A dust removal method for nuclear power plant construction site

Abstract

A dust removal method for nuclear power plant construction sites includes the following steps: dividing the construction site into off-site and on-site workshops, installing a dust removal system in the on-site workshops; dividing construction work items into essential on-site and non-essential on-site items, with non-essential on-site items completed in the off-site workshops. Essential on-site items are further divided into in-situ and non-in-situ items, with non-in-situ items completed in a centralized grinding and welding shed. A decentralized dust purification system is deployed for the workstations of the in-situ projects; and dust collected by the centralized grinding and welding shed and at least part of the decentralized dust purification system is discharged outdoors via a temporary exhaust system. This method can effectively reduce dust pollution at nuclear power plant construction sites and improve the construction work environment and ergonomics.

Description

Technical Field

[0001] The invention belongs to the field of nuclear power, and in particular relates to a dust removal method at a nuclear power plant construction site. Background Art

[0002] Nuclear power plant construction involves extensive construction and a long construction period. This is especially true for new units like the CAP1000, which utilize compact, modular plant layouts. Ventilation equipment is often installed on the highest floors, preventing the formal ventilation system from being operational during the early stages of construction. This results in poor air quality and severe dust pollution within the nuclear island buildings during construction. This negatively impacts the health of construction workers and the protection of finished equipment. Therefore, developing a dust removal method for nuclear power plant construction sites is crucial for improving the construction environment, protecting equipment, and safeguarding the health of workers. Summary of the Invention

[0003] The purpose of the present invention is to provide a dust removal method for a nuclear power plant construction site, which can reduce dust pollution at the construction site before the formal ventilation system is put into use.

[0004] According to an embodiment of the present invention, a method for dust removal at a nuclear power plant construction site is provided, the method comprising the following steps:

[0005] Step a): Divide the construction site into off-site workshops and on-site workshops.

[0006] The off-site workshop is located outside the nuclear island and includes one or more of a piping workshop, a main system workshop, an electrical and instrumentation workshop, a ventilation workshop, and a sandblasting and painting workshop;

[0007] The on-site workshop is arranged in the nuclear island and is provided with a dust removal system, which includes one or more centralized grinding and welding work sheds, a decentralized fume purification system and a temporary exhaust system;

[0008] Step b): Dividing the construction work items into necessary on-site items and non-essential on-site items, wherein the necessary on-site items must be carried out at the workstations in the on-site workshop, and the non-essential on-site items may not be carried out at the workstations in the on-site workshop;

[0009] Arrange the non-essential projects on site to be implemented in the off-site workshop;

[0010] Dividing the necessary projects on the site into on-site projects and non-in-situ projects, wherein the on-site projects must be completed on-site at a given workstation, and the non-in-situ projects can be completed at a non-given workstation, arranging the non-in-situ projects for implementation in the centralized grinding and welding work shed, installing the decentralized fume purification system at the workstation of the on-site projects, and connecting the centralized grinding and welding work shed and at least part of the decentralized fume purification system to the outdoors through the temporary exhaust system to discharge the fume generated by the operation to the outdoors;

[0011] Step c): starting the dust removal system and executing the construction work project.

[0012] This method allows for centralized dust-generating operations like grinding and welding to be handled within a closed work shed, preventing large amounts of dust from contaminating the construction site. Furthermore, by implementing a decentralized dust purification system, dust removal can be performed for construction projects that cannot be centralized within a closed work shed. This system can effectively improve the construction environment within the nuclear island of a nuclear power plant, reduce dust pollution, enhance on-site ergonomics, and protect on-site equipment.

[0013] Furthermore, in some embodiments, the centralized grinding and welding work shed is configured as a closed work shed, and a plurality of grinding stations and welding stations are arranged in the centralized grinding and welding work shed, each of which is provided with a negative pressure dust collection device, and the negative pressure dust collection device is connected to the temporary exhaust system to collect and discharge the dust generated by the grinding station and the welding station. The decentralized fume purification system is arranged at multiple stations outside the centralized grinding and welding work shed, and includes a plurality of self-priming grinding tools and / or a plurality of welding fume exhaust devices, at least some of which are connected to the temporary exhaust system to collect and discharge the generated dust; the self-priming grinding tools and the welding fume exhaust devices that are not connected to the temporary exhaust system are provided with dust collection bags for collecting dust.

