Single-rod helium volume fraction online detection device

Abstract

The utility model relates to the technical field of nuclear fuel element manufacturing, and aims to solve the problem that the volume fraction of helium filled inside is abnormal in the single-rod hole plugging welding process. The utility model discloses a single-rod helium volume fraction on-line detection device which comprises a welding chamber, a welding gun is arranged in the welding chamber, a pressure reducing valve is connected outside the welding chamber, the pressure reducing valve is connected with a first exhaust valve, and a vacuumizing stop valve, a vacuum gauge, a helium filling stop valve and a pressure gauge are connected outside the welding chamber. According to the utility model, the stability of the volume fraction of helium in the single rod after hole plugging welding is ensured, and the qualification rate of subsequent finished products is improved.

Description

Technical Field

[0001] This utility model relates to the field of nuclear fuel element manufacturing technology, and in particular to an online detection device for the integral number of helium gas in a single rod. Background Technology

[0002] In the manufacturing process of nuclear fuel element fuel rods, plugging welding of fuel rod holes is often the last welding step in the production process. During welding, the workpiece is first inserted into the welding chamber, then clamped, and the entire welding chamber is sealed and evacuated. Once the vacuum level reaches the set value, helium is introduced into the welding chamber. When the internal pressure of the welding chamber reaches the required level, the gas introduction is stopped, and welding begins.

[0003] The primary purpose of filling individual fuel rods with helium is to prepare for subsequent helium leak detection. However, the current production process only uses the pressure in the welding chamber after filling as the evaluation criterion, making it impossible to measure the helium gas fraction inside the fuel rod. During mass production, only a portion of samples undergo destructive sampling, which cannot cover all products. If some fuel rods produced in the mass production do not meet the technical requirements for internal helium gas fraction, it will affect the helium leak detection results and the fuel rod's internal performance. Utility Model Content

[0004] The purpose of this invention is to provide an online detection device for the integral number of helium gas in a single rod, which solves the problem of abnormal integral number of helium gas filling the hole during the welding process of a single rod plugging hole.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] An online detection device for the integral number of a single-bar helium gas includes a welding chamber, in which a welding torch is installed; a pressure reducing valve is connected to the outside of the welding chamber, and the pressure reducing valve is connected to a first exhaust valve; a vacuum shut-off valve, a vacuum gauge, a helium filling shut-off valve, and a pressure gauge are also connected to the outside of the welding chamber.

[0007] In some embodiments, a helium gas detector is provided on the connecting pipeline between the pressure reducing valve and the first exhaust valve.

[0008] In some embodiments, a second exhaust valve is connected outside the welding chamber.

[0009] In some embodiments, the second exhaust valve is arranged on the same side as the inlet of the single rod.

[0010] In some embodiments, the single bar is clamped by clamping elements within the welding chamber.

[0011] In some embodiments, the single bar is positioned by a positioning element within the welding chamber.

[0012] In some embodiments, the single rod is coaxially arranged with the welding torch.

[0013] In some embodiments, the vacuum gauge is connected to the welding chamber via a vacuum shut-off valve.

[0014] In some embodiments, the vacuum shut-off valve, the vacuum gauge, the helium filling shut-off valve, and the pressure gauge are arranged on the same side of the welding chamber.

[0015] In some embodiments, the vacuum shut-off valve, the vacuum gauge, the helium filling shut-off valve, and the pressure gauge are arranged sequentially at intervals.

[0016] Compared with the prior art, the online detection device for single-bar helium gas integral number provided by this utility model has the following advantages:

[0017] This invention tests the internal helium gas volume of each single rod before welding, thereby ensuring that the helium gas volume of each product meets the technical requirements after helium filling.

[0018] This invention ensures the stability of the helium gas integral number inside the single rod after plugging welding, thereby improving the pass rate of subsequent finished products.

[0019] During the entire helium filling process in the welding chamber, the helium gas volume inside the welding chamber is detected through a dedicated gas path connected to the welding chamber. This ensures that the helium gas volume inside each fuel rod meets the required standards before welding, thus ensuring that each fuel rod meets the technical requirements without damaging the product. Attached Figure Description

[0020] To more clearly illustrate the technical solution of this utility model, the accompanying drawings used in the technical description will be briefly introduced below.

[0021] Figure 1 A schematic diagram of the structure of the online detection device for the single-bar helium gas integral number provided by this utility model.

