Automatic switching control method and system for steam source of deaerator in unit starting process

Abstract

The invention relates to the technical field of thermal power generating units, and discloses a control method and system for automatic switching of a steam source of a deaerator in the starting process of a unit, and in the high-speed warming-up stage of a steam turbine, after the switching condition of the steam source of the deaerator is met, automatic switching of the steam source of the deaerator is started through one key. In the process of steam turbine four-stage steam extraction to deaerator pipe warming, after the steam parameters of steam turbine four-stage steam extraction to deaerator reach the standard, it can be confirmed that steam turbine four-stage steam extraction to deaerator pipe warming is completed. And after four-stage steam extraction of the steam turbine is completed to the deaerator heating pipe, slowly opening a four-stage steam extraction electrically operated gate until the four-stage steam extraction electrically operated gate is fully opened, fully opening the four-stage steam extraction electrically operated gate to the deaerator electrically operated gate, slowly closing the auxiliary steam to the deaerator control valve, and fully closing the auxiliary steam to the deaerator electrically operated gate, so that the steam source of the deaerator is switched from the auxiliary steam to four-stage steam extraction of the steam turbine. According to the method, the automation level of the unit is improved, safe operation of the unit in the starting stage is guaranteed, and a good effect is achieved in practical production application.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal power units, and in particular to a method and system for automatically switching a steam source of a deaerator during the startup process of the unit. Background Art

[0002] During unit startup, operators manually switched the deaerator steam source from auxiliary steam to turbine stage 4 extraction steam. This manual switching of the deaerator steam source poses a significant safety risk to the unit startup process. This can lead to risks such as deaerator pressure fluctuations, deaerator water level fluctuations, improper switching timing, misjudgment of manual operation parameters, and insufficient emergency response capabilities. If the deaerator steam source is manually switched by the operator, if the fourth-stage steam extraction valve of the steam turbine opens too quickly or the auxiliary steam valve closes too quickly, there will be a risk of deaerator pressure fluctuations; a sudden increase in deaerator pressure may trigger the deaerator safety valve to operate, resulting in working fluid loss and equipment damage; a sudden drop in deaerator pressure will cause vaporization at the feed water pump inlet, causing pump unit vibration and even equipment damage; during the manual switching process, if the deaerator pressure changes significantly, it will cause the saturation temperature in the deaerator to change, and the enthalpy value of the condensed water will change, affecting the stability of the water level regulation system, causing deaerator water level fluctuations; if the deaerator water level is too high, it may cause water hammer, damaging pipelines and equipment; if the deaerator water level is too low, it may trigger low water level protection; during the manual switching process of the operator, the fourth-stage steam extraction temperature of the steam turbine is usually higher than the auxiliary steam temperature. If the pipe is not fully warmed up before switching or the switching speed is too fast, the deaerator will be If the thermal stress of the deaerator and pipeline is too large, it will cause uneven expansion of the pipeline, causing vibration or cracks, and thermal deformation of the internal components of the deaerator, which will affect the service life; during the manual switching process, if the fourth-stage extraction pressure of the steam turbine has not reached a sufficient level, premature switching will cause steam to flow back into the turbine extraction pipeline, causing an abnormal increase in the axial thrust of the turbine, threatening the safety of the unit, water hammer in the extraction pipeline, and damage to valves and pipelines; if the operator is inexperienced or unskilled in operation during the manual switching process, it may cause parameter misjudgment, resulting in a prolonged switching process, increased unit energy consumption, parameter fluctuations beyond the safe range, triggering protection actions and other risks; if the operator encounters abnormal operating conditions such as sudden changes in deaerator pressure or deaerator water level during the manual switching process, the operator's manual operation response speed will be slower than the automatic control, which will lead to the expansion of the fault, damage to equipment, and affect the safety of the unit operation. Summary of the Invention

[0003] In view of this, the present invention provides a method and system for automatically switching the deaerator steam source during the unit startup process, so as to solve the problems of deaerator pressure fluctuation, deaerator water level fluctuation, improper switching timing, misjudgment of manual operation parameters, insufficient emergency handling capabilities, etc. caused by the operator manually switching the unit deaerator steam source from auxiliary steam to turbine stage four extraction steam.

[0004] In a first aspect, the present invention provides a method for automatically switching a deaerator steam source during unit startup, the method comprising:

[0005] Automatically open the drain valve in front of the steam turbine's fourth-stage steam extraction electric valve, the drain valve behind the steam turbine's fourth-stage steam extraction check valve, and the drain valve behind the steam turbine's fourth-stage steam extraction electric valve to start the drain function of the fourth-stage steam extraction pipeline;

[0006] Automatically open the first steam turbine's fourth-stage extraction steam check valve and the second steam turbine's fourth-stage extraction steam check valve;

[0007] After the first steam turbine's fourth-stage steam extraction check valve and the second steam turbine's fourth-stage steam extraction check valve are fully opened, the fourth-stage steam extraction electric door of the steam turbine is automatically opened to complete the fourth-stage steam extraction pipeline heating;

[0008] After the switching conditions of the deaerator steam source are met, the four-stage steam extraction electric door of the steam turbine is fully opened according to the preset control strategy;

[0009] After the four-stage steam extraction electric door of the steam turbine is fully opened, the four-stage steam extraction to deaerator electric door is automatically opened, and after the four-stage steam extraction to deaerator electric door is fully opened, the auxiliary steam header to deaerator regulating door is closed at a first preset rate;

[0010] After the regulating door from the auxiliary steam header to the deaerator is fully closed, the electric door from the auxiliary steam header to the deaerator is automatically closed.

