Concentrated gas supply construction method and system for unit boiler construction

Abstract

The invention discloses a unit boiler construction centralized gas supply construction method and system, and relates to the technical field of building engineering construction auxiliary equipment.The method comprises the steps that a first gas supply source and a second gas supply source are arranged in a boiler bottom layer area in a centralized mode; constructing a conveying network extending to each operation layer along the height of the boiler, wherein the conveying network comprises an ascending pipeline and a branch pipeline; a pressure regulation and control assembly comprising a first-stage regulation and control unit and a second-stage regulation and control unit is arranged to control the medium pressure of the tail ends of the rising pipeline and the branch pipeline; gas using terminals are arranged at the tail ends of branch pipelines of all operation layers. The system comprises a first gas supply station, a second gas supply station, a rising vertical pipe, seamless steel pipe branch pipes, the gas using terminals and a pressure regulation and control system. According to the invention, the problems of low efficiency, large potential safety hazard and serious resource waste of an existing dispersed gas supply mode are effectively solved through centralized arrangement of gas sources, construction of a pipeline conveying network and setting of graded pressure regulation and control, and efficient, stable and safe conveying of industrial fuel gas in a high-altitude operation scene is realized.

Description

Technical Field

[0001] This invention relates to the field of construction auxiliary equipment technology, specifically to a fluid conveying system for large boiler installation projects, and more particularly to a centralized gas supply construction method and system suitable for high-altitude operations of 1000MW and above ultra-supercritical boiler units. Background Technology

[0002] As thermal power generating units are upgraded towards larger capacity and higher parameters, especially with the popularization of 1000MW and above ultra-supercritical units, the installation height of boilers has generally exceeded 100 meters. During the peak period of boiler installation, a large number of hot processing operations such as splicing and cutting steel plates are involved, which consume a huge amount of industrial fuels such as oxygen and acetylene, and are highly dependent on the continuity and stability of the gas supply.

[0003] Currently, in this type of installation and construction field, the industry generally adopts a decentralized gas cylinder supply mode. This mode mainly uses construction elevators to vertically transport full gas cylinders to each working platform for construction workers to use as needed. However, with the increase in boiler height and the intensity of work, the drawbacks of this traditional mode are becoming increasingly apparent:

[0004] 1. Gas cylinders are consumed quickly. Due to the limited vertical transportation conditions at the construction site, it takes a long time to transport gas cylinders from the ground to the 100-meter working level. Frequent replacement of gas cylinders not only seriously disrupts the construction rhythm, but also requires a large amount of manpower for handling, resulting in high labor costs.

[0005] 2. A large number of gas cylinders are scattered on narrow work platforms and passages on various floors. On the one hand, this seriously occupies the limited construction space and obstructs personnel passage. On the other hand, the gas cylinders are at risk of tipping over or falling from a height in the high-altitude environment. Moreover, it is difficult to achieve unified fire prevention and explosion prevention supervision when multiple gas cylinders are scattered, and the risk of leakage causing fire or explosion is relatively large.

[0006] 3. In single-cylinder gas supply mode, as the pressure inside the cylinder decreases, the output pressure fluctuates significantly, which can easily lead to unstable flame and directly affect the cutting and welding quality. In addition, in order to avoid work interruption, workers often replace the gas cylinder when a high proportion of gas remains inside, resulting in a large amount of residual gas not being fully utilized, causing resource waste and a significant increase in gas costs.

[0007] 4. A few projects have attempted to use simplified pipeline transportation methods to replace gas cylinder handling, but the existing solutions are mostly temporary and simplistic arrangements, without systematic design for the special characteristics of ultra-high-rise and ultra-multi-story building construction. In particular, there are obvious deficiencies in multi-level pressure control to ensure remote pressure stability, pipeline route planning in complex steel structure environments to avoid formal equipment and high-temperature areas, and multi-level backfire prevention safety protection for flammable and explosive gases such as acetylene. These deficiencies make it difficult to meet the comprehensive requirements of high efficiency and safety for the installation of large-scale unit boilers.

