Sampling device for I-type iodine filter

Abstract

The invention provides a sampling device for an I-type iodine filter. The sampling device comprises a sampler body and a plurality of sampling cups, the sampler body and the I-type iodine filter are mounted in parallel or in series; the sampler body is provided with a windward side and a leeward side which are oppositely arranged; a plurality of guide grooves are formed in the sampler body and penetrate through the windward side and the leeward side; one sampling cup is correspondingly arranged in one guide groove, and activated carbon for sampling is arranged in the sampling cup. The sampling device is simple and compact in structure, and a bent frame of the nuclear air purification and treatment system and a wall body where the bent frame is located do not need to be modified; a redundant position of the I-type iodine filter on the framed bent can be used for parallel bypass sampling, and the framed bent can also be directly placed on a windward side of an air inlet of a room for series sampling; through flow debugging and setting of a plurality of sampling cups on the sampler body, representativeness of activated carbon in the sampling cups to activated carbon in the I-type iodine filter mounted on the framed bent is realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of nuclear air purification of nuclear power plants, and more particularly relates to a sampling device for an I-type iodine filter. BACKGROUND

[0002] During normal operation and accident conditions of a nuclear power plant, airborne radioactive gases are formed through various channels. Among them, gaseous radioactive iodine is very harmful to human health. In the nuclear air purification and treatment system of a nuclear power plant, an iodine filter is arranged to purify air and control the discharge amount of radioactive waste gas, so as to protect the staff of the power plant and the public from the harm of radioactive gas.

[0003] The iodine filter is an equipment for removing radioactive iodine from air flow by using impregnated activated carbon as adsorbent filter material. Currently, three types of iodine filters are mainly used in domestic nuclear power plants: I-type, II-type and III-type iodine filters. The above-mentioned iodine filters are all nuclear-grade spare parts, which need to meet the technical requirements of relevant nuclear-grade products.

[0004] The I-type iodine filter is a folded iodine filter, which mainly consists of a rectangular shell, an adsorption bed, a sealing gasket and fasteners, etc., and has a size of 610mmx610mmx292mm (widthxheightxdepth) and a rated air volume of 1200m 3 / h. This type of iodine filter is mainly applied to the second-generation nuclear power units of M310 / CRP1000 reactor type and is applied to various nuclear power plants.

[0005] According to the needs, the installation mode of the I-type iodine filter in the nuclear air purification and treatment system has two types. One is the shelf type installation: a plurality of iodine filters are installed in sequence on the shelf in the concrete purification chamber. The other is the box type installation: a plurality of iodine filters are installed on the installation bracket inside the metal box.

[0006] In the actual operation of a nuclear power plant, the performance and state of the I-type iodine filter need to be detected regularly to ensure that it can effectively remove airborne radioactive iodine. However, in the prior art, there is a lack of suitable sampling devices for the I-type iodine filter system installed in the shelf type. If a bypass sampling device is installed, there are problems such as damage to the wall or shelf, long construction period, etc.

[0007] Therefore, it is necessary to develop a sampling device specially applicable to the I-type iodine filter shelf type installation system to solve the above-mentioned problems. SUMMARY

[0008] The purpose of the present application is to provide a sampling device for an I-type iodine filter to solve the problem that in the prior art, there is a lack of suitable sampling devices for the I-type iodine filter system installed in the shelf type, and if a bypass sampling device is installed, there are problems such as damage to the wall or shelf, long construction period, etc.

[0009] In order to achieve the above object, the technical scheme adopted by the present application is: a sampling device for an I-type iodine filter is provided, comprising a sampler body and a plurality of sampling cups; the sampler body is installed in parallel or in series with the I-type iodine filter; the sampler body has a windward surface and a leeward surface arranged opposite to each other; a plurality of guide grooves are arranged on the sampler body, and the guide grooves penetrate through the windward surface and the leeward surface; one sampling cup is arranged in one guide groove, and activated carbon for sampling is arranged in the sampling cup.

[0010] Further, the sampling cup comprises an air inlet hood, a flow regulating cavity and a sampling tail pipe connected in sequence; the air inlet hood is used for air flow regulation; the flow regulating cavity is used for air inlet flow regulation; and the sampling tail pipe is used for placing activated carbon for sampling.

[0011] Further, the guide groove comprises a first groove body and a second groove body connected in sequence, the shape of the first groove body is matched with the shape of the flow regulating cavity, and the shape of the second groove body is matched with the shape of the sampling tail pipe.

[0012] Further, the first groove body is provided with a gasket near the second groove body.

[0013] Further, the second groove body is provided with an internal thread on the inner wall near the first groove body; the sampling tail pipe is provided with an external thread on the outer part near the flow regulating cavity, and the internal thread is connected with the external thread.

[0014] Further, the air inlet hood is in the shape of a horn.

[0015] Further, the flow regulating cavity is detachably connected with a windward panel, and the windward panel is used for regulating the air inlet flow.

[0016] Further, the windward panel is detachably connected with the flow regulating cavity, and a plurality of mesh holes are arranged on the windward panel.

[0017] As another optional scheme, the windward panel comprises a first laminated sheet and a second laminated sheet, the first laminated sheet and the second laminated sheet are arranged in a laminated manner and are rotationally connected; an air inlet is arranged on the first laminated sheet, and the size of the air inlet is adjusted by rotating the first laminated sheet or the second laminated sheet.