[0011] The present invention provides a method for controlling the automatic switching of the deaerator steam source during the unit startup process. Through logic design, during the high-speed warm-up stage of the steam turbine, when the drain electric door and manual door related to the steam source from the turbine four-stage extraction to the deaerator meet the drain conditions, the deaerator steam source automatic switching logic can be activated. The one-button start-up deaerator steam source automatic switching logic includes the main steam turbine four-stage extraction steam to deaerator pipeline warm-up logic and the auxiliary steam switching to steam turbine extraction steam automatic switching logic. During the steam turbine four-stage extraction steam to deaerator pipe warm-up process, after the steam parameters of the steam turbine four-stage extraction steam to the deaerator reach the standard, it can be confirmed that the steam turbine four-stage extraction steam to deaerator pipe warm-up is completed. After the steam turbine four-stage extraction steam to deaerator pipe warm-up is completed, the four-stage extraction steam electric door is slowly opened to fully open, the four-stage extraction steam to deaerator electric door is fully opened, the auxiliary steam to deaerator regulating valve is slowly closed, and then the auxiliary steam to deaerator electric door is fully closed. At this point, the deaerator steam source is switched from auxiliary steam to the turbine four-stage extraction steam. This application improves the automation level of the unit, ensures safe operation of the unit during the startup phase, and has achieved good results in actual production applications.

[0012] In an optional embodiment, the fourth-stage steam extraction electric door of the steam turbine is automatically opened to complete the fourth-stage steam extraction pipe heating, including:

[0013] The opening of the steam turbine's fourth-stage steam extraction electric door is set to a first opening to perform preliminary air intake into the fourth-stage steam extraction pipeline;

[0014] After the air intake time of the fourth-stage steam extraction pipeline reaches a first preset time, the opening of the fourth-stage steam extraction electric door of the steam turbine is set to a second opening, and the fourth-stage steam extraction pipeline is warmed up at the second opening;

[0015] After the pipe warming time reaches the second preset time, the opening of the fourth-stage steam extraction electric door of the steam turbine is set to the third opening;

[0016] Determine whether the fourth-stage steam extraction electric door opening feedback of the steam turbine is greater than or equal to the third opening, whether the fourth-stage steam extraction pressure feedback is greater than a first pressure threshold, and whether the fourth-stage steam extraction pipeline temperature feedback is greater than a first temperature threshold;

[0017] If the fourth-stage steam extraction electric door opening feedback of the steam turbine is greater than or equal to the third opening, the fourth-stage steam extraction pressure feedback is greater than the first pressure threshold, and the fourth-stage steam extraction pipeline temperature feedback is greater than the first temperature threshold, it is determined that the fourth-stage steam extraction pipeline heating is completed.

[0018] In an optional embodiment, the switching conditions of the deaerator steam source include:

[0019] The turbine speed is greater than the preset speed and the drain valve in front of the steam turbine fourth-stage extraction electric valve, the drain valve after the steam turbine fourth-stage extraction check valve, and the drain valve after the steam turbine fourth-stage extraction electric valve are fully open.

[0020] In an optional embodiment, fully opening the four-stage steam extraction electric door of the steam turbine according to a preset control strategy includes:

[0021] Setting the instruction of the fourth-stage steam extraction electric door of the steam turbine to increase by the first opening;

[0022] Determining whether the opening feedback of the fourth-stage steam extraction electric door of the steam turbine is greater than or equal to the fourth opening;

[0023] If the opening degree feedback of the fourth-stage steam extraction electric door of the steam turbine is greater than or equal to the fourth opening degree, suspending the opening degree instruction;

[0024] After the pause time of the opening instruction reaches the third preset time, the step of setting the instruction of the steam turbine fourth-stage steam extraction electric door to increase by the first opening is returned to, until the steam turbine fourth-stage steam extraction electric door is fully opened.

[0025] In an optional embodiment, closing the regulating gate from the auxiliary steam header to the deaerator at a first preset rate includes:

[0026] The auxiliary steam header to deaerator control door command is changed from 100% to 0% at a first preset rate.

[0027] In an optional implementation, the first preset rate is 1% / s.

[0028] In an optional embodiment, the preset rotation speed is 2700 rpm.

[0029] In a second aspect, the present invention provides a deaerator steam source automatic switching control system during unit startup, the system comprising:

[0030] The drain function start module is used to automatically open the drain valve in front of the steam turbine's fourth-stage steam extraction electric valve, the drain valve after the steam turbine's fourth-stage steam extraction check valve, and the drain valve after the steam turbine's fourth-stage steam extraction electric valve, thereby starting the drain function of the fourth-stage steam extraction pipeline;

[0031] The first valve processing module is used to automatically open the fourth-stage steam extraction check valve of the first steam turbine and the fourth-stage steam extraction check valve of the second steam turbine;

[0032] The pipe heating function starting module is used to automatically open the fourth-stage steam extraction electric door of the steam turbine after the fourth-stage steam extraction check valve of the first steam turbine and the fourth-stage steam extraction check valve of the second steam turbine are fully opened to complete the pipe heating of the fourth-stage steam extraction pipeline;

[0033] The steam source pipeline switching module is used to fully open the four-stage steam extraction electric door of the steam turbine according to the preset control strategy after the switching conditions of the deaerator steam source are met;

[0034] a second valve processing module, configured to automatically open the fourth-stage steam extraction to deaerator electric door after the fourth-stage steam extraction electric door of the steam turbine is fully opened, and to close the auxiliary steam header to deaerator regulating door at a first preset rate after the fourth-stage steam extraction to deaerator electric door is fully opened;

[0035] The third valve processing module is used for the warm pipe starting module, and is used to automatically close the electric door from the auxiliary steam header to the deaerator after the regulating door from the auxiliary steam header to the deaerator is fully closed.