[0008] Therefore, how to provide a centralized gas supply device that can significantly improve gas supply efficiency, ensure the safety of high-altitude operations, and reduce resource consumption for the installation of ultra-high and multi-story boilers at the hundred-meter level has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0009] In response to the problems mentioned in the background art regarding the existing decentralized gas supply mode, such as low gas supply efficiency, significant safety hazards, unstable gas supply quality, and lack of systematic design in existing improvement schemes, this invention provides a centralized gas supply construction method and system for boiler construction. By centrally arranging the gas source at the bottom layer, constructing a transmission network extending along the height of the boiler, and setting up a graded pressure control system, efficient, stable, and safe transmission of industrial gas is achieved in high-altitude operation scenarios.

[0010] To achieve the above objectives, the present invention provides the following technical solution:

[0011] Firstly, in terms of method, this invention provides a method for centralized gas supply construction of a boiler unit, comprising the following steps:

[0012] Provide a first gas supply source and a second gas supply source, and arrange the first gas supply source and the second gas supply source in the bottom area of ​​the boiler;

[0013] A conveying network is constructed that extends from the bottom area along the height of the boiler to each working layer. The conveying network includes at least one rising pipeline and several branch pipelines that are connected to the rising pipeline and distributed in each working layer.

[0014] A pressure regulation component is provided in the conveying network. The pressure regulation component includes a primary regulation unit and a secondary regulation unit. The primary regulation unit controls the medium pressure in the riser pipeline to be within a first preset range. The secondary regulation unit is located at the end of the branch pipeline of each working layer to adjust the medium pressure to a second preset range.

[0015] Gas terminals are installed at the end of the branch pipelines at each working level to connect the construction tools to the delivery network.

[0016] As a further limitation of the method, before constructing the conveying network, a path planning step is also included: based on a three-dimensional model of the boiler structure, the laying path of the riser pipe and branch pipes is simulated to avoid the boiler body structure and the preset permanent equipment installation area.

[0017] As a further limitation of the method, the step of constructing the delivery network specifically includes:

[0018] The riser pipe is laid along the boiler steel frame column and fixed at intervals by fixing components.

[0019] The branch pipeline is laid along the bottom of the beam of the working platform.

[0020] As a further limitation of the method, after the construction of the transport network is completed, a pressure testing step is also included: applying test pressure to the transport network and maintaining the pressure, and monitoring whether the pressure drop is within the allowable threshold.

[0021] As a specific application of the method, the first gas source is an oxygen source and the second gas source is an acetylene source. When constructing the delivery network, the riser pipes corresponding to the oxygen source and the riser pipes corresponding to the acetylene source are laid on different sides of the boiler.

[0022] Secondly, in terms of the system, the present invention also provides a centralized gas supply system for boiler construction to implement the above method. The system includes: a first gas supply station, a second gas supply station, a riser, a seamless steel pipe branch, a gas terminal, and a pressure control system.

[0023] The first gas supply station is at least one unit, which is located at the bottom of the boiler to centrally store the first gas medium;

[0024] At least one second gas supply station is provided, which is located at the bottom of the boiler and maintains a safe distance from the first gas supply station, so as to centrally store the second gas medium;

[0025] The riser is provided with at least two sets, including: a first riser connected to the first gas supply station and a second riser connected to the second gas supply station, wherein the first riser and the second riser extend along the height direction of the boiler.

[0026] The seamless steel pipe branch pipe is provided in several parts, which are distributed in each working layer of the boiler and are connected to the corresponding rising riser pipe respectively.

[0027] The gas terminal is provided in several units, which are located at the end of the seamless steel pipe branch pipe of each working layer;

[0028] The pressure control system includes a primary pressure reducing valve assembly located at the outlet of the gas supply station and a secondary pressure reducing valve assembly located at the gas consumption terminal.

[0029] As a further definition of the system, the first gas supply station is an oxygen station, which has at least two sets of parallel gas supply headers to connect multiple oxygen cylinder groups to achieve alternating gas supply; the second gas supply station is an acetylene station, which has at least two sets of parallel gas supply headers to connect multiple acetylene cylinder groups.

[0030] As a further definition of the system, the acetylene station and its connected delivery path are equipped with a multi-stage backfire prevention device. Specifically, the multi-stage backfire prevention device includes a first-stage backfire prevention device installed at the outlet of the acetylene station, a second-stage backfire prevention device installed at the connection between the riser and the branch pipeline, and a third-stage backfire prevention device installed at the gas terminal inlet.