[0018] Further, the sampling tail pipe comprises a first tail pipe and a second tail pipe, a first end of the first tail pipe is connected with the flow regulating cavity, a second end of the first tail pipe is connected with the second tail pipe; a first perforated mesh plate is arranged between the first tail pipe and the second tail pipe, and a second perforated mesh plate is arranged in the second tail pipe; a carbon cavity is formed between the first perforated mesh plate and the second perforated mesh plate, and the carbon cavity is used for placing activated carbon for sampling.

[0019] Further, the first end of the first tail pipe is provided with a honeycomb mesh plate.

[0020] Further, the first end of the first tail pipe is provided with a gland, which is detachably connected with the first tail pipe, and the honeycomb mesh plate is installed on the gland.

[0021] Further, the gland is provided with an anemometer, which is used to measure the wind speed to adjust the air inlet of the flow adjusting cavity.

[0022] Further, the connection between the first perforated mesh plate and the first tail pipe or the second tail pipe is provided with a first sealing gasket, and the connection between the second perforated mesh plate and the second tail pipe is provided with a second sealing gasket.

[0023] Further, the first tail pipe and the second tail pipe are threadedly connected.

[0024] Further, the sampling device further comprises a sealing member, the I-shaped iodine filter is installed on a rack, the leeward surface of the sampler body is installed on the rack in parallel with the I-shaped iodine filter, and the sealing member is arranged between the leeward surface and the rack.

[0025] The sampling device for the I-shaped iodine filter provided in the application has the advantages that: compared with the prior art, the sampling device is simple and compact, and does not need to make any modification to the rack of the nuclear air purification and treatment system and the wall where the rack is located; the redundant position of the I-shaped iodine filter on the rack can be used for parallel bypass sampling, and the sampling device can also be directly placed at the windward position of the air inlet of a room for serial sampling; meanwhile, the sampling device can effectively meet the requirements of the sampling representativeness in the relevant standards. The cooperation of the plurality of sampling cups and the sampler body makes the sampling process more flexible and efficient, the flow of the plurality of sampling cups on the sampler body is adjusted and set, the representativeness of the activated carbon in the sampling cup to the activated carbon in the I-shaped iodine filter installed on the rack is realized, and thus the conversion of the radioactivity efficiency test method of the I-shaped iodine filter to the on-site leak detection test + carbon sample laboratory radioactivity efficiency test method is realized. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without any creative labor.

[0027] Figure 1 The three-dimensional structure schematic diagram of the sampling device for the I-shaped iodine filter provided in the embodiments of the application is shown in the drawings.

[0028] Figure 2 A cross-sectional exploded structure schematic diagram of a sampling device for a type I iodine filter provided by an embodiment of the present application;

[0029] Figure 3 A cross-sectional structure schematic diagram of a sampling cup in a sampling device for a type I iodine filter provided by an embodiment of the present application;

[0030] Figure 4 A structure schematic diagram of a windward panel in a sampling device for a type I iodine filter provided by an embodiment of the present application;

[0031] Figure 5 A structure schematic diagram of a first lamination in a sampling device for a type I iodine filter provided by an embodiment of the present application;

[0032] Figure 6 A structure schematic diagram of a honeycomb screen in a sampling device for a type I iodine filter provided by an embodiment of the present application.

[0033] In the drawings, various elements are labeled the same as follows:

[0034] 100 - a sampler body; 101 - a windward face; 102 - a leeward face; 103 - a guide groove; 131 - a first groove body; 132 - a second groove body; 104 - a gasket;

[0035] 200 - a sampling cup; 201 - an air inlet cover; 202 - a flow regulating cavity; 221 - a windward panel; 222 - a mesh hole; 223 - a first lamination; 224 - an air inlet; 203 - a sampling tail pipe; 231 - a first tail pipe; 232 - a second tail pipe; 204 - a first perforated screen; 205 - a second perforated screen; 206 - a carbon cavity; 207 - a honeycomb screen; 208 - a gland; 291 - a first sealing gasket; 292 - a second sealing gasket;

[0036] 300 - a sealing member. DETAILED DESCRIPTION

[0037] In order to make the technical problems, technical solutions and beneficial effects of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not intended to limit the present application.

[0038] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0039] It should be understood that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate directions or positions based on the directions or positions shown in the drawings, and are used only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0040] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise explicitly specified.

[0041] The iodine filter installed in the nuclear air purification and treatment system needs to be replaced and periodically tested for availability to ensure that the purification efficiency of the iodine filter is greater than the standard to meet the design requirements. There are two methods for availability test: one is direct verification method, and the other is indirect verification method. The direct verification method has a radioactivity efficiency test method, that is, a radioactive methyl iodine tracer is put on the upstream of the iodine filter in the field, and then sampling devices are used on the upstream and downstream of the iodine filter to sample the gas in the pipeline, the radioactivity of the sample is analyzed, and the purification efficiency of the iodine filter is obtained by using the volume activity ratio of the upstream and downstream, which is greater than the acceptance standard, to judge the availability of the iodine filter. The indirect verification method can use the field leak detection method, that is, "Freon", "cyclohexane" and other tracers are put on the upstream of the iodine filter in the field, and then sampling devices are used on the upstream and downstream of the iodine filter to sample the concentration of the gas in the pipeline, the concentration of the sample is analyzed, and the leakage rate of the iodine filter is obtained by using the concentration ratio of the upstream and downstream, which is greater than the leakage standard, and then the availability of the iodine filter is determined by combining the following methods:

