Structure of soot blowing gas source for ultra-supercritical parameter coal-fired steam turbine generator set boiler

Abstract

The utility model relates to the technical field of generator set soot blowing equipment, specifically discloses a structure for the boiler soot blowing gas source of ultra supercritical parameter coal-fired steam turbine generator set, including the main steam source of reheater output, set up in the first pipeline and second pipeline of low reentry, the first pipeline and second pipeline are converged into third pipeline at export end, are equipped with cut -off valve, first electric cut -off valve and pneumatic pressure regulating valve in proper order on third pipeline, still be equipped with temperature measuring equipment on third pipeline, third pipeline export end is connected to soot blowing steam source station directly, still be equipped with control pipeline on third pipeline, be equipped with pressure transmitter on control pipeline, pressure transmitter export end is connected to soot blowing gas source station pipeline, the present application can satisfy soot blowing demand, reduce heat loss, improve equipment operation reliability and economy, reduce valve failure risk, reduce potential safety hazard.

Description

Technical Field

[0001] This utility model relates to the field of generator set equipment technology, specifically to a structure for a soot blowing gas source for a coal-fired steam turbine generator set with ultra-supercritical parameters. Background Technology

[0002] In large coal-fired power plants, especially ultra-supercritical units, maintaining the cleanliness of boiler heating surfaces is crucial. Boiler soot blowing, as a key means of removing ash accumulation, ensuring efficient heat exchange of heating surfaces, preventing flue gas passage blockage, and preventing high-temperature corrosion of equipment, directly affects the safety, economy, and environmental performance of the unit operation.

[0003] Currently, due to the operating characteristics and ash accumulation characteristics of the boiler's high-temperature zone, to ensure the high enthalpy and high kinetic energy requirements of the steam source for soot blowing, these units generally adopt steam soot blowing technology, with the steam source mostly drawn from the inlet pipe of the boiler's screen-type high-temperature superheater. The steam here represents the highest grade energy produced by the boiler, possessing extremely high pressure and temperature, with a large flow rate and stable pressure, capable of meeting soot blowing needs at any time and ensuring the safety protection requirements of the high-temperature heating surfaces. However, as shown in the attached... Figure 3 As shown, this high-grade steam, when used directly in soot blowing operations, must undergo significant cooling and pressure reduction before application to meet the operating requirements of the soot blowing system. This process not only results in a significant waste of usable energy from the high-quality steam and substantial heat loss, reducing the overall power generation efficiency of the unit and leading to poor economic performance, but also causes a huge pressure difference during the pressure reduction process. This results in related valves being subjected to harsh operating conditions for extended periods, leading to accelerated wear, frequent malfunctions, and severely impacting the reliability of the soot blowing system and even the unit's operation.

[0004] Therefore, there is a need to find a soot blowing structure that can both ensure effective soot blowing and improve the operating economy and system reliability of current ultra-supercritical coal-fired power units. Utility Model Content

[0005] The present invention aims to provide a soot blowing gas source structure for a coal-fired steam turbine generator set with ultra-supercritical parameters, in order to solve the problem that the existing steam source structure requires a significant cooling and decompression after steam is taken in before it can be used for steam soot blowing, which greatly reduces economic efficiency and is prone to frequent valve failures in the system.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: This utility model provides a soot blowing gas source structure for a boiler in an ultra-supercritical coal-fired turbine generator set. By extracting steam from the low reheat inlet as the soot blowing gas source, it effectively saves high-grade steam for power generation, improving the unit's economic efficiency, while simultaneously reducing pressure differential and improving system operational reliability. Specifically, the structure includes a main steam source output from the reheater, a first pipeline and a second pipeline located at the low reheat inlet. The first and second pipelines merge at the outlet to form a third pipeline. A shut-off valve, a first electrically operated shut-off valve, and a pneumatic pressure regulating valve are sequentially installed on the third pipeline. A temperature measuring device is also installed on the third pipeline. The outlet of the third pipeline is directly connected to the soot blowing gas source station. A control pipeline is also provided on the third pipeline, and a pressure transmitter is installed on the control pipeline. The outlet of the pressure transmitter is connected to the soot blowing gas source station pipeline.

