Gas turbine high-pressure bypass start-stop whole process control method

Abstract

The invention discloses a gas turbine high-pressure bypass start-stop whole process control method, which solves the problems of complex gas turbine start-stop control process and low control efficiency, and comprises the following steps: judging the operation state of a unit, and respectively collecting different unit parameters in the start and stop stages of the unit; in the unit operation stage, after a manual shutdown instruction of the gas turbine is received, high-side shutdown control is carried out, and whether high-side shutdown control is completed or not is judged according to whether collected unit parameter signals disappear or not; and in the shutdown state of the unit, whether starting furnace operation characterization exists in the starting stage of the unit or not is judged, if yes, the pressure control mode is directly started, and if not, the valve position control mode is started firstly, and then the pressure control mode is started till the unit operates normally. Pressure changes of the high-pressure steam drum and the medium-pressure steam drum of the waste heat boiler are considered, meanwhile, false liquid level influences are reduced, operation steps are reduced, energy consumption in the unit starting process is reduced, control efficiency and unit economy are improved, and operation is easy.

Description

Technical Field

[0001] This invention relates to the field of thermal automatic control technology for gas-steam combined cycle units, and in particular to a method for controlling the entire process of high-pressure bypass start-up and shutdown of a gas turbine. Background Technology

[0002] Gas-fired combined cycle (Gas-Steam) generators, as an advanced power generation technology, are gaining increasing importance in the power production industry. With the adjustment of the energy structure and the improvement of clean coal utilization technologies, the advantages of Gas-Steam Combined Cycle generators—such as high efficiency and low consumption, rapid start-up, flexible regulation, high availability, low investment, short construction period, and low environmental pollution—are becoming more prominent. However, the dramatic increase in newly installed coal-fired power capacity, the continuous transmission of high-voltage direct current (HVDC), the full absorption of new energy sources such as wind, solar, and hydropower, the significant increase in the scale of centralized HVDC feed-in, and the volatility and uncertainty of new energy sources, are placing higher demands on the peak-shaving capacity and flexibility of traditional generator units in the receiving-end power grid. The need for start-up and shutdown, such as "daytime start-up and nighttime shutdown" and "temporary peak load," will become more urgent.

[0003] For example, the invention disclosed in CN120331977A, a gas turbine start-stop system, a gas-steam combined cycle system, and a gas turbine, includes: a main control module and several execution modules; the main control module, upon receiving a start-stop command, determines the current execution module to be controlled according to a preset start-stop sequence, generates an execution signal corresponding to the current execution module to be controlled, and transmits the execution signal to the current execution module to be controlled; the current execution module to be controlled, upon receiving the execution signal, executes the operation corresponding to the execution signal, and transmits a feedback signal to the main control module upon completion of the operation; the main control module is also used to transmit the execution signal to the next execution module to be controlled based on the feedback signal, until all execution modules have completed start-stop. However, this process involves numerous parameters, multiple control processes, complex operation steps, and low control efficiency. Summary of the Invention

[0004] The purpose of this invention is to solve the problems of complex start-up and shutdown control processes and low control efficiency in the existing gas turbine technology. It provides a gas turbine high-pressure bypass start-up and shutdown control method that takes into account the start-up of the boiler and the pressure changes of the high and medium pressure steam drums of the waste heat boiler, while reducing the influence of false liquid levels, reducing operation steps, reducing energy consumption during unit start-up, improving control efficiency and unit economy, and simplifying operation.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A method for controlling the entire start-up and shutdown process of a gas turbine high-pressure bypass includes the following steps: S1: Determine the unit's operating status and collect different unit parameters during the unit's startup and shutdown phases; S2: During the unit operation phase, when a manual shutdown command for the gas turbine is received, high-pressure bypass shutdown control is performed. The high-pressure bypass shutdown control is determined based on whether the collected unit parameter signals disappear. S3: When the unit is out of service, determine whether there are signs of boiler operation during the unit startup phase. If so, directly enter the pressure control mode; otherwise, first enter the valve position control mode, then enter the pressure control mode, until the unit is running normally.

[0006] The gas turbine high-pressure bypass start-up and shutdown control method provided by this invention ensures that the pressure changes of the high-pressure steam drum and intermediate-pressure steam drum are small throughout the entire gas turbine start-up process, the opening of the high-pressure bypass regulating valve is smooth, and the high-pressure bypass control mode switching is disturbance-free and abrupt, thereby reducing the impact of false liquid levels.

