A high-pressure feed water regulating valve control system and device for gas turbine unit start-stop stage

Abstract

The application discloses a high-pressure feedwater regulating valve control system for gas unit start-stop stage, comprising a parameter acquisition module, a logic judgment module, a switching execution module, an instruction output module, a rate setting module and a driving module, wherein the parameter acquisition module is used for parameter acquisition, the logic judgment module is used for generating a switching control signal according to the parameters collected by the parameter acquisition module, the switching execution module, the instruction output module and the rate setting module are used for generating a second control instruction according to the switching control signal, and the driving module is used for driving the main regulating valve and the bypass regulating valve according to the second control instruction, so that the technical problems of single valve failure and large disturbance in manual switching in the prior art are solved; and the rate setting module and the instruction output module are used for adaptive adjustment of the action rate of the regulating valve, so that the stability and emergency responsiveness are considered, and the operation reliability, the control stability and the automation level of the feedwater regulating system are greatly improved.

Description

Technical Field

[0001] This invention relates to the field of intelligent control technology for gas turbine units, and in particular to a high-pressure feedwater regulating valve control system and device for the start-up and shutdown phases of a gas turbine unit. Background Technology

[0002] In a gas turbine unit with a combined cycle of gas and steam, the high-pressure feedwater regulating valve of the gas turbine unit feedwater system is the core regulating equipment for controlling the water level in the steam drum, maintaining stable steam parameters, and ensuring the safe and economical operation of the unit. It is also a key link in ensuring the safe, continuous, and economical operation of the gas turbine unit.

[0003] Currently, the feedwater system of gas turbine units adopts a single-valve control mode with a single regulating valve or a manual redundancy switching mode with a main regulating valve and a bypass regulating valve. However, high-pressure feedwater regulating valves operate under conditions of high temperature, high pressure, and large differential pressure fluctuations for extended periods, making them prone to faults such as valve position jamming, loss of air / power in the drive module, large deviations between commands and feedback, and distortion of flow characteristics. These faults severely impact the stability of the power grid and the availability of the gas turbine units.

[0004] There is an urgent need for a high-pressure feedwater regulating valve control system that can automatically switch regulating valves to comprehensively improve the operational reliability of gas turbine units. Summary of the Invention

[0005] This invention provides a high-pressure feedwater regulating valve control system for the start-up and shutdown phases of a gas turbine unit. By using parameters acquired by a parameter acquisition module, the system controls the automatic switching between the main regulating valve and the bypass regulating valve, achieving automatic and seamless switching of the regulating valve and adaptive adjustment of the regulating valve's operating rate, thereby comprehensively improving the reliability, stability, and automation level of the gas turbine unit.

[0006] According to one aspect of the present invention, a high-pressure feedwater regulating valve control system for the start-up and shutdown phases of a gas turbine unit is provided, comprising: a parameter acquisition module, a logic determination module, a switching execution module, an instruction output module, and a rate setting module. and drive Dynamic module ; The parameter acquisition module is used to acquire real-time operating parameters of the gas turbine unit and status parameters of the regulating valves, including a main regulating valve and a bypass regulating valve. The input terminal of the logic determination module is connected to the output terminal of the parameter acquisition module, and is used to determine whether to switch the control valve based on the control valve status parameters and preset control valve switching conditions, so as to obtain a switching control signal. The input terminal of the switching execution module is connected to the output terminal of the logic determination module, and is used to generate a first control command based on the switching control signal; The input terminal of the rate setting module is connected to the output terminal of the parameter acquisition module, and is used to generate the opening change rate based on the operating parameters of the gas turbine unit; The first input terminal of the instruction output module is connected to the output terminal of the switching execution module, the second input terminal is connected to the output terminal of the rate setting module, and the output terminal of the instruction output module is connected to the regulating valve. It is used to generate a second control instruction based on the first control instruction and the opening change rate, and output the second control instruction to the drive module. The drive module is connected to the main regulating valve and the bypass regulating valve, and the drive module is used to... The second control command drives the main regulating valve and the bypass regulating valve. .

[0007] Optionally, the operating parameters of the gas turbine unit include: the high-pressure steam drum liquid level setpoint, the current liquid level of the high-pressure steam drum, and the switching status of the bypass regulating valve; The regulating valve status parameters include: bypass regulating valve opening command, bypass regulating valve automatic status, bypass regulating valve current opening, and main regulating valve automatic status; The main regulating valve includes a 100% capacity regulating valve; the bypass regulating valve includes a 30% capacity regulating valve.