[0042] (1) Method 1: According to the experience, it is considered that the filter material can maintain stable adsorption capacity within a certain time, so the periodic replacement strategy is adopted combined with the field leakage test of the iodine filter, the conservative equivalent evaluation conversion method of evaluating the efficiency by the leakage rate is adopted, and the availability of the iodine filter is evaluated. At present, the DVC iodine filter of the emergency ventilation system in the main control room of a certain nuclear power plant adopts the method of periodic replacement every year + "cyclohexane" field leakage test after replacement to conservatively confirm the availability.

[0043] (2) Practice 2: Nuclear air purification and treatment systems in nuclear power plants using Type II and Type III iodine filters are equipped with a bypass sampling cup device next to the iodine filter housing. The bypass sampling cup device is arranged in parallel with the iodine filter. There are usually 6 to 8 bypass sampling cups, and the sampling cups are loaded with a batch of nuclear-grade activated carbon from the iodine filter. Before the annual regular leak test, one bypass sampling cup is removed, and the carbon sample is sent to the thermal laboratory for radioactivity efficiency testing. If the on-site leak test and the nuclear-grade activated carbon efficiency test in the laboratory sampling cup are passed, the conclusion that the on-site iodine filter is usable is given.

[0044] Nuclear power plants using Type I iodine filters have also recently retrofitted their box-mounted iodine filter systems with bypass sampling cups. Six to eight sets of bypass sampling cups are installed in the bypass lines of the iodine filters. Before annual testing, one sampling cup is removed and the activated carbon sample in the cup undergoes an efficiency test in a radioactivity laboratory. Passing both the on-site leakage test and the laboratory sample efficiency test confirms the filter's usability.

[0045] However, there are currently no domestic designs or examples of using sampling cups for nuclear air purification and treatment systems using Type I iodine filter racks. This is because Type I iodine filter racks currently use direct verification methods such as radioactivity efficiency testing for serviceability verification, eliminating the need for bypass sampling cups. Furthermore, for existing Type I iodine filter racks, if bypass sampling cups are installed using the same methods as Type II and Type III box-type iodine filters, holes would need to be drilled or bored into the wall or rack housing the Type I iodine filter racks to install six to eight sets of sampling cups. This design would require structural and strength impact assessments of wall or rack damage, leading to long construction periods, high costs, and significant labor. For such systems, if the indirect verification approach of Method 2 is considered, innovative solutions to the bypass sampling issue are needed.

[0046] To ensure the representativeness of the sampling, according to the requirements of the Nuclear Air and Gas Handling Code (ASME / AG-1) standard, the nuclear-grade activated carbon in each sampling cup needs to be installed with activated carbon from the same batch and thickness as the iodine filter on the rack, and the airflow distribution of each sampling cup needs to meet the rated wind speed of the iodine filter carbon layer within ±10% of the rated wind speed, ensuring that the activated carbon in the sampling cup has the same airflow characteristics as the activated carbon in other iodine filters on the rack, so that the activated carbon in the sampling cup can represent the activated carbon in other iodine filters on the rack and be used to test the availability of this batch of activated carbon.

[0047] When a carbon sample with the same carbon layer thickness as other iodine filters is installed in a sampling cup of the same structure, in order to achieve the airflow distribution of the sampling cup meeting the requirements, each sampling cup needs to have the ability to adjust the flow rate, or be able to achieve uniform distribution of air volume between different sampling cups.

[0048] Through the air volume analysis, the installation quantity of part of nuclear air purification and treatment system, such as the rack type iodine filter of L8 / 9DVN001 / 002PI ventilation system, is redundant compared with the system air volume design, that is, the rated air volume of all installed iodine filters is greater than the rated air volume of the system, so the rack iodine filter can be reduced in quantity. Therefore, using the installation position of the redundant iodine filter of the rack, the sampling cup device is designed and installed, so that the simplest parallel bypass sampling cup device can be realized without changing any structure of the rack and the rack wall.

[0049] The relevant standards do not require that the sampling cup device must be arranged in parallel with the iodine filter, but require that the sampling cup device has representativeness and puts forward relevant technical requirements. Therefore, further, for the ventilation system without redundant installation position on the rack, such as the D9DVN001 / 002PI ventilation system, the device can also be used to install the device in the room of the rack, select the windward position near the air inlet of the front room of the rack, install the device, arrange the device in series with the rack iodine filter, and realize the representativeness of sampling through the structure and air volume adjustment of the sampling cup.

[0050] Based on this, the embodiment of the present application provides a sampling device for an I type iodine filter. Please refer to Figure 1 and Figure 2 The sampling device for the I type iodine filter comprises a sampler body 100 and a plurality of sampling cups 200; the sampler body 100 is installed in parallel or in series with the I type iodine filter; the sampler body 100 has an upwind face 101 and a leeward face 102 arranged oppositely; a plurality of guide grooves 103 are arranged on the sampler body 100, and the guide grooves 103 penetrate the upwind face 101 and the leeward face 102; one sampling cup 200 is arranged in one guide groove 103, and the sampling cup 200 is provided with activated carbon for sampling.

