Containment atmosphere monitoring system and containment pressure relief filtering device

Abstract

The utility model relates to the technical field of nuclear island ventilation and air conditioning systems, and discloses a containment atmosphere monitoring system and a containment pressure relief filtering device.The containment pressure relief filtering device comprises a pressure relief pipeline and a pre-filtering bypass, and the pressure relief pipeline is communicated with the outlet end of the pre-filtering bypass; a first filter and a check valve are arranged on the pressure relief pipeline, and a second filter is arranged on the pre-filtering bypass. According to the utility model, the pre-filtering bypass connected in parallel with the pressure relief pipeline is constructed on the containment pressure relief filtering device, so that the pre-filtering bypass can share the filtering pressure when the radioactive gas is subjected to pressure relief, and the possibility of leakage of the radioactive gas is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of nuclear island ventilation and air conditioning systems, in particular to a containment atmosphere monitoring system and a containment pressure relief filtering device. Background Art

[0002] The containment vessel is the "third barrier" to protect nuclear power plants. Protecting its integrity after an accident is an issue that must always be considered during the design and operation of nuclear power plants. After an accident, not only must the pressure relief of the containment vessel be guaranteed, but the safety of gas release during the pressure relief process must also be guaranteed.

[0003] Radioactive contamination refers to the accumulation or presence of radioactive materials inside or on the surface of solids, liquids, or gases. Such radioactive contamination is dangerous due to the radioactive decay of contaminants, because when contaminants collapse, harmful ionizing radiation such as alpha (α) particles, beta (β) particles or gamma (γ) rays or neutrons is released. With the explosion of atomic bombs in the atmosphere or the destruction of nuclear containment buildings, air, soil, humans, plants and animals are contaminated by nuclear fuel and nuclear fission products. Such examples include Bikini Atoll, Rocky Flats Plant in Colorado, USA, Fukushima Daiichi Nuclear Power Plant Accident and Chernobyl Nuclear Power Plant Accident. Therefore, when an accident caused by nuclear power generation occurs, there is an urgent need for early response to radioactive materials, so filtering devices are indispensable. Most of the radioactive gas effluents from nuclear power plants are treated before being discharged into the atmosphere. The current common method is to extract radioactive particles from the effluent before discharging the radioactive gas effluent into the atmosphere.

[0004] The existing containment pressure relief filtering device chooses to directly set a filter on the pressure relief pipeline, and uses the filter to filter the radioactive gas that needs to be released in the containment after the loss of coolant accident (LOCA). Therefore, when the containment is depressurized and exhausted after the loss of coolant accident (LOCA), a large amount of radioactive gas needs to be processed by the filter. However, due to the limited filtering capacity of the filter, it will eventually cause excessive energy to accumulate in the filter, thereby causing the filtering effect to deteriorate and the radioactive gas to be discharged into the environment. Utility Model Content

[0005] The purpose of the present application is to provide an improved containment atmosphere monitoring system and a containment pressure relief filter device, aiming to solve the problem of poor radioactive gas filtering effect in the existing containment pressure relief filter device.

[0006] The utility model adopts the following technical solutions:

[0007] A containment pressure relief filtering device is constructed, comprising a pressure relief pipeline and a pre-filter bypass, wherein the pressure relief pipeline is connected to the outlet end of the pre-filter bypass; a first filter and a check valve are arranged on the pressure relief pipeline, and a second filter is arranged on the pre-filter bypass.

[0008] In some embodiments, the check valve comprises a swing check valve.

[0009] In some embodiments, the action setting value of the check valve is 1.0 bar gauge pressure.

[0010] In some embodiments, the filtration pressure difference of the first filter is smaller than that of the second filter.

[0011] In some embodiments, the check valve is disposed at an outlet end of the first filter.