[0036] The present invention provides a deaerator steam source automatic switching control system during the unit startup process. Through logic design, during the high-speed warm-up stage of the steam turbine, when the drain electric door and manual door related to the steam source of the steam turbine four-stage extraction to the deaerator meet the drain conditions, the deaerator steam source automatic switching logic can be started. The one-button start-up deaerator steam source automatic switching logic includes the main steam turbine four-stage extraction steam to deaerator pipeline warm-up logic and the auxiliary steam switching to steam turbine extraction steam automatic switching logic. During the steam turbine four-stage extraction steam to deaerator pipe warm-up process, after the steam parameters of the steam turbine four-stage extraction steam to the deaerator reach the standard, it can be confirmed that the steam turbine four-stage extraction steam to the deaerator pipe warm-up is completed. After the steam turbine four-stage extraction steam to the deaerator pipe warm-up is completed, the four-stage extraction steam electric door is slowly opened to fully open, the four-stage extraction steam to deaerator electric door is fully opened, the auxiliary steam to deaerator regulating valve is slowly closed, and then the auxiliary steam to deaerator electric door is fully closed. At this point, the deaerator steam source is switched from auxiliary steam to the steam turbine four-stage extraction steam. This application improves the automation level of the unit, ensures safe operation of the unit during the startup phase, and has achieved good results in actual production applications.

[0037] In a third aspect, the present invention provides a computer device comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the computer instructions to execute the method for automatic switching control of the deaerator steam source during the unit startup process of the above-mentioned first aspect or any corresponding embodiment thereof.

[0038] In a fourth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute the method for automatically switching the deaerator steam source during the unit startup process of the above-mentioned first aspect or any corresponding embodiment thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0040] Figure 1 1 is a flow chart of a method for automatically switching a deaerator steam source during unit startup according to an embodiment of the present invention;

[0041] Figure 2 This is a layout diagram of the steam source equipment of the deaerator of the unit according to an embodiment of the present invention;

[0042] Figure 3 This is a logic diagram of the pipe warming from the fourth extraction line of the steam turbine to the deaerator of the unit according to an embodiment of the present invention;

[0043] Figure 4 This is a logic diagram of the deaerator of the unit switching from auxiliary steam to fourth-stage extraction steam according to an embodiment of the present invention;

[0044] Figure 5 This is a structural block diagram of a deaerator steam source automatic switching control system during unit startup according to an embodiment of the present invention;

[0045] Figure 6 Schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0046] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0047] As an important auxiliary machine of thermal power units, the deaerator plays a vital role in the startup and operation of the units. During the startup phase, the deaerator heats the feed water using auxiliary steam and other heat sources to increase the feed water temperature and reduce the thermal stress caused by temperature differences during the startup process, which helps to speed up the startup of the unit and protect the equipment from damage caused by excessive thermal stress. Establishing the water level: The deaerator needs to adjust the water level to a normal range to provide a stable water source for the boiler. By feeding water into the deaerator and controlling the water flow and water level, it ensures that the boiler has sufficient feed water supply when the unit starts, avoiding problems such as feed water pump vaporization or boiler water shortage due to low water level. Deoxygenation preparation: Before the unit starts, the deaerator begins the deoxygenation operation, gradually removing gases such as dissolved oxygen in the water, preparing to supply qualified deoxygenated water to the boiler after the unit starts, and preventing oxygen from corroding the equipment during the startup process. During unit operation, the deaerator continuously removes dissolved oxygen and other gases from the feedwater, maintaining an extremely low oxygen content. This protects the entire thermal system's equipment, prevents oxygen corrosion, and ensures safe and reliable unit operation. Feedwater heating utilizes steam extraction from the turbine to heat the feedwater to its saturation temperature at the appropriate pressure, thereby increasing its enthalpy. This helps improve the unit's thermal efficiency, reduce fuel consumption, and lower power generation costs. Water level regulation: The deaerator maintains water level fluctuations within a normal range through an automatic water level control system. When the unit load fluctuates, the deaerator automatically adjusts the water inlet and outlet to ensure a stable deaerator water level, providing a steady feedwater flow to the boiler. This prevents excessively high water levels from causing water shock, or excessively low water levels from affecting the normal operation of the feedwater pump. Buffering and pressure stabilization: the deaerator can buffer the pressure fluctuations of the feed water system to a certain extent. When the feed water pressure changes due to sudden changes in turbine load or feed water pump failure, the deaerator can absorb part of the pressure fluctuations through its own volume and water level changes, maintain the relative stability of the feed water system, and reduce the impact on equipment such as boilers.

[0048] During the unit startup phase, the deaerator's steam source cannot be obtained from turbine extraction steam because the turbine itself lacks a heat source. Therefore, the deaerator's steam source is derived from the unit's auxiliary steam. Once the unit is operating normally, turbine extraction steam can provide steam for the deaerator. Therefore, during normal operation, the deaerator's steam source must be switched from auxiliary steam to turbine extraction steam. During the unit startup phase, the deaerator's steam source is derived from the unit's auxiliary steam. In the initial stages of startup, the turbine has not yet reached normal operating conditions, and there is insufficient extraction steam to meet the deaerator's heating needs. At this time, the auxiliary steam serves as the primary steam source, providing heat to the deaerator, rapidly raising the water temperature within the deaerator to the required deaeration temperature. This also establishes the deaerator's operating pressure, paving the way for unit startup. During normal operation, the deaerator's steam source is derived from the fourth extraction steam source. The fourth extraction steam has the appropriate pressure and temperature parameters to meet the deaerator's water heating requirements and achieve effective deaeration. At the same time, the use of four-extraction steam as the steam source for the deaerator complies with the principle of heat recovery cycle, which can improve the thermal economy of the unit, reduce the loss of cold source, and make more full use of the thermal energy of the steam.

[0049] Currently, power generation companies generally rely on operators to manually switch the deaerator steam source. During manual switching, it is difficult to accurately control the parameters of the deaerator steam source during the switching process. Manual switching is also prone to misoperation, posing safety risks to unit operation. Therefore, this application provides a method for automatically switching the deaerator steam source during unit startup. The method automatically achieves steam source switching by logically controlling the auxiliary steam electric gate, auxiliary steam regulating valve, steam turbine fourth-stage extraction electric gate, fourth-stage extraction check valve, and other equipment through the control system.

