Thermal power unit and operation control method thereof

Abstract

The application relates to a thermal power unit and a running control method thereof. The thermal power unit comprises a boiler, a main steam turbine and a back pressure turbine, wherein: when at least one of the main steam turbine and the back pressure turbine is in a running state, the boiler continuously runs; a steam inlet end of the main steam turbine is connected with the boiler through a first branch of a first pipeline, a main steam valve is arranged on the first branch of the first pipeline, the main steam valve is opened when preset main steam turbine starting conditions are met, and the main steam valve is closed when preset main steam turbine stopping conditions are met; a steam inlet end of the back pressure turbine is connected with the boiler through a second branch of the first pipeline, a bypass valve is arranged on the second branch of the first pipeline, and the bypass valve is in an opened state when the main steam valve is in a closed state. The method can improve resource utilization.

Description

Technical Field

[0001] This application relates to the field of thermal power unit technology, and in particular to a thermal power unit and its operation control method. Background Technology

[0002] With the rapid development of my country's power industry, thermal power units, as an important component of the power system, have seen significant improvements in their technology and operating efficiency. Thermal power units convert the chemical energy of fuel into the thermal energy of steam, which in turn drives a steam turbine to rotate and power a generator, ultimately achieving a large-scale and stable supply of electricity.

[0003] The traditional startup process of thermal power units typically includes key stages such as feedwater pump turbine startup, boiler ignition, main turbine startup, generator grid connection, and gradual increase to the target load.

[0004] However, from the start-up of the feedwater pump turbine to the readiness of the main turbine, several hours of preparation time are typically required. During this extended preparation period, the steam generated by the boiler cannot be effectively utilized, resulting in wasted energy and a low overall resource utilization rate for the thermal power unit. Summary of the Invention

[0005] Therefore, it is necessary to provide a thermal power unit and its operation control method that can improve resource utilization in response to the above-mentioned technical problems.

[0006] In a first aspect, this application provides a thermal power unit, including a boiler, a main steam turbine, and a back-pressure steam turbine, wherein:

[0007] The boiler continues to operate while at least one of the main steam turbine and the back-pressure steam turbine is in operation;

[0008] The steam inlet of the main steam turbine is connected to the boiler through the first branch of the first pipeline. The first branch of the first pipeline is equipped with a main steam valve. The main steam valve opens when the preset main steam turbine start-up conditions are met and closes when the preset main steam turbine shutdown conditions are met.

[0009] The steam inlet of the back-pressure steam turbine is connected to the boiler through the second branch of the first pipeline. A bypass valve is installed on the second branch of the first pipeline. When the main steam valve is closed, the bypass valve is open.

[0010] In one embodiment, the thermal power unit further includes a first generator, with the main steam turbine connected to the first generator, which is configured to generate electricity under the drive of the main steam turbine.

[0011] In one embodiment, the thermal power unit further includes a second generator connected to a back-pressure steam turbine, the second generator being configured to generate electricity under the drive of the back-pressure steam turbine.

[0012] In one embodiment, the main steam turbine includes a high-pressure cylinder, and the steam inlet end of the main steam turbine includes the steam inlet end of the high-pressure cylinder; the steam inlet end of the high-pressure cylinder is connected to the boiler through a first branch of a first pipeline;

[0013] The first steam outlet of the high-pressure cylinder is connected to the second branch of the first pipeline through the second pipeline, and the bypass valve is located between the connection port of the second pipeline and the branch junction of the first pipeline.

[0014] In one embodiment, a first valve is provided on the second pipeline, and the first valve is in the open state when the bypass valve is in the closed state.

[0015] In one embodiment, the thermal power unit further includes a first high-pressure heater, a second high-pressure heater, and a third high-pressure heater; the main steam turbine also includes an intermediate-pressure cylinder;

[0016] The first high-pressure heater is connected to the first extraction end of the high-pressure cylinder via a third pipeline;

[0017] The second high-pressure heater is connected to the second extraction end of the high-pressure cylinder through the first branch of the fourth pipeline, and the second high-pressure heater is connected to the first extraction end of the back-pressure steam turbine through the second branch of the fourth pipeline.

[0018] The third high-pressure heater is connected to the first extraction end of the intermediate-pressure cylinder through the first branch of the fifth pipeline, and the third high-pressure heater is connected to the second extraction end of the back-pressure steam turbine through the second branch of the fifth pipeline.

[0019] In one embodiment, a second valve is provided on the first branch of the fourth pipeline, and a third valve is provided on the second branch of the fourth pipeline; a fourth valve is provided on the first branch of the fifth pipeline, and a fifth valve is provided on the second branch of the fifth pipeline.

[0020] When the bypass valve or the first valve is in the open state, the second valve is in the open state, the third valve is in the closed state, the fourth valve is in the closed state, and the fifth valve is in the open state.

[0021] When both the bypass valve and the first valve are closed, the second valve is closed, the third valve is open, the fourth valve is closed, and the fifth valve is open.

[0022] In one embodiment, the thermal power unit further includes a deaerator; the deaerator is connected to the second extraction end of the intermediate pressure cylinder via a first branch of the sixth pipeline; the deaerator is connected to the third extraction end of the back pressure turbine via a second branch of the sixth pipeline.

[0023] In one embodiment, a sixth valve is provided on the first branch of the sixth pipeline; a seventh valve is provided on the second branch of the sixth pipeline;

[0024] When the bypass valve or the first valve is in the open state, the sixth valve is in the closed state and the seventh valve is in the open state.

[0025] When both the bypass valve and the first valve are closed, the sixth valve is open and the seventh valve is closed.

[0026] Secondly, this application also provides a method for operating control of a thermal power unit, applied to the aforementioned thermal power unit; the method includes:

[0027] The main steam turbine is started when the preset main steam turbine start-up conditions are triggered;

[0028] When the preset main turbine shutdown conditions are triggered, the main turbine is shut down.

[0029] When the main steam turbine is shut down, the back-pressure steam turbine is controlled to continue running.

[0030] The boiler is controlled to operate continuously when at least one of the main steam turbine and the back-pressure steam turbine is in operation.

[0031] Thirdly, this application also provides a computer device for use in the aforementioned thermal power unit; the computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to perform the following steps:

[0032] The main steam turbine is started when the preset main steam turbine start-up conditions are triggered;

[0033] When the preset main turbine shutdown conditions are triggered, the main turbine is shut down.

[0034] When the main steam turbine is shut down, the back-pressure steam turbine is controlled to continue running.

[0035] The boiler is controlled to operate continuously when at least one of the main steam turbine and the back-pressure steam turbine is in operation.

[0036] Fourthly, this application also provides a computer-readable storage medium for use in the aforementioned thermal power unit; the computer-readable storage medium stores a computer program, which, when executed by a processor, performs the following steps:

[0037] The main steam turbine is started when the preset main steam turbine start-up conditions are triggered;

[0038] When the preset main turbine shutdown conditions are triggered, the main turbine is shut down.

[0039] When the main steam turbine is shut down, the back-pressure steam turbine is controlled to continue running.

