, and an automatic condensate valve closing module, wherein: The output terminals of the gas turbine ignition module, the steam turbine tripped module, the high-pressure main steam outlet temperature module, the main steam temperature module, and the main steam valve superheat module are respectively connected to the input terminals of the first control module and the second control module. The output terminal of the high-pressure condensate interlock open module is connected to the input terminal of the first control module, and the output terminal of the high-pressure condensate interlock close module is connected to the input terminal of the second control module. The output terminal of the fully open module of the high-exit electric gate is connected to the input terminal of the second control module; The output of the first control module is connected to the input of the automatic drain valve opening module; The output of the second control module is connected to the input of the automatic closing module for the drainage gate.

[0005] In one possible implementation of the first aspect, the first control module includes a first subtraction module, a first greater than module, a first less than module, a first OR module, a second OR module, and a first AND module, wherein: The input terminal of the first subtraction module is connected to the output terminals of the high-pressure main steam outlet temperature module and the main steam temperature module, and the output terminal of the first subtraction module is connected to the input terminal of the first greater than module. The input terminal of the first less module is connected to the output terminal of the steam superheat module in front of the main steam valve; The input of the second OR module is connected to the output of the first less than module and the first greater than module; The output terminals of the second OR module, the turbine tripped module, and the gas turbine ignition module are connected to the input terminal of the first OR module; The input terminal of the first OR module is connected to the output terminal of the first OR module and the high-pressure condensate interlocking module, and the output terminal of the first OR module is connected to the input terminal of the condensate gate automatic opening module.

[0006] In one possible implementation of the first aspect, the second control module includes a second AND module, a second greater than module, a second subtraction module, a second less than module, and a third OR module, wherein: The input terminal of the second subtraction module is connected to the output terminals of the high-pressure main steam outlet temperature module and the main steam temperature module, and the output terminal of the second subtraction module is connected to the input terminal of the second less than module. The output terminal of the steam superheat module in front of the main steam valve is connected to the input terminal of the second superheat module; The output terminals of the second greater than module, the second less than module, the gas turbine ignition module, the steam turbine tripped module, and the high-exit electric door fully open module are connected to the input terminal of the second and module. The input terminal of the third OR module is connected to the output terminal of the second OR module and the high-pressure condensate interlocking module, and the output terminal of the third OR module is connected to the input terminal of the condensate automatic closing module.

[0007] In one possible implementation of the first aspect, the control system further includes a temperature control subsystem, the input of which is connected to the output of the main steam temperature module. The temperature control subsystem is used to verify the output value of the main steam temperature module and control the output value of the main steam temperature module to be higher than a preset threshold.

[0008] In one possible implementation of the first aspect, the temperature control subsystem includes a 100% temperature module for the high-pressure inner cylinder inlet steam turbine casing, a turbine start-up and sequential control module, a main steam temperature all-defect module, a main control valve casing 50% temperature defect module, a third control module, and an X1 criterion satisfaction module, wherein: The output terminals of the high-pressure inner cylinder inlet steam volute 100% temperature module, the steam turbine start-up control step module, the main steam temperature all-defect module, the main control valve shell 50% temperature defect module, and the main steam temperature module are connected to the input terminal of the third control module. The output of the third control module is connected to the input of the module that satisfies the X1 criterion.

[0009] In one possible implementation of the first aspect, the third control module includes a first constant module, an analog input module, a main control valve body 50% temperature module, a first switching module, a first function module, a second function module, a warm-up mode selection module, a second switching module, a third switching module, a third function module, a first addition module, a third greater than module, a fourth greater than module, a third less than module, a third AND module, a second constant module, a fourth switching module, a second addition module, a third addition module, a fifth greater than module, a fourth OR module, a first NOT module, and a fourth AND module, wherein: The output terminals of the first constant module, the main control valve body 50% temperature module, and the analog input module are respectively connected to the Y terminal, N terminal, and enable trigger terminal of the first switching module. The output of the first switching module is connected to the input of the first function module and the second function module, respectively. The output terminals of the first function module, the second function module, and the warm-up mode selection module are respectively connected to the Y terminal, N terminal, and enable trigger terminal of the second switching module; The output terminals of the third switching module, the main steam temperature module, and the main steam temperature all-dead-point module are respectively connected to the Y terminal, N terminal, and enable trigger terminal of the third switching module. The output terminals of the main steam temperature module and the 100% temperature module of the high-pressure inner cylinder inlet steam volute are connected to the input terminal of the first addition module, and the output terminal of the first addition module is connected to the input terminal of the third greater than module. The output of the turbine start-up control module is connected to the input of the fourth greater than module and the third less than module, respectively. The outputs of the third greater than module, the fourth greater than module, and the third less than module are connected to the input of the third less than module. The output terminal of the 100% temperature module of the high-pressure inner cylinder inlet volute is connected to the input terminal of the third function module. The output terminals of the third function module, the second constant module, and the third AND module are respectively connected to the Y terminal, N terminal, and enable trigger terminal of the fourth switching module. The outputs of the third and fourth switching modules are connected to the input of the second addition module; the outputs of the second switching module and the second addition module are connected to the input of the third addition module; and the output of the third addition module is connected to the input of the fifth greater than module. The output terminals of the main steam temperature full failure module and the main control valve body 50% temperature full failure module are connected to the input terminal of the fourth OR module, and the output terminal of the fourth OR module is connected to the input terminal of the first non-module. The outputs of the fifth greater than module and the first non-module are connected to the input of the fourth AND module, and the output of the fourth AND module is connected to the input of the X1 criterion satisfying module.