[0050] According to an embodiment of the present invention, an embodiment of a method for automatically switching the steam source of a deaerator during the startup of a unit is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0051] In this embodiment, a method for automatically switching the steam source of a deaerator during the unit startup process is provided. Figure 1 FIG. 1 is a flow chart of a method for automatically switching a deaerator steam source during unit startup according to an embodiment of the present invention. Figure 1 As shown, the process includes the following steps:

[0052] Step S1, automatically open the drain valve 3 in front of the steam turbine fourth-stage steam extraction electric valve, the drain valve 8 after the steam turbine fourth-stage steam extraction check valve, and the drain valve 5 after the steam turbine fourth-stage steam extraction electric valve to start the drain function of the fourth-stage steam extraction pipeline.

[0053] Specifically, the layout diagram of the deaerator steam source equipment is as follows: Figure 2As shown in the figure, the main equipment of the unit's deaerator steam source system includes auxiliary steam header to deaerator electric gate 1, auxiliary steam header to deaerator regulating gate 2, turbine fourth-stage extraction steam electric gate pre-drain gate 3, turbine fourth-stage extraction steam electric gate 4, turbine fourth-stage extraction steam electric gate post-drain gate 5, first turbine fourth-stage extraction steam check valve 6, second turbine fourth-stage extraction steam check valve 7, turbine fourth-stage extraction steam post-drain gate 8, turbine fourth-stage extraction steam to deaerator electric gate 9, deaerator pre-drain gate 10, first deaerator steam inlet electric gate 11, and second deaerator steam inlet electric gate 12. The one-button start deaerator steam source automatic switching control system includes turbine fourth extraction steam source to deaerator pipeline heating and automatic switching of auxiliary steam to turbine fourth extraction steam source.

[0054] In an embodiment of the present invention, the warming up of the four-stage steam extraction to deaerator pipeline needs to be completed before the steam source is switched, and the first step of the warming up is to realize the drainage function of the pipeline. The specific implementation process of the drainage function is as follows: the drainage gate 3 in front of the four-stage steam extraction electric gate of the steam turbine, the drainage gate 8 after the four-stage steam extraction check valve of the steam turbine, and the drainage gate 5 after the four-stage steam extraction electric gate of the steam turbine realize the drainage function of the pipeline.

[0055] Step S2, automatically opening the first steam turbine fourth-stage extraction steam check valve 6 and the second steam turbine fourth-stage extraction steam check valve 7.

[0056] Specifically, the second step of warming up the pipes is as follows: after the drain function is realized, the fourth-stage steam extraction check valve 6 of the first steam turbine and the fourth-stage steam extraction check valve 7 of the second steam turbine are automatically opened.

[0057] Step S3: After the first turbine's fourth-stage steam extraction check valve 6 and the second turbine's fourth-stage steam extraction check valve 7 are fully opened, the turbine's fourth-stage steam extraction electric door 4 is automatically opened to complete the fourth-stage steam extraction pipeline heating.

[0058] Specifically, the third step of pipe warming is as follows: After the fourth-stage extraction steam check valve is fully opened, the fourth-stage extraction steam electric door 4 of the steam turbine is automatically opened. During the process of automatically opening the fourth-stage extraction steam electric door 4 of the steam turbine, the operating experience of the operator is implemented in the control logic. To prevent pipeline oscillation during the pipe warming process, the following operations are taken:

[0059] Step S31 , setting the opening of the fourth-stage steam extraction electric door 4 of the steam turbine to a first opening, and performing preliminary air intake into the fourth-stage steam extraction pipeline.

[0060] Step S32 , after the air intake time of the fourth-stage steam extraction pipeline reaches a first preset time, the opening of the fourth-stage steam extraction electric door 4 of the steam turbine is set to a second opening, and the fourth-stage steam extraction pipeline is warmed at the second opening.

[0061] Step S33: After the pipe warming time reaches the second preset time, the opening of the turbine fourth-stage steam extraction electric door 4 is set to the third opening.

[0062] Step S34 , determining whether the opening feedback of the fourth-stage steam extraction electric door 4 of the steam turbine is greater than or equal to the third opening, whether the fourth-stage steam extraction pressure feedback is greater than the first pressure threshold, and whether the fourth-stage steam extraction pipeline temperature feedback is greater than the first temperature threshold.

[0063] In step S35, if the opening feedback of the fourth-stage steam extraction electric door 4 of the steam turbine is greater than or equal to the third opening, the fourth-stage steam extraction pressure feedback is greater than the first pressure threshold, and the fourth-stage steam extraction pipeline temperature feedback is greater than the first temperature threshold, it is determined that the fourth-stage steam extraction pipeline warming is completed.

[0064] In an embodiment of the present invention, the first opening is 5%, the second opening is 10%, and the third opening is 30%. The first preset time is 5 minutes, and the second preset time is 20 minutes. The first pressure threshold is 0.147 MPa, and the first temperature threshold is 180°C. In actual operation, first preset the opening of the fourth-stage steam extraction electric door to 5% to achieve initial steam intake into the pipeline. After 5 minutes of initial steam intake, set the electric door to 10% opening. After 20 minutes of pipe heating, set the opening to 30% to continue pipe heating. When the pipe is heated to the pressure of the fourth-stage steam extraction pipeline > 0.147 MPa and the temperature of the fourth-stage steam extraction pipeline > 180°C, the logic can automatically determine that the heating of the fourth-stage steam extraction pipeline is completed.

[0065] Step S4: After the switching conditions of the deaerator steam source are met, the steam turbine four-stage steam extraction electric door 4 is fully opened according to the preset control strategy.

