A hydrogen explosion prevention device after the failure of a sealing tile of a power generator of a thermal power plant

Abstract

A hydrogen explosion prevention device for generator sealing tile failure in thermal power plants includes a hydrogen concentration detection device, a channel nozzle, a cartridge nitrogen cylinder, a solenoid valve, and connecting pipelines. The hydrogen concentration detection device is installed on the outer end caps of the generator's steam and excitation ends. The channel nozzle is a complete ring of stainless steel channels surrounding the generator rotor, fixedly mounted to the end faces of the oil baffles at the generator's steam and excitation ends by brackets, with the nozzle orifice facing the gap between the oil baffle and the rotor. The solenoid valve is located on the nitrogen pipeline connecting to the gas outlet of the cartridge nitrogen cylinder. The connecting pipeline is a welded stainless steel pipe connecting the nitrogen pipeline downstream of the solenoid valve to the channel nozzles at both the steam and excitation ends of the generator. The hydrogen concentration detection device is electrically connected to the solenoid valve, achieving the purpose of reducing the hydrogen concentration in the hazardous area and buying time for emergency response by operating personnel.

Description

Technical Field

[0001] This invention relates to a hydrogen explosion prevention device for generator sealing tiles in thermal power plants after failure, belonging to the technical field of generator sealing tiles. Background Technology

[0002] During generator operation, leaked hydrogen gas will seep through the gap between the bearing and the shaft into the bearing end cover, the oil baffle inside the generator, and the outer end cover chamber. Some of the hydrogen gas will be carried into the oil tank end baffle and the exhaust fan installed on the top to the outside of the roof due to the negative pressure of the oil returning from the bearing to the main oil tank. The remaining hydrogen gas will escape in large quantities into the turbine hall through the gap between the rear oil baffle of the bearing housing and the generator end cover. The hydrogen gas that leaks outside the generator will accumulate near the generator grounding carbon brush and the exciter compartment. Upon encountering mechanical impact or open flame, it will directly cause a hydrogen explosion, thus causing a catastrophic accident. Summary of the Invention

[0003] To address the aforementioned problems in existing technologies, this invention provides a hydrogen explosion prevention device for generator sealing tiles in thermal power plants after failure, achieving the goal of reducing hydrogen concentration in hazardous areas and buying time for emergency response by operating personnel.

[0004] The technical solution of the present invention is as follows: A hydrogen explosion prevention device for a thermal power plant generator after sealing tile failure includes a hydrogen concentration detection device, a channel nozzle, a cartridge nitrogen cylinder, a solenoid valve, and connecting pipelines. The hydrogen concentration detection device is installed on the outer end caps of the generator's steam and excitation ends. The channel nozzle is a complete ring of stainless steel channels surrounding the generator rotor, fixedly mounted to the end faces of the oil baffles at the generator's steam and excitation ends by a bracket, with the nozzle orifice facing the gap between the oil baffle and the rotor. The solenoid valve is located on the nitrogen pipeline connecting to the gas outlet of the cartridge nitrogen cylinder. The connecting pipeline is a welded stainless steel pipe connecting the nitrogen pipeline downstream of the solenoid valve to the channel nozzles at both the steam and excitation ends of the generator. The hydrogen concentration detection device is electrically connected to the solenoid valve.

[0005] It also includes an annular isolation airbag and a catalytic elimination unit; the annular isolation airbag is fixedly installed on the generator outer end cover outside the channel nozzle; the cavity of the annular isolation airbag is connected to the outlet of the catalytic elimination unit through an inflation pipe, and the inflation pipe is equipped with a burst valve controlled by the signal of the hydrogen concentration detection device.

[0006] The catalytic elimination unit includes a reaction chamber filled with a hydrogen catalytic oxidation catalyst. The inlet of the reaction chamber is connected to the atmosphere through an intake pipe with a one-way valve, and its outlet is connected to the expansion pipe.

