Helium pollution treatment device for helium leak detection of nuclear steam generator and use method of helium pollution treatment device

Abstract

The invention discloses a helium pollution treatment device for helium leak detection of a nuclear steam generator and a use method of the helium pollution treatment device. The treatment device comprises a purging mechanism, a suction mechanism, a detection mechanism, a first temporary plugging mechanism and a second temporary plugging mechanism. According to the helium leakage detection helium pollution treatment device for the nuclear steam generator, through the arrangement of the purging mechanism, the suction mechanism and the detection mechanism, the purpose of rapidly removing helium pollution in a primary side water chamber of an evaporator can be achieved through flow-controllable purging and suction-speed-controllable suction and through real-time monitoring of helium environment background signals in primary side water of the evaporator. A first temporary plugging mechanism and a second temporary plugging mechanism are arranged, a helium environment background signal in the primary side water chamber of the evaporator is monitored in real time, and the purpose of preventing the damaged heat transfer pipe from continuously leaking helium from the secondary side to the primary side of the evaporator to pollute the helium environment background in the primary side water chamber of the evaporator is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of nondestructive testing and leakage detection, and in particular to a helium leak detection and helium contamination treatment device for a nuclear steam generator and a use method thereof. Background Art

[0002] Steam generators are critical equipment in nuclear power plants, serving as a key component for heat exchange between the primary and secondary circuits. Regulations require helium leak testing of steam generator heat transfer tubes every ten years of operation or when other indicators are met. If helium contamination occurs, it must be promptly addressed to prevent it from affecting normal inspection signal detection. Helium contamination during evaporator helium leak testing is complex and variable, and in-service nuclear steam generators are highly radioactive, preventing prolonged close human contact. Therefore, different helium contamination treatment technologies are employed for different helium contamination conditions.

[0003] The existing technical solutions for treating helium gas pollution from evaporator helium leak detection are all kept secret abroad, and there is a lack of corresponding technical means in China to carry out relevant technical treatment. In order to further improve the post-treatment capabilities of evaporator helium leak detection technology, an effective technical means is urgently needed to treat helium gas pollution from evaporator helium leak detection. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a helium leak detection and helium contamination treatment device for a nuclear steam generator and a method for using the same.

[0005] The technical solution adopted by the present invention to solve the technical problem is to construct a helium leak detection and helium contamination treatment device for a nuclear steam generator, wherein the nuclear steam generator includes a heat transfer tube bundle and an evaporator primary side water chamber, the heat transfer tube bundle includes heat transfer tubes to be blocked, the heat transfer tubes to be blocked have hot end pipe openings and cold end pipe openings, and the evaporator primary side water chamber has a cold end manhole and a hot end manhole. The treatment device includes a purge mechanism, a suction mechanism, a detection mechanism, a first temporary blocking mechanism, and a second temporary blocking mechanism.

[0006] The purge mechanism is connected to the cold end manhole and is used to purge the interior of the nuclear steam generator;

[0007] The suction mechanism is connected to the hot end manhole and is used to suck the gas inside the nuclear steam generator;

[0008] The detection mechanism is connected to the hot end of the primary side water chamber of the evaporator and is used to detect the helium concentration at the hot end of the primary side water chamber of the evaporator;

[0009] The first temporary blocking mechanism is connected to the hot end pipe opening and is used to block the hot end pipe opening;

[0010] The second temporary blocking mechanism is connected to the cold end pipe opening and is used to block the cold end pipe opening.

[0011] In some embodiments, the purge mechanism includes an air compressor, an air diffuser, a purge pipeline, a flow meter, and a purge control valve;

[0012] The air diffuser is installed on the cold end manhole, the two ends of the purge pipeline are respectively connected to the air compressor and the air diffuser, and the flow meter and the purge control valve are arranged on the purge pipeline.

[0013] In some embodiments, the suction mechanism includes a suction device and an exhaust pipe, and both ends of the exhaust pipe are respectively connected to the hot end manhole and the suction device.

[0014] In some embodiments, the detection mechanism includes a sampling detection device and a first mass spectrometer leak detector. The sampling detection device is installed at the hot end tube plate inside the primary side water chamber of the evaporator, and the first mass spectrometer leak detector is connected to the sampling detection device.

