A gas flammability analysis system in containment

Abstract

The invention discloses a system for analyzing the flammability of gas in a containment, comprising a sampling probe, a sampling valve, a water vapor sensor, a water vapor condensation device, a pressure sensor, a condensate collecting valve, a condensate tank, a measurement front valve, a first circulation vacuum pump, a vacuum valve, a vacuum pump, a first spiral tube inlet valve, a first spiral tube, a first spiral tube pressure sensor, a first spiral tube outlet valve, a second circulation vacuum pump and an oxygen analyzer; water vapor is collected by the water vapor condensation device, and the amount of water vapor is measured by the water vapor sensor; hydrogen is adsorbed by a palladium-based alloy coated on the inner wall surface of the first spiral tube, and the concentration of hydrogen can be determined by the pressure difference after the hydrogen is adsorbed, thereby reducing the concentration of hydrogen and the risk of combustion and explosion; the oxygen analyzer is used to analyze the concentration of oxygen, thereby more accurately judging whether the gas is flammable, thereby improving the safety and reliability of the system.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear safety analysis, and in particular to a system for analyzing the flammability of gases in a containment vessel. Background Art

[0002] After a severe nuclear power plant accident, the early reaction of zirconium with water and the subsequent irradiation-induced decomposition of water can lead to the generation of large amounts of non-condensable gases within the containment, particularly hydrogen. This gas can rapidly accumulate within the containment, creating the risk of combustion or explosion when mixed with other gases, posing a significant threat to the integrity of the containment. The control of hydrogen risk within the containment after a severe nuclear power plant accident has attracted widespread attention both domestically and internationally. Risk control and gas flammability analysis within the containment after a severe nuclear power plant accident are essential, requiring simultaneous measurement of water vapor, oxygen, and hydrogen concentrations.

[0003] Currently, domestic and international approaches to hydrogen risk control within containment vessels following severe nuclear power plant accidents typically rely solely on measuring the hydrogen concentration at a specific location within the containment. Gas flammability is determined by the combined effects of water vapor, oxygen, and hydrogen concentrations. Measuring hydrogen concentration alone cannot effectively and accurately determine gas flammability, leading to an inability to effectively and quickly implement safety measures and activate safety systems, potentially permanently damaging the integrity of the containment. Therefore, developing a system for analyzing the flammability of containment gases that can simultaneously measure water vapor, oxygen, and hydrogen concentrations is a pressing task. Summary of the Invention

[0004] In view of the defects existing in the prior art, the object of the present invention is to provide a gas flammability analysis system in a containment vessel that can simultaneously measure the water vapor concentration, oxygen concentration and hydrogen concentration.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] In order to solve the above technical problems, the present invention provides a system for analyzing the flammability of gas in a containment vessel, comprising a sampling probe, a sampling valve, a water vapor sensor, a water vapor condensation device, a pressure sensor, a condensate collecting valve, a condensate tank, a measurement front valve, a first circulation vacuum pump, a vacuum valve, a vacuum pump, a first spiral tube inlet valve, a first spiral tube, a first spiral tube pressure sensor, a first spiral tube outlet valve, a second circulation vacuum pump and an oxygen analyzer; a sampling probe, a sampling valve, a water vapor sensor, a water vapor condensation device, a measurement front valve, a first circulation vacuum pump, a first spiral tube inlet valve, a first spiral tube, a first spiral tube pressure sensor, a first spiral tube outlet valve, a second circulation vacuum pump and an oxygen analyzer; a sampling probe, a sampling valve, a water vapor sensor, a water vapor condensation device, a measurement front valve, a first circulation vacuum pump, a first spiral tube inlet valve, a first spiral tube The coil, the first spiral tube outlet valve, the second circulating vacuum pump and the oxygen analyzer are connected in sequence through pipelines; a water outlet hole is opened at the bottom of the water vapor condensation device, and the water outlet hole is connected with the condensed water collecting valve and the condensed water tank in sequence; a gas-liquid isolation plate is provided in the water vapor condensation device, and the gas-liquid isolation plate is located above the water outlet hole; the vacuum pump and the vacuum valve are connected with the water vapor condensation device in sequence; a pressure sensor is provided on the water vapor condensation device; the first spiral tube pressure sensor is provided on the first spiral tube; the inner wall surface of the first spiral tube is coated with a palladium-based alloy, and the outer wall surface of the first spiral tube is installed with an electric heating device.