[0007] The catalytic elimination unit further includes a cooling system for controlling the temperature of the reaction chamber. The cooling system includes a cooling jacket fitted outside the reaction chamber, the cooling jacket having a cooling medium inlet and a cooling medium outlet. The cooling medium inlet is connected to the power plant's closed-loop cooling water system via a pipeline, and a regulating valve controlled by a temperature sensor is installed on the connecting pipeline. The temperature sensor is located on the cooling jacket. The cooling medium outlet returns to the closed-loop cooling water return system via a pipeline.

[0008] It also includes a circulating fan, the outlet of which is connected to the air intake pipe of the reaction chamber, and its inlet is connected to the atmosphere.

[0009] The annular isolation airbag has at least one exhaust micro-hole on its body, and the exhaust micro-hole is connected to the inlet of the exhaust branch pipe through an exhaust manifold; the outlet of the exhaust branch pipe is connected to the negative pressure pipeline of the generator's air-side sealing oil exhaust fan.

[0010] The annular isolation airbag has an elastic sealing lip on its inner ring edge, and its outer ring is sealed and fixedly installed on the generator outer end cover outside the channel nozzle by the fixing ring. The elastic sealing lip includes an annular base and multiple annular flexible sealing bodies. The annular base is fixedly connected to the inner ring edge of the annular isolation airbag. The annular flexible sealing bodies are connected to the annular base and form multiple pressure driving chambers. The pressure driving chambers are connected to the cavity of the annular isolation airbag through air guiding micro-holes opened inside the annular base. Each annular flexible sealing body is provided with an inert gas purging hole, which is located near the root of the elastic sealing lip, and the outlet direction of the inert gas purging hole is inclined towards the inner side of the contact area between the elastic sealing lip and the generator rotor.

[0011] The annular isolation airbag has an annular internal partition coaxially arranged inside its cavity; the internal partition divides the cavity into an outer inert gas cavity and an inner mixed gas cavity; the inlet of the gas guiding micropore communicates with the inert gas cavity; the inlet of the exhaust micropore communicates with the mixed gas cavity; the internal partition has several connecting holes filled with a hydrogen selective permeation membrane; and the outlet of the inflation tube is located inside the inert gas cavity.

[0012] The reaction chamber has a water collection tank at the bottom, and a drainage pipe is connected to the bottom of the water collection tank. The end of the drainage pipe is connected to the power plant's low-pressure drainage system. A drain valve is installed on the drainage pipe.

[0013] The annular airbag is made of a high-temperature resistant composite material with a low coefficient of friction and self-lubrication.

[0014] The present invention has the following beneficial effects: This invention utilizes the coordinated operation of a hydrogen concentration detection device with a channel nozzle, a solenoid valve, and a nitrogen pipeline. When the hydrogen concentration exceeds the standard, the system can immediately trigger high-pressure nitrogen to backflush the leaking gap. This achieves the goal of pushing most of the leaked hydrogen back into the generator's internal chamber and reducing the hydrogen concentration in the dangerous area in the first instance, thus buying time for operators to handle emergencies.

[0015] This invention, by setting up a series structure of an annular isolation gasbag and a catalytic elimination unit, allows the annular isolation gasbag to rapidly inflate and form a physical barrier when nitrogen backflushing fails to completely stop the leakage. At the same time, the catalytic unit converts the captured hydrogen into water, thereby achieving the purpose of confining the leaked hydrogen within a controllable space and safely eliminating it, effectively preventing the diffusion and accumulation of hydrogen in the plant.

[0016] This invention achieves cooling of the heat of catalytic oxidation reaction by equipping the catalytic elimination unit with a cooling jacket and regulating valve controlled by a temperature sensor and connecting it to the power plant's closed-loop cooling water system. This maintains the catalyst bed temperature within a safe and efficient operating range, preventing catalyst failure due to overheating and ensuring the continuous reliability of the catalytic elimination process.

[0017] This invention achieves safe drainage of treated exhaust gas by connecting the exhaust branch pipe of the annular isolation airbag to the negative pressure pipeline of the generator's inherent air-side sealed oil exhaust fan. Utilizing the continuous and stable suction force of the existing exhaust fan, it provides reliable exhaust power for the entire emergency gas treatment circuit and directs potentially hydrogen-containing exhaust gas into a dedicated safe emission system, preventing the formation of new gas accumulation points within the device or plant.

