A nuclear condenser air in-leakage tracer gas release device

Abstract

The application discloses a nuclear condenser air internal leakage tracer gas releasing device, which comprises a shell, characterized in that the device further comprises: a gas storage unit installed in the shell and used for storing the tracer gas; a gas pressure reducing unit installed in the shell and located downstream of the gas storage unit, which is used for reducing the pressure of the tracer gas sent by the gas storage unit to a required pressure value; a gas adjusting unit installed in the shell and located downstream of the gas pressure reducing unit, which is used for adjusting the pressure of the tracer gas so as to control the flow of the tracer gas; and a gas mixing unit installed in the shell and located downstream of the gas adjusting unit, which is used for mixing the tracer gas with air and adjusting the mixed concentration of the tracer gas. The application can meet the requirements of the tracer gas concentration, pressure adjustment and portability of the device in the application of the tracer gas leakage detection method of the nuclear condenser air internal leakage, and realizes the detection of the distributed discrete areas to be detected of the nuclear condenser one by one.

Description

Technical Field

[0001] The invention belongs to the field of nuclear power detection equipment, and in particular relates to a nuclear condenser air leakage tracer gas release device. Background Art

[0002] The condenser is an important cooling device in the thermal cycle of a nuclear power plant. The normal operation of the condenser establishes and maintains a vacuum at the turbine outlet through heat exchange with cooling water, and condenses the turbine exhaust steam into water as secondary circuit feed water, completing the cycle. The boundary integrity requirements of the condenser are high, mainly including the sealing of components such as the heat transfer tube bundle, flanges, and cover plates. Good condenser sealing can reduce the exhaust temperature and pressure of the turbine and improve the thermal cycle efficiency. An important aspect of condenser sealing failure is the entry of air into the vacuum environment on the condenser shell side through sealing connections such as flanges, cover plates, and expansion joints, resulting in a decrease in vacuum, an increase in back pressure, and an increase in the oxygen content of the condensate. This in turn reduces the turbine output and exacerbates corrosion of secondary circuit equipment, affecting the safe and economical operation of the nuclear power plant.

[0003] To address the problem of air leaking into the condenser shell through sealing connections (hereinafter referred to as air internal leakage), tracer gas leak detection is primarily used to locate these potentially leaking sealing connections. The leak detection principle involves applying a tracer gas to suspected areas of sealing connections, such as the condenser flange, while the condenser shell is under vacuum. If a leak is detected in this area, the shell vacuum will draw some of the tracer gas through the leak and into the shell. This gas, along with other non-condensable gases, is then pumped out through the condenser vacuum system. A tracer gas leak detector probe is connected to the vacuum system outlet to measure the tracer gas concentration and determine the leak status.

[0004] The condenser system is huge, and there are many and widely distributed sealing connection components. In the existing tracer gas leak detection method, the inspector usually fixes a tracer gas cylinder near the sealing connection component, uses a pressure reducing valve to reduce the pressure of the gas, and uses a gas pipe of appropriate length to pull the tracer gas to the position to be detected, and aligns the end of the gas pipe with the position to be detected to release the tracer gas. After completing the leak detection at a certain location, the gas cylinder, pressure reducing valve, and gas pipe are removed and moved to the next position to be detected. The gas cylinder, pressure reducing valve, and gas pipe are reconnected to perform the test. As shown in the patent application with publication number: CN203881678U, the above method has many problems during the detection execution, such as the tracer gas pressure and concentration cannot be adjusted, the residual tracer gas inside the gas pipe is diffused when the gas pipe line is removed, causing the environmental background to rise, and the detection positions are scattered, requiring frequent movement of gas cylinders and gas pipes. Summary of the Invention

[0005] The purpose of the present invention is to provide a nuclear condenser air leakage tracer gas release device that meets the requirements of tracer gas concentration, pressure adjustment and device portability.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solution: a nuclear condenser air leakage tracer gas release device, which includes a housing, characterized in that the device also includes:

[0007] a gas storage unit installed in the housing and used to store tracer gas;

[0008] a gas decompression unit installed in the housing and located downstream of the gas storage unit, and used to reduce the pressure of the tracer gas delivered by the gas storage unit to a required pressure value;

[0009] a gas regulating unit installed in the housing and located downstream of the gas decompression unit, and used to regulate the tracer gas pressure, thereby controlling the tracer gas flow;

[0010] The gas mixing unit is installed in the housing and located downstream of the gas regulating unit, and is used for mixing the tracer gas with air and regulating the mixed concentration of the tracer gas.

