Containment gas circulation dehydrogenation system and method with multiple drive sources

Abstract

The application discloses a containment gas circulation hydrogen removal system and method with multiple driving sources, which comprises a reactor pressure vessel in a containment, wherein the outer side of the reactor pressure vessel is provided with a pressure vessel compartment, the left side of the pressure vessel compartment is provided with a steam generator, the outer side of the steam generator is provided with a steam generator compartment, the right side of the pressure vessel compartment is provided with a pressure stabilizer, the outer side of the pressure stabilizer is provided with a pressure stabilizer compartment, one injection tank is arranged on the steam generator compartment and the pressure stabilizer compartment respectively, the reactor pressure vessel is connected with the injection tanks through two water injection pipelines, one heat exchanger is arranged on the upper side of the containment of the steam generator compartment and the upper side of the containment of the pressure stabilizer compartment respectively, and a circumferential spraying device is arranged between the heat exchangers. The device can prevent hydrogen concentration from being too large to cause combustion and explosion, and ensure the integrity of the containment under accident conditions.

Description

Technical Field

[0001] This invention relates to the field of nuclear power technology, and in particular to a containment gas circulation and hydrogen removal system and method with multiple drive sources. Background Technology

[0002] Nuclear energy, as a clean energy source, has enormous development potential and promising applications. However, the potential harm to the environment and society from the leakage of radioactive materials must be considered. Therefore, as the third and final line of defense against radioactive material leakage, the integrity of the containment vessel must be effectively guaranteed. When a breach occurs in the reactor's primary circuit, causing a serious accident, the breach will release a large amount of steam. Simultaneously, due to the zirconium-water reaction, a large amount of hydrogen will be released into the compartments and even the large space of the containment vessel. When the hydrogen concentration reaches a certain level, a combustion explosion may occur, severely damaging the integrity of the containment vessel. In my country's "Hualong One" nuclear power plant, which possesses completely independent intellectual property rights, multiple active and passive safety measures are implemented. Among them, the passive containment hydrogen removal system eliminates hydrogen through catalytic recombination in the event of an accident, limiting the hydrogen concentration within the containment vessel to below the combustion explosion limit. However, in order to make the various systems of the nuclear power plant operate more effectively and further ensure the integrity of the containment under severe accident conditions, it is necessary to design a reasonable and feasible layout scheme based on the characteristics of the released gases under accident conditions, to promote the circulation of gases in the large space of the containment and avoid the possible phenomenon of excessively high hydrogen concentration.

[0003] Several patents in existing design applications have also considered the gases inside the containment under severe accident conditions. Patent CN201921360086.3 provides a small modular reactor (SMR) safety protection system that stores cooled gas in a wet well gas space above the pressure relief pool inside the containment, and introduces hydrogen into the hydrogen-oxygen recombiner through a connecting valve, preventing potential combustion and explosion within the containment. However, this design is applicable to SMRs and cannot be directly applied to other reactor types. Patent CN201110129066.7 designs a device to mitigate severe nuclear accidents and prevent hydrogen explosions by continuously adsorbing and igniting hydrogen to reduce the hydrogen concentration inside the containment. However, this design only considers the arrangement of the hydrogen recombiner and does not take into account the role of other equipment within the large containment space. Patent CN202110244976.3 designs a containment heat exchanger using a gas storage compartment, which reduces the content of non-condensable gases around the heat transfer tubes and in the upper part of the containment through a shear-type suction system and the gas storage compartment, preventing overheating and overpressure phenomena within the containment. However, this design failed to further optimize the layout of the internal compartments of the containment based on the low density of hydrogen. Current designs primarily focus on improving hydrogen removal capabilities through modifications to a single device, without considering the importance of creating circulation within the large containment space for hydrogen dissipation, or the crucial role of this large-space circulation in improving equipment operating efficiency. Summary of the Invention