[0008] Optionally, the switching conditions for the regulating valve include the conditions for switching the main regulating valve to the bypass regulating valve and the conditions for switching the bypass regulating valve to the main regulating valve. The conditions for switching the main control valve to the bypass control valve include: the main control valve is in automatic mode, the bypass control valve is in automatic mode, and the current opening degree of the bypass control valve is greater than a first threshold. The conditions for the bypass regulating valve to switch to the main regulating valve include: the main regulating valve is in automatic mode, the bypass regulating valve is in automatic mode, and the current opening degree of the bypass regulating valve is less than the second threshold.

[0009] Optionally, the first threshold is greater than the second threshold.

[0010] Optionally, the logic determination module includes a first comparison unit, a second comparison unit, and an AND unit; The first comparison unit is a greater than comparison unit, and the second comparison unit is a less than comparison unit; The switching control signal includes a first trigger signal and a second trigger signal. When the first trigger signal is high, it triggers the bypass regulating valve to switch the main regulating valve. When the second trigger signal is high, it triggers the main regulating valve to switch the bypass regulating valve. The first comparison unit is used to compare the current opening of the bypass regulating valve with the first threshold; the AND unit is used to perform an AND operation on the automatic state of the main regulating valve, the automatic state of the bypass regulating valve, and the comparison result of the first comparison unit, and output a first trigger signal. The second comparison unit is used to compare the current opening degree of the bypass regulating valve with the second threshold and output a second trigger signal.

[0011] Optionally, the switching execution module includes a pulse unit, an SR trigger, a third switching unit, and a fourth constant; The fourth constant is the fixed opening degree of the main control valve; The input terminal of the pulse unit is connected to the output terminal of the AND unit, the set terminal of the SR flip-flop is connected to the output terminal of the pulse unit, the reset terminal of the SR flip-flop is connected to the output terminal of the second comparison unit, the output terminal of the SR flip-flop is connected to the enable terminal of the third switching unit, the first input terminal of the third switching unit receives the opening command of the bypass regulating valve, and the second input terminal of the third switching unit is connected to the fourth constant. The third switching unit selects either the bypass regulating valve opening command or the fourth constant as the first control command based on the output of the SR trigger.

[0012] Optionally, the rate setting module includes a first constant, a second constant, and a subtraction unit, a third comparison unit, a delay unit, and a first switching unit connected in sequence; The subtraction unit is used to calculate the difference between the high-pressure steam drum liquid level set value and the current liquid level of the high-pressure steam drum, and the third comparison unit is used to determine whether the difference is within a preset range; The first input terminal of the first switching unit is connected to the first constant, the second input terminal of the first switching unit is connected to the second constant, and the enable terminal of the first switching unit is connected to the output terminal of the third comparison unit. The first switching unit selects a first constant or a second constant as the opening change rate based on the output of the third comparison unit; The second constant is greater than the first constant.

[0013] Optionally, the rate setting module further includes a non-interchange unit, a second switching unit, and a third constant; The non-unit is used to invert the switching state of the bypass regulating valve, and the output terminal of the non-unit is connected to the enable terminal of the second switching unit. The first input terminal of the second switching unit is connected to the output terminal of the first switching unit, and the second input terminal of the second switching unit is connected to the third constant. The second switching unit selects either the output of the first switching unit or the third constant as the opening change rate based on the output of the non-unit.

[0014] Optionally, the instruction output module includes a rate limiting unit; the instruction input terminal of the rate limiting unit is connected to the output terminal of the switching execution module, the rate limit input terminal of the rate limiting unit is connected to the output terminal of the rate setting module, and the output terminal of the rate limiting unit is connected to the drive module.

[0015] According to a second aspect of the present invention, a high-pressure feedwater regulating valve control device for the start-up and shutdown phase of a gas turbine unit is provided, comprising the high-pressure feedwater regulating valve control system for the start-up and shutdown phase of a gas turbine unit as described above.

[0016] The high-pressure feedwater regulating valve control system for the start-up and shutdown phase of a gas turbine unit, as provided in this invention, includes a parameter acquisition module, a logic determination module, a switching execution module, an instruction output module, a rate setting module, and a drive module. First, the parameter acquisition module acquires parameters. Then, the logic determination module generates a switching control signal based on the acquired parameters. Next, the switching execution module, instruction output module, and rate setting module work together to generate a second control instruction based on the switching control signal. Finally, the drive module drives the main regulating valve and the bypass regulating valve according to the second control instruction. This solves the technical problems of easy loss of control due to single valve failure and large disturbances during manual switching in existing technologies. Furthermore, through the cooperation of the rate setting module and the instruction output module, adaptive adjustment of the regulating valve's operating rate is achieved, balancing stability and emergency response, significantly improving the operational reliability, control stability, and automation level of the feedwater regulating system. It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of a high-pressure feedwater regulating valve control system for the start-up and shutdown phase of a gas turbine unit, provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of another high-pressure feedwater regulating valve control system for the start-up and shutdown phase of a gas turbine unit provided in an embodiment of the present invention. Detailed Implementation

[0019] 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.