[0031] As a further definition of the system, the gas terminal includes a buffer gas storage container, which is provided with multiple valve interfaces, and the valve interfaces are connected to the gas pipes of construction tools through quick connectors.

[0032] As a preferred technical solution for the system, anti-static grounding devices are provided at intervals on the rising riser and seamless steel pipe branch pipe, and the grounding resistance of the anti-static grounding device is not higher than a preset threshold.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1. By centrally storing gas cylinders at the bottom floor and transporting them through a pipeline network, the waiting time for vertical transportation of gas cylinders is eliminated, realizing a continuous gas supply mode that can be used immediately. Furthermore, the parallel design of the dual main pipes ensures uninterrupted gas supply during cylinder switching, significantly improving the construction pace.

[0035] 2. The gas source is centrally managed in a dedicated gas supply room on the ground floor, which fundamentally eliminates the physical risk of gas cylinders tipping over or falling from high-altitude work surfaces. In addition, the three-level backfire prevention device for the acetylene system and the anti-static grounding system laid throughout the pipeline network have constructed a multi-level, three-dimensional safety protection system, effectively preventing major safety hazards such as fires and explosions.

[0036] 3. Through a two-stage pressure reduction mode of centralized control at the primary level and terminal regulation at the secondary level, the pressure at remote gas consumption points is kept stable, improving the process quality of cutting and welding. At the same time, the centralized gas supply mode can make full use of the residual gas in the cylinders, reducing resource waste and gas costs caused by frequent cylinder replacements.

[0037] 4. The pipelines are laid in a standardized manner along the boiler steel frame and the bottom of the beams. There are no gas cylinders piled up on the work surface, the passage is unobstructed, and the cleanliness of the construction environment is greatly improved. Combined with CAD three-dimensional path planning, permanent equipment is effectively avoided, avoiding later dismantling and modification.

[0038] In summary, this invention effectively solves the gas supply problem in ultra-high and ultra-multi-story boiler installation scenarios through systematic structural design and methodological innovation. It combines high efficiency, safety, economy and environmental protection, and has application value. Attached Figure Description

[0039] Figure 1This is a process flow diagram of a centralized gas supply construction method for a boiler unit according to the present invention.

[0040] Figure 2 This is a schematic diagram of the oxygen and acetylene pipeline layout at the 88-meter level of the boiler in one embodiment of the present invention.

[0041] Figure 3 This is a schematic diagram of the overall layout structure of the oxygen and acetylene working layers of the boiler in one embodiment of the present invention.

[0042] Explanation of reference numerals in the attached diagram: 1. Oxygen riser main pipe; 2. Acetylene riser main pipe; 3. First oxygen terminal; 4. First acetylene terminal; 5. Second oxygen terminal; 6. Second acetylene terminal; 7. Oxygen station; 8. Acetylene station; 9. Rising riser; 10. Seamless steel pipe branch pipe. Detailed Implementation

[0043] To enhance understanding of the present invention, the invention will be further described in detail below with reference to embodiments and accompanying drawings. These embodiments are only for explaining the invention and do not constitute a limitation on the scope of protection of the invention.

[0044] like Figure 1 As shown in the figure, the centralized gas supply construction method for unit boiler construction provided in this embodiment includes the following specific implementation steps:

[0045] Step 1 Construction Preparation: First, plan and construct a dedicated gas supply room in the bottom area of ​​the boiler (usually the 0-meter level). Determine the location and quantity of gas supply points on each working level according to the construction drawings. Prepare the necessary materials, including seamless steel pipes, valves, pressure reducing valves, quick connectors, etc. At the same time, ensure that the gas supply room is well ventilated and that flammable and explosive materials are strictly prohibited from being piled up within 5 meters of the surrounding area.

[0046] Step 2: 3D Path Simulation: Before formal installation, path planning is performed based on a 3D model of the boiler structure. CAD software is used to simulate the laying paths of the riser and branch pipes to avoid the boiler steel frame, existing equipment piping, and high-temperature areas. Figure 3 As shown, the oxygen riser 1 and acetylene riser 2 are determined to rise along the steel frame columns on different sides of the boiler, and branch interfaces are reserved at each working level. This step can effectively avoid collisions with permanent equipment in the later stage and reduce rework.