[0010] In one possible implementation of the first aspect, the control system further includes a trip control subsystem, the input of which is connected to the output of the main steam temperature module, and the trip control subsystem is used to control the turbine to trip based on the output value of the main steam temperature module and the pressure condition.

[0011] In one possible implementation of the first aspect, the trip control subsystem includes a high-pressure cylinder exhaust temperature module, a high-pressure regulating valve downstream pressure module, a high-pressure bypass valve position module, a mid-pressure bypass valve position module, a fourth control module, and a module that satisfies the turbine tripping conditions, wherein: The output terminals of the high-pressure cylinder exhaust temperature module, the high-pressure regulating valve downstream pressure module, the high-pressure bypass valve position module, and the intermediate bypass valve position module are connected to the input terminal of the fourth control module. The output terminal of the fourth control module is connected to the input terminal of the module that meets the turbine tripping conditions.

[0012] In one possible implementation of the first aspect, the fourth control module includes a sixth greater than module, a fourth less than module, a fifth OR module, a first less than module, a seventh greater than module, and a fifth AND module, wherein: The output value of the high-pressure cylinder exhaust temperature module is determined based on the output value of the main steam temperature module, and the output terminal of the high-pressure cylinder exhaust temperature module is connected to the input terminal of the sixth module. The output terminal of the high-pressure module after the high-pressure valve is connected to the input terminal of the fourth less-than module; The input of the fifth OR module is connected to the output of the sixth greater than module and the fourth less than module; The input terminal of the first sub-select module is connected to the output terminals of the high bypass valve position module and the middle bypass valve position module, and the output terminal of the first sub-select module is connected to the input terminal of the seventh greater than module. The input terminal of the fifth AND module is connected to the output terminals of the fifth OR module and the seventh greater than module, and the output terminal of the fifth AND module is connected to the input terminal of the module that satisfies the turbine tripping condition.

[0013] Secondly, embodiments of the present invention provide a control method for shortening the start-up and shutdown time of a single-shaft gas turbine unit, comprising the following steps: The first control module processes and obtains the output value based on the output values ​​of the high-pressure condensate interlock opening module, the gas turbine ignition module, the turbine tripping module, the high-pressure main steam outlet temperature module, the main steam temperature module, and the main steam valve superheat module. The second control module processes and obtains the output values ​​based on the output values ​​of the high-pressure condensate interlock module, the gas turbine ignition module, the turbine tripped module, the high-pressure outlet electric valve fully open module, the main steam valve front steam superheat module, the high-pressure main steam outlet temperature module, and the main steam temperature module. The automatic opening module of the drain valve outputs the output value according to the output value of the first control module to realize the opening control of the drain valve; The automatic closing module of the drain valve outputs the output value based on the output value of the second control module to realize the closing control of the drain valve.

[0014] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a control system and method for shortening the start-up and shutdown time of a single-shaft gas turbine unit. This system, by adding a control strategy to the interlock switch of the drain valve before the main steam valve, can achieve a control mode where the control is activated only after the steam temperature before the high-pressure bypass exceeds a certain value above the steam temperature before the main steam valve. This prevents the drain valve from opening too early, which could cause the steam temperature in the pipeline from the high-pressure bypass to the main steam valve to drop too quickly due to the flow of low-temperature steam. This shortens the time required for the steam temperature before the main steam valve to rise rapidly, thus achieving rapid start-up and shutdown control of the turbine in the single-shaft gas turbine unit. Attached Figure Description