[0018] This invention achieves functional separation of the gas inside the airbag by opening an inert gas purging hole on the elastic sealing lip of the annular isolation airbag and setting an internal partition with a hydrogen selective permeation membrane to separate the chambers. This ensures that the dynamic sealing contact area is always in an inert and safe atmosphere and improves the purity of gas processing. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the backflush mechanism of the channel nozzle of the present invention; Figure 2 This is a schematic diagram of the annular isolation airbag of the present invention; Figure 3 This is a half-sectional view of the catalytic elimination unit structure of the present invention; Figure 4 This is a connection diagram of the circulating induced draft fan, the catalytic elimination unit, and the air-side sealing oil exhaust fan of the present invention; Figure 5This is a cross-sectional view of the annular isolation airbag of the present invention; Figure 6 This is a vertical cross-sectional view of the annular isolation airbag of the present invention.

[0020] The reference numerals in the figure are as follows: 1. Hydrogen concentration detection device; 2. Channel nozzle; 3. Containerized nitrogen cylinder; 4. Solenoid valve; 5. Connecting pipeline; 6. Annular isolation gasbag; 7. Catalytic elimination unit; 8. Inflation pipeline; 9. Intake pipeline; 11. Air-side sealing oil exhaust fan; 12. Internal partition; 61. Fixing ring; 62. Elastic sealing lip; 63. Exhaust micropore; 64. Exhaust manifold; 65. Exhaust branch pipe; 71. Reaction chamber; 72. Water collection tank; 73. Cooling jacket; 74. Drainage pipeline; 101. Circulating exhaust fan; 121. Inert gas chamber; 122. Mixed gas chamber; 123. Connecting hole; 124. Hydrogen selective permeation membrane; 621. Annular base; 622. Annular flexible seal; 623. Pressure drive chamber; 624. Gas guide micropore; 625. Inert gas purging hole. Detailed Implementation

[0021] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0022] Please see Figures 1 to 6 The invention provides a technical solution: The hydrogen explosion prevention device for the failure of the sealing tile of the generator in the thermal power plant in this embodiment includes a nitrogen purging assembly. The nitrogen purging assembly includes a hydrogen concentration detection device 1 for real-time monitoring of hazardous gases, a channel nozzle 2, a containerized nitrogen cylinder 3, a solenoid valve 4 for controlling the gas supply, and a connecting pipeline 5 for conveying gas.

[0023] Among them, the hydrogen concentration detection device 1 is installed in pairs on the outer end cover of the steam end and excitation end of the generator. This position is the primary accumulation area for hydrogen to escape after the sealing tile fails. The device continuously monitors the hydrogen volume percentage in the chamber through a precision sensor and sets the 4% hydrogen explosion lower limit as the warning threshold to achieve early warning of leakage.

[0024] The channel nozzle 2 is made of corrosion-resistant stainless steel and is a complete annular channel surrounding the generator rotor. It is firmly installed on the end face of the oil baffles at both ends of the generator steam and excitation by a rigid bracket to ensure the stability of the unit under vibration during operation. The narrow nozzle of the channel nozzle 2 is always directly facing the tiny gap between the oil baffle sealing ring and the high-speed rotating rotor journal, which is the main path for hydrogen leakage.

[0025] The containerized nitrogen cylinder 3, serving as a high-pressure gas source, is typically located on the operating floor of the turbine hall. The solenoid valve 4 is installed on the main pipeline at the outlet of the containerized nitrogen cylinder 3. The connecting pipeline 5 is connected downstream of the solenoid valve 4 and splits into two branches extending to the generator steam end and excitation end, ultimately connecting to the inlet port of the corresponding channel nozzle 2.

[0026] When the hydrogen concentration exceeds the standard, the system immediately triggers the opening of the solenoid valve 4. High-pressure nitrogen is delivered to the channel nozzle 2 through the pipeline 5. The high-speed nitrogen gas that is uniformly sprayed from the annular gap forms a stable gas curtain at the leakage gap, effectively pushing the overflowing hydrogen back into the internal cavity of the generator end cover, thereby significantly reducing the hydrogen concentration that leaks into the external danger area.