[0047] Step 3: Pipe Prefabrication and Inspection: Based on the simulation results, pipes are prefabricated. Mechanical cutting is used to ensure the perpendicularity of the cut. Elbows are formed using a special mold, with a uniform radius of curvature of 1.5 times the pipe diameter to reduce resistance. Pipe joints are welded using argon arc welding with H08Mn2SiA welding wire. The welding current is controlled between 80-120A. All welds must undergo 100% X-ray non-destructive testing to ensure that the weld quality meets the NB / T47013 standard.

[0048] Step 4: On-site installation: such as Figure 3 As shown, the riser 9 is laid along the boiler steel frame column and fixed at intervals by fixing components. The spacing between fixing points is no more than 3 meters. At each working level, seamless steel pipe branch pipe 10 is led out from the riser 9 and laid along the bottom of the platform beam to the preset gas consumption point. During the installation process, the oxygen pipeline surface is painted with sky blue paint and the acetylene pipeline surface is painted with white paint, and the medium flow direction is marked.

[0049] Step 5 Pressure Test: After the pipeline is installed, a water pressure test is carried out. The oxygen pipeline is pressurized to 1.5 times the design pressure, and the acetylene pipeline is pressurized to the corresponding pressure. The pressure is maintained for 24 hours, and the pressure drop is monitored to see if it is within the allowable threshold. After the test is passed, clean compressed air is used to purge the water in the pipeline and nitrogen is used to replace it until the oxygen content of the discharged gas is lower than the safety standard.

[0050] Step 6 System Debugging: Start the gas supply system, adjust the medium pressure in the riser pipeline to the first preset range through the primary control unit, and then adjust the pressure to the second preset range at the end of the branch pipeline of each working layer through the secondary control unit. Then perform a linkage test to simulate the gas cylinder switching process and ensure that there is no sudden drop in pressure when the dual main pipelines are supplying gas.

[0051] Step 7 Acceptance and Delivery: Conduct a comprehensive inspection of the system, including pipe fixing, labeling, grounding, etc., and conduct actual gas supply tests. After confirming that the pressure of each gas terminal is stable and there are no leaks, compile welding records, test reports and other documents, and deliver the system for use.

[0052] like Figure 2 and Figure 3 As shown in the figure, this embodiment provides a centralized gas supply system for boiler construction, including an oxygen station 7 and an acetylene station 8 located at the bottom of the boiler.

[0053] Oxygen station 7 and acetylene station 8 maintain a safe distance from each other, and each has at least two sets of parallel gas supply headers to connect multiple gas cylinder groups to achieve alternating gas supply.

[0054] The first riser pipe is connected from oxygen station 7 and the second riser pipe is connected from acetylene station 8. The two riser pipes extend vertically upward along the steel frame columns on different sides of the boiler to the top of the furnace, forming riser pipe 9.

[0055] Seamless steel pipe branch pipes 10 are led out from the riser pipe 9 on each working level and distributed along the bottom of the beam to each gas consumption point.

[0056] A gas terminal is installed at the end of the branch pipe, and the gas terminal includes a buffer gas storage container, such as... Figure 2 The first oxygen terminal 3, the first acetylene terminal 4, the second oxygen terminal 5, and the second acetylene terminal 6 are equipped with multiple valve interfaces on the buffer gas storage container, which are connected to the gas pipes of the construction tools through quick connectors.

[0057] The pressure control system includes a primary pressure reducing valve group and a secondary pressure reducing valve group: the primary pressure reducing valve group is installed at the outlet of oxygen station 7 and acetylene station 8 to reduce the outlet pressure of the gas cylinders to the main pipeline delivery pressure; the secondary pressure reducing valve group is installed at the gas consumption terminal of each working layer to precisely adjust the main pipeline pressure to the working pressure required for construction.

[0058] To ensure safety, this system is equipped with a three-stage backfire prevention device along the acetylene delivery path: the first-stage backfire prevention device is installed at the outlet of acetylene station 8; the second-stage backfire prevention device is installed at the connection between the riser 9 and the seamless steel pipe branch 10; and the third-stage backfire prevention device is installed at the inlet of the gas terminal.