[0007] The principle and advantages of this scheme are: In existing technologies, traditional sootblowing steam sources mostly rely on high-pressure steam. However, with increasing energy-saving requirements for generating units, the energy consumption contradiction of the original high-pressure steam source for sootblowing is becoming increasingly prominent. At the same time, system adaptability and safety issues occur frequently, affecting the long-term stable operation of the unit. This solution breaks through conventional thinking, focusing on the utilization of low-pressure resteam, and deeply couples low-pressure steam with the sootblowing system. From steam source selection to pipeline and component collaborative design, a unique technical path is formed. Through the designed dual extraction steam points and valve group collaborative control, precise adaptation of multi-condition parameters is achieved, realizing the efficient utilization of low-pressure steam source, thereby solving the problem of excessive energy consumption, while ensuring operational stability and safety.

[0008] This scheme directly obtains steam from the reheater and sets up a low-pressure sootblowing steam source at the low-temperature reheater, eliminating the entire original high-pressure steam source and thus saving the pressure reducing station and desuperheater system. Steam is drawn from both sides of the low-temperature reheater inlet (low-temperature reheater inlet) via connecting pipes, merged, and then directly connected to the sootblowing steam source station after pressure regulation. At high loads, steam is extracted from the low-temperature reheater inlet (or the alternative outlet) as the sootblowing steam source. Analysis shows that this scheme meets the sootblowing steam source requirements, and due to the lower steam parameters at the low-temperature reheater inlet, it is more economical, effectively improving equipment operational reliability, reducing valve failure rates, and minimizing safety hazards.

[0009] Furthermore, the low-temperature reheat inlet includes a low-temperature reheater inlet A and a low-temperature reheater inlet B; the first pipeline is connected to the low-temperature reheater inlet A; and the second pipeline is connected to the low-temperature reheater inlet B. By changing the main extraction point to the low-temperature reheater and prioritizing its use at high loads, the low-temperature reheat inlet steam exhibits stable parameters (pressure and temperature) at high loads, making it more suitable as a soot blowing steam source. Moreover, its low-pressure characteristics effectively reduce energy consumption, thereby replacing the high-pressure steam source and reducing work losses.

[0010] Furthermore, a drainage pipe is also provided on the third pipeline, and a second electric shut-off valve and a manual shut-off valve are provided on the drainage pipe.

[0011] Furthermore, the low re-inlet pressure is 6.3 MPa and the temperature is 361°C. This meets soot blowing requirements while reducing valve operating pressure, improving equipment reliability, minimizing safety hazards, and enhancing boiler operating economy.

[0012] Furthermore, the control pipeline includes a central control terminal, on which a pneumatic regulating valve is connected, and the pneumatic regulating valve is connected to a pneumatic pressure regulating valve.

[0013] Furthermore, the central control terminal is a DCS or PLC. This facilitates the sending of control commands through the central control terminal, improving control flexibility and accuracy.

[0014] Furthermore, the system includes two pipelines connected to the low-pressure re-outlet, which converge at the outlet to form a third pipeline. The low-pressure re-outlet has a pressure of 6.3 MPa and a temperature of 523°C. The outlet steam temperature is also designed to better suit soot blowing requirements, avoiding excessively high inlet steam temperatures and thus improving system flexibility. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model.

[0016] Figure 2 This is a schematic diagram of the control pipeline in this utility model.

[0017] Figure 3 This is a schematic diagram of the original high-pressure steam source soot blowing pipeline structure.

[0018] Figure 4 This is a schematic diagram comparing the structure of the original high-pressure steam source soot blowing pipeline with that of the soot blowing pipeline in this scheme.