[0015] In some embodiments, the first temporary blocking mechanism includes a first temporary blocking tool, an air extraction pipe, a flow controller, an air extraction pump, a suction gun, and a second mass spectrometer leak detector;

[0016] The first temporary plugging tool comprises a first plugging tool body, a first pneumatic claw connected to the first plugging tool body and used to plug the hot end pipe opening, a first sealing ring connected to the first plugging tool body and used to seal and press against the hot end pipe opening, a first eccentricity correction device connected to the first plugging tool body and used to align the first plugging tool body and the hot end pipe opening, and a first air tee connected to the hollow portion of the first plugging tool body;

[0017] The two ends of the air extraction pipe are respectively connected to the first air circuit tee and the air extraction pump, and the flow controller is arranged on the air extraction pipe;

[0018] Two ends of the suction gun are respectively connected to the first gas circuit tee and the second mass spectrometer leak detector.

[0019] In some embodiments, the first eccentricity correction device includes a plurality of elastic members and a connecting plate, the plurality of elastic members are connected to the bottom of the first blocking tool body, and the connecting plate is connected to the bottom of the plurality of elastic members.

[0020] In some embodiments, the second temporary blocking mechanism includes a second temporary blocking tool, a pressure-inducing pipe, a pressure gauge, and a pressure-stabilizing pipe;

[0021] The second temporary plugging tool includes a second plugging tool body, a second pneumatic claw connected to the second plugging tool body and used to plug the cold end pipe opening, a second sealing ring connected to the second plugging tool body and used to seal and press on the hot end pipe opening, a second eccentricity correction device connected to the second plugging tool body and used to achieve centering of the second plugging tool body and the cold end pipe opening, and a second air tee connected to the hollow portion of the second plugging tool body;

[0022] The two ends of the pressure-inducing pipe are respectively connected to the second gas circuit tee and the pressure gauge;

[0023] The voltage-stabilizing tube is connected to the second gas circuit tee, and one end of the voltage-stabilizing tube away from the second gas circuit tee is connected to the atmosphere.

[0024] In some embodiments, the processing device further includes a crawling robot, which is used to move components installed in the primary side water chamber of the evaporator.

[0025] In this embodiment, a method for using a nuclear steam generator helium leak detection helium contamination treatment device is also constructed, which is based on the nuclear steam generator helium leak detection helium contamination treatment device and includes the steps of:

[0026] S1. Detecting the nuclear steam generator using a total helium content monitor. If an abnormal signal is detected by the total helium content monitor, connecting a purge mechanism, a suction mechanism, and a detection mechanism to the nuclear steam generator;

[0027] S2. Start the air compressor and ensure that the air path is unobstructed to remove the contaminated helium at the cold end of the primary water chamber of the evaporator and the contaminated helium inside the heat transfer tube bundle;

[0028] S3, starting the suction device to extract the gas from the hot end of the primary side water chamber of the evaporator to remove the helium contamination at the hot end of the primary side water chamber of the evaporator;

[0029] S4. Use a first mass spectrometer leak detector to detect the helium content in the hot end of the primary water chamber of the evaporator. If the helium content is lower than a preset value, use the evaporator helium leak detection equipment to identify the leaking heat transfer tube to determine the heat transfer tube that needs to be plugged. Then, temporarily remove the purge mechanism, the suction mechanism, and the detection mechanism.

[0030] S5. Connect the first temporary blocking mechanism and the second temporary blocking mechanism to the heat transfer pipe to be blocked, and start the flow controller and the vacuum pump to extract the gas in the heat transfer pipe to be blocked, so as to remove the contaminated helium gas inside the heat transfer pipe.

[0031] S6. Simultaneously start the second mass spectrometer leak detector and the pressure gauge to detect the helium content inside the heat transfer tube to be plugged using the second mass spectrometer leak detector and detect the vacuum pressure change inside the heat transfer tube to be plugged using the pressure gauge;

[0032] S7. Reconnect and start the purge mechanism, the suction mechanism, and the detection mechanism. After the leakage detection signal acquisition of the overall helium content monitor is completed normally, remove the purge mechanism, the suction mechanism, the detection mechanism, the first temporary blocking mechanism, and the second temporary blocking mechanism.

[0033] In some embodiments, in step S1 , the types of abnormal signals occurring in the overall helium content monitor include: group instantaneous peak signals, violent fluctuation signals, and signals that rise slowly and cannot fall.

