JP6034165B2 - Hydrogen removal device - Google Patents

Description

  Embodiments described herein relate generally to a hydrogen removal apparatus that removes hydrogen contained in a gas from the gas.

  In general, the containment vessel of a boiling water reactor at a boiling water nuclear power plant is equipped with a combustible gas concentration control device that suppresses the increase in the concentration of combustible gases such as hydrogen in preparation for a nuclear accident. Yes. A conventional combustible gas concentration control device installed in a reactor containment vessel of a boiling water reactor will be described with reference to FIG.

  FIG. 7 is a cross-sectional view showing a configuration of a conventional containment vessel 1 in a boiling water reactor and a conventional combustible gas concentration control device 10 applied to the boiling water reactor.

  As shown in FIG. 7, the reactor containment vessel 1 stores a reactor pressure vessel 3 containing a reactor core 2. The reactor containment vessel 1 includes an upper dry well 5, a lower dry well 6 and a wet well 7 that surround the reactor pressure vessel 3. The wet well 7 is connected to the upper dry well 5 via a vent pipe 8 to form a suppression pool 9 that holds stored water. Further, the outer surface of the reactor pressure vessel 3 is surrounded by the biological shielding wall 4.

  In the unlikely event that the reactor primary cooling system piping such as the main steam pipe 11 connected to the reactor pressure vessel 3 is broken, high temperature / high pressure reactor primary coolant is placed in the upper dry well 5 in the reactor containment vessel. The pressure and temperature of the upper dry well 5 are rapidly increased.

  The high-temperature and high-pressure coolant discharged to the upper dry well 5 is mixed with the gas in the upper dry well 5 and discharged into the stored water in the suppression pool 9 via the vent pipe 8 and cooled. The In this way, much of the thermal energy released from the reactor pressure vessel 3 is cooled and absorbed in the stored water in the suppression pool 9.

  In the reactor pressure vessel 3, the stored water in the suppression pool 9 is injected by an emergency core cooling system (not shown) to cool the core 2. The cooling water injected into the core 2 absorbs decay heat from the core 2 in the long term, and flows out to the upper dry well 5 from the fractured port of the broken pipe.

  As described above, in the unlikely event that the reactor primary cooling system pipe breaks, the pressure and temperature inside the upper dry well 5 are always higher than that of the wet well 7, and pass through the vent pipe 8. Water vapor and gas move into the wet well 7. At this time, fission products released from the core 2 and existing in the space of the upper dry well 5 are captured in the suppression pool 9 via the vent pipe 8.

  Even if the reactor primary cooling system piping does not break, if the reactor cooling function is lost due to power loss or the like, the pressure in the reactor pressure vessel 3 rises, and the safety valve 12 provided in the main steam pipe 11 In operation, water vapor and fission products in the reactor pressure vessel 3 are released into the stored water in the suppression pool 9. When the pressure of the wet well 7 becomes higher than the pressure of the dry wells 5 and 6, the vacuum break valve 13 is activated and the gas in the wet well flows into the dry well.

  Thus, under a long-term event, the coolant water is radioactively decomposed in the reactor of the light water nuclear power plant, generating hydrogen gas and oxygen gas. Further, when the temperature of the fuel cladding tube in the core 2 rises, a reaction occurs between zirconium and water vapor of the fuel cladding tube material (hereinafter referred to as “Metal-Water reaction”), and for a short time. Hydrogen gas is generated.

  The hydrogen gas generated in this manner is released into the reactor containment vessel 1 together with the coolant from the fractured opening of the broken pipe after the generation, and the concentration of hydrogen gas gradually increases inside the reactor containment vessel 1. To do. Moreover, since hydrogen gas is non-condensable, the internal pressure of the reactor containment vessel 1 also increases.

  When no effective measures can be taken against the state where hydrogen gas is generated, the hydrogen gas concentration rises to 4 vol% and the oxygen concentration rises to 5 vol% or more, that is, the combustible gas concentration exceeds the flammable limit In this case, the gas becomes flammable. Furthermore, when the hydrogen gas concentration increases, there is a possibility that an excessive reaction occurs.

  As an effective measure against the situation where the hydrogen gas concentration increases, in the case of a conventional boiling water nuclear power generation facility, the inside of the pressure-suppressed reactor containment vessel 1 is replaced with nitrogen gas to reduce the oxygen concentration. Measures are taken to keep it low. Even for hydrogen gas generated in large quantities in a short time due to the above-described Metal-Water reaction, the inside of the reactor containment vessel 1 is strictly prevented from becoming a flammable atmosphere, and inherent safety is achieved.

  In order to remove hydrogen gas, a combustible gas concentration control device 10 is provided outside the reactor containment vessel 1. The combustible gas concentration control device 10 includes a recombiner 14 and a blower 15. The combustible gas concentration control apparatus 10 sucks the atmosphere in the reactor containment vessel 1 outside the reactor containment vessel 1 and raises the temperature to increase the hydrogen gas and oxygen in the atmosphere. By recombining the gases and returning them to water, and cooling the remaining gas and returning it to the inside of the reactor containment vessel 1, the increase in the combustible gas concentration is suppressed.

  On the other hand, unlike the above-described combustible gas concentration control device 10, an external power source and drive unit are not required, and a method for statically controlling the combustible gas concentration promotes a recombination reaction using a hydrogen oxidation catalyst. There have been proposed a method of arranging a plurality of catalytic recombination apparatuses to be disposed inside the reactor containment vessel 1 and a method of heating the apparatus itself in order to promote the reaction when removing hydrogen using an active metal.

  A technique for removing hydrogen, which is such a combustible gas, is described in, for example, Japanese Patent Application Laid-Open No. 2005-3371 (Patent Document 1).