[0066] Specifically, during the startup process, the switching conditions for the deaerator steam source to switch from auxiliary steam to the turbine's fourth-stage extraction steam are: 1) the turbine is in the high-speed warm-up stage, that is, the turbine speed is greater than 2700rpm, and 2) the deaerator steam source is switched to the fourth-stage extraction-related drain manual door and is open; when the switching conditions are met, the start command can be triggered by the handheld operator button to automatically realize the deaerator steam source switching function. After the turbine's fourth-stage extraction steam pipeline is warmed up, the deaerator steam source switching can be started. Since the turbine's fourth-stage extraction steam electric door 4 is open at 30% after the warm-up is completed, the turbine's fourth-stage extraction steam electric door 4 should be fully opened in advance when switching. Considering that the turbine's fourth-stage extraction steam electric door 4 opens from 30% to 100% fully, a large amount of steam will instantly enter the pipeline, causing pipeline oscillation. Therefore, based on the operating experience of the operating personnel, the following operations are taken:

[0067] Step S41 , setting the instruction of the turbine fourth-stage steam extraction electric door 4 to increase by a first opening degree.

[0068] Step S42: determine whether the opening feedback of the fourth-stage steam extraction electric door 4 of the steam turbine is greater than or equal to the fourth opening.

[0069] Step S43: If the opening degree feedback of the turbine fourth-stage extraction electric door 4 is greater than or equal to the fourth opening degree, suspend the opening degree instruction.

[0070] Step S44, after the pause time of the opening instruction reaches the third preset time, return to the step of setting the instruction of the steam turbine fourth stage extraction steam electric door 4 to increase by the first opening until the steam turbine fourth stage extraction steam electric door 4 is fully opened.

[0071] In this embodiment of the present invention, the fourth opening degree is 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, and 100%. The third preset time is 10 seconds. In actual operation, the steam turbine fourth stage extraction steam electric door 4 starts at 30%, and after each 5% increase in opening, the opening command is paused for 10 seconds, and then the opening is increased by another 5% until the steam turbine fourth stage extraction steam electric door 4 is fully opened.

[0072] Step S5: After the turbine stage 4 steam extraction electric door 4 is fully opened, the turbine stage 4 steam extraction to deaerator electric door 9 is automatically opened; after the turbine stage 4 steam extraction to deaerator electric door 9 is fully opened, the auxiliary steam header to deaerator regulating door 2 is closed at a first preset rate.

[0073] Specifically, after the turbine's fourth-stage extraction electric door 4 is fully opened, the control logic triggers a command to fully open the turbine's fourth-stage extraction-to-deaerator electric door 9. After receiving feedback that the turbine's fourth-stage extraction-to-deaerator electric door 9 is fully open, the control logic slowly closes the auxiliary steam header-to-deaerator regulating door 2. Based on operational experience, the command to adjust the auxiliary steam header-to-deaerator regulating door 2 is changed from 100% to 0% at a first preset rate, which is 1% / s, until the auxiliary steam header-to-deaerator regulating door 2 is fully closed.

[0074] Step S6: After the auxiliary steam header to deaerator regulating door 2 is fully closed, the auxiliary steam header to deaerator electric door 1 is automatically closed.

[0075] Specifically, after the control logic receives the fully closed instruction for the auxiliary steam manifold to deaerator regulating door 2, the auxiliary steam manifold to deaerator electric door 1 fully close instruction is issued. After the auxiliary steam manifold to deaerator electric door 1 is fully closed, the control logic determines that the deaerator steam source has been switched from auxiliary steam to the fourth-stage steam extraction of the steam turbine, and the switching completion status is displayed on the operation screen.

[0076] The present invention provides a method for controlling the automatic switching of the deaerator steam source during the unit startup process. Through logic design, during the high-speed warm-up stage of the steam turbine, when the drain electric door and manual door related to the steam source from the turbine four-stage extraction to the deaerator meet the drain conditions, the deaerator steam source automatic switching logic can be activated. The one-button start-up deaerator steam source automatic switching logic includes the main steam turbine four-stage extraction steam to deaerator pipeline warm-up logic and the auxiliary steam switching to steam turbine extraction steam automatic switching logic. During the steam turbine four-stage extraction steam to deaerator pipe warm-up process, after the steam parameters of the steam turbine four-stage extraction steam to the deaerator reach the standard, it can be confirmed that the steam turbine four-stage extraction steam to deaerator pipe warm-up is completed. After the steam turbine four-stage extraction steam to deaerator pipe warm-up is completed, the four-stage extraction steam electric door is slowly opened to fully open, the four-stage extraction steam to deaerator electric door is fully opened, the auxiliary steam to deaerator regulating valve is slowly closed, and then the auxiliary steam to deaerator electric door is fully closed. At this point, the deaerator steam source is switched from auxiliary steam to the turbine four-stage extraction steam. This application improves the automation level of the unit, ensures safe operation of the unit during the startup phase, and has achieved good results in actual production applications.