[0007] Furthermore, the gas flammability analysis system in the containment also includes a gas recovery valve and a gas recovery pump, one end of the gas recovery valve is connected to the oxygen analyzer, the other end of the gas recovery valve is connected to one end of the gas recovery pump, and the other end of the gas recovery pump is used to connect to the containment.

[0008] Furthermore, the gas flammability analysis system in the containment also includes a second spiral tube inlet valve, a second spiral tube, a second spiral tube pressure sensor and a second spiral tube outlet valve. The second spiral tube inlet valve, the second spiral tube and the second spiral tube outlet valve are connected in sequence. The second spiral tube inlet valve is connected to the vacuum pump, the second spiral tube outlet valve is connected to the second circulating vacuum pump, and the second spiral tube pressure sensor is arranged on the second spiral tube; the inner wall surface of the second spiral tube is coated with a palladium-based alloy, and the outer wall surface of the second spiral tube is installed with another electric heating device.

[0009] Furthermore, the gas flammability analysis system in the containment also includes a first spiral tube purge front valve, a first spiral tube purge rear valve and a high-pressure inert gas tank. The high-pressure inert gas tank is connected to one end of the first spiral tube purge front valve, the other end of the first spiral tube purge front valve is connected to the pipeline between the first spiral tube inlet valve and the first spiral tube, one end of the first spiral tube purge rear valve is connected to the pipeline between the first spiral tube and the first spiral tube outlet valve, and the other end of the first spiral tube purge rear valve is connected to the pipeline between the gas recovery valve and the gas recovery pump.

[0010] Furthermore, the gas flammability analysis system in the containment also includes a second spiral tube purge front valve and a second spiral tube purge rear valve, one end of the second spiral tube purge front valve is connected to the high-pressure inert gas tank, the other end of the second spiral tube purge front valve is connected to the pipeline between the second spiral tube inlet valve and the second spiral tube, one end of the second spiral tube purge rear valve is connected to the pipeline between the second spiral tube and the second spiral tube outlet valve, and the other end of the second spiral tube purge rear valve is connected to the pipeline between the gas recovery valve and the gas recovery pump.

[0011] Furthermore, the gas flammability analysis system in the containment also includes a condensate backflush valve, one end of the condensate backflush valve is connected to the high-pressure inert gas tank, and the other end of the condensate backflush valve is connected to the pipeline between the condensate collection valve and the condensate tank.

[0012] Furthermore, the gas flammability analysis system in the containment vessel also includes a condensate discharge valve, one end of the condensate discharge valve is connected to the condensate tank, and the other end of the condensate discharge valve is connected to the containment vessel.

[0013] Furthermore, the gas flammability analysis system in the containment vessel also includes a condensate tank level gauge, which is connected to the condensate tank.

[0014] Furthermore, the electric heating device is an electric heating belt or a conductive heating film.

[0015] Furthermore, there are multiple sampling probes and sampling valves, and the multiple sampling probes and the multiple sampling valves are connected in a one-to-one correspondence, and the multiple sampling valves are all connected to the water vapor sensor.

[0016] The beneficial effects of the present invention are as follows: a gas flammability analysis system in a containment vessel provided by the present invention has the ability to simultaneously measure water vapor concentration, oxygen concentration and hydrogen concentration when in use, collects water vapor through a water vapor condensation device, and measures the amount of water vapor through a water vapor sensor; hydrogen is adsorbed by a palladium-based alloy coated on the inner wall surface of the first spiral tube, and the concentration of hydrogen can be determined by the pressure difference after the hydrogen is adsorbed, thereby reducing the concentration of hydrogen and the risk of combustion and explosion; and the use of an oxygen analyzer to analyze the oxygen concentration can more accurately determine whether the gas is flammable, thereby improving the safety and reliability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the structure of the containment gas flammability analysis system provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0018] The present invention will be further described in detail below with reference to the accompanying drawings and specific implementations.

[0019] Example 1

[0020] Combine Figure 1 As shown, a system for analyzing the flammability of gas in a containment vessel of the present embodiment includes a sampling probe 1, a sampling valve 2, a water vapor sensor 3, a water vapor condensation device 4, a pressure sensor 5, a condensed water collection valve 6, a condensed water tank 7, a pre-measurement valve 8, a first circulating vacuum pump 9, a vacuum valve 10, a vacuum pump 11, a first spiral tube inlet valve 12, a first spiral tube 13, a first spiral tube pressure sensor 14, a first spiral tube outlet valve 15, a second circulating vacuum pump 16 and an oxygen analyzer 17.