[0040] The boiler is controlled to operate continuously when at least one of the main steam turbine and the back-pressure steam turbine is in operation.

[0041] Fifthly, this application also provides a computer program product applied to the above-mentioned thermal power unit; the computer program product includes a computer program that, when executed by a processor, performs the following steps:

[0042] The main steam turbine is started when the preset main steam turbine start-up conditions are triggered;

[0043] When the preset main turbine shutdown conditions are triggered, the main turbine is shut down.

[0044] When the main steam turbine is shut down, the back-pressure steam turbine is controlled to continue running.

[0045] The boiler is controlled to operate continuously when at least one of the main steam turbine and the back-pressure steam turbine is in operation.

[0046] In the aforementioned thermal power unit and its operation control method, when the main steam turbine does not need to be started, the steam generated by the boiler can be introduced into the back-pressure steam turbine through the second branch of the first pipeline via an open bypass valve. The back-pressure steam turbine can operate and drive the load under lower steam parameters, thereby converting steam energy that might otherwise be wasted into useful work. When the main steam turbine needs to be started in response to power demand, the main steam valve opens, and the steam can be quickly switched to the main steam turbine operating mode. At this time, the bypass valve can be adjusted or closed according to actual operating needs. Thus, on the one hand, when the main steam turbine does not need to be started, the boiler can continue to operate. Therefore, when the main steam turbine needs to be started to respond to power demand, there is no need to repeat the feedwater pump turbine start-up and boiler ignition process; the main steam turbine start-up stage can be directly entered, thereby significantly shortening the response time of the thermal power unit and improving the power demand response rate. On the other hand, during the main steam turbine shutdown period, the steam continuously generated by the boiler can be effectively utilized by the back-pressure steam turbine, thereby greatly reducing the waste of steam energy. Compared to traditional technologies where the main steam turbine is frequently started and stopped according to power demand, this application can reduce the number of overall start-ups and shutdowns of the thermal power unit, and convert the steam energy that may be lost during the feedwater pump turbine start-up and boiler ignition stages into useful work for the back-pressure turbine to drive the load. This achieves continuous and effective utilization of steam energy under all operating conditions of the thermal power unit, reduces energy venting losses, and improves the overall resource utilization rate of the thermal power unit. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 This is a schematic diagram of the start-up process of a thermal power unit in one embodiment of this application;

[0049] Figure 2 This is a schematic diagram of the structure of a thermal power unit in one embodiment of this application;

[0050] Figure 3 This is a schematic diagram of the structure of a thermal power unit in another embodiment of this application;

[0051] Figure 4 This is a schematic diagram of the structure of the second pipeline in one embodiment of this application;

[0052] Figure 5 This is a structural block diagram of a thermal power unit equipped with a high-pressure heater in one embodiment of this application;

[0053] Figure 6 This is a flowchart illustrating a thermal power unit operation control method in one embodiment of this application;

[0054] Figure 7 This is an internal structural diagram of a computer device in one embodiment of this application. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0056] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0057] It is understood that the terms "first," "second," etc., used in this invention may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this invention, a first conduit may be referred to as a second conduit, and similarly, a second conduit may be referred to as a first conduit. Both the first conduit and the second conduit are conduits, but they are not the same conduit.

[0058] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0059] It is understandable that "at least one" refers to one or more, and "multiple" refers to two or more. "At least a part of an element" refers to part or all of an element.

[0060] When used herein, the singular forms of “a,” “an,” and “ / the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0061] With the rapid development of my country's power industry, thermal power units, as an important component of the power system, have seen significant improvements in their technology and operating efficiency. Thermal power units convert the chemical energy of fuel into the thermal energy of steam, which in turn drives a steam turbine to rotate and power a generator, ultimately achieving a large-scale and stable supply of electricity.

[0062] During the operation of the power system, thermal power units serve as important peak-shaving power sources, participating in power demand response. This means increasing output during peak electricity demand periods and reducing output during off-peak periods to maintain a dynamic balance between power grid supply and demand. In traditional technologies, thermal power units often operate by frequently starting and stopping the entire unit in response to load commands: upon receiving a peak-shaving command from the power grid, the thermal power unit starts to meet load demand, and after the response is completed, it shuts down to await the next command.

[0063] like Figure 1 As shown, the traditional startup process of a thermal power unit typically involves sequentially completing key stages such as feedwater pump turbine start-up, boiler ignition, main turbine start-up, generator grid connection, and load increase, totaling approximately 6.5 hours. Of this, about 5 hours are needed from feedwater pump turbine start-up to the main turbine being ready for start-up. During this period, the basic energy consumption required to maintain system operation is high, and the steam generated after boiler ignition cannot be effectively utilized because the main turbine is not yet ready for start-up; it can only be desuperheated and depressurized through the bypass system before being discharged into the condenser, resulting in significant energy waste.

[0064] It is evident that this operating mode, which involves frequent start-ups and shutdowns of the entire unit in response to power demand, not only results in slow response speed and insufficient operational flexibility of thermal power units, but also causes high energy consumption during start-ups and shutdowns. Furthermore, repeated thermal cycles exacerbate thermal fatigue and mechanical wear of key equipment, ultimately affecting the reliability, economy, and service life of thermal power units.

[0065] In one exemplary embodiment, such as Figure 2 As shown, a thermal power unit is provided, including a boiler 10, a main steam turbine 20, and a back-pressure steam turbine 30. The steam inlet of the main steam turbine 20 is connected to the boiler 10 through a first branch 411 of a first pipeline 41, and a main steam valve 413 is installed on the first branch 411 of the first pipeline 41. The steam inlet of the back-pressure steam turbine 30 is connected to the boiler 10 through a second branch 412 of the first pipeline 41, and a bypass valve 414 is installed on the second branch 412 of the first pipeline 41.

[0066] A thermal power unit is a large-scale power generation device that uses fossil fuels such as coal as its main energy source. Its core function is to gradually convert the chemical energy of the fuel into electrical energy. In addition to the boiler, main steam turbine, and back-pressure steam turbine, the thermal power unit provided in this embodiment may also include a generator and supporting auxiliary systems. All components are closely connected to form a continuous energy conversion chain.

[0067] In some embodiments, a thermal power unit may include a boiler 10, a main steam turbine 20, a back-pressure steam turbine 30, a high-pressure heater 50, a low-pressure heater 60, a first generator 70, a condenser 80, and a deaerator 90, wherein the main steam turbine 20 includes a high-pressure cylinder 21, an intermediate-pressure cylinder 22, and a low-pressure cylinder 23.