[0020] 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 data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, any variations of the terms "comprising" and "having" 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.

[0021] To address the aforementioned technical problems, the embodiments of the present invention provide the following technical solutions: Figure 1 This is a schematic diagram of a high-pressure feedwater regulating valve control system for the start-up and shutdown phases of a gas turbine unit, provided in an embodiment of the present invention. (Refer to...) Figure 1This invention provides a high-pressure feedwater regulating valve control system for the start-up and shutdown phases of a gas turbine unit, comprising a parameter acquisition module 1, a logic determination module 2, a switching execution module 3, an instruction output module 4, a rate setting module 5, and a drive module 6. The parameter acquisition module 1 is used to acquire real-time operating parameters of the gas turbine unit and regulating valve status parameters. The regulating valve includes a main regulating valve and a bypass regulating valve. The input terminal of the logic determination module 2 is connected to the output terminal of the parameter acquisition module 1, and is used to determine whether to switch the regulating valve based on the regulating valve status parameters and preset regulating valve switching conditions, thereby obtaining a switching control signal. The input terminal of the switching execution module 3 is connected to the output terminal of the logic determination module 2, and is used to generate a control signal based on the switching control signal. The first control command is generated; the input terminal of the rate setting module 5 is connected to the output terminal of the parameter acquisition module 1, and is used to generate the opening change rate based on the operating parameters of the gas turbine unit; the first input terminal of the command output module 4 is connected to the output terminal of the switching execution module 3, the second input terminal is connected to the output terminal of the rate setting module 5, and the output terminal of the command output module 4 is connected to the regulating valve, and is used to generate a second control command according to the first control command and the opening change rate, and output the second control command to the drive module 6; the drive module 6 is connected to the main regulating valve and the bypass regulating valve, and the drive module 6 is used to drive the main regulating valve and the bypass regulating valve according to the second control command.

[0022] Among them, the opening change rate refers to the maximum allowable change in the opening of the control valve per unit time, which is used to limit the opening speed of the control valve and avoid system disturbances caused by sudden changes in opening; the drive module is an actuator with position feedback and fault diagnosis functions to ensure that the valve status of the main control valve and the bypass control valve can be monitored in real time.

[0023] Specifically, the start-up and shutdown process of a gas turbine unit is a dynamic process characterized by drastic changes in operating conditions and significant fluctuations in key parameters. In this embodiment, the parameter acquisition module 1 collects the operating parameters of the gas turbine unit and the status parameters of the main and bypass regulating valves in real time at a fixed sampling period. After acquisition, the collected data is preprocessed and then transmitted to the logic judgment module 2 and the rate setting module 5, respectively. The logic judgment module 2 receives the preprocessed regulating valve status parameters and continuously compares and verifies them with preset regulating valve switching conditions. When the regulating valve status parameters fully meet the regulating valve switching conditions, a switching control signal is generated and output to the switching execution module 3. The switching execution module 3 then determines the switching control signal based on its type. The system selects the corresponding regulating valve opening command source, generates a first control command, and outputs it to the command output module 4. The rate setting module 5 receives the preprocessed gas turbine unit operating parameters, generates an opening change rate adapted to the current operating conditions of the gas turbine unit based on the current operating conditions of the gas turbine unit, and outputs it to the command output module 4. The command output module 4 receives the first control command and the opening change rate, smooths the first control command according to the opening change rate, generates a second control command, and outputs it to the drive module 6. Finally, the drive module 6 drives the main circuit regulating valve or the bypass regulating valve to complete the corresponding action according to the second control command.

[0024] In this embodiment, parameters are first acquired through parameter acquisition module 1, then logic judgment module 2 generates a switching control signal based on the parameters acquired by parameter acquisition module 1, and then switching execution module 3 generates a first control command adapted to the switching process based on the switching control signal. This solves the core problems of easy loss of control due to single valve failure and large disturbances during manual switching in the prior art. Furthermore, through the cooperation of rate setting module 5 and command output module 4, adaptive adjustment of the regulating valve action rate is achieved, taking into account both regulation stability and emergency response. This significantly improves the operational reliability, control stability and automation level of the control system.

[0025] In one possible implementation, the operating parameters of the gas turbine unit include: the high-pressure steam drum liquid level setpoint, the current liquid level of the high-pressure steam drum, and the switching status of the bypass regulating valve; the regulating valve status parameters include: the bypass regulating valve opening command, the automatic status of the bypass regulating valve, the current opening of the bypass regulating valve, and the automatic status of the main regulating valve; the main regulating valve includes a 100% capacity regulating valve; and the bypass regulating valve includes a 30% capacity regulating valve.

