Water vapor electric heating all-working-condition one-key starting control method for combined cycle generator set

Abstract

The invention provides a water vapor electric heating all-condition one-key start control method for a combined cycle generator set, and belongs to the technical field of automatic control of the combined cycle generator set. Aiming at the problems that an existing APS system is multiple in breakpoint, poor in adaptability, complex in operation and the like, the method integrates cooperative control logic of a water circulation system, a steam system, an electric power system and a thermal power system, a cold / temperature / thermal state all-working-condition self-adaptive starting curve is built in, and breakpoint-free automatic operation of gas turbine ignition, waste heat boiler temperature and pressure rising, steam turbine impulse running grid connection and heat supply switching is achieved. The core innovation comprises bypass multi-mode self-adaptive control, steam drum water level sectional type adjustment, automatic steam supply switching and cross-system undisturbed communication, real-time monitoring of 400 + key parameters and setting of multi-stage safety protection. After the method is implemented, the cold starting time is shortened, the manual misoperation risk is reduced, the main steam temperature fluctuation is controlled within + / -5 DEG C, the unit starting efficiency, safety and economical efficiency are remarkably improved, and the method is suitable for all-working-condition starting scenes of E-level and above combined cycle generator units.

Description

Technical Field

[0001] This invention belongs to the field of automation control technology for combined cycle generator sets, and more specifically, it relates to a one-button start control method for combined cycle generator sets under all operating conditions of water, steam, electricity and heat. Background Technology

[0002] Gas-steam combined cycle generator sets have become a core peak-shaving power source for the power grid due to their flexible start-stop and environmental friendliness. However, their frequent start-stop cycles (over 300 times per year) and multi-system coupling characteristics place extremely high demands on automated start-up technology. Currently, the industry's APS (Automatic Start-up System) technology faces the following key challenges:

[0003] Fragmented control mode: Most domestic units use breakpoint segmented control in their APS. For example, the early system of Huaneng Tongxiang required manual activation of each system-level sequential control (condensate, shaft seal, circulating water, etc.). There were more than 120 manual intervention steps during the cold start process, and complex operations such as steam injection and bypass adjustment still relied on manual operation, making it impossible to achieve "true one-button" start-up. The start-up time was as long as 210 minutes, far exceeding the 180 minutes after manual optimization.

[0004] Poor adaptability to all operating conditions: The existing system has not optimized the control logic for the differences in cold / warm / hot start-up. For example, when starting in warm condition, the threshold of "high pressure main steam valve drain temperature > 300℃" is still used in cold condition, resulting in redundant start-up preparation time. In addition, the interface protocols between the gas turbine and the steam turbine and waste heat boiler are not transparent (such as communication delay between GTCS and DCS), and the timing deviation of cross-system operation reaches 10-15s, which can easily cause steam drum water level fluctuation (±30mm) or main steam pressure overshoot (±0.1MPa).

[0005] Core subsystem control defects: The bypass system is mostly a single pressure stabilization mode. When the supplementary steam is put into operation, the bypass closure and the supplementary steam opening lack coordination, resulting in medium-pressure main steam pressure fluctuations exceeding ±0.05MPa; the steam drum water level control does not distinguish between the "water filling-operation" stage, and the high-pressure steam drum water level deviation often exceeds ±20mm, requiring frequent manual intervention; the heating switching relies on manually shutting down the gas boiler and opening the extraction steam valve, and the heat loss during the switching process reaches 8-12%.

[0006] Insufficient reliability and economy: Due to poor equipment compatibility (such as low matching degree between domestic waste heat boilers and imported gas turbines), the failure rate of APS system exceeds 70% within two years of commissioning; and it does not integrate self-learning optimization function, so it cannot correct control parameters (such as steam replenishment rate and water level offset) based on historical data, resulting in fuel consumption differences of 5-8% for each start-up, with an average annual start-up cost of over 2 million yuan.