[0059] In addition, an anti-static grounding device is installed every 30 meters in the entire pipeline system. It is reliably connected to the grounding electrode using 40×4mm galvanized flat steel to ensure that the grounding resistance does not exceed the preset threshold.

[0060] In actual construction, the diameter of the riser pipe 9 and the diameter of the branch pipes can be adjusted according to the boiler height and gas consumption.

[0061] During the pressure test, the pressure value of the water pressure test can be dynamically adjusted according to the design pressure, but it must be ensured to be no less than 1.5 times the design pressure.

[0062] During nitrogen replacement, the oxygen concentration at the emission outlet must be continuously monitored, and acetylene can only be introduced after it is ensured to be below 3%.

[0063] Implementation Example

[0064] Taking a 2×1,000 MW unit expansion project as an example, the feasibility and application effect of the centralized gas supply construction method and system described in this invention are explained.

[0065] The project plans to construct two 1000MW ultra-supercritical double reheat coal-fired power generating units. The boiler is an ultra-supercritical parameter tower boiler with a height of 122 meters and 11 working platforms. During the peak period of boiler installation, the daily consumption of oxygen and acetylene is about 80 bottles. It involves a large number of hot processing operations such as splicing and cutting, and steel plate cutting, which requires extremely high continuity and stability of gas supply.

[0066] In this project, the construction party adopted the centralized gas supply construction method and system provided by the present invention, and the specific implementation is as follows: oxygen station 7 and acetylene station 8 are set up at the 0-meter level of the boiler, with a distance of more than 10 meters between the two stations. Each station is equipped with two sets of parallel gas supply main pipes, and each set can connect 10 gas cylinders to achieve uninterrupted alternating gas supply.

[0067] Through CAD 3D simulation, the laying path of the rising riser 9 was planned, so that it rises vertically along the steel frame columns on both sides of the boiler, and seamless steel pipe branch pipe 10 is led out at the key working layer, with 4 gas terminals set at each layer.

[0068] In terms of pressure control, a primary pressure reducing valve group is used to stabilize the pressure of the oxygen main pipe at 0.6MPa and the pressure of the acetylene main pipe at 0.12MPa. Then, the pressure is precisely adjusted to the required values ​​for construction (0.5MPa for oxygen and 0.1MPa for acetylene) through the secondary pressure reducing valve groups at each terminal.

[0069] In terms of safety protection, the acetylene system is equipped with a three-level backfire prevention device, and anti-static grounding points are set every 30 meters along the entire pipeline, with the grounding resistance controlled within 10Ω.

[0070] The project has yielded the following significant results:

[0071] Gas supply efficiency has been greatly improved: gas cylinders are centrally stored on the ground floor, eliminating the need to wait for vertical transport by elevator. The time for changing gas cylinders has been reduced by more than 50%, enabling continuous gas supply that can be used immediately. The time spent using construction elevators has been reduced by 40%, effectively ensuring the construction schedule.

[0072] Safety performance is significantly enhanced: there are no gas cylinders stacked on the high-altitude work surface, eliminating the risk of tipping and falling. The three-level backfire prevention device and the anti-static grounding system work together to ensure the absolute safety of acetylene transportation. No leakage or fire incidents occurred during the entire construction period.

[0073] Both gas supply quality and resource utilization are improved: the two-stage pressure reduction system ensures stable remote pressure and flame stability, significantly improving the first-pass yield of welding. The centralized gas supply mode increases the utilization rate of residual gas in gas cylinders to over 95%, reducing gas costs.

[0074] Improved level of civilized construction: Pipelines are laid in a standardized manner along the steel frame, the work surface is clean and unobstructed, and the site has won the title of demonstration area for safe and civilized construction.

[0075] The successful implementation of this project demonstrates that the centralized gas supply construction method and system provided by this invention can adapt to the high-altitude, multi-level, and confined space construction environment of 1000MW ultra-supercritical unit boilers, and has significant economic and social benefits, providing a reliable solution for similar projects.