[0007] As a preferred method, when performing valve position control, the valve position control opening is corrected using the auxiliary steam header pressure: a reference value for valve position control opening is set, and the corresponding real-time correction coefficient is obtained from the preset valve position correction coefficient table based on the collected auxiliary steam header pressure value. The corrected valve position control opening is the product of the reference value and the real-time correction coefficient.

[0008] Preferably, when performing valve position control, the larger of the valve position control mode output value and the pressure controller output value is used as the final output command of the high-pressure bypass regulating valve.

[0009] Preferably, when performing valve position control, if the output value of the high-pressure bypass pressure controller is greater than the valve position control opening reference value and the gas turbine speed is greater than the preset speed, then the pressure control mode is entered.

[0010] As a preferred method, historical auxiliary steam header pressure data and the corresponding high-pressure bypass valve opening are collected. Based on the second Lagrange interpolation, the auxiliary steam header pressure-high-pressure bypass valve opening change curve is obtained, and the high-pressure bypass valve flow characteristic curve is obtained. Through data fitting, the correspondence between auxiliary steam header pressure and correction coefficient is obtained.

[0011] Preferably, when the unit is in operation, if a manual shutdown command for the gas turbine is received and the gas turbine flame detector signal disappears, a fast-closing command for the high-pressure bypass control valve is triggered, and the high-pressure bypass control valve closes quickly.

[0012] Preferably, the valve position control opening reference value is 8%, and the preset speed is 2000 rpm.

[0013] As a preferred option, if the high-pressure bypass control valve fast-closing command is less than zero percent, after a delay of t seconds, the high-pressure bypass control valve fast-closing command is restored to complete the high-pressure bypass shutdown control.

[0014] As a preferred method, during the unit shutdown phase, the high-pressure and low-pressure steam drum pressures of the waste heat boiler, the start-up and shutdown status of the boiler, and the warm-up commands for the shaft seal pipes are collected in real time.

[0015] As a preferred method, during the unit startup phase, the actual unit load, gas turbine manual shutdown command, and gas turbine flame detection signal are collected in real time.

[0016] Therefore, the present invention has the following beneficial effects: 1. Considering the effect of different unit shutdown durations on the pressure rise of the high-pressure steam drum after ignition, the larger value between the "valve position control mode output value" and the "pressure controller output value" is used as the final output command of the high-pressure bypass regulating valve to avoid situations where the high-pressure steam drum pressure rises too quickly or the high-pressure bypass regulating valve opening is too small, resulting in a false liquid level in the high-pressure steam drum.

[0017] 2. The high-pressure bypass control mode process is continuously measurable. The conditions for switching the high-pressure bypass control mode are real-time correction of the auxiliary steam header pressure, output value of the high-pressure bypass pressure controller >8%, and gas turbine speed >2000rpm. This ensures uninterrupted switching of the high-pressure bypass control valve opening and prevents situations where the high-pressure bypass control valve opening is closed and the shaft seal is cut off from steam. Attached Figure Description

[0018] Figure 1 This is a flowchart of the steps in the gas turbine high-pressure bypass start-up and shutdown control method of the present invention.

[0019] Figure 2 This is a flowchart of the steps for acquiring unit load data in Example 3. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: Example 1: This embodiment provides a method for controlling the entire process of high-pressure bypass start-up and shutdown of a gas turbine, such as... Figure 1 As shown, the operation process is as follows: Step 1, determine the unit's operating status and collect different unit parameters during the unit startup and shutdown phases; Step 2, during the unit operation phase, perform high-pressure bypass shutdown control and determine whether the high-pressure bypass shutdown control is completed based on whether the collected unit parameter signals disappear; Step 3, during the unit shutdown phase, determine whether there are any signs of boiler operation during the unit startup phase. If so, directly enter the pressure control mode; otherwise, first enter the valve position control mode, then enter the pressure control mode, until the unit is operating normally.

[0021] In the initial startup phase of a gas-steam combined cycle unit with short shutdown intervals, steam is supplied to the unit's shaft seals using the high- and medium-pressure steam parameters of the waste heat boiler to reduce energy consumption. To prevent cold air from entering the gas / steam turbine and avoid issues such as working fluid loss, lubricant deterioration, and vacuum disruption, this process involves numerous parameters and complex operating procedures, making it a key focus for operators and a hot topic in automatic control research.