[0007] In summary, existing technologies are insufficient to meet the requirements of one-button start-up for combined cycle units under all operating conditions, with high reliability and low cost. There is an urgent need to develop an intelligent control method that covers multiple systems including water, steam, electricity and heat and has adaptive capabilities under all operating conditions. Summary of the Invention

[0008] To address the aforementioned technical problems, this invention provides a one-button start-up control method for combined cycle generator sets under all operating conditions of water, steam, electricity, and heat. This method solves the technical problems of existing combined cycle generator set APS one-button start-up technology, such as frequent manual intervention required for breakpoint control, poor adaptability to all operating conditions (cold / warm / hot), difficulty in coordinating multiple water, steam, electricity, and heat systems, large fluctuations in core parameters such as main steam pressure and steam drum water level, slow peak-shaving response, and low start-up economy.

[0009] The one-button start control method for combined cycle generator sets under all operating conditions (water, steam, electricity, and heat) includes the following steps:

[0010] Upon receiving the one-click start command, it automatically completes the confirmation of the device's pre-selected status and the verification of the start-up permission conditions;

[0011] Based on the preset full-condition adaptive control logic, the coordinated control commands of the water circulation system, steam system, power system and thermal system are activated in sequence;

[0012] The entire process of gas turbine ignition, waste heat boiler heating and pressurization, steam turbine commissioning and grid connection, and heating system switching is automated through a hierarchical sequential control mechanism.

[0013] Real-time monitoring of over 400 key operating parameters, and correction of the start-up curve through dynamic parameter matching algorithms, ensuring that the main steam temperature, cylinder thermal stress and load increase rate are within safe thresholds;

[0014] After the sequential control is completed, the start-up interlock will automatically exit, completing the seamless one-button start-up of the unit from cold / warm state to full load operation.

[0015] Preferably, the hierarchical sequential control mechanism includes three levels of control modules: unit coordination level, subgroup level, and equipment level. The coordination level sequential control is responsible for issuing global instructions and monitoring progress. The subgroup level sequential control activates the sequential control function group of the corresponding system. The equipment level sequential control executes the start-up and shutdown operations and fault isolation of individual equipment. When any equipment level sequential control fails, the fault handling process is triggered and the continuous operation of non-faulty equipment is maintained.

[0016] Preferably, the steam system control includes bypass multimodal adaptive control, preset bypass constant sliding pressure mode, temperature and pressure rise control mode and steam injection mode. When medium-pressure steam injection is activated, the steam injection valve opens at a preset rate at a uniform speed, and the bypass valve dynamically adjusts its closing speed according to the main steam pressure and water level change rate. The coordinated linkage between steam injection and bypass is achieved through PID closed-loop control.

[0017] Preferably, the power system control includes the automatic turbine start-up and grid connection process. Before start-up, the high-pressure main steam valve body drain valve downstream temperature is verified to be >220℃ and the condenser vacuum is <-75kPa. During start-up, the turbine is automatically accelerated to 3000rpm at a rate of 600rpm / min. After the constant speed condition is met, the generator is automatically synchronized. After grid connection is completed, the valve position control mode is activated.

[0018] Preferably, the water circulation system control includes segmented control of the water levels in the high, medium, and low pressure steam drums. During the startup phase, the water level is controlled by a stepped water supply strategy. During normal operation, an automatic water level control interlock is activated. When the high pressure steam drum water level is >-80mm, the continuous sewage discharge electric valve is automatically opened, and when it is <-160mm, it is automatically closed, thus achieving precise water level regulation.

[0019] Preferably, the thermal system control includes sequential control of steam extraction heating from the gas boiler to the steam turbine. When the unit meets the conditions of GCB closing, medium-pressure steam injection valve opening > 60%, and gas turbine load > 120MW, the extraction steam drain valve group is automatically opened, the extraction steam electric regulating valve is opened at a fixed rate, the gas boiler is shut down and the corresponding drain valve is closed simultaneously, so as to achieve seamless switching of heating mode.

[0020] Preferably, the full-condition adaptive control logic has three built-in start-up modes: cold, warm, and hot. It automatically matches the start-up curve by identifying the steam pressure in front of the gas turbine high-pressure main steam valve and the cylinder temperature. In the warm start-up mode, the valve body drain temperature threshold of the high-pressure main steam valve is optimized to 220°C, which shortens the start-up preparation time.

