A hydrogen recombiner employing a water-drop shaped catalytic element and a method of operation thereof

Abstract

The application provides a hydrogen recombiner with water-drop-shaped catalytic elements and a working method thereof, and belongs to the technical field of hydrogen safety in the nuclear energy industry. The hydrogen recombiner with water-drop-shaped catalytic elements comprises a catalytic channel and a catalytic element layer. The catalytic channel is sequentially provided with an inlet, a high-speed catalytic section, a chimney section and an outlet. The catalytic element layer is arranged in the high-speed catalytic section. The catalytic element layer comprises a plurality of catalytic elements arranged at intervals. The catalytic elements are in the shape of water drops. The hydrogen recombiner with water-drop-shaped catalytic elements can effectively improve the hydrogen removal performance and hydrogen removal efficiency of the hydrogen recombiner as a whole, reduce the flow resistance in the device, better maintain the establishment of natural circulation flow, and further improve the comprehensive performance of the hydrogen recombiner.

Description

TECHNICAL FIELD

[0001] The present application belongs to the hydrogen safety technical field of nuclear power industry, and particularly relates to a hydrogen recombiner adopting water-drop-shaped catalytic elements and a working method thereof. BACKGROUND

[0002] In a pressurized water reactor nuclear power plant, when the coolant is lost due to accidents such as loss of off-site power, high-temperature water vapor in the primary loop will leak into the containment of the nuclear power plant. Among them, the zirconium alloy cladding constituting the nuclear fuel assembly will react violently with the water vapor to produce a large amount of hydrogen and be discharged into the containment.

[0003] The gas composition in the containment under normal conditions is air, which is not flammable. However, as a large amount of hydrogen is released into the containment and mixed with water vapor and air. When the hydrogen concentration reaches the flammable limit, flammable gas will be formed, and different degrees of hydrogen explosion phenomena will occur according to the hydrogen concentration. Hydrogen explosion will damage the integrity of the containment, and under accident conditions, it will cause radioactive material to be released into the environment, causing irreversible damage to external residents and the environment, and posing a great threat to local personnel and the environment.

[0004] Earthquakes can cause nuclear power plant units to lose power and, through a series of chain effects, eventually result in hydrogen explosions in the containment, ultimately damaging the structure of the containment, and the roof of the containment is blown through. Nuclear safety agencies around the world attach great importance to the behavior of hydrogen in the containment under severe accident conditions of nuclear power plants. In order to effectively deal with the potential hydrogen risk in the containment, the development and application of hydrogen mitigation measures need to be put on the agenda. Existing hydrogen mitigation measures include: pre-accident inerting, post-accident inerting, ventilation, dilution, active ignition, hydrogen recombination, etc.

[0005] Among them, the product derived from hydrogen recombination technology, passive hydrogen recombiner, has been widely used in recent years. Passive hydrogen recombiner has the advantages of no need for external energy supply, operation at room temperature and low concentration, no moving parts, passive characteristics and good hydrogen removal capacity, and has gradually become a widely used severe accident hydrogen removal equipment for nuclear power plants in the world. The device uses a noble metal catalyst covering the surface of the catalytic element to induce a chemical reaction, so that the hydrogen and oxygen released in the containment react on the surface of the catalyst, and the reaction heat of the catalytic reaction makes the gas flow continuously inside the device, forming a "chimney effect" and forming a natural circulation to maintain the continuous operation of the device. However, the flow resistance in the device of the passive hydrogen recombiner in the prior art is large, and the hydrogen removal capacity is insufficient. SUMMARY

[0006] Therefore, in order to solve the problem of large flow resistance in the device of the passive hydrogen recombiner in the prior art and insufficient hydrogen removal capacity, the application provides a hydrogen recombiner adopting water-drop-shaped catalytic elements and a working method thereof.

[0007] To achieve the above object, the application adopts the following technical scheme.

[0008] A hydrogen recombiner adopting water-drop-shaped catalytic elements comprises:

[0009] A catalytic channel is sequentially provided with an inlet, a high-speed catalytic section, a chimney section and an outlet.