[0026] Specifically, the high-pressure steam drum water level setpoint refers to the target control value of the boiler high-pressure steam drum water level issued based on the current gas turbine unit load, and is the target benchmark for high-pressure steam drum water level regulation; the bypass regulating valve switching status refers to the switch signal of the bypass regulating valve switching operation manually triggered by the operator, which has a higher priority than the automatic switching logic of the control system in this embodiment, and is a way to leave room for manual intervention; the bypass regulating valve opening command refers to the dynamic adjustment command for adjusting the opening of the bypass regulating valve under normal operating conditions, such as under normal operating conditions where there is no need to switch the regulating valve, the proportional-integral-derivative (PID) function... When the Derivative (PID) control module needs to adjust the opening of the bypass control valve, it issues a bypass control valve opening command. The automatic status of the bypass control valve and the automatic status of the main control valve refer to the on / off signals reflecting the corresponding control modes of the control valves. A signal of 1 indicates that the valve is in automatic control mode and can receive automatic control commands from the control system; a signal of 0 indicates that the valve is in manual mode and does not receive automatic control commands from the control system. The current opening of the bypass control valve refers to the actual opening value of the valve fed back by the drive module 6, reflecting the true working position of the valve. The 100% capacity control valve refers to the main control valve whose rated flow capacity can cover 100% of the feedwater flow demand of the gas turbine unit under rated operating conditions, and is suitable for the large flow regulation demand of the unit under high load conditions. The 30% capacity control valve refers to the bypass control valve whose rated flow capacity can cover 30% of the feedwater flow demand of the gas turbine unit under rated operating conditions, and is suitable for the small flow high-precision regulation demand of the unit during start-up and shutdown and low load conditions, and can also be used as an emergency backup for the main control valve.

[0027] In this embodiment, parameter acquisition module 1 acquires analog signals of the high-pressure steam drum liquid level setpoint, current high-pressure steam drum liquid level, bypass control valve opening command, and current bypass control valve opening through the analog acquisition channel. It also acquires switch signals of the bypass control valve switching status, bypass control valve automatic status, and main control valve automatic status through the digital acquisition channel. After acquisition, the analog signals are filtered and range-converted, and the digital signals are de-jittered and opto-isolated. Standardized parameters are then output to subsequent logic modules. This solves the problem of poor regulation quality across the entire load range in existing single-valve solutions and achieves high-precision regulation over a wide load range for the unit.

[0028] In one possible implementation, the switching conditions for the regulating valve include conditions for switching the main regulating valve to the bypass regulating valve and conditions for switching the bypass regulating valve to the main regulating valve; wherein, the conditions for switching the main regulating valve to the bypass regulating valve include: the main regulating valve being in automatic mode, the bypass regulating valve being in automatic mode, and the current opening degree of the bypass regulating valve being greater than a first threshold; the conditions for switching the bypass regulating valve to the main regulating valve include: the main regulating valve being in automatic mode, the bypass regulating valve being in automatic mode, and the current opening degree of the bypass regulating valve being less than a second threshold.

[0029] Specifically, the first threshold refers to the upper limit of the maximum effective adjustment opening of the bypass control valve, which is preset. If the first threshold is exceeded, the adjustment accuracy and flow characteristics of the bypass control valve will drop significantly. The first threshold can be 25%. The second threshold refers to the lower limit of the minimum effective adjustment opening of the bypass control valve, which is preset. If the second threshold is lower than the second threshold, the bypass control valve enters the small opening distortion range, and the adjustment stability drops significantly. The second threshold can be 8%.

[0030] Specifically, in this embodiment, the bidirectional switching between the main control valve and the bypass control valve is achieved by setting the switching conditions of the control valve. When the gas unit experiences a load reduction or an abnormal operation of the main control valve, the main control valve switches to the bypass control valve. When the gas unit experiences a load increase or an insufficient regulating capacity of the bypass control valve, the bypass control valve switches to the main control valve.

[0031] To ensure accurate switching of the control valves, logic judgment module 2 simultaneously verifies three sub-conditions: the main control valve is in automatic mode, the bypass control valve is in automatic mode, and the current opening degree of the bypass control valve is greater than a first threshold. Only when all three sub-conditions are met simultaneously is the condition for switching the main control valve to the bypass control valve satisfied, and the corresponding switching control signal is output. Similarly, for the condition for switching the bypass control valve to the main control valve, logic judgment module 2 simultaneously verifies three sub-conditions: the main control valve is in automatic mode, the bypass control valve is in automatic mode, and the current opening degree of the bypass control valve is less than a second threshold. Only when all three sub-conditions are met simultaneously is the condition for switching the bypass control valve to the main control valve satisfied, and the corresponding switching control signal is output. The control valve switching method in this embodiment covers the full-condition switching requirements for unit load increases and decreases, improving the reliability and automation level of the control system.