[0014] Furthermore, in some embodiments, the centralized grinding and welding work shed is configured as a negative pressure working environment. The negative pressure environment can further reduce the risk of dust escape.

[0015] Furthermore, in some embodiments, the centralized grinding and welding work shed is equipped with a fan and is connected to the temporary exhaust system through the fan.

[0016] Furthermore, in some embodiments, the air volume of the fan satisfies the requirement that the ventilation volume in the centralized grinding and welding work shed reaches at least 4 times per hour.

[0017] Furthermore, in some embodiments, the centralized grinding and welding work shed is made of aluminum plates or steel plates, and sealant is provided at the joint gaps.

[0018] Furthermore, in some embodiments, the pipes of the temporary exhaust system are made of galvanized steel plates or soft air ducts.

[0019] Furthermore, in some embodiments, the self-priming grinding tool and the welding fume exhaust device are configured as a modular device.

[0020] Furthermore, in some embodiments, the method also includes the step of controlling the humidity at the construction site using a dehumidifier.

[0021] Furthermore, in some embodiments, the step c) further includes the step of performing thermal dust removal operations in the on-site workshop at certain time intervals. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a structural diagram of a centralized grinding and welding work shed in one embodiment;

[0023] Figure 2 1 is a flow chart of a dust removal method at a nuclear power plant construction site according to one embodiment.

[0024] The purpose of the above-mentioned drawings is to provide a detailed explanation of the present invention so that those skilled in the art can understand the technical concepts of the present invention, and is not intended to limit the present invention. For the sake of simplicity, some of the above-mentioned drawings only schematically depict structures related to the technical features of the present invention and do not strictly depict the complete structure and all details according to actual scale. DETAILED DESCRIPTION

[0025] The present invention will be further described in detail below through specific embodiments with reference to the accompanying drawings.

[0026] References to "embodiments" herein mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment herein. The appearance of such phrases in various places in the specification does not necessarily refer to the same embodiment, nor does it limit mutually exclusive independent or alternative embodiments. Those skilled in the art will appreciate that an embodiment herein may be combined with other embodiments as long as no structural conflicts arise.

[0027] In the description of this document, unless otherwise clearly specified and limited, the technical terms "install", "connect", "connect", etc. should be understood in a broad sense. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of this application can be understood according to specific circumstances.

[0028] In the description of this document, terms indicating orientation or positional relationships, such as "up", "down", "left", "right", "horizontal", "vertical", "height", "length", and "width", are intended to accurately describe the embodiments and simplify the description, but are not intended to limit the parts or structures involved to having a specific orientation, being installed or operated in a specific orientation, and should not be understood as limiting the embodiments in this document.

[0029] In the description herein, terms such as "first" and "second" are used only to distinguish different objects and should not be understood to indicate relative importance or to limit the quantity, specific order, or primary and secondary relationship of the described technical features. In the description herein, "plurality" means at least two.

[0030] The CAP1000 reactor nuclear power unit features a compact plant layout and utilizes modular construction, with civil engineering and installation work carried out in parallel. This results in a long construction cycle. Ventilation equipment for the CAP1000 reactor is typically located on the top floor of the building, so formal ventilation equipment is unavailable for extended periods during construction. This results in poor air quality within the nuclear island and severe dust pollution from grinding and welding operations, hindering ergonomics and protecting finished equipment.

[0031] In order to solve the above problems, an embodiment of one aspect of the present invention provides a dust removal method for a nuclear power plant construction site, which can be used to reduce dust pollution at the construction site and improve the working environment before the formal ventilation system is put into use.

[0032] The process of this method is as follows Figure 2 As shown, the following steps are included:

[0033] Step a): First, divide the construction site into off-site workshops and on-site workshops. The off-site workshops are located outside the nuclear island, while the on-site workshops are located inside the nuclear island buildings. Depending on the specific construction project, site environment, and production capacity requirements, the off-site workshops may include one or more of the following: piping workshop, main system workshop, electrical and instrumentation workshop, ventilation workshop, and sandblasting and painting workshop. The off-site workshops are located outside the nuclear island buildings to facilitate the installation of independent dust removal and purification equipment. The on-site workshops are equipped with a dust removal system, which specifically includes a centralized grinding and welding shed, a decentralized fume purification system, and a temporary exhaust system.