[0076] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for centralized gas supply construction during boiler construction, characterized in that, Includes the following steps: Provide a first gas supply source and a second gas supply source, and arrange the first gas supply source and the second gas supply source in the bottom area of ​​the boiler; A conveying network is constructed that extends from the bottom area along the height of the boiler to each working layer. The conveying network includes: at least one rising pipeline and several branch pipelines connected to the rising pipeline and distributed in each working layer. A pressure regulation component is provided in the conveying network. The pressure regulation component includes a primary regulation unit and a secondary regulation unit. The primary regulation unit controls the medium pressure in the riser pipeline to be within a first preset range. The secondary regulation unit is located at the end of the branch pipeline of each working layer to adjust the medium pressure to a second preset range. Gas terminals are installed at the end of the branch pipelines at each working level to connect the construction tools to the delivery network.

2. The centralized gas supply construction method for unit boiler construction according to claim 1, characterized in that, Before constructing the transmission network, a path planning step is also included: based on a three-dimensional model of the boiler structure, the laying path of the riser pipe and branch pipes is simulated to avoid the boiler body structure and the preset permanent equipment installation area.

3. The centralized gas supply construction method for unit boiler construction according to claim 1, characterized in that, The step of constructing the delivery network further includes: The riser pipe is laid along the boiler steel frame column and fixed at intervals by fixing components. The branch pipeline is laid along the bottom of the beam of the working platform.

4. The centralized gas supply construction method for unit boiler construction according to claim 1, characterized in that, After the delivery network is constructed, a pressure test step is also included: applying test pressure to the delivery network and maintaining the pressure, and monitoring whether the pressure drop is within the allowable threshold.

5. The centralized gas supply construction method for unit boiler construction according to claim 1, characterized in that, The first gas source is an oxygen source, and the second gas source is an acetylene source; When constructing the delivery network, the riser pipes corresponding to the oxygen source and the riser pipes corresponding to the acetylene source are laid on different sides of the boiler.

6. A centralized gas supply system for boiler construction, characterized in that, include: First gas supply station, second gas supply station, riser pipe, seamless steel pipe branch pipe, gas terminal and pressure control system; The first gas supply station shall be at least one, which shall be located at the bottom of the boiler to centrally store the first gas medium; At least one second gas supply station is provided, which is located at the bottom of the boiler and maintains a safe distance from the first gas supply station, so as to centrally store the second gas medium; The riser is provided in at least two sets, including a first riser connected to the first gas supply station and a second riser connected to the second gas supply station. The first riser and the second riser extend along the height direction of the boiler. The seamless steel pipe branch pipe is provided in several parts, which are distributed in each working layer of the boiler and are connected to the corresponding rising riser pipe respectively. The gas terminal is provided in several units, which are located at the end of the seamless steel pipe branch pipe of each working layer; The pressure control system includes a primary pressure reducing valve assembly located at the outlet of the gas supply station and a secondary pressure reducing valve assembly located at the gas consumption terminal.

7. The centralized gas supply system for boiler construction according to claim 6, characterized in that, The first gas supply station is an oxygen station, which is equipped with at least two sets of parallel gas supply headers to connect multiple oxygen cylinder groups to achieve alternating gas supply. The second gas supply station is an acetylene station, which has at least two sets of parallel gas supply headers to connect multiple acetylene cylinder groups.

8. The centralized gas supply system for boiler construction according to claim 7, characterized in that, The acetylene station and its connected transport path are equipped with multi-stage backfire prevention devices. The multi-stage backfire prevention device includes a first-stage backfire prevention device installed at the outlet of the acetylene station, a second-stage backfire prevention device installed at the connection between the riser and the branch pipeline, and a third-stage backfire prevention device installed at the inlet of the gas terminal.

9. The centralized gas supply system for boiler construction according to claim 6, characterized in that, The gas terminal includes a buffer gas storage container; The buffer gas storage container is equipped with multiple valve ports, which are connected to the gas pipes of construction tools via quick connectors.

10. The centralized gas supply system for boiler construction according to claim 6, characterized in that, The rising riser and seamless steel pipe branch pipe are equipped with anti-static grounding devices at intervals, and the grounding resistance of the anti-static grounding devices is not higher than a preset threshold.

Images