[0021] The sampling probe 1, sampling valve 2, water vapor sensor 3, water vapor condensation device 4, pre-measurement valve 8, first circulating vacuum pump 9, first spiral tube inlet valve 12, first spiral tube 13, first spiral tube outlet valve 15, second circulating vacuum pump 16, and oxygen analyzer 17 are sequentially connected via pipelines. It is worth noting that in this embodiment, there are four sampling probes 1 and four sampling valves 2, each of which is connected to a corresponding one-to-one relationship. All four sampling valves 2 are connected to the water vapor sensor 3. Of course, the number of sampling probes 1 and sampling valves 2 can be selected based on actual needs. Furthermore, a stainless steel bracket with slide rails is installed inside the containment vessel. The sampling probe 1 can be placed on this bracket and freely moved to different locations within the containment vessel. A gas filter membrane is installed inside the sampling probe 1 to filter aerosols and other larger impurities. The sampling pipeline between the containment vessel and the water vapor condensation device 4 is wrapped with a heating tape and thermal insulation to prevent condensation of water vapor in the gas inside the sampling pipeline.

[0022] A water outlet is provided at the bottom of the water vapor condensing device 4. In this embodiment, the diameter of the water outlet is 20 mm. The water outlet is connected to the condensed water collecting valve 6 and the condensed water tank 7 in sequence. A gas-liquid isolation plate is provided in the water vapor condensing device 4, and the gas-liquid isolation plate is located above the water outlet. A cooling sleeve is also provided on the outside of the water vapor condensing device 4. There is continuously circulating cooling water with a temperature of 5-10°C inside the cooling sleeve, which can cool the gas to 5-10°C, greatly reducing the saturation pressure of water vapor. The gas-liquid isolation plate provided inside the water vapor condensing device 4 can move up and down and freely expand and contract, which can realize the effective separation of gas and condensed water, improve the measurement accuracy of water vapor concentration, oxygen concentration and hydrogen concentration, and at the same time, reduce the gas temperature, thereby reducing the risk of combustion or explosion caused by the mixture of hydrogen and other gases, and improving the safety and reliability of the system.

[0023] The condensate tank 7 is made of stainless steel, has a volume of 50 mL, and has a liquid level scale inside. The containment gas flammability analysis system of this embodiment also includes a condensate tank level gauge 31 , which is connected to the condensate tank 7 .

[0024] The vacuum pump 11 and the vacuum valve 10 are sequentially connected to the water vapor condenser 4; the pressure sensor 5 is mounted on the water vapor condenser 4; and the first helical tube pressure sensor 14 is mounted on the first helical tube 13. The inner wall of the first helical tube 13 is coated with a palladium-based alloy, and an electric heating device is mounted on the outer wall of the first helical tube 13. In this embodiment, the electric heating device is an electric heating tape wrapped around the first helical tube 13. The electric heating tape is constructed of multiple resistance wires within glass fiber asbestos, and heats the outer wall of the first helical tube 13 by energizing it.

[0025] Furthermore, the gas flammability analysis system in the containment of this embodiment also includes a gas recovery valve 18 and a gas recovery pump 19. One end of the gas recovery valve 18 is connected to the oxygen analyzer 17, and the other end of the gas recovery valve 18 is connected to one end of the gas recovery pump 19. The other end of the gas recovery pump 19 is used to connect to the containment.

[0026] Furthermore, the gas flammability analysis system in the containment of this embodiment also includes a second spiral tube inlet valve 20, a second spiral tube 21, a second spiral tube pressure sensor 22 and a second spiral tube outlet valve 23. The second spiral tube inlet valve 20, the second spiral tube 21 and the second spiral tube outlet valve 23 are connected in sequence. The second spiral tube inlet valve 20 is connected to the vacuum pump 11, the second spiral tube outlet valve 23 is connected to the second circulating vacuum pump 16, and the second spiral tube pressure sensor 22 is arranged on the second spiral tube 21; the inner wall surface of the second spiral tube 21 is coated with a palladium-based alloy, and the outer wall surface of the second spiral tube 21 is installed with another electric heating device.