[0010] A catalytic element layer is arranged in the high-speed catalytic section, and the catalytic element layer comprises a plurality of catalytic elements arranged at intervals, and the catalytic elements are in the shape of water drops.

[0011] As a preferred scheme of the hydrogen recombiner adopting water-drop-shaped catalytic elements, the number of the catalytic element layers is 1, 2 or more, and the two or more catalytic element layers are arranged at intervals along the extension direction of the catalytic channel.

[0012] As a preferred scheme of the hydrogen recombiner adopting water-drop-shaped catalytic elements, the plurality of catalytic elements in the catalytic element layer are arranged in an m*n array, where m and n are positive integers.

[0013] As a preferred scheme of the hydrogen recombiner adopting water-drop-shaped catalytic elements, the plurality of catalytic elements in the catalytic element layer are arranged in a circular array.

[0014] As a preferred scheme of the hydrogen recombiner adopting water-drop-shaped catalytic elements, the three-dimensional streamline solid structure of the catalytic element is formed based on a two-dimensional streamline, with the central axis as the axis and rotation of 360°.

[0015] The application further provides a working method of the hydrogen recombiner adopting water-drop-shaped catalytic elements, which adopts the hydrogen recombiner adopting water-drop-shaped catalytic elements, and the specific steps comprise:

[0016] S1: hydrogen and air enter the high-speed catalytic section from the inlet, and catalytic reaction occurs on the outer surfaces of the plurality of catalytic elements to generate water vapor and release heat;

[0017] S2: natural convection is formed in the chimney section.

[0018] S3: air and water vapor flow out of the outlet.

[0019] As a preferred scheme of the working method of the hydrogen recombiner adopting water-drop-shaped catalytic elements, the gas in the catalytic channel flows stably and the flow field is uniformly distributed.

[0020] As a preferred solution of the working method of the hydrogen gas combiner with water-drop-shaped catalytic elements, S0 is further included before S1, S0: according to the required hydrogen removal capacity and the change of flow resistance, the number, spacing, arrangement angle and arrangement mode of the catalytic elements in the high-speed catalytic section are determined.

[0021] As a preferred solution of the working method of the hydrogen gas combiner with water-drop-shaped catalytic elements, the arrangement mode of the catalytic element layer is stacking type or hollow type.

[0022] As a preferred solution of the working method of the hydrogen gas combiner with water-drop-shaped catalytic elements, the arrangement mode of the catalytic element layer is regular or irregular.

[0023] Compared with the prior art, the hydrogen gas combiner with water-drop-shaped catalytic elements and the working method thereof provided by the application have the following beneficial effects:

[0024] The application provides a hydrogen gas combiner with water-drop-shaped catalytic elements and a working method thereof. In the hydrogen gas combiner with water-drop-shaped catalytic elements, a plurality of catalytic elements are arranged in a catalytic element layer in a catalytic channel, the catalytic elements are water-drop-shaped, hydrogen gas and air enter from an inlet, and a catalytic reaction occurs on the outer surface of the catalytic elements in a high-speed catalytic section, a large amount of heat is released while water vapor is generated, natural convection is formed in a chimney section, and finally the hydrogen gas flows out from an outlet, enters the inlet again, and circulates repeatedly to remove hydrogen. Based on the chemical properties and the structural characteristics of the catalytic elements, compared with other hydrogen gas combiners based on traditional structures, the hydrogen gas combiner with water-drop-shaped catalytic elements can effectively improve the hydrogen removal capacity and the hydrogen removal efficiency, and improve the utilization rate of the catalyst. Moreover, the structure can maintain stable and uniform flow field distribution, and does not cause phenomena such as boundary layer separation and vortex. Compared with other hydrogen gas combiners based on traditional structures, the flow resistance of the hydrogen gas combiner with water-drop-shaped catalytic elements is much smaller than that of the traditional structure hydrogen gas combiner. Therefore, the hydrogen gas combiner with water-drop-shaped catalytic elements can effectively improve the hydrogen removal performance and the hydrogen removal efficiency of the hydrogen gas combiner as a whole, reduce the flow resistance in the device, better maintain the establishment of natural circulation flow, and further improve the comprehensive performance of the hydrogen gas combiner. BRIEF DESCRIPTION OF DRAWINGS