[0068] When the main steam turbine 20 is running, the steam generated by the boiler 10 enters the high-pressure cylinder 21 through the first branch of the first pipeline. The high-pressure cylinder 21 can discharge steam into the boiler 10 reheater to form reheated steam. Simultaneously, the high-pressure heater 50 can also extract the discharge steam from the high-pressure cylinder 21 for reheating. The reheated steam discharged from the boiler 10 enters the intermediate-pressure cylinder 22. The intermediate-pressure discharge steam from the intermediate-pressure cylinder 22 enters the low-pressure cylinder 23. Simultaneously, the high-pressure heater 50 can also extract a portion of the discharge steam from the intermediate-pressure cylinder 22 for reheating. The exhaust steam from the low-pressure cylinder 23 enters the condenser 80 and condenses into water. The condensate then sequentially enters the low-pressure heater 60, the deaerator 90, and the high-pressure heater 50, finally returning to the boiler 10, thus realizing the boiler's thermodynamic cycle. The power generated by the first generator 70 comes from the combined work of the high-pressure cylinder 21, the intermediate-pressure cylinder 22, and the low-pressure cylinder 23.

[0069] With the main steam turbine 20 shut down, the back-pressure steam turbine 30 continues to operate. Steam generated by the boiler 10 enters the back-pressure steam turbine 30 through the second branch of the first pipeline. The back-pressure steam turbine 30 can be connected to a generator via a coupling to convert steam energy into electrical energy; it can also directly drive load equipment such as fans and pumps to output mechanical energy; its exhaust steam can also be transported to the heating network or process system for heating or industrial production, thereby realizing the cascade comprehensive utilization of steam thermal energy. At the same time, the high-pressure heater 50 can also extract part of the exhaust steam from the back-pressure steam turbine 30 for reheating.

[0070] In some embodiments, the condenser can be replaced by an air-cooled island.

[0071] In a boiler system, fuel is pulverized and circulated through a coal mill before being fully combusted in the furnace, releasing high-temperature heat energy. The feedwater in the boiler's heating surfaces absorbs heat and undergoes preheating, evaporation, and superheating processes, transforming into high-temperature, high-pressure steam. The steam enters the turbine through the first pipeline, where it expands and performs work in the turbine's flow path, driving the rotor to rotate at high speed, thus converting the steam's thermal and pressure energy into mechanical energy. The turbine rotor can be directly connected to the generator rotor via a coupling, driving the generator rotor to rotate in a magnetic field. Based on the principle of electromagnetic induction, it generates three-phase alternating current (AC) power, which is ultimately transmitted to the power grid via a step-up transformer, enabling long-distance power transmission and supply.

[0072] This process continues under the coordination of the unit control terminal, and continuously optimizes energy utilization efficiency through cycles such as reheating, reheating, and condensation, ultimately completing the full conversion from fuel chemical energy to steam thermal energy, then to mechanical energy, and finally to electrical energy.

[0073] Thermal power units typically include a main steam turbine, which serves as the core of power generation. The main steam turbine is the key equipment responsible for converting the thermal energy of steam into mechanical energy and driving the generator to produce electrical energy.

[0074] Back-pressure steam turbines refer to steam turbines whose exhaust pressure is higher than atmospheric pressure and whose exhaust steam usually does not enter the condenser.

[0075] Back-pressure steam turbines can be connected to generators via couplings to convert steam energy into electrical energy; they can also directly drive load equipment such as fans and pumps to output mechanical energy; their exhaust steam can also be transported to heating networks or process systems for heating or industrial production, thereby realizing the cascaded comprehensive utilization of steam thermal energy.

[0076] However, under pure power generation conditions, its net power generation efficiency is often lower than that of condensing steam turbines or extraction condensing steam turbines with the same steam inlet parameters.

[0077] In terms of power generation capacity, although back-pressure steam turbines can achieve high comprehensive thermal energy utilization efficiency under certain conditions, their power generation scale is usually relatively limited, with common capacities ranging from hundreds of kilowatts to tens of megawatts, significantly smaller than the installed capacity of modern large-scale condensing generator units (which can reach hundreds or even thousands of megawatts). Furthermore, due to operational constraints, back-pressure steam turbines often have limitations in terms of the flexibility and response speed of power generation regulation.

[0078] In contrast, condensing steam turbines and their derivatives, extraction-condensing steam turbines, while potentially having lower overall thermal efficiency than back-pressure units due to condenser cooling losses, can achieve very high single-unit generating capacities; for example, supercritical units can exceed 1000MW. Furthermore, condensing steam turbines typically have a wider load regulation range, operating between 30% and 100% of rated load, allowing for relatively rapid independent output adjustment to better adapt to changes in grid load. Extraction-condensing steam turbines, by adding adjustable extraction ports, can provide some heating capacity while maintaining power supply flexibility, but their independent adjustability of power generation output is generally still higher than that of back-pressure steam turbines.

[0079] Therefore, in mainstream thermal power generation scenarios that require responding to power demands such as grid peak shaving and frequency regulation, the main steam turbine of thermal power units generally tends to be a condensing or extraction-condensing steam turbine, while back-pressure steam turbines are rarely used as the main choice for undertaking the main power supply and regulation tasks of the grid.

[0080] The main steam valve can refer to a shut-off valve installed on the main steam pipeline to connect or disconnect the steam supply to the main steam turbine. It usually has a quick-closing function to protect the turbine safety.

[0081] A bypass valve can refer to a regulating valve installed in parallel with the main steam line, used to direct steam to a second branch of the first pipeline when the first branch of the first pipeline is closed. In some embodiments, the opening degree of the bypass valve is adjustable to control flow rate and pressure.

[0082] Preset main turbine start-up conditions refer to logical judgment conditions set in advance according to the operating procedures and safety standards of thermal power units, which are used to automatically decide when to open the main steam valve.

[0083] Preset main turbine shutdown conditions refer to logical judgment conditions set in advance according to the operating procedures and safety standards of thermal power units, which are used to automatically decide when to close the main steam valve.

[0084] In some embodiments, the preset main turbine start-up condition can be the arrival of a grid peak-shaving command, and the preset main turbine shutdown condition can be the completion of a response according to the grid peak-shaving command.

[0085] For example, when there is no peak-shaving demand on the power grid, the main steam turbine is shut down and the main steam valve is closed. When the main steam valve is closed, the bypass valve remains open, and all the steam generated by the boiler enters the back-pressure steam turbine through the second branch of the first pipeline.

[0086] Upon receiving a peak-shaving command from the power grid, the control terminal can gradually increase the boiler load, raise the main steam pressure and temperature, and simultaneously control the bypass valve to gradually close and the main steam valve to open, guiding at least a portion of the steam through the second branch of the first pipeline to the main steam turbine. The steam then enters the main steam turbine for start-up, speed-up, grid connection, and load increase operations.

[0087] When the main turbine load rises to the target value, the bypass valve can be completely closed or kept slightly open to meet the minimum flow requirement of the back pressure turbine. At this time, the boiler adjusts the combustion according to the total steam demand.

[0088] After responding to the grid peak-shaving command, the control terminal gradually reduces the load on the condensing steam turbine and controls the main steam valve to close. During the closing of the main steam valve, the bypass valve can simultaneously increase its opening to ensure that the steam generated by the boiler is introduced into the back-pressure steam turbine, preventing steam venting.

[0089] After the main steam turbine is completely shut down, the thermal power unit returns to the state when there is no peak-shaving demand in the power grid. The boiler continues to operate, and the back-pressure steam turbine continues to use steam to output mechanical work or thermal energy.