JP 2005-3371 A

  In a boiling water reactor, since the atmosphere in the reactor containment vessel in operation is replaced with nitrogen gas, oxygen that can be combined with hydrogen generated in the Metal-Water reaction is not contained in the reactor containment vessel 1. There are only a few. Under the event that a large amount of hydrogen is generated by the Metal-Water reaction, the conventional hydrogen treatment method by recombination of hydrogen and oxygen described above is a low oxygen state where there is little oxygen that can be combined with hydrogen. It is difficult to remove.

  If hydrogen cannot be removed from the atmosphere in the containment vessel, the pressure in the containment vessel cannot be reduced. In the current boiling water reactor system, when a large amount of hydrogen is generated in the containment vessel due to an accident and the pressure in the containment vessel rises, the atmosphere in the containment vessel is externalized. Although it is planned to reduce the pressure in the reactor containment vessel (to the atmosphere) to reduce the accident, the radioactive waste may be released to the outside (in the atmosphere) at the same time.

  Therefore, as a method of removing hydrogen from a gas containing hydrogen to be subjected to hydrogen removal treatment (hereinafter referred to as “treated gas”) even in a low oxygen state where oxygen concentration is low and recombination is difficult, A technique using a hydrogen storage alloy has been proposed.

  However, the weight of the hydrogen occluded by the hydrogen occlusion alloy is, for example, about 1.8% of the alloy weight in the case of Ti—Fe, and the occlusion amount is only a few percent of the alloy weight at most. Therefore, a huge amount of hydrogen storage alloy is required to cope with the situation where hydrogen is generated in large quantities, such as when a severe nuclear reactor accident occurs, using hydrogen removal technology that uses a hydrogen storage alloy. In reality, there is a problem in that it is difficult to apply.

  As another method for removing hydrogen from the gas to be treated, as described in Patent Document 1, a catalyst that promotes the hydrogen / oxygen reaction is installed in the lower stage, and a catalyst that promotes the hydrogen / nitrogen reaction is installed in the upper stage. There is also a method for removing hydrogen.

  However, within a few hours after the occurrence of a severe nuclear reactor accident, there is little oxygen in the reactor containment vessel, so there is a problem in that the hydrogen removal technology using the catalyst as a treatment material cannot always exhibit a sufficient effect.

  The embodiment of the present invention has been made in consideration of the above circumstances, and can remove hydrogen contained in the gas to be processed more smoothly even in a low oxygen state where the oxygen concentration is low and it is difficult to perform recombination. And it aims at providing the hydrogen removal apparatus which can remove hydrogen more efficiently than the case where a hydrogen storage alloy is utilized.

A hydrogen removal apparatus according to an embodiment of the present invention is a hydrogen removal apparatus for a reactor containment vessel that introduces a gas to be processed and oxidizes and removes hydrogen contained in the gas. And a hydrogen removing unit that oxidizes and removes hydrogen contained in the gas, and the hydrogen removing unit exhausts the gas from the inside, which is an opening that sucks the gas into the interior. And an exhaust part that is an opening that is disposed in a lower part of the casing, and the exhaust part is disposed in an upper part of the casing provided above and below the exhaust part. The metal oxide is a metal oxide module configured by containing a metal oxide piece in a ventable container, and the metal oxide module is oxygenated together with the metal oxide piece in the container. Reacts with and generates heat A heating element is accommodated, and the heating means includes an air supply device that supplies air or oxygen to the metal oxide module, and the heating element accommodated in the metal oxide module. It is characterized by being.

  According to the embodiment of the present invention, the removal of hydrogen contained in the gas to be processed can be started more smoothly and efficiently in a low oxygen state where oxygen concentration is low and recombination is difficult. It can be carried out.

The longitudinal cross-sectional view which shows the structure of the hydrogen removal apparatus which concerns on the 1st Embodiment of this invention. It is the schematic which shows the structure of metal peroxide module 55A-55E applied to the hydrogen removal apparatus which concerns on embodiment of this invention, (A) thru | or (E) are metal peroxide modules 55A and 55B, respectively. , 55C, 55D, 55E is a schematic diagram showing the configuration of 55E. It is the schematic which shows the structure of the metal peroxide modules 55F-55I applied to the hydrogen removal apparatus which concerns on embodiment of this invention, (A) thru | or (D) are metal peroxide modules 55F and 55G, respectively. , 55H, Schematic showing the configuration of 55I. It is sectional drawing which shows the structure of the hydrogen removal apparatus 50B which is an example of the hydrogen removal apparatus which concerns on the 2nd Embodiment of this invention, (A) is a longitudinal cross-sectional view of the whole apparatus, (B) is shown to (A). IV (B) -IV (B) sectional view (transverse sectional view). It is sectional drawing which shows the structure of the hydrogen removal apparatus 50C which is an example of the hydrogen removal apparatus which concerns on the 2nd Embodiment of this invention, (A) is a longitudinal cross-sectional view of the whole apparatus, (B) is shown to (A). V (B) -V (B) sectional view (transverse sectional view). Sectional drawing which shows the structure of the hydrogen removal apparatus which concerns on the 3rd Embodiment of this invention. Sectional drawing which shows the structure of the conventional combustible gas concentration control apparatus applied to the reactor containment vessel and boiling water reactor in a boiling water reactor.

  A hydrogen removal apparatus according to an embodiment of the present invention will be described with reference to the drawings. In the following description, words indicating directions such as up, down, left, and right are based on the illustrated state or the normal use state.

In the hydrogen removal apparatus according to the embodiment of the present invention, as a technique for removing hydrogen, a metal peroxide composed of peroxide ions (O ₂ ²⁻ ) and a metal and hydrogen contained in the gas to be processed are used. Adopting technology that consumes (removes) hydrogen by causing an oxidation reaction between them. The technology for removing hydrogen contained in the gas to be treated using the metal peroxide uses oxygen contained in the metal peroxide itself, so that hydrogen is removed from the gas to be treated without the need for external oxygen. There is an advantage that it can be removed.