[0034] In a preferred embodiment, the centralized grinding and welding work shed adopts a closed work shed, which is equipped with multiple grinding stations and welding stations to allow grinding and welding operations to be carried out in a centralized manner in the shed, facilitating centralized dust treatment. Each grinding station and welding station is respectively provided with a negative pressure dust collection device, which is connected to a temporary exhaust system to collect the dust generated by the station and discharge it to the outside. The negative pressure dust collection device can adopt a fixed exhaust fan or a dust collection device with a movable dust suction nozzle. One or more centralized grinding and welding work sheds can be arranged according to the specific area, floor, structure and on-site operation needs of the workshop.

[0035] In a further preferred embodiment, in a preferred embodiment, the work shed is configured as a negative pressure work shed to provide a negative pressure working environment, further reducing the risk of dust escape. In different embodiments, the work shed can be assembled on-site or assembled off-site and then transported to the work site. The work shed can be made of aluminum plates or steel plates welded together, or it can be built in the form of a frame pre-built with wood or steel pipes and then wrapped with iron sheets or aluminum sheets on the outside. In a preferred embodiment, the joint gaps in the work shed are filled with sealant to ensure the sealing of the work shed and reduce the escape of internal dust. The work shed is equipped with a ventilation fan, and is connected to a temporary exhaust system through the ventilation fan for exhaust and ventilation. In a preferred embodiment, the air volume of the ventilation fan should meet the ventilation volume in the work shed to reach at least 4 times / hour, so as to ensure that the smoke and dust generated during the grinding and welding operations can be discharged in time.

[0036] The decentralized fume purification system is set up at multiple workstations outside the centralized grinding and welding work shed, and can specifically include multiple self-priming grinding tools and / or welding fume exhaust devices, which are used to remove dust from grinding or welding workstations that cannot be concentrated in the work shed. Depending on the specific location and operation form of the decentralized fume purification system, some self-priming grinding tools and welding fume exhaust devices can be connected to a temporary exhaust system, which collects and discharges dust and smoke generated by construction work at the workstation. For those that are inconvenient to connect to a temporary exhaust system, dust can be collected and filtered by dust bags set on the self-priming grinding tools or welding fume exhaust devices. In a preferred embodiment, the self-priming grinding tools and welding fume exhaust devices are modular devices that can be deployed or relocated as a whole to facilitate adjustment of the construction work position at different stages of construction.

[0037] In a preferred embodiment, the temporary exhaust system's ducts are made of welded or riveted galvanized steel sheets to improve durability and reliability. For workstations that require frequent assembly and disassembly or movement, the temporary exhaust system can also use flexible ducts, such as plastic bellows, as exhaust ducts.

[0038] Step b): Next, categorize the construction work into essential on-site tasks and non-essential on-site tasks. Essential on-site tasks must be performed at a workstation in the on-site workshop, while non-essential on-site tasks can be performed off-site, with the equipment or workpiece subsequently transferred to the on-site workshop. Non-essential on-site tasks should be performed off-site, based on construction needs and on-site work capacity.

[0039] The necessary projects on site are further divided into on-site projects and non-on-site projects. On-site projects must be completed at a given workstation within the nuclear island building, such as welding of specific large structural parts or wall grinding. Non-on-site projects can be completed at non-given workstations. For example, welding of some flexible pipelines can be done by moving the joints to a convenient location for operation without having to be performed at a specific workstation. Non-on-site projects are centrally arranged for implementation in a centralized grinding and welding shed. A decentralized fume purification system is installed at the workstation of the on-site project, and at least part of the decentralized fume purification system is connected to a temporary exhaust system based on the specific location of the workstation where the on-site project is located, so as to collect the dust and smoke generated by grinding or welding and exhaust them outdoors. For operations where the amount of dust generated is small or the workstation is far away from the temporary exhaust system and the pipes and pipelines are difficult to lay, dust and smoke can be collected and filtered through dust bags.