[0090] In some embodiments, if the main steam turbine suddenly trips due to a fault, the main steam valve closes quickly and the bypass valve opens immediately to receive all the steam, thereby preventing boiler overpressure or steam discharge, maintaining the continuous operation of the back-pressure steam turbine, and ensuring uninterrupted power or heat supply within the plant.

[0091] In this embodiment, a thermodynamic structure with two turbines in parallel is constructed by integrating a back-pressure turbine into the traditional main turbine system architecture. Based on the parallel arrangement of the main turbine and the back-pressure turbine on the steam inlet pipeline and the coordinated control between the main steam valve and the bypass valve, continuous and efficient utilization of the steam produced by the boiler under different operating conditions is achieved, thereby basically avoiding steam emission losses caused by the main turbine not being in operation during traditional start-up and shutdown processes.

[0092] Specifically, when the main steam turbine needs to start in response to grid demand, steam supplied by the boiler, which is continuously operating during the back-pressure turbine operation, can be quickly utilized through valve regulation, without undergoing the lengthy temperature and pressure rise process from feedwater pump turbine startup to boiler ignition and steam parameter attainment. This significantly shortens the time for thermal power units to respond to grid demands. For example, in situations such as... Figure 1 In the thermal power unit startup scenario shown, the traditional method requires a total of about six and a half hours, while this embodiment may only require one to two hours, reducing the total time by about 5 hours.

[0093] Furthermore, the boiler operates continuously during peak-shaving intervals, reducing thermal cycling changes caused by frequent start-ups and shutdowns. This helps alleviate thermal fatigue damage to thick-walled pressure-bearing components such as the steam drum and headers, improving the long-term reliability of the equipment. During this period, the back-pressure turbine effectively converts the boiler steam to provide electricity or heat for the power plant itself. This achieves cascaded energy utilization while reducing the plant's power consumption rate, thereby improving the overall energy efficiency and economy of the power plant.

[0094] In this embodiment, when the main turbine does not need to be started, the steam generated by the boiler can be introduced into the back-pressure turbine through the second branch of the first pipeline via an open bypass valve. The back-pressure turbine can operate and drive the load under lower steam parameters, thereby converting steam energy that might otherwise be wasted into useful work. When the main turbine needs to be started in response to power demand, the main steam valve opens, and the steam can be quickly switched to the main turbine operating mode. At this time, the bypass valve can be adjusted or closed according to actual operating needs. Thus, on the one hand, when the main turbine does not need to be started, the boiler can continue to operate. Therefore, when the main turbine needs to be started to respond to power demand, there is no need to repeat the feedwater pump turbine start-up and boiler ignition process; the main turbine start-up stage can be directly entered, thereby significantly shortening the response time of the thermal power unit and improving the power demand response rate. On the other hand, during the main turbine shutdown period, the steam continuously generated by the boiler can be effectively utilized by the back-pressure turbine, thereby greatly reducing the waste of steam energy. Compared to traditional technologies where the main steam turbine is frequently started and stopped according to power demand, this application can reduce the number of overall start-ups and shutdowns of the thermal power unit, and convert the steam energy that may be lost during the feedwater pump turbine start-up and boiler ignition stages into useful work for the back-pressure turbine to drive the load. This achieves continuous and effective utilization of steam energy under all operating conditions of the thermal power unit, reduces energy venting losses, and improves the overall resource utilization rate of the thermal power unit.

[0095] This embodiment, by reconstructing the unit's thermal system structure and operational control logic, significantly improves operational economy, environmental friendliness, and flexibility across all operating conditions while achieving rapid start-up and shutdown response. Maintaining continuous operation of the boiler and back-pressure turbine during main turbine start-up and shutdown and low-load phases effectively reduces the severe temperature cycling and thermal stress alternation caused by frequent start-ups and shutdowns of critical thick-walled components. This reduces the rate of metal fatigue accumulation, extends equipment service life, and reduces the risk of damage such as cracks and deformation caused by thermal fatigue. Simultaneously, this operating mode can significantly reduce or even avoid the fuel consumption, purchased auxiliary steam, and high plant power consumption necessary to maintain system temperature and pressure during traditional start-up and shutdown processes, directly lowering the unit's operating costs and energy consumption levels.

[0096] By putting the high and low pressure heater systems into operation in advance, the steam-water system can be effectively flushed during the boiler ignition and pipe blowing stage, significantly shortening the time for the steam-water quality to meet the standards, and the silicon washing process can be completed before the steam turbine is rotated. This not only improves the safety of boiler operation during the start-up and shutdown stages, but also greatly shortens the time for the unit to go from grid connection to full load. At the same time, since all heaters can be put into operation before grid connection, the feed water temperature can be quickly raised to 150 - 170°C. Combined with the design of the staged economizer, etc., the denitration system can meet the operation conditions before grid connection, achieving stable denitration within the full load range.

[0097] In terms of operation flexibility, the method of shutting down the turbine without stopping the boiler can greatly reduce the safety risks and equipment fatigue caused by frequent start-up and shutdown of the boiler, and significantly improve the reliability and rapid response ability of the unit under deep peak shaving conditions. This characteristic is especially suitable for thermal power projects supporting large-scale new energy bases in deserts, gobi, and wastelands, enabling them to effectively suppress the volatility and randomness of new energy power generation, enhance the safety and stability of the power grid, and thus effectively promote the consumption of new energy.

[0098] From the perspective of system benefits, by improving the peak shaving flexibility and operation efficiency of the unit, on the one hand, it increases the space for new energy acceptance, and on the other hand, it reduces the coal consumption for power generation of the unit by optimizing the thermal cycle, achieving a double reduction in carbon consumption and carbon dioxide emissions, providing a practical technical path for the low-carbon transformation of the power industry and the implementation of the "dual carbon" goal. In summary, this embodiment not only enhances the economic and environmental performance of the thermal power unit itself, but also provides an important technical support for building a safe, reliable, flexible and efficient new power system.

[0099] In an exemplary embodiment, the thermal power unit further includes a second generator, and the back-pressure steam turbine is connected to the second generator, and the second generator is configured to generate electricity driven by the back-pressure steam turbine.

[0100] It should be noted that during the start-up and shutdown or low-load operation of traditional thermal power units, if the boiler remains in operation to maintain steam supply while the main steam turbine has not been started or is in a low-output state, the steam generated at this time often passes through the bypass system for temperature reduction and pressure reduction and is directly discharged into the condenser, resulting in a large amount of high-quality heat energy being dissipated ineffectively, which can neither be converted into electric energy nor be effectively utilized by external systems. Although some units can utilize part of the steam through the extraction steam for heating, when in the pure condensing condition or without a stable heat load, the energy of this part of the steam still cannot be effectively recovered, resulting in a decline in the overall energy utilization rate.

[0101] Among them, the second generator may refer to a rotating electrical machine device specifically connected to the back-pressure steam turbine and used to convert the mechanical energy output by the steam turbine into electric energy.