[0034] The implementation of the present invention has the following beneficial effects: The nuclear steam generator helium leak detection and helium contamination treatment device, by providing a purge mechanism, a suction mechanism, and a detection mechanism, can rapidly remove helium contamination from the evaporator's primary water chamber through controlled-flow purge and controlled-speed suction, while also monitoring the helium environmental background signal within the evaporator's primary water chamber in real time. Furthermore, a first temporary blocking mechanism 5 and a second temporary blocking mechanism are provided, and the helium environmental background signal within the evaporator's primary water chamber is monitored in real time, thereby preventing helium from leaking continuously from the evaporator's secondary side to the primary side through damaged heat transfer tubes, thereby contaminating the helium environmental background within the evaporator's primary water chamber 12. The nuclear steam generator helium leak detection and helium contamination treatment device and its use method can promptly and effectively treat helium contamination generated during the evaporator's helium leak detection process, thereby preventing it from impacting the normal operation of the evaporator's helium leak detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solution of the present invention, the present invention will be further described below with reference to the accompanying drawings and embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be considered as limiting the scope. A person of ordinary skill in the art can derive other relevant drawings based on these drawings without inventive effort. In the drawings:

[0036] Figure 1 is a schematic diagram of the application structure of the purge mechanism, the suction mechanism and the detection mechanism in some embodiments of the present invention;

[0037] Figure 2 is a schematic diagram of the application structure of the first temporary blocking mechanism and the second temporary blocking mechanism in some embodiments of the present invention;

[0038] Figure 3 It is a schematic structural diagram of a temporary blocking tool in some embodiments of the present invention. DETAILED DESCRIPTION

[0039] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific embodiments 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", "back", "up", "down", "left", "right", "longitudinal", "horizontal", "vertical", "horizontal", "top", "bottom", "inside", "outside", "head", "tail", etc. are based on the directions or positional relationships shown in the accompanying drawings and are constructed and operated in specific directions. They are only for the convenience of describing the technical solution and do not indicate that the devices or components referred to must have specific directions. Therefore, they should not be understood as limiting the present invention.

[0040] It should also be noted that, unless otherwise clearly specified and limited, terms such as "installed", "connected", "connected", "fixed", and "set" should be understood in a broad sense. For example, they can be fixedly connected, detachably connected, or integrated; they can be mechanically connected or electrically connected; they can be directly connected or indirectly connected through an intermediate medium, and they can be internal connections between two elements or interactions 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 one or more intermediate elements may be provided. The terms "first", "second", and "third" are only used to facilitate the description of the present technical solution and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second", and "third" can 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 invention can be understood according to the specific circumstances.

[0041] See also Figures 1 to 3, is a nuclear steam generator helium leak detection and helium contamination treatment device in some embodiments of the present invention, the nuclear steam generator includes a heat transfer tube bundle 11 and an evaporator primary side water chamber 12, the heat transfer tube bundle 11 includes a heat transfer tube 13 to be blocked, the heat transfer tube 13 to be blocked has a hot end pipe mouth 131 and a cold end pipe mouth 132, the evaporator primary side water chamber 12 has a cold end manhole 121 and a hot end manhole 122, the nuclear steam generator helium leak detection and helium contamination treatment device includes a purge mechanism 2, a suction mechanism 3, a detection mechanism 4, a first temporary blocking mechanism 5 and a second temporary blocking mechanism 6. The purge mechanism 2 is connected to the cold end manhole 121 and is used to purge the inside of the nuclear steam generator; the suction mechanism 3 is connected to the hot end manhole 122 and is used to suck the gas inside the nuclear steam generator; the detection mechanism 4 is connected to the hot end of the primary side water chamber 12 of the evaporator and is used to detect the helium concentration at the hot end of the primary side water chamber 12 of the evaporator; the first temporary blocking mechanism 5 is connected to the hot end pipe mouth 131 and is used to block the hot end pipe mouth 131; the second temporary blocking mechanism 6 is connected to the cold end pipe mouth 132 and is used to block the cold end pipe mouth 132.

[0042] like Figure 1 As shown, the purge mechanism 2 includes an air compressor 21, an air diffuser 22, a purge pipeline 23, a flow meter 24, and a purge control valve 25. The air diffuser 22 is installed on the cold end manhole 121. The two ends of the purge pipeline 23 are connected to the air compressor 21 and the air diffuser 22 respectively. The flow meter 24 and the purge control valve 25 are installed on the purge pipeline 23. The air compressor 21 is used to provide clean, oil-free compressed air. The total gas flow rate is usually required to be at least 2000Nm 3 / h, and the outlet of the air compressor 21 needs to be dehydrated and dried so that the dew point temperature of the outlet compressed air is at least 20°C lower than the ambient temperature. The air diffuser 22 is made of a material with a mechanical hardness lower than that of the steam generator equipment body, such as aluminum-magnesium alloy with high strength and low mechanical hardness, and the gas flow rate allowed is not less than 350Nm 3 / h. An air diffuser 22 is installed at the cold-end manhole 121 of the evaporator's primary water chamber 12. It purges clean, oil-free compressed air into the cold end of the evaporator's primary water chamber 12, ultimately discharging it out of the evaporator's primary water chamber 12 through the hot-end manhole 122. The contact surface between the air diffuser 22 and the cold-end manhole 121 is sealed with a rubber gasket. The rear end of the air diffuser 22 is connected to a purge line 23 via a quick-connect connector, and then to the air compressor 21. A flowmeter 24 monitors the intake air flow, and a purge control valve 25 is installed on the purge line 23 to control the intake air flow.