[0022] The gas turbine high-pressure bypass start-up and shutdown control method provided in this embodiment is an autonomous control method that takes into account both start-up with and without a starter boiler. It requires fewer operation steps for operators. Under the condition of starting the unit without a starter boiler, which increases the unit's energy consumption, it solves the problems of no auxiliary steam and no steam source for the turbine shaft seal. At the same time, it takes into account the real-time status of shutdown duration, high-pressure steam drum pressure, and auxiliary steam header pressure. While ensuring the shaft seal steam supply pressure, it reduces interference with the intermediate-pressure steam drum pressure and the impact of false liquid levels in the intermediate-pressure steam drum. The switching between high-pressure bypass control modes is seamless, saving high-pressure steam drum energy storage and improving the unit's economy.

[0023] The following examples and specific application scenarios further illustrate the technical solution and effects of the present invention. The following examples are explanations of the present invention, but the present invention is not limited to the following examples.

[0024] like Figure 1 As shown, the specific control method for the entire process of starting and stopping the high-pressure bypass of a gas turbine includes the following steps: Step (1): Determine the unit's operating status and collect different unit parameters during the unit's startup and shutdown phases.

[0025] First, determine the unit's operating status, and collect different unit parameters during the unit startup and shutdown phases.

[0026] Specifically, during the unit startup phase, the actual unit load, gas turbine manual shutdown command, and gas turbine flame detector signal are collected in real time.

[0027] During unit shutdown, real-time data are collected on the pressure of the high-pressure steam drum of the waste heat boiler, the pressure of the medium-pressure steam drum of the waste heat boiler, the manual / automatic status of the high-pressure bypass control valve, the speed of the gas turbine, the gas turbine flame detection signal, the start-up and shutdown status of the starter boiler, and the warm-up command for the shaft seal pipeline.

[0028] Based on the determined operating status of the unit, the corresponding control loop is automatically activated.

[0029] Step (2): During the unit operation phase, high-voltage bypass shutdown control is performed. The high-voltage bypass shutdown control is determined based on whether the collected unit parameter signals disappear.

[0030] When the unit is in operation, the high-pressure bypass shutdown control function is activated upon receiving a manual shutdown command from the gas turbine. The high-pressure bypass system is used to directly draw steam from the boiler to the condenser during gas turbine startup, thus preventing excessive thermal shock to the high-pressure cylinder. Furthermore, in the event of load shedding or emergency shutdown, the high-pressure bypass can quickly open to protect the reheater from dry burning and ensure the boiler maintains stable operation at a lower load.

[0031] In this embodiment, when the unit is in operation, after receiving a manual shutdown command from the gas turbine, the high-pressure bypass shutdown control function is activated. The high-pressure bypass will adjust its opening in real time according to the pressure setting curve to track and coordinate with the shutdown process of the gas turbine. After the gas turbine flame detector signal disappears, the high-pressure bypass regulating valve will immediately close quickly, and the high-pressure bypass shutdown control function is completed.

[0032] Step (3): When the unit is out of service, determine whether there are signs of boiler operation during the unit startup phase. If so, directly enter the pressure control mode; otherwise, first enter the valve position control mode, then enter the pressure control mode, until the unit is running normally.

[0033] If the unit is in a shutdown state, the high-pressure bypass start-up control function is activated. Specifically: when the unit is in a shutdown state, it is determined whether there are any signs of boiler operation during the unit startup phase. If the unit has a boiler operating, the high-pressure bypass start-up control enters the pressure control mode; if the unit does not have a boiler operating, the high-pressure bypass start-up control first enters the valve position control mode, and then enters the pressure control mode.

[0034] When performing valve position control, the valve position control opening is corrected using the auxiliary steam header pressure: a reference value for valve position control opening is set, and the corresponding real-time correction coefficient is obtained from the preset valve position correction coefficient table based on the collected auxiliary steam header pressure value. The corrected valve position control opening is the product of the reference value and the real-time correction coefficient.

[0035] When performing valve position control, if the output value of the high-pressure bypass pressure controller is greater than the valve position control opening reference value and the gas turbine speed is greater than the preset speed, then the pressure control mode is entered.