[0102] For example, the back-pressure steam turbine can be connected to a separate second generator via a coupling. This second generator is electrically connected to the plant power bus or has an independent grid connection interface. When the main steam turbine is shut down or under low load, the main steam valve is closed and the bypass valve is open. Steam generated by the boiler enters the back-pressure steam turbine through the second branch of the first pipeline, driving its rotor to rotate. The back-pressure steam turbine directly drives the rotor of the second generator to reach its rated speed. The control terminal controls the second generator to complete excitation and voltage establishment, and then automatically synchronizes and connects to the plant power grid or a designated power grid to output electrical energy.

[0103] In this embodiment, by adding a second generator directly connected to the back-pressure turbine, when the main turbine is not running or under low load, the steam generated by the boiler can drive the back-pressure turbine to power the second generator continuously, converting the steam heat energy that might otherwise be discarded into usable electrical energy. This significantly reduces energy loss during start-up and shutdown of the thermal power unit and under low load conditions, improving the overall plant energy utilization rate. Secondly, the electricity generated by the second generator can be directly used to power auxiliary equipment within the plant or sold to the grid, reducing the plant's power consumption rate or creating additional power generation revenue, thus improving the unit's operating economy. Furthermore, the introduction of the back-pressure turbine and the second generator can enhance the flexibility and reliability of the thermal power unit's operation. When the main turbine is under maintenance or malfunctions, partial power output can still be maintained through the back-pressure turbine and the second generator, ensuring the continuity of the plant's base load, external heating, or external power supply.

[0104] In one exemplary embodiment, such as Figure 4 As shown, the main steam turbine 20 includes a high-pressure cylinder 21, and the steam inlet end of the main steam turbine 20 includes the steam inlet end of the high-pressure cylinder 21; the steam inlet end of the high-pressure cylinder 21 is connected to the boiler 10 through the first branch 411 of the first pipeline 41; the first steam outlet end of the high-pressure cylinder 21 is connected to the second branch 412 of the first pipeline 41 through the second pipeline 42, and the bypass valve 414 is located between the connection port of the second pipeline 42 and the branch junction of the first pipeline 41.

[0105] The second pipeline can refer to the exhaust pipe of the second branch used to connect the first steam outlet of the high-pressure cylinder to the first pipeline, and is used to guide the exhaust steam of the high-pressure cylinder to the steam inlet branch of the back-pressure steam turbine.

[0106] In some embodiments, a one-way valve may be provided at the first steam outlet of the high-pressure cylinder, that is, only allowing the high-pressure cylinder to exhaust gas into the second pipeline.

[0107] In some embodiments, a valve may be provided on the second access route to regulate the exhaust flow rate of the high-pressure cylinder to the inlet branch of the back-pressure steam turbine.

[0108] A connection port can refer to the location where the second pipeline connects to the second branch of the first pipeline.

[0109] A branch junction can refer to the fork in the first pipeline where the first branch branch and the second branch branch diverge.

[0110] For example, when the main steam valve is open, the steam generated by the boiler can enter the high-pressure cylinder through the second branch of the first pipeline. As the steam flow into the high-pressure cylinder increases, the high-pressure cylinder begins to accelerate. With the second pipeline in place, when the main steam valve is open, the bypass valve can be gradually closed, and the back-pressure turbine can be maintained by using the exhaust steam from the high-pressure cylinder. In this way, when the main steam turbine is shut down, the continuous operation of the back-pressure turbine can maintain the boiler's rapid response capability.

[0111] After the main steam valve is opened, the bypass valve can be closed slightly until the high-pressure cylinder exhausts steam to the back-pressure turbine through the second pipeline, at which point the bypass valve can be completely closed.

[0112] In this embodiment, the steam directly generated by the boiler has a higher work capacity. However, using it in a back-pressure turbine, which has a relatively low capacity and efficiency, fails to fully utilize its high-grade energy potential for higher conversion efficiency in the main turbine. In contrast, the exhaust steam from the high-pressure cylinder is medium-parameter steam that has already performed some work in the high-pressure section of the main turbine, and its thermodynamic grade has been appropriately reduced. By introducing this exhaust steam to the back-pressure turbine as a driving steam source through a second pipeline, the energy is utilized in a cascade manner. The high-grade energy is used to generate electricity efficiently in the main turbine, while the medium- and low-grade waste heat is reused in the back-pressure turbine.

[0113] In one exemplary embodiment, a first valve is provided on the second pipeline, and the first valve is in the open state when the bypass valve is in the closed state.

[0114] The first valve can refer to a shut-off or regulating valve installed on the second pipeline to connect or disconnect the steam flow in that pipeline. Its opening and closing states are logically linked with the bypass valve.

[0115] For example, a first valve is installed on the second pipeline connecting the first steam outlet of the high-pressure cylinder and the second branch of the first pipeline. In the control terminal, the control logic of the first valve can be set to interlock with the bypass valve: when the bypass valve receives a closing command or feedback signal indicating a closed state, the control terminal can automatically issue an opening command to the first valve; conversely, when the bypass valve is open, the first valve can be closed or kept open according to actual operating requirements.

[0116] When the thermal power unit primarily generates electricity using the main steam turbine, the bypass valve is closed. At this time, the interlocking logic triggers the first valve to open automatically. While the exhaust steam from the high-pressure cylinder flows to the reheater or intermediate-pressure cylinder, at least a portion of it passes through the second pipeline and merges into the second branch of the first pipeline, serving as the main steam source for the back-pressure steam turbine to drive its continuous operation for power generation or heating.

[0117] When the main steam turbine is shut down or during the initial startup phase, the bypass valve is open, and fresh steam from the boiler is directly supplied to the back-pressure turbine via the second branch. At this time, according to the interlocking logic or operating procedures, the first valve can automatically close or be placed in a small-open isolation state to cut off the passage of high-pressure cylinder exhaust steam to the second branch, preventing steam backflow or interference with the independent operating parameters of the back-pressure turbine, while ensuring the safety of the high-pressure cylinder and subsequent systems.

[0118] In some embodiments, when the bypass valve is open, the main steam valve is closed or about to close. When the main steam valve is closed and the second pipeline only allows steam to flow from the high-pressure cylinder to the back-pressure turbine, whether the first valve is closed has little impact on the steam flow direction.

[0119] In this embodiment, by adding a first valve on the second pipeline that is interlocked with the bypass valve, orderly and controllable management of the passage from the high-pressure cylinder exhaust to the back-pressure turbine is achieved.

[0120] In an exemplary embodiment, the thermal power unit further includes a first high-pressure heater, a second high-pressure heater, and a third high-pressure heater; the main steam turbine also includes an intermediate-pressure cylinder; the first high-pressure heater is connected to the first extraction end of the high-pressure cylinder via a third pipeline; the second high-pressure heater is connected to the second extraction end of the high-pressure cylinder via a first branch of a fourth pipeline, and is also connected to the first extraction end of the back-pressure steam turbine via a second branch of the fourth pipeline; the third high-pressure heater is connected to the first extraction end of the intermediate-pressure cylinder via a first branch of a fifth pipeline, and is also connected to the second extraction end of the back-pressure steam turbine via a second branch of the fifth pipeline.