[0043] The suction mechanism 3 includes a suction device 31 and an exhaust pipe 32, and the two ends of the exhaust pipe 32 are respectively connected to the hot end manhole 122 and the suction device 31. Specifically, the suction device 31 is connected to one end of the exhaust pipe 32, and the other end of the exhaust pipe 32 is installed on the hot end manhole 122 of the primary side water chamber 12 of the evaporator. The hot end manhole 122 of the primary side water chamber 12 of the evaporator is reserved with an opening for pipeline passage to facilitate the subsequent routing of the pipelines of the first temporary blocking mechanism 5 and the second temporary blocking mechanism 6. The suction device 31 extracts the gas purged from the primary side water chamber 12 of the evaporator and ensures that external gas does not enter the interior of the primary side water chamber 12 of the evaporator through the reserved opening. This is because the internal gas entering the primary side water chamber 12 of the evaporator is extracted by a pumping speed higher than the purge flow rate, and the exhaust pumping speed is controlled by the suction device 31.

[0044] The detection mechanism 4 includes a sampling detection device 41 and a first mass spectrometer leak detector 42. The sampling detection device 41 is installed on the hot end tube sheet inside the primary water chamber 12 of the evaporator. The first mass spectrometer leak detector 42 is connected to the sampling detection device 41. The sampling detection device 41 can be a sniffer gun installed inside the primary water chamber 12 to sample and detect gas. The first mass spectrometer leak detector 42 can monitor the helium background environment inside the primary water chamber 12 in real time.

[0045] like Figure 2 and Figure 3 As shown, the first temporary blocking mechanism 5 includes a first temporary blocking fixture 51, an air extraction pipe 52, a flow controller 53, an air extraction pump 54, a suction gun 55, and a second mass spectrometer leak detector 56. The first temporary blocking fixture 51 includes a first blocking fixture body 511, a first pneumatic gripper 512 connected to the first blocking fixture body 511 and used to block the hot end pipe opening 131, a first sealing ring 513 connected to the first blocking fixture body 511 and used to seal and press against the hot end pipe opening 131, a first eccentricity correction device 514 connected to the first blocking fixture body 511 and used to achieve alignment between the first blocking fixture body 511 and the hot end pipe opening 131, and a first air channel tee 515 connected to the hollow portion of the first blocking fixture body 511. The two ends of the exhaust pipe 52 are respectively connected to the first air circuit tee 515 and the exhaust pump 54 , the flow controller 53 is set on the exhaust pipe 52 , and the two ends of the suction gun 55 are respectively connected to the first air circuit tee 515 and the second mass spectrometer leak detector 56 .

[0046] As can be understood, the first pneumatic gripper 512 can grip and press the hot end nozzle 131 of the heat transfer tube 13 to be sealed, with the first sealing ring 513 pressing the hot end nozzle 131 of the heat transfer tube 13 to be sealed to form a seal. Furthermore, the first eccentricity correction device 514 includes multiple elastic members 5141 and a connecting plate 5142. The multiple elastic members 5141 are connected to the bottom of the first sealing fixture body 511, and the connecting plate 5142 is connected to the bottom of the multiple elastic members 5141. The elastic member 5141 may be a spring. In this embodiment, there are four elastic members 5141, which are distributed at the four corners of the first blocking tool body 511. The connection between the elastic member 5141 and the connecting plate 5142 is a flexible connection, which can achieve deflection and torsion under a certain torque. In this way, when the first pneumatic gripper 512 and the hot end pipe mouth 131 of the heat transfer tube 13 to be blocked are not completely aligned, the deflection torque is used to press hard to achieve the eccentricity correction function between the first pneumatic gripper 512 and the hot end pipe mouth 131 of the heat transfer tube 13 to be blocked.

[0047] The first gas tee 515 is connected to the hollow structure of the first plugging tool body 511. One end of the first gas tee 515 is connected to a flow controller 53. An air pump 54 extracts the internal gas of the heat transfer tube 13 to be plugged through an air extraction pipe 52 and discharges it outside the evaporator's primary water chamber 12. This removes any helium leaking from the heat transfer tube 13 to be plugged, preventing it from continuously contaminating the helium background within the evaporator's primary water chamber 12. One end of the first gas tee 515 is connected to a suction gun 55. The tail end of the suction gun 55 is connected to a second mass spectrometer leak detector 56, which monitors the helium concentration in the heat transfer tube 13 in real time.