[0022] Explanation of reference numerals in the attached figures:

[0023] 1. First exhaust valve; 2. Helium gas detector; 3. Pressure reducing valve; 4. Welding torch; 5. Single rod; 6. Second exhaust valve; 7. Vacuum shut-off valve; 8. Vacuum gauge shut-off valve; 9. Vacuum gauge; 10. Helium filling shut-off valve; 11. Pressure gauge. Detailed Implementation

[0024] The following detailed description provides further details on specific implementation methods.

[0025] This utility model provides an online detection device for the integral number of helium gas in a single rod, including four pipelines: a helium filling pipeline, a vacuum pumping pipeline, a helium gas integral number detection pipeline, and an exhaust pipeline, as well as three detection modules: a vacuum test gauge, a pressure test gauge, and a helium volume fraction test gauge.

[0026] Specifically, such as Figure 1 As shown, the testing device includes a first exhaust valve 1, a helium gas detector 2, a pressure reducing valve 3, a welding torch 4, a single rod 5, a second exhaust valve 6, a vacuum shut-off valve 7, a vacuum gauge shut-off valve 8, a vacuum gauge 9, a helium filling shut-off valve 10, a pressure gauge 11, and a welding chamber 12.

[0027] The first exhaust valve 1, helium detector 2, and pressure reducing valve 3 are located on the helium volume fraction detection pipeline. Pressure reducing valve 3 is connected to welding chamber 12 and is responsible for reducing the pressure of the gas in welding chamber 12 before sending it to helium detector 2. Pressure reducing valve 3 is located downstream of helium detector 2 and is responsible for venting the gas in the detection pipeline, forming a constant flow gas path. In other words, helium detector 2 is located on the connecting pipeline between the first exhaust valve 1 and pressure reducing valve 3.

[0028] In the vacuum pipeline, one end of the vacuum shut-off valve 7 is connected to the welding chamber 12, and the other end is connected to the vacuum pump, which is responsible for connecting and disconnecting the vacuum pump from the welding chamber 12.

[0029] In the helium filling pipeline, one end of the helium filling shut-off valve 10 is connected to the welding chamber 12, and the other end is connected to the helium gas source, which is responsible for connecting and blocking the helium gas source and the welding chamber 12.

[0030] In the exhaust pipeline, one end of the second exhaust valve 6 is connected to the welding chamber 12, and the other end is connected to the plant exhaust system, which is responsible for depressurizing the welding container and removing welding waste gas.

[0031] Optionally, the second exhaust valve 6 is located on the same side as the inlet of the single rod 5, and the second exhaust valve 6 is opposite to the welding torch 4.

[0032] Optionally, the first exhaust valve 1, helium detector 2, and pressure reducing valve 3 are located on the same side, and the vacuum shut-off valve 7, vacuum gauge shut-off valve 8, vacuum gauge 9, helium filling shut-off valve 10, and pressure gauge 11 are located on the same side, respectively arranged on opposite sides of the welding chamber 12.

[0033] Optionally, the vacuum shut-off valve 7, vacuum gauge 9, helium filling shut-off valve 10, and pressure gauge 11 are arranged sequentially and at intervals on the same side of the welding chamber 12.

[0034] The single rod 5 enters the welding chamber 12 and is clamped by the clamping device and positioned in the welding position by the positioning device. Both the clamping mechanism and the positioning structure are located inside the welding chamber 12.

[0035] The welding torch 4 is equipped with a tungsten electrode, and the welding torch 4 is arranged coaxially with the single rod 5.

[0036] Pressure gauge 11 is connected to the welding container and has a measurement range of -1MPa to 201MPa. It is used to measure the helium filling pressure of the welding chamber.

[0037] Vacuum gauge 9 is connected to the welding container through vacuum shut-off valve 8. The function of vacuum shut-off valve 8 is to isolate vacuum gauge 9 when the pressure in the welding chamber is too high. The function of vacuum gauge 9 is to measure the vacuum degree of the welding chamber when vacuuming.

[0038] The usage process of this utility model is as follows:

[0039] 1) After the single bar 5 enters, the workpiece is positioned in the welding position by the mechanical positioning of the internal structure of the tooling, and the workpiece is clamped.

[0040] 2) Close the first exhaust valve 1, pressure reducing valve 3, and helium filling shut-off valve 10, so that the entire welding chamber 12 is only connected to the vacuum module and vacuum gauge 9 to perform vacuuming operation. The vacuum gauge 9 monitors the vacuum value in real time. After the entire welding chamber is evacuated to below the set value, the vacuum pump and vacuum shut-off valve 8 are turned off.