[0015] Figure 1 A schematic diagram of the control system for shortening turbine start-up and shutdown time in a single-shaft gas turbine unit provided in an embodiment of the present invention; Figure 2 A schematic diagram illustrating an application scenario of the control system for shortening turbine start-up and shutdown time in a single-shaft gas turbine unit provided in an embodiment of the present invention; Figure 3 A schematic diagram of the temperature control subsystem in the control system for shortening turbine start-up and shutdown time of a single-shaft gas turbine unit provided in an embodiment of the present invention; Figure 4 A schematic diagram of the trip control subsystem in the control system for shortening turbine start-up and shutdown time of a single-shaft gas turbine unit provided in an embodiment of the present invention; Figure 5 A schematic diagram comparing the changes in high-pressure main steam outlet temperature and main steam temperature collected for the implementation of this invention with existing technologies. Figure 6 A schematic diagram comparing the changes in high-pressure cylinder inlet pressure, high bypass degree, medium bypass degree, and turbine trip curve collected for the implementation of this invention with the prior art. Among them: 001-High-pressure main steam outlet temperature module; 002-High-pressure bypass desuperheating water; 003-High-pressure bypass desuperheating water pneumatic isolation valve; 004-High-pressure bypass desuperheating water regulating valve; 005-High-pressure bypass valve; 006-High-pressure main steam valve inlet pneumatic drain valve 1; 007-Main steam warming pipe drain valve 1; 008-High-pressure main steam valve inlet pneumatic drain valve 2; 009-Main steam temperature module; 010-Main steam valve inlet superheat module; 011-Main regulating valve housing 50% temperature module; 012-High-pressure inner cylinder inlet steam turbine housing 100% temperature module; 013-High-pressure cylinder module; 014-High-pressure drain interlock opening module; 015-Gas turbine Ignition module; 016-Turbine tripped module; 017-First subtraction module; 018-First greater than module; 019-First less than module; 020-Second OR module; 021-First AND module; 022-First OR module; 023-Automatic drain valve opening module; 024-High-pressure drain interlock closing module; 025-High-pressure outlet electric door fully open module; 026-Second AND module; 027-Second subtraction module; 028-Second less than module; 029-Second AND module; 030-Third OR module; 031-Automatic drain valve closing module; 032-First constant module; 033-Analog Input Module; 034-First Switching Module; 035-First Function Module; 036-Second Function Module; 037-Warm-up Mode Selection Module; 038-Second Switching Module; 039-Third Switching Module; 040-Main Steam Temperature All-Dead-Point Module; 041-Third Function Module; 042-First Addition Module; 043-Third Greater Than Module; 044-Steam Turbine Start-up Sequential Control Step Module; 045-Fourth Greater Than Module; 046-Third Less Than Module; 047-Third AND Module; 048-Second Constant Module; 049-Fourth Switching Module; 050-Second Addition Module; 051-Third Addition module; 052 - Fifth Greater Than Module; 053 - Main Control Valve Shell 50% Temperature Failure Module; 054 - Fourth OR Module; 055 - First NOT Module; 056 ​​- Fourth AND Module; 057 - X1 Criterion Satisfaction Module; 058 - High Pressure Cylinder Exhaust Temperature Module; 059 - Sixth Greater Than Module; 060 - High Control Valve Post-Pressure Module; 061 - Fourth Less Than Module; 062 - Fifth OR Module; 063 - High Bypass Valve Position Module; 064 - Medium Bypass Valve Position Module; 065 - First Small Selection Module; 066 - Seventh Greater Than Module; 067 - Fifth AND Module; 068 - Steam Turbine Trip Condition Satisfaction Module. Detailed Implementation

[0016] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0017] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0018] The present invention will now be described in further detail with reference to the accompanying drawings: Example 1 See appendix Figure 1 The present invention provides a control system for shortening the start-up and shutdown time of a single-shaft gas turbine unit, comprising: a high-pressure condensate interlock opening module 014, a high-pressure condensate interlock closing module 024, a gas turbine ignition module 015, a turbine tripped module 016, a high-pressure main steam outlet temperature module 001, a main steam temperature module 009, a main steam valve preheating module 010, a high-pressure outlet electric valve fully open module 025, a first control module, a second control module, a condensate valve automatic opening module 023, and a condensate valve automatic closing module 031, wherein: The output terminals of the gas turbine ignition module 015, the steam turbine tripped module 016, the high-pressure main steam outlet temperature module 001, the main steam temperature module 009, and the main steam valve front steam superheat module 010 are respectively connected to the input terminals of the first control module and the second control module. The output terminal of the high-pressure condensate interlock open module 014 is connected to the input terminal of the first control module, and the output terminal of the high-pressure condensate interlock close module 024 is connected to the input terminal of the second control module. The output terminal of the fully open module 025 of the high-exit electric gate is connected to the input terminal of the second control module; The output of the first control module is connected to the input of the automatic drain valve opening module 023; The output of the second control module is connected to the input of the automatic closing module 031 for the drainage gate.

[0019] In this embodiment, by adding a control strategy to the interlock switch of the steam trap in front of the turbine main steam valve, the control mode can be activated only after the steam temperature in front of the high-pressure bypass is greater than a certain value of the steam temperature in front of the main steam valve. This prevents the steam temperature from dropping too quickly due to the low-temperature steam flow in the pipeline from the high-pressure bypass to the main steam valve caused by premature opening of the steam trap, shortens the time for the steam temperature in front of the main steam valve to rise rapidly, and realizes rapid start-up and shutdown control of the turbine of the single-shaft gas turbine unit.

[0020] The control method for shortening turbine start-up and shutdown time in a single-shaft gas turbine unit using the aforementioned system includes the following steps: The first control module processes and obtains the output value based on the output values ​​of the high-pressure condensate interlocking module 014, the gas turbine ignition module 015, the turbine tripped module 016, the high-pressure main steam outlet temperature module 001, the main steam temperature module 009, and the main steam valve front steam superheat module 010. The second control module processes and obtains the output values ​​based on the output values ​​of the high-pressure condensate interlock module 024, the gas turbine ignition module 015, the turbine tripped module 016, the high-pressure outlet electric valve fully open module 025, the main steam valve front steam superheat module 010, the high-pressure main steam outlet temperature module 025, and the main steam temperature module 009. The automatic drain valve opening module 023 outputs the output value based on the output value of the first control module to realize the opening control of the drain valve; The automatic closing module 031 of the drain valve outputs the output value of the second control module to realize the closing control of the drain valve.

