Air filtering device

Abstract

The utility model belongs to the technical field of gas treatment of nuclear power plants, and discloses a gas filtering device, which is used for filtering gas generated by nuclear wastes and comprises a cover cap, a pipeline, a filtering mechanism, a fan and a sealing element, the cover cap is used for sealing and covering a container for containing nuclear waste, the sealing piece is arranged on the peripheral edge of the cover cap, and a connector is formed in the cover cap; the pipeline comprises a first pipeline, one end of the first pipeline is connected with the connector, the other end of the first pipeline is connected with an inlet of the filtering mechanism, and the fan is used for providing power for enabling gas generated by the nuclear waste to flow towards the first pipeline and the filtering mechanism. According to the utility model, the problem that the treatment of carbon 14 in a ventilation system in a nuclear power plant is uneconomical and unrealistic is solved, the scheme can realize quick assembly and disassembly, and the radiation influence of the nuclear power plant on the surrounding public and environment is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of gas treatment in nuclear power plants, and particularly relates to a gas filtering device. Background Technique

[0002] With the development of nuclear power plants, the emission control of radioactive substances has become an important issue. During the operation of nuclear power plants, carbon-14 is generated. It initially exists in the reactor coolant and is mainly released in gaseous form during the processes of coolant letdown degassing and pressurizer venting, with some remaining in solid or liquid waste. Since the coolant in the primary loop directly contacts the reactor core, the coolant becomes radioactive, and the primary loop coolant is basically emptied in each fuel cycle. Therefore, all the carbon-14 generated in the primary loop is released into the environment. Although the generation amount of carbon-14 in pressurized water reactor nuclear power plants is relatively low, its half-life is as long as 5730 years, and it is easy to enter the human body and remain through the food chain. It has become the nuclide that contributes the most to the effective dose of the surrounding public during the normal operation of nuclear power plants, with a dose contribution exceeding 50%. By reducing the emission amount of carbon-14, the radiation impact on the environment can be effectively reduced.

[0003] Currently, there is no effective treatment method for gaseous carbon-14 in nuclear power plants. This is because carbon-14 is mainly released in gaseous form through the power plant chimney, and the chimney ventilation volume is large. It is neither economical nor feasible to treat carbon-14 in the ventilation system.

[0004] To solve the above problems, through research, it is found that during the actual operation of nuclear power plants, the contribution of gaseous carbon-14 in the spent fuel building area is relatively high, accounting for about 30% of the gaseous carbon-14 emissions from the chimney. Moreover, about 90% of the gaseous carbon-14 released in this area is inorganic carbon ( 14 CO2), which is convenient for adsorption and solidification. Since the gaseous carbon-14 in the spent fuel building mainly comes from the coolant in the spent fuel pool and its surrounding areas, if the gaseous carbon-14 in this area can be centrally collected and absorbed, the volume of the treated air will be effectively reduced, and the generation amount of solid waste will be greatly reduced. Content of the Utility Model

[0005] The purpose of the utility model is to provide a gas filtering device, aiming to solve the problems that it is neither economical nor practical to treat carbon-14 in the ventilation system of nuclear power plants.

[0006] To achieve this purpose, the utility model adopts the following technical solutions:

[0007] A gas filtering device is used to filter the gas generated by nuclear waste in a nuclear power plant. The gas filtering device includes a cover, a pipeline, a filtering mechanism, a fan, and a seal; the cover is used to cover the container for holding nuclear waste, the seal is arranged on the peripheral edge of the cover, and an interface is opened on the cover; the pipeline includes a first pipeline, one end of the first pipeline is connected to the interface, the other end of the first pipeline is connected to the inlet of the filtering mechanism, and the fan is used to provide the power for the gas generated by nuclear waste to flow to the first pipeline and the filtering mechanism.

[0008] Preferably, the cover includes a support member and an outer covering layer. The outer covering layer covers the upper end of the support member. The seal is arranged on the peripheral edge of the outer covering layer, and the interface is opened on the outer covering layer.

[0009] Preferably, the support member is a mesh structure.