[0025] The accompanying drawings, which form a part of the present application, are intended to provide further understanding of the present application, and are used to interpret the specific embodiments of the present application and their descriptions, and do not constitute improper limitations on the present application. In the drawings:

[0026] Figure 1 is a structural schematic view of the hydrogen gas combiner with water-drop-shaped catalytic elements provided by the specific embodiments of the present application;

[0027] Figure 2 is a structural schematic diagram of a catalytic element of a hydrogen recombiner with water-drop-shaped catalytic elements provided by specific embodiments of the present application;

[0028] Figure 3 is a structural schematic diagram of a single-layer catalytic element layer of a hydrogen recombiner with water-drop-shaped catalytic elements provided by specific embodiments of the present application;

[0029] Figure 4 is a structural schematic diagram of a two-layer catalytic element layer of a hydrogen recombiner with water-drop-shaped catalytic elements provided by specific embodiments of the present application;

[0030] Figure 5 is a structural schematic diagram of a multi-layer catalytic element layer of a hydrogen recombiner with water-drop-shaped catalytic elements provided by specific embodiments of the present application;

[0031] Figure 6 is a structural schematic diagram of a catalytic element layer of a hydrogen recombiner with water-drop-shaped catalytic elements provided by specific embodiments of the present application, in which the arrangement mode is a stacking type;

[0032] Figure 7 is a structural schematic diagram of a catalytic element layer of a hydrogen recombiner with water-drop-shaped catalytic elements provided by specific embodiments of the present application, in which the arrangement mode is a hollow type, and the view is along a first view angle;

[0033] Figure 8 is a structural schematic diagram of a catalytic element layer of a hydrogen recombiner with water-drop-shaped catalytic elements provided by specific embodiments of the present application, in which the arrangement mode is a hollow type, and the view is along a second view angle.

[0034] In the figure:

[0035] 1, inlet; 2, outlet; 3, catalytic element layer; 31, catalytic element. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other, and the described embodiments are only some of the embodiments of the present application, but not all the embodiments.

[0037] In the description of the present application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0038] In the present application, unless otherwise explicitly specified and limited, "on" or "under" the first feature of the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the first feature is higher in horizontal height than the second feature. The first feature "under", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the first feature is lower in horizontal height than the second feature.

[0039] In the description of the present embodiment, the terms "up", "down", "right", and other orientation or position relationships shown in the drawings are based on the orientation or position relationship shown in the drawings, only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only used to distinguish in the description, and have no special meaning.

[0040] Referring to Figures 1-8 In order to illustrate the present application, the present application provides a hydrogen recombiner with water-drop-shaped catalytic elements and a working method thereof. The hydrogen recombiner with water-drop-shaped catalytic elements comprises a catalytic channel and a catalytic element layer 3. The catalytic channel is sequentially provided with an inlet 1, a high-speed catalytic section, a chimney section and an outlet 2. The catalytic element layer 3 is arranged in the high-speed catalytic section. The catalytic element layer 3 comprises a plurality of catalytic elements 31 arranged at intervals. The catalytic elements 31 are in the shape of water drops.