[0012] In some embodiments, the containment pressure relief filtering device further includes an output pipeline, the outlet end of the pressure relief pipeline and the outlet end of the pre-filtration bypass are both connected to the inlet end of the output pipeline, and the outlet end of the output pipeline is arranged outside the containment; a third filter is arranged at the outlet end of the output pipeline.

[0013] In some embodiments, the third filter comprises a sand filter.

[0014] In some embodiments, a valve is provided on the output pipeline, and the valve is provided outside the containment vessel.

[0015] In some embodiments, the output pipeline further includes a penetration piece, and the penetration piece is disposed on the containment shell.

[0016] A containment atmosphere monitoring system is constructed, comprising any one of the containment pressure relief filtering devices described above.

[0017] The utility model has the following advantages:

[0018] The utility model constructs a pre-filter bypass in parallel with the pressure relief pipeline on the containment pressure relief filter device, so that when the radioactive gas is depressurized, the pre-filter bypass can share the filtering pressure, thereby reducing the possibility of radioactive gas leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solution of the utility model, the utility model will be further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the following drawings only show certain embodiments of the utility model, and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work. In the drawings:

[0020] Figure 1 It is a structural schematic diagram of a containment pressure relief filter device in one embodiment of the utility model;

[0021] Figure 2 It is a structural schematic diagram of the containment atmosphere monitoring system in the second embodiment of the utility model. DETAILED DESCRIPTION

[0022] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation methods of the present invention are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the directions or positional relationships indicated by "front", "rear", "up", "down", "left", "right", "vertical", "horizontal", "bottom", "inside", "inside", "outside", etc. are based on the directions or positional relationships shown in some of the drawings, and are constructed and operated in a specific direction. They are only for the convenience of describing the present technical solution, and do not indicate that the device or element referred to must have a specific direction, and therefore cannot be understood as a limitation to the present invention.

[0023] It should also be noted that, unless otherwise clearly specified and limited, the terms such as "installed", "connected", "connected", "fixed", "set" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. When an element is referred to as being "on" or "under" another element, the element can be "directly" or "indirectly" located on the other element, or there may be one or more intermediate elements. The terms "first", "second", etc. are only for the convenience of describing the present technical solution, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. 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 the specific circumstances.

[0024] In the following description, specific details such as specific system structures and technologies are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details that hinder the description of the present invention.

[0025] Figure 1The containment pressure relief filter device 1 in the first embodiment of the utility model is shown. The containment pressure relief filter device 1 is arranged in the containment 2 and connected to the outside of the containment 2 through a pipeline to prevent the leakage of radioactive gas while releasing pressure under accident conditions. The device includes a pressure relief pipeline 10 and a pre-filter bypass 20, wherein the outlet end of the pressure relief pipeline 10 and the outlet end of the pre-filter bypass 20 are connected (that is, the pressure relief pipeline 10 and the pre-filter bypass are arranged in parallel) to further improve the filtering capacity of the containment pressure relief filter device 1 and prevent the leakage of radioactive gas.

[0026] In some embodiments, a first filter 11 and a check valve 12 are provided on the pressure relief pipeline 10, wherein the first filter 11 is provided at the inlet end of the pressure relief pipeline 10 for filtering the gas in the containment shell 2, and the check valve 12 is provided at the outlet end of the first filter 11 for controlling the on / off of the pressure relief pipeline 10 so that the gas in the containment shell 2 is released as much as possible through the pre-filter bypass 20 to reduce the working pressure of the first filter 11.

[0027] Specifically, the check valve 12 is a swing check valve.

[0028] In some embodiments, the action setting value of the check valve 12 is 1.0 bar gauge pressure, that is, when the difference between the gas pressure in the containment shell 2 and the external atmospheric pressure is less than 1.0 bar gauge pressure, the check valve 12 controls the pressure relief pipeline 10 to be turned on, and the gas in the containment shell 2 flows through the first filter 11 for filtration; when the difference between the gas pressure in the containment shell 2 and the external atmospheric pressure is greater than 1.0 bar gauge pressure, the check valve 12 controls the pressure relief pipeline 10 to be closed, and the gas is depressurized through the pre-filtration bypass 20.