[0010] Preferably, the gas filtering device further includes a micro - pressure gauge. The micro - pressure gauge is arranged inside the cover. An observation port is opened on the outer covering layer. The observation port is an openable and closable opening, and the micro - pressure gauge is facing the observation port.

[0011] Preferably, at least one opening is opened on the outer covering layer, and the opening is an openable and closable opening.

[0012] Preferably, the filtering mechanism includes a housing, a partition plate, and an adsorption material. The partition plate is arranged inside the housing. A plurality of holes are opened on the partition plate, and the adsorption material is arranged in the holes. The pipeline further includes a second pipeline, and the outlet of the filtering mechanism is connected to the second pipeline.

[0013] Preferably, the fan is arranged in the second pipeline.

[0014] Preferably, the fan is arranged inside the housing and is located downstream of the partition plate.

[0015] Preferably, the adsorption material is lithium hydroxide, soda lime, or potassium superoxide.

[0016] Preferably, it further includes a carbon dioxide concentration meter, and the carbon dioxide concentration meter is arranged on the first pipeline and / or the second pipeline.

[0017] Beneficial effects:

[0018] The utility model provides a gas filtering device. By installing a cover on the container for holding nuclear waste in a nuclear power plant, connecting the cover and the filtering mechanism through a pipeline, using a seal to seal the peripheral edge of the cover, and using a fan for exhaust, the harmful gas generated by nuclear waste can be collected and adsorbed and solidified; the scheme of the utility model has a simple structure, convenient device operation and implementation, can be quickly installed and disassembled, can effectively adsorb and filter the harmful gas generated by nuclear waste without affecting the safe operation of nuclear power, further reduces the volume of air to be treated for removing harmful gas, and thus reduces the radiation impact of the nuclear power plant on the surrounding public and environment. Brief Description of the Drawings

[0019] Figure 1 is a top view of the air filtering device provided in this embodiment;

[0020] Figure 2 is a schematic diagram of the decarbonization device in the air filtering device provided in this embodiment;

[0021] Figure 3 is a schematic diagram of the principle of the decarbonization device in the air filtering device provided in this embodiment;

[0022] Figure 4 is a cross-sectional view of the track and the rail gripper of the air filtering device provided in this embodiment.

[0023] In the figure:

[0024] 1. Cover; 11. Support member; 12. Outer covering; 121. Observation port; 122. First opening; 123. Second opening;

[0025] 2. Pipe; 21. First pipe; 22. Second pipe;

[0026] 3. Filter mechanism; 31. Outer shell; 32. Partition board; 33. Hole;

[0027] 4. Fan; 5. Sealing member; 6. Interface; 7. Track;

[0028] 8. Rail gripper; 81. Eyelet; 82. Rail gripper installation position. Detailed Description of the Embodiment

[0029] The following further elaborates on the present utility model in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are merely for explaining the present utility model and not for limiting it. Additionally, it should be noted that for the sake of description, only the parts related to the present utility model rather than all the structures are shown in the drawings.

[0030] In the description of the present utility model, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0031] In the present utility model, unless otherwise clearly specified and defined, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may also include the situation where the first and second features are not in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "under" and "beneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0032] In the description of this embodiment, the orientation or positional relationships such as "above", "below", "right", etc. are based on the orientation or positional relationships shown in the drawings. They are only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0033] As Figures 1 - 3 shown, this embodiment provides a gas filtering device for filtering the gas generated by nuclear waste in a nuclear power plant. The gas filtering device includes a cover 1, a pipeline 2, a filtering mechanism 3, a fan 4 and a seal 5; the cover 1 is used to cover the container for holding nuclear waste (the container for holding nuclear waste includes the spent fuel pool, the water gate and the fuel transportation channel in the fuel building of the nuclear power plant), the seal 5 is arranged on the peripheral edge of the cover 1 to ensure the sealing between the inside of the cover 1 and the outside. An interface 6 is opened on the cover 1. The pipeline 2 includes a first pipeline 21 and a second pipeline 22. One end of the first pipeline 21 is connected to the interface 6, and the other end is connected to the inlet of the filtering mechanism 3. The outlet of the filtering mechanism 3 is connected to the second pipeline 22. The fan 4 is used to provide the power for the gas generated by the nuclear waste to flow through the first pipeline 21, the filtering mechanism 3 and the second pipeline 22; the filtering mechanism 3 captures and solidifies gaseous carbon-14 in the gas.

