Portable helium lofting device for nuclear power plant

Abstract

The utility model discloses a portable helium lofting device for a nuclear power plant, which comprises a knapsack, a helium bottle arranged in the knapsack, an air entraining component connected with the helium bottle and a helium mass spectrometer leak detector used for detecting helium concentration, the air entraining assembly comprises a helium pressure reducing valve, a first connecting pipe, a control valve, a second connecting pipe and a nozzle which are sequentially connected in the airflow direction, the cross section area of the nozzle is gradually reduced in the airflow direction, and the input end of the helium pressure reducing valve is connected with the outlet end of the helium bottle. According to the portable helium lofting device for the nuclear power plant, helium can be accurately released in the leakage checking process of the vacuum boundary of the condenser, and under the condition that a suspected leakage point position exists in the leakage checking process and the helium bottle is inconvenient to convey through a trolley or a scaffold needs to be erected, an operator can directly carry the helium bottle through a backpack to carry out leakage checking operation; and the helium mass spectrometer leak detector is used for detection, so that the labor intensity of operators is reduced, and the leak detection efficiency and the accuracy of leak detection results are improved.

Description

Technical Field

[0001] The utility model relates to the field of helium leak detection in nuclear power plants, in particular to a portable helium sampling device for nuclear power plants. Background Technique

[0002] The condenser is one of the important auxiliary equipment in the power plant and has a great impact on the safe and economic operation of the entire power plant. One of the main functions of the condenser is to establish and maintain a certain vacuum at the exhaust port of the steam turbine. Due to the extremely high vacuum of the condenser and the large vacuum boundary range, it is inevitable for air to leak into the condenser. If the air leakage flow rate is too large, it will lead to the deterioration of the condenser vacuum and the increase of dissolved oxygen in the condensate water, which is not conducive to the unit output and the operation safety of the equipment.

[0003] When there is an air leak in the vacuum boundary of the condenser, helium leak detection is a conventional and effective method. In the actual leak detection process, sometimes due to the suspected leak point being too high, it is necessary to set up a scaffolding, which takes a long time. And sometimes the position of releasing helium is not accurate, resulting in missing the leak point. In addition, the helium-filled bag carried by the leak detection personnel is not pressure-bearing and has a small volume, and it needs to be refilled with helium again soon. The round-trip of the personnel to refill helium also wastes time. In summary, when detecting helium leaks in the vacuum boundary of the condenser, in order to improve the leak detection efficiency and release helium more accurately, a new tool needs to be developed. Content of the Utility Model

[0004] The technical problem to be solved by the utility model is to provide a portable helium sampling device for nuclear power plants.

[0005] The technical solution adopted by the utility model to solve its technical problems is: to construct a portable helium sampling device for nuclear power plants, which includes a backpack, a helium gas cylinder installed in the backpack, an air guiding component connected to the helium gas cylinder, and a helium mass spectrometer leak detector for detecting the helium concentration;

[0006] The air guiding component includes a helium pressure reducing valve, a first connecting pipe, a control valve, a second connecting pipe, and a nozzle connected in sequence along the air flow direction. The cross-sectional area of the nozzle gradually decreases along the air flow direction. The input end of the helium pressure reducing valve is connected to the outlet end of the helium gas cylinder.

[0007] In some embodiments, a buffer layer is provided in the backpack.

[0008] In some embodiments, the air guiding component further includes a pressure gauge connected to the first connecting pipe.

[0009] In some embodiments, the air guiding component further includes a flow meter connected to the second connecting pipe.

[0010] In some embodiments, the first connecting pipe is a plastic hose.

[0011] In some embodiments, the second connecting pipe is a stainless - steel corrugated hose or a plastic corrugated hose.

[0012] In some embodiments, the length of the second connecting pipe is 0.5 m, 1 m, 1.5 m or 2 m.

[0013] In some embodiments, the control valve is a needle valve.

[0014] In some embodiments, the capacity of the helium gas cylinder is 2 L or 4 L.

[0015] In some embodiments, the first connecting pipe is detachably connected to both the helium pressure reducing valve and the control valve;

[0016] The second connecting pipe is detachably connected to both the control valve and the nozzle.