  In addition, the reaction rate between the metal peroxide and hydrogen, that is, the rate of the recombination reaction in which oxygen and hydrogen separated from the metal peroxide recombine increases as a quadratic function as the temperature increases. It has been known.

  Therefore, when there is a large amount of hydrogen that needs to be removed, even if the reaction rate sufficient to treat hydrogen may not be obtained near room temperature, the treatment gas can be heated to raise the temperature. Sufficient reaction rate can be obtained. On the other hand, in order to prevent structural damage due to excessive reaction, it is also necessary to cool the gas to be treated to reduce the reaction rate.

  Considering the above-described circumstances, the hydrogen removal apparatus according to the embodiment of the present invention can safely process a large amount of hydrogen gas by controlling the temperature of the gas to be processed.

  Then, the hydrogen removal apparatus which concerns on each embodiment of this invention is demonstrated. In the following description, the hydrogen removal apparatus according to each embodiment of the present invention is installed inside the reactor containment vessel 1 (FIG. 7) and applied when removing hydrogen from the atmosphere of the reactor containment vessel 1. An example will be described.

[First embodiment]
FIG. 1 is a longitudinal sectional view showing a configuration of a hydrogen removal apparatus 50A which is an example of a hydrogen removal apparatus according to the first embodiment of the present invention, and FIGS. 2 and 3 are applied to the hydrogen removal apparatus according to the embodiment of the present invention. It is the schematic which shows the structure of metal peroxide module 55A-55E which is the Example of the metal peroxide module 55 to be performed.

  The hydrogen removal apparatus 50A includes a casing 51 in which a metal peroxide module 55 that is removed by consuming hydrogen is disposed, and a gas containing hydrogen to be subjected to hydrogen removal (hereinafter referred to as “processed gas”). The intake portion 52, which is an opening for introducing 17 into the interior of the casing 51, and the atmosphere (hereinafter referred to as "processed gas") 18 after the hydrogen removal treatment in the hydrogen removing apparatus 50A. 51 and an exhaust part 53 that is an opening for exhausting to the outside.

  In the hydrogen removal device 50 </ b> A, the intake part 52 is provided, for example, at the lower part of the casing 51, and the exhaust part 53 is provided at the upper part of the casing 51.

  When the hydrogen removal apparatus 50A is applied to a process of removing hydrogen from the atmosphere in a reactor containment vessel (not shown), the atmosphere in the reactor containment vessel 17 as the gas 17 to be treated is supplied from the intake section 52 to the casing 51. The hydrogen is removed from the gas 17 to be processed inside the casing 51 to become the processed gas 18, exhausted from the exhaust section 53 to the outside of the casing 51, and returned to the reactor containment vessel. .

  In the space inside the casing 51 of the hydrogen removing device 50A, a partition plate 54 is installed in the horizontal direction with an interval in the vertical direction. The partition plate 54 extending in the horizontal direction has one end fixed to the side wall of the casing 51 and the other end opened. Further, the end (or the open end) where the partition plate 54 is fixed to the side wall of the casing 51 is alternately arranged on the left and right when viewed from above or below.

  For example, in the four partition plates 54 arranged in the space in the casing 51 shown in FIG. 1, the one end fixed to the side wall of the casing 51 is the first and third sheets counted from above. In the partition plate 54 of the eye, it is on the right side (right end), and on the second and fourth partition plates 54 counted from above, it is on the left side (left end).

  By arranging the fixed side or the open side of the partition plate 54 alternately on the left and right sides, a space meandering left and right by the partition plate 54 is formed between the intake portion 52 and the exhaust portion 53 in the housing 51. In other words, inside the casing 51, the exhaust part 53 is finally passed through a space between one partition plate 54 and the other partition plate 54, which meanders from the intake part 52 to the left and right. A flow path to be connected is formed. The reason why the flow path is meandering is to efficiently remove (consume) hydrogen by increasing the flow path length.

  Further, in the hydrogen removal apparatus 50A, the metal peroxide module 55 is disposed between one partition plate 54 and the other partition plate 54, thereby forming a hydrogen removal unit 56 that removes hydrogen. The metal peroxide module 55 is a structure in which a metal peroxide is filled in an air permeable container.

  Further, in the hydrogen removing device 50A, for example, the gas of the hydrogen removing unit 56 is disposed in the vicinity of the gas inlet of the hydrogen removing unit 56 such as the lowermost flow path formed by the bottom and side surfaces of the housing 51 and the partition plate 54. An air supply device 57 that supplies (injects) a gas containing oxygen such as air or oxygen (hereinafter referred to as “air or the like”) to the metal peroxide module 55 disposed in the vicinity of the inlet is installed. Reference numeral 57 a denotes a nozzle (injection port) of the air supply device 57.

  Furthermore, an outer cylinder 58 is installed on the outer surface of the casing 51 so as to cover a part of the outer surface of the casing 51, and an outer wall channel 59 is formed.

  In addition, a drain pipe 61 for discharging drain such as water to the outside of the casing 51 is installed at the bottom of the casing 51.

  Next, the configuration of the metal peroxide module 55 (55A to 55I) will be described.

  For example, as shown in FIGS. 2 and 3, the metal peroxide module 55 is provided in hollow containers 63 and 66 in which holes or meshes through which gas can flow are provided in a part of the surface and the inside is formed hollow. The metal peroxide piece 64 is filled and becomes a part of the hydrogen removing unit 56 that removes hydrogen.

  Here, reference numerals 63a and 66a are porous surfaces having a size that does not allow the metal peroxide pieces 64 to flow out in a porous or mesh shape, and a gap that penetrates the surface is provided, and 63b and 66b penetrate the surface. It is a normal surface (hereinafter referred to as “non-porous surface”) in which no gap is provided.