[0051] The sampling device for the type I iodine filter provided in the application has the advantages of simple and compact structure, and does not need to make any modification to the rack and the wall where the rack is located of the nuclear air purification and treatment system; the redundant position of the type I iodine filter on the rack can be used for parallel bypass sampling, and the sampling device can also be directly placed at the windward position of the air inlet of the room for series sampling; meanwhile, the sampling device can effectively meet the requirements of the sampling representativeness in the relevant standards. The cooperation of the plurality of sampling cups 200 and the sampler body 100 makes the sampling process more flexible and efficient, and the flow adjustment and setting of the plurality of sampling cups 200 on the sampler body 100 can realize the representativeness of the activated carbon in the sampling cup 200 to the activated carbon of the type I iodine filter installed on the rack, so as to realize the conversion of the radioactive efficiency test method of the type I iodine filter to the on-site leak detection test + carbon sample laboratory radioactive efficiency test method.

[0052] In the embodiment, the outer dimensions of the sampler body 100 can be consistent with the outer dimensions of the type I iodine filter, and the size of the sampler body 100 is 610mmx610mmx292mm (widthxheightxdepth). The sampler body 100 can be made of stainless steel to ensure its firmness, durability and good corrosion resistance.

[0053] As shown in Figure 1 The embodiment illustrates six sampling cups 200, and the number and distribution of the sampling cups 200 on the sampler body 100 can be adjusted and optimized according to the needs to meet different sampling requirements. For example, in some scenarios with high sampling frequency requirements, the number of sampling cups 200 can be appropriately increased to increase the sampling frequency as needed; and in the case of limited space, the number of sampling cups 200 can be reduced and the distribution can be optimized to ensure that the device can normally work in the limited space. At the same time, optimizing the distribution of the sampling cups 200 on the sampler body 100 can help to improve the uniformity and comprehensiveness of the sampling, and ensure that the sampled samples can more truly reflect the condition of the activated carbon in the type I iodine filter. By reasonably adjusting the number and distribution of the sampling cups 200, the working efficiency of the entire sampling device can be further improved, and the sampling cost can be reduced.

[0054] In the embodiment, the sampling cup 200 can be made of stainless steel, which has good corrosion resistance and can adapt to various chemical substances in the nuclear air environment, so as to ensure that the sampling cup 200 will not be corroded and damaged in the long-term use process, thereby ensuring the accuracy and stability of the sampling.

[0055] In one embodiment of the application, please refer to Figure 2 and Figure 3The sampling cup 200 comprises, in sequence, a wind guide cover 201, a flow regulating cavity 202, and a sampling tail pipe 203. The wind guide cover 201 is used for guiding the flow of gas. The flow regulating cavity 202 is used for regulating the flow of gas. The sampling tail pipe 203 is used for placing activated carbon for sampling.

[0056] In an embodiment of the present application, referring to Figure 2 The guide groove 103 comprises, in sequence, a first groove body 131 and a second groove body 132. The shape of the first groove body 131 matches the shape of the flow regulating cavity 202. The shape of the second groove body 132 matches the shape of the sampling tail pipe 203.

[0057] In this embodiment, the design of the guide groove 103 can better position and fix the sampling cup 200, so that the sampling cup 200 is more stable after installation, reducing the influence on the sampling result due to shaking or displacement during sampling. At the same time, the design matching the shapes of the flow regulating cavity 202 and the sampling tail pipe 203 is conducive to maintaining smoothness during the flow of gas, avoiding the situation of gas blockage or leakage, further ensuring the accuracy and reliability of sampling. Moreover, this structural design also facilitates the disassembly and replacement of the sampling cup 200. When the sampling cup 200 needs to be maintained or cleaned, it can be taken out from the guide groove 103 more conveniently, improving the convenience and efficiency of device maintenance.

[0058] In an embodiment of the present application, referring to Figure 2 The first groove body 131 is provided with a gasket 104 near the second groove body 132.

[0059] In this embodiment, by providing the gasket 104, the leakage of gas from the connection between the first groove body 131 and the second groove body 132 can be effectively prevented, ensuring the sealing performance of the entire sampling device, and further improving the precision of sampling. The gasket 104 is made of special radiation-resistant and high-temperature-resistant material. Under the complex working conditions of nuclear air environment, it can still maintain good elasticity and sealing performance. Even after long-term use, it will not age or deform due to radiation, high temperature, and other factors, ensuring the long-term stable operation of the sampling device, reducing frequent maintenance and replacement of parts due to sealing problems, and further reducing the use cost.

[0060] In an embodiment of the present application, the second groove body 132 is provided with an internal thread near the inner wall of the first groove body 131. The sampling tail pipe 203 is provided with an external thread near the outside of the flow regulating cavity 202. The internal thread is connected with the external thread.

[0061] When the sampling cup 200 is installed, after the sampling tail pipe 203 is inserted into the guide groove 103, the outer thread of the sampling tail pipe 203 and the inner thread in the guide groove 103 are engaged by rotating the sampling cup 200, so that the sampling cup 200 is installed on the sampler body 100, and the sealing between the sampling cup 200 and the guide groove 103 is realized through the gasket 104.