[0017] Implementing the present utility model has the following beneficial effects: The portable helium gas sampling device for nuclear power plants can accurately release helium gas during the leak detection process of the condenser vacuum boundary. And when it is inconvenient to transport the helium gas cylinder by a trolley or it is necessary to erect a scaffolding at the suspected leak point during the leak detection process, the operator can directly carry the helium gas cylinder using a backpack for leak detection operations, and use a helium mass spectrometer leak detector for detection, reducing the labor intensity of the operator and improving the leak detection efficiency and the accuracy of the leak detection results. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the present utility model, the present utility model will be further described below in conjunction with the drawings and embodiments. It should be understood that the following drawings only show some embodiments of the present utility model, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other relevant drawings can also be obtained based on these drawings. In the drawings:

[0019] Figure 1 is the overall structural schematic diagram of the portable helium gas sampling device for nuclear power plants of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] In order to have a clearer understanding of the technical features, objectives, and effects of the present utility model, the specific implementation manners of the present utility model will now be described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientation or positional relationships indicated by "front", "rear", "upper", "lower", "left", "right", "longitudinal", "transverse", "vertical", "horizontal", "top", "bottom", "inner", "outer", "head", "tail", etc. are based on the orientation or positional relationships shown in the drawings and are constructed and operated in a specific orientation, and are only for the convenience of describing the present technical solution, rather than indicating that the device or element referred to must have a specific orientation. Therefore, it should not be construed as a limitation to the present utility model.

[0021] It should also be noted that, unless otherwise clearly specified and limited, terms such as "installation", "connection", "attachment", "fixation", "setting", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication 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 above the other element, or there may also be one or more intermediate elements. The terms "first", "second", "third", 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 quantity of the indicated technical features. Thus, the features defined with "first", "second", "third", etc. may explicitly or implicitly include one or more of such 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 specific circumstances.

[0022] Referring to Figure 1 , a portable helium gas sampling device for a nuclear power plant in some embodiments of the present utility model, which can be applied to the leak detection process of the condenser vacuum boundary. It includes a backpack 1, a helium gas cylinder 2 installed in the backpack 1, an air guiding assembly 3 connected to the helium gas cylinder 2, and a helium mass spectrometer leak detector for detecting the helium gas concentration. The air guiding assembly 3 includes a helium gas pressure reducing valve 31, a first connecting pipe 32, a control valve 33, a second connecting pipe 34, and a nozzle 35 connected in sequence along the gas flow direction. The input end of the helium gas pressure reducing valve 31 is connected to the outlet end of the helium gas cylinder 2. The cross-sectional area of the nozzle 35 gradually decreases along the gas flow direction, which can enhance the use effect of the helium gas ejected from the nozzle 35. The diameter of the end of the nozzle 35 where the helium gas is ejected is preferably 1 mm. In some other embodiments, the nozzle 35 can be adaptively replaced with a nozzle of other shapes according to the specific structural characteristics of the leak detection part.

[0023] Specifically, the backpack 1 can be a special loading backpack for helium gas cylinders, which is easy for operators to carry. When there is a suspected leak point during the leak detection process and it is inconvenient to transport the helium gas cylinder 2 by a trolley or a scaffolding needs to be erected, the operator can directly carry the helium gas cylinder 2 with the backpack 1 for leak detection operations. When leak detection such as the vacuum boundary of the condenser needs to be performed, the operator can carry the helium gas cylinder 2 by putting on the backpack 1. A buffer layer is provided inside the backpack 1, which can provide a buffering effect for the helium gas cylinder 2 during movement or use.

[0024] Among them, the capacity of the helium gas cylinder 2 is 2L or 4L, and it can be selected according to the actual requirements of on-site leak detection.

[0025] And the helium mass spectrometer leak detector is used to detect whether there is a leak in the vacuum boundary of the condenser. After helium gas is sprayed on a local area of the vacuum boundary of the condenser, if the helium mass spectrometer leak detector does not detect an increase in helium gas concentration, it can be excluded that there is no leak in this whole area. If there is a leak in this whole area, the helium mass spectrometer leak detector will react, so that the location of the leak area and the size of the gas leakage amount can be known.

[0026] In addition, the helium gas pressure regulator 31 is used to adjust the pressure when helium gas exits, and the control valve 33 is used to adjust the on-off when helium gas needs to be used. The control valve 33 is preferably a needle valve.

[0027] And the first connecting pipe 32 is a plastic hose, which is convenient for observation and connection. The first connecting pipe 32 is detachably connected to both the helium gas pressure regulator 31 and the control valve 33. Both ends of the first connecting pipe 32 can be connected to the helium gas pressure regulator 31 or the control valve 33 through a conversion joint. The conversion joint can be a 1 / 4-inch ferrule joint or a straight-through adapter, and can be selected according to the actual situation.

[0028] The second connecting pipe 34 is detachably connected to both the control valve 33 and the nozzle 35. The second connecting pipe 34 is a stainless steel corrugated hose or a plastic corrugated hose. The setting that the second connecting pipe 34 is a corrugated hose can make the second connecting pipe 34 relatively easy to rotate relative to the control valve 33, and at the same time the nozzle 35 is also easy to rotate. The orientation of the nozzle 35 can be adjusted according to different on-site operation requirements, increasing the adaptability of on-site leak detection work. In addition, the length of the second connecting pipe 34 is 0.5m, 1m, 1.5m or 2m, and it can be selected according to the actual requirements of on-site leak detection.