[0121] High-pressure heaters can refer to surface heat exchangers located after the feedwater pump and before the boiler, using steam extracted from the turbine to heat the boiler feedwater and improve circulation efficiency. High-pressure heaters can be numbered according to feedwater flow direction or extraction steam pressure, with smaller numbers corresponding to higher extraction steam pressures. For example, the extraction steam pressure corresponding to the first high-pressure heater is higher than that corresponding to the second high-pressure heater.

[0122] The extraction end can refer to the interface opened on the cylinder or connecting pipe of a steam turbine, used to extract the steam that has partially expanded and done work.

[0123] For example, a thermal power unit is equipped with three high-pressure heaters, namely a first high-pressure heater, a second high-pressure heater, and a third high-pressure heater. The main steam turbine includes at least a high-pressure cylinder and an intermediate-pressure cylinder, and may also include a low-pressure cylinder. A back-pressure steam turbine is equipped with at least two extraction ends, namely a first extraction end and a second extraction end.

[0124] The only steam source for the first high-pressure heater comes from the first extraction end of the high-pressure cylinder, which is connected through a third pipeline.

[0125] The second high-pressure heater has dual steam sources, one from the second extraction end of the high-pressure cylinder and the other from the first extraction end of the back-pressure turbine. The second high-pressure heater is connected to the second extraction end of the high-pressure cylinder via the first branch of the fourth pipeline, and to the first extraction end of the back-pressure turbine via the second branch of the fourth pipeline. The two branches converge before the heater.

[0126] In an exemplary embodiment, a second valve is provided on the first branch of the fourth pipeline, and a third valve is provided on the second branch of the fourth pipeline, for switching of steam source or proportional adjustment.

[0127] The third high-pressure heater also has dual steam sources, one from the first extraction end of the intermediate-pressure cylinder and the other from the second extraction end of the back-pressure turbine. The third high-pressure heater is connected to the first extraction end of the intermediate-pressure cylinder via the first branch of the fifth pipeline, and to the second extraction end of the back-pressure turbine via the second branch of the fifth pipeline. The two branches converge before the heater.

[0128] In one exemplary embodiment, a fourth valve is provided on the first branch of the fifth pipeline, and a fifth valve is provided on the second branch of the fifth pipeline, for switching of steam source or proportional adjustment.

[0129] In one exemplary embodiment, when the bypass valve or the first valve is in the open state, the second valve is in the open state, the third valve is in the closed state, the fourth valve is in the closed state, and the fifth valve is in the open state.

[0130] For example, valve interlocking logic based on the states of the bypass valve and the first valve can be pre-set in the control terminal to automatically control the opening and closing states of the second to fifth valves. When the bypass valve or the first valve is open, it indicates that the back-pressure turbine can receive steam from the boiler or exhaust steam from the high-pressure cylinder, that is, the back-pressure turbine is in operation or start-up state. At this time, the interlocking logic is automatically set: the second valve opens, the third valve closes, the fourth valve closes, and the fifth valve opens.

[0131] In one exemplary embodiment, when both the bypass valve and the first valve are closed, the second valve is closed, the third valve is open, the fourth valve is closed, and the fifth valve is open.

[0132] For example, valve interlocking logic based on the states of the bypass valve and the first valve can be pre-set in the control terminal to automatically control the opening and closing states of the second to fifth valves. When both the bypass valve and the first valve are closed, it indicates that the back-pressure turbine is not receiving steam from the boiler or exhaust steam from the high-pressure cylinder, and may be in an isolated or shut-down state. The main turbine may be operating alone, or the thermal power unit may be in a state of complete shutdown. At this time, the interlocking logic is automatically set: the second valve is closed, the third valve is opened, the fourth valve is closed, and the fifth valve is opened.

[0133] In this embodiment, during the thermal system design and operation optimization, the high-pressure cylinder extraction steam, due to its high pressure and temperature parameters, provides the high-grade thermal energy required for heating the feedwater, which is difficult to completely replace by the lower-parameter extraction steam of the back-pressure turbine. To ensure that the boiler feedwater can be heated to the design temperature and maintain cycle thermal efficiency, the first and second high-pressure heaters still preferentially use the extraction steam from the high-pressure cylinder as the heating steam source during the operation of the main turbine. Meanwhile, the heating steam required by the third high-pressure heater is of medium-to-low grade thermal energy, and its parameter range matches the extraction steam parameters of the back-pressure turbine. Therefore, under the operating conditions of the back-pressure turbine, the extraction steam from the back-pressure turbine can be used to replace the extraction steam traditionally provided by the intermediate-pressure cylinder to meet the heating needs of the third high-pressure heater by switching valves. In this way, the steam that originally needed to be extracted from the intermediate-pressure cylinder for heating can be retained, allowing it to continue to enter the low-pressure cylinder for expansion and work, thereby increasing the power generation output of the main turbine. This allows for efficient cascade utilization of energy while maintaining the heating effect of the feedwater heating system. It converts the usable extracted steam generated during the operation of the back-pressure steam turbine into additional power generation revenue, effectively improving the overall power generation and comprehensive energy utilization efficiency of the power plant.

[0134] In an exemplary embodiment, the thermal power unit further includes a deaerator; the deaerator is connected to the second extraction end of the intermediate pressure cylinder via a first branch of the sixth pipeline; the deaerator is connected to the third extraction end of the back pressure turbine via a second branch of the sixth pipeline.

[0135] Among them, the deaerator is a hybrid thermal device used to remove dissolved oxygen and other non-condensable gases from boiler feedwater using the principle of thermal deaeration. At the same time, it serves as an important heating unit in the feedwater system to increase the feedwater temperature.

[0136] In thermal system design, the deaerator only needs to heat the boiler feedwater to the saturation temperature corresponding to its operating pressure. This saturation temperature is relatively low; therefore, the deaerator is essentially a thermal device with low requirements for heat energy grade. High-pressure cylinder extraction steam, as a high-grade heat source in the main turbine system, typically has a pressure much higher than the deaerator's design operating pressure and possesses high usable energy. If this high-parameter steam is directly used in the deaerator, its pressure and temperature need to be significantly reduced at the deaerator inlet or through pipeline throttling to meet the deaerator's pressure matching requirements. This process essentially converts the work potential of high-quality steam into low-grade heat energy through an irreversible throttling and mixing process, resulting in the high-grade energy being severely degraded without being used for useful work, thereby reducing the overall work capacity and thermal economy of the entire thermal cycle.

[0137] Therefore, deaerators typically use steam extracted from the intermediate-pressure cylinder as their steam source.

[0138] For example, the deaerator is provided with a heating steam inlet, which is connected to two steam sources through a sixth pipeline. The first branch of the sixth pipeline is connected to the second extraction end of the intermediate pressure cylinder, and the second branch of the sixth pipeline is connected to the third extraction end of the back pressure steam turbine.

[0139] In an exemplary embodiment, a sixth valve is provided on the first branch of the sixth pipeline; a seventh valve is provided on the second branch of the sixth pipeline for switching the steam source and controlling the flow.