  From the ease of constructing the hydrogen removal unit 56, the metal peroxide module 55 is a polygonal column such as a square column (cuboid) or a cylinder, such as the metal peroxide modules 55A to 55I (FIGS. 2 and 3). , Or a circular cylinder, or a solid having a shape of a part thereof (for example, a semi-cylinder).

  For example, as shown in FIG. 2A, a rectangular parallelepiped metal peroxide module 55A composed of a porous surface 63a through which the entire surface can be ventilated, or as shown in FIG. A cylindrical metal peroxide module 55 </ b> F configured with possible porous surfaces 63 a can be configured.

  Further, as shown in FIG. 2 (FIGS. 2A to 2E), metal peroxide modules 55B to 55D having different air-permeable surfaces can be configured assuming assembly.

  For example, the metal peroxide module 55B composed of the two opposing surfaces constituted by the porous surface 63a, the metal peroxide module 55C constituted of the non-permeable surface 63b where the two opposing surfaces cannot be vented, and the two adjacent surfaces Further, one surface adjacent to each of the two surfaces (three surfaces of the front surface, the bottom surface, and the right side surface in FIG. 2D) constitutes a metal peroxide module 55D composed of a non-porous surface 63b.

  If such metal peroxide modules 55A-55D are used, the hydrogen removal part 56 which has the flow path which can ventilate inside can be constructed | assembled only by arranging in multiple numbers.

  On the other hand, assuming a case where a device such as an air supply device 57 is installed inside the hydrogen removal unit 56, etc., a hollow portion that penetrates substantially the center of two opposing surfaces of the metal peroxide modules 55A to 55D in a cylindrical shape A metal peroxide module 55E provided with 65, or an annular columnar metal peroxide module 55G provided with a hollow portion 65 penetrating substantially in the center of two opposing surfaces of the metal peroxide module 55F in a cylindrical shape. Can also be configured.

  In addition, the cylindrical metal peroxide module 55F and the annular columnar metal peroxide module 55G are divided into appropriate sizes, and are a semi-columnar metal peroxide module 55H and a partial annular columnar body. The metal peroxide module 55I can also be configured.

  Further, in the hollow containers 63 and 66, a small amount of a heating element such as iron or platinum that generates heat by combining with the metal peroxide piece 64 and oxygen can be mixed. Thus, if the heating element is mixed with the metal peroxide piece 64, the gas to be ventilated can be heated by reacting with air or the like contained in the gas to be vented. In addition, the following description is an example in case a heat generating body is mixed inside the metal peroxide module 55.

  In the hydrogen removing apparatus 50A that removes hydrogen using the metal peroxide module 55 configured as described above, first, the gas 17 to be treated is introduced into the hydrogen removing apparatus 50A from the intake section 52. The gas to be treated 17 introduced into the hydrogen removal device 50 </ b> A from the intake portion 52 is guided from below the housing 51 to the hydrogen removal portion 56 in which the metal peroxide module 55 is disposed.

  On the other hand, in the vicinity of the gas inlet of the hydrogen removing unit 56, air or the like is jetted from the nozzle 57 a of the air supply device 57 to the metal peroxide module 55. The metal peroxide module 55 includes a heating element that reacts with air or the like to generate heat, and the heating target gas that reacts with air or the like injected from the nozzle 57a and flows into the hydrogen removing unit 56. 17 is heated.

  The gas to be treated 17 guided to the hydrogen removing unit 56 meanders from side to side between the metal peroxide module 55 disposed in the space partitioned by the partition plate 54, that is, between the partition plate 54 and the partition plate 54. While flowing. In the metal peroxide module 55, hydrogen contained in the gas to be processed 17 is recombined with oxygen to be consumed and removed. Since the recombination reaction is an exothermic reaction, the temperature of the gas to be processed 17 rises in the course of progress, and the reaction rate can be accelerated.

  The treated gas 18 that has been passed through the metal peroxide module 55 in sequence while meandering to the left and right to remove hydrogen and passed through the hydrogen removal unit 56 is further supplied from the exhaust unit 53 provided at the upper part of the case 51 to the case. 51 is exhausted to the outside.

  Next, a hydrogen removal method (hereinafter referred to as “first hydrogen removal method”) performed using the hydrogen removal apparatus according to the first embodiment of the present invention will be described.

  The first hydrogen removal method is performed using, for example, a hydrogen removal apparatus 50A. In the first hydrogen removal method, the hydrogen removal step of introducing the gas 17 to be treated to the hydrogen removal unit 56 including the metal peroxide module 55 in the hydrogen removal apparatus 50A and removing (consuming) hydrogen by the hydrogen removal unit 56 is performed. It has.

  In the first hydrogen removal method for removing hydrogen from the atmosphere inside the reactor containment vessel 1 using the hydrogen removal device 50A, the temperature of the fuel cladding tube rises for some reason, and water vapor and fuel cladding tube material A reaction (Metal-Water reaction) occurs with certain zirconium to generate hydrogen, which leaks from the reactor pressure vessel together with a large amount of steam. When a large amount of generated steam and hydrogen leak from the reactor pressure vessel into the reactor containment vessel, the atmosphere in the reactor containment vessel is introduced into the hydrogen removal apparatus 50A from the intake portion 52 as the gas to be treated 17. .

  At the timing immediately after the start of the Metal-Water reaction and a large amount of steam and hydrogen leaks into the reactor containment vessel, that is, at the timing when the atmosphere in the reactor containment vessel starts to flow into the hydrogen removal device 50A, Since the containment vessel is at room temperature, the gas 17 to be treated is also at room temperature.

  On the other hand, in order to make the metal peroxide react with hydrogen to consume hydrogen, it is preferable that the temperature of the gas to be treated 17 is at least 150 ° C. Therefore, in the hydrogen removal apparatus 50A, the air to be treated flows into the hydrogen removal unit 56 by reacting the heating element included in the metal peroxide module 55 with air or the like by injecting air or the like onto the metal peroxide module 55. The gas 17 is heated.