[0021] Preferably, the coordinated control command includes a non-interference communication mechanism between the gas turbine GTCS and DCS systems. The GTCS system is responsible for gas turbine ignition and speed control, while the DCS system coordinates the operation of the waste heat boiler, steam turbine, and auxiliary systems. The command is transmitted synchronously and the status is fed back through a preset communication protocol to ensure the consistency of the operation sequence across systems.

[0022] Preferably, the key parameter monitoring includes core indicators such as high-pressure main steam pressure, steam drum water level, condenser vacuum and shaft seal pressure, and sets up a multi-level safety protection mechanism. When the deviation between the high-pressure main steam pressure and the bypass set value is >0.5MPa, the steam injection operation is suspended.

[0023] When the pressure in the equalizing chamber is less than 42 kPa, the shaft seal self-sealing switching process is suspended.

[0024] Preferably, it also includes a self-learning optimization module, which builds a big data model by collecting historical startup data, dynamically corrects the steam injection rate, bypass adjustment parameters and steam drum water level offset value, and automatically updates the control parameter library after each startup cycle, thereby improving the stability and economy of the startup process under different operating conditions.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] Start-up efficiency is significantly improved, and peak-shaving response capability is enhanced: Through full-condition adaptive start-up curve optimization (such as reducing the high-pressure main steam valve condensate temperature threshold from 300℃ to 220℃ during warm-state start-up) and cross-system non-interference communication (GTCS and DCS command synchronization deviation <2s), the cold start-up time is shortened from 210min to 180min, and the warm start-up time is shortened from 150min to 120min, with the overall start-up time reduced by 15-20%. At the same time, 115 manual operation steps are eliminated, and the unit's response time from "receiving the start-up command" to "full-load operation" is shortened by 30%, which can quickly match the grid's peak-shaving demand, especially suitable for areas with large power load fluctuations such as Zhejiang (the average number of peak-shaving responses per year is increased by 40%).

[0027] Operational reliability is significantly improved, and human error risks are minimized: The hierarchical sequential control and fault isolation mechanism enables continuous operation of non-faulty equipment. For example, if an open pump fails to start, only that equipment is isolated and the backup pump is automatically started, without affecting the overall sequential control of the circulating water system. With real-time monitoring of 400+ key parameters (such as suspending steam injection when the high-pressure main steam pressure deviation exceeds 0.5MPa), the risk of human error is reduced by 90%, and the equipment failure rate is reduced from 4% to 1.2%. Moreover, the sequential control process is fully automated, and operators only need to issue a "one-click start" command and confirm the fault (the number of manual operation steps is reduced from 120 to 5), greatly reducing labor intensity.

[0028] Precise control of operating parameters extends equipment life: Bypass multi-modal control (constant sliding pressure / heating and pressure increase / steam injection mode) narrows the pressure fluctuation of medium-pressure main steam from ±0.1MPa to ±0.03MPa; segmented regulation of steam drum water level (step control during water filling stage + interlocking protection during operation stage) controls the deviation of high-pressure steam drum water level from ±30mm to within ±10mm, and the low-pressure steam drum water level >-260mm and medium-pressure >-200mm, avoiding steam drum fatigue damage caused by large water level fluctuations; the high-pressure main steam temperature fluctuation is optimized from ±15℃ to ±5℃, the cylinder thermal stress is controlled within the allowable threshold, the life loss of the high-pressure cylinder of the steam turbine is reduced by 25%, and the life of the waste heat boiler piping system is extended by more than 3 years.

[0029] Significant economic benefits, with a double reduction in energy consumption and costs: automatic steam injection and seamless switching of heating (heat loss from gas boiler to turbine extraction steam reduced from 12% to 4%), combined with a self-learning optimization module (correcting the steam injection rate and bypass parameters based on historical data), saving 120 Nm³ of natural gas per startup. 3The annual start-up cost is reduced by RMB 1.08 million, and due to stable parameters (such as condensate header pressure > 1.5MPa and open pump outlet pressure > 0.23MPa), the auxiliary power consumption rate is reduced by 0.3%, resulting in annual power savings of approximately 120,000 kWh. At the same time, the gas boiler shutdown interlock (automatic shutdown of feedwater pump after both boilers are shut down) reduces ineffective energy consumption, and fuel consumption during the heating season is reduced by 8%.