[0019] The markings in the accompanying drawings include: First pipeline 1, Second pipeline 2, Third pipeline 3, Low-temperature reheater inlet A end 4, Low-temperature reheater inlet B end 5, Shut-off valve 6, First electric shut-off valve 7, Pneumatic pressure regulating valve 8, Temperature measuring device 9, Control pipeline 10, Pressure transmitter 11, Pneumatic regulating valve 12, Drainage pipeline 13, Second electric shut-off valve 14, Manual shut-off valve 15, Soot blowing air source system 16, Outlet end 17. Detailed Implementation

[0020] The following detailed description illustrates the specific implementation methods: Example 1 This embodiment is basically as shown in the appendix. Figure 1The diagram shows the soot blowing gas source structure for an ultra-supercritical coal-fired turbine generator unit boiler. By introducing a low-pressure soot blowing gas source from a low-pressure reheater, it replaces the high-pressure steam source. After pressure reduction, the gas is directly connected to the soot blowing gas source station, eliminating the need for a desuperheating and pressure reduction system pipeline and reducing the consumption of high-pressure steam. Simultaneously, components such as a shut-off valve, a first electric shut-off valve, and a pneumatic pressure regulating valve control the steam parameters and flow direction to ensure that the soot blowing effect does not decrease, achieving the dual benefits of system economy and safe, stable operation.

[0021] Specifically, the structure of the soot blowing gas source is shown in the attached figure. Figure 1 As shown, it includes a main steam source output from the reheater, a first pipeline 1 and a second pipeline 2 located at the low reheat inlet, and the first pipeline 1 and the second pipeline 2 merge at the outlet end to form a third pipeline 3.

[0022] In this embodiment, the low-temperature reheat inlet includes a low-temperature reheater inlet A end 4 and a low-temperature reheater inlet B end 5. A first pipeline 1 is connected to the connecting pipe of the low-temperature reheater inlet A end 4, and a second pipeline 2 is connected to the connecting pipe of the low-temperature reheater inlet B end 5. At high loads, the low-temperature reheat inlet serves as the primary priority extraction point, drawing steam from both the A and B connecting pipes and merging them into a single stream. At this time, because the parameters of the merged steam are more stable at high loads, it is more suitable as a soot blowing steam source to meet soot blowing requirements, and the low-pressure characteristics also reduce energy consumption.

[0023] Meanwhile, in this embodiment, the low re-outlet can also be used as the second extraction point, or it can be selected as either the low re-inlet or the low re-outlet according to actual usage requirements, so as to improve system flexibility.

[0024] In this embodiment, the first pipeline 1 and the second pipeline 2 are merged at the outlet end to form a third pipeline 3, that is, the steam from the two outlet pipelines is combined into a main pipeline. This concentrates the steam flow and ensures that the amount of steam entering the subsequent regulation stage meets the soot blowing requirements.

[0025] A shut-off valve 6, a first electrically operated shut-off valve 7, and a pneumatic pressure regulating valve 8 are sequentially installed on the third pipeline 3. The shut-off valve 6 allows manual control of the steam flow, and the main pipeline directly controls the steam delivery, improving control convenience while ensuring system safety. The pneumatic pressure regulating valve 8 is installed after the merging pipeline to reduce the steam pressure from the low-pressure reheater to the rated pressure required by the sootblowing system, preventing damage to the sootblower, pipeline, or valves due to excessive pressure. Furthermore, compared to the original high-pressure steam source, its pressure is lower, resulting in less pressure reduction and greater system adaptability. The pneumatic pressure regulating valve 8 is installed after the first electrically operated shut-off valve 7 to prevent steam from flowing back to the low-pressure reheater, avoiding disruption to its normal operation, ensuring stable steam flow and pressure, and reducing the risk of abnormal situations.

[0026] In this embodiment, a temperature measuring device 9 is also installed on the third pipeline 3. The temperature measuring device 9 is installed after the pneumatic pressure regulating valve 8 and before the soot blowing gas source system 16. The temperature measuring device 9 monitors the temperature of the steam entering the soot blowing pipeline in real time to ensure that the temperature is within the allowable range for soot blowing, avoiding excessive temperature that could burn the heated surface, and avoiding excessive temperature that could lead to insufficient soot blowing force, thus ensuring the soot blowing requirements are met and providing data support for operation adjustments.