[0011] Optimally, the device further comprises a display unit for displaying tracer gas flow rate and concentration information.

[0012] Optimally, the device further includes a power supply unit for supplying power to the gas decompression unit, the gas regulating unit, and the gas mixing unit.

[0013] Optimally, the device further comprises a gas check unit for preventing the backflow or leakage of high-pressure gas that is filled into the device from the outside and merges with the tracer gas. The gas check unit, the gas decompression unit and the gas storage unit are respectively connected to the three-way valve.

[0014] Optimally, the gas storage unit includes a high-pressure gas cylinder.

[0015] Optimized, the gas decompression unit includes a pressure reducing valve, a pressure gauge and a rotating head. The pressure gauge is installed on the shell and is located outside the shell. It is communicated with the pressure reducing valve. The rotating head for adjusting the outlet pressure of the pressure reducing valve is installed on the pressure reducing valve.

[0016] Optimally, the gas regulating unit includes a gas flow meter and a gas regulating valve assembly. The gas regulating valve assembly is fixed in the shell, one end of which is connected to the gas decompression unit through a first bend pipe, and the other end is connected to the flow meter through a second bend pipe.

[0017] Optimally, the gas mixing unit includes a micro pneumatic pump and a confluence component, and the confluence component, the micro pneumatic pump and the flow meter are respectively connected to the three ports of the fourth elbow of the tee.

[0018] Preferably, the housing includes a first housing and a second housing.

[0019] Optimized, the device also includes a spray gun nozzle, a spray gun nozzle sleeve, and a spray gun nozzle bracket arranged on the shell, the spray gun nozzle bracket is installed in the shell, one end of the spray gun nozzle is connected to the gas mixing unit through the spray gun nozzle sleeve, and the end is passed through the spray gun nozzle sleeve and the spray gun nozzle bracket, and the other end of the spray gun nozzle extends out of the shell.

[0020] The beneficial effects of the present invention are that the present invention can meet the requirements of tracer gas concentration, pressure regulation and device portability in the application of nuclear condenser air leakage tracer gas leak detection method, and realize the detection of discrete areas to be detected in the nuclear condenser one by one. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a three-dimensional diagram of the device;

[0022] Figure 2 is a schematic diagram of the internal structure of the device;

[0023] Among them: 1. First gas cylinder bracket; 2. First shell; 3. High-pressure gas cylinder; 4. Second gas cylinder bracket; 5. First straight pipe; 6. T-joint; 7. High-pressure quick connector; 8. First charging bracket; 9. Check valve; 10. Second charging bracket; 11. Second straight pipe; 12. Power display module; 13. Pressure reducing valve; 14. Pressure gauge; 15. First elbow; 16. Merger bracket; 17. Merger assembly; 18. Spray gun nozzle; 19. Spray gun nozzle sleeve; 20. Spray gun nozzle bracket; 21. Fourth elbow; 22. Micro pneumatic pump; 23. L-shaped bracket; 24. Second elbow; 25. Gas regulating valve assembly; 26. Shell support column; 27. Flow meter; 28. LCD touch screen; 29. ​​Battery pack; 30. Third elbow; 31. Rotating head; 32. Second shell; 33. Power switch; 34. Bolt hole. DETAILED DESCRIPTION

[0024] The present invention is described in detail below with reference to the embodiments shown in the accompanying drawings:

[0025] like Figure 1-2 As shown, the nuclear condenser air leakage tracer gas release device includes:

[0026] The spray gun includes a nozzle; a housing; a gas storage unit installed within the housing and used to store tracer gas; a gas pressure reduction unit installed within the housing and located downstream of the gas storage unit, used to reduce the pressure of the tracer gas delivered by the gas storage unit to the required value; a gas regulating unit installed within the housing and located downstream of the gas pressure reduction unit, used to regulate the tracer gas pressure and thereby control the tracer gas flow; and a gas mixing unit installed within the housing and located downstream of the gas regulating unit, used to mix the tracer gas with air and adjust the tracer gas concentration. The tracer gas is sulfur hexafluoride.