[0041] 3) Open the helium charging shut-off valve 10 to carry out the helium charging operation. The pressure gauge 11 detects the pressure of the welding chamber. When the pressure of the welding chamber 12 reaches a slight positive pressure, open the pressure reducing valve 3. The first exhaust valve 1 ensures that the gas entering the helium gas detector 2 is in a normal pressure and constant flow state. The helium gas detector 2 detects the helium gas integral. When the helium gas integral meets the requirements, close the pressure reducing valve 3 and the first exhaust valve 1.

[0042] 4) Helium gas continues to enter the welding chamber 12 through the helium filling shut-off valve 10, and the pressure continues to rise. When the pressure rises to the specified pressure, the helium filling shut-off valve 10 is closed. The pressure gauge continues to monitor the pressure. When the pressure drop of the container is <10Pa within the specified time, the welding torch 4 is activated to perform the hole plugging welding operation.

[0043] 5) After the hole is plugged, open the second exhaust valve 6 to discharge the gas in the welding chamber 12 and perform a depressurization operation to reduce the pressure of the container to normal atmospheric pressure.

[0044] This invention provides an online detection device for detecting the volume fraction of helium gas filled before single-bar plugging welding. It mainly detects the helium filling status inside the welding chamber by adding a pressure reducing valve and a gas volume fraction meter to the dedicated gas line.

[0045] This invention establishes an online detection device for the integral number of helium gas in the welding chamber of a plugging welding machine, eliminating the reliance on the welding chamber pressure after helium filling as the sole criterion for whether welding should proceed.

[0046] This invention enables non-destructive testing of each product online, saving material costs and ensuring product quality.

[0047] This invention employs a multi-stage valve to isolate the detection instrument before and after vacuuming and high-pressure helium filling, thus preventing high pressure from damaging the vacuum instrument.

[0048] This invention employs decompression technology to reduce the pressure of the gas entering the helium volume fraction detector, while simultaneously using a constant flow state to stabilize the gas state.

[0049] The above description is only a specific embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present utility model should be included within the protection scope of the present utility model.

Claims

1. An online detection device for the integral number of a single-bar helium gas, characterized in that, It includes a welding chamber (12), in which a welding torch (4) is provided; a pressure reducing valve (3) is connected to the outside of the welding chamber (12), and the pressure reducing valve (3) is connected to a first exhaust valve (1); a vacuum shut-off valve (7), a vacuum gauge (9), a helium filling shut-off valve (10) and a pressure gauge (11) are connected to the outside of the welding chamber (12).

2. The online detection device for the integral number of a single-bar helium gas according to claim 1, characterized in that, A helium gas detector (2) is installed on the connecting pipeline between the pressure reducing valve (3) and the first exhaust valve (1).

3. The online detection device for the integral number of a single-bar helium gas according to claim 1, characterized in that, The welding chamber (12) is connected to a second exhaust valve (6).

4. The online detection device for the integral number of a single-bar helium gas according to claim 3, characterized in that, The second exhaust valve (6) and the inlet of the single rod (5) are arranged on the same side.

5. The online detection device for the integral number of a single-bar helium gas according to claim 1, characterized in that, The single bar (5) is clamped by the clamping member in the welding chamber (12).

6. The online detection device for the integral number of a single-bar helium gas according to claim 1, characterized in that, The single bar (5) is positioned by the positioning element in the welding chamber (12).

7. The online detection device for the integral number of a single-bar helium gas according to claim 6, characterized in that, The single rod (5) is coaxially arranged with the welding gun (4).

8. The online detection device for the integral number of a single-bar helium gas according to claim 1, characterized in that, The vacuum gauge (9) is connected to the welding chamber (12) via a vacuum shut-off valve (8).

9. The online detection device for the integral number of a single-bar helium gas according to claim 1, characterized in that, The vacuum shut-off valve (7), the vacuum gauge (9), the helium filling shut-off valve (10), and the pressure gauge (11) are arranged on the same side of the welding chamber (12).

10. The online detection device for the integral number of a single-bar helium gas according to claim 1, characterized in that, The vacuum shut-off valve (7), the vacuum gauge (9), the helium filling shut-off valve (10), and the pressure gauge (11) are arranged in sequence at intervals.

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