[0077] In a specific embodiment, Figure 3This is the pipe warming logic for the unit's steam turbine's fourth-stage extraction to deaerator pipeline, including: 1—STEP step control function block, which implements the pipe warming sequence for the steam turbine's fourth-stage extraction to deaerator pipeline; 2—D / MA hand operator control block, which implements one-button start of the steam turbine's fourth-stage extraction to deaerator pipeline warming; 3—D / MA hand operator control block, which implements the pause function during the pipe warming process of the steam turbine's fourth-stage extraction to deaerator pipeline; 4—D / MA hand operator control block, which manually confirms that the deaerator steam source has been switched to the fourth-stage extraction-related drain manual door and that it has been opened; 5 and 6—PAI analog inputs, which receive steam turbine speed signals and HLALM high and low limit alarms, determine that the steam turbine speed is greater than 2700rpm and the steam turbine enters the high-speed warming stage; 7—AND two-signal phase AND operation 8—DO switch output, to trigger the opening of the drain valve in front of the fourth-stage steam extraction electric valve, the drain valve after the fourth-stage steam extraction check valve, and the drain valve after the fourth-stage steam extraction electric valve; 9, 10, 11—PDI switch input, respectively, are the feedback signals for judging whether the drain valve in front of the fourth-stage steam extraction electric valve, the drain valve after the fourth-stage steam extraction check valve, and the drain valve after the fourth-stage steam extraction electric valve are fully opened; 12—AND three-signal phase AND algorithm block, to judge whether the three drain valves are fully opened; 13—TIMER timer algorithm block, to realize the logic judgment of delaying 300s after the three drain valves are fully opened. 14—PDO switch output, triggering the opening of the first turbine fourth stage extraction steam check valve and the second turbine fourth stage extraction steam check valve command signal; 15, 16—PDI switch input, respectively, judging whether the first turbine fourth stage extraction steam check valve and the second turbine fourth stage extraction steam check valve are fully opened feedback signal; 17—AND two-signal AND algorithm block, judging whether the first turbine fourth stage extraction steam check valve and the second turbine fourth stage extraction steam check valve are fully opened; 18, 19—KBML analog setting function block, after receiving the step command signal, sets the turbine fourth stage extraction steam electric door command to 5%, AO analog output, sends the 5% opening command to the turbine fourth stage extraction steam electric door; 20, 25, 30—PAI analog input, receiving Receive the opening feedback of the fourth-stage steam extraction electric door of the steam turbine; 21, 22—HLALM high and low limit alarms, determine the opening feedback of the fourth-stage steam extraction electric door of the steam turbine ≥5%, and the TIMER timer algorithm block, realize the pipe heating for 300 seconds when the fourth-stage steam extraction electric door of the steam turbine is opened at 5%; 23, 24—KBML analog setting function blocks, after receiving the step command signal, set the fourth-stage steam extraction electric door command to 10%, AO analog output, and send the 10% opening command to the fourth-stage steam extraction electric door of the steam turbine; 26, 27—HLALM high and low limit alarms, determine the opening feedback of the fourth-stage steam extraction electric door of the steam turbine ≥10%, and the TIMER timer algorithm block, realize the pipe heating for 1200 seconds when the fourth-stage steam extraction electric door of the steam turbine is opened at 10%;28, 29—KBML analog setting function block, after receiving the step command signal, sets the turbine fourth-stage extraction electric door command to 30%, AO analog output, and sends the 30% opening command to the turbine fourth-stage extraction electric door; 31—HLALM high and low limit alarm, judges the turbine fourth-stage extraction electric door opening feedback ≥30%; 32—PAI analog input, receives the fourth-stage extraction pressure feedback; 33—HLALM high and low limit alarm, judges the fourth-stage extraction pressure ≥0.147MPa; 34—PAI analog input, receives the fourth-stage extraction temperature feedback; 35—HLALM high and low limit alarm, judges the fourth-stage extraction temperature ≥180℃; 36—AND three-signal phase and algorithm block, judges the fourth-stage extraction electric door feedback, fourth-stage extraction pressure, and fourth-stage extraction temperature Meet the parameters for pipe warming completion; 37—D / MA handheld operator control block, manual trigger button, realizes the reset function of the pipe warming sequence of the four-stage steam extraction to deaerator pipe; 38—NAO network analog output block, realizes the step display function of the pipe warming process of the four-stage steam extraction to deaerator pipe; 39—NAO network analog output block, realizes the pipe warming time display function of the four-stage steam extraction to deaerator pipe; 40—NAO network analog output block, realizes the remaining time display function of the pipe warming process of the four-stage steam extraction to deaerator pipe; 41—NDO network switch output block, realizes the step fault display function of the pipe warming process of the four-stage steam extraction to deaerator pipe; 42—NDO network switch output block, realizes the pipe warming completion display function of the four-stage steam extraction to deaerator pipe.

[0078] In a specific embodiment, Figure 4The logic for switching the deaerator from auxiliary steam to four-stage extraction steam is shown in Figure 1. 1—STEP step control function block, in which the steam source switching function of the turbine four-stage extraction steam to the deaerator is realized; 2—D / MA hand operator control block, which realizes one-button start of the steam source switching of the turbine four-stage extraction steam to the deaerator; 3—D / MA hand operator control block, which realizes the pause function during the switching process of the turbine four-stage extraction steam to the deaerator; 4—PDI switch input module, which determines that the warm-up of the turbine four-stage extraction steam to the deaerator pipe is completed and allows the steam source switching step of the turbine four-stage extraction steam to the deaerator; 5—PDO switch output module, which realizes triggering the full opening of the turbine four-stage extraction steam 6—PDI switch input module, receives feedback on the full opening of the turbine's fourth-stage extraction electric door; 7—PDO switch output module, triggers the full opening of the turbine's fourth-stage extraction to deaerator electric door command; 8—PDI switch input module, receives feedback on the full opening of the turbine's fourth-stage extraction to deaerator electric door; 9, 10—KBML analog setting function blocks, after receiving the step command signal, set the auxiliary steam to deaerator throttle command to 0%, and the LEADLAG lead-lag function block sets the lag time to 100s, that is, the auxiliary steam to deaerator throttle command is changed from 100% to 0% within 100s; 11 —PAO analog output module, issues an automatic closure of the auxiliary steam to deaerator regulating valve; 12, 13—PAI analog input modules, receive feedback from the auxiliary steam header to the deaerator regulating valve, HLALM high and low limit alarm, and judge that the feedback from the auxiliary steam header to the deaerator regulating valve is less than 3%; 14—PDO switching output module, triggers the command to fully close the auxiliary steam header to the deaerator electric door; 15—PDI switching input module, receives feedback from the auxiliary steam header to the deaerator electric door fully closed; 16—NAO network analog output block, realizes the step display function in the process of switching the steam source from the fourth stage extraction steam of the steam turbine to the deaerator; 17—NAO The network analog output block realizes the switching time display function during the switching process of the steam source from the fourth stage steam extraction of the steam turbine to the deaerator; 18—NAO network analog output block realizes the remaining time display function during the switching process of the steam source from the fourth stage steam extraction of the steam turbine to the deaerator; 19—NDO network switch output block realizes the step fault display function during the switching process of the steam source from the fourth stage steam extraction of the steam turbine to the deaerator; 20—NDO network switch output block realizes the completion display function of the switching process of the steam source from the fourth stage steam extraction of the steam turbine to the deaerator; 21—D / MA handheld operator control block, manual trigger button, realizes the step reset function of the switching process of the steam source from the fourth stage steam extraction of the steam turbine to the deaerator.