[0034] As Figure 1As shown, the cover 1 includes a support member 11 and an outer covering layer 12. The support member 11 serves as the main supporting structure of the cover 1. In this embodiment, a mesh structure is adopted, and a high-strength, low-density sling net is selected, so that the support member 11 has the characteristics of high strength and light weight. In addition, in the case where there are other equipment or devices on the spent pool, the support member 11 with a mesh structure can easily cross these obstacles to ensure that the installation of the cover 1 is not affected. Optionally, the material of the support member 11 can be selected from polyester, nylon, Dyneema, etc. The anchor point of the net can be set on the ground track 7 of the fuel grabber, and the track 7 is fixed by a track clamp 8. The track clamp 8 is set on the track clamp installation position 82 on the track 7. The anchor points of the net are penetrated through the eyelets 81 on the track clamp 8. This installation method is stable and reliable, and is easy to disassemble and adjust when needed. There is no need to punch holes on site, which is convenient to implement and has a short construction period. It is easy to disassemble and install before and after the loading and replacement of the spent pool. It should be noted that the fuel grabber is a special device used to operate and transport nuclear fuel assemblies in nuclear facilities such as nuclear power plants. It is a prior art and will not be described in detail here. In addition, the cover 1 can also adopt a push-pull awning type or an electric soft film cover type. According to different needs and conditions, a suitable cover form can be selected to achieve the best sealing effect.

[0035] The outer covering layer 12 covers the upper end of the support member 11 , and the outer covering layer 12 is made of a waterproof, windproof, high-strength and heat-resistant cover cloth material, and can be a three-proof cloth or a silicone cloth. The outer covering layer 12 is provided with an interface 6 for connecting the first pipe 21 .

[0036] Optionally, an observation port 121 is provided on the outer covering layer 12, and the observation port 121 is designed to be openable and closable. A micromanometer is provided inside the cover 1, and the micromanometer is directly opposite to the observation port 121, so that the staff can understand the exhaust data conveniently. At the same time, it is ensured that the cover 1 is in a slightly negative pressure state relative to the external environment when the fan 4 is running. In this embodiment, the micromanometer can be an inclined U-tube liquid level differential micromanometer. After the exhaust system runs stably, the inspection personnel can directly read and record the negative pressure inside the cover 1 through the micromanometer.

[0037] Optionally, at least one opening is further provided on the outer cover 12. In this embodiment, two openings are provided, namely a first opening 122 and a second opening 123. Each opening is provided with a component capable of opening and closing the opening, and the opening can be opened and closed by a zipper and / or a Velcro. The first opening 122 and the second opening 123 are used for boron concentration monitoring and liquid level observation, and can also be temporarily opened in an emergency to release internal gas. The number of openings is not limited to this embodiment, and can also be one, or more than two.

[0038] The seal 5 plays a crucial role in ensuring the effectiveness of the air filtration device. In this utility model, a magnetic attraction device or an elastic rubber pad is used in combination with a pressure strip to firmly attach the outer covering layer 12 to the bottom surface of the operation platform in the fuel building, preventing air leakage through the gaps. This sealing method not only has a good sealing effect, but more importantly, it is convenient for installation and disassembly, without complex operations such as on-site drilling. In this embodiment, a magnetic attraction device is used for sealing. Magnetic attractions are provided at the contact parts such as the ground in the fuel building and / or the track 8 and / or the railing rooting points for fixing the outer covering layer 12. At the same time, steel wires are used to connect the magnetic attractions to the rail gripper 8 to prevent them from falling into the spent fuel pool, further improving the safety of the device.