[0062] In this embodiment, the connection between the sampling tail pipe 203 and the second groove body 132 is more stable and reliable through the connection mode of the inner thread and the outer thread. This threaded connection structure is easy to install and disassemble. When the sampling device needs to be maintained, cleaned or replaced, the staff can conveniently separate or install the sampling tail pipe 203 from or on the second groove body 132, greatly improving the convenience of operation. At the same time, the tight fitting of the threaded connection further enhances the sealing of the entire sampling device, reduces the possibility of gas leakage due to loose connection, and further guarantees the accuracy of sampling, ensuring accurate sample acquisition under various complex working conditions.

[0063] In an embodiment of the present application, please refer to Figure 2 and Figure 3 , the air inlet hood 201 is trumpet-shaped.

[0064] In this embodiment, the air inlet hood 201 plays a role in guiding the flow. The trumpet-shaped air inlet hood 201 can effectively increase the air inlet area, so that more iodine-containing gas can smoothly enter the sampling device, thereby improving the sampling efficiency. The unique shape design can also guide and converge the airflow, making the gas flow more concentrated to the sampling area, ensuring the uniformity and representativeness of sampling. In addition, this shape helps to reduce the turbulence generated when the airflow enters the device, further improving the accuracy and reliability of sampling.

[0065] In an embodiment of the present application, please refer to Figure 3 and Figure 4 , the flow regulating cavity 202 is detachably connected with a windward panel 221, and the windward panel 221 is used to regulate the air inlet amount.

[0066] In this embodiment, the windward panel 221 is detachably connected with the flow regulating cavity 202, and by replacing windward panels 221 of different specifications, the size of the air inlet amount can be flexibly adjusted.

[0067] Specifically, the windward panel 221 can be fixed at the front end of the flow regulating cavity 202 in a screwing, threading or other manner, or can be fixed in a magnetic manner. The screwing or threading manner has the advantage of stable connection, and the operator can use common tools to install and disassemble, facilitating the replacement of different specifications of the windward panel 221. The magnetic fixing manner is more convenient, and the installation and removal of the windward panel 221 can be quickly completed without the aid of additional tools, greatly improving the efficiency of adjusting the air intake. The magnetic connection can also ensure better sealing between the windward panel 221 and the flow regulating cavity 202, avoiding gas leakage and affecting the accurate adjustment of the air intake.

[0068] In an embodiment of the present application, referring to Figure 4 , the windward panel 221 is detachably connected to the flow regulating cavity 202, and the windward panel 221 is provided with a plurality of mesh holes 222.

[0069] In this embodiment, the mesh holes 222 are circular in shape, and the diameters of the mesh holes 222 are carefully designed. The mesh holes 222 are uniformly distributed on the center of the windward panel 221, which can make the airflow entering the flow regulating cavity 202 more uniform and stable. The diameters of the mesh holes 222 of different specifications of the windward panel 221 are different. The windward panel 221 with larger diameter mesh holes 222 is suitable for situations requiring a large amount of air intake, such as when the air speed in the carbon cavity needs to be increased. The windward panel 221 with smaller diameter mesh holes 222 can effectively limit the air intake, and plays a key role when the air speed in the carbon cavity needs to be reduced. In addition, the shapes of the mesh holes 222 are not single, some can be circular and some can be annular. This diversified design further optimizes the air intake effect and helps to improve the adaptability of the sampling device to different working conditions.

[0070] In another embodiment of the present application, referring to Figure 5 , the windward panel 221 includes a first laminated sheet 223 and a second laminated sheet, the first laminated sheet 223 and the second laminated sheet are arranged in a laminated manner and are rotatably connected; the first laminated sheet 223 is provided with an air inlet 224, and the size of the air inlet 224 is adjusted by rotating the first laminated sheet 223 or the second laminated sheet.

[0071] In this embodiment, taking the first laminated sheet 223 as an example, the air inlet 224 on the first laminated sheet 223 can be gradually blocked by rotating the second laminated sheet, thereby achieving the purpose of adjusting the size of the air inlet 224. This adjustment method is simple and flexible, and the air intake can be adjusted in real time according to the actual sampling requirements.

[0072] To further realize the uniformity of the incoming air, the first lamination 223 and the second lamination have the same structure, the air inlet 224 is a ring-shaped groove, and a plurality of air inlets 224 are arranged along the circumferential direction of the first lamination 223. By adjusting the angle of the relative rotation of the first lamination 223 and the second lamination, the air volume is adjusted, and the uniformity of the incoming air is better.

[0073] In actual operation, the operator only needs to rotate the second lamination slightly, and can accurately adjust the uniformity of the incoming air according to the specific sampling requirements. This design not only ensures the stability of the incoming air, but also greatly improves the accuracy of sampling. Since the air inlets 224 are ring-shaped grooves and are uniformly distributed in the circumferential direction, the air can enter the sampling device in a relatively regular path, reducing the interference of airflow turbulence on the sampling results, and providing a stable and reliable sample basis for subsequent sample analysis.