[0027] Furthermore, the containment gas flammability analysis system of this embodiment also includes a first spiral tube pre-purge valve 24, a first spiral tube post-purge valve 27, and a high-pressure inert gas tank 26. The high-pressure inert gas tank 26 is connected to one end of the first spiral tube pre-purge valve 24, the other end of the first spiral tube pre-purge valve 24 is connected to the pipeline between the first spiral tube inlet valve 12 and the first spiral tube 13, one end of the first spiral tube post-purge valve 27 is connected to the pipeline between the first spiral tube 13 and the first spiral tube outlet valve 15, and the other end of the first spiral tube post-purge valve 27 is connected to the pipeline between the gas recovery valve 18 and the gas recovery pump 19. The palladium-based alloy coated in the spiral tube is sponge-like or colloidal. The hydrogen concentration is measured based on the principle that the palladium-based alloy absorbs hydrogen. The hydrogen concentration can be obtained by calculating the pressure difference between the gas before and after entering the spiral tube. This also achieves the purpose of separating hydrogen from other gases, reducing the risk of combustion or explosion caused by the mixture of hydrogen and other gases, and improving the safety and reliability of the system. Two spiral tubes are also provided, one for hydrogen adsorption measurement and the other for hydrogen desorption purging, which can realize simultaneous and continuous switching operation of the two tubes, thereby improving the durability and availability of the system.

[0028] Furthermore, the containment gas flammability analysis system of this embodiment further includes a second spiral tube pre-purge valve 25 and a second spiral tube post-purge valve 28. One end of the second spiral tube pre-purge valve 25 is connected to the high-pressure inert gas tank 26, and the other end of the second spiral tube pre-purge valve 25 is connected to the pipeline between the second spiral tube inlet valve 20 and the second spiral tube 21. One end of the second spiral tube post-purge valve 28 is connected to the pipeline between the second spiral tube 21 and the second spiral tube outlet valve 23, and the other end of the second spiral tube post-purge valve 28 is connected to the pipeline between the gas recovery valve 18 and the gas recovery pump 19. It is worth noting that the first spiral tube 13 and the second spiral tube 21 of this embodiment have the same spiral direction.

[0029] Furthermore, the containment gas flammability analysis system of this embodiment also includes a condensate backflush valve 29, one end of the condensate backflush valve 29 is connected to the high-pressure inert gas tank 26, and the other end of the condensate backflush valve 29 is connected to the pipeline between the condensate collection valve 6 and the condensate tank 7.

[0030] Furthermore, the containment gas flammability analysis system of this embodiment further includes a condensate discharge valve 30 , one end of the condensate discharge valve 30 is connected to the condensate tank 7 , and the other end of the condensate discharge valve 30 is connected to the containment.

[0031] The specific method of using the containment gas flammability analysis system of this embodiment is as follows: First, the vacuum valve 10 and vacuum pump 11 are opened in sequence to evacuate the water vapor condenser 4. The second spiral tube purge front valve 25, the second spiral tube purge rear valve 28, and the gas recovery pump 19 are opened in sequence to evacuate the first spiral tube 13 and the second spiral tube 21. When the pressure sensor 5, the first spiral tube pressure sensor 14, and the second spiral tube pressure sensor 22 measure a value of 0 bar, the vacuum pump 11, vacuum valve 10, gas recovery pump 19, the second spiral tube purge front valve 25, and the second spiral tube purge rear valve 28 are closed in sequence. At this point, the water vapor condenser 4, the first spiral tube 13, and the second spiral tube 21 are in a vacuum state, and then the water vapor concentration, oxygen concentration, and hydrogen concentration in the gas are measured. The sampling valve 2 is opened, and the gas in the containment passes through the sampling probe 1, the sampling valve 2, and the water vapor sensor 3, and finally enters the water vapor condenser 4. When the pressure sensor 5 measures 1 bar, the sampling valve 2 is closed and the condensate collection valve 6 is opened. If the gas contains water vapor, it will condense. If the gas does not contain water vapor, no water vapor condenses, and the gas temperature drops to 5-10°C. The water vapor concentration can be determined from the value measured by the water vapor sensor 3. The condensate tank level gauge 31 measures the condensate level inside the condensate tank 7 in real time. The condensate will eventually enter the condensate tank 7. When the value measured by the condensate tank level gauge 31 stabilizes, the condensate collection valve 6 is closed.

[0032] The pre-measurement valve 8, first spiral tube inlet valve 12, and first circulating vacuum pump 9 are sequentially opened to transfer all the gas inside the water vapor condenser 4 to the interior of the first spiral tube 13. When the pressure sensor 5 measures 0 bar, the first circulating vacuum pump 9, pre-measurement valve 8, and first spiral tube inlet valve 12 are sequentially closed. Once the measurement value of the first spiral tube pressure sensor 14 stabilizes, the hydrogen concentration is calculated by calculating the difference in gas pressure before and after entering the spiral tube, whose inner wall is coated with a palladium-based alloy material.