[0030] Full operating condition coverage and flexible expansion, with wide applicability: It has three built-in start-up modes: cold / warm / hot. It automatically identifies the operating condition and matches the start-up curve through the pressure in front of the gas turbine high-pressure main steam valve (12MAA10CP101), without the need for manual switching. The modular design (basic control unit + extended function module) supports different unit configurations (such as extraction condensing / back pressure steam turbines, three-pressure / single-pressure waste heat boilers). It can be directly adapted to E-class / F-class combined cycle units. When adding equipment, only the corresponding module needs to be connected (such as when adding a gas boiler, no change to the overall logic is required). The adaptation cost is reduced by 60%, which has industry promotion value. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the method flow of the present invention. Detailed Implementation

[0032] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0033] Please see Figure 1 This invention discloses a one-button start-up control method for combined cycle generator units operating under all water, steam, electricity, and heat conditions. Designed based on the actual operational requirements of the #1 combined cycle unit (configured with a GT13E2 gas turbine, a three-pressure waste heat boiler without supplementary combustion, an extraction condensing turbine, and a back-pressure turbine) at Huaneng Tongxiang Gas Turbine Power Co., Ltd., it achieves seamless one-button start-up of the unit from cold / warm / hot states to full-load operation through hierarchical sequential control, multi-system coordination, and full-condition adaptive logic. The implementation process of this invention is described in detail below, combining specific equipment parameters, control timing, and operational details.

[0034] This embodiment focuses on a combined cycle unit with a total installed capacity of 51.64MW, comprising a multi-energy coupled system of gas turbine + waste heat boiler + steam turbine + generator set + gas boiler heating. Key equipment parameters are as follows:

[0035] Gas turbine: Model GT13E2, rated speed 3000rpm, load increases to 135MW in 45 minutes after ignition;

[0036] Waste heat boiler: Three-pressure natural circulation type, with a high-pressure steam drum design pressure of 6.86MPa, medium-pressure of 3.5MPa, and low-pressure of 0.2MPa;

[0037] Steam turbine: extraction condensing type, starting speed 3000rpm, rated vacuum -90kPa;

[0038] Heating system: includes 2 gas-fired boilers (rated evaporation capacity 20t / h) and steam extraction pipelines for the steam turbine, with a switching pressure of 1.15MPa.

[0039] This method integrates the sequential control logic of four major systems—water circulation, steam, electricity, and heat—through seamless communication between the DCS (Distributed Control System) and the GTCS (Gas Turbine Control System). It incorporates over 400 key parameter monitoring points and 12 sets of interlocking protection mechanisms to achieve full-process automation.

[0040] One-click start of the overall control process:

[0041] After the operator issues the "one-click start" command on the APS main screen, the system will execute the following steps (total time: approximately 180 minutes for cold start, approximately 120 minutes for warm start):

[0042] Start-up preparation verification: Automatically detect the "equipment pre-selection confirmation" status (such as whether the pre-selected equipment, such as condensate pump A / B and open pump A / B, is ready). After verifying that there are no defects in the start-up preparation, proceed to the start-up allowable condition judgment (such as circulating water pump suction well liquid level > 1.8m, EH oil tank oil level > 400mm, etc.).

[0043] System-level sequential control activation: Subgroup sequential control is activated in the order of water circulation → steam system → power system → thermal system. The sequential control of each subgroup is linked by hierarchical commands (e.g., after the sequential control of the condensate system is completed, the sequential control of water supply to the low-pressure steam drum is automatically triggered).

[0044] Full operating condition parameter adaptation: Real-time identification of unit status (cold state: main steam valve pressure < 0.5MPa; warm state: 0.5-1.1MPa; hot state: > 1.1MPa), automatically matching the corresponding start-up curve (e.g., the high-pressure main steam valve drain temperature threshold drops to 220℃ during warm state start-up);

[0045] Safety closed-loop control: Before each sequential control step is executed, the preconditions are checked (e.g., the sequential control of the shaft seal system requires the condensate system to be completed), during execution, the parameter deviation is monitored (e.g., if the deviation between the high pressure main steam pressure and the set value is >0.5MPa, the operation is suspended), and after execution, the feedback is confirmed (e.g., the vacuum pump is running and the vacuum is <-82kPa).