[0074] In an embodiment of the present application, please refer to Figure 3 The sampling tail pipe 203 includes a first tail pipe 231 and a second tail pipe 232. The first end of the first tail pipe 231 is connected to the flow regulating cavity 202, and the second end of the first tail pipe 231 is connected to the second tail pipe 232. A first perforated screen 204 is arranged between the first tail pipe 231 and the second tail pipe 232, and a second perforated screen 205 is arranged in the second tail pipe 232. The first perforated screen 204 and the second perforated screen 205 form a carbon cavity 206 therebetween, and the carbon cavity 206 is used to place activated carbon for sampling.

[0075] In this embodiment, the size of the holes in the first perforated screen 204 and the second perforated screen 205 is smaller than the size of the activated carbon particles, which can effectively prevent the activated carbon particles from leaking out of the sampling tail pipe 203, and ensure that the activated carbon is stably placed in the carbon cavity 206 during the entire sampling process. At the same time, the design of the perforated screen can also ensure that the gas passes through smoothly and fully contacts with the activated carbon, so that the sampling is more representative. The thickness of the carbon cavity 206 is consistent with the thickness of the activated carbon in the carbon layer of the iodine filter, so as to ensure the representativeness of the activated carbon in the sample cup.

[0076] In an embodiment of the present application, please refer to Figure 3 and Figure 6 The first end of the first tail pipe 231 is provided with a honeycomb screen 207.

[0077] In this embodiment, the honeycomb net plate 207 is used to homogenize the flow field of the air in the sampling cup 200, so that the air flow can enter the subsequent pipeline more smoothly, reducing the influence on the representative of the carbon sample due to uneven air flow. After the treatment of the honeycomb net plate 207, the speed and direction of the air are more consistent, which is of great significance to improve the performance of the whole sampling device. At the same time, the material selection of the honeycomb net plate 207 is also carefully considered, and a corrosion-resistant and high-strength metal material is adopted to adapt to different working environments and ensure that it can still stably play its role in flow field homogenization during long-term use. This design not only optimizes the sampling process, but also further improves the reliability and accuracy of the sampling results, laying a solid foundation for the accurate evaluation of the performance of the iodine filter.

[0078] In an embodiment of the present application, please refer to Figure 3 The first end of the first tail pipe 231 is provided with a gland 208, which is detachably connected with the first tail pipe 231, and the honeycomb net plate 207 is installed on the gland 208.

[0079] In this embodiment, the installation and removal of the honeycomb net plate 207 are made more convenient by setting the gland 208. When the honeycomb net plate 207 needs to be cleaned or replaced, the operator only needs to easily detach the gland 208 to quickly take out the honeycomb net plate 207 for corresponding treatment. Moreover, the detachable connection ensures the stability of the connection between the gland 208 and the first tail pipe 231, and during the operation of the device, the gland 208 will not loosen due to vibration or air flow impact, thereby affecting the normal work of the honeycomb net plate 207. In addition, the material of the gland 208 is also compatible with the first tail pipe 231, which not only has good sealing performance to prevent air leakage from affecting the flow field homogenization effect, but also can resist the erosion of the external environment together with the first tail pipe 231, further prolonging the service life of the whole sampling device.

[0080] In an embodiment of the present application, a wind speed instrument is arranged in the gland 208, which is used to measure the wind speed to cooperate with the air intake adjustment of the flow adjusting cavity 202.

[0081] In this embodiment, the setting of the wind speed instrument can monitor the air flow speed in real time and provide accurate wind speed data for the flow adjusting cavity 202. The operator can more accurately control the air intake according to these data to ensure that the air flow entering the iodine filter meets the experimental requirements. By accurately grasping the wind speed, the air flow in different experimental scenarios can be effectively simulated, so that the performance of the iodine filter can be more comprehensively and accurately tested.

[0082] In an embodiment of the present application, please refer to Figure 3The first sealing gasket 291 is arranged at the joint between the first perforated screen 204 and the first tail pipe 231 or the second tail pipe 232, and the second sealing gasket 292 is arranged at the joint between the second perforated screen 205 and the second tail pipe 232.

[0083] In this embodiment, the first sealing gasket 291 and the second sealing gasket 292 are arranged to further enhance the sealing performance of the sampling tail pipe 203, so as to ensure that the activated carbon in the carbon cavity 206 can perform sampling work in a stable air flow environment. The first sealing gasket 291 and the second sealing gasket 292 are both made of rubber material, which has good aging resistance and chemical corrosion resistance. Even if they are placed in a nuclear air environment for a long time, they can still maintain good sealing effect. Such design not only ensures the accuracy of the sampling process, but also prolongs the service life of the sampling device and reduces the maintenance cost caused by sealing problems. In actual use, the staff can check the state of the sealing gasket regularly, and replace it in time if aging or damage is found, so as to ensure that the sampling device is always in the best working condition.

[0084] In an embodiment of the present application, the first tail pipe 231 and the second tail pipe 232 are threadedly connected.

[0085] In this embodiment, the threaded connection of the first tail pipe 231 and the second tail pipe 232 makes the installation and disassembly of the first tail pipe 231 and the second tail pipe 232 more convenient, which facilitates the operation during equipment maintenance, repair or component replacement. Moreover, the threaded connection can provide reliable sealing performance, reduce the possibility of gas leakage during sampling, ensure the stability of the sampling environment, and thus ensure the accuracy of the sampling data. In addition, the threaded connection has a simple structure, is easy to process and manufacture, reduces the production cost of the entire sampling device, and is also convenient for operators to master and grasp the connection and disassembly method, thereby improving work efficiency.