  Further, when a recombination reaction with hydrogen occurs in the first metal peroxide module 55, the gas 17 to be processed is heated by the heat generated by the recombination reaction, and the temperature rises, so that the reaction rate increases and the hydrogen removal treatment is performed. It starts smoothly.

  Thereafter, the gas 17 to be processed moves to the gas 17 to be processed while meandering in the left and right through the hydrogen removing section 56 in which a plurality of metal peroxide modules 55 are arranged in the space partitioned by the partition plate 54. The contained hydrogen is consumed and becomes water vapor. In this way, the processed gas 18 that has consumed the hydrogen contained in the gas 17 to be processed by the hydrogen removing unit 56 rises from the exhaust unit 53 provided above the housing 51 to the hydrogen removing device 50A (housing 51). It flows out and returns to the reactor containment vessel.

  During the hydrogen removal treatment, the treated gas 18 becomes a high temperature due to the reaction performed in the metal peroxide module 55, but the outside air naturally ventilates the outer wall passage 59, so that the surface of the casing 51 is air-cooled. And excessive temperature rise can be suppressed.

  According to the hydrogen removal apparatus 50A and the hydrogen removal treatment method using the hydrogen removal apparatus 50A, since the metal peroxide is used, hydrogen can be removed from the gas to be treated 17 without requiring external oxygen. That is, removal of hydrogen contained in the gas to be processed 17 can be started more smoothly even in a low oxygen state where the oxygen concentration is low and recombination reaction is unlikely to occur.

  Further, according to the hydrogen removal apparatus 50A and the hydrogen removal processing method using the hydrogen removal apparatus 50A, the gas 17 to be processed is heated in the process of flowing even when the gas 17 to be processed is sucked into the apparatus at a room temperature. Therefore, the reaction rate can be increased.

  Furthermore, according to the hydrogen removal apparatus 50A and the hydrogen removal treatment method using the hydrogen removal apparatus 50A, the outside air naturally ventilates the outer wall flow path 59, whereby the surface of the casing 51 is air-cooled, resulting in an excessive temperature rise. Can be suppressed.

  Furthermore, according to the hydrogen removal apparatus 50A and the hydrogen removal treatment method using the hydrogen removal apparatus 50A, hydrogen is consumed by the recombination reaction to remove hydrogen, so that the occlusion amount is at most about several percent of the alloy weight. Hydrogen can be removed more efficiently than when using only a hydrogen storage alloy.

  In the hydrogen removing apparatus 50A described above, a heating element that generates heat by reacting with air or the like is used as a heating means for the gas 17 to be processed. For example, a metal wire such as a nichrome wire is provided and turned on (energized). A heating means other than the heating element, such as a heater that can be switched between heating and heating stop by switching between (state) and off (non-energized state), may be further provided. The heater may be installed in the air supply device 57 or the casing 51 such as in the vicinity of the inlet to the hydrogen removing unit 56 to heat the gas to be processed 17 flowing into the hydrogen removing unit 56.

  In addition, the heater may be applied as a heating unit for the gas 17 to be processed, while a heating element may not be used. When the heater is installed in the casing 51, the air supply device 57 can be omitted. Further, the heater may be a simple metal wire such as a nichrome wire.

  Furthermore, in the hydrogen removing apparatus 50A described above, the partition plate 54 is used to secure a flow path through which the gas to be processed 17 flows, but the partition plate 54 is not necessarily used. By arranging the metal peroxide modules 55 well, the non-perforated surfaces 63b and 66b of the metal peroxide module 55 play a role in the partition plate 54, and the inside of the metal peroxide module 55 can be used without using the partition plate 54. This is because it is possible to form a flow path through which the gas 17 to be treated is vented.

[Second Embodiment]
FIG. 4 is a cross-sectional view showing a configuration of a hydrogen removal apparatus 50B which is an example of a hydrogen removal apparatus according to the second embodiment of the present invention, and FIG. 4A is a longitudinal sectional view of the entire hydrogen removal apparatus 50B. 4 (B) is a sectional view (transverse sectional view) taken along the line IV (B) -IV (B) shown in FIG. 4 (A).

  FIG. 5 is a cross-sectional view showing a configuration of a hydrogen removal apparatus 50C as an example of a hydrogen removal apparatus according to the second embodiment of the invention, and FIG. 5 (A) is a longitudinal sectional view of the entire hydrogen removal apparatus 50B. FIG. 5B is a V (B) -V (B) cross-sectional view (transverse cross-sectional view) shown in FIG.

  The hydrogen removal device 50B and the hydrogen removal device 50C differ from the hydrogen removal device 50A in the shape of the hydrogen removal unit 56, that is, in the configuration of the flow path through which the gas to be treated 17 flows. There is no difference. Therefore, in the description of the present embodiment, the difference will be mainly described, and the same components as those in the hydrogen removal apparatus 50A will be denoted by the same reference numerals and description thereof will be omitted.

  The hydrogen removing device 50B is, for example, in contact with the inner surface of the casing 51 above the intake portion 52, supports the metal peroxide module 55 disposed from the lower surface, and has a plurality of through holes that allow ventilation. The perforated support plate 68 is installed.

  In the hydrogen removing device 50B, a cylindrical hydrogen having a plurality of vertical flow paths by disposing a metal peroxide module 55 and a partition plate 54 that partitions the flow paths in the vertical direction on the upper surface of the porous support plate 68. A removal portion 56 is formed.

  In the hydrogen removing device 50B configured as described above, first, the gas 17 to be treated is introduced into the hydrogen removing device 50B from the intake portion 52. The gas to be treated 17 introduced into the hydrogen removing device 50B from the intake portion 52 passes through the porous support plate 68 from below the casing 51 and is introduced to the hydrogen removing portion 56 in which the metal peroxide module 55 is disposed. It is burned.