[0041] The hydrogen recombiner with water-drop-shaped catalytic elements has a plurality of catalytic elements 31 in the catalytic element layer 3 in the catalytic channel, the catalytic elements 31 are water-drop-shaped, hydrogen and air enter from the inlet 1 and are catalyzed in the high-speed catalytic section, a catalytic reaction occurs on the outer surface of the catalytic elements 31, a large amount of heat is released while water vapor is generated, natural convection is formed in the chimney section, and finally flows out from the outlet 2. The hydrogen enters from the inlet 1 again and circulates repeatedly to consume hydrogen. Based on the chemical properties and the structural characteristics of the catalytic elements 31, compared with other hydrogen recombiners based on traditional structures, the hydrogen recombiner with water-drop-shaped catalytic elements can effectively improve the hydrogen consumption capacity and efficiency and improve the utilization rate of the catalyst. Moreover, the structure can maintain stable and uniform flow field distribution without boundary layer separation and vortex and the like. Compared with other hydrogen recombiners based on traditional structures, the flow resistance of the hydrogen recombiner with water-drop-shaped catalytic elements 31 is much smaller than that of the traditional structure hydrogen recombiner. Therefore, the hydrogen recombiner with water-drop-shaped catalytic elements can effectively improve the overall hydrogen consumption performance and efficiency of the hydrogen recombiner and reduce the flow resistance inside the device, better maintain the establishment of natural circulation flow, and further improve the comprehensive performance of the hydrogen recombiner.

[0042] It can be understood that the bottom area of the water-drop-shaped catalytic element 31 is large, and the hydrogen enters from the inlet 1 and first contacts the bottom of the catalytic element 31.

[0043] Optionally, the number of the catalytic element layers 3 is 1, 2 or more, and the two or more catalytic element layers 3 are arranged at intervals along the extension direction of the catalytic channel. The arrangement mode of the catalytic element 31 is diversified, and one, two or more catalytic element layers 3 can be arranged. When the catalytic element layer 3 is two or more layers, the two or more catalytic element layers 3 are arranged at intervals along the extension direction of the catalytic channel.

[0044] As shown in Figure 3 , Figure 4 , Figure 5 and Figure 6 , optionally, the plurality of catalytic elements 31 in the catalytic element layer 3 are arranged in an m*n array, where m and n are positive integers.

[0045] As shown in Figure 7 and Figure 8 , optionally, the plurality of catalytic elements 31 in the catalytic element layer 3 are arranged in a circular array.

[0046] Optionally, the three-dimensional streamline solid structure of the catalytic element 31 is formed based on a two-dimensional streamline, with the central axis as the axis and rotated by 360°. The outer surface line of the catalytic element 31 is smooth, the gas flow around the catalytic element 31 is stable, the flow field distribution is uniform, and no severe boundary layer separation phenomenon occurs.

[0047] The application further provides a working method of the hydrogen recombiner with water-drop-shaped catalytic elements.

[0048] S0: According to the required hydrogen removal capacity and flow resistance change, the number, spacing, arrangement angle and arrangement mode of the catalytic elements 31 in the high-speed catalytic section are determined. In order to cope with different hydrogen removal capacities and flow resistance changes, the arrangement mode of the water-drop-shaped catalytic elements 31, the shape of the water-drop-shaped catalytic elements 31, the material of the catalyst, etc. can be adjusted.

[0049] S1: Hydrogen and air enter the high-speed catalytic section from the inlet 1, and a catalytic reaction occurs on the outer surface of the plurality of catalytic elements 31, generating water vapor and releasing heat.

[0050] S2: Natural convection is formed in the chimney section.

[0051] S3: Air and water vapor flow out from the outlet 2.

[0052] After the air and water vapor flow out from the outlet, hydrogen will enter from the inlet and circulate to remove hydrogen. In the hydrogen recombiner with water-drop-shaped catalytic elements, the catalytic elements 31 are in the shape of water drops, which can reduce the flow resistance, thereby strengthening the natural convection and improving the ability of the gas flowing out from the outlet to absorb hydrogen, and improving the hydrogen removal efficiency.

[0053] Optionally, the gas flow in the catalytic channel is stable, and the flow field distribution is uniform without severe boundary layer separation phenomenon.