[0086] Specifically, the second end of the first tail pipe 231 is provided with external threads, and the upper end of the second tail pipe 232 is provided with internal threads. Through the cooperation of the external threads and the internal threads, the two can be tightly connected. During installation, only need to align the external threads of the first tail pipe 231 with the internal threads of the second tail pipe 232, and then rotate the first tail pipe 231 clockwise to complete the connection operation. During disassembly, the first tail pipe 231 can be easily separated from the second tail pipe 232 by rotating it counterclockwise.

[0087] In an embodiment of the present application, please refer to Figure 1 and Figure 2 The sampling device further comprises a sealing member 300, the Ι-shaped iodine filter is installed on the rack, and the leeward surface 102 of the sampler body 100 is installed on the rack in parallel with the Ι-shaped iodine filter; and the sealing member 300 is arranged between the leeward surface 102 and the rack.

[0088] In this embodiment, the seal 300 can adopt a whole sealing strip, the parameters of the sealing strip can be completely consistent with the I-type iodine filter sealing strip (outer side length 610mm*610mm, width 15mm, thickness 7.5-8mm), and need to have sufficient radiation resistance (maximum gamma radiation dose 10E6Gy), and the overall anti-seismic grade is 1F. In order to not affect the strength and rigidity of the installation rack, the mass of the whole sampling device cannot exceed 80KG.

[0089] The embodiment of the present application provides an assembly method of the sampling device for the I-type iodine filter.

[0090] When the I-type iodine filter on the rack is replaced, first, the assembly of each sampling cup 200 is carried out:

[0091] Each sampling cup 200 is disassembled, the second sealing gasket 292 is loaded in the second tail pipe 232, and then the second punched mesh plate 205 is loaded.

[0092] The nuclear-grade activated carbon of one batch of the I-type iodine filter on the field rack is loaded in the carbon cavity 206, the second tail pipe 232 is vibrated, the activated carbon is filled and compacted. The first punched mesh plate 204 is installed on the upper part of the carbon cavity 206, and then the first sealing gasket 291 is installed. The first tail pipe 231 is threadedly connected with the second tail pipe 232, and is screwed, so that the first sealing gasket 291 and the second sealing gasket 292 generate a pressing force, so as to ensure the integrity of the carbon cavity 206.

[0093] The assembled sampling cup 200 is inserted into the guide groove 103 of the sampler body 100 one by one, the sampling cup 200 is screwed, and the sampling cup 200 is fixed on the sampler body 100 through threads.

[0094] The embodiment of the present application provides an installation method of the sampling device for the I-type iodine filter.

[0095] The sampling device is installed relative to the rack-type installation iodine filter, and there are two installation methods: (1) parallel bypass type installation; (2) series type installation.

[0096] For the parallel bypass type installation method, the installed sampling device is arranged with the windward surface 102 facing the rack, the installation pressing plate on the rack is used, the sampling device and the remaining I-type iodine filter are installed on the rack.

[0097] For the series type installation method, only the sampling device needs to be installed on the fixing device of the I-type iodine filter, and the sealing strip on the windward surface 102 of the sampler body 100 does not need to be used, so that the device with the sealing strip used on the rack is directly used for the series type arrangement.

[0098] The debugging method of the sampling device for the type I iodine filter provided in the embodiment of the present application is as follows:

[0099] To achieve the effectiveness of sampling after installing the sampling device, the flow rate of each sampling cup 200 on the sampling device needs to be within the range of ±10% of the rated wind speed of the I-type iodine filter. Therefore, it is necessary to measure and adjust the wind speed of each sampling cup 200 of the sampling device. You can not install the windward panel 221 first, and install several temporary anemometers at the gland 208 of each sampling cup 200, at the front end of the honeycomb mesh plate 207. After the ventilation system equipped with the sampling device is started, obtain the anemometer readings at each sampling cup 200. Then, based on the debugging or laboratory flow comparison debugging experience, select the windward panel 221 with the appropriate flow rate or adjust the air volume device on the windward panel 221 before taking the anemometer reading. Through continuous adjustment, the wind speed of each sampling cup 200 is finally adjusted to within the range of ±10% of the rated wind speed, and then the anemometer is removed. It is necessary to record the flow setting method of the windward panel 221 of each position sampling cup 200.

[0100] The periodic sampling method of the sampling device for the type I iodine filter provided in the embodiment of the present application:

[0101] After the debugged sampling device is installed on-site, a replacement sampling cup 200 must be prepared before the annual leak rate test. The flow setting of the windward panel 221 of the replacement sampling cup 200 must be exactly the same as that of the sampling cup 200 to be replaced. The activated carbon loaded does not need to be the same batch of nuclear-grade activated carbon as the sampling cup 200 to be replaced, but must be properly filled with recently qualified nuclear-grade activated carbon.

[0102] After a sampling cup 200 is removed from the on-site sampling device, a replacement sampling cup 200 needs to be installed at that position to ensure that the flow conditions of each sampling cup 200 on the sampling device remain basically the same, so as to ensure the representativeness of the activated carbon in the remaining sampling cups 200.