[0036] When determining whether there are signs of boiler operation during the unit startup phase, the operator can manually select the signal that indicates the operation.

[0037] The gas turbine high-pressure bypass start-up and shutdown whole-process control method and gas turbine high-pressure bypass start-up and shutdown whole-process control system provided in this embodiment have the following beneficial effects: (1) The logic changes on the TCS side of the gas turbine are small and the implementation is highly feasible. This technology can be implemented in gas turbine units that are involved in starting without a starter furnace.

[0038] (2) The disappearance of the gas turbine manual stop command and the gas turbine fire detector signal serves as the triggering characteristic of the fast closing of the high-pressure bypass control valve, adapting to various shutdown conditions of the gas turbine and preparing for subsequent start-up without a starter furnace.

[0039] (3) Considering the effect of different shutdown durations on the pressure rise of the high-pressure steam drum after ignition, the larger value between the "valve position control mode output value" and the "pressure controller output value" is used as the final output command of the high-pressure bypass regulating valve to avoid the situation where the pressure rise of the high-pressure steam drum is too fast and the opening of the high-pressure bypass regulating valve is too small, resulting in a false liquid level in the high-pressure steam drum.

[0040] (4) The high-pressure bypass control mode process is continuously measurable. By setting the auxiliary steam main pipe pressure real-time correction, the high-pressure bypass pressure controller output threshold and the gas turbine speed threshold as the conditions for switching the high-pressure bypass control mode, the high-pressure bypass valve opening is switched without disturbance, and the situation of the high-pressure bypass valve opening being closed and the shaft seal being cut off is eliminated.

[0041] Example 2: This embodiment, based on Embodiment 1, provides a method for controlling the entire process of high-pressure bypass start-up and shutdown of a gas turbine. When the high-pressure bypass start-up control enters the "valve position control mode," the valve position control opening is corrected to improve control accuracy. The high-pressure bypass shutdown control function and the high-pressure bypass start-up control function are further explained.

[0042] Specifically, this embodiment provides a method for controlling the entire process of high-pressure bypass start-up and shutdown of a gas turbine, including: (1) When the unit is in operation, after receiving the manual shutdown command of the gas turbine, the high-voltage bypass shutdown control function is activated.

[0043] When the high-pressure bypass shutdown control function receives the gas turbine manual shutdown command and the gas turbine ignition detector signal disappears, it triggers the high-pressure bypass regulating valve fast-closing command, and the high-pressure bypass regulating valve immediately closes. When the high-pressure bypass regulating valve command is <0%, after a 5-second delay, the high-pressure bypass regulating valve fast-closing command is restored, and the high-pressure bypass shutdown control function is completed.

[0044] The high-pressure bypass shutdown control function controls the high-pressure bypass valve. The high-pressure bypass adjusts its opening in real time according to the pressure setting curve to track and coordinate with the gas turbine shutdown process.

[0045] (2) When the unit is out of service, activate the high-voltage bypass start control function.

[0046] When the boiler is running, when the high-pressure bypass start-up control function receives the shaft seal pipe warm-up command, the high-pressure bypass start-up control enters the pressure control mode until the unit is running normally.

[0047] The pressure control mode controls the main steam pressure by controlling the high-pressure bypass valve.

[0048] When the boiler is started up and shut down, if the high-pressure bypass start-up control function receives a shaft seal pipeline warm-up command, it enters valve position control mode. The valve position control opening is based on 8% and is corrected in real-time by the auxiliary steam header pressure. In this mode, the larger of the valve position control mode output value and the pressure controller output value is used as the final output command for the high-pressure bypass regulating valve. This avoids situations where the high-pressure steam drum pressure rises too quickly or the high-pressure bypass regulating valve opening is too small, leading to false high-pressure steam drum liquid levels.

[0049] When the output value of the high-pressure bypass pressure controller exceeds 8% and the gas turbine speed exceeds 2000 rpm, the high-pressure bypass start control enters pressure control mode until the unit is running normally. Real-time correction of the auxiliary steam header pressure and the conditions of the high-pressure bypass control mode switching being greater than 8% and the gas turbine speed exceeding 2000 rpm, ensure uninterrupted switching of the high-pressure bypass control valve opening and prevent situations where the high-pressure bypass control valve closes and the shaft seal is cut off from steam.