[0027] Specifically:

[0028] The first shell 2 and the second shell 32 are sealed together by screws to form an entire shell shaped like a gun.

[0029] The gas storage unit consists of a first gas cylinder holder 1, a high-pressure gas cylinder 3, and a second gas cylinder holder 4. The high-pressure gas cylinder 3 is secured to the interior of the housing's handle by the first and second gas cylinder holders 1 and 4. The gas storage unit primarily stores tracer gas, such as sulfur hexafluoride, providing the tracer gas source required for leak detection.

[0030] The gas check unit consists of a high-pressure quick connector 7, a first pressure-charging bracket 8, and a check valve 9. The check valve 9 is sealed to the high-pressure quick connector 7 and secured to the rear end of the housing via the first pressure-charging bracket 8. The gas check unit's primary function is to prevent the backflow or leakage of high-pressure gas introduced into the device.

[0031] The gas decompression unit consists of a pressure reducing valve 13, a pressure gauge 14, and a rotating head 31. The pressure gauge 14 is externally mounted on the housing and communicates with the pressure reducing valve 13. The rotating head 31 is mounted on the pressure reducing valve 13 and is used to adjust the outlet pressure of the pressure reducing valve 13. The gas decompression unit's primary function is to reduce pressure, reducing the tracer gas pressure at the outlet of the high-pressure gas cylinder 3 to approximately 0.5 MPa, facilitating subsequent gas pressure and flow rate adjustments.

[0032] The gas storage unit, gas check unit, and gas pressure reducing unit are sealed and connected via a three-way joint 6. The port of the high-pressure gas cylinder 3 of the gas storage unit is connected to one end of the three-way joint 6 via a first straight pipe 5; the port of the check valve 9 of the gas check unit is connected to one end of the three-way joint 6; and the high-pressure side port of the pressure reducing valve 13 of the gas pressure reducing unit is connected to one end of the three-way joint 6 via a second straight pipe 11.

[0033] The gas regulating unit consists of a flowmeter 27 and a gas regulating valve assembly 25. The gas regulating valve assembly 25 has a built-in gas controller and is fixed to the first housing 2 of the device. One end of the gas regulating valve assembly 25 is connected to the gas decompression unit via a first elbow 15, and the other end is connected to the flowmeter 27 via a second elbow 24. The gas regulating unit's primary function is to adjust the tracer gas pressure through the built-in controller, thereby controlling the gas flow rate.

[0034] The gas mixing unit consists of a micro-pneumatic pump 22 and a confluence assembly 17. The confluence assembly 17 is secured to the front end of the housing via a confluence bracket 16 and a spray gun nozzle bracket 20. The micro-pneumatic pump 22 is secured to the interior of the housing via an L-shaped bracket 23. The air inlet of the confluence assembly 17 is connected to the micro-pneumatic pump 22 via a three-way fourth elbow 21. The third port of the fourth elbow 21 is connected to a flowmeter 27. The air outlet of the confluence assembly 17 is connected to the spray gun nozzle 18 via a spray gun nozzle sleeve 19. The main function of the gas mixing unit is to mix the tracer gas with air and to control and adjust the tracer gas mixture concentration via the micro-pneumatic pump 22.

[0035] The power supply unit consists of a battery pack 29 and a power switch 33. The battery pack 29 is secured within the device's first housing 2, while the power switch 33 is embedded within the device's second housing 32. The power supply unit primarily provides power to components such as the micro-pneumatic pump 22, the gas regulating valve assembly 25, the flow confluence assembly 17, the power display module 12, and the LCD touch screen 28.

[0036] The display unit consists of a power display module 12 and an LCD touch screen 28. These modules are embedded in the device's second housing 32. The power display module 12 is used to display the battery pack 29's power level; the LCD touch screen 28 is used to set and view information such as gas concentration and flow.

[0037] The spray gun nozzle 18 is made of carbon fiber material and is a combination of a series of round tubes of different diameters and lengths. It can be extended to the required specific length, making it convenient for the inspector to apply the tracer gas to the area to be inspected at close range.