[0004] The technical problem to be solved by the present invention is how to provide a containment gas circulation hydrogen removal system that can prevent excessive hydrogen concentration from causing combustion and explosion and ensure the integrity of the containment under accident conditions.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a containment gas circulation hydrogen removal system with multiple driving sources, characterized in that it includes: a reactor pressure vessel located inside the containment; a pressure vessel compartment is provided on the outside of the reactor pressure vessel; an outlet is provided on the pressure vessel compartment; a steam generator is provided on the left side of the pressure vessel compartment; a steam generator compartment is provided on the outside of the steam generator; a pressurizer is provided on the right side of the pressure vessel compartment; a pressurizer compartment is provided on the outside of the pressurizer; and an outlet and an inlet are respectively formed on the upper and lower sides of the steam generator compartment and the pressurizer compartment. A hydrogen recombiner is installed in the upper outlet of the steam generator compartment and the upper outlet of the pressurizer compartment, respectively. A safety injection tank is installed on the steam generator compartment and the pressurizer compartment, respectively. The reactor pressure vessel is connected to the safety injection tank through two water injection pipelines. A heat exchanger is installed on the containment vessel on the upper side of the steam generator compartment and the containment vessel on the upper side of the pressurizer compartment, respectively. A circumferential spray device is installed between the heat exchangers.

[0006] This invention also discloses a method for hydrogen removal from containment gas circulation with multiple drive sources. The method uses the aforementioned containment gas circulation hydrogen removal system and includes the following steps:

[0007] When a rupture occurs in the pipeline of the pressure vessel compartment, the ruptured gas flows from above the pressure vessel compartment into the large space of the containment and spreads outwards. The top circumferential spray system is activated to reduce the pressure and temperature inside the containment and, by adjusting the nozzle angle, directs the gas towards the heat exchangers on both sides of the walls. The gas on the left flows through the heat exchanger on the left, where some of the steam condenses on the surface of the heat exchanger and flows towards the lower part of the containment under the effect of sedimentation, merging with the low-temperature gas around the water injection pipeline. Subsequently, some of the gas enters the steam generator compartment, where it is heated into high-temperature, low-density gas by the steam generator, which acts as a heat source. Under the action of buoyancy, it flows out from the vertical section at the top of the steam generator compartment, where some of the hydrogen is eliminated by the hydrogen-oxygen reaction in the hydrogen recombination device of the vertical section. Another part of the gas flows into the pressure vessel compartment, is heated by the reactor pressure vessel, and flows out from the top of the compartment under the action of buoyancy, thus recirculating.

[0008] The gas on the right flows towards the lower part of the containment under the action of the heat exchanger on the right. A portion of the gas enters the pressure relief tank compartment and is heated by the pressure relief tank. Then it flows into the pressure relief tank compartment and is heated by the pressure regulator. Under the action of buoyancy, it flows out from the vertical outlet section at the top of the pressure relief tank compartment. The hydrogen recombiner arranged here eliminates hydrogen through the hydrogen-oxygen reaction. The other portion of the gas enters the pressure vessel compartment and flows out from the top of the compartment under the action of buoyancy to circulate again.

[0009] When a rupture occurs in the steam generator compartment piping, the ruptured gas flows out along the vertical channel above the compartment, and the gas circulation formed in the large containment space is consistent with the gas circulation formed in the left half of the containment space when the pressure vessel compartment ruptures; when a rupture occurs in the pressurizer compartment piping, the gas flows out from the vertical channel of the outlet above the compartment, and the gas circulation formed is consistent with the gas circulation formed in the right half of the containment space when the pressure vessel compartment ruptures.

[0010] The beneficial effects of adopting the above technical solution are as follows: Taking into account the location of the main equipment such as heat exchangers, steam generators, and pressure stabilizers in the large space of the containment, the present invention promotes the circulation of gas in the large space through reasonable arrangement, prevents excessive hydrogen concentration from causing combustion and explosion, and ensures the integrity of the containment under accident conditions.

[0011] Placing the safety injection tank on top of the steam generator compartment and the pressurizer compartment makes effective use of the compartments, while the water injection line between the safety injection tank and the reactor pressure vessel serves as a cold source and promotes gas circulation in the lower containment space.

[0012] The circumferential spray device promotes the flow of gas towards the heat exchangers on both sides by adjusting the nozzle angle, thereby enhancing the circulation of gas in the large space of the containment.