[0046] Sequential control completion: After the unit is connected to the grid and the load is >135MW, it automatically exits the start-up interlock (including 7 sets of interlocks such as condenser water level control and automatic steam drum water level control) and completes one-button start-up.

[0047] Specific implementation of the hierarchical control mechanism:

[0048] This invention adopts a three-level sequential control architecture: coordination level, subgroup level, and device level. The specific implementation is as follows:

[0049] Coordination-level sequential control (unit level): global command issuance and progress monitoring, deployed in the APS main sequential control module of the DCS system;

[0050] Implementation steps: After receiving the one-button start command, first activate "Main Sequential Control Step 1" (start the condensate, shaft seal, circulating water and other systems). After all feedback from Step 1 is satisfied (such as the condensate system is completed and the shaft seal pressure is >35kPa), activate "Main Sequential Control Step 2" (start the EH oil system) after a 10-second delay, and so on up to Step 7 (high-pressure main steam switching and heating switching).

[0051] Troubleshooting: When a subgroup fails to start (e.g., an open pump fails to start), the coordination-level sequential control pauses the current step and displays a pop-up window indicating the fault point (e.g., "Open pump A outlet pressure < 0.23 MPa"). After the operator troubleshoots the fault, clicking "Continue" will restore the sequential control, and the non-faulty subgroups will continue to operate.

[0052] Subgroup-level sequential control (system level):

[0053] Taking the sequential control of a circulating water system as an example, the specific implementation steps are as follows:

[0054] Start-up verification: Confirm that the liquid level after the filter screen of the #1 / #2 suction well of the circulating water pump is >1.8m;

[0055] Step 1 instruction: Open the circulating water inlet electric valve (00PAB20AA002) and return water electric valve (00PAB40AA001), and confirm that the valves are fully open and the open pump bypass valve is open / any open pump is running.

[0056] Step 2 instruction: Open the electric valve on the A / B side of the condenser circulating water outlet and confirm that the valve is fully open;

[0057] Step 3 instructions: Open the electric valves on the A / B side of the condenser circulating water inlet and the electric valve for the pre-selected cooling tower water supply, and confirm that the valves are fully open;

[0058] Step 4 instruction: Start the pre-selected circulating water pump sequential control subgroup and confirm that any circulating pump is running (outlet hydraulic control valve fully open and pressure > 0.1MPa);

[0059] Step 5 instruction: Start the corresponding cooling tower fan (start after the water inlet valve is fully opened), confirm the fan is running and delay for 30 seconds;

[0060] Step 6 Instruction: Put the backup circulating pump into standby mode and confirm that the backup signal is normal;

[0061] Step 7 Instruction: Stop the auxiliary machine cooling water pump, close the auxiliary cooling water inlet and outlet valves, and confirm that the pump has stopped and the valves are closed.

[0062] Equipment-level sequential control (single device):

[0063] Taking the start-up of the condensate pump as an example, the specific implementation steps are as follows:

[0064] Prerequisites: Condensate system preparation and control step six activation; iron removal filter inlet and outlet valves are open.

[0065] Start-up command: Open the condensate pump inlet electric valve → Start the pump → Open the outlet electric valve;

[0066] Feedback verification: Confirm pump operation signal, outlet pressure > 0.8MPa, condensate header pressure > 1.5MPa;

[0067] Fault isolation: If the outlet pressure does not reach the target within 10 seconds after the pump starts, the pump will automatically stop and the inlet and outlet valves will be closed, triggering the "standby pump start" command, without affecting other operations of the condensate system.

[0068] Core control strategies for each system:

[0069] Water circulation system control:

[0070] The key is to achieve segmented and precise control of the water level in the high, medium, and low-pressure steam drums. Specific implementation details include:

[0071] Water supply phase (step one to step two):

[0072] Low-pressure steam drum: If the water level is <-300mm, manually open the regulating valve 50%; for -300 to -200mm, open 15%; for >-200mm, open 10% and then switch to automatic (offset -150mm), and finally the water level >-260mm.

[0073] Medium-pressure steam drum: Select medium-pressure feedwater pump A / B, after startup the outlet pressure is >3.5MPa. If the water level is <-300mm, open the regulating valve 45%. After automatic operation, the water level is >-200mm.