[0048] The second temporary sealing mechanism 6 includes a second temporary sealing fixture 61, a pressure-inducing tube 62, a pressure gauge 63, and a pressure-stabilizing tube 64. The second temporary sealing fixture 61 includes a second sealing fixture body 611, a second pneumatic gripper 612 connected to the second sealing fixture body 611 and used to seal the cold-end pipe opening 132, a second sealing ring 613 connected to the second sealing fixture body 611 and used to seal and press against the cold-end pipe opening 132, a second eccentricity correction device 614 connected to the second sealing fixture body 611 and used to align the second sealing fixture body 611 with the hot-end pipe opening 131, and a second gas tee 615 connected to the hollow portion of the second sealing fixture body 611. The pressure-inducing tube 62 is connected to the second gas tee 615 and the pressure gauge 63 at both ends, and the pressure-stabilizing tube 64 is connected to the second gas tee 615. The end of the pressure-stabilizing tube 64 away from the second gas tee 615 is exposed to the atmosphere.

[0049] Among them, the second temporary blocking fixture 61 has the same structure as the first temporary blocking fixture 51, which has been described in detail above and will not be repeated here. The first temporary blocking mechanism 5 and the second temporary blocking simultaneously block the two ends of the heat transfer tube 13 to be blocked, so that a relatively sealed environment is formed inside the heat transfer tube 13 to be blocked. In addition, the second gas circuit tee 615 is connected to the pressure gauge 63 through the pressure-inducing pipe 62, and the vacuum pressure inside the heat transfer tube 13 to be blocked is monitored in real time through the pressure gauge 63. One end of the second gas circuit tee 615 is connected to the pressure-stabilizing tube 64 directly to the atmosphere to stabilize the internal pressure of the heat transfer tube 13 to be blocked, so as to avoid the situation where the vacuum pump 54 evacuates air after the heat transfer tube 13 to be blocked is blocked, causing the vacuum inside the heat transfer tube 13 to be blocked to be too high, resulting in the first temporary blocking fixture 51 and the second temporary blocking fixture 61 being unable to be removed due to the vacuum negative pressure.

[0050] The processing device also includes a crawler robot 7, which is used to move components installed in the evaporator's primary water chamber 12. In this embodiment, the crawler robot 7 can move the sampling and testing equipment 41 to the hot end tube sheet of the evaporator's primary water chamber 12, and can also move the first temporary plugging tool 51 or the second temporary plugging tool 61 to the tube ends of the heat transfer tubes 13 to be plugged in the evaporator's primary water chamber 12.

[0051] The present invention achieves rapid and stable treatment of helium contamination inside the primary side water chamber 12 of the evaporator through the coordinated operation of the above-mentioned systems and components, and meets the purpose of normal evaporator helium leak detection signal acquisition after helium contamination occurs inside the primary side water chamber 12 of the evaporator.

[0052] In this embodiment, a method for using the nuclear steam generator helium leak detection helium contamination treatment device is also constructed, which is based on the above-mentioned nuclear steam generator helium leak detection helium contamination treatment device, and includes the steps of:

[0053] S1. Detecting the nuclear steam generator using the overall helium content monitor. If the overall helium content monitor shows an abnormal signal, connecting the purge mechanism 2, the suction mechanism 3, and the detection mechanism 4 to the nuclear steam generator;

[0054] S2. Start the air compressor 21 and ensure that the air path is unobstructed to remove the contaminated helium gas at the cold end of the primary side water chamber 12 of the evaporator and the contaminated helium gas inside the heat transfer tube bundle 11;

[0055] S3, starting the suction device to extract the gas from the hot end of the primary side water chamber 12 of the evaporator to remove the helium contamination at the hot end of the primary side water chamber 12 of the evaporator;

[0056] S4. Use the first mass spectrometer leak detector 42 to detect the helium content in the hot end of the primary water chamber 12 of the evaporator. If the helium content is lower than a preset value, use the evaporator helium leak detection equipment to identify the leaking heat transfer tubes to determine which heat transfer tubes need to be plugged. Then, temporarily remove the purge mechanism 2, the suction mechanism 3, and the detection mechanism 4.

[0057] S5. Connect the first temporary blocking mechanism 5 and the second temporary blocking mechanism 6 to the heat transfer tube 13 to be blocked, and start the flow controller 53 and the vacuum pump 54 to extract the gas in the heat transfer tube 13 to remove the contaminated helium gas inside the heat transfer tube 13.