[0013] Taking advantage of the low density of hydrogen, the hydrogen recombiner is placed in the upper vertical channel of the steam generator compartment and the pressure regulator compartment. This not only improves the hydrogen recombining efficiency but also promotes gas circulation by utilizing the chimney effect. Attached Figure Description

[0014] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0015] Figure 1 This is a schematic block diagram of the system described in the embodiment of the present invention;

[0016] The components include: 1. Reactor pressure vessel; 2. Pressure vessel compartment; 3. Containment; 4. Circumferential spray system; 5. Heat exchanger; 6. Safety injection tank; 7. Steam generator; 8. Water injection pipeline; 9. Steam generator compartment; 10. Depressurization tank; 11. Pressurizer; 12. Pressurizer compartment; 13. Hydrogen recombiner. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0018] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0019] like Figure 1As shown in the figure, this invention discloses a containment gas circulation hydrogen removal system with multiple drive sources, including: a reactor pressure vessel 1 located inside a containment 3; a pressure vessel compartment 2 disposed on the outside of the reactor pressure vessel 1; a gas outlet disposed on the pressure vessel compartment 2; a steam generator 7 disposed on the left side of the pressure vessel compartment 2; a steam generator compartment 9 disposed on the outside of the steam generator 7; a pressurizer 11 disposed on the right side of the pressure vessel compartment 2; a pressurizer compartment 12 disposed on the outside of the pressurizer 11; and gas outlets and gas inlets formed on the upper and lower sides of the steam generator compartment 9 and the pressurizer compartment 12, respectively. A hydrogen recombiner 13 is installed in the upper outlet of the steam generator compartment 9 and the upper outlet of the pressurizer compartment 12, respectively. A safety injection tank 6 is installed on the steam generator compartment 9 and the pressurizer compartment 12, respectively. The reactor pressure vessel 1 is connected to the safety injection tank 6 through two water injection pipelines 8. A heat exchanger 5 is installed on the containment vessel 3 on the upper side of the steam generator compartment 9 and the containment vessel 3 on the upper side of the pressurizer compartment 12, respectively. A circumferential spray device 4 is installed between the heat exchangers 5. The pressure relief tank 10 is located outside the lower air inlet of the pressurizer compartment 12.

[0020] In this application, the circumferential spray device 4 is located at the top of the large space of the containment, and is used to reduce the pressure inside the containment under severe accident conditions and ensure the integrity of the containment. The nozzles of the circumferential spray device 4 have a certain angle, with the middle nozzle pointing downward to enhance the mixing effect with the gas at the breach, the left nozzle pointing slightly to the left, and the right nozzle pointing slightly to the right. By spraying towards the heat exchangers on both sides of the wall, the circulation of gas is promoted.

[0021] The heat exchangers 5 are symmetrically arranged in the upper region of the containment. The surface of the heat exchangers condenses some of the steam and guides the gas to flow into the lower space of the containment. The upper part of the steam generator compartment 9 is equipped with a safety injection box, and the upper outlet channel of the compartment is set as a vertical section to promote the circulation of gas in the large space of the containment by utilizing the chimney effect. The upper part of the pressurizer compartment 12 is equipped with a safety injection box 6, and the upper outlet channel of the compartment is set as a vertical section to promote the circulation of gas in the large space of the containment by utilizing the chimney effect.

[0022] A hydrogen recombination device is installed in the vertical section of the steam generator compartment 9 to eliminate hydrogen through a hydrogen-oxygen reaction, preventing the hydrogen concentration inside the containment from reaching the combustion and explosion limit. A water injection line 8 is arranged between the upper injection tank 6 of the steam generator compartment 9 and the reactor pressure vessel 1. The water injection line 8 is distributed along the outer wall of the compartment, ensuring that the line is located in the area through which the mixed gas flows. The water injection line 8 not only injects cooling water into the reactor core but also acts as a cold source to allow nearby low-temperature, high-density gases to merge with the flowing mixed gas, promoting gas circulation within the large containment space.