[0054] Optionally, the arrangement mode of the catalytic element layer 3 is stacking type or hollow type. As shown in Figure 6 , the arrangement mode of the catalytic element layer 3 is stacking type, that is, the catalytic element layer is full of catalytic elements without hollow in the middle. Figure 6 In each layer of the catalytic element layer, the plurality of catalytic elements are arranged in an m*n array. As shown in Figure 7 and Figure 8 , the arrangement mode of the catalytic element layer 3 is hollow type, that is, the catalytic elements in the catalytic element layer are only distributed on the outer layer, and the inner layer is left empty. Figure 7 and Figure 8 In each layer of the catalytic element layer, the plurality of catalytic elements are arranged in a circular array.

[0055] Optionally, the arrangement mode of the catalytic element layer 3 is regular or irregular. The number, spacing and arrangement mode of the catalytic element layer, and the number, spacing and arrangement mode of the plurality of catalytic elements in each layer of the catalytic element layer can be designed according to the actual required hydrogen removal capacity and flow resistance.

[0056] Obviously, the above disclosed embodiments of the present application are only used to help explain the present application. The embodiments do not describe all the details and do not limit the present application to the specific embodiments described. According to the content of the present specification, many modifications and changes can be made. The present specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present application, so that those skilled in the art can well understand and utilize the present application. It is not necessary and impossible to exhaust all the embodiments here. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A hydrogen recombiner using a water droplet-shaped catalytic element, characterized in that: include: A catalytic channel, wherein the catalytic channel is sequentially provided with an inlet (1), a high-speed catalytic section, a chimney section and an outlet (2); A catalytic element layer (3), the catalytic element layer (3) being arranged in the high-speed catalytic section, the catalytic element layer (3) comprising a plurality of catalytic elements (31) arranged at intervals, the catalytic elements (31) being in the shape of a water droplet; The three-dimensional streamlined solid structure of the catalytic element (31) is formed by rotating 360° based on a two-dimensional streamline with the central axis as the axis; The bottom area of ​​the drop-shaped catalyst element (31) is relatively large, and hydrogen gas first contacts the bottom of the catalyst element (31) after entering from the inlet (1).

2. The hydrogen recombiner using a water droplet-shaped catalytic element according to claim 1, characterized in that: The number of the catalytic element layers (3) is one, two or more, and the two or more catalytic element layers (3) are arranged at intervals along the extension direction of the catalytic channel.

3. The hydrogen recombiner using a water droplet-shaped catalytic element according to claim 1, characterized in that: In the catalytic element layer (3), a plurality of catalytic elements (31) are distributed in an m*n array, wherein m and n are both positive integers.

4. The hydrogen recombiner using a water droplet-shaped catalytic element according to claim 1, characterized in that: In the catalytic element layer (3), a plurality of catalytic elements (31) are distributed in a circular array.

5. A method for operating a hydrogen recombiner using a water droplet-shaped catalytic element, characterized in that: The hydrogen recombiner using the water droplet-shaped catalytic element according to any one of claims 1 to 4 is used, and the specific steps include: S1: Hydrogen and air enter the high-speed catalytic section from the inlet (1), and a catalytic reaction occurs on the outer surface of multiple catalytic elements (31), generating water vapor and releasing heat at the same time; S2: natural convection is formed in the chimney section; S3: Air and water vapor flow out from outlet (2).

6. The operating method of the hydrogen recombiner using a water droplet-shaped catalytic element according to claim 5, characterized in that: The gas flow in the catalytic channel is stable and the flow field is evenly distributed.

7. The operating method of the hydrogen recombiner using a water droplet-shaped catalytic element according to claim 5, characterized in that: Before S1, S0 is also included. S0: according to the required hydrogen removal capacity and the change of flow resistance, the number, spacing and arrangement angle and arrangement mode of the catalytic elements (31) are determined.

8. The operating method of the hydrogen recombiner using a water droplet-shaped catalytic element according to claim 7, characterized in that: The arrangement of the catalytic element layer (3) is a stacked type or a hollow type.

9. The operating method of the hydrogen recombiner using a water droplet-shaped catalytic element according to claim 7, characterized in that: The catalytic element layer (3) is arranged in a regular or irregular manner.

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