[0079] This embodiment also provides a control system for automatically switching the deaerator steam source during unit startup. This system is used to implement the above-mentioned embodiments and preferred implementations, and details already described will not be repeated. As used below, the term "module" may refer to a combination of software and / or hardware that implements a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, implementation using hardware, or a combination of software and hardware, is also possible and contemplated.

[0080] This embodiment provides a deaerator steam source automatic switching control system during the unit startup process, such as Figure 5 Shown, including:

[0081] The drain function starting module 51 is used to automatically open the drain valve in front of the fourth-stage steam extraction electric valve, the drain valve after the fourth-stage steam extraction check valve, and the drain valve after the fourth-stage steam extraction electric valve of the steam turbine to start the drain function of the fourth-stage steam extraction pipeline.

[0082] The first valve processing module 52 is used for automatically opening the fourth-stage steam extraction check valve of the first steam turbine and the fourth-stage steam extraction check valve of the second steam turbine.

[0083] The pipe heating function starting module 53 is used to automatically open the steam turbine's fourth-stage steam extraction electric door after the first steam turbine's fourth-stage steam extraction check valve and the second steam turbine's fourth-stage steam extraction check valve are fully opened to complete the fourth-stage steam extraction pipe heating.

[0084] The steam source pipeline switching module 54 is used to fully open the steam turbine's four-stage steam extraction electric door according to a preset control strategy after the switching conditions for the deaerator steam source are met.

[0085] The second valve processing module 55 is used to automatically open the fourth-stage steam extraction to deaerator electric door after the fourth-stage steam extraction electric door of the steam turbine is fully opened, and close the auxiliary steam header to deaerator regulating door at a first preset rate after the fourth-stage steam extraction to deaerator electric door is fully opened.

[0086] The third valve processing module 56 is used for the pipe warming start module, and is used to automatically close the electric door from the auxiliary steam header to the deaerator after the regulating door from the auxiliary steam header to the deaerator is fully closed.

[0087] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0088] The deaerator steam source automatic switching control system during the unit startup process in this embodiment is presented in the form of function blocks. The function blocks here refer to software modules with input and output interfaces that can perform specific functions. By connecting the function blocks, a complex control system can be constructed to realize various control algorithms and logical functions.

[0089] This application provides a fully automatic, non-disruptive switching control system. This control strategy includes a process for warming up the steam turbine-to-deaerator pipeline. After warming up, the auxiliary steam automatically switches to the turbine's fourth-stage extraction process. The control logic automatically implements valve operation, parameter monitoring, and parameter adjustment, avoiding equipment misoperation and parameter misjudgment caused by manual switching by operators, thereby improving the safety and stability of the unit during startup. Through logical design, this application automatically implements complex operation processes without the need for manual intervention, shortening the switching time to less than 10 minutes. The entire process is automatically operated, reducing the labor intensity of operators. Automatic switching avoids problems such as reduced deoxidation efficiency and deterioration of feedwater quality caused by delayed or improper manual operation, providing a reliable guarantee for the long-term stable operation of the unit. The control strategy design method of this application is easy to implement and has achieved good results in actual application. According to calculations, steam loss during the deaerator steam source switching process was reduced by approximately 1.5 tons / hour, and the unit startup time was shortened by 15 to 20 minutes. Based on five startups per year, the annual startup cost savings are approximately 300,000 yuan.

[0090] The embodiment of the present invention also provides a computer device having the above Figure 5 The figure shows the deaerator steam source automatic switching control system during the unit startup process.

[0091] See also Figure 6 , Figure 6 is a structural diagram of a computer device provided by an optional embodiment of the present invention, such as Figure 6 As shown, the computer device includes: one or more processors 10, memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components utilize different buses to communicate with each other and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in the memory or on the memory to display the graphical information of the GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Equally, multiple computer devices can be connected, and each device provides part of the necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 6 A processor 10 is taken as an example.

[0092] The processor 10 may be a central processing unit, a network processor, or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit, a programmable logic device, or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic, or any combination thereof.

[0093] The memory 20 stores instructions that can be executed by at least one processor 10, so that the at least one processor 10 executes the method shown in the above embodiment.

[0094] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and application programs required for at least one function; the data storage area may store data created based on the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely located relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0095] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid-state drive; the memory 20 may also include a combination of the above types of memory.

[0096] The computer device further includes a communication interface 30 for the computer device to communicate with other devices or a communication network.

[0097] The embodiment of the present invention also provides a computer-readable storage medium. The above-mentioned method according to the embodiment of the present invention can be implemented in hardware, firmware, or implemented as a computer code that can be recorded in a storage medium, or implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and downloaded through a network and will be stored in a local storage medium, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state drive, etc.; further, the storage medium can also include a combination of the above-mentioned types of memory. It can be understood that a computer, a processor, a microprocessor controller or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor or hardware, the method shown in the above embodiment is implemented.