[0050] Specifically, when the high-pressure bypass start-up control enters the valve position control mode, the reference value of the valve position control opening is corrected in real time by the auxiliary steam header pressure. The real-time correction coefficient is shown in Table 1. Table 1: Real-time Correction Table of High-Pressure Bypass Opening Coefficient for Auxiliary Steam Headpipe Pressure Auxiliary steam header pressure (MPa) Correction coefficient 5 1 0.75 1 0.65 1.5 0.55 2 0.45 2.5 0.35 3 -5 3 It can be seen that the correction factor corresponding to the auxiliary steam header pressure fluctuates significantly when the auxiliary steam header pressure is between 0 and 1 MPa. The corrected valve position control opening value is the product of the reference value of the valve position control opening and the real-time correction factor. For example, if the reference value of the valve position control opening is 8%, and the auxiliary steam header pressure is 0.65 MPa, then the corresponding correction factor is 1.5. Therefore, the corrected valve position control opening value is the product of the reference value of 8% and the correction factor of 1.5.

[0051] The correction coefficients were derived by fitting historical curves, big data, and the flow characteristic curve of the high-pressure bypass control valve. Specifically, under different auxiliary steam header pressures, in order to prevent the turbine shaft seal pressure from becoming too low or even zero, the opening of the high-pressure bypass control valve needs to be adjusted in real time. For example, when the auxiliary steam header pressure is high, the high-pressure bypass valve can be opened smaller, and a smaller opening can still meet the turbine shaft seal pressure requirements, and it is also more energy-efficient; when the auxiliary steam header pressure is low, the high-pressure bypass valve needs to be opened larger, and only a larger opening can meet the turbine shaft seal pressure requirements.

[0052] Specifically, this includes: collecting historical auxiliary steam header pressure data and the corresponding high-pressure bypass valve opening; fitting the auxiliary steam header pressure-high-pressure bypass valve opening change curve based on second-order Lagrange interpolation; obtaining the high-pressure bypass valve flow characteristic curve; and obtaining the correspondence between auxiliary steam header pressure and correction coefficient through data fitting.

[0053] This embodiment provides a full-process control method for the start-up and shutdown of a gas turbine high-pressure bypass, which can greatly reduce the operation steps for operators. Under the condition of starting the unit without a starter furnace, which increases the energy consumption of the unit, it solves the problems of no auxiliary steam and no steam source for the turbine shaft seal. At the same time, it takes into account the real-time status of shutdown time, high-pressure steam drum pressure, and auxiliary steam header pressure. While ensuring the shaft seal steam supply pressure, it reduces the interference to the intermediate-pressure steam drum pressure and the impact of false liquid levels in the intermediate-pressure steam drum. The switching between high-pressure bypass control modes is seamless, saving high-pressure steam drum energy storage and improving the unit's economy.

[0054] Example 3: Based on Example 1, this embodiment adds a detailed process for collecting unit data, providing a method for controlling the entire process of high-pressure bypass start-up and shutdown of a gas turbine.

[0055] A method for controlling the entire process of high-pressure bypass start-up and shutdown of a gas turbine includes the following steps: during the unit start-up phase, real-time acquisition of the actual unit load, gas turbine manual stop command, and gas turbine flame detection signal; during the unit shutdown phase, real-time acquisition of the high-pressure steam drum pressure of the waste heat boiler, the medium-pressure steam drum pressure of the waste heat boiler, the manual / automatic status of the high-pressure bypass regulating valve, the gas turbine speed, the gas turbine flame detection signal, the start-up and shutdown status of the starter boiler, and the shaft seal pipeline warm-up command.

[0056] In this embodiment, as Figure 2 As shown, the data acquisition process includes: setting the basic format of the command frame for the host computer and the basic format of the response frame for the acquisition terminal. The response frame includes time information and the data acquired at that time. The host computer first sends an acquisition signal to the acquisition terminal according to the data format agreed upon in the communication protocol. After receiving the acquisition signal, the acquisition terminal sends a response message to the host computer, establishing a communication connection between the host computer and the acquisition terminal. The host computer sends a data acquisition command to the acquisition terminal at fixed intervals. After receiving the data acquisition command, the acquisition terminal sends the acquired real-time data to the host computer.