[0021] The application scenarios of this invention are as follows: Figure 2 As shown, it specifically includes: a high-pressure main steam outlet temperature module 001 (for acquiring the high-pressure main steam outlet temperature CT1), a high-pressure bypass desuperheating water module 002, a high-pressure bypass desuperheating water pneumatic isolation valve 003, a high-pressure bypass desuperheating water regulating valve 004, a high-pressure bypass valve 005, a high-pressure main steam valve inlet pneumatic drain valve 1006, a main steam warming pipe drain valve 1007, a high-pressure main steam valve inlet pneumatic drain valve 2008, a main steam temperature module 009 (for acquiring the main steam temperature CT2), a main steam valve inlet steam superheating module 010 (for acquiring the main steam valve inlet steam superheating CT3), a main regulating valve body 50% temperature module 011, a high-pressure inner cylinder inlet steam volute 100% temperature module 012, and a high-pressure cylinder 013. By acquiring the high-pressure main steam outlet temperature, the main steam temperature, and the main steam valve inlet steam superheating, the steam temperature difference and the corresponding saturated superheat are calculated. The drain valve is then controlled based on the opening and closing status of the high-pressure main steam outlet valve.

[0022] In one embodiment, the first control module includes a first subtraction module 017, a first greater than module 018, a first less than module 019, a first OR module 022, a second OR module 020, and a first AND module 021, wherein: The input terminal of the first subtraction module 017 is connected to the output terminals of the high-pressure main steam outlet temperature module 001 and the main steam temperature module 009, and the output terminal of the first subtraction module 017 is connected to the input terminal of the first greater than module 018. The input terminal of the first less than module 019 is connected to the output terminal of the main steam valve front steam superheat module 010; The input terminal of the second OR module 020 is connected to the output terminals of the first less than module 019 and the first greater than module 018; The output terminals of the second OR module 020, the steam turbine tripped module 016, and the gas turbine ignition module 015 are connected to the input terminal of the first OR module 021. The input terminal of the first OR module 022 is connected to the output terminals of the first OR module 021 and the high-pressure condensate interlocking module 014, and the output terminal of the first OR module 022 is connected to the input terminal of the condensate gate automatic opening module 023.

[0023] In one embodiment, the second control module includes a second AND module 029, a second greater than module 026, a second subtraction module 027, a second less than module 028, and a third OR module 030, wherein: The input terminal of the second subtraction module 027 is connected to the output terminals of the high-pressure main steam outlet temperature module 001 and the main steam temperature module 009, and the output terminal of the second subtraction module 027 is connected to the input terminal of the second less module 028. The output terminal of the main steam valve front steam superheat module 010 is connected to the input terminal of the second superheat module 026; The output terminals of the second greater than module 026, the second less than module 028, the gas turbine ignition module 015, the steam turbine tripped module 016, and the high-exit electric door fully open module 025 are connected to the input terminal of the second and module 029. The input terminal of the third OR module 030 is connected to the output terminals of the second OR module 029 and the high-pressure condensate interlocking module 024, and the output terminal of the third OR module 030 is connected to the input terminal of the condensate gate automatic closing module 031.

[0024] Example 2 See appendix Figure 3 The present invention provides a control system for shortening the start-up and shutdown time of a single-shaft gas turbine unit. The control system further includes a temperature control subsystem. The input terminal of the temperature control subsystem is connected to the output terminal of the main steam temperature module 009. The temperature control subsystem is used to verify the output value of the main steam temperature module and control the output value of the main steam temperature module 009 to be higher than a preset threshold.

[0025] In practical implementation, if the temperature of the incoming main steam is lower than the metal temperature of the valve body, the valve body will be rapidly cooled, generating excessive thermal stress and even causing equipment damage. To avoid this damage and reduce the waiting time for the main steam temperature to rise before the turbine control valve opens, temperature control can be performed in advance. This invention adopts the X1 criterion, namely: the temperature control subsystem includes a 100% temperature module 012 for the high-pressure inner cylinder inlet volute, a turbine start-up control step module 044, a main steam temperature failure point module 040, a 50% temperature failure point module 053 for the main control valve housing, a third control module, and an X1 criterion satisfaction module 057, wherein: The output terminals of the high-pressure inner cylinder inlet steam volute 100% temperature module 012, the steam turbine start-up control step module 044, the main steam temperature all-defect module 040, the main control valve shell 50% temperature defect module 053, and the main steam temperature module 009 are connected to the input terminal of the third control module. The output of the third control module is connected to the input of module 057, which satisfies the X1 criterion.