[0140] In one exemplary embodiment, when the bypass valve or the first valve is in the open state, the sixth valve is in the closed state and the seventh valve is in the open state.

[0141] For example, valve interlocking logic based on the states of the bypass valve and the first valve can be pre-set in the control terminal to automatically control the opening and closing states of the sixth and seventh valves. When the bypass valve or the first valve is open, it indicates that the back-pressure turbine can receive steam from the boiler or exhaust steam from the high-pressure cylinder, meaning the back-pressure turbine is in operation or startup mode. At this time, the interlocking logic is automatically set: the sixth valve is closed, and the seventh valve is opened.

[0142] In one exemplary embodiment, when both the bypass valve and the first valve are closed, the sixth valve is open and the seventh valve is closed.

[0143] For example, valve interlocking logic based on the states of the bypass valve and the first valve can be pre-set in the control terminal to automatically control the opening and closing states of the sixth and seventh valves. When both the bypass valve and the first valve are closed, it indicates that the back-pressure turbine is not receiving steam from the boiler or exhaust steam from the high-pressure cylinder, and may be in an isolated or shut-down state. The main turbine may be operating alone, or the thermal power unit may be in a state of complete shutdown. At this time, the interlocking logic is automatically set: the sixth valve is opened and the seventh valve is closed.

[0144] In this embodiment, during the operation of the thermal system, the deaerator, as a key device for ensuring feedwater quality and maintaining circulation efficiency, requires a stable and parameter-matched heating steam source. The extraction steam parameters of the back-pressure turbine are typically in the low-to-medium grade range, which has good matching properties with the heating steam pressure and temperature requirements of the deaerator. When the back-pressure turbine is in operation, its extraction steam is preferentially used as the heating steam source for the deaerator. This not only meets the thermal energy demand of the deaerator but also transfers the heating task undertaken by the intermediate-pressure cylinder extraction steam to the back-pressure turbine, thereby retaining the extraction steam in the corresponding part of the intermediate-pressure cylinder. When this part of the intermediate-pressure cylinder extraction steam is not needed for heating the deaerator, it can continue to expand downstream along the flow path to the low-pressure cylinder, driving more blades to do work and converting it into additional power generation output. When the back-pressure turbine is shut down or extraction steam is unavailable, the system can automatically switch to supplying steam to the deaerator from the intermediate-pressure cylinder extraction steam, ensuring the continuous and stable feedwater heating and deaeration processes. This not only ensures that the unit maintains a stable deoxygenation effect under different operating conditions, but also improves the overall power generation output and overall energy utilization efficiency of the plant without increasing additional fuel consumption by effectively integrating and optimizing the extraction energy of the back-pressure steam turbine.

[0145] Based on the same inventive concept, this application also provides a method for operating control of thermal power units applied to the aforementioned thermal power units. The solution provided by this method is similar to the solution described in the above-described thermal power units. Therefore, the specific limitations in one or more embodiments of the thermal power unit operation control method provided below can be found in the limitations on thermal power units described above, and will not be repeated here.

[0146] In one exemplary embodiment, such as Figure 6As shown, a method for controlling the operation of a thermal power unit is provided. This embodiment illustrates the application of this method to a terminal, where the terminal can be the control terminal of the aforementioned thermal power unit. This control terminal can be integrated into the thermal power unit, or it can be, but is not limited to, various personal computers, laptops, smartphones, tablets, IoT devices, and portable wearable devices capable of communicating with the thermal power unit. IoT devices can include smart speakers, smart TVs, smart air conditioners, smart vehicle devices, projection devices, etc. Portable wearable devices can include smartwatches, smart bracelets, head-mounted devices, etc. Head-mounted devices can be virtual reality (VR) devices, augmented reality (AR) devices, smart glasses, etc. It is understood that this method can also be applied to a server, and can also be applied to a system including both a terminal and a server, and implemented through the interaction between the terminal and the server. In this embodiment, the method includes steps 602 to 608. Wherein:

[0147] Step 602: When the preset main turbine start-up conditions are triggered, start the main turbine;

[0148] Step 604: When the preset main turbine shutdown condition is triggered, control the main turbine to shut down;

[0149] Step 606: When the main steam turbine is in a shutdown state, control the back pressure steam turbine to continue running;

[0150] Step 608: When at least one of the main steam turbine and the back-pressure steam turbine is in operation, control the boiler to continue operating.

[0151] In an exemplary embodiment, the thermal power unit further includes a first generator, with the main steam turbine connected to the first generator; the method further includes:

[0152] Control the main steam turbine to drive the first generator to generate electricity.

[0153] In an exemplary embodiment, the thermal power unit further includes a second generator, to which a back-pressure steam turbine is connected; the method further includes:

[0154] The back-pressure steam turbine drives the second generator to generate electricity.

[0155] In an exemplary embodiment, the main steam turbine includes a high-pressure cylinder, and the steam inlet end of the main steam turbine includes the steam inlet end of the high-pressure cylinder; the steam inlet end of the high-pressure cylinder is connected to the boiler through a first branch of a first pipeline; the first steam outlet end of the high-pressure cylinder is connected to a second branch of the first pipeline through a second pipeline, and a bypass valve is located between the connection port of the second pipeline and the branch junction of the first pipeline.

[0156] In one exemplary embodiment, a first valve is provided on the second pipeline; the method further includes:

[0157] When the bypass valve is closed, the first control valve is in the open state.

[0158] In an exemplary embodiment, the thermal power unit further includes a first high-pressure heater, a second high-pressure heater, and a third high-pressure heater; the main steam turbine also includes an intermediate-pressure cylinder; the first high-pressure heater is connected to the first extraction end of the high-pressure cylinder via a third pipeline; the second high-pressure heater is connected to the second extraction end of the high-pressure cylinder via a first branch of a fourth pipeline, and is also connected to the first extraction end of the back-pressure steam turbine via a second branch of the fourth pipeline; the third high-pressure heater is connected to the first extraction end of the intermediate-pressure cylinder via a first branch of a fifth pipeline, and is also connected to the second extraction end of the back-pressure steam turbine via a second branch of the fifth pipeline.

[0159] In an exemplary embodiment, a second valve is provided on the first branch of the fourth pipeline, and a third valve is provided on the second branch of the fourth pipeline; a fourth valve is provided on the first branch of the fifth pipeline, and a fifth valve is provided on the second branch of the fifth pipeline; the method further includes:

[0160] When the bypass valve or the first valve is in the open state, the second valve is controlled to be in the open state, the third valve is in the closed state, the fourth valve is in the closed state, and the fifth valve is in the open state.

[0161] When both the bypass valve and the first valve are closed, the second valve is closed, the third valve is open, the fourth valve is closed, and the fifth valve is open.

[0162] In an exemplary embodiment, the thermal power unit further includes a deaerator; the deaerator is connected to the second extraction end of the intermediate pressure cylinder via a first branch of the sixth pipeline; the deaerator is connected to the third extraction end of the back pressure turbine via a second branch of the sixth pipeline.