[0032] In one possible implementation, the first threshold is greater than the second threshold.

[0033] Specifically, this embodiment prevents frequent switching between the main control valve and the bypass control valve by setting a first threshold greater than a second threshold. During the operation of the control system, when the current opening of the bypass control valve continuously increases and exceeds the first threshold, the bypass control valve is triggered to switch to the main control valve, and the control authority is transferred to the main control valve. Conversely, when the current opening of the bypass control valve continuously decreases and falls below the second threshold, the main control valve is triggered to switch to the bypass control valve, and the control authority is transferred to the bypass control valve. The opening range between the first and second thresholds is a switching dead zone; when the current opening of the bypass control valve fluctuates within this range, no switching action is triggered. This completely avoids the problem of repeated switching and oscillation of the control valve caused by frequent fluctuations in the current opening of the bypass control valve near a single critical point, further improving the stability of the gas turbine unit's operation.

[0034] Figure 2This is a schematic diagram of another high-pressure feedwater regulating valve control system for the start-up and shutdown phase of a gas turbine unit provided in an embodiment of the present invention. (Refer to...) Figure 2 The logic determination module 2 includes a first comparison unit 21, a second comparison unit 22, and an AND unit 23; the first comparison unit 21 is a greater than comparison unit, and the second comparison unit 22 is a less than comparison unit; the switching control signal includes a first trigger signal and a second trigger signal, wherein when the first trigger signal is high, it triggers the bypass regulating valve to switch to the main regulating valve, and when the second trigger signal is high, it triggers the main regulating valve to switch to the bypass regulating valve; the first comparison unit 21 is used to compare the current opening degree of the bypass regulating valve with the first threshold; the AND unit 23 is used to perform an AND operation on the automatic state of the main regulating valve, the automatic state of the bypass regulating valve, and the comparison result of the first comparison unit 21, and outputs a first trigger signal; the second comparison unit 22 is used to compare the current opening degree of the bypass regulating valve with the second threshold, and outputs a second trigger signal.

[0035] Specifically, the first comparison unit 21 is a calculation unit that implements the function of comparing the magnitude of analog quantities. When the current opening degree of the bypass regulating valve is greater than the first threshold, it outputs a high-level signal, and otherwise outputs a low-level signal. The second comparison unit 22 is a calculation unit that implements the function of comparing the magnitude of analog quantities. When the current opening degree of the bypass regulating valve is less than the second threshold, it outputs a high-level signal, and otherwise outputs a low-level signal.

[0036] The first comparison unit 21 receives the current opening degree of the bypass regulating valve output by the parameter acquisition module 1 in real time, compares it with the first threshold, and outputs the first comparison result. When the current opening degree of the bypass regulating valve is greater than the first threshold, it means that the bypass regulating valve has reached the upper limit of its optimal regulation range, and the gas unit is experiencing a load increase and insufficient regulation capacity of the bypass regulating valve. At this time, the first comparison unit 21 outputs a high-level first comparison result, indicating that the bypass regulating valve needs to be triggered to switch the main regulating valve; otherwise, it outputs a low-level first comparison result, determining that the current bypass regulating valve is still in the effective regulation range and does not trigger the switching.

[0037] The second comparison unit 22 receives the current opening degree of the bypass regulating valve output by the parameter acquisition module 1 in real time, compares it with the second threshold, and directly outputs the second trigger signal. When the current opening degree of the bypass regulating valve is less than the second threshold, it indicates that the current load of the gas turbine unit is low or the main regulating valve is abnormal. At this time, the second comparison unit 22 outputs a high-level second trigger signal to trigger the main regulating valve to switch the bypass regulating valve; otherwise, it outputs a low-level second trigger signal to determine that there is no need to switch the regulating valve at present.

[0038] Continue to refer to Figure 2To further improve the stability of the control system and achieve bidirectional, disturbance-free switching between the main control valve and the bypass control valve, the switching execution module 3 in this embodiment includes a pulse unit 31, a reset (SR) trigger 32, a third switching unit 33, and a fourth constant A4. The fourth constant A4 is the fixed opening of the main control valve. The input terminal of the pulse unit 31 is connected to the output terminal of the comparison unit 23. The set terminal S of the SR trigger 32 is connected to the output terminal of the pulse unit 31. The reset terminal R of the SR trigger 32 is connected to the output terminal of the second comparison unit 22. The output terminal of the SR trigger 32 is connected to the enable terminal of the third switching unit 33. The first input terminal N of the third switching unit 33 receives the opening command of the bypass control valve. The second input terminal Y of the third switching unit 33 is connected to the fourth constant A4. The third switching unit 33 selects either the bypass control valve opening command or the fourth constant A4 as the first control command based on the output of the SR trigger 32.