[0040] Step c): After completing project division and dust removal system deployment, activate the dust removal system and implement each project. While implementing these projects, regular manual dust removal should be performed in the on-site workshops. This includes using vacuum cleaners or watering to reduce ground-based dust, further minimizing dust pollution. In a preferred embodiment, a dehumidifier should also be used to control humidity at the construction site, particularly in lower-level rooms or those with water pipes.

[0041] In a preferred embodiment, a dust removal method at a CAP1000 nuclear power plant construction site is implemented by the following steps:

[0042] Set up off-site workshops outside the nuclear power plant area, including pipeline workshops, main system workshops, electrical and instrumentation workshops, ventilation workshops and sandblasting and painting workshops. Set up on-site workshops inside the nuclear island building, and set up on the ground floor such as Figure 1 The centralized grinding and welding work shed shown in the figure adopts a negative pressure shed, which is 5 meters long, 3 meters wide and 2.5 meters high. It is constructed by splicing multiple aluminum plates 2. The joints 3 of the aluminum plates 2 are filled with sealant. A fan 1 is set on one side of the work shed. One end of the fan 1 is connected to the work shed, and the other end is connected to the temporary exhaust system. The exhaust volume of the fan 1 meets the requirements of completing 4 air changes per hour in the work shed (150m 3There are multiple welding and grinding stations in the work shed, each equipped with a negative pressure dust collector connected to a fan that extracts dust and sends it to a temporary exhaust system for discharge outdoors.

[0043] On-site construction projects are divided into construction projects that generate dust and smoke, such as grinding and welding, which can be completed outside the on-site workshop and are arranged to be carried out in off-site workshops; the work projects that must be carried out in the on-site workshop are further divided into non-situ projects that can be concentrated in the work shed and in-situ projects that need to be carried out at specific workstations in the nuclear island building. Non-situ projects include welding of some wiring harnesses or movable parts, and in-situ projects include grinding of walls, welding of fixed pipelines, etc.

[0044] A decentralized fume purification system is installed at the workstations of the in-situ project. Self-priming grinding tools are installed for grinding operations, and welding fume exhaust devices are installed for welding operations. Both the self-priming grinding tools and the welding fume exhaust devices are modular equipment that can be transported as a whole for easy placement at different workstations. Depending on the location of the workstation, the decentralized fume purification system near the temporary exhaust system pipeline can be connected to the temporary exhaust system pipeline, and the dust and smoke generated by grinding or welding can be directly discharged to the outside through the temporary exhaust system. For workstations that are far away or have limited space and are not convenient for laying temporary exhaust system pipelines, dust and smoke are collected and filtered through dust bags installed on the self-priming grinding tools and welding fume exhaust devices. The main pipeline of the temporary exhaust system is manufactured by welding galvanized steel plates, and the main pipeline is connected to the workstations of each in-situ project through plastic bellows.

[0045] An additional dehumidifier is installed in the room on the ground floor of the nuclear island building, which is connected to the water pipe, to control the air humidity at the work site.

[0046] At the start of construction work, the dust removal system is activated. A temporary exhaust system provides stable negative pressure dust collection, collecting dust and fumes from the centralized grinding and welding booth and the decentralized fume purification system connected to the temporary exhaust system, which is then discharged outdoors. For workstations not connected to the temporary exhaust system, dust and fumes are collected and filtered using dust bags, which are then manually cleaned regularly. The negative pressure environment of the booth further prevents the escape of dust generated by centralized work. Centralized operations simplify construction site management, reduce scattered dust sources, and facilitate on-site wiring and power supply. For work that must be conducted outside the booth, such as wall grinding, decentralized fume purification systems collect generated dust and fumes, effectively improving the construction environment. During operations, the site is cleaned regularly (e.g., daily or bi-weekly) through manual dust removal, such as vacuuming or watering the floor. This reduces dust deposited on the floor during construction and prevents secondary pollution caused by settled dust.

[0047] The nuclear power plant construction site dust removal system and dust removal method provided in the above embodiments can effectively improve the construction environment, reduce on-site dust, effectively improve the ergonomics of the work site, avoid damage to equipment caused by on-site dust, improve work efficiency, and improve construction economy.