[0026] In practical implementation, from the turbine's sequential start-up to before it reaches full speed, the main steam valve inlet temperature is dynamically adapted to the X1 criterion based on the turbine's high-pressure rotor temperature, compressing the waiting time for the main steam valve inlet temperature to rise before the turbine's regulating valve opens. The X1 criterion is defined as: limiting the lower limit of the main steam temperature to ensure it is higher than the high-pressure regulating valve body temperature by a certain value (i.e., main steam temperature > high-pressure regulating valve body temperature + X1 setpoint). This is used before turbine start-up to determine whether opening the main steam valve for a warm-up check of the high-pressure regulating valve is permissible, preventing the high-pressure regulating valve from cooling down. Specifically: The third control module includes a first constant module 032, an analog input module 033, a main control valve body 50% temperature module 011, a first switching module 034, a first function module 035, a second function module 036, a warm-up mode selection module 037, a second switching module 038, a third switching module 039, a third function module 041, a first addition module 042, a third greater than module 043, a fourth greater than module 045, a third less than module 046, a third AND module 047, a second constant module 048, a fourth switching module 049, a second addition module 050, a third addition module 051, a fifth greater than module 052, a fourth OR module 054, a first NOT module 055, and a fourth AND module 056, wherein: The output terminals of the first constant module 032, the main control valve body 50% temperature module 011, and the analog input module 033 are respectively connected to the Y terminal, N terminal, and enable trigger terminal of the first switching module 034. The output of the first switching module 034 is connected to the input of the first function module 035 and the second function module 036, respectively. The output terminals of the first function module 035, the second function module 036, and the warm-up mode selection module 037 are respectively connected to the Y terminal, N terminal, and enable trigger terminal of the second switching module 038. The output terminals of the third switching module 039, the main steam temperature module 009, and the main steam temperature all-dead-point module 040 are respectively connected to the Y terminal, N terminal, and enable trigger terminal of the third switching module 039. The output terminals of the main steam temperature module 009 and the high-pressure inner cylinder inlet steam volute 100% temperature module 012 are connected to the input terminal of the first addition module 042, and the output terminal of the first addition module 042 is connected to the input terminal of the third greater module 043. The output of the turbine start-up control module 044 is connected to the input of the fourth greater module 045 and the third less module 046 respectively. The outputs of the third greater module 043, the fourth greater module 045 and the third less module 046 are connected to the input of the third less module 047. The output terminal of the 100% temperature module 012 for the high-pressure inner cylinder inlet volute is connected to the input terminal of the third function module 041. The output terminals of the third function module 041, the second constant module 048, and the third AND module 047 are respectively connected to the Y terminal, N terminal, and enable trigger terminal of the fourth switching module 049. The output terminals of the third switching module 039 and the fourth switching module 049 are connected to the input terminal of the second adding module 050. The output terminals of the second switching module 038 and the second adding module 050 are connected to the input terminal of the third adding module 051. The output terminal of the third adding module 051 is connected to the input terminal of the fifth greater than module 052. The output terminals of the main steam temperature full failure module 040 and the main control valve body 50% temperature full failure module 053 are connected to the input terminal of the fourth OR module 054, and the output terminal of the fourth OR module 054 is connected to the input terminal of the first non-module 055. The output terminals of the fifth greater than module 052 and the first non-module 055 are connected to the input terminal of the fourth AND module 056, and the output terminal of the fourth AND module 056 is connected to the input terminal of the X1 criterion satisfying module 057.

[0027] Example 3 See appendix Figure 4 The present invention provides a control system for shortening the start-up and shutdown time of a single-shaft gas turbine unit. The control system also includes a trip control subsystem. The input terminal of the trip control subsystem is connected to the output terminal of the main steam temperature module 009. The trip control subsystem is used to control the turbine to trip according to the output value of the main steam temperature module 009 and the pressure condition.

[0028] In practical implementation, turbine sequential shutdown typically occurs when the high-pressure cylinder exhaust temperature rises to a certain value or the load reduction margin is insufficient. This poses risks such as long turbine shutdown waiting times and the high high-pressure cylinder exhaust temperature affecting the safety of the last-stage blades. This invention provides a bypass control-based strategy, where the trip control subsystem includes a high-pressure cylinder exhaust temperature module 058, a high-pressure regulating valve downstream pressure module 060, a high-pressure bypass valve position module 063, a mid-pressure bypass valve position module 064, a fourth control module, and a module 068 that satisfies the turbine trip conditions. The output terminals of the high-pressure cylinder exhaust temperature module 058, the high-pressure regulating valve downstream pressure module 060, the high-pressure bypass valve position module 063, and the intermediate bypass valve position module 064 are connected to the input terminal of the fourth control module, and the output terminal of the fourth control module is connected to the input terminal of the turbine tripping condition module 068.

[0029] In practical implementation, based on the bypass control strategy, under the premise that the steam flow rate of the waste heat boiler is sufficient, the turbine is automatically tripped when the high-pressure cylinder inlet steam pressure is less than a certain value, thereby reducing downtime and avoiding the risk of excessive increase in high-pressure cylinder exhaust temperature. Specifically: the fourth control module includes the sixth greater than module 059, the fourth less than module 061, the fifth OR module 062, the first less than module 065, the seventh greater than module 066, and the fifth AND module 067, wherein: The output value of the high-pressure cylinder exhaust temperature module 058 is determined based on the output value of the main steam temperature module 009. The output terminal of the high-pressure cylinder exhaust temperature module 058 is connected to the input terminal of the sixth module 059. The output terminal of the high-pressure regulating valve downstream pressure module 060 is connected to the input terminal of the fourth less-than module 061; The input terminal of the fifth OR module 062 is connected to the output terminals of the sixth greater than module 059 and the fourth less than module 061; The input terminal of the first sub-selection module 065 is connected to the output terminals of the high bypass valve position module 063 and the middle bypass valve position module 064, and the output terminal of the first sub-selection module 065 is connected to the input terminal of the seventh greater than module 066. The input terminal of the fifth AND module 067 is connected to the output terminals of the fifth OR module 062 and the seventh greater than module 066, and the output terminal of the fifth AND module 067 is connected to the input terminal of the module 068 that satisfies the turbine tripping conditions.