[0074] High-pressure steam drum: Start the high-pressure feedwater pump (outlet pressure > 4.5MPa). If the water level is < -600mm, open the regulating valve to 40%. After automatic operation, the water level will be > -260mm.

[0075] Operational phase (water level interlocking activated):

[0076] High-pressure steam drum: The continuous drain valve opens automatically when the water level is >-80mm and closes when it is <-160mm; the evaporator drain valve opens when the water level is >-20mm and closes when it is <-150mm.

[0077] Low-pressure steam drum: Open the evaporator drain valve when the water level is >-80mm, and close it when the water level is <-160mm;

[0078] Interlock protection: When the condenser liquid level is >1050mm and the low-pressure feedwater flow rate is <80t / h, the water supply regulating valve will be manually closed to 0% and then put into automatic mode (SP=1000mm).

[0079] Steam system control:

[0080] The core is bypass multimodal control and automatic activation / deactivation of supplementary steam, specifically implemented as follows:

[0081] Bypass control:

[0082] Constant sliding pressure mode: When the gas turbine load is <80MW, the low bypass valve setting value = current pressure - 0.025MPa, and the medium bypass valve = current pressure - 0.035MPa;

[0083] Heating and pressurization mode: When the high-pressure steam is heated, the high-pressure bypass valve is set to automatic (minimum valve position 5% when pressure > 0.5MPa). In constant pressure mode, the set value = bypass pressure - 0.2MPa.

[0084] Steam replenishment mode: When the medium-pressure steam replenishment is activated, the steam replenishment regulating valve opens at a rate of 5% / min, and the bypass regulating valve closes according to the main steam pressure change rate (decelerates when >0.05MPa / min) to ensure that the pressure fluctuation is <±0.03MPa;

[0085] Gas replenishment and withdrawal:

[0086] Low-pressure steam replenishment: After the inlet temperature is greater than the saturation temperature by 11℃, the unit power is greater than 20%, and the pressure is 0.08-0.4MPa, open the main steam valve (delay for 20s), the regulating valve opens at a uniform speed, and the low-pressure bypass regulating valve is put into automatic mode (set value + 0.025MPa).

[0087] Medium-pressure steam replenishment: After the pressure is 0.3-1.5MPa and the steam drum water level is -250 to -80mm, the regulating valve opens (delayed for 30s), and the intermediate bypass regulating valve closes completely at the same time.

[0088] Power system control:

[0089] The key is the automatic start-up and grid connection of the steam turbine, and the specific implementation is as follows:

[0090] Preparations before the spin-up:

[0091] Condition verification: High-pressure main steam valve downstream temperature > 220℃, high-pressure main steam temperature > 300℃, pressure > 2MPa, condenser vacuum < -75kPa, high-pressure inner cylinder temperature difference < 55℃;

[0092] Operation: Click DEH "Open Main Door", confirm that the main steam valve is fully open and the main steam temperature is 30°C higher than the cylinder wall temperature;

[0093] Automatic spooling:

[0094] Speed ​​increase: Click "Start" → "Manual speed increase", enter the target value of 3000rpm and the speed increase rate of 600rpm / min, click "Proceed", and the speed will automatically increase to 2980rpm;

[0095] Constant speed mode: After the speed stabilizes, DEH automatically activates the "constant speed" mode and verifies that the speed deviation is <±5rpm;

[0096] Automatic grid connection:

[0097] Synchronization: In DEH, enable “Synchronization Control” → “Automatic Synchronization” and confirm voltage and frequency matching (voltage deviation < ±5%, frequency deviation < ±0.1Hz);

[0098] Grid connection: Start grid connection sequential control, confirm that the generator outlet switch is closed, and automatically switch to "valve position control" mode.

[0099] Thermal system control:

[0100] The core issue is the switching from gas-fired boiler to steam turbine extraction for heating. Specific implementation details are as follows:

[0101] Switching conditions: #1 steam turbine GCB closed, intermediate pressure auxiliary steam regulating valve opening > 60%, gas turbine load > 120MW;

[0102] Steam trap open:

[0103] After a 5-second delay, the steam extraction drain valve to the condenser is opened; after 10 seconds, the drain valve before the heating steam extraction check valve is opened; after 15 seconds, the drain valve before the quick-closing valve is opened; and after 20 seconds, the drain valve before the steam extraction to the heating header valve is opened.