[0033] When the measured value of the condensate tank level gauge 31 reaches the set upper limit, the condensate backflush valve 29 is opened, and the condensate inside the condensate tank 7 is sent back to the inside of the containment shell. When the measured value of the condensate tank level gauge 31 reaches the set lower limit, the condensate backflush valve 29 is closed. After the first spiral tube 13 adsorbs hydrogen for a certain period of time, the second spiral tube 21 adsorbs hydrogen in the same process. The heating film on the outer wall of the first spiral tube 13 is energized to heat the first spiral tube 13. The heating temperature range is from room temperature to 300°C, and the heating temperature can be adjusted automatically. The hydrogen adsorbed by the palladium-based alloy will desorb into the first spiral tube 13, causing the pressure inside the first spiral tube 13 to increase. When the measurement value of the first spiral tube pressure sensor 14 stabilizes, the first spiral tube purge front valve 24 and the first spiral tube purge rear valve 27 are opened in sequence. After a period of time, the first spiral tube purge front valve 24 is closed, and the desorbed hydrogen and inert gas are sent back to the containment through the gas recovery pump 19. When the measurement value of the first spiral tube pressure sensor 14 reaches 0 bar, the gas recovery pump 19 and the first spiral tube purge rear valve 27 are closed in sequence.

[0034] The first spiral tube outlet valve 15 and the second circulating vacuum pump 16 are opened sequentially, and all the gas inside the first spiral tube 13 is sent to the interior of the oxygen analyzer 17. When the value measured by the first spiral tube pressure sensor 14 reaches 0 bar, the second circulating vacuum pump 16 and the first spiral tube outlet valve 15 are closed sequentially, and the oxygen concentration can be obtained from the value measured by the oxygen analyzer 17. The gas recovery valve 18 and the gas recovery pump 19 are opened sequentially to return all the gas inside the oxygen analyzer 17 to the interior of the containment vessel, and the gas recovery pump 19 and the gas recovery valve 18 are closed sequentially.

[0035] Example 2

[0036] As another embodiment of the present invention, unlike the previous embodiment, the electric heating device installed on the outer wall surfaces of the first spiral tube 13 and the second spiral tube 21 in the containment gas flammability analysis system of this embodiment is a conductive heating film. The conductive heating film is structured as a selenium oxide conductive heating film. A plurality of evenly distributed resistance wires are arranged within the conductive heating film, and the outer wall surfaces of the first spiral tube 13 and the second spiral tube 21 are heated by electricity. The conductive heating film can make the first spiral tube 13 and the second spiral tube 21 in the containment gas flammability analysis system easier to arrange, making the containment gas flammability analysis system more compact.

[0037] A system for analyzing the flammability of gas in a containment vessel of the present invention is capable of simultaneously measuring the concentrations of water vapor, oxygen, and hydrogen when in use. Water vapor is collected by a water vapor condenser 4, and the amount of water vapor is measured by a water vapor sensor 3. Hydrogen is adsorbed by a palladium-based alloy coated on the inner wall surface of a first spiral tube 13, and the concentration of hydrogen can be determined by the pressure difference after the hydrogen is adsorbed, thereby reducing the concentration of hydrogen and the risk of combustion and explosion. In addition, the use of an oxygen analyzer 17 to analyze the concentration of oxygen can more accurately determine whether the gas is flammable, thereby improving the safety and reliability of the system.

[0038] The device of the present invention is not limited to the embodiments in the specific implementation manner. As long as a person skilled in the art can derive other implementation manners based on the technical solution of the present invention, they also fall within the scope of technical innovation and protection of the present invention.

