JP7614970B2 - Hydrogen treatment device and method - Google Patents

Description

Embodiments of the present invention relate to a hydrogen treatment device and a hydrogen treatment method for disposing of hydrogen contained in a gas.

In the event of a severe accident, the hot zirconium in the fuel cladding reacts with water (metal-water reaction) inside the reactor containment vessel, generating large amounts of hydrogen. If the amount of hydrogen contained is 4 vol% or more, there is a risk of a hydrogen explosion, so it is difficult to burn the hydrogen by directly introducing oxygen-containing air into the reactor containment vessel, or to promote the reaction between hydrogen and oxygen using a catalyst. In particular, in boiling water reactors, the reactor containment vessel is filled with nitrogen, and there is almost no oxygen in the atmosphere, so other measures are necessary.

In systems where it is difficult to introduce oxygen, a method of treating hydrogen using metal oxides can be considered. Hydrogen can be treated by reacting hydrogen with oxygen from a metal oxide to produce water. In systems where oxygen cannot be introduced, such as glove boxes, hydrogen is similarly treated by introducing hydrogen into metal oxide. Characteristics of the gas composition during a severe accident include the almost complete absence of oxygen, as well as high concentrations of hydrogen and water vapor. The above-mentioned metal oxides that are filled into hydrogen treatment equipment for nuclear power plants are used in the form of powder or compacts.

JP 2015-187553 A JP 2016-8839 A

Metal oxides, which generate a large amount of heat of reaction, have the advantage that the heat of reaction increases the temperature, increasing the processing speed, and that the reaction is less susceptible to inhibition by water vapor. However, when processing high concentrations of hydrogen, the large heat of reaction causes a large increase in temperature in the reactor, and at high temperatures, there is a possibility that the hydrogen will exceed its spontaneous ignition temperature and react with the oxygen present in the reactor containment vessel, or that the decomposition temperature of the metal oxide will be reached, resulting in the release of oxygen.

In Patent Document 1, a low-heat treating material is placed upstream with a determined amount and length in order to warm the treating gas, and the heated treating gas is then circulated through the high-heat treating material to treat hydrogen. However, with this method, when a treating gas containing high concentration hydrogen is introduced, there is a risk that the high-heat treating material will exceed the hydrogen spontaneous combustion temperature of 500°C, which requires limiting the amount of hydrogen supply and installing additional cooling equipment, resulting in increased treating time and equipment costs.

On the other hand, when using only metal oxides that generate a small amount of heat of reaction, the above-mentioned constraints do not exist. However, there are concerns that the reaction will not increase the temperature to increase the processing speed, that the processing speed of low-concentration hydrogen gas will further decrease because the temperature does not increase, and that the reaction will be significantly inhibited by water vapor. These become issues when it is desired to shorten the processing time.

The embodiment of the present invention has been made in consideration of the above circumstances, and aims to provide a hydrogen treatment device and a hydrogen treatment method that can suppress the temperature rise of the treatment material and shorten the hydrogen treatment time.

A hydrogen treatment device in an embodiment of the present invention is characterized in that it comprises treatment materials each composed of two or more types of metal oxides having different reaction heats, and these treatment materials are mixed and filled into a single reactor, and within the reactor, the treatment material made of a low-heat-generating metal oxide having a small reaction heat is arranged on the upstream side, and the treatment material made of a high-heat-generating metal oxide having a large reaction heat is arranged on the downstream side, and the low-heat-generating metal oxide among the metal oxides having a small reaction heat is configured to treat hydrogen with high-concentration hydrogen gas.

A hydrogen processing method in an embodiment of the present invention is characterized in that a treatment material composed of two or more types of metal oxides each having a different heat of reaction is mixed and filled into one reactor, and the reactor is used in which the treatment material made of a low-heat-producing metal oxide having a small heat of reaction is arranged upstream and the treatment material made of a high-heat-producing metal oxide having a large heat of reaction is arranged downstream , and the low-heat-producing metal oxide having a small heat of reaction among the metal oxides is used to treat hydrogen with high-concentration hydrogen gas.

According to an embodiment of the present invention, it is possible to suppress the temperature rise of the treatment material and shorten the hydrogen treatment time.