[0104] Synchronously activate the shutdown sequence control for gas-fired boilers #1 and #2;

[0105] Steam extraction control valve open:

[0106] Open the extraction steam electric regulating valve at a rate of 3% / min, and stop when the steam drum water level is >-80mm or the extraction steam pressure is >1.15MPa;

[0107] When the valve opening is greater than 60% and the temperature is greater than 220℃, close the steam traps sequentially (at 5-second intervals).

[0108] Gas-fired boiler shutdown: After confirming that the steam extraction regulating valve opening is >99%, shut down the gas-fired boiler feedwater pump, close the economizer inlet valve, and manually close the deaerator inlet regulating valve to 0%.

[0109] Implementation of full-condition adaptive and safety protection:

[0110] All-condition adaptive:

[0111] Pattern recognition: The start-up mode is automatically determined based on the steam pressure (12MAA10CP101) before the high-pressure main steam valve of Unit #1.

[0112] Cold state: Pressure < 0.5MPa, execute "auxiliary steam shaft seal sequential control", low-pressure steam drum water regulating valve open 50%;

[0113] Temperature: 0.5-1.1MPa, optimize the high-pressure main steam valve drain temperature to 220℃, and shorten the start-up preparation time by 15min;

[0114] Hot state: >1.1MPa, execute "main steam shaft seal sequential control", open the low-pressure steam drum water regulating valve 15%;

[0115] Curve correction: Based on historical data (such as the timing of the last 10 steam injections and water level regulation deviations), the control parameters are automatically corrected (such as adjusting the steam injection rate from 5% / min to 4.5% / min to reduce pressure fluctuations).

[0116] Security protection mechanism:

[0117] Parameter over-limit protection:

[0118] High-pressure main steam pressure: When the deviation from the bypass set value is >0.5MPa, the supplementary steam supply will be suspended;

[0119] When the pressure in the equalizing chamber is <42 kPa, the shaft seal self-sealing switching is paused.

[0120] Steam drum water level: When the high-pressure steam drum water level is >0mm or <-300mm, the feedwater regulating valve is triggered to close urgently;

[0121] Equipment fault protection:

[0122] Circulating pump reverse: When starting the standby circulating pump, start it directly (without sequential control) to avoid reverse rotation;

[0123] Vacuum pump jamming: If the vacuum is less than -5kPa after 30 seconds of startup, the standby pump will start automatically.

[0124] Interlock Exit Protection: After the sequential control ends, the start interlock will be deactivated after a 10-second delay (to prevent premature deactivation that could prevent the water pump from stopping).

[0125] Implementation effect verification:

[0126] After this method was implemented on Huaneng Tongxiang Unit #1, the key performance indicators are as follows:

[0127] Start-up efficiency: Cold start time is reduced from 210 min to 180 min, and warm start time is reduced from 150 min to 120 min, saving approximately 120 Nm³ of natural gas consumption. 3 / Second-rate;

[0128] Operational reliability: The number of manual operation steps has been reduced from 120 to 5 (only one-click command and fault confirmation are required), reducing the risk of misoperation by 90%;

[0129] Parameter stability: High-pressure main steam temperature fluctuation ±5℃ (originally ±15℃), steam drum water level deviation ±10mm (originally ±30mm);

[0130] Economic benefits: Annual startup costs are reduced by 1.08 million yuan, and heat loss during heating switching is reduced by 8%.

[0131] The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A one-button start control method for combined cycle generator sets under all operating conditions (water, steam, electricity, and heat), characterized in that: Includes the following steps: Upon receiving the one-click start command, it automatically completes the confirmation of the device's pre-selected status and the verification of the start-up permission conditions; Based on the preset full-condition adaptive control logic, the coordinated control commands of the water circulation system, steam system, power system and thermal system are activated in sequence; The entire process of gas turbine ignition, waste heat boiler heating and pressurization, steam turbine commissioning and grid connection, and heating system switching is automated through a hierarchical sequential control mechanism. Real-time monitoring of over 400 key operating parameters, and correction of the start-up curve through dynamic parameter matching algorithms, ensuring that the main steam temperature, cylinder thermal stress and load increase rate are within safe thresholds; After the sequential control is completed, the start-up interlock will automatically exit, completing the seamless one-button start-up of the unit from cold / warm state to full load operation.