[0163] In an exemplary embodiment, a sixth valve is provided on the first branch of the sixth pipeline; a seventh valve is provided on the second branch of the sixth pipeline; the method further includes:

[0164] When the bypass valve or the first valve is in the open state, the sixth valve is controlled to be in the closed state and the seventh valve is controlled to be in the open state.

[0165] When both the bypass valve and the first valve are closed, the sixth valve is opened and the seventh valve is closed.

[0166] In this embodiment, when the main turbine does not need to be started, the steam generated by the boiler can be introduced into the back-pressure turbine through the second branch of the first pipeline via an open bypass valve. The back-pressure turbine can operate and drive the load under lower steam parameters, thereby converting steam energy that might otherwise be wasted into useful work. When the main turbine needs to be started in response to power demand, the main steam valve opens, and the steam can be quickly switched to the main turbine operating mode. At this time, the bypass valve can be adjusted or closed according to actual operating needs. Thus, on the one hand, when the main turbine does not need to be started, the boiler can continue to operate. Therefore, when the main turbine needs to be started to respond to power demand, there is no need to repeat the feedwater pump turbine start-up and boiler ignition process; the main turbine start-up stage can be directly entered, thereby significantly shortening the response time of the thermal power unit and improving the power demand response rate. On the other hand, during the main turbine shutdown period, the steam continuously generated by the boiler can be effectively utilized by the back-pressure turbine, thereby greatly reducing the waste of steam energy. Compared to traditional technologies where the main steam turbine is frequently started and stopped according to power demand, this application can reduce the number of overall start-ups and shutdowns of the thermal power unit, and convert the steam energy that may be lost during the feedwater pump turbine start-up and boiler ignition stages into useful work for the back-pressure turbine to drive the load. This achieves continuous and effective utilization of steam energy under all operating conditions of the thermal power unit, reduces energy venting losses, and improves the overall resource utilization rate of the thermal power unit.

[0167] It should be understood that although the steps in the flowcharts of the above embodiments are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0168] Based on the same inventive concept, this application also provides a thermal power unit operation control device for implementing the above-mentioned thermal power unit operation control method. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations in one or more embodiments of the thermal power unit operation control device provided below can be found in the limitations of the thermal power unit operation control method described above, and will not be repeated here.

[0169] In one exemplary embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 7As shown, the computer device includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The input / output interface is used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, Near Field Communication (NFC), or other technologies. When the computer program is executed by the processor, it implements a method for controlling the operation of a thermal power unit. The display unit is used to form a visually visible image and can be a display screen, projection device, or virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the computer device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the computer device, or external keyboards, touchpads, or mice, etc.

[0170] Those skilled in the art will understand that Figure 7 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0171] In one embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above method embodiments.

[0172] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the steps in the above method embodiments.

[0173] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0174] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0175] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, database, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0176] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0177] The above embodiments merely illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this application's patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A thermal power unit, characterized in that, The thermal power unit includes a boiler, a main steam turbine, and a back-pressure steam turbine, wherein: The boiler operates continuously when at least one of the main steam turbine and the back-pressure steam turbine is in operation; The steam inlet of the main steam turbine is connected to the boiler through the first branch of the first pipeline. A main steam valve is provided on the first branch of the first pipeline. The main steam valve opens when the preset main steam turbine start-up conditions are met and closes when the preset main steam turbine shutdown conditions are met. The steam inlet of the back-pressure steam turbine is connected to the boiler via a second branch of the first pipeline. A bypass valve is provided on the second branch of the first pipeline. When the main steam valve is closed, the bypass valve is open.

2. The thermal power unit according to claim 1, characterized in that, The thermal power unit also includes a first generator, the main steam turbine is connected to the first generator, and the first generator is configured to generate electricity under the drive of the main steam turbine.

3. The thermal power unit according to claim 1, characterized in that, The thermal power unit also includes a second generator, and the back-pressure steam turbine is connected to the second generator, which is configured to generate electricity under the drive of the back-pressure steam turbine.

4. The thermal power unit according to claim 1, characterized in that, The main steam turbine includes a high-pressure cylinder, and the steam inlet end of the main steam turbine includes the steam inlet end of the high-pressure cylinder; the steam inlet end of the high-pressure cylinder is connected to the boiler through a first branch of a first pipeline; The first steam outlet of the high-pressure cylinder is connected to the second branch of the first pipeline via a second pipeline, and the bypass valve is located between the connection port of the second pipeline and the branch junction of the first pipeline.

5. The thermal power unit according to claim 4, characterized in that, The second pipeline is equipped with a first valve, which is in the open state when the bypass valve is in the closed state.

6. The thermal power unit according to claim 5, characterized in that, The thermal power unit also includes a first high-pressure heater, a second high-pressure heater, and a third high-pressure heater; the main steam turbine also includes an intermediate-pressure cylinder; The first high-pressure heater is connected to the first extraction end of the high-pressure cylinder via a third pipeline; The second high-pressure heater is connected to the second extraction end of the high-pressure cylinder through the first branch of the fourth pipeline, and the second high-pressure heater is connected to the first extraction end of the back-pressure steam turbine through the second branch of the fourth pipeline. The third high-pressure heater is connected to the first extraction end of the intermediate-pressure cylinder through the first branch of the fifth pipeline, and the third high-pressure heater is connected to the second extraction end of the back-pressure steam turbine through the second branch of the fifth pipeline.

7. The thermal power unit according to claim 6, characterized in that, A second valve is installed on the first branch of the fourth pipeline, and a third valve is installed on the second branch of the fourth pipeline; a fourth valve is installed on the first branch of the fifth pipeline, and a fifth valve is installed on the second branch of the fifth pipeline. When the bypass valve or the first valve is in the open state, the second valve is in the open state, the third valve is in the closed state, the fourth valve is in the closed state, and the fifth valve is in the open state; When both the bypass valve and the first valve are closed, the second valve is closed, the third valve is open, the fourth valve is closed, and the fifth valve is open.

8. The thermal power unit according to claim 6, characterized in that, The thermal power unit also includes a deaerator; the deaerator is connected to the second extraction end of the intermediate pressure cylinder via the first branch of the sixth pipeline; the deaerator is connected to the third extraction end of the back pressure steam turbine via the second branch of the sixth pipeline.

9. The thermal power unit according to claim 8, characterized in that, A sixth valve is installed on the first branch of the sixth pipeline; a seventh valve is installed on the second branch of the sixth pipeline; When the bypass valve or the first valve is in the open state, the sixth valve is in the closed state and the seventh valve is in the open state; When both the bypass valve and the first valve are closed, the sixth valve is open and the seventh valve is closed.

10. A method for controlling the operation of a thermal power unit, characterized in that, Applied to the thermal power unit according to any one of claims 1 to 9; the method includes: When the preset main steam turbine start-up conditions are triggered, the main steam turbine is started. When the preset main turbine shutdown condition is triggered, the main turbine is controlled to shut down; When the main steam turbine is in a shutdown state, the back-pressure steam turbine is controlled to continue running; When at least one of the main steam turbine and the back-pressure steam turbine is in operation, the boiler is controlled to operate continuously.

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