[0039] The filtering mechanism 3 includes a housing 31, a partition plate 32, and an adsorption material. The partition plate 32 is arranged inside the housing 31. A plurality of holes 33 are formed in the partition plate 32, and the adsorption material is arranged in the holes 33. In this embodiment, honeycomb-shaped holes are formed in the partition plate 32. This design of the honeycomb-shaped partition plate can increase the contact area between the adsorption material and air, improving the absorption efficiency. In other embodiments, the number of partition plates 32 can be multiple, and adsorption materials are arranged in the holes 33 formed in each partition plate 32. The multiple partition plates 32 are arranged at intervals along the exhaust direction inside the housing 31 of the filtering mechanism 3, thereby enhancing the adsorption amount and adsorption effect of the filtering mechanism 3 on gaseous carbon-14. The adsorption material can adopt lithium hydroxide, soda lime, or other renewable or non-renewable capture technologies, such as alcohol ammonia method, pressure swing / temperature swing adsorption, potassium superoxide and other adsorption schemes. After adsorption, the partition plate 32 and the adsorption material are disposed of together as waste. The spent adsorption material is a non-flowing, chemically stable and radiation-stable waste, without flammable, explosive substances or substances that react with the surrounding medium, generate gas, undergo biodegradation or radiation decomposition. Before removing the adsorption material, it should be dehydrated, and after removal, it should be compressed and filled into the existing waste steel barrels in the power plant for grouting and fixing treatment.

[0040] The fan 4 can be arranged on the second pipeline 22. In addition, the fan 4 can also be arranged inside the housing 31 and downstream of the partition plate 32.

[0041] The fan 4 is used to extract the air inside the cover 1, making it pass through the filtering mechanism 3 to adsorb and solidify the gaseous carbon-14 therein. During the exhaust process of the fan 4, the cover 1 can also be supplemented with air through the first opening 122 and / or the second opening 123.

[0042] Optionally, the fan 4 adopts a variable-frequency motor to adjust the exhaust air volume, so as to control the reaction time between the discharged gas and the filtering mechanism 3, achieving a better adsorption effect.

[0043] Optionally, a carbon dioxide concentration meter is provided on the first pipeline 21 and / or the second pipeline 22 to detect the change in the carbon dioxide concentration in the gas, so as to confirm whether the adsorption material has completed the adsorption of gaseous carbon-14.

[0044] Optionally, carbon dioxide concentration meters are provided on both the first pipeline 21 and the second pipeline 22, that is, the carbon dioxide concentration meters are arranged upstream and downstream of the filtering mechanism 3. By comparing the carbon dioxide concentrations upstream and downstream, the adsorption effect of the filtering mechanism can be judged. And when the carbon dioxide concentration meter on the second pipeline 22 shows an increase in the carbon dioxide concentration, the exhaust air volume of the fan 4 can be adjusted in time and the adsorption material in the filtering mechanism 3 can be replaced.

[0045] Specific implementation steps:

[0046] First, according to the size and shape of the spent fuel pool, select the appropriate form and size of the cover 1. Prepare the required components such as pipelines 2, filtering mechanism 3, fan 4, seal 5, support 11, outer covering 12, etc. At the same time, check the quality and integrity of each component to ensure that it meets the design requirements.

[0047] For the support 11 with a mesh structure, install it above the container for storing nuclear waste according to the design requirements, and fix it on the ground track 7 through anchor points to ensure that the installation of the support 11 is firm and reliable and can bear the weight of the outer covering 12 and external pressure. Then, cover the outer covering 12 on the support 11, adjust the position so that it completely covers the spent fuel pool and its surrounding area, and use the seal 5 to press the outer covering 12 tightly against the floor of the fuel building operation platform to ensure the sealing performance.

[0048] Connect one end of the first pipeline 21 to the interface 6 on the cover 1, and the other end to the inlet of the filtering mechanism 3. Connect one end of the second pipeline 22 to the outlet of the filtering mechanism 3, and the other end to the fan 4. Ensure that the connections of the first pipeline 21 and the second pipeline 22 are firm and reliable without leakage. Install carbon dioxide concentration meters on the first pipeline 21 and the second pipeline 22 respectively to monitor the change in the carbon dioxide concentration in the gas.

[0049] Connect the power supply of the fan 4 and debug the exhaust air volume of the fan 4 to make it meet the design requirements.