[0048] The purpose of the above embodiments is to provide a further detailed description of the present invention in conjunction with the accompanying drawings so that those skilled in the art can understand the technical concept of the present invention. Within the scope of the present invention, optimization or equivalent replacement of the involved component structures or method steps, as well as combination of implementation methods in different embodiments without causing structural or principle conflicts, all fall within the scope of protection of the present invention.

Claims

1. A method for dust removal at a nuclear power plant construction site, characterized in that: The following steps are involved: Step a): Divide the construction site into off-site workshops and on-site workshops. The off-site workshop is located outside the nuclear island and includes one or more of a piping workshop, a main system workshop, an electrical and instrumentation workshop, a ventilation workshop, and a sandblasting and painting workshop; The on-site workshop is arranged in the nuclear island and is provided with a dust removal system, which includes one or more centralized grinding and welding work sheds, a decentralized fume purification system and a temporary exhaust system; Step b): Dividing the construction work items into necessary on-site items and non-necessary on-site items, wherein the necessary on-site items must be carried out at the workstations in the on-site workshop, and the non-necessary on-site items are not carried out at the workstations in the on-site workshop; Arrange the non-essential projects on site to be implemented in the off-site workshop; The necessary projects on the site are divided into on-site projects and non-on-site projects. The on-site projects must be completed on-site at a given workstation, and the non-on-site projects are completed at a non-given workstation. The non-on-site projects are arranged to be implemented in the centralized grinding and welding work shed. The decentralized fume purification system is installed at the workstation of the on-site project. The centralized grinding and welding work shed and at least part of the decentralized fume purification system are connected to the outdoors through the temporary exhaust system to discharge the fume generated by the operation to the outdoors. Step c): starting the dust removal system and executing the construction work project.

2. The method for dust removal at a nuclear power plant construction site according to claim 1, characterized in that: The centralized grinding and welding work shed is configured as a closed work shed, and a plurality of grinding stations and welding stations are arranged in the centralized grinding and welding work shed, each of which is provided with a negative pressure dust collection device, and the negative pressure dust collection device is connected to the temporary exhaust system to collect and discharge the dust generated by the grinding station and the welding station; The decentralized fume purification system is installed at multiple workstations outside the centralized grinding and welding work shed and includes multiple self-priming grinding tools and / or multiple welding fume exhaust devices. At least some of the self-priming grinding tools and / or the welding fume exhaust devices are connected to the temporary exhaust system to collect and discharge the generated dust. The self-priming grinding tool and the welding fume exhaust device that are not connected to the temporary exhaust system are equipped with dust collection bags for collecting dust.

3. The method for dust removal at a nuclear power plant construction site according to claim 1 or 2, characterized in that: The centralized grinding and welding work shed is configured as a negative pressure working environment.

4. The method for dust removal at a nuclear power plant construction site according to claim 1 or 2, characterized in that: The centralized grinding and welding work shed is equipped with a fan and is connected to the temporary exhaust system through the fan.

5. The method for dust removal at a nuclear power plant construction site according to claim 4, characterized in that: The air volume of the fan is such that the ventilation volume in the centralized grinding and welding work shed reaches at least 4 times per hour.

6. The method for dust removal at a nuclear power plant construction site according to claim 1 or 2, characterized in that: The centralized grinding and welding work shed is made of aluminum plates or steel plates, and sealant is provided at the joint gaps.

7. The method for dust removal at a nuclear power plant construction site according to claim 1 or 2, characterized in that: The pipes of the temporary exhaust system are made of galvanized steel plates or soft air ducts.

8. The method for dust removal at a nuclear power plant construction site according to claim 2, characterized in that: The self-priming grinding tool and the welding fume exhaust device are configured as a modular device.

9. The method for dust removal at a nuclear power plant construction site according to claim 1 or 2, characterized in that: The method also includes the step of controlling the humidity at the construction site using a dehumidifier.

10. The method for dust removal at a nuclear power plant construction site according to claim 1 or 2, characterized in that: The step c) further includes the step of performing thermal dust removal operations in the workshop at certain time intervals.

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