[0098] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A method for automatically switching the steam source of a deaerator during the unit startup process, characterized in that: The method comprises: Automatically open the drain valve in front of the steam turbine's fourth-stage steam extraction electric valve, the drain valve behind the steam turbine's fourth-stage steam extraction check valve, and the drain valve behind the steam turbine's fourth-stage steam extraction electric valve to start the drain function of the fourth-stage steam extraction pipeline; Automatically open the first steam turbine's fourth-stage extraction steam check valve and the second steam turbine's fourth-stage extraction steam check valve; After the first steam turbine's fourth-stage steam extraction check valve and the second steam turbine's fourth-stage steam extraction check valve are fully opened, the fourth-stage steam extraction electric door of the steam turbine is automatically opened to complete the fourth-stage steam extraction pipeline heating; After the switching conditions of the deaerator steam source are met, the four-stage steam extraction electric door of the steam turbine is fully opened according to the preset control strategy; After the four-stage steam extraction electric door of the steam turbine is fully opened, the four-stage steam extraction to deaerator electric door is automatically opened, and after the four-stage steam extraction to deaerator electric door is fully opened, the auxiliary steam header to deaerator regulating door is closed at a first preset rate; After the regulating door from the auxiliary steam header to the deaerator is fully closed, the electric door from the auxiliary steam header to the deaerator is automatically closed.

2. The method for automatically switching the deaerator steam source during the unit startup process according to claim 1 is characterized in that: Automatically open the steam turbine's four-stage steam extraction electric door to complete the four-stage steam extraction pipe heating, including: The opening of the steam turbine's fourth-stage steam extraction electric door is set to a first opening to perform preliminary air intake into the fourth-stage steam extraction pipeline; After the air intake time of the fourth-stage steam extraction pipeline reaches a first preset time, the opening of the fourth-stage steam extraction electric door of the steam turbine is set to a second opening, and the fourth-stage steam extraction pipeline is warmed up at the second opening; After the pipe warming time reaches the second preset time, the opening of the fourth-stage steam extraction electric door of the steam turbine is set to the third opening; Determine whether the turbine fourth-stage extraction steam electric door opening feedback is greater than or equal to the third opening, whether the fourth-stage extraction steam pressure feedback is greater than a first pressure threshold, and whether the fourth-stage extraction steam pipeline temperature feedback is greater than a first temperature threshold; If the fourth-stage steam extraction electric door opening feedback of the steam turbine is greater than or equal to the third opening, the fourth-stage steam extraction pressure feedback is greater than the first pressure threshold, and the fourth-stage steam extraction pipeline temperature feedback is greater than the first temperature threshold, it is determined that the fourth-stage steam extraction pipeline heating is completed.

3. The method for automatically switching the steam source of the deaerator during the unit startup process according to claim 1 is characterized in that: The switching conditions of the deaerator steam source include: The turbine speed is greater than the preset speed and the drain valve in front of the steam turbine fourth-stage extraction electric valve, the drain valve after the steam turbine fourth-stage extraction check valve, and the drain valve after the steam turbine fourth-stage extraction electric valve are fully open.

4. The method for automatically switching the steam source of the deaerator during the unit startup process according to claim 2 is characterized in that: Fully opening the four-stage steam extraction electric door of the steam turbine according to the preset control strategy includes: Setting the instruction of the fourth-stage steam extraction electric door of the steam turbine to increase by the first opening; Determining whether the opening feedback of the fourth-stage steam extraction electric door of the steam turbine is greater than or equal to the fourth opening; If the opening degree feedback of the fourth-stage steam extraction electric door of the steam turbine is greater than or equal to the fourth opening degree, suspending the opening degree instruction; After the pause time of the opening instruction reaches the third preset time, the step of setting the instruction of the fourth-stage steam extraction electric door of the steam turbine to increase by the first opening is returned to, until the fourth-stage steam extraction electric door of the steam turbine is fully opened.

5. The method for automatically switching the steam source of the deaerator during the unit startup process according to claim 1 is characterized in that: Closing the regulating valve from the auxiliary steam header to the deaerator at a first preset rate includes: The auxiliary steam header to deaerator control door command is changed from 100% to 0% at a first preset rate.

6. The method for automatically switching the steam source of the deaerator during the unit startup process according to claim 5 is characterized in that: The first preset rate is 1% / s.

7. The method for automatically switching the steam source of a deaerator during the unit startup process according to claim 3 is characterized in that: The preset rotation speed is 2700 rpm.

8. A deaerator steam source automatic switching control system during unit startup, characterized in that: The system comprises: The drain function start module is used to automatically open the drain valve in front of the steam turbine's fourth-stage steam extraction electric valve, the drain valve after the steam turbine's fourth-stage steam extraction check valve, and the drain valve after the steam turbine's fourth-stage steam extraction electric valve, thereby starting the drain function of the fourth-stage steam extraction pipeline; The first valve processing module is used to automatically open the fourth-stage steam extraction check valve of the first steam turbine and the fourth-stage steam extraction check valve of the second steam turbine; The pipe heating function starting module is used to automatically open the fourth-stage steam extraction electric door of the steam turbine after the fourth-stage steam extraction check valve of the first steam turbine and the fourth-stage steam extraction check valve of the second steam turbine are fully opened to complete the pipe heating of the fourth-stage steam extraction pipeline; The steam source pipeline switching module is used to fully open the four-stage steam extraction electric door of the steam turbine according to the preset control strategy after the switching conditions of the deaerator steam source are met; a second valve processing module, configured to automatically open the fourth-stage steam extraction to deaerator electric door after the fourth-stage steam extraction electric door of the steam turbine is fully opened, and to close the auxiliary steam header to deaerator regulating door at a first preset rate after the fourth-stage steam extraction to deaerator electric door is fully opened; The third valve processing module is used for the warm pipe starting module, and is used to automatically close the electric door from the auxiliary steam header to the deaerator after the regulating door from the auxiliary steam header to the deaerator is fully closed.

9. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the deaerator steam source automatic switching control method during the unit startup process according to any one of claims 1 to 7 by executing the computer instructions.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the deaerator steam source automatic switching control method during the unit startup process according to any one of claims 1 to 7.

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