1 is a schematic diagram showing the configuration of a hydrogen treatment device according to a first embodiment. FIG. 4 is a schematic diagram showing the configuration of a hydrogen treatment device according to a second embodiment. FIG. 11 is a schematic diagram showing the configuration of a hydrogen treatment device according to a third embodiment. FIG. 13 is a schematic diagram showing the configuration of a hydrogen treatment device according to a fourth embodiment. FIG. 5 is a schematic diagram showing a configuration of a modified example of the hydrotreating device in FIG. 4 . FIG. 13 is a schematic diagram showing the configuration of a hydrogen treatment device according to a fifth embodiment. FIG. 13 is a schematic diagram showing the configuration of a hydrogen treatment apparatus according to a sixth embodiment when hydrogen concentration is high. FIG. 8 is a schematic diagram showing the configuration of the hydrogen treatment device in FIG. 7 when the hydrogen concentration is low. FIG. 13 is a schematic diagram showing the configuration of a hydrogen treatment apparatus according to a seventh embodiment when hydrogen concentration is high. FIG. 10 is a schematic diagram showing the configuration of the hydrogen treatment device in FIG. 9 when the hydrogen concentration is low.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[A] First embodiment (FIG. 1)
Fig. 1 is a schematic diagram showing the configuration of a hydrogen treatment device according to the first embodiment. The hydrogen treatment device 10 shown in Fig. 1 oxidizes hydrogen generated in a reactor containment vessel 1 during a severe accident of a nuclear reactor, converting it into water (including water vapor) to reduce the hydrogen concentration, and includes a reactor 12 filled with a treatment material 11, a blower 13, a heater 14, a cooler 15, a drain tank 16, an upstream on-off valve 17, and a downstream on-off valve 18.

The treatment material 11 oxidizes hydrogen in a hydrogen-containing gas and converts it into water (including water vapor). This treatment material 11 is made by mixing two or more types of metal oxides with different reaction heats, for example, a low-heat-producing metal oxide with a small reaction heat and a high-heat-producing metal oxide with a large reaction heat, in a powder state and molding them into a single treatment material, and multiple pieces are filled into the reactor 12.

Here, examples of low heat generating metal _oxides include _Co3O4 , CoO, NiO, _Mn3O4 , _etc. Examples of high heat generating metal oxides include CuO, _{MnO2 , Mn2O3} , _MoO3 , _{Cr2O3 , etc.} The low heat generating metal oxide may be two or more of _Co3O4 , CoO, etc. Similarly, the high heat generating metal oxide may be two or more of CuO, MnO2, _etc. Furthermore, when mixing and molding the low heat generating metal oxide and the high heat generating metal oxide, a binder such as silica or hydraulic alumina may be used.

There is no particular limit to the amount of high heat generating metal oxide added, but from the viewpoint of suppressing heat generation, it is preferable to set the upper limit at approximately the same weight ratio (50 wt%) as the low heat generating metal oxide. More preferably, the amount of high heat generating metal oxide is adjusted so that the total reaction heat of the low heat generating metal oxide and the total reaction heat of the high heat generating metal oxide are equal. This results in a greater amount of low heat generating metal oxide than the high heat generating metal oxide, and also suppresses the total reaction heat of the treatment material 11 to approximately twice that of the low heat generating metal oxide alone, making it possible to suppress heat generation.

The blower 13 starts up when the upstream on-off valve 17 and downstream on-off valve 18 are opened, and guides the hydrogen-containing gas in the reactor containment vessel 1 to the reactor 12. The heater 14 heats the hydrogen-containing gas and adjusts the temperature of the gas, the treatment material 11, and the reactor 12 to a temperature at which the two metal oxides react. The cooler 15 cools the gas in the reactor 12, in which the hydrogen has been treated by the treatment material 11 and the hydrogen concentration has been reduced. The gas cooled by the cooler 15 is returned to the reactor containment vessel 1 via the downstream on-off valve 18. The water (including water vapor) in the gas cooled by the cooler 15 is discharged to the drain tank 16, but may be returned to the reactor containment vessel 1 together with the gas.

If hydrogen is generated inside the reactor containment vessel 1 during a severe accident, the upstream on-off valve 17 and downstream on-off valve 18 are opened, and the gas containing hydrogen inside the reactor containment vessel 1 is circulated to the reactor 12 filled with the treatment material 11 using a blower 13 or the like. The hydrogen gas, treatment material 11, and reactor 12 are heated by a heater 14 to a temperature at which the two metal oxides react, and the hydrogen is treated by reacting with the two metal oxides to generate water (water vapor).