[0058] S6. Simultaneously start the second mass spectrometer leak detector 56 and the pressure gauge 63. Use the second mass spectrometer leak detector 56 to detect the helium content inside the heat transfer tube 13 to be blocked, and use the pressure gauge 63 to detect the change in vacuum pressure inside the heat transfer tube 13 to be blocked.

[0059] S7. Reconnect and start the purge mechanism 2, the suction mechanism 3 and the detection mechanism 4. After the leakage detection signal acquisition of the overall helium content monitor is completed normally, remove the purge mechanism 2, the suction mechanism 3, the detection mechanism 4, the first temporary blocking mechanism 5 and the second temporary blocking mechanism 6.

[0060] Specifically, in step S1, the overall helium content monitor is used to detect helium leaks during routine steam generator operation. If the overall helium content monitor exhibits abnormal signal fluctuations, abnormal signal identification confirms helium contamination within the evaporator's primary water chamber 12, requiring treatment of the helium contamination. Abnormal helium content monitor signal types include: grouped instantaneous peak signals, violently fluctuating signals, and slowly rising signals that fail to decrease. Specifically, if the overall helium content monitor signal exceeds the peak value, exhibits violent fluctuations, or slowly rises and fails to decrease, it indicates helium contamination within the evaporator's primary water chamber 12.

[0061] In step S2, the air compressor 21 is started and the air path is confirmed to be unobstructed. Clean and oil-free compressed air is purged to the cold end of the primary water chamber 12 of the evaporator through the air diffuser 22, and continues to be purged to the hot end of the primary water chamber 12 of the evaporator through the heat transfer tube bundle 11, and finally discharged from the primary water chamber 12 of the evaporator through the hot end manhole 122. During the purging process, contaminated helium at the cold end of the primary water chamber 12 of the evaporator and inside the heat transfer tube bundle 11 is removed. The purge air intake flow of the air diffuser 22 is monitored by the flow meter 24, and the purge control valve 25 is operated to control the purge air intake flow of the air diffuser 22.

[0062] In step S3, the suction device is started to extract the gas at the hot end of the primary water chamber 12 of the evaporator, remove the helium contamination at the hot end of the primary water chamber 12 of the evaporator, and accelerate the gas flow in the heat transfer tube bundle 11, so as to achieve the purpose of removing the helium contamination in the primary water chamber 12 of the evaporator; at the same time, it is prevented that a high concentration of helium gas accumulates in the environment outside the hot end manhole 122, causing the helium gas in the environment outside the hot end manhole 122 to diffuse back into the interior of the primary water chamber 12 of the evaporator along the concentration gradient, and re-contaminate the helium environment background in the primary water chamber 12 of the evaporator.

[0063] In step S4, when the helium content detected by the first mass spectrometer leak detector 42 is lower than the preset value, it indicates that the helium environment background monitoring signal in the primary side water chamber 12 of the evaporator has temporarily returned to normal. Then, the evaporator helium leak detection equipment is used to quickly identify the leaking heat transfer tube, temporarily remove the purge mechanism 2, the suction mechanism 3 and the detection mechanism 4, and then take temporary blocking measures for the heat transfer tube 13 to be blocked.

[0064] In step S5, for the heat transfer tube that needs to be temporarily blocked, the first temporary blocking mechanism 5 and the second temporary blocking mechanism 6 are connected to the heat transfer tube 13 to be blocked, and the flow controller 53 and the vacuum pump 54 are started to extract the gas in the heat transfer tube 13 to be blocked, and the helium leaked in the heat transfer tube 13 to be blocked is extracted to the outside of the primary side water chamber 12 of the evaporator to avoid re-contamination of the helium environment background in the primary side water chamber 12 of the evaporator.

[0065] In step S6, the second mass spectrometer leak detector 56 and the pressure gauge 63 are started simultaneously. The gas inside the heat transfer tube 13 to be blocked is sampled by the sampling detection device 41 and transmitted to the second mass spectrometer leak detector 56. The second mass spectrometer leak detector 56 continuously monitors the helium environmental background signal inside the heat transfer tube 13 to be blocked. The vacuum pressure inside the heat transfer tube 13 to be blocked is transmitted to the pressure gauge 63 through the pressure lead pipe 62. The pressure gauge 63 continuously monitors the changes in the vacuum pressure inside the heat transfer tube 13 to be blocked.

[0066] In step S7, the purge mechanism 2, the suction mechanism 3 and the detection mechanism 4 are reconnected and started. After the leakage detection signal acquisition of the overall helium content monitor is completed normally, the purge mechanism 2, the suction mechanism 3, the detection mechanism 4, the first temporary blocking mechanism 5 and the second temporary blocking mechanism 6 are removed, and the helium leakage detection and helium contamination treatment work of the nuclear steam generator is completed.