[0023] A hydrogen recombiner 13 is installed in the vertical section of the pressurizer compartment 12 to eliminate hydrogen through a hydrogen-oxygen reaction, preventing the hydrogen concentration inside the containment from reaching the combustion and explosion limit. A water injection pipeline 8 is arranged along the outside of the pressurizer compartment 12 between the upper injection tank 6 and the reactor pressure vessel 1. The water injection pipeline 8 is distributed along the outer wall of the compartment, ensuring that the pipeline is located in the area through which the mixed gas flows. The water injection pipeline not only injects cooling water into the reactor core but also acts as a cold source, allowing nearby low-temperature, high-density gases to merge with the flowing mixed gas, promoting gas circulation within the large containment space.

[0024] Accordingly, embodiments of the present invention also disclose a method for hydrogen removal from containment gas circulation with multiple drive sources. The method uses the aforementioned containment gas circulation hydrogen removal system and includes the following steps:

[0025] When a rupture occurs in the pipeline of pressure vessel compartment 2, the ruptured gas flows from above pressure vessel compartment 2 into the large space of containment 3 and spreads outwards. The top circumferential spray device 4 is put into operation to reduce the pressure and temperature inside the containment and to make the gas flow near the heat exchangers on both sides of the wall by adjusting the nozzle angle. The gas on the left flows through the heat exchanger 5 on the left side, and some of the steam condenses on the surface of the heat exchanger 5 on the left side. Under the action of the settling effect, it flows into the lower part of the containment and merges with the low temperature gas around the water injection pipeline 8. Then, some of the gas enters the steam generator compartment 9 and is heated into high temperature and low density gas by the steam generator 7, which acts as a heat source. Under the action of buoyancy, it flows out from the vertical section at the top of the steam generator compartment 9. Some of the hydrogen flowing through is eliminated by the hydrogen recombination device 13 in the vertical section through the hydrogen-oxygen reaction. Another part of the gas flows into pressure vessel compartment 2, is heated by reactor pressure vessel 1, and flows out from the top of the compartment under the action of buoyancy, and is circulated again.

[0026] The gas on the right side flows towards the lower part of the containment under the action of the heat exchanger 5 on the right side. A part of the gas enters the pressure relief tank 10 and is heated by the pressure relief tank 10. Then it flows to the pressure relief tank 12 and is heated by the pressure regulator 11. Under the action of buoyancy, it flows out from the upper vertical outlet section of the pressure regulator tank 12. The hydrogen recombiner 13 arranged here eliminates hydrogen through hydrogen-oxygen reaction. The other part of the gas enters the pressure vessel compartment 2 and flows out from the top of the compartment under the action of buoyancy to circulate again.

[0027] When a rupture occurs in the pipe of steam generator compartment 9, the ruptured gas flows out along the vertical channel above the compartment, and the gas circulation formed in the large space of the containment is consistent with the gas circulation formed in the left half space of the containment when pressure vessel compartment 2 ruptures; when a rupture occurs in the pipe of pressurizer compartment 12, the gas flows out from the vertical channel of the outlet above the compartment, and the gas circulation formed is consistent with the gas circulation formed in the right half space of the containment when pressure vessel compartment 2 ruptures.

[0028] This invention takes into account the location of major equipment such as heat exchangers, steam generators, and pressure regulators within the large containment space. By rationally arranging these components, it promotes the circulation of gas within the large space, prevents excessive hydrogen concentration from causing combustion and explosion, and ensures the integrity of the containment under accident conditions.