[0039] Specifically, the SR trigger 32 includes a set terminal S, a reset terminal R, and an output terminal Q. When the signal received by the reset terminal R is low, the output terminal Q outputs the level received by the set terminal S. When the signal received by the reset terminal R is high, the output terminal Q directly outputs a low level. The third switching unit 33 controls the output channel through the enable terminal. When the enable terminal is high, it outputs the signal received by the second input terminal Y, that is, it outputs the fourth constant A4. When the enable terminal is low, it outputs the signal received by the first input terminal N, that is, it outputs the bypass regulating valve opening command.

[0040] In this embodiment, the output terminal Q of the SR flip-flop 32 is connected to the enable terminal of the third switching unit 33. When the second trigger signal received by the reset terminal R of the SR flip-flop 32 is low, the output terminal Q of the SR flip-flop 32 outputs the signal received by the set terminal S to the enable terminal of the third switching unit 33. Otherwise, it directly outputs a low level to the enable terminal of the third switching unit 33.

[0041] Under normal operating conditions of the gas turbine unit, i.e., when the current opening of the bypass regulating valve is less than the first threshold and greater than the second threshold, both the first and second trigger signals are low, the output terminal Q of the SR trigger 32 outputs a low level, the enable terminal of the third switching unit 33 receives a low level, and the third switching unit 33 outputs the bypass regulating valve opening command received at the first input terminal N as the first control command to continuously adjust the opening of the bypass regulating valve; when the gas turbine unit experiences load increase and the bypass regulating valve's adjustment capacity is insufficient, the first trigger signal is high, the second trigger signal is low, and the output terminal Q of the SR trigger 32... A high-level output is sent to the enable terminal of the third switching unit 33. At this time, the third switching unit 33 outputs the fourth constant A4 to adjust the opening of the main control valve and stop receiving the opening command of the bypass control valve, thereby realizing the switching of the bypass control valve to the main control valve. When the current load of the gas turbine unit is low or the main control valve is abnormal, the first trigger signal is low and the second trigger signal is high. The output terminal Q of the SR trigger 32 outputs a low level to the enable terminal of the third switching unit 33. At this time, the third switching unit 33 outputs the opening command of the bypass control valve to adjust the opening of the bypass control valve, thereby realizing the switching of the main control valve to the bypass control valve.

[0042] Continue to refer to Figure 2 In this embodiment, the rate setting module 5 includes a first constant A1, a second constant A2, and a subtraction unit 51, a third comparison unit 52, a delay unit 53, and a first switching unit 56 connected in sequence. The subtraction unit 51 is used to calculate the difference between the high-pressure steam drum liquid level setting value and the current liquid level of the high-pressure steam drum. The third comparison unit 52 is used to determine whether the difference is within a preset range. The first input terminal N of the first switching unit 56 is connected to the first constant A1, the second input terminal Y of the first switching unit 56 is connected to the second constant A2, and the enable terminal of the first switching unit 56 is connected to the output terminal of the third comparison unit 52. The first switching unit 56 selects either the first constant A1 or the second constant A2 as the opening change rate according to the output of the third comparison unit 52. The second constant A2 is greater than the first constant A1.

[0043] Specifically, in this embodiment, the subtraction unit 51 receives and calculates the difference between the high-pressure steam drum liquid level setpoint and the current liquid level of the high-pressure steam drum in real time, and then outputs the difference to the third comparison unit 52; the third comparison unit 52 compares the difference with a preset range, which can be -50mm to 50mm. When the difference exceeds the preset range, the third comparison unit 52 outputs a high-level signal to the delay unit 53; the delay unit 53 performs anti-jitter delay on the high-level signal. If the high-level duration exceeds the preset delay time, it outputs a high-level signal to the first switching unit 5. The enable terminal of 6 outputs a low-level signal, and the enable terminal outputs a low-level signal. The first switching unit 56 selects the rate limit according to the enable terminal signal: when the enable terminal is low, it means that the current liquid level of the high-pressure steam drum is normal and the gas turbine unit is in normal operating condition, and outputs the small rate limit of the first constant A1; when the enable terminal is high, it means that the current liquid level of the high-pressure steam drum is abnormal, and outputs the large rate limit of the second constant A2. This ensures that the regulating valve operates faster under abnormal operating conditions and improves the response of the control system. For example, the first constant A1 can be 0.5% / s and the second constant A2 can be 2% / s.