The treated gas is cooled in the cooler 15 and then returned to the reactor containment vessel 1, thereby reducing the hydrogen concentration in the reactor containment vessel 1. In addition, the water generated by the cooling in the cooler 15 is separated and discharged to the drain tank 16. The water generated by the cooler 15 may be returned to the reactor containment vessel 1.

As configured as above, the first embodiment provides the following advantages (1) to (4).
(1) The treatment material 11 is formed by mixing low heat generating metal oxide and high heat generating metal oxide, and furthermore, the amount of high heat generating metal oxide is small, and the majority is low heat generating metal oxide. Therefore, the low heat generating metal oxide treats hydrogen from the high concentration hydrogen gas introduced into the reactor 12, so that it is possible to suppress the temperature rise of the hydrogen gas, the treatment material 11, and the reactor 12. In addition, because hydrogen is highly concentrated, hydrogen can be quickly treated in a short time.

(2) Since the treatment material 11 is formed by mixing low heat generating metal oxide and high heat generating metal oxide, the high heat generating metal oxide can quickly treat hydrogen in a short time for low concentration hydrogen gas with a low hydrogen concentration introduced into the reactor 12. In addition, since the treatment material 11 contains a small amount of high heat generating metal oxide and is mostly low heat generating metal oxide, it is possible to suppress the temperature rise of the hydrogen gas, the treatment material 11, and the reactor 12 when treating low concentration hydrogen gas with the high heat generating metal oxide. In addition, in the case of low concentration hydrogen gas, since not much metal oxide is required for hydrogen treatment, hydrogen can be sufficiently treated even with a small amount of high heat generating metal oxide.

(3) The treatment material 11 is formed by mixing low heat generating metal oxide and high heat generating metal oxide, and the reaction activity of the low heat generating metal oxide is increased by the reaction heat generated by the high heat generating metal oxide. This makes it possible to improve the treatment speed of high concentration hydrogen gas by the low heat generating metal oxide.

(4) Whether high-concentration hydrogen gas is treated with low-heat-generating metal oxides or low-concentration hydrogen gas is treated with high-heat-generating metal oxides, the temperature rise of the hydrogen gas, treatment material 11, and reactor 12 is suppressed as described above in (1) and (2). This eliminates the need for a cooling device to cool the treatment material 11, etc., thereby reducing equipment costs.

[B] Second embodiment (FIG. 2)
2 is a schematic diagram showing the configuration of a hydrogen treatment device according to a second embodiment. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof will be simplified or omitted.

The hydrogen treatment device 20 of the second embodiment differs from the first embodiment in that two or more types of metal oxides with different reaction heats, for example, a treatment material 21 formed from a low-heat-producing metal oxide with a small reaction heat and a treatment material 22 formed from a high-heat-producing metal oxide with a large reaction heat, are evenly dispersed, mixed, and filled in one reactor 12.

Here, examples of low heat generating metal _oxides include _Co3O4 , CoO, NiO, _Mn3O4 , _etc. Examples of high heat generating metal oxides include CuO, _{MnO2 , Mn2O3 , MoO3 , Cr2O3} , _etc. Two or more types of low heat generating metal oxides such as _Co3O4 and CoO may be used. Similarly, two or more types of high heat generating metal oxides such as CuO and _MnO2 may be used.

The mixing ratio of the low heat generating metal oxide treatment material 21 and the high heat generating metal oxide treatment material 22 in the reactor 12 is preferably set to 50 wt % or less by weight in the reactor 12 from the viewpoint of suppressing heat generation. It is preferable to adjust the amounts of the treatment materials 21 and 22 in the reactor 12 so that the total reaction heat amount of the low heat generating metal oxide treatment material 21 and the total reaction heat amount of the high heat generating metal oxide treatment material 22 are equal. Therefore, a greater amount of treatment material 21 than treatment material 22 is placed in the reactor 12.

If hydrogen is generated inside the reactor containment vessel 1 during a severe accident, the upstream on-off valve 17 and downstream on-off valve 18 are opened, and the gas containing hydrogen inside the reactor containment vessel 1 is circulated to the reactor 12 filled with treatment materials 21 and 22 using a blower 13 or the like. The hydrogen gas, treatment materials 21, 22, and reactor 12 are heated by a heater 14 to a temperature at which the two metal oxides react, and the hydrogen is treated by reacting with the two metal oxides to generate water (water vapor).

The treated gas is cooled in the cooler 15 and then returned to the reactor containment vessel 1, thereby reducing the hydrogen concentration in the reactor containment vessel 1. In addition, the water generated by the cooling in the cooler 15 is separated and discharged to the drain tank 16. The water generated by the cooler 15 may be returned to the reactor containment vessel 1.