[0027] This solution further includes an annular isolation airbag 6 and a catalytic elimination unit 7.

[0028] Among them, the annular isolation airbag 6 is firmly installed on the generator outer end cover outside the channel nozzle 2 through its fixing ring. When the generator is running normally, the airbag is in a contracted and folded state under normal pressure, and its inner edge maintains a safe gap with the high-speed rotating rotor journal, thereby ensuring zero interference to the generator operation.

[0029] The annular isolation airbag 6 has its cavity connected to the outlet of the catalytic elimination unit 7 via a pressure-resistant inflation pipe 8. A burst valve, directly triggered by an alarm signal from the hydrogen concentration detection device 1, is connected in series on this inflation pipe 8. When nitrogen backflushing through the channel nozzle 2 fails to completely stop the leak, the burst valve is detonated upon receiving the signal, providing a pathway for subsequent actions. The annular isolation airbag 6 itself is made of a high-temperature resistant, oil-resistant, and highly flexible composite coated fabric, ensuring reliable operation even in harsh environments.

[0030] The catalytic elimination unit 7 is the core of the safe elimination of hydrogen, and its main body contains a reaction chamber 71. The reaction chamber 71 contains a highly active hydrogen catalytic oxidation catalyst uniformly loaded onto a honeycomb ceramic or metal corrugated belt as a carrier. In practice, catalysts with palladium or platinum as the main active component can be selected. These catalysts are characterized by extremely high catalytic activity within an operating temperature range of approximately 300°C, enabling a flameless catalytic oxidation reaction between hydrogen and oxygen, producing water and heat as products. This reaction rate is extremely fast, sufficient to handle dynamic changes in hydrogen leakage. To ensure a safe and controllable reaction process, the reaction chamber 71 is typically designed with sufficient catalyst loading and gas flow channels to ensure that the gas flow rate that can be processed per unit time meets the design maximum leakage rate requirements, while its structure also facilitates heat dissipation.

[0031] The air inlet of the reaction chamber 71 is connected to the atmosphere through an air intake pipe 9 with a one-way valve, which is used to prevent backflow of reaction products or pipeline gas; its air outlet is connected to the above-mentioned expansion pipe 8 through a flange, through which the inert gas (mainly nitrogen and carbon dioxide) and high-temperature water vapor generated after the reaction will be output.

[0032] This solution also integrates a circulating induced draft fan 101. The outlet of this fan 101 is connected to the intake pipe 9 of the reaction chamber 71, while its inlet is directly connected to the ambient air environment through a filter. Upon receiving a leak alarm signal, the fan and the rupture valve start synchronously, actively drawing air from the environment to create a forced airflow. This airflow continuously provides the necessary oxygen for the reaction in the catalytic bed and also ensures that any trace amounts of escaping hydrogen are effectively entrained and carried into the processing flow, thereby establishing a negative pressure zone at the system inlet.

[0033] The catalytic elimination unit 7 also includes a cooling system for controlling the temperature of the reaction chamber 71.

[0034] Hydrogen catalytic oxidation is a strongly exothermic reaction. If not controlled, the internal temperature of the chamber may rise sharply. This can not only cause the catalyst to sinter and deactivate due to overheating, affecting the reliability of long-term use, but also pose a safety hazard due to local overheating.

[0035] Therefore, the cooling system includes a cooling jacket 73 fitted around the outside of the reaction chamber 71, forming an annular flow channel between the jacket and the outer wall of the reaction chamber 71. The cooling jacket 73 has a cooling medium inlet and a cooling medium outlet. The cooling medium inlet is connected to a branch pipe of the power plant's existing closed-loop cooling water system via a pipeline. This connection utilizes the power plant's stable and reliable inherent cold source, eliminating the need for a separate cooling device. On the connecting pipe, there is a regulating valve controlled by a temperature sensor. The probe of the temperature sensor is usually mounted on the outer wall of the cooling jacket 73 by welding or close fitting to sense the wall temperature change of the reaction chamber.