[0029] The air extraction assembly 3 further includes a pressure gauge 36 connected to the first connecting pipe 32, and the pressure gauge 36 is used to detect the helium gas pressure after being adjusted by the helium gas pressure regulator 31. The air extraction assembly 3 further includes a flow meter 37 connected to the second connecting pipe 34, and the flow meter 37 is used to measure the flow value of helium gas.

[0030] The specific application operation process of the portable helium sampling device for nuclear power plants is as follows:

[0031] 1. Assemble all the components of the portable helium sampling device for nuclear power plants. Close the helium pressure reducing valve 31 and the control valve 33 completely, and the whole is in a standby state. When it is necessary to check for leaks in the condenser vacuum boundary, etc., the operator puts on the backpack 1 and carries the helium gas cylinder 2 to the area where leaks need to be checked;

[0032] 2. When performing helium spraying for leak detection, two operators need to operate together. One operator slowly opens the helium pressure reducing valve 31, observes the reading of the pressure gauge 36, and controls the helium pressure reducing valve 31 so that the reading of the pressure gauge 36 is 0.1 - 0.2 MPa. The operator aims the nozzle 35 at the suspected leak point and appropriately opens the control valve 33 to spray helium;

[0033] 3. Use a helium mass spectrometer leak detector for detection.

[0034] It can be understood that the portable helium sampling device for nuclear power plants can accurately release helium during the leak detection process of the condenser vacuum boundary. And when it is inconvenient to transport the helium gas cylinder 2 by a trolley or it is necessary to erect a scaffolding at the suspected leak point during the leak detection process, the operator can directly carry the helium gas cylinder 2 using the backpack 1 for leak detection operations and use a helium mass spectrometer leak detector for detection, reducing the labor intensity of the operator and improving the leak detection efficiency and the accuracy of the leak detection results.

[0035] It can be understood that the above embodiments only represent the preferred implementation modes of the present invention, and the description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention; it should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, the above technical features can be freely combined, and several deformations and improvements can also be made, which all belong to the protection scope of the present invention; therefore, all equivalent transformations and modifications made to the scope of the claims of the present invention shall fall within the scope covered by the claims of the present invention.

Claims

1. A portable helium sampling device for a nuclear power plant, characterized in that: It comprises a backpack (1), a helium cylinder (2) installed in the backpack (1), an air induction component (3) connected to the helium cylinder (2), and a helium mass spectrometer leak detector for detecting helium concentration; The air bleed assembly (3) comprises a helium pressure reducing valve (31), a first connecting pipe (32), a control valve (33), a second connecting pipe (34) and a nozzle (35) which are sequentially connected along the airflow direction; the cross-sectional area of ​​the nozzle (35) gradually decreases along the airflow direction; and the input end of the helium pressure reducing valve (31) is connected to the outlet end of the helium cylinder (2).

2. The portable helium sampling device for nuclear power plants according to claim 1, characterized in that: A buffer layer is arranged inside the backpack (1).

3. The portable helium sampling device for nuclear power plants according to claim 1, characterized in that: The bleed air assembly (3) further comprises a pressure gauge (36) connected to the first connecting pipe (32).

4. The portable helium sampling device for nuclear power plants according to claim 1, characterized in that: The bleed air assembly (3) further comprises a flow meter (37) connected to the second connecting pipe (34).

5. The portable helium sampling device for nuclear power plants according to claim 1, characterized in that: The first connecting pipe (32) is a plastic hose.

6. The portable helium sampling device for nuclear power plants according to claim 1, characterized in that: The second connecting pipe (34) is a stainless steel corrugated hose or a plastic corrugated hose.

7. The portable helium sampling device for nuclear power plants according to claim 1, characterized in that: The length of the second connecting pipe (34) is 0.5 m, 1 m, 1.5 m or 2 m.

8. The portable helium sampling device for nuclear power plants according to claim 1, characterized in that: The control valve (33) is a needle valve.

9. The portable helium sampling device for nuclear power plants according to claim 1, characterized in that: The capacity of the helium cylinder (2) is 2L or 4L.

10. The portable helium sampling device for nuclear power plants according to claim 1, characterized in that: The first connecting pipe (32) is detachably connected to the helium pressure reducing valve (31) and the control valve (33); The second connecting pipe (34) is detachably connected to the control valve (33) and the nozzle (35).

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