[0103] If the Type I iodine filter on the rack fails the regular leak test, the laboratory efficiency of a certain sampling cup 200 fails, or all the initial sampling cups 200 have been used, it is necessary to replace the Type I iodine filter on the rack and replace the sampling device or all the sampling cups 200 thereon as a whole to ensure use in the next cycle.

[0104] The M310 / CPR1000 type nuclear power plant currently uses a radioactive efficiency test method to carry out the availability test of the I type iodine filter of the nuclear air purification and treatment system installed on the frame, and currently the non-radioactive test method is explored to replace the currently used radioactive efficiency test method, so as to reduce the risk of on-site radioactive operation and the related control cost of radioactive sources. Therefore, the sampling device of the present application can not modify the existing equipment components and walls on site, and can easily solve the problem of periodic sampling of on-site nuclear grade activated carbon after the test method is switched.

[0105] The sampling device of the present application can help the conversion of the on-site radioactive test method to the non-radioactive test method, which is beneficial to realize the on-site radiation safety, reduce the procurement, use and control cost of radioactive sources, and reduce the radioactive halogen emission to the environment.

[0106] The sampling device of the present application is one of the projects of the technical improvement research of the radioactive test method of the nuclear air purification and treatment system of a nuclear power plant. After successful implementation, it can be applied and popularized in related similar units.

[0107] The above only describes the preferred embodiments of the present application and does not limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A sampling device for a type I iodine filter, characterized in that, include: A sampler body, the sampler body and the type I iodine filter are installed in parallel or in series; the sampler body has a windward side and a leeward side that are arranged opposite to each other; the sampler body is provided with a plurality of guide grooves, the guide grooves passing through the windward side and the leeward side; A plurality of sampling cups are provided, one of the sampling cups is correspondingly arranged in one of the guide grooves, and activated carbon for sampling is provided in the sampling cups.

2. The sampling device for type I iodine filter as claimed in claim 1, wherein The sampling cup includes an air induced hood, a flow regulating chamber and a sampling tail pipe connected in sequence; the air induced hood is used for gas drainage; the flow regulating chamber is used for adjusting the air intake volume; and the sampling tail pipe is used for placing activated carbon for sampling.

3. The sampling device for type I iodine filter as claimed in claim 2, wherein The guide groove includes a first groove body and a second groove body that are connected in sequence. The shape of the first groove body matches the shape of the flow regulating cavity, and the shape of the second groove body matches the shape of the sampling tail pipe.

4. The sampling device for type I iodine filter as claimed in claim 3, wherein A gasket is provided on the first trough body near the second trough body.

5. The sampling device for type I iodine filter as claimed in claim 3, wherein The inner wall of the second trough body close to the first trough body is provided with an internal thread; the outer side of the sampling tail pipe close to the flow regulating cavity is provided with an external thread, and the internal thread is connected to the external thread.

6. The sampling device for type I iodine filter as claimed in claim 2, wherein The air induced hood is in a trumpet shape.

7. The sampling device for type I iodine filter as claimed in claim 2, wherein A windward panel is detachably connected to the flow regulating cavity, and the windward panel is used to adjust the air intake volume.

8. The sampling device for type I iodine filter as claimed in claim 7, wherein The windward panel is detachably connected to the flow regulating chamber, and a plurality of mesh holes are provided on the windward panel.

9. The sampling device for type I iodine filter as claimed in claim 7, wherein The windward panel includes a first laminate and a second laminate, which are stacked and rotatably connected. The first laminate is provided with an air inlet, and the size of the air inlet is adjusted by rotating the first laminate or the second laminate.

10. The sampling device for type I iodine filter according to claim 2, wherein The sampling tail pipe includes a first tail pipe and a second tail pipe, the first end of the first tail pipe is connected to the flow regulating chamber, and the second end of the first tail pipe is connected to the second tail pipe; a first perforated mesh plate is provided between the first tail pipe and the second tail pipe, and a second perforated mesh plate is provided in the second tail pipe; a carbon cavity is formed between the first perforated mesh plate and the second perforated mesh plate, and the carbon cavity is used to place activated carbon for sampling.

11. The sampling device for type I iodine filter according to claim 10, wherein A honeycomb mesh plate is provided at the first end of the first tail pipe.

12. The sampling device for type I iodine filter according to claim 11, wherein A gland is provided at the first end of the first tail pipe. The gland is detachably connected to the first tail pipe, and the honeycomb mesh panel is mounted on the gland.

13. The sampling device for type I iodine filter according to claim 12, wherein An anemometer is provided in the gland, and the anemometer is used to measure wind speed to coordinate with the air inlet adjustment of the flow regulating chamber.

14. The sampling device for type I iodine filter according to claim 10, wherein A first sealing gasket is provided at the connection between the first perforated mesh plate and the first tail pipe or the second tail pipe; a second sealing gasket is provided at the connection between the second perforated mesh plate and the second tail pipe.

15. The sampling device for type I iodine filter according to claim 10, wherein The first tail pipe and the second tail pipe are threadedly connected.

16. The sampling device for type I iodine filter according to any one of claims 1 to 15, characterized in that: The sampling device further includes a seal, the type I iodine filter is mounted on a rack, the leeward side of the sampler body and the type I iodine filter are mounted in parallel on the rack; the seal is arranged between the leeward side and the rack.

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