[0057] Different signals require different acquisition terminals. For example, a tachometer is used to acquire the speed of a gas turbine.

[0058] This embodiment also includes verifying the real-time data frames sent by the acquisition terminal. Specifically, it involves: first, determining whether the preamble, frame header, address, and command of the real-time data frame conform to the communication protocol. If they conform, proceed to the second step of verification; otherwise, delete the data frame. The second step involves determining whether the number of bytes in the real-time data frame conforms to the communication protocol. If it conforms, proceed to the next step of verification; otherwise, delete the data frame.

[0059] Extract the fields representing gas turbine parameters from the real-time data frame, parse the bytes representing time information in these fields, parse the bytes representing real-time operating parameters of the gas turbine in these fields, and display the parsing results.

[0060] To ensure the accuracy and security of data acquisition, and to provide precise data support for subsequent control modes.

[0061] Example 4: This embodiment provides a gas turbine high-pressure bypass start-stop full-process control system to implement the gas turbine high-pressure bypass start-stop full-process control methods in Embodiments 1 to 3.

[0062] Specifically, a gas turbine high-pressure bypass start-stop full-process control system includes: The gas turbine operating status determination module is used to determine whether the gas turbine unit is in an operating or shut-down state, and sends the unit operating signal or unit shutdown signal to the controller, and sends the data acquisition signal to the gas turbine data acquisition module. Specifically, if the gas turbine unit is in a shut-down state, it sends a first parameter acquisition signal to the gas turbine data acquisition module; if the gas turbine unit is in an operating state, it sends a second parameter acquisition signal to the gas turbine data acquisition module.

[0063] The first parameter includes the actual load data of the unit, the manual shutdown command of the gas turbine, and the gas turbine flame detection signal; the second parameter includes the high-pressure steam drum pressure of the waste heat boiler, the medium-pressure steam drum pressure of the waste heat boiler, the manual / automatic status of the high-pressure bypass control valve, the gas turbine speed, the gas turbine flame detection signal, the start-up and shutdown status of the starter boiler, and the shaft seal pipeline warm-up command.

[0064] The gas turbine data acquisition module receives signals from the gas turbine operating status judgment module. If it receives a first parameter acquisition signal, it acquires the first parameter; if it receives a second parameter acquisition signal, it acquires the second parameter and sends the acquired data to the controller.

[0065] The controller, based on the gas turbine unit operating status signal sent by the gas turbine operating status judgment module and the data from the fuel turbine data acquisition module, controls the gas turbine equipment to perform corresponding actions.

[0066] Specifically: If the controller receives a gas turbine unit shutdown status signal, it controls the high-pressure bypass system to stop operating. At this time, the gas turbine data acquisition module continues to acquire the first parameter. If the gas turbine data acquisition module fails to acquire the gas turbine manual stop command and the gas turbine flame detector signal, it sends an acquisition failure signal to the controller. The controller then controls the high-pressure bypass regulating valve to close quickly, and the high-pressure bypass shutdown function is completed.

[0067] The high-pressure bypass system is primarily used to regulate the inlet steam pressure of the gas turbine's high-pressure cylinder to a set value and maintain the outlet temperature by controlling the spray valve to prevent overheating of the reheater inlet. In the event of load shedding or emergency shutdown, the high-pressure bypass control system can quickly open the bypass valve and spray valve. During unit startup or shutdown, the high-pressure bypass system controls the steam pressure in the high-pressure pipeline to ensure operational stability. In case of emergency shutdown, the high-pressure bypass valve and spray valve open rapidly to release excess steam and improve unit safety. It includes a high-pressure bypass valve, a spray regulating valve, and a spray isolation valve. The high-pressure bypass valve functions as a startup regulating valve, a pressure-reducing bypass valve, and a safety valve, and can replace the boiler safety valve and adapt to the unit's sliding parameter start-up and shutdown requirements.

[0068] If the controller receives a gas turbine unit operating status signal, it activates the high-pressure bypass system. During this time, the gas turbine data acquisition module continuously collects the second parameter, and the control valve extracts the start-up boiler start / stop status parameter from this parameter to determine the start-up boiler status. If the start-up boiler is running, the high-pressure bypass system activates and enters pressure control mode. If the start-up boiler is not running, the controller first enters valve position control mode, controlling the valve opening to the standard value. Then, if the gas turbine speed collected by the gas turbine data acquisition module reaches the preset speed threshold and the high-pressure bypass pressure controller output value reaches the preset standard value, it switches to pressure control mode.