[0044] To further enhance the adaptability and practicality of the control system under various operating conditions, this embodiment adds a manual access control valve switching method. The rate setting module 5 also includes a non-interceptor 57, a second switching unit 58, and a third constant A3. The non-interceptor 57 is used to invert the switching state of the bypass control valve, and the output terminal of the non-interceptor 57 is connected to the enable terminal of the second switching unit 58. The first input terminal of the second switching unit 58 is connected to the output terminal of the first switching unit 56, and the second input terminal of the second switching unit 58 is connected to the third constant A3. The second switching unit 58 selects either the output of the first switching unit 56 or the third constant A3 as the opening change rate based on the output of the non-interceptor 57.

[0045] Specifically, the bypass control valve switching state refers to the switching signal of the bypass control valve switching operation manually triggered by the operator. In this embodiment, the non-unit 57 receives the bypass control valve switching state signal in real time, performs an inversion operation on the signal, and outputs it to the enable terminal of the second switching unit 58. When the operator does not trigger manual switching, the bypass control valve switching state is high level. After being inverted by the non-unit 57, it outputs a low level to the enable terminal of the second switching unit 58. The second switching unit 58 outputs the output value of the first switching unit 56, which is the rate limit in automatic mode. When the operator triggers manual switching, the bypass control valve switching state is low level. After being inverted by the non-unit 57, it outputs a high level to the enable terminal of the second switching unit 58, which outputs a third constant A3. The third constant A3 is the rate limit adapted to the manual switching condition. For example, the third constant A3 can be 0.3% / s to ensure a smooth and undisturbed manual switching process.

[0046] In another possible implementation, to achieve a smooth and seamless switching between the main control valve and the bypass control valve, the instruction output module 4 in this embodiment includes a rate limiting unit 41; the instruction input terminal IN of the rate limiting unit 41 is connected to the output terminal of the switching execution module 3. The rate limiting unit 41 The rate limit input terminal RALM is connected to the output terminal of the rate setting module 5. The rate limiting unit 41 The output terminal and the Driver Module 6 connect.

[0047] Specifically, the instruction input terminal IN of the rate limiting unit receives the first control instruction output by the switching execution module 3, and the rate limit input terminal RALM receives the opening change rate output by the rate setting module 5. The first control instruction is smoothed according to the set maximum allowable change rate. When the first control instruction has a step change, the rate limiting unit 41 will not directly output a step value, but will linearly adjust the output value to the target opening according to the set opening change rate, and finally output a smoothly changing second control instruction to the driving module 6 of the regulating valve to drive the regulating valve to operate smoothly.

[0048] On the other hand, this application also provides a high-pressure feedwater regulating valve control device for the start-up and shutdown phase of a gas turbine unit, including the high-pressure feedwater regulating valve control system for the start-up and shutdown phase of a gas turbine unit as described above.

[0049] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0050] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A high-pressure feedwater regulating valve control system for the start-up and shutdown phases of a gas turbine unit, characterized in that, include: The module includes a parameter acquisition module, a logic determination module, a switching execution module, an instruction output module, a rate setting module, and a driver module. The parameter acquisition module is used to acquire real-time operating parameters of the gas turbine unit and status parameters of the regulating valves, including a main regulating valve and a bypass regulating valve. The input terminal of the logic determination module is connected to the output terminal of the parameter acquisition module, and is used to determine whether to switch the control valve based on the control valve status parameters and preset control valve switching conditions, so as to obtain a switching control signal. The input terminal of the switching execution module is connected to the output terminal of the logic determination module, and is used to generate a first control command based on the switching control signal; The input terminal of the rate setting module is connected to the output terminal of the parameter acquisition module, and is used to generate the opening change rate based on the operating parameters of the gas turbine unit; The first input terminal of the instruction output module is connected to the output terminal of the switching execution module, the second input terminal is connected to the output terminal of the rate setting module, and the output terminal of the instruction output module is connected to the regulating valve. It is used to generate a second control instruction based on the first control instruction and the opening change rate, and output the second control instruction to the drive module. The drive module is connected to the main control valve and the bypass control valve, and the drive module is used to drive the main control valve and the bypass control valve according to the second control command.

2. The high-pressure feedwater regulating valve control system for the start-up and shutdown phase of a gas turbine unit according to claim 1, characterized in that, The operating parameters of the gas turbine unit include: the high-pressure steam drum liquid level setpoint, the current liquid level of the high-pressure steam drum, and the switching status of the bypass regulating valve; The regulating valve status parameters include: bypass regulating valve opening command, bypass regulating valve automatic status, bypass regulating valve current opening, and main regulating valve automatic status; The main regulating valve includes a 100% capacity regulating valve; the bypass regulating valve includes a 30% capacity regulating valve.