[0030] See appendix Figure 1 - Appendix Figure 4 The principle of the control method of the present invention can be further described in the following steps: 1) Real-time acquisition of key parameters such as the high-pressure main steam outlet temperature module 001, main steam temperature module 009, main steam valve inlet steam temperature module 010, main control valve body 50% temperature module 011, and high-pressure inner cylinder inlet steam volute 100% temperature module 012. By calculating that the control mode only opens after the high-pressure bypass steam temperature exceeds a certain value above the main steam valve inlet steam temperature, it avoids excessively rapid decreases in main steam temperature caused by low-temperature steam flow in the pipeline, thus shortening the time for rapid temperature rise at the main steam valve inlet.

[0031] 2) The high-pressure main steam outlet temperature CT1 and main steam temperature CT2 collected in step 1 are sent to the first subtraction module 017 for subtraction calculation to obtain the temperature difference between the furnace side and the turbine side. The difference is sent to the first greater than module 018 for comparison calculation. At the same time, the main steam valve inlet steam temperature CT3 is sent to the first less than module 019 for comparison calculation. The results of the two comparison calculations are sent to the second OR module 020. The output value of the second OR module 020 is sent to the first AND module 021 along with the output values ​​of the gas turbine ignition module 015 and the turbine tripped module 016, respectively. The output value of the first AND module 021 is sent to the first OR module 022 along with the output value of the high-pressure drain interlock opening module 014. Finally, the drain valve automatic opening module 023 outputs the drain valve automatic opening command according to the output value of the first OR module 022.

[0032] The main steam valve inlet steam temperature CT3 is sent to the second greater than module 026 for comparison calculation; at the same time, the high-pressure main steam outlet temperature CT1 and the main steam temperature CT2 are sent to the second subtraction module 027 for subtraction calculation, and the output value is sent to the second less than module 028 for comparison calculation; the results of the two comparison calculations, the output values ​​of the gas turbine ignition module 015, the turbine tripped module 016, and the high-pressure outlet electric valve fully open module 025 are respectively sent to the second AND module 029, and the output result obtained from the second AND module 029 and the high-pressure drain interlock module 024 are sent to the third OR module 030. Finally, the drain valve automatic closing module 031 outputs the drain valve automatic closing command according to the output value of the third OR module 030.

[0033] 3) The first constant module 032 and the main regulating valve body 50% temperature module 011 are respectively connected to the Y and N terminals of the first switching module 034. The simulation input module 033 is connected to the enable trigger terminal of the first switching module 034. When the simulation input module 033 is not triggered, the main regulating valve body 50% temperature module 011 is nonlinearly corrected by the first function module 035 and the second function module 036, and then switched by the warm-up mode selection module 037. The main steam temperature module 009 is connected to the N terminal of the third switching module 039, the main steam temperature all-dead-point module 040 is connected to the enable trigger terminal of the third switching module 039, and the output terminal of the third switching module 039 is connected to the Y terminal of the third switching module 039 and the second addition module 040, respectively. 50. When the main steam temperature is completely off, the current value output is locked; the high-pressure inner cylinder inlet steam volute 100% temperature module 012 is connected to the Y end of the fourth switching module 049 after nonlinear correction by the third function module 041, and the second constant module 048 is connected to the N end of the fourth switching module 049; the main steam temperature module 009 and the high-pressure inner cylinder inlet steam volute 100% temperature module 012 are sent to the first addition module 042 for deviation calculation, and the deviation value is compared and calculated by the third greater than module 043; the turbine start-up sequence control step module 044 is sent to the fourth greater than module 045 and the third less than module 046 for comparison and calculation respectively; the output values ​​of the two and the output value of the third greater than module 043 are sent to the third and module 047 as the trigger end of the fourth switching module 049. The output values ​​of the third switching module 039 and the fourth switching module 049 are sent to the second addition module 050 for addition. The resulting value is then sent to the third addition module 051 for subtraction and compared with the fifth greater than module 052. The main steam temperature full bad point module 040 and the main control valve shell 50% temperature bad point module 053 are sent to the fourth OR module 054 for OR judgment, and the output value is sent to the first NOT module 055. The output value of the fifth greater than module 052 and the output value of the first NOT module 055 are sent to the fourth AND module 056 for AND judgment, and finally, the X1 satisfies condition module 057 outputs the result.

[0034] 4) The high-pressure cylinder exhaust temperature module 058 sends the data to the sixth greater than module 059 for comparison; the high-pressure regulating valve downstream pressure module 060 sends the data to the fourth less than module 061 for comparison; the outputs of both are sent to the fifth OR module 062 for OR judgment; the high-pressure bypass valve position module 063 and the medium-pressure bypass valve position module 064 send the data to the first smaller selection module 065 for smaller operation, and the resulting output value is connected to the seventh greater than module 066 for comparison; the outputs of the fifth OR module 062 and the seventh greater than module 066 are respectively connected to the fifth AND module 067 for AND judgment, and the turbine trip condition module 068 executes the final output.

[0035] In summary, the control system and method provided by the embodiments of the present invention for shortening the turbine start-up and shutdown time of a single-shaft gas turbine unit solves the problem that the temperature of the waste heat boiler steam and the steam temperature before the main steam valve of the turbine cannot rise in time during the start-up phase due to insufficient steam flow; and solves the problem of excessively long turbine shutdown time during the turbine shutdown phase by coordinating the high-pressure cylinder inlet steam pressure and bypass flow. This achieves both shortening the turbine start-up and shutdown time of the single-shaft gas turbine unit and improving the reliability of the turbine's safe and stable operation.