[0036] During most of the generator's normal operation and leak-free period, the catalytic elimination unit 7 requires no cooling. The regulating valve design enables fully automatic start-up, shutdown, and regulation, reducing unnecessary energy consumption and equipment wear.

[0037] The cooling medium outlet returns to the power plant's closed-loop cooling water return system through another pipeline, forming a complete external circulation cooling loop.

[0038] When the reaction occurs, the temperature sensor monitors the temperature in real time and feeds the signal back to the regulating valve. If the temperature exceeds the set value, the regulating valve opens more to introduce more cooling water to enhance heat dissipation; if the temperature is low, the opening is reduced to save plant power consumption and water resources.

[0039] The annular isolation airbag 6 has at least one exhaust microhole 63 on its body. The exhaust microhole 63 is connected to the inlet of the exhaust branch pipe 65 through an exhaust manifold 64. The outlet of the exhaust branch pipe 65 is connected to the negative pressure pipeline of the air-side sealing oil exhaust fan 11 of the generator.

[0040] The aperture of the exhaust micro-holes 63 is calculated to ensure smooth gas discharge while maintaining the basic shape and internal pressure required for the operation of the annular isolation airbag 6. All gas discharged from the exhaust micro-holes 63 is collected by the exhaust manifold 64 and then enters the exhaust branch pipe 65. The outlet of this exhaust branch pipe 65 is connected to the negative pressure line of the generator's existing air-side sealing oil exhaust fan 11. The air-side sealing oil exhaust fan is a standard configuration of the hydrogen-cooled generator's sealing oil system; it operates continuously, establishing and maintaining a stable negative pressure in the return oil line to extract oil fumes and any trace amounts of hydrogen that may have intruded from the sealing oil.

[0041] The inner ring edge of the annular isolation airbag 6 is provided with an elastic sealing lip 62, and its outer ring is sealed and fixedly installed on the outer end of the generator outside the channel nozzle 2 by a fixing ring 61.

[0042] The elastic sealing lip 62 is a component that ensures an effective dynamic seal between the airbag and the high-speed rotating rotor after inflation. Its structure is not a simple integral ring, but rather consists of an annular base 621 and multiple independent annular flexible sealing bodies 622. The annular base 621 is firmly connected to the inner edge of the annular isolation airbag 6, while each flexible sealing body 622, together with the annular base 621, forms an independent pressure driving chamber 623.

[0043] During normal generator operation, the annular isolation airbag 6 is in a contracted state, and the flexible sealing body 622 slightly retracts due to its own elasticity, maintaining a safe gap with the rotor surface to ensure no interference with the main unit's operation. When a leak occurs, the annular isolation airbag 6 receives gas through the inflation pipe 8. Part of the gas enters the cavity of the annular isolation airbag 6 to inflate it, while the other part enters each pressure drive chamber 623 through the gas guide micropores 624.

[0044] The pressure-driven chamber 623 causes the flexible seal 622 to undergo uniform and gentle radial inward deformation, ensuring its working surface closely adheres to and follows the microscopic vibrations of the rotor, forming a dynamic contact sealing ring surrounding the rotor. To ensure absolute safety in this contact area, each flexible seal 622 is machined with an inert gas purging hole 625. This hole is located near the root of the sealing lip, and its outlet is angled towards the inner side of the contact area between the elastic sealing lip 62 and the rotor (i.e., the side closer to the generator). When gas enters the annular isolation bladder 6 and flows through this area, a portion is continuously ejected from these inert gas purging holes 625, forming a flowing inert gas curtain on the inner side of the sealing contact surface.

[0045] This air curtain serves a triple purpose: first, it purges and displaces any hydrogen that might seep into the area through the oil baffle gap; second, it fills the microenvironment between the elastic sealing lip 62 and the rotor with inert gas, preventing hydrogen explosion conditions; and third, the airflow itself provides some cooling and lubrication. The flexible seal 622 itself is made of a low-friction, self-lubricating, high-temperature resistant composite material, generating very little heat when rubbing against the metal rotor, and its maximum operating temperature is far below the ignition point of hydrogen.