3. The high-pressure feedwater regulating valve control system for the start-up and shutdown phase of a gas turbine unit according to claim 2, characterized in that, The switching conditions for the regulating valve include the conditions for switching the main regulating valve to the bypass regulating valve and the conditions for switching the bypass regulating valve to the main regulating valve. The conditions for switching the main control valve to the bypass control valve include: the main control valve is in automatic mode, the bypass control valve is in automatic mode, and the current opening degree of the bypass control valve is greater than a first threshold. The conditions for the bypass regulating valve to switch to the main regulating valve include: the main regulating valve is in automatic mode, the bypass regulating valve is in automatic mode, and the current opening degree of the bypass regulating valve is less than the second threshold.

4. The high-pressure feedwater regulating valve control system for the start-up and shutdown phase of a gas turbine unit according to claim 3, characterized in that, The first threshold is greater than the second threshold.

5. The high-pressure feedwater regulating valve control system for the start-up and shutdown phase of a gas turbine unit according to claim 3, characterized in that, The logic determination module includes a first comparison unit, a second comparison unit, and an AND unit; The first comparison unit is a greater than comparison unit, and the second comparison unit is a less than comparison unit; The switching control signal includes a first trigger signal and a second trigger signal. When the first trigger signal is high, it triggers the bypass regulating valve to switch the main regulating valve. When the second trigger signal is high, it triggers the main regulating valve to switch the bypass regulating valve. The first comparison unit is used to compare the current opening of the bypass regulating valve with the first threshold; the AND unit is used to perform an AND operation on the automatic state of the main regulating valve, the automatic state of the bypass regulating valve, and the comparison result of the first comparison unit, and output a first trigger signal. The second comparison unit is used to compare the current opening degree of the bypass regulating valve with the second threshold and output a second trigger signal.

6. The high-pressure feedwater regulating valve control system for the start-up and shutdown phase of a gas turbine unit according to claim 5, characterized in that, The switching execution module includes a pulse unit, an SR trigger, a third switching unit, and a fourth constant; The fourth constant is the fixed opening degree of the main control valve; The input terminal of the pulse unit is connected to the output terminal of the AND unit, the set terminal of the SR flip-flop is connected to the output terminal of the pulse unit, the reset terminal of the SR flip-flop is connected to the output terminal of the second comparison unit, the output terminal of the SR flip-flop is connected to the enable terminal of the third switching unit, the first input terminal of the third switching unit receives the opening command of the bypass regulating valve, and the second input terminal of the third switching unit is connected to the fourth constant. The third switching unit selects either the bypass regulating valve opening command or the fourth constant as the first control command based on the output of the SR trigger.

7. The high-pressure feedwater regulating valve control system for the start-up and shutdown phase of a gas turbine unit according to claim 6, characterized in that, The rate setting module includes a first constant, a second constant, and a subtraction unit, a third comparison unit, a delay unit, and a first switching unit connected in sequence. The subtraction unit is used to calculate the difference between the high-pressure steam drum liquid level set value and the current liquid level of the high-pressure steam drum, and the third comparison unit is used to determine whether the difference is within a preset range; The first input terminal of the first switching unit is connected to the first constant, the second input terminal of the first switching unit is connected to the second constant, and the enable terminal of the first switching unit is connected to the output terminal of the third comparison unit. The first switching unit selects a first constant or a second constant as the opening change rate based on the output of the third comparison unit; The second constant is greater than the first constant.

8. The high-pressure feedwater regulating valve control system for the start-up and shutdown phase of a gas turbine unit according to claim 7, characterized in that, The rate setting module also includes a non-unit, a second switching unit, and a third constant; The non-unit is used to invert the switching state of the bypass regulating valve, and the output terminal of the non-unit is connected to the enable terminal of the second switching unit. The first input terminal of the second switching unit is connected to the output terminal of the first switching unit, and the second input terminal of the second switching unit is connected to the third constant. The second switching unit selects either the output of the first switching unit or the third constant as the opening change rate based on the output of the non-unit.

9. The high-pressure feedwater regulating valve control system for the start-up and shutdown phase of a gas turbine unit according to claim 1, characterized in that, The instruction output module includes a rate limiting unit; the instruction input terminal of the rate limiting unit is connected to the output terminal of the switching execution module, the rate limit input terminal of the rate limiting unit is connected to the output terminal of the rate setting module, and the output terminal of the rate limiting unit is connected to the drive module.

10. A high-pressure feedwater regulating valve control device for the start-up and shutdown phases of a gas turbine unit, characterized in that, The high-pressure feedwater regulating valve control system for the start-up and shutdown phase of a gas turbine unit, as described in any one of claims 1-9.

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