[0067] The beneficial effects of the helium leak detection and helium contamination treatment device for a nuclear steam generator and its use method are as follows: by providing a purge mechanism 2, a suction mechanism 3, and a detection mechanism 4, the device can rapidly remove helium contamination within the evaporator's primary water chamber 12 through controlled-flow purge and controlled-speed suction, while also monitoring the helium environmental background signal within the evaporator's primary water chamber 12 in real time. Furthermore, a first temporary blocking mechanism 5 and a second temporary blocking mechanism 6 are provided, and real-time monitoring of the helium environmental background signal within the evaporator's primary water chamber 12 is performed to prevent helium from leaking continuously from the secondary side of the evaporator to the primary side of the damaged heat transfer tube, thereby contaminating the helium environmental background within the evaporator's primary water chamber 12. The device and its use method can promptly and effectively treat helium contamination generated during the evaporator's helium leak detection process, preventing it from affecting the normal operation of the evaporator's helium leak detection.

[0068] It can be understood that the above embodiments only express the preferred implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the patent scope of the present invention. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present invention, the above technical features can be freely combined, and several deformations and improvements can be made, all of which fall within the scope of protection of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should fall within the scope of coverage of the claims of the present invention.

Claims

1. A helium leak detection and helium contamination treatment device for a nuclear steam generator, wherein the nuclear steam generator comprises a heat transfer tube bundle (11) and an evaporator primary side water chamber (12), wherein the heat transfer tube bundle (11) comprises a heat transfer tube (13) to be blocked, wherein the heat transfer tube (13) to be blocked has a hot end tube opening (131) and a cold end tube opening (132), and wherein the evaporator primary side water chamber (12) has a cold end manhole (121) and a hot end manhole (122), wherein: The processing device comprises a purge mechanism (2), a suction mechanism (3), a detection mechanism (4), a first temporary blocking mechanism (5), and a second temporary blocking mechanism (6); The purging mechanism (2) is connected to the cold end manhole (121) and is used to purge the interior of the nuclear steam generator; The suction mechanism (3) is connected to the hot end manhole (122) and is used to suck the gas inside the nuclear steam generator; The detection mechanism (4) is connected to the hot end of the primary side water chamber (12) of the evaporator and is used to detect the helium concentration at the hot end of the primary side water chamber (12) of the evaporator; The first temporary blocking mechanism (5) is connected to the hot end pipe opening (131) and is used to block the hot end pipe opening (131); The second temporary blocking mechanism (6) is connected to the cold end pipe opening (132) and is used to block the cold end pipe opening (132).

2. The helium leak detection and helium contamination treatment device for a nuclear steam generator according to claim 1, characterized in that: The purge mechanism (2) includes an air compressor (21), an air diffuser (22), a purge pipeline (23), a flow meter (24) and a purge control valve (25); The air diffuser (22) is installed on the cold end manhole (121), the two ends of the purge pipeline (23) are respectively connected to the air compressor (21) and the air diffuser (22), and the flow meter (24) and the purge control valve (25) are arranged on the purge pipeline (23).

3. The helium leak detection and helium contamination treatment device for a nuclear steam generator according to claim 1, characterized in that: The suction mechanism (3) comprises a suction device (31) and an exhaust pipe (32), and both ends of the exhaust pipe (32) are respectively connected to the hot end manhole (122) and the suction device (31).

4. The helium leak detection and helium contamination treatment device for a nuclear steam generator according to claim 1, characterized in that: The detection mechanism (4) includes a sampling detection device (41) and a first mass spectrometer leak detector (42). The sampling detection device (41) is installed at the hot end tube plate inside the primary side water chamber (12) of the evaporator, and the first mass spectrometer leak detector (42) is connected to the sampling detection device (41).

5. The helium leak detection and helium contamination treatment device for a nuclear steam generator according to claim 1, characterized in that: The first temporary blocking mechanism (5) comprises a first temporary blocking tool (51), an air extraction pipe (52), a flow controller (53), an air extraction pump (54), a suction gun (55), and a second mass spectrometer leak detector (56); The first temporary blocking fixture (51) comprises a first blocking fixture body (511), a first pneumatic claw (512) connected to the first blocking fixture body (511) and used to block the hot end pipe opening (131), a first sealing ring (513) connected to the first blocking fixture body (511) and used to seal and press against the hot end pipe opening (131), a first eccentricity correction device (514) connected to the first blocking fixture body (511) and used to achieve alignment between the first blocking fixture body (511) and the hot end pipe opening (131), and a first air tee (515) connected to the hollow portion of the first blocking fixture body (511); The two ends of the air extraction pipe (52) are respectively connected to the first air circuit tee (515) and the air extraction pump (54), and the flow controller (53) is arranged on the air extraction pipe (52); The two ends of the suction gun (55) are respectively connected to the first gas circuit tee (515) and the second mass spectrometer leak detector (56).