[0029] It should be understood that the action setting value of the check valve 12 can be flexibly selected according to specific circumstances.

[0030] In some embodiments, the check valve 12 may not be configured as a swing check valve, as long as it satisfies the requirement that the pre-filter bypass 20 is used first for pressure relief at the beginning of pressure relief, and then a control valve is used for pressure relief through the pressure relief pipeline 10.

[0031] In some embodiments, the action setting value of the check valve 12 may not be set to 1.0 bar gauge pressure. The specific action setting value may be flexibly set according to the specific conditions of the pressure relief pipeline 10 and the pre-filtration bypass 20 and the accident conditions of the containment 2.

[0032] In some embodiments, a second filter 21 is disposed on the pre-filter bypass 20 . The second filter 21 is disposed at the inlet end of the pre-filter bypass 20 and is used to filter radioactive substances in the gas flowing through the pre-filter bypass 20 .

[0033] In some embodiments, under the same conditions, the filtering pressure difference of the second filter 21 is greater than the filtering pressure difference of the first filter 11, so as to cooperate with the check valve 12 on the pressure relief pipeline 10 to ensure that in the initial stage of pressure relief, the high-pressure radioactive gas can reduce the radioactive content of the gas as much as possible under the action of the second filter 21.

[0034] It should be understood that the above-mentioned "under the same state" includes but is not limited to: the first filter 11 and the second filter 21 are in the same position in the containment (they cannot be exactly the same, it only means that compared with the huge containment, the distance between the two can be ignored), at the same time, working to the same extent (such as both are in a brand new state just put into use), with the same gas flow rate and pressure at the same position, etc.

[0035] In some embodiments, the containment pressure relief filtering device 1 also includes an output pipeline 30, which is passed through the containment 2 and is used to connect the external environment with the pressure relief pipeline 10 and the pre-filtration bypass 20. A third filter 31 and a valve 32 are provided on the output pipeline 30, wherein the third filter 31 is arranged at the outlet end of the output pipeline 30 as a second filtering barrier to once again filter the gas discharged from the first filter 11 or the second filter 21 after filtering, and the valve 32 is arranged at the inlet end of the third filter 31 to control the switch of the output pipeline 30.

[0036] Specifically, in this embodiment, the third filter 31 is a sand filter, and the valve 32 is a manual isolation valve.

[0037] In some embodiments, a penetration piece 33 is provided between the output pipeline 30 and the containment shell 2, and the penetration piece 33 is used to fix the output pipeline 30 on the containment shell 2 and seal the part where the output pipeline passes through the containment shell 2. Specifically, the penetration piece 33 has a certain pressure bearing capacity.

[0038] In some embodiments, the output pipeline 30 is connected to the pressure relief pipeline 10 and the pre-filtration bypass 20 via a connecting flange.

[0039] It should be noted that after a loss of coolant accident (LOCA) occurs, the radioactive particulate matter in the gas in the containment 2 will increase significantly due to the activation of the safety device. Therefore, the filter with a larger filtration pressure difference is prone to clogging after adsorbing radioactive particles, while the filter with a smaller filtration pressure difference will have a poor outgoing filtration effect and a low percentage of radioactive material filtration. Under the premise of the above-mentioned filtration pressure difference, when there is no check valve 12, most of the gas in the containment 2 will preferentially choose the first filter 11 to enter the containment pressure relief filter device 1, which is likely to cause leakage of radioactive particles, thereby increasing the burden of the third filter 31. If the radioactive energy stored in the third filter 31 is too high, it is possible that radioactive substances will be discharged into the external environment.