[0038] The implementation of the various functions of this device includes the following steps:

[0039] Step 1: Start the device and wait for all components to warm up.

[0040] Step 2: Use the LCD touch screen buttons to set the expected sulfur hexafluoride concentration and flow rate in the mixed gas.

[0041] Step 3: Turn on the switch of the high-pressure gas cylinder 3. The tracer gas flows from the outlet of the high-pressure gas cylinder 3 through the first straight pipe 5 into the three-way joint 6. The tracer gas then flows through the second straight pipe 11 into the high-pressure side inlet of the pressure reducing valve 13. During this process, the check valve 9 prevents gas backflow.

[0042] Step 4: Use the rotary head 31 to adjust the tracer gas pressure to about 0.5 MPa. The decompressed gas passes through the first elbow 15, the second elbow 24, the gas regulating valve assembly 25, and the flow meter 27 from the low-pressure side outlet of the pressure reducing valve 13.

[0043] Step 5: The flow meter 27 feeds back the measured flow value data to the gas regulating valve assembly 25 and displays it on the LCD touch screen 28.

[0044] Step 6: The gas regulating valve assembly 25 adjusts the tracer gas flow rate to a preset value according to the feedback flow rate value. The LCD touch screen 28 displays the flow rate change in real time and sets the maximum injection flow rate limit of sulfur hexafluoride to 10 L / min.

[0045] Step 7: The air is collected and pressurized by the micro pneumatic pump 22 and enters the confluence component 17.

[0046] Step 8: The tracer gas enters the confluence assembly 17 through the fourth elbow 21 and is fully mixed with the air.

[0047] Step 9: The built-in infrared sensor for sulfur hexafluoride concentration feeds back the detected concentration value to the built-in controller and LCD touch screen 28 of the confluence component 17. After calculation by the PID algorithm, the opening of the sulfur hexafluoride regulating valve 25 is controlled until the concentration of the mixed gas reaches the preset value. The PID control algorithm is a control algorithm that combines the three links of proportional, integral and differential.

[0048] Step 10: When the mixed gas flow rate and concentration are stably output and reach the preset value, the spray gun nozzle 18 is extended and retracted to an appropriate length, and the inspector places the spray gun nozzle 18 close to the area to be inspected of the nuclear condenser to release the mixed tracer gas.

[0049] Step 11: Determine the leakage situation based on the measurement signal of the leak detector arranged at the outlet of the nuclear condenser vacuum system.

[0050] Step 12: Wait for the leak detector signal to return to the background signal, retract the spray gun nozzle 18, and carry the release device to the next area to be inspected until the inspection of all areas to be inspected is completed.