6. The helium leak detection and helium contamination treatment device for a nuclear steam generator according to claim 5, characterized in that: The first eccentricity correction device (514) includes a plurality of elastic members (5141) and a connecting plate (5142), wherein the plurality of elastic members (5141) are connected to the bottom of the first blocking tool body (511), and the connecting plate (5142) is connected to the bottom of the plurality of elastic members (5141).

7. The helium leak detection and helium contamination treatment device for a nuclear steam generator according to claim 1, characterized in that: The second temporary blocking mechanism (6) comprises a second temporary blocking tool (61), a pressure-guiding tube (62), a pressure gauge (63), and a pressure-stabilizing tube (64); The second temporary blocking fixture (61) comprises a second blocking fixture body (611), a second pneumatic claw (612) connected to the second blocking fixture body (611) and used to block the cold end pipe opening (132), a second sealing ring (613) connected to the second blocking fixture body (611) and used to seal and press against the hot end pipe opening (131), a second eccentricity correction device (614) connected to the second blocking fixture body (611) and used to achieve alignment between the second blocking fixture body (611) and the cold end pipe opening (132), and a second air tee (615) connected to the hollow portion of the second blocking fixture body (611); The two ends of the pressure-inducing pipe (62) are respectively connected to the second gas circuit tee (615) and the pressure gauge (63); The voltage-stabilizing tube (64) is connected to the second gas circuit tee (615), and one end of the voltage-stabilizing tube (64) away from the second gas circuit tee (615) is connected to the atmosphere.

8. The helium leak detection and helium contamination treatment device for a nuclear steam generator according to claim 1, characterized in that: The processing device further comprises a crawling robot (7), and the crawling robot (7) is used to drive the components installed in the primary side water chamber (12) of the evaporator to move.

9. A method for using a helium leak detection and helium contamination treatment device for a nuclear steam generator, based on the helium leak detection and helium contamination treatment device for a nuclear steam generator according to any one of claims 1 to 8, characterized in that: Including steps; S1. Detecting the nuclear steam generator using a total helium content monitor. If the total helium content monitor shows an abnormal signal, connecting the purge mechanism (2), the suction mechanism (3) and the detection mechanism (4) to the nuclear steam generator; S2. Start the air compressor (21) and ensure that the air path is unobstructed to remove the contaminated helium gas at the cold end of the primary side water chamber (12) of the evaporator and the contaminated helium gas inside the heat transfer tube bundle (11); S3, starting the suction device to extract the gas from the hot end of the primary side water chamber (12) of the evaporator to remove the helium contamination at the hot end of the primary side water chamber (12) of the evaporator; S4. Using a first mass spectrometer leak detector (42), the helium content in the hot end of the primary side water chamber (12) of the evaporator is detected. If the helium content is lower than a preset value, the evaporator helium leak detection device is used to identify the leaking heat transfer tube to determine the heat transfer tube that needs to be blocked. Then, the purge mechanism (2), the suction mechanism (3), and the detection mechanism (4) are temporarily removed. S5, connecting the first temporary blocking mechanism (5) and the second temporary blocking mechanism (6) to the heat transfer tube (13) to be blocked, and starting the flow controller (53) and the air extraction pump (54) to extract the gas in the heat transfer tube (13) to be blocked, so as to remove the contaminated helium gas inside the heat transfer tube (13) to be blocked; S6. Simultaneously start the second mass spectrometer leak detector (56) and the pressure gauge (63), use the second mass spectrometer leak detector (56) to detect the helium content inside the heat transfer tube (13) to be blocked, and use the pressure gauge (63) to detect the change in vacuum pressure inside the heat transfer tube (13) to be blocked; S7, reconnecting and starting the purge mechanism (2), the suction mechanism (3) and the detection mechanism (4), and after the leakage detection signal acquisition of the overall helium content monitor is completed normally, dismantling the purge mechanism (2), the suction mechanism (3), the detection mechanism (4), the first temporary blocking mechanism (5) and the second temporary blocking mechanism (6).

10. The method for using the helium leak detection and helium contamination treatment device for a nuclear steam generator according to claim 9, characterized in that: In step S1 , the types of abnormal signals that appear in the overall helium content monitor include: group instantaneous peak signals, violent fluctuation signals, and signals that rise slowly and cannot fall.

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