  On the other hand, each nozzle 57a provided in the header 57b of the air supply device 57 is arranged in the vicinity of the inlet of the vertical flow path formed in the hydrogen removing unit 56, and air or the like is provided in the metal peroxide module 55. Is injected.

  The gas to be treated 17 guided to the hydrogen removal unit 56 rises from below the metal peroxide module 55 disposed in the flow path partitioned in the vertical direction by the partition plate 54, and in the process In the oxide module 55, hydrogen contained in the gas 17 to be processed is recombined with oxygen to be consumed and removed. In the hydrogen removal apparatus 50B, the flow path of the gas to be processed 17 formed in the hydrogen removal unit 56 has a structure without bending, so that the pressure loss can be kept low.

  The treated gas 18, which is sequentially ventilated through the metal peroxide module 55 and removed from the hydrogen removal unit 56 after the removal of hydrogen, is further exhausted from the exhaust unit 53 provided at the upper part of the casing 51 to the outside of the casing 51. Is done.

  On the other hand, the hydrogen removing device 50C is, for example, in contact with the inner surface of the housing 51 above the intake portion 52, supports the metal peroxide module 55 disposed from the lower surface, and vents near the center of the housing 51. An annular support plate 69 is installed which penetrates the surface as possible.

  In the hydrogen removal device 50C, a metal peroxide module 55 and a partition plate 54 that partitions the flow path in the vertical direction are disposed on the upper surface of the annular support plate 69. The partition plate 54 is also disposed on the upper surface of the uppermost metal peroxide module 55.

  The partition plate 54 divides the flow path into a plurality of paths with respect to the circumferential direction of the hydrogen removing unit 56 and flows to the outer peripheral side without raising the gas to be processed 17 that has risen up to the uppermost stage of the metal peroxide module 55. Then, the gas 17 to be treated is guided so as to be exhausted from the side surface of the outermost metal peroxide module 55.

  In the hydrogen removing device 50C configured as described above, first, the gas 17 to be processed is introduced into the hydrogen removing device 50C from the intake portion 52. The gas to be treated 17 introduced into the hydrogen removing device 50C from the intake portion 52 passes through a through hole provided in the approximate center of the annular support plate 69 from below the housing 51 and the metal peroxide module 55 is arranged. The hydrogen removal unit 56 is provided.

  On the other hand, a nozzle 57 a of an air supply device 57 is disposed in the vicinity of the inlet of the flow path formed in the hydrogen removal unit 56, and air or the like is injected into the metal peroxide module 55. In the hydrogen removal apparatus 50C, the number of nozzles 57a can be reduced and the gas to be treated 17 can be heated more efficiently because the number of inlets to the hydrogen removal unit 56 is one.

  The gas to be processed 17 guided to the hydrogen removing unit 56 flows from the center in the circumferential direction to the outer peripheral side while rising from below the metal peroxide module 55. In the metal peroxide module 55, hydrogen contained in the gas to be processed 17 is recombined with oxygen to be consumed and removed.

  The treated gas 18, which is sequentially ventilated through the metal peroxide module 55 and removed from the hydrogen removal unit 56 after the removal of hydrogen, is further exhausted from the exhaust unit 53 provided at the upper part of the casing 51 to the outside of the casing 51. Is done.

  In addition, since the hydrogen removal method performed using the hydrogen removal apparatus according to the second embodiment of the present invention is performed in substantially the same manner as the first hydrogen removal method using the hydrogen removal apparatuses 50B and 50C, Description of the first hydrogen removal method is omitted here.

  Thus, according to the hydrogen removal processing method using the hydrogen removal devices 50B and 50C and the hydrogen removal devices 50B and 50C, the same effect as the hydrogen removal treatment method using the hydrogen removal device 50A and the hydrogen removal device 50A is obtained. be able to.

  Further, according to the hydrogen removal apparatus 50B and the hydrogen removal treatment method using the hydrogen removal apparatus 50B, the flow path of the gas to be treated 17 formed in the hydrogen removal unit 56 of the hydrogen removal apparatus 50B has a structure without bending. As a result, the pressure loss can be kept low, and the gas flow can be made smoother.

  Furthermore, according to the hydrogen removal apparatus 50C and the hydrogen removal treatment method using the hydrogen removal apparatus 50C, the number of nozzles 57a can be reduced because the number of inlets to the hydrogen removal unit 56 is one. The to-be-processed gas 17 can be heated efficiently.

[Third embodiment]
FIG. 6 is a schematic diagram showing the configuration of a hydrogen removal apparatus 50D that is an example of the hydrogen removal apparatus according to the third embodiment of the present invention.

  The hydrogen removing device 50D, for example, in contrast to the hydrogen removing device 50A, the inlet pipe 71 that guides the gas 17 to be processed from the intake portion 52 to the inside of the casing 51 and the processed gas 18 from the exhaust portion 53 to the outside of the casing 51. Although it is different in that it further includes a heat exchanger 73 that exchanges heat with the outlet pipe 72 that is exhausted to the reactor containment vessel and returned to the reactor containment vessel, there is no substantial difference in other points. Therefore, in the description of the present embodiment, the difference will be mainly described, and the same components as those in the hydrogen removal apparatus 50A will be denoted by the same reference numerals and description thereof will be omitted.

  The hydrogen removing device 50D includes a casing 51 having a metal peroxide module 55 disposed therein, an intake portion 52 for introducing the gas to be processed 17 into the casing 51, and the processed gas 18 to the outside of the casing 51. An exhaust section 53 for exhausting the exhaust gas is provided, and an inlet pipe 71 that guides the gas 17 to be processed from the intake section 52 to the inside of the casing 51 and the processed gas 18 are exhausted from the exhaust section 53 to the outside of the casing 51. A heat exchanger 73 configured to exchange heat with the outlet pipe 72 returning to the containment vessel is provided.

