Special sample throwing helium cover for helium spraying leakage detection of nuclear power plant condenser

Abstract

The utility model discloses a sample helium cover special for helium spraying leakage detection of a nuclear power plant condenser, which comprises a cover body provided with an opening on one side so as to cover the condenser for helium feeding; the plurality of diffusion pipelines are symmetrically connected in a staggered manner and are fixedly connected with the cover body; a plurality of air outlet holes are formed in each diffusion pipeline in the same direction, and the multiple air outlet holes are formed at equal intervals to achieve uniform air outlet; the at least two gas charging connectors are symmetrically arranged on the diffusion pipeline, are respectively connected with the diffusion pipeline and are externally connected with a helium source; and the pressure monitoring joint is connected with the diffusion pipeline and is externally connected with a monitor so as to monitor the internal pressure of the diffusion pipeline. By increasing the number of the inflation connectors, the helium concentration in the leakage detection period can be increased, the distribution uniformity of helium in a helium cover area can be improved by arranging the air outlet holes at equal intervals, and therefore the sensitivity, effectiveness and accuracy of helium spraying leakage detection of the condenser are improved.

Description

Technical Field

[0001] This utility model relates to the field of condenser leak detection technology, and in particular to a special helium sampling hood for helium injection leak detection in nuclear power plant condensers. Background Technology

[0002] The secondary loop of a nuclear power plant has very high requirements for water quality. If the condenser heat exchanger titanium tubes or tube sheets leak, it will cause the secondary loop water quality to deteriorate, affecting the safety of important equipment such as the steam generator, and in severe cases, it may lead to a shutdown.

[0003] During the construction of the condenser, a leak detection device is installed to diagnose the specific water chamber where a leak has occurred. However, each water chamber has tens of thousands of heat exchange tubes. To accurately locate the specific leak location of the tube bundle or tube sheet sealing weld, it is necessary to isolate and vent the seawater water chamber side and maintain a vacuum in the condenser. Then, the leak point can be found by means of thin film covering method, flame method, helium detection method, etc. Among them, the most commonly used is helium injection leak detection method.

[0004] The condenser helium injection leak detection method involves dividing the water chamber tube sheet into several areas, using a helium hood to perform helium injection on the sealing welds and titanium tube bundles of each sub-area for leak detection. After finding the leak area, a smaller sampling device is used to detect leaks in the molecular area of ​​the leak area, gradually narrowing down the area until the leak location is finally precisely located.

[0005] Current helium injection leak detection methods involve designing an injection hood with an inflation connector and a diffusion line, with a 5mm vent directly below the line. Offline testing revealed that during inflation, the vent directly below the inflation connector produces a large volume of gas, which decreases significantly or even disappears towards the edges, indicating severe uneven gas distribution. Furthermore, to prevent helium from diffusing into the environment, an exhaust fan is used during leak detection. This creates a slight negative pressure inside the helium hood, causing helium to be drawn into nearby titanium tubes. Given the severe uneven gas distribution, helium may not reach the edges of the hood, leading to false positives in certain tube bundles. Utility Model Content

[0006] The technical problem to be solved by this utility model is to provide a special helium sampling hood for helium injection leak detection in nuclear power plant condensers.

[0007] The technical solution adopted by this utility model to solve its technical problem is: a special helium sampling hood for helium injection leak detection in nuclear power plant condensers, comprising:

[0008] The enclosure has an opening on one side to cover the condenser and release helium gas;

[0009] Several diffusion lines are symmetrically and interwoven and fixedly connected to the cover; each diffusion line has multiple air outlets facing the opening side, and the multiple air outlets are equally spaced to achieve uniform air output;

[0010] At least two inflation connectors are provided, which are symmetrically arranged on the diffusion pipeline and connected to the diffusion pipeline and an external helium source, respectively.

[0011] A pressure monitoring connector is connected to the diffusion line and an external monitor is connected to monitor the internal pressure of the diffusion line.

[0012] In some embodiments, the plurality of diffusion lines include a plurality of horizontal pipes and at least two vertical pipes, each of the horizontal pipes being connected to the two vertical pipes respectively and fixedly connected to the cover.

[0013] At least two of the inflation connectors are symmetrically connected to the two horizontal tubes.

[0014] In some embodiments, the plurality of diffusion lines further include a plurality of tees and / or a plurality of four-way connectors, wherein the horizontal pipe and the vertical pipe are connected by tees or four-way connectors.