[0046] An annular isolation gasbag 6 has an annular internal partition 12 coaxially arranged within its cavity, dividing the entire cavity into two independent annular chambers: an outer inert gas chamber 121 and an inner mixed gas chamber 122. The outlet of the inflation conduit 8 is located directly within the inert gas chamber 121, thus the gas from the catalytic elimination unit 7 first fills this chamber. The inlet of the gas guiding micropore 624 is also connected to this chamber, ensuring that the gas driving the elastic sealing lip 62 and the gas ejected from the inert gas purge port 625 originates from the inert gas in the inert gas chamber. The inlet of the exhaust micropore 63 is located in the mixed gas chamber 122, which is used to collect and exhaust hydrogen. The two chambers are connected by several connecting holes 123 on the partition 12, but these holes are filled with a special hydrogen-selective permeation membrane 124 (e.g., a palladium alloy membrane or certain polymer membranes with molecular sieve effects).

[0047] Its working principle is based on the difference in the permeation rate of gas molecules. Its permeation rate through this special membrane is much greater than that of inert gas molecules such as nitrogen and carbon dioxide. Therefore, when a very small amount of hydrogen is mixed into the inert gas chamber 121 for various reasons, the hydrogen will preferentially permeate through the permeation membrane 124 into the mixed gas chamber 122 under the drive of the partial pressure difference; while the main components of the inert gas are effectively blocked in the inert gas chamber 121.

[0048] The inert gas remains in the original cavity for sealing and purging, while the hydrogen is screened and enriched in the mixed gas cavity 122. Finally, the hydrogen-enriched mixed gas, under the negative pressure created by the exhaust fan 11, is continuously drawn away through the exhaust micro-hole 63 and discharged into the safety system. The inert gas is injected into the inert gas cavity 121 through the expansion pipe 8, one path driving the seal through the guide micro-hole 624, and the other path forming a protective gas curtain through the purging hole 625; the hydrogen is guided by the permeation membrane 124 to the mixed gas cavity 122 and finally discharged through the exhaust system.

[0049] The bottom of the reaction chamber 71 is provided with a water collection tank 72, and the bottom of the water collection tank 72 is connected to a drain pipe 74; the end of the drain pipe 74 is connected to the low-pressure drainage system of the power plant; a drain valve is provided on the drain pipe 74.

[0050] The embodiments described above are merely illustrative of specific implementations of the present invention, and while the descriptions are detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A hydrogen explosion prevention device for generator sealing tiles in thermal power plants after failure, characterized in that: The system includes a nitrogen purging assembly, an annular isolation gasbag (6), and a catalytic elimination unit (7). The nitrogen purging assembly forms a gas curtain with nitrogen to prevent hydrogen leakage. One end of the catalytic elimination unit (7) is connected to the atmosphere, and the other end is connected to the annular isolation gasbag (6). The inner ring edge of the annular isolation gasbag (6) is provided with an elastic sealing lip (62), and its outer ring is sealed and fixedly installed on the generator outer end cover outside the channel nozzle (2) by the fixing ring (61). An annular internal partition (12) is coaxially arranged inside the cavity of the annular isolation gasbag (6). (12) has several connecting holes (123) and the connecting holes (123) are filled with hydrogen selective permeation membranes (124); the internal partition (12) divides the cavity into an outer inert gas cavity (121) and an inner mixed gas cavity (122); the elastic sealing lip (62) is connected to the inert gas cavity (121) and the elastic sealing lip (62) is provided with an inert gas purging hole (625), and the outlet direction of the inert gas purging hole (625) is inclined to the inner side of the contact area between the elastic sealing lip (62) and the generator rotor.

2. The hydrogen explosion prevention device for the failure of the sealing tile of a thermal power plant generator as described in claim 1, characterized in that: The annular isolation airbag (6) has at least one exhaust microhole (63) on its body. The exhaust microhole (63) is connected to the inlet of the exhaust branch pipe (65) through an exhaust manifold (64). The outlet of the exhaust branch pipe (65) is connected to the negative pressure pipeline of the air-side sealing oil exhaust fan (11) of the generator.