  The heat exchanger 73 takes heat from the processed gas 18 flowing through the outlet pipe 72 and cools the processed gas 18, and also applies heat to the processed gas 17 flowing through the inlet pipe 71 to supply the processed gas 17. Heat.

  In the hydrogen removing device 50D configured as described above, first, the processed gas 18 in which the heat exchanger 73 flows through the outlet pipe 72 before the gas to be processed 17 is introduced into the hydrogen removing device 50D from the intake portion 52. The processed gas 18 is cooled by removing heat from the gas, and the processed gas 17 is heated by applying heat to the processed gas 17 flowing through the inlet pipe 71.

  The heated gas 17 to be treated is introduced into the hydrogen removing device 50D from the intake portion 52 and guided from below the housing 51 to the hydrogen removing portion 56 in which the metal peroxide module 55 is disposed. In the hydrogen removal unit 56, the metal peroxide module 55 causes a recombination reaction with hydrogen contained in the gas 17 to be consumed and is consumed and removed. The treated gas 18 that has passed through the hydrogen removing unit 56 is further exhausted to the outside of the housing 51 from an exhaust unit 53 provided at the top of the housing 51.

  In addition, although the hydrogen removal apparatus 50D mentioned above is the structure which added the heat exchanger 73 to the hydrogen removal apparatus 50A, the hydrogen removal apparatus 50D is the structure which added the heat exchanger 73 to the hydrogen removal apparatuses 50B and 50C. But it ’s okay.

  Next, a hydrogen removal method (hereinafter, referred to as “third hydrogen removal method”) performed using the hydrogen removal apparatus according to the third embodiment of the present invention will be described.

  The third hydrogen removal method is performed using, for example, the hydrogen removal device 50D. Compared to the first hydrogen removal method, the third hydrogen removal method is performed by the heat exchanger 73 before introducing the gas 17 to be treated to the hydrogen removal unit 56. Although it is different in that it further includes a heat exchange step for heat exchange (heating) with the process gas 17, the other points are the same as in the description of the first hydrogen removal method. To do.

  In the heat exchange step, the heat exchanger 73 takes heat from the treated gas 18 flowing through the outlet pipe 72 to cool the treated gas 18, and gives heat to the gas 17 to be treated flowing through the inlet pipe 71. The processing gas 17 is heated.

  Further, in the third hydrogen removing method, when all the metal peroxide modules 55 arranged in the hydrogen removing device 50D react and the temperature of the outlet pipe 72 is heated to about 300 ° C., the air supply is performed. The apparatus 57 is stopped and the supply of air or the like to the metal peroxide module 55 is stopped. Even if the air supply device 57 is stopped, the temperature of the gas flowing into the hydrogen removal device 50D can be heated to about 200 ° C. using the heat (waste heat) of the treated gas 18, so that the hydrogen removal device 50D It is possible to proceed smoothly.

  As described above, according to the hydrogen removal processing method using the hydrogen removal apparatus 50D and the hydrogen removal apparatus 50D, it is only possible to obtain the same effect as the hydrogen removal treatment method using the hydrogen removal apparatus 50A and the hydrogen removal apparatus 50A. In addition, the temperature of the gas flowing into the hydrogen removal device 50D can be heated to a temperature sufficient for the reaction to proceed using waste heat.

  As described above, according to the hydrogen removing method performed using the hydrogen removing devices 50A to 50D and the hydrogen removing devices 50A to 50D, since the metal peroxide is used, the hydrogen is removed from the gas 17 to be processed without the need for external oxygen. Can be removed. That is, removal of hydrogen contained in the gas to be processed 17 can be started more smoothly even in a low oxygen state where the oxygen concentration is low and recombination reaction is unlikely to occur.

  In addition, according to the hydrogen removal method performed using the hydrogen removal apparatuses 50A to 50D and the hydrogen removal apparatuses 50A to 50D, even when the gas 17 to be processed is sucked into the apparatus at about room temperature, the process is performed in the flow process. Since the gas 17 is heated, the reaction rate can be increased.

  Furthermore, according to the hydrogen removal method performed using the hydrogen removal devices 50A to 50D and the hydrogen removal devices 50A to 50D, the surface of the housing 51 is air-cooled by the outside air naturally flowing through the outer wall flow path 59, and excessively Temperature rise can be suppressed.

  Furthermore, according to the hydrogen removal apparatus 50A to 50D and the hydrogen removal method performed using the hydrogen removal apparatuses 50A to 50D, hydrogen is consumed by the recombination reaction to remove the hydrogen. Hydrogen can be removed more efficiently than when a hydrogen storage alloy of only a few percent is used.

  Further, according to the hydrogen removal apparatus 50B and the hydrogen removal treatment method using the hydrogen removal apparatus 50B, the flow path of the gas to be treated 17 formed in the hydrogen removal unit 56 of the hydrogen removal apparatus 50B has a structure without bending. As a result, the pressure loss can be kept low, and the gas flow can be made smoother.

  Furthermore, according to the hydrogen removal apparatus 50C and the hydrogen removal treatment method using the hydrogen removal apparatus 50C, the number of nozzles 57a can be reduced because the number of inlets to the hydrogen removal unit 56 is one. The to-be-processed gas 17 can be heated efficiently.

  Furthermore, according to the hydrogen removal apparatus 50D and the hydrogen removal treatment method using the hydrogen removal apparatus 50D, the temperature of the gas flowing into the hydrogen removal apparatus 50D can be heated to a temperature sufficient for the reaction to proceed using waste heat. it can.

  It should be noted that the present invention is not limited to the above-described embodiment as it is, and can be implemented in various forms other than the above-described examples in the implementation stage, and various modifications can be made without departing from the spirit of the invention. Can be omitted, added, replaced, or changed. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  For example, in each embodiment, although it demonstrated as using the metal peroxide module which has a metal peroxide, it replaces with a metal peroxide and uses metal oxides, such as a copper oxide (CuO), for example. You can also. That is, a metal oxide module having a metal oxide can be used instead of the metal peroxide module.