As configured above, the second embodiment provides the same effect as effect (4) of the first embodiment, as well as the following effects (5) and (6).

(5) A larger amount of the treatment material 21 made of low heat generating metal oxide is placed in the reactor 12 than the treatment material 22 made of high heat generating metal oxide, and this treatment material 21 treats the high concentration hydrogen gas introduced into the reactor 12. At this time, since the treatment material 21 is made of low heat generating metal oxide, it is possible to suppress the temperature rise of the hydrogen gas, the treatment materials 21, 22, and the reactor 12. In addition, since hydrogen is highly concentrated, the treatment material 21 can quickly treat the hydrogen in a short period of time.

(6) The reactor 12 is filled with a treatment material 21 made of a low heat generating metal oxide and a treatment material 22 made of a high heat generating metal oxide, and the treatment material 22 can quickly treat the low concentration hydrogen gas introduced into the reactor 12 in a short time. At this time, since the hydrogen is low in concentration and the amount of the treatment material 22 is smaller than that of the treatment material 21, the temperature rise of the hydrogen gas, the treatment materials 21, 22, and the reactor 12 can be suppressed. In addition, in the case of low concentration hydrogen gas, since not much metal oxide is required to treat the hydrogen, even if the amount of the treatment material 22 made of a high heat generating metal oxide is small, the hydrogen can be sufficiently treated.

[C] Third embodiment (FIG. 3)
3 is a schematic diagram showing the configuration of a hydrogen treatment device according to a third embodiment. In the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof will be simplified or omitted.

The hydrogen treatment device 30 of the third embodiment differs from the second embodiment in that a treatment material 21 made of a low heat generating metal oxide with a small reaction heat is accommodated on the upstream side of the reactor 12, and a treatment material 22 made of a high heat generating metal oxide with a large reaction heat is accommodated and packed on the downstream side of the reactor 12.

However, the layer height and amount of the low heat generating metal oxide treatment material 21 and the high heat generating metal oxide treatment material 22 are appropriately designed so that the temperature of the treatment materials 21, 22 and the reactor 12 does not rise. For example, the amount of the high heat generating metal oxide treatment material 22 suppresses heat generation by making the total reaction heat of the treatment material 22 equal to or less than the total reaction heat of the low heat generating metal oxide treatment material 21. Therefore, a larger amount of treatment material 21 than treatment material 22 is accommodated in the reactor 12.

If hydrogen is generated inside the reactor containment vessel 1 during a severe accident, the upstream on-off valve 17 and downstream on-off valve 18 are opened, and the gas containing hydrogen inside the reactor containment vessel 1 is circulated to the reactor 12 filled with treatment materials 21 and 22 using a blower 13 or the like. The hydrogen gas, treatment materials 21, 22, and reactor 12 are heated by a heater 14 to a temperature at which the two metal oxides react, and the hydrogen is treated by reacting with the two metal oxides to generate water (water vapor).

The treated gas is cooled in the cooler 15 and then returned to the reactor containment vessel 1, thereby reducing the hydrogen concentration in the reactor containment vessel 1. In addition, the water generated by the cooling in the cooler 15 is separated and discharged to the drain tank 16. The water generated by the cooler 15 may be returned to the reactor containment vessel 1.

As configured above, the third embodiment provides the same effect as effect (4) of the first embodiment, as well as the following effects (7) and (8).

(7) A larger amount of low heat generating metal oxide treatment material 21 is accommodated upstream of the reactor 12 than the high heat generating metal oxide treatment material 22 accommodated downstream. Therefore, even though the treatment material 21 has low activity, it can quickly treat hydrogen in a short time because it has a high hydrogen concentration relative to the high concentration hydrogen gas introduced into the reactor 12. At this time, because the heat value of the low heat generating metal oxide of the treatment material 21 is low, it is possible to suppress the temperature rise of the hydrogen gas, the treatment materials 21, 22, and the reactor 12.

(8) When hydrogen gas becomes low-concentration hydrogen in the reactor 12 and the processing speed is reduced in the low-heat-generating metal oxide processing material 21, or when low-concentration hydrogen gas is introduced into the reactor 12, the high-heat-generating metal oxide processing material 22 downstream of the reactor 12 can quickly process the hydrogen in a short time. At this time, the high-heat-generating metal oxide of the processing material 22 reacts with low-concentration hydrogen to generate a low amount of heat, so that the temperature rise of the hydrogen gas, the processing materials 21, 22, and the reactor 12 can be suppressed.