[0036] See appendix Figure 5 Appendix Figure 6 The figures show a comparison of the changes in high-pressure main steam outlet temperature and main steam temperature collected during the implementation of this invention with existing technologies, as well as a comparison of the changes in high-pressure cylinder inlet pressure, high bypass degree, medium bypass degree, and turbine trip curve with existing technologies. It is easy to see from the figures that: Figure 1 During the same stage T0 to T1, the control valve is opened, and the steam flow rate before the main steam valve increases. This increased flow rate leads to a faster rate of temperature rise in the main steam and high-pressure main steam outlet temperatures during the same stage T2 to T3, quickly reaching the X1 criterion and achieving rapid temperature increase, thereby shortening the turbine start-up time. (Appendix) Figure 2 Provided that the steam flow rate of the waste heat boiler is sufficient, the shutdown time can be shortened by opening the bypass in advance, thus advancing the shutdown period from T1 to T0, thereby reducing the shutdown time and avoiding the risk of excessively high exhaust temperature of the high-pressure cylinder.

[0037] 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 to the technical solution 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 control system for shortening turbine start-up and shutdown time in a single-shaft gas turbine unit, characterized in that, include: The system includes: a high-pressure condensate drain interlock opening module, a high-pressure condensate drain interlock closing module, a gas turbine ignition module, a turbine tripped module, a high-pressure main steam outlet temperature module, a main steam temperature module, a main steam valve preheating module, a high-pressure outlet electric valve fully open module, a first control module, a second control module, an automatic condensate drain opening module, and an automatic condensate drain closing module. Among these: The output terminals of the gas turbine ignition module, the steam turbine tripped module, the high-pressure main steam outlet temperature module, the main steam temperature module, and the main steam valve superheat module are respectively connected to the input terminals of the first control module and the second control module. The output terminal of the high-pressure hydrophobic interlock open module is connected to the input terminal of the first control module, and the output terminal of the high-pressure hydrophobic interlock close module is connected to the input terminal of the second control module. The output terminal of the fully open module of the high-exit electric door is connected to the input terminal of the second control module; The output terminal of the first control module is connected to the input terminal of the automatic opening module of the drainage gate; The output of the second control module is connected to the input of the automatic closing module of the drainage gate.

2. The control system for shortening turbine start-up and shutdown time in a single-shaft gas turbine unit according to claim 1, characterized in that, The first control module includes a first subtraction module, a first greater than module, a first less than module, a first OR module, a second OR module, and a first AND module, wherein: The input terminal of the first subtraction module is connected to the output terminals of the high-pressure main steam outlet temperature module and the main steam temperature module, and the output terminal of the first subtraction module is connected to the input terminal of the first greater module. The input terminal of the first less module is connected to the output terminal of the main steam valve front steam superheat module; The input terminal of the second OR module is connected to the output terminals of the first less than module and the first greater than module; The output terminals of the second OR module, the turbine tripped module, and the gas turbine ignition module are connected to the input terminal of the first OR module; The input terminal of the first OR module is connected to the output terminal of the first OR module and the high-pressure condensate interlocking opening module, and the output terminal of the first OR module is connected to the input terminal of the condensate gate automatic opening module.

3. The control system for shortening turbine start-up and shutdown time in a single-shaft gas turbine unit according to claim 1, characterized in that, The second control module includes a second AND module, a second greater than module, a second subtraction module, a second less than module, and a third OR module, wherein: The input terminal of the second subtraction module is connected to the output terminals of the high-pressure main steam outlet temperature module and the main steam temperature module, and the output terminal of the second subtraction module is connected to the input terminal of the second less than module. The output terminal of the main steam valve front steam superheat module is connected to the input terminal of the second superheat module; The output terminals of the second greater than module, the second less than module, the gas turbine ignition module, the steam turbine tripped module, and the high-voltage outlet electric valve fully open module are connected to the input terminal of the second greater module; The input terminal of the third OR module is connected to the output terminals of the second OR module and the high-pressure condensate interlocking module, and the output terminal of the third OR module is connected to the input terminal of the condensate gate automatic closing module.

4. The control system for shortening turbine start-up and shutdown time in a single-shaft gas turbine unit according to claim 1, characterized in that, The control system further includes a temperature control subsystem. The input terminal of the temperature control subsystem is connected to the output terminal of the main steam temperature module. The temperature control subsystem is used to verify the output value of the main steam temperature module and control the output value of the main steam temperature module to be higher than a preset threshold.

5. The control system for shortening turbine start-up and shutdown time in a single-shaft gas turbine unit according to claim 4, characterized in that, The temperature control subsystem includes a 100% temperature module for the high-pressure inner cylinder inlet steam turbine casing, a turbine start-up and sequential control module, a main steam temperature all-failure module, a main control valve casing 50% temperature failure module, a third control module, and an X1 criterion satisfaction module, wherein: The output terminals of the high-pressure inner cylinder inlet steam turbine casing 100% temperature module, the turbine start-up control step module, the main steam temperature all-defect module, the main control valve casing 50% temperature defect module, and the main steam temperature module are connected to the input terminal of the third control module. The output of the third control module is connected to the input of the X1 criterion satisfaction module.