Also in the case of using a metal oxide, O contained in the metal oxide and hydrogen gas can be combined to generate water, and hydrogen can be removed. In addition, as the metal oxide, for example, manganese peroxide (Mn _n O _m ), cobalt oxide (Co _n O _m ), or the like can be used.

  DESCRIPTION OF SYMBOLS 1 ... Reactor containment vessel, 2 ... Core, 3 ... Reactor pressure vessel, 4 ... Living body shielding wall, 5 ... Upper dry well, 6 ... Lower dry well, 7 ... Wet well, 8 ... Vent pipe, 9 ... Suppression pool DESCRIPTION OF SYMBOLS 10 ... Conventional combustible gas concentration control apparatus, 11 ... Main steam pipe, 12 ... Safety valve, 13 ... Vacuum break valve, 14 ... Recombiner, 15 ... Blower, 17 ... Processed gas, 18 ... Processed gas, 50A-50D ... Hydrogen removal device, 51 ... Case, 52 ... Intake part, 53 ... Exhaust part, 54 ... Partition plate, 55 (55A-55I) ... Metal peroxide module, 56 ... Hydrogen removal part, 57 ... Air Feeder, 57a ... nozzle, 57b ... header, 58 ... outer cylinder, 59 ... outer wall flow path, 61 ... drain pipe, 63, 66 ... hollow container, 63a, 66a ... porous surface, 63b, 66b ... non-porous surface, 64 ... metal peroxide pieces, 65 ... Empty portion, 68 ... porous support plate 69 ... annular support plate 71 ... inlet pipe, 72 ... outlet pipe, 73 ... heat exchanger.

Claims (11)

In a hydrogen removal apparatus for a reactor containment vessel that introduces a gas to be treated and oxidizes and removes hydrogen contained in the gas,
A hydrogen removing unit that causes the gas to flow and reacts the gas with a built-in metal oxide to oxidize and remove hydrogen contained in the gas;
Heating means for heating the gas before being exhausted from the hydrogen removal unit,
The hydrogen removing section includes an intake section that is an opening that sucks the gas into the inside, and an exhaust section that is an opening that exhausts the gas from the inside. The intake section is at the bottom, and the exhaust section is at the top. Is disposed inside the housing provided above the intake portion and below the exhaust portion,
The metal oxide is a metal oxide module configured by containing a metal oxide piece in a ventable container,
The metal oxide module is configured such that a heating element that reacts with oxygen together with the metal oxide piece to generate heat is contained in the container,
The said heating means is provided with the air supply apparatus which supplies air or oxygen to the said metal oxide module, and the said heat generating body accommodated in the said metal oxide module, The hydrogen removal apparatus characterized by the above-mentioned. 2. The hydrogen removing apparatus according to claim 1, wherein the heating means includes an electric heater that can be switched between heating and heating stop by switching between an energized state and a non-energized state. A partition that partitions the space between the intake portion and the exhaust portion in the housing is provided, a gas flow path through which the gas flows is formed between the partition walls, and the metal oxide is disposed in the gas flow path. The hydrogen removing apparatus according to claim 1, wherein the hydrogen removing apparatus is configured as described above. The partition wall is a partition plate disposed horizontally with an interval in the vertical direction,
4. The partition plate is arranged such that one end thereof is alternately fixed to opposite side walls of the casing and the other end is disposed in a state where a gap is provided between the side plate and the side wall. Hydrogen removal equipment. 4. The hydrogen removing apparatus according to claim 3, wherein the partition wall is arranged in a cylindrical shape having a plurality of different upper and lower diameters having the same central axis. In a hydrogen removal apparatus for a reactor containment vessel that introduces a gas to be treated and oxidizes and removes hydrogen contained in the gas,
A hydrogen removing unit that causes the gas to flow and reacts the gas with a built-in metal oxide to oxidize and remove hydrogen contained in the gas;
Heating means for heating the gas before being exhausted from the hydrogen removal unit,
The hydrogen removing section includes an intake section that is an opening that sucks the gas into the inside, and an exhaust section that is an opening that exhausts the gas from the inside. The intake section is at the bottom, and the exhaust section is at the top. Is disposed inside the housing provided above the intake portion and below the exhaust portion,
A partition that partitions the space between the intake portion and the exhaust portion in the housing is provided, a gas flow path through which the gas flows is formed between the partition walls, and the metal oxide is disposed in the gas flow path. Is configured,
The partition wall is arranged in a cylindrical shape with a plurality of different diameters having the same central axis, and the upper surface of the cylindrical partition wall arranged in the cylindrical shape is closed with a disc, and the lower surface is the central part A hydrogen removing apparatus, wherein the cylindrical partition wall is formed in a porous shape or a mesh shape. The hydrogen removing apparatus according to claim 6, wherein the heating unit includes an electric heater that can switch between heating and heating stop by switching between an energized state and a non-energized state. The hydrogen removal apparatus according to claim 6 or 7, wherein the metal oxide is a metal oxide module configured such that a metal oxide piece is accommodated in a ventable container. The hydrogen removing apparatus according to claim 3, wherein the partition wall is a non-porous surface of the metal oxide module. 10. An outer cylinder is further installed on the outer surface of the casing so as to cover a part of the outer surface, and ventilation is possible between the casing and the outer cylinder. The hydrogen removing apparatus according to any one of the above. 2. The heat exchanger according to claim 1, further comprising a heat exchanger for exchanging heat between heat of an inlet pipe that guides the gas to the intake part and heat of an outlet pipe through which the gas exhausted from the exhaust part is vented. The hydrogen removing apparatus according to any one of 10.

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