[0027] In this embodiment, the outlet 17 of the third pipeline 3 is directly connected to the soot blowing gas source system 16. (See attached...) Figure 3 Compared to the pipeline structure using a high-pressure steam source, the pressure reducing station and desuperheater system are directly eliminated, greatly reducing the operating pressure requirements for pressure reduction and cooling, reducing the workload of valves, ensuring that the steam parameters entering the sootblower fully meet the design requirements, and being compatible with the original system. This effectively saves high-grade steam for power generation, improves the economic efficiency of the unit, reduces pressure differential, reduces safety hazards, and improves the reliability of system operation.

[0028] In this embodiment, a control pipeline 10 is also provided on the third pipeline 3, as shown in the attached figure. Figure 2 As shown, the control pipeline 10 includes a central control terminal, which in this embodiment is a DCS or PLC. A pressure transmitter 11 is provided on the central control terminal, and the outlet of the pressure transmitter 11 is connected to the soot blowing gas source system 16. A pneumatic regulating valve 12 is also connected to the central control terminal, and the pneumatic regulating valve 12 is connected to the pneumatic pressure regulating valve 8 of the soot blowing gas source, so as to output control commands to the pressure transmitter 11 or the pneumatic regulating valve 12 through the central control terminal.

[0029] A drainage pipe 13 is also provided on the third pipe 3. A second electric shut-off valve 14 and a manual shut-off valve 15 are provided on the drainage pipe 13 to facilitate control of the drainage pipe.

[0030] The specific implementation process is as follows: Combined with appendix Figure 1 To be continued Figure 2 As shown, steam is extracted from the low-temperature reheater inlet (or alternative outlet) as the soot blowing steam source under high load conditions. In this embodiment, steam extraction from the low-temperature reheater is divided into two schemes: extraction from the low-temperature reheater inlet (including the inlet A and inlet B of the low-temperature reheater) and extraction from the low-temperature reheater outlet (also including ends A and B). In this embodiment, the selection of steam from the inlet or outlet of the low-temperature reheater generally requires the soot blowing steam source pressure to be 2.2~2.6MPa and the superheat to be approximately 80~150℃. The following calculation results are obtained by analyzing and comparing the two schemes respectively.

[0031] Option 1: Extraction from the low re-entry point, with the superheat calculation table as follows.

[0032] Option 2: Extraction from the low re-exit, the superheat calculation table is as follows.

[0033] The calculation data above shows that, based on the superheat calculation and analysis of the reduced pressure, both the low re-inlet and low re-outlet can meet the requirements for soot blowing steam source. Since the low re-inlet steam parameters are lower and more economical, extracting steam from the low re-inlet as the soot blowing steam source is more effective; therefore, the low re-inlet is the preferred choice.

[0034] Based on the assumption that the boiler undergoes normal soot blowing once a day, and excluding external factors such as denitrification catalyst and air preheater soot blowing, the daily savings are calculated to be 0.3109668 t / day of standard coal; the daily additional power generation is 1070.42767 kW·h / day. The detailed calculation table is as follows:

[0035] In this embodiment, combined with the appendix Figure 3 The original high-pressure steam source pipeline structure shown in the diagram uses steam from the high-pressure inlet pipe for boiler soot blowing. The steam temperature and pressure are relatively high, requiring significant temperature and pressure reduction before it can be used for soot blowing. This proposed solution directly utilizes the reheater's steam source, drawing steam from the connecting pipes on both sides of the low-temperature reheater's inlet or outlet, directly replacing the entire original high-pressure steam source, as shown in the attached diagram. Figure 4 As shown, a new low-pressure sootblowing steam source path is constructed, thereby eliminating the need for a pressure reducing station and desuperheater system, allowing direct use in the sootblowing system. This also reduces the operating pressure of related valves, extends valve lifespan, improves energy efficiency, and enhances overall power generation efficiency. Furthermore, a dual extraction point is set at the low-pressure reheat inlet and outlet, allowing for flexible switching according to different operating conditions such as high load, adapting to steam parameter requirements and broadening the adaptability range of the sootblowing system. In this scheme, pipelines are drawn from both sides of the low-pressure reheat station, merged, and connected to the original sootblowing pipeline, forming a steam delivery channel for extraction, merging, adaptation, and connection. Simultaneously, a shut-off valve (controlling the main circuit's on / off state), a pressure reducing valve (regulating steam pressure to adapt to the system), a check valve (preventing steam backflow), and temperature measuring points (monitoring steam temperature) are installed to ensure the independent and stable operation of the low-pressure reheat and sootblowing systems, guaranteeing stable steam parameters and system safety.