[0069] Valve position control refers to controlling the valve opening degree in a high-pressure bypass system.

[0070] The gas turbine high-pressure bypass start-stop full-process control system provided in this embodiment has small pressure changes in the high-pressure steam drum and intermediate-pressure steam drum during the entire start-up process, smooth opening of the high-pressure bypass regulating valve, and no disturbance or sudden change in the high-pressure bypass control mode switching.

[0071] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Other variations and modifications are possible without departing from the technical solutions described in the claims.

Claims

1. A method of controlling a gas turbine high pressure bypass start-stop full process, characterized in that, Comprise: S1: judge the unit operation state, collect different unit parameters in the unit start and stop stage respectively; S2: in the unit operation stage, when receiving the manual stop instruction of gas turbine, carry out high bypass stop control, and judge whether the high bypass stop control is completed according to whether the collected unit parameter signal disappears or not; S3: in the unit stop state, judge whether there is a start-up furnace operation representation in the unit start-up stage, if yes, directly enter the pressure control mode, otherwise, first enter the valve position control mode, and then enter the pressure control mode until the unit operates normally.

2. A method for controlling the whole process of high-pressure bypass start-stop of a gas turbine according to claim 1, characterized in that, When carrying out the valve position control, the valve position control opening degree is corrected by using the auxiliary steam header pressure: set the valve position control opening degree reference value, obtain the corresponding real-time correction coefficient from the preset valve position correction coefficient table according to the collected auxiliary steam header pressure value, and the corrected valve position control opening degree is the product of the reference value and the real-time correction coefficient.

3. A method for controlling the whole process of high-pressure bypass start-stop of a gas turbine according to claim 1 or 2, characterized in that, When carrying out the valve position control, the larger value between the valve position control mode output value and the pressure controller output value is taken as the final output instruction of the high pressure bypass regulating valve.

4. A method of controlling a high pressure bypass start / stop process of a gas turbine according to claim 1 or 2, characterized in that, When carrying out the valve position control, if the high bypass pressure controller output value is greater than the valve position control opening degree reference value and the gas turbine speed is greater than the preset speed, enter the pressure control mode.

5. A method for controlling the entire process of high-pressure bypass start and stop of a gas turbine according to claim 1, characterized by, Collect the historical auxiliary steam header pressure data and the corresponding high bypass valve opening degree, obtain the auxiliary steam header pressure-high bypass valve opening degree change curve by fitting according to the quadratic Lagrange interpolation, obtain the high bypass valve flow characteristic curve, and obtain the corresponding relationship between the auxiliary steam header pressure and the correction coefficient through data fitting.

6. A control method for high pressure bypass start / stop of a gas turbine according to claim 1 or 2 or 5, characterized in that, When the unit is in operation state, if the manual stop instruction of the gas turbine is received and the gas turbine fire detection signal disappears, the high pressure bypass valve fast closing instruction is triggered, and the high pressure bypass valve is fast closed.

7. A method for controlling the entire process of high-pressure bypass start and stop of a gas turbine according to claim 2, characterized by, The valve position control opening degree reference value is 8%, and the preset speed is 2000 rpm.

8. A method of controlling a high pressure bypass start / stop process of a gas turbine according to claim 1 or 2 or 5 or 7, characterized in that, If the high pressure bypass valve fast closing instruction is less than zero, after a delay of t seconds, the high pressure bypass valve fast closing instruction is restored, and the high bypass stop control is completed.

9. A method for controlling the whole process of high-pressure bypass start / stop of a gas turbine according to claim 1 or 2 or 5 or 7, characterized in that, In the unit stop stage, the high pressure drum pressure and the low pressure drum pressure of the waste heat boiler, the start-up furnace start-stop state and the shaft seal pipe warm-up instruction are collected in real time.

10. A method of controlling a high pressure bypass start / stop process of a gas turbine according to claim 1 or 2 or 5 or 7, characterized in that, In the unit start-up stage, the actual load of the unit, the manual stop instruction of the gas turbine and the gas turbine fire detection signal are collected in real time.

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