Claims

1. A containment gas circulation and hydrogen removal system with multiple drive sources, characterized in that... include: A reactor pressure vessel (1) is located inside the containment vessel (3). A pressure vessel compartment (2) is provided on the outside of the reactor pressure vessel (1). An outlet is provided on the pressure vessel compartment (2). A steam generator (7) is provided on the left side of the pressure vessel compartment (2). A steam generator compartment (9) is provided on the outside of the steam generator (7). A pressurizer (11) is provided on the right side of the pressure vessel compartment (2). A pressurizer compartment (12) is provided on the outside of the pressurizer (11). An outlet and an inlet are formed on the upper and lower sides of the steam generator compartment (9) and the pressurizer compartment (12), respectively. A hydrogen recombiner (13) is installed in the upper outlet of the steam generator compartment (9) and the upper outlet of the pressurizer compartment (12). A safety injection tank (6) is installed on the steam generator compartment (9) and the pressurizer compartment (12). The reactor pressure vessel (1) is connected to the safety injection tank (6) through two water injection pipelines (8). A heat exchanger (5) is installed on the containment vessel (3) on the upper side of the steam generator compartment (9) and the containment vessel (3) on the upper side of the pressurizer compartment (12). A circumferential spray device (4) is installed between the heat exchangers (5). The system also includes a pressure relief box (10), which is located outside the lower air inlet of the pressure regulator compartment (12); the nozzles of the circumferential spray device (4) are angled, with the middle nozzle pointing downwards to enhance the mixing with the gas at the break point, the left nozzle pointing slightly to the left, and the right nozzle pointing slightly to the right, promoting the circulation of gas by spraying towards the heat exchangers on both sides of the wall; the heat exchangers (5) are symmetrically arranged in the upper region of the containment (3), and some steam is condensed on the surface of the heat exchangers (5), guiding the gas to flow into the lower space of the containment (3); the upper air outlet of the steam generator compartment (9) is connected to the air inlet of the steam generator compartment (9). The channel is set as a vertical section, which uses the chimney effect to promote the circulation of gas in the large space of the containment. The outlet channel at the top of the pressure regulator compartment (12) is set as a vertical section, which uses the chimney effect to promote the circulation of gas in the large space of the containment. The lower part of the pressure regulator compartment (12) is provided with two layers of baffles, each baffle forming an air inlet, and the air inlets on the two baffles are staggered. The water injection pipeline (8) is distributed along the outer wall of the steam generator compartment (9) and the outer wall of the pressure regulator compartment (12). There are two outlets on the pressure vessel compartment (2), located on the left and right sides of the pressure vessel (1).

2. A method for hydrogen removal from containment gas circulation with multiple drive sources, the method using the containment gas circulation hydrogen removal system as described in claim 1, characterized in that... Includes the following steps: When a rupture occurs in the pipeline of the pressure vessel compartment (2), the ruptured gas flows from above the pressure vessel compartment (2) into the large space of the containment (3) and spreads outwards. The top circumferential spray device (4) is put into operation to reduce the pressure and temperature inside the containment and to make the gas flow to the vicinity of the heat exchangers on both sides of the wall by adjusting the nozzle angle. The gas on the left flows through the heat exchanger (5) on the left side, and some of the steam condenses on the surface of the heat exchanger (5) on the left side. Under the action of the settling effect, it flows to the lower part of the containment and mixes with the gas. Low-temperature gases around the water pipeline (8) converge; then a portion of the gas enters the steam generator compartment (9), is heated by the steam generator (7) as a heat source into high-temperature, low-density gas, and flows out from the vertical section above the steam generator compartment (9) under the action of buoyancy. A portion of the hydrogen gas that flows through is eliminated by the hydrogen recombination device (13) in the vertical section through the hydrogen-oxygen reaction; another portion of the gas flows into the pressure vessel compartment (2), is heated by the reactor pressure vessel (1), and flows out from the top of the compartment under the action of buoyancy, and is circulated again; The gas on the right side flows towards the lower part of the containment under the action of the heat exchanger (5) on the right side. A part of the gas enters the pressure relief tank (10) and is heated by the pressure relief tank (10). Then it flows to the pressure relief tank (12) and is heated by the pressure regulator (11). Under the action of buoyancy, it flows out from the upper vertical outlet section of the pressure regulator tank (12). The hydrogen recombiner (13) arranged here eliminates hydrogen through the hydrogen-oxygen reaction. The other part of the gas enters the pressure vessel compartment (2) and flows out from the top of the compartment under the action of buoyancy to circulate again. When the pipe in the steam generator compartment (9) breaks, the gas from the break flows out along the vertical channel above the compartment, and the gas circulation formed in the large space of the containment is consistent with the gas circulation formed in the left half space of the containment when the pressure vessel compartment (2) breaks; when the pipe in the pressure regulator compartment (12) breaks, the gas flows out from the vertical channel of the outlet above the compartment, and the gas circulation formed is consistent with the gas circulation formed in the right half space of the containment when the pressure vessel compartment (2) breaks.

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