[0015] In some embodiments, a plurality of air outlets are equally spaced along the length of the horizontal tube, and the plurality of air outlets face the length of the vertical tube.

[0016] In some embodiments, the cover includes side walls and a back wall;

[0017] The diffusion line is fixedly connected to the side wall and is also fixedly connected to the back wall via at least two inflation connectors and the pressure monitoring connector.

[0018] In some embodiments, the back wall is provided with a monitoring through hole and at least two inflation through holes;

[0019] The inflation connector passes through the inflation hole and is exposed outside the cover, and is sealed to the edge of the inflation hole; the pressure monitoring connector passes through the monitoring hole and is exposed outside the cover, and is sealed to the edge of the monitoring hole.

[0020] In some embodiments, a plurality of handles are also included, which are symmetrically connected to the back wall.

[0021] In some embodiments, the distance between two adjacent air outlets on the same diffusion pipeline is 15mm-20mm.

[0022] In some embodiments, the diameter of each of the vent holes is 1.5mm-2mm.

[0023] In some embodiments, the cover is a cuboid structure with an open bottom, the length of the cover is 100mm-1040mm, the width of the cover is 100mm-420mm, and the height of the cover is 50mm-100mm.

[0024] By implementing this utility model, the following beneficial effects can be achieved:

[0025] This utility model discloses a helium sampling hood specifically designed for helium injection leak detection in nuclear power plant condensers. It includes: a hood body with an opening on one side for covering the condenser and injecting helium gas; several diffusion lines symmetrically and interlaced, connected and fixedly connected to the hood body; each diffusion line having multiple outlet holes facing the opening, with the outlet holes evenly spaced to achieve uniform gas output; at least two filling connectors symmetrically positioned on the diffusion lines and connected to both the diffusion lines and an external helium gas source; and a pressure monitoring connector connected to the diffusion lines and connected to an external monitor to monitor the internal pressure of the diffusion lines. By increasing the number of filling connectors, the helium concentration during leak detection can be increased. The evenly spaced outlet holes improve the uniformity of helium distribution within the hood area, thereby enhancing the sensitivity, effectiveness, and accuracy of condenser helium injection leak detection. Attached Figure Description

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0027] Figure 1 This is a schematic diagram of the structure of a special helium sampling hood for helium injection leak detection in nuclear power plant condensers, according to one embodiment of this utility model.

[0028] Figure 2 yes Figure 1 A schematic diagram of the structure of the inner cover. Detailed Implementation

[0029] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0030] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0031] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0032] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or a chemical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0033] See Figure 1 and Figure 2 One embodiment of this utility model discloses a special helium sampling hood for helium injection leak detection in nuclear power plant condensers, comprising a hood body 1, several diffusion lines, at least two gas filling connectors 3, and a pressure monitoring connector 4. The hood body 1 has an opening on one side to cover the condenser and release helium gas. Several diffusion lines are symmetrically and alternately connected and fixedly connected to the hood body 1. Each diffusion line has multiple gas outlets facing the same direction, and the multiple gas outlets are evenly spaced to achieve uniform gas release. Two gas filling connectors 3 are symmetrically arranged on the diffusion lines and are respectively connected to the diffusion lines and to an external helium gas source. The pressure monitoring connector 4 is connected to the diffusion lines and to an external monitor to monitor the internal pressure of the diffusion lines.

[0034] Understandably, the helium sampling hood for helium injection leak detection in nuclear power plant condensers of this utility model can be used to perform helium injection leak detection on the condenser side of the seawater chamber when a seawater leak is detected in the secondary loop of a nuclear power plant. The hood body 1 is made of acrylic material and is transparent and visible. Considering that the helium hood can enter the Φ500mm manhole of the water chamber, and taking into account factors such as the on-site operating space and the arrangement shape of the titanium tube bundle, the hood body 1 is designed as a cuboid structure with an open bottom. The length of the hood body 1 is 100mm-1040mm, for example, 100mm, 500mm, 900mm, 1040mm, etc. The width of the hood body 1 is 100mm-420mm, for example, 100mm, 200mm, 400mm, 420mm, etc. The height of the hood body 1 is 50mm-100mm, for example, 50mm, 60mm, 80mm, 100mm, etc. In some embodiments, the maximum dimensions of the cover 1 are 1040mm in length, 420mm in width, and 100mm in height, respectively. This maximizes the coverage area of ​​the cover 1 while ensuring convenient operation on site, reducing the number of partitions and improving leak detection efficiency.