[0040] However, since the check valve 12 is provided on the pressure relief pipeline 10, the air pressure in the containment 2 is relatively high at the beginning, so that the gauge pressure measured by the check valve 12 is greater than the action setting value, and the pressure relief pipeline 10 cannot be conducted. Therefore, the gas in the containment 2 will preferentially select the second filter 21 to enter the containment pressure relief filter device 1. The second filter 21 can greatly absorb the radioactive substances in the exhaust gas, reduce the load of other filters, and thus reduce the radioactive substances discharged into the external environment. As the pressure relief proceeds, the second filter 21 is blocked or the action setting value measured by the check valve 12 is less than 1.0 bar gauge pressure. At this time, the pressure relief pipeline 10 is conducted, and the gas is filtered through the first filter 11. During the entire pressure relief process, the gas filtered by the first filter 11 or the second filter 21 flows to the third filter 31 of the output pipeline 30 for filtering again, and then discharged to the outside.

[0041] like Figure 2 As shown, the second embodiment of the utility model constructs a containment atmosphere monitoring system for monitoring the gas in the containment, and the containment atmosphere monitoring system includes a gas sampling monitoring system 3, an air pressure detection system 4 and a containment pressure relief filter device 1 under any of the above possible schemes.

[0042] The gas sampling monitoring system 3 is used to extract samples of the gas in the containment 2 and detect the pollutants in the samples to obtain the pollution conditions of the gas in the containment 2. The air pressure detection system 4 is used to detect the gas in the containment 2 to obtain the air pressure conditions of the gas in the containment 2. Finally, the operation of the containment pressure relief filter device 1 can be controlled according to the pollution conditions and air pressure conditions.

[0043] It can be understood that the above embodiments only express the preferred implementation methods of the utility model, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the utility model. It should be pointed out that, for ordinary technicians in this field, without departing from the concept of the utility model, the above-mentioned technical features can be freely combined, and several deformations and improvements can be made, which all belong to the protection scope of the utility model. Therefore, all equivalent changes and modifications made to the scope of the claims of the utility model should fall within the scope of the claims of the utility model.

Claims

1. A containment pressure relief filter device, characterized in that: The invention comprises a pressure relief pipeline (10) and a pre-filter bypass (20), wherein the pressure relief pipeline (10) is connected to an outlet end of the pre-filter bypass (20); a first filter (11) and a check valve (12) are arranged on the pressure relief pipeline (10), and a second filter (21) is arranged on the pre-filter bypass (20).

2. The containment pressure relief filter device according to claim 1, characterized in that: The check valve (12) comprises a swing check valve.

3. The containment pressure relief filter device according to claim 2, characterized in that: The action setting value of the check valve (12) is 1.0 bar gauge pressure.

4. The containment pressure relief filter device according to claim 1, characterized in that: The filtration pressure difference of the first filter (11) is smaller than that of the second filter (21).

5. The containment pressure relief filter device according to claim 1, characterized in that: The check valve (12) is arranged at the outlet end of the first filter (11).

6. The containment pressure relief filter device according to claim 1, characterized in that: The containment shell pressure relief filtering device further comprises an output pipeline (30), the outlet end of the pressure relief pipeline (10) and the outlet end of the pre-filter bypass (20) are both connected to the inlet end of the output pipeline (30), and the outlet end of the output pipeline (30) is arranged outside the containment shell (2); and a third filter (31) is arranged at the outlet end of the output pipeline (30).

7. The containment pressure relief filter device according to claim 6, characterized in that: The third filter (31) comprises a sand filter.

8. The containment pressure relief filter device according to claim 6, characterized in that: The output pipeline (30) is provided with a valve (32), and the valve (32) is arranged outside the containment shell (2).

9. The containment pressure relief filter device according to claim 6, characterized in that: The output pipeline (30) further comprises a penetration piece (33), and the penetration piece (33) is arranged on the containment shell (2).

10. A containment atmosphere monitoring system, characterized in that: It comprises the containment pressure relief filter device as described in any one of claims 1 to 9.

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