[0051] The above embodiments are intended only to illustrate the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the present invention and implement it accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made in accordance with the spirit of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A method for detecting an air leakage tracer gas release device for a nuclear condenser, the device comprising a housing and further comprising: a gas storage unit installed in the housing and used to store tracer gas, the gas storage unit comprising a high-pressure gas cylinder, which is fixed to the interior of the handle of the housing via a first gas cylinder bracket and a second gas cylinder bracket; a gas decompression unit installed in the housing and located downstream of the gas storage unit, and used to reduce the pressure of the tracer gas delivered by the gas storage unit to a required pressure value; a gas regulating unit installed in the housing and located downstream of the gas decompression unit, and used to regulate the tracer gas pressure, thereby controlling the tracer gas flow; a gas mixing unit installed in the housing and located downstream of the gas regulating unit, for mixing the tracer gas with air and regulating the tracer gas mixed concentration; The gas mixing unit includes a micro pneumatic pump and a confluence assembly, wherein the confluence assembly, the micro pneumatic pump, and the flow meter are respectively connected to the three ports of the fourth elbow of the tee; the high-pressure gas cylinder port of the gas storage unit is connected to one end of the tee joint through the first straight pipe, the air inlet of the confluence assembly is connected to the micro pneumatic pump through the fourth elbow of the tee, the third port of the fourth elbow is connected to the flow meter, and the air outlet of the confluence assembly is connected to the spray gun nozzle through the spray gun nozzle sleeve; It is characterized in that the detection method comprises the following steps: Step 1: Start the device and wait for all components to be preheated; Step 2: Use the LCD touch screen buttons to set the expected sulfur hexafluoride concentration and flow rate in the mixed gas; Step 3: Turn on the high-pressure gas cylinder switch. The tracer gas flows from the high-pressure gas cylinder outlet through the first straight pipe into the T-joint. The tracer gas then flows through the second straight pipe into the high-pressure side inlet of the pressure reducing valve. During this process, the check valve prevents gas backflow. Step 4: Use the rotary head to adjust the tracer gas pressure to about 0.5 MPa. The decompressed gas passes through the first elbow, the second elbow, the gas regulating valve assembly, and the flow meter in sequence from the low-pressure side outlet of the pressure reducing valve; Step 5: The flow meter feeds the measured flow value data back to the gas regulating valve assembly and displays it on the LCD touch screen; Step 6: The gas regulating valve assembly adjusts the tracer gas flow rate to the preset value based on the feedback flow value. The LCD touch screen displays the flow rate changes in real time and sets the maximum sulfur hexafluoride injection flow rate limit to 10L / min. Step 7: The air is collected and pressurized by a micro pneumatic pump and enters the confluence component; Step 8: The tracer gas enters the confluence assembly through the fourth elbow and is fully mixed with the air; Step 9: The built-in sulfur hexafluoride concentration infrared sensor feeds back the detected concentration value to the built-in controller and LCD touch screen of the confluence component to control the opening of the sulfur hexafluoride regulating valve until the mixed gas concentration reaches the preset value; Step 10: When the mixed gas flow rate and concentration are both stably output and reach the preset value, the nozzle of the spray gun is extended to an appropriate length and placed close to the area to be inspected of the nuclear condenser to release the mixed tracer gas; Step 11: Determine the leakage situation based on the measurement signal of the leak detector arranged at the outlet of the nuclear condenser vacuum system; Step 12: Wait for the leak detector signal to return to the background signal, retract the nozzle of the spray gun, and carry the release device to the next area to be tested until all areas to be tested are tested.

2. The detection method based on the nuclear condenser air leakage tracer gas release device according to claim 1 is characterized in that: The device also includes a display unit for displaying tracer gas flow rate and concentration information.

3. The detection method based on the nuclear condenser air leakage tracer gas release device according to claim 1 is characterized in that: The device further includes a power supply unit for supplying power to the gas decompression unit, the gas regulating unit, and the gas mixing unit.

4. The detection method based on the nuclear condenser air leakage tracer gas release device according to claim 1 is characterized in that: The device also includes a gas check unit for preventing the high-pressure gas that is filled into the device from the outside and merged with the tracer gas from flowing back or leaking. The gas check unit, the gas decompression unit and the gas storage unit are respectively connected to the three-way valve.

5. The detection method based on the nuclear condenser air leakage tracer gas release device according to claim 1 is characterized in that: The gas decompression unit includes a pressure reducing valve, a pressure gauge and a rotating head. The pressure gauge is installed on and outside the shell and is communicated with the pressure reducing valve. The rotating head for adjusting the outlet pressure of the pressure reducing valve is installed on the pressure reducing valve.

6. The detection method based on the nuclear condenser air leakage tracer gas release device according to claim 1 is characterized in that: The gas regulating unit includes a gas flow meter and a gas regulating valve assembly. The gas regulating valve assembly is fixed in the shell, one end of which is connected to the gas decompression unit through a first elbow, and the other end is connected to the flow meter through a second elbow.

7. The detection method based on the nuclear condenser air leakage tracer gas release device according to claim 1 is characterized in that: The housing includes a first housing and a second housing.

8. The detection method based on the nuclear condenser air leakage tracer gas release device according to claim 1 is characterized in that: The device also includes a spray gun nozzle, a spray gun nozzle sleeve, and a spray gun nozzle bracket arranged on the shell. The spray gun nozzle bracket is installed in the shell. One end of the spray gun nozzle is connected to the gas mixing unit through the spray gun nozzle sleeve, and the end is passed through the spray gun nozzle sleeve and the spray gun nozzle bracket. The other end of the spray gun nozzle extends out of the shell.

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