6. The control system for shortening turbine start-up and shutdown time in a single-shaft gas turbine unit according to claim 5, characterized in that, The third control module includes a first constant module, a simulation input module, a main control valve body 50% temperature module, a first switching module, a first function module, a second function module, a warm-up mode selection module, a second switching module, a third switching module, a third function module, a first addition module, a third greater than module, a fourth greater than module, a third less than module, a third AND module, a second constant module, a fourth switching module, a second addition module, a third addition module, a fifth greater than module, a fourth OR module, a first NOT module, and a fourth AND module, wherein: The output terminals of the first constant module, the main control valve body 50% temperature module, and the analog input module are respectively connected to the Y terminal, N terminal, and enable trigger terminal of the first switching module. The output of the first switching module is connected to the input of the first function module and the second function module, respectively; The output terminals of the first function module, the second function module, and the warm-up mode selection module are respectively connected to the Y terminal, N terminal, and enable trigger terminal of the second switching module; The output terminals of the third switching module, the main steam temperature module, and the main steam temperature all-dead-point module are respectively connected to the Y terminal, N terminal, and enable trigger terminal of the third switching module. The output terminals of the main steam temperature module and the 100% temperature module of the high-pressure inner cylinder inlet steam volute are connected to the input terminal of the first addition module, and the output terminal of the first addition module is connected to the input terminal of the third greater module. The output terminal of the turbine start-up control module is connected to the input terminals of the fourth greater module and the third less module, respectively, and the output terminals of the third greater module, the fourth greater module, and the third less module are connected to the input terminal of the third greater module. The output terminal of the high-pressure inner cylinder inlet volute 100% temperature module is connected to the input terminal of the third function module. The output terminals of the third function module, the second constant module, and the third AND module are respectively connected to the Y terminal, N terminal, and enable trigger terminal of the fourth switching module. The output terminals of the third switching module and the fourth switching module are connected to the input terminal of the second adding module, the output terminals of the second switching module and the second adding module are connected to the input terminal of the third adding module, and the output terminal of the third adding module is connected to the input terminal of the fifth greater than module. The output terminals of the main steam temperature full failure module and the main control valve body 50% temperature full failure module are connected to the input terminal of the fourth OR module, and the output terminal of the fourth OR module is connected to the input terminal of the first non-module. The output terminals of the fifth greater than module and the first non module are connected to the input terminal of the fourth AND module, and the output terminal of the fourth AND module is connected to the input terminal of the X1 criterion satisfying module.

7. The control system for shortening turbine start-up and shutdown time in a single-shaft gas turbine unit according to claim 1, characterized in that, The control system also includes a trip control subsystem, the input of which is connected to the output of the main steam temperature module. The trip control subsystem is used to control the turbine to trip based on the output value and pressure of the main steam temperature module.

8. The control system for shortening turbine start-up and shutdown time in a single-shaft gas turbine unit according to claim 7, characterized in that, The trip control subsystem includes a high-pressure cylinder exhaust temperature module, a high-pressure regulating valve downstream pressure module, a high-pressure bypass valve position module, a mid-pressure bypass valve position module, a fourth control module, and a module that meets the turbine tripping conditions, wherein: The output terminals of the high-pressure cylinder exhaust temperature module, the high-pressure regulating valve downstream pressure module, the high-pressure bypass valve position module, and the middle bypass valve position module are connected to the input terminal of the fourth control module, and the output terminal of the fourth control module is connected to the input terminal of the module that satisfies the turbine tripping conditions.

9. The control system for shortening turbine start-up and shutdown time in a single-shaft gas turbine unit according to claim 8, characterized in that, The fourth control module includes a sixth greater than module, a fourth less than module, a fifth OR module, a first smaller selection module, a seventh greater than module, and a fifth AND module, wherein: The output value of the high-pressure cylinder exhaust temperature module is determined based on the output value of the main steam temperature module, and the output terminal of the high-pressure cylinder exhaust temperature module is connected to the input terminal of the sixth module. The output terminal of the high-pressure module after the high-pressure adjustment valve is connected to the input terminal of the fourth less module; The input terminal of the fifth OR module is connected to the output terminals of the sixth greater than module and the fourth less than module; The input terminal of the first small selection module is connected to the output terminals of the high bypass valve position module and the middle bypass valve position module, and the output terminal of the first small selection module is connected to the input terminal of the seventh greater than module. The input terminal of the fifth AND module is connected to the output terminals of the fifth OR module and the seventh greater than module, and the output terminal of the fifth AND module is connected to the input terminal of the module that satisfies the turbine tripping conditions.

10. A control method for shortening the start-up and shutdown time of a single-shaft gas turbine unit, characterized in that, Includes the following steps: The first control module processes and obtains the output value based on the output values ​​of the high-pressure condensate interlock opening module, the gas turbine ignition module, the turbine tripping module, the high-pressure main steam outlet temperature module, the main steam temperature module, and the main steam valve superheat module. The second control module processes and obtains the output values ​​based on the output values ​​of the high-pressure condensate interlock module, the gas turbine ignition module, the turbine tripped module, the high-pressure outlet electric valve fully open module, the main steam valve front steam superheat module, the high-pressure main steam outlet temperature module, and the main steam temperature module. The automatic opening module of the drain valve outputs according to the output value of the first control module to realize the opening control of the drain valve; The automatic closing module of the drain valve outputs according to the output value of the second control module to realize the closing control of the drain valve.

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