Claims

1. A system for analyzing the flammability of gas in a containment vessel, characterized in that: It includes a sampling probe, a sampling valve, a water vapor sensor, a water vapor condensation device, a pressure sensor, a condensate collection valve, a condensate tank, a measurement front valve, a first circulation vacuum pump, a vacuum valve, a vacuum pump, a first spiral tube inlet valve, a first spiral tube, a first spiral tube pressure sensor, a first spiral tube outlet valve, a second circulation vacuum pump and an oxygen analyzer; the sampling probe, the sampling valve, the water vapor sensor, the water vapor condensation device, the measurement front valve, the first circulation vacuum pump, the first spiral tube inlet valve, the first spiral tube, the first spiral tube outlet valve, the second circulation vacuum pump and the The oxygen analyzer is connected in sequence through pipelines; a water outlet is provided at the bottom of the water vapor condensing device, and the water outlet is connected in sequence with the condensed water collecting valve and the condensed water tank; a gas-liquid isolation plate is provided in the water vapor condensing device, and the gas-liquid isolation plate is located above the water outlet; the vacuum pump and the vacuum valve are connected in sequence with the water vapor condensing device; the pressure sensor is provided on the water vapor condensing device; the first spiral tube pressure sensor is provided on the first spiral tube; the inner wall surface of the first spiral tube is coated with a palladium-based alloy, and an electric heating device is installed on the outer wall surface of the first spiral tube; The water vapor is collected by the water vapor condensation device, and the amount of the water vapor is measured by the water vapor sensor; the hydrogen is adsorbed by the palladium-based alloy coated on the inner wall of the first spiral tube, and the concentration of the hydrogen is determined by the pressure difference after the hydrogen is adsorbed; The oxygen concentration is analyzed by the oxygen analyzer.

2. The containment gas flammability analysis system according to claim 1, characterized in that: It also includes a gas recovery valve and a gas recovery pump, one end of the gas recovery valve is connected to the oxygen analyzer, the other end of the gas recovery valve is connected to one end of the gas recovery pump, and the other end of the gas recovery pump is used to connect to the containment shell.

3. The containment gas flammability analysis system according to claim 2, characterized in that: It also includes a second spiral tube inlet valve, a second spiral tube, a second spiral tube pressure sensor and a second spiral tube outlet valve, the second spiral tube inlet valve, the second spiral tube and the second spiral tube outlet valve are connected in sequence, the second spiral tube inlet valve is connected to the vacuum pump, the second spiral tube outlet valve is connected to the second circulating vacuum pump, and the second spiral tube pressure sensor is arranged on the second spiral tube; the inner wall surface of the second spiral tube is coated with a palladium-based alloy, and the outer wall surface of the second spiral tube is installed with another electric heating device.

4. The containment gas flammability analysis system according to claim 3, characterized in that: It also includes a first spiral tube front purge valve, a first spiral tube rear purge valve and a high-pressure inert gas tank, wherein the high-pressure inert gas tank is connected to one end of the first spiral tube front purge valve, the other end of the first spiral tube front purge valve is connected to the pipeline between the first spiral tube inlet valve and the first spiral tube, one end of the first spiral tube rear purge valve is connected to the pipeline between the first spiral tube and the first spiral tube outlet valve, and the other end of the first spiral tube rear purge valve is connected to the pipeline between the gas recovery valve and the gas recovery pump.

5. The containment gas flammability analysis system according to claim 4, characterized in that: It also includes a second spiral tube purge front valve and a second spiral tube purge rear valve, one end of the second spiral tube purge front valve is connected to the high-pressure inert gas tank, the other end of the second spiral tube purge front valve is connected to the pipeline between the second spiral tube inlet valve and the second spiral tube, one end of the second spiral tube purge rear valve is connected to the pipeline between the second spiral tube and the second spiral tube outlet valve, and the other end of the second spiral tube purge rear valve is connected to the pipeline between the gas recovery valve and the gas recovery pump.

6. The containment gas flammability analysis system according to claim 5, characterized in that: It also includes a condensate backflush valve, one end of which is connected to the high-pressure inert gas tank, and the other end of which is connected to a pipeline between the condensate collection valve and the condensate tank.

7. The system for analyzing the flammability of gas in a containment vessel according to claim 6, characterized in that: It also includes a condensate discharge valve, one end of which is connected to the condensate tank, and the other end of which is connected to the containment shell.

8. The containment gas flammability analysis system according to claim 6, characterized in that: It also includes a condensate tank level gauge, which is connected to the condensate tank and arranged on the condensate tank.

9. The system for analyzing the flammability of gas in a containment vessel according to any one of claims 3 to 8, characterized in that: The electric heating device is an electric heating belt or a conductive heating film.

10. The system for analyzing the flammability of gas in a containment vessel according to any one of claims 1 to 8, characterized in that: There are a plurality of the sampling probes and the sampling valves, and the plurality of the sampling probes and the plurality of the sampling valves are connected in a one-to-one correspondence, and the plurality of the sampling valves are all connected to the water vapor sensor.

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