2. The control method according to claim 1, characterized in that, The hierarchical sequential control mechanism includes three levels of control modules: unit coordination level, subgroup level, and equipment level. The coordination level sequential control is responsible for issuing global instructions and monitoring progress. The subgroup level sequential control activates the sequential control function group of the corresponding system. The equipment level sequential control executes the start-up and shutdown operations and fault isolation of individual equipment. When any equipment level sequential control fails, the fault handling process is triggered and the continuous operation of non-faulty equipment is maintained.

3. The control method according to claim 1, characterized in that, The steam system control includes bypass multimodal adaptive control, preset bypass constant sliding pressure mode, temperature and pressure rise control mode and steam injection mode. When medium-pressure steam injection is activated, the steam injection valve opens at a preset rate. The bypass valve dynamically adjusts its closing speed according to the main steam pressure and water level change rate. The coordinated linkage between steam injection and bypass is achieved through PID closed-loop control.

4. The control method according to claim 1, characterized in that, The power system control includes the automatic turbine start-up and grid connection process. Before start-up, the temperature after the high-pressure main steam valve body drain valve is >220℃ and the condenser vacuum is <-75kPa. During start-up, the turbine automatically accelerates to 3000rpm at a rate of 600rpm / min. After meeting the constant speed conditions, the generator is automatically synchronized. After grid connection is completed, the valve position control mode is activated.

5. The control method according to claim 1, characterized in that, The water circulation system control includes segmented control of the water levels in the high, medium, and low pressure steam drums. During startup, the water level is controlled by a stepped water supply strategy. During normal operation, an automatic water level control interlock is activated. When the high pressure steam drum water level is >-80mm, the continuous sewage discharge electric valve is automatically opened, and when it is <-160mm, it is automatically closed, thus achieving precise water level regulation.

6. The control method according to claim 1, characterized in that, The thermal system control includes sequential control of steam extraction heating from gas boiler to steam turbine. When the unit meets the conditions of GCB closing, medium-pressure steam injection valve opening > 60% and gas turbine load > 120MW, the extraction steam drain valve group is automatically opened, the extraction steam electric regulating valve is opened at a fixed rate, the gas boiler is shut down and the corresponding drain valve is closed simultaneously, so as to achieve seamless switching of heating mode.

7. The control method according to claim 1, characterized in that, The full-condition adaptive control logic has three built-in start-up modes: cold, warm, and hot. It automatically matches the start-up curve by identifying the steam pressure in front of the high-pressure main steam valve and the cylinder temperature. In the warm start-up mode, the valve body condensate temperature threshold of the high-pressure main steam valve is optimized to 220°C, which shortens the start-up preparation time.

8. The control method according to claim 1, characterized in that, The coordinated control commands include a non-interference communication mechanism between the gas turbine GTCS and DCS systems. The GTCS system is responsible for gas turbine ignition and speed control, while the DCS system coordinates the operation of the waste heat boiler, steam turbine, and auxiliary systems. Through a preset communication protocol, synchronous transmission of commands and status feedback are achieved, ensuring the consistency of cross-system operation timing.

9. The control method according to claim 1, characterized in that, The key parameter monitoring includes core indicators such as high-pressure main steam pressure, steam drum water level, condenser vacuum and shaft seal pressure. A multi-level safety protection mechanism is set up. When the deviation between the high-pressure main steam pressure and the bypass set value is >0.5MPa, the steam injection operation is suspended. When the pressure in the equalizing chamber is less than 42 kPa, the shaft seal self-sealing switching process is suspended.

10. The control method according to claim 1, characterized in that, It also includes a self-learning optimization module, which builds a big data model by collecting historical startup data, dynamically corrects the steam injection rate, bypass adjustment parameters and steam drum water level offset value, and automatically updates the control parameter library after each startup cycle, thereby improving the stability and economy of the startup process under different operating conditions.

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