[0036] Previously, when the high-pressure steam source was used for soot blowing, the high-pressure steam, which could have contributed to power generation, was only used for soot blowing, resulting in energy waste. Furthermore, the high-pressure steam source parameters were poorly matched with the soot blowing system's requirements, potentially damaging equipment due to excessive pressure or affecting soot blowing performance due to unstable parameters. This solution uses low-temperature reheater steam, releasing the power potential of high-pressure steam, improving unit energy utilization efficiency, reducing high-pressure steam consumption, and directly reducing energy losses on the power generation side. In long-term operation, this significantly improves unit power generation efficiency and increases revenue. Moreover, through precise control via pressure reducing valves and temperature measuring points, the steam source parameter matching problem is solved, resulting in more stable soot blowing performance.

[0037] The above descriptions are merely embodiments of this utility model. Commonly known technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solution of this utility model. These modifications and improvements should also be considered within the scope of protection of this utility model, and will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A soot blowing gas source structure for a coal-fired steam turbine generator unit with ultra-supercritical parameters, characterized in that: It includes a main steam source output from the reheater, a first pipeline and a second pipeline located at the low reheat inlet, the pressure of the low reheat inlet is 6.3 MPa and the temperature is 361°C, the low reheat inlet includes a low-temperature reheater inlet A end and a low-temperature reheater inlet B end; the first pipeline is connected to the low-temperature reheater inlet A end; The second pipeline is connected to the inlet B end of the low-temperature reheater; the first and second pipelines merge at the outlet end to form a third pipeline, on which a shut-off valve, a first electric shut-off valve, and a pneumatic pressure regulating valve are sequentially installed; a temperature measuring device is also installed on the third pipeline; the outlet end of the third pipeline is directly connected to the soot blowing steam source station, so that steam is drawn from the connecting pipes on both sides of the low-temperature reheater inlet or outlet, eliminating the need for a pressure reducing station and a desuperheater system, and can be directly used for the soot blowing system; a control pipeline is also installed on the third pipeline, and a pressure transmitter is installed on the control pipeline, the outlet end of which is connected to the soot blowing steam source station pipeline.

2. The soot blowing gas source structure for an ultra-supercritical parameter coal-fired steam turbine generator set boiler as described in claim 1, characterized in that: A drainage pipe is also provided on the third pipeline, and a second electric shut-off valve and a manual shut-off valve are provided on the drainage pipe.

3. The soot blowing gas source structure for an ultra-supercritical parameter coal-fired steam turbine generator set boiler as described in claim 1, characterized in that: The control pipeline includes a main control terminal, on which a pneumatic regulating valve is connected, and the pneumatic regulating valve is connected to a pneumatic pressure regulating valve.

4. The soot blowing gas source structure for an ultra-supercritical parameter coal-fired steam turbine generator set boiler according to claim 3, characterized in that: The central control terminal is either a DCS or a PLC.

5. The soot blowing gas source structure for an ultra-supercritical parameter coal-fired steam turbine generator set boiler according to claim 1, characterized in that: It also includes setting up two pipelines from the low outlet, which merge into a third pipeline at the outlet end.

6. The soot blowing gas source structure for an ultra-supercritical parameter coal-fired steam turbine generator set boiler according to claim 5, characterized in that: The pressure at the low re-outlet is 6.3 MPa, and the temperature is 523°C.

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