3. The hydrogen explosion prevention device for the failure of the sealing tile of a thermal power plant generator as described in claim 2, characterized in that: The elastic sealing lip (62) includes an annular base (621) and multiple annular flexible sealing bodies (622). The annular base (621) is fixedly connected to the inner ring edge of the annular isolation airbag (6). The annular flexible sealing bodies (622) are connected to the annular base (621) and form multiple pressure driving chambers (623). The pressure driving chambers (623) are connected to the cavity of the annular isolation airbag (6) through air guiding micropores (624) opened inside the annular base (621). An inert gas purging hole (625) is provided near the root of the elastic sealing lip (62).

4. The hydrogen explosion prevention device for the failure of the sealing tile of a thermal power plant generator as described in claim 3, characterized in that: The inlet of the gas guiding micropore (624) is connected to the inert gas chamber (121); the inlet of the exhaust micropore (63) is connected to the mixed gas chamber (122); the cavity of the annular isolation bladder (6) is connected to the outlet of the catalytic elimination unit (7) through an expansion pipe (8), and the expansion pipe (8) is equipped with a burst valve controlled by the signal of the hydrogen concentration detection device (1), and the outlet of the expansion pipe (8) is located in the inert gas chamber (121).

5. The hydrogen explosion prevention device for the failure of the sealing tile of a thermal power plant generator as described in claim 4, characterized in that: The catalytic elimination unit (7) includes a reaction chamber (71) filled with a hydrogen catalytic oxidation catalyst. The inlet of the reaction chamber (71) is connected to the atmosphere through a suction pipe (9) with a one-way valve, and its outlet is connected to an annular isolation airbag (6).

6. The hydrogen explosion prevention device for the failure of the sealing tile of a thermal power plant generator as described in claim 5, characterized in that: The catalytic elimination unit (7) further includes a cooling system for controlling the temperature of the reaction chamber (71); the cooling system includes a cooling jacket (73) sleeved outside the reaction chamber (71), the cooling jacket (73) is provided with a cooling medium inlet and a cooling medium outlet; the cooling medium inlet is connected to the power plant's closed cooling water system through a pipeline, and a regulating valve controlled by a temperature sensor is provided on the connecting pipeline, the temperature sensor being installed on the cooling jacket (73); the cooling medium outlet returns to the closed cooling water return system through a pipeline.

7. The hydrogen explosion prevention device for the failure of the sealing tile of a thermal power plant generator as described in claim 6, characterized in that: It also includes a circulating fan (101), the outlet of which is connected to the air intake pipe (9) of the reaction chamber (71), and its inlet is connected to the atmosphere.

8. The hydrogen explosion prevention device for the failure of the sealing tile of a thermal power plant generator as described in claim 7, characterized in that: The nitrogen purging assembly includes a hydrogen concentration detection device (1), a channel nozzle (2), and a containerized nitrogen cylinder (3); the hydrogen concentration detection device (1) is installed on the outer end cover of the steam end and excitation end of the generator; the channel nozzle (2) is fixedly installed on the end face of the oil baffle at the steam end and excitation end of the generator by a bracket, and the nozzle of the channel nozzle (2) is directly facing the gap between the oil baffle and the rotor; the containerized nitrogen cylinder (3) is connected to the channel nozzle (2).

9. The hydrogen explosion prevention device for the failure of the sealing tile of a thermal power plant generator as described in claim 8, characterized in that: The bottom of the reaction chamber (71) is provided with a water collection tank (72), and the bottom of the water collection tank (72) is connected to a drainage pipe (74); the end of the drainage pipe (74) is connected to the low-pressure drainage system of the power plant; a drain valve is provided on the drainage pipe (74).

10. The hydrogen explosion prevention device for the failure of the sealing tile of a thermal power plant generator as described in claim 9, characterized in that: The annular isolation airbag (6) is made of a high-temperature resistant composite material with a low coefficient of friction and self-lubrication.

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