[0035] The spacing between adjacent vents on the same diffusion line is 15mm-20mm, such as 15mm, 17mm, 19mm, 20mm, etc. The diameter of each vent is 1.5mm-2mm, such as 1.5mm, 1.7mm, 1.9mm, 2.0mm, etc. Properly setting the spacing and diameter of the vents can improve the uniformity of helium distribution within the enclosure 1 area, ensuring that helium reaches all areas around the perimeter of enclosure 1 and preventing false positives.

[0036] In some embodiments, the diffusion lines include multiple horizontal pipes 21 and at least two vertical pipes 22, each horizontal pipe 21 being connected to one of the two vertical pipes 22 and fixedly connected to the housing 1. At least two inflation connectors 3 are symmetrically connected to the two horizontal pipes 21. For example, in use, the two inflation connectors 3 are connected to two helium cylinders to form two inflation lines. During leak detection, both lines are simultaneously filled with helium, increasing the helium flow rate and concentration, which improves leak detection sensitivity. Preferably, the diffusion lines are arranged uniformly in a grid pattern to ensure that the area covered by each outlet pipe and each inflation port remains substantially equal. The horizontal pipes 21 and vertical pipes 22 are both PVC pipes. Both ends of the horizontal pipes 21 are plugged with caps to prevent leakage.

[0037] Understandably, the horizontal and vertical directions of the horizontal tube 21 and vertical tube 22 in this utility model do not represent actual orientations. For ease of distinction, the horizontal tube 21 and vertical tube 22 are based on... Figure 1 and Figure 2 The diffusion pipelines are named according to their orientation; those distributed laterally are called horizontal pipes 21, and those distributed longitudinally are called vertical pipes 22. In some other embodiments, the horizontal pipes 21 and vertical pipes 22 can be distinguished according to their actual positions. This utility model restricts the actual directions of the horizontal pipes 21 and vertical pipes 22.

[0038] In some embodiments, the diffusion lines further include multiple tees and / or multiple four-way connectors, with the horizontal pipe 21 and the vertical pipe 22 connected via tees or four-way connectors. For example, the outer horizontal pipe 21 is connected to the vertical pipe 22 via a tee, and the inner horizontal pipe 21 is connected to the vertical pipe 22 via a four-way connector.

[0039] In some embodiments, a plurality of air outlets are equally spaced along the length of the horizontal tube 21, and the plurality of air outlets all face the length of the vertical tube 22. See [reference needed]. Figure 1 Multiple air vents can be arranged to face forward or backward together.

[0040] In some embodiments, the pressure monitoring connector 4 is located on the horizontal pipe 21 between the two inflation connectors 3 and is connected to an external pressure gauge for pressure detection. When adjusting the exhaust fan airflow, the pressure monitoring ensures that the airflow is adjusted to a slightly negative pressure state in the hood 1. This ensures that the gas flow rate in the titanium tubes of the condenser is not too fast, increasing the residence time of helium in the tube bundle of the condenser, and also prevents misjudgment of potential leak points caused by helium overflow.

[0041] like Figure 2 As shown, in some embodiments, the cover 1 includes a side wall 11 and a back wall 12, with the back wall 12 facing away from the opening. A diffuser line is fixedly connected to the side wall 11 and to the back wall 12 via at least two inflation connectors 3 and a pressure monitoring connector 4. For example, the diffuser line can be fixed to the side wall 11 by its own elasticity or by adhesive bonding. It is further secured by the inflation connectors 3 and the pressure monitoring connectors 4.

[0042] In some embodiments, the back wall 12 has a monitoring through-hole 13 and at least two inflation through-holes 14. An inflation connector 3 passes through the inflation through-hole 14 and is exposed outside the housing 1, and is sealed to the edge of the inflation through-hole 14. A pressure monitoring connector 4 passes through the monitoring through-hole 13 and is exposed outside the housing 1, and is sealed to the edge of the monitoring through-hole 13. Preferably, the monitoring through-hole 13 and the two inflation through-holes 14 are each approximately 20 mm in diameter, and the back wall 12 and the diffusion line are assembled together using 1 / 4 to 1 / 2 NPT connectors and gaskets, respectively.

[0043] In some embodiments, a plurality of handles 5 are also included, which are symmetrically connected to the back wall 12. For example, two handles 5 are symmetrically arranged to facilitate on-site movement and operation.