[0050] Install a micro - pressure gauge inside the cover 1 so that it faces the observation port 121 directly, ensuring that the installation of the micro - pressure gauge is firm and reliable and can accurately measure the pressure change inside the cover.

[0051] After the installation is completed, debug the air filtration device. Check the working status of each component to ensure its normal operation. Start the fan 4 and observe the pressure change and gas flow in the cover 1. During operation, regularly monitor the readings of the carbon dioxide concentration meter to timely understand the working status of the filtration mechanism 3 and ensure that it can effectively capture and solidify gaseous carbon dioxide.

[0052] The air filtration device provided by the present utility model filters the gas generated by nuclear waste by installing a special cover 1 on the container for storing nuclear waste and connecting the filtration mechanism 3 and the fan 4, effectively reducing the emission of gaseous carbon-14 in nuclear power plants and reducing the radiation impact on the surrounding public. This device has the advantages of small waste volume, convenient operation and implementation, high safety and reliability, etc., providing strong support for the environmental protection and sustainable development of nuclear power plants. In practical applications, appropriate cover forms and adsorption materials can be selected according to different requirements and conditions to achieve the best filtration effect. At the same time, it is necessary to strengthen the maintenance and management of the device, regularly check and replace the adsorption materials to ensure the long-term stable operation of the device.

[0053] Obviously, the above-mentioned embodiments of the present utility model are merely examples for clearly illustrating the present utility model and are not limitations on the implementation manners of the present utility model. For those of ordinary skill in the art, various obvious changes, re-adjustments and substitutions can be made without departing from the protection scope of the present utility model. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present utility model shall be included in the protection scope of the claims of the present utility model.

Claims

1. A gas filtering device, characterized in that, For filtering the gas generated by nuclear waste in a nuclear power plant, the gas filtering device includes a cover (1), a pipeline (2), a filtering mechanism (3), a fan (4) and a seal (5); the cover (1) is used to cover the container for storing nuclear waste, the seal (5) is arranged on the peripheral edge of the cover (1), and an interface (6) is opened on the cover (1); the pipeline (2) includes a first pipeline (21), one end of the first pipeline (21) is connected to the interface (6), the other end of the first pipeline (21) is connected to the inlet of the filtering mechanism (3), and the fan (4) is used to provide the power for the gas generated by the nuclear waste to flow to the first pipeline (21) and the filtering mechanism (3).

2. The air filtration device according to claim 1, characterized in that, The cover (1) includes a support member (11) and an outer covering layer (12), the outer covering layer (12) covers the upper end of the support member (11), the seal (5) is arranged on the peripheral edge of the outer covering layer (12), and the interface (6) is opened on the outer covering layer (12).

3. The air filtering device according to claim 2, wherein The support member (11) is a mesh structure.

4. The air filter device according to claim 2, wherein, The gas filtering device further includes a micro - pressure gauge, the micro - pressure gauge is arranged inside the cover (1), an observation port (121) is opened on the outer covering layer (12), the observation port (121) is an openable and closable opening, and the micro - pressure gauge faces the observation port (121).

5. The air filter device according to claim 2, characterized in that, At least one opening is opened on the outer covering layer (12), and the opening is an openable and closable opening.

6. The air filtering device according to claim 1, wherein The filtering mechanism (3) includes a housing (31), a partition plate (32) and an adsorption material, the partition plate (32) is arranged inside the housing (31), a plurality of holes (33) are opened on the partition plate (32), the adsorption material is arranged in the holes (33), the pipeline (2) further includes a second pipeline (22), and the outlet of the filtering mechanism (3) is connected to the second pipeline (22).

7. The air filter device according to claim 6, characterized in that The fan (4) is arranged inside the housing (31) and is located downstream of the partition plate (32).

8. The air filter device according to claim 6, wherein The fan (4) is arranged in the second pipeline (22).

9. The air filter device according to claim 6, wherein The adsorption material is lithium hydroxide, soda lime or potassium superoxide.

10. The air filtration device according to any one of claims 6-9, characterized in that, It further includes a carbon dioxide concentration meter, and the carbon dioxide concentration meter is arranged on the first pipeline (21) and / or the second pipeline (22).

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