[0044] By implementing this utility model, the following beneficial effects can be achieved:

[0045] This invention relates to a helium sampling hood specifically designed for helium injection leak detection in nuclear power plant condensers. By increasing the number of filling connectors (3), the helium concentration during leak detection can be increased, significantly improving the sensitivity for detecting minor leaks in the condenser. The evenly spaced outlet holes enhance the uniformity of helium distribution within the hood area, completely eliminating false positives and false negatives, ensuring the validity and reliability of leak detection results, improving the level of leak detection and repair in condensers, and contributing to safe power plant production.

[0046] It is understood that the above embodiments only illustrate preferred embodiments of the present utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present utility model patent. It should be noted that for those skilled in the art, without departing from the concept of the present utility model, the above embodiments or technical features can be freely combined, and several modifications and improvements can be made. These all fall within the protection scope of the present utility model, that is, the embodiments described "in some embodiments" can be freely combined with any of the embodiments above and below. Therefore, all equivalent transformations and modifications made within the scope of the claims of the present utility model should fall within the coverage of the claims of the present utility model.

Claims

1. A special-purpose helium injection cover for a nuclear power plant condenser helium injection leak detection, characterized in that, include: The cover (1) has an opening on one side to cover the condenser and release helium gas; Several diffusion lines are symmetrically and interwoven and fixedly connected to the cover (1); each diffusion line has multiple air outlets facing the same direction, and the multiple air outlets are equally spaced to achieve uniform air output; At least two inflation connectors (3) are provided, the two inflation connectors (3) are symmetrically arranged on the diffusion pipeline and are respectively connected to the diffusion pipeline and an external helium source; Pressure monitoring connector (4) is connected to the diffusion line and an external monitor is connected to monitor the internal pressure of the diffusion line.

2. The special helium injection cover for the nuclear power plant condenser helium injection leak detection according to claim 1, characterized in that, The diffusion lines include multiple horizontal pipes (21) and at least two vertical pipes (22), each of the horizontal pipes (21) being connected to the two vertical pipes (22) respectively and fixedly connected to the cover (1); At least two of the inflation connectors (3) are symmetrically connected to the two horizontal pipes (21).

3. The special helium injection cover for the nuclear power plant condenser helium injection leak detection according to claim 2, characterized in that, Several of the diffusion lines also include multiple tees and / or multiple fours, with the horizontal pipe (21) and the vertical pipe (22) connected by tees or fours.

4. The special helium injection cover for the nuclear power plant condenser helium injection leak detection according to claim 2, characterized in that, The plurality of air outlets are equally spaced along the length of the horizontal tube (21), and the plurality of air outlets face the length of the vertical tube (22).

5. The special helium injection cover for the nuclear power plant condenser helium injection leak detection according to claim 1, characterized in that, The cover (1) includes a side wall (11) and a back wall (12); The diffusion line is fixedly connected to the side wall (11) and fixedly connected to the back wall (12) through at least two air inflators (3) and the pressure monitoring inflator (4).

6. The special helium injection cover for the nuclear power plant condenser helium injection leak detection according to claim 5, characterized in that, The back wall (12) is provided with a monitoring through hole (13) and at least two inflation through holes (14); The inflation connector (3) passes through the inflation through hole (14) and is exposed outside the cover (1), and is sealed to the edge of the inflation through hole (14); the pressure monitoring connector (4) passes through the monitoring through hole (13) and is exposed outside the cover (1), and is sealed to the edge of the monitoring through hole (13).

7. The special helium sampling hood for helium injection leak detection in nuclear power plant condensers according to claim 5, characterized in that, It also includes several handles (5), which are symmetrically connected to the back wall (12).

8. The special helium injection cover for the nuclear power plant condenser helium injection leak detection according to any one of claims 1-7, characterized in that, The distance between two adjacent air outlets on the same diffusion pipeline is 15mm-20mm.

9. The special helium injection cover for the nuclear power plant condenser helium injection leak detection according to any one of claims 1-7, characterized in that, The diameter of each of the vent holes is 1.5mm-2mm.

10. The special helium injection cover for the nuclear power plant condenser helium injection leak detection according to any one of claims 1-7, characterized in that, The cover (1) is a cuboid structure with an open bottom. The length of the cover (1) is 100mm-1040mm, the width of the cover (1) is 100mm-420mm, and the height of the cover (1) is 50mm-100mm.

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