[D] Fourth embodiment (FIGS. 4 and 5)
4 is a schematic diagram showing the configuration of a hydrogen treatment device according to a fourth embodiment. In the fourth embodiment, the same components as those in the first and second embodiments are denoted by the same reference numerals as those in the first and second embodiments, and the description thereof will be simplified or omitted.

The hydrogen treatment device 40 of the fourth embodiment differs from the second and third embodiments in that the treatment material 21 formed from a low heat generating metal oxide with a small reaction heat and the treatment material 22 formed from a high heat generating metal oxide with a large reaction heat are filled in the reactor 12 with the arrangement ratio gradually changing from the upstream side to the downstream side of the reactor 12. In other words, the arrangement ratio of the treatment material 21 of the low heat generating metal oxide and the treatment material 22 of the high heat generating metal oxide in the reactor 12 is such that the treatment material 21 is high on the upstream side of the reactor 12 and the treatment material 22 gradually increases toward the downstream side of the reactor 12.

However, the layer height and capacity of the low heat generating metal oxide treatment material 21 and the high heat generating metal oxide treatment material 22 are appropriately designed so that the temperature of the treatment materials 21, 22 and the reactor 12 does not rise. For example, the amount of high heat generating metal oxide treatment material 22 is controlled by making the total reaction heat of the treatment material 22 equal to or less than the total reaction heat of the low heat generating metal oxide treatment material 21, thereby suppressing heat generation. As a result, a greater amount of treatment material 21 than treatment material 22 is placed in the reactor 12.

In addition, when the arrangement ratio of the treatment material 21 and the treatment material 22 in the reactor 12 is gradually changed from the upstream side to the downstream side of the reactor 12, the treatment materials 21 and 22 may be accommodated and filled in the reactor 12 with a gradation as shown in Figure 5 applied to the boundary between the treatment material 21 and the treatment material 22.

If hydrogen is generated inside the reactor containment vessel 1 during a severe accident, the upstream on-off valve 17 and downstream on-off valve 18 are opened, and the gas containing hydrogen inside the reactor containment vessel 1 is circulated to the reactor 12 filled with treatment materials 21 and 22 using a blower 13 or the like. The hydrogen gas, treatment materials 21, 22, and reactor 12 are heated by a heater 14 to a temperature at which the two metal oxides react, and the hydrogen is treated by reacting with the two metal oxides to generate water (water vapor).

The treated gas is cooled in the cooler 15 and then returned to the reactor containment vessel 1, thereby reducing the hydrogen concentration in the reactor containment vessel 1. In addition, the water generated by the cooling in the cooler 15 is separated and discharged to the drain tank 16. The water generated by the cooler 15 may be returned to the reactor containment vessel 1.

As configured as described above, the fourth embodiment provides the same effects as the effect (4) of the first embodiment and the effects (7) and (8) of the third embodiment, as well as the following effect (9).

(9) The low heat generating metal oxide treatment material 21 and the high heat generating metal oxide treatment material 22 are filled in the reactor 12 with the treatment material 21 being placed more on the upstream side and the treatment material 22 being gradually increased from the upstream side to the downstream side, with the ratio of the treatment material 21 to the treatment material 22 being changed. Therefore, when the low heat generating metal oxide of the treatment material 21 treats hydrogen from high concentration hydrogen gas, the activity of the low heat generating metal oxide is increased by the reaction heat of the high heat generating metal oxide of the treatment material 22, so that the hydrogen treatment of high concentration hydrogen gas by the treatment material 21 of the low heat generating metal oxide can be carried out more quickly in a short time.

[E] Fifth embodiment (FIG. 6)
6 is a schematic diagram showing the configuration of a hydrogen treatment device according to a fifth embodiment. In the fifth embodiment, the same components as those in the first and second embodiments are denoted by the same reference numerals as those in the first and second embodiments, and the description thereof will be simplified or omitted.

The hydrogen treatment device 50 of the fifth embodiment differs from the second to fourth embodiments in that a first reactor 51 is filled with a treatment material 21 formed from a low heat generating metal oxide with a small reaction heat, a second reactor 52 is filled with a treatment material 22 formed from a high heat generating metal oxide with a large reaction heat, and the first reactor 51 is connected in series to the front stage of the second reactor 52 (i.e., the upstream side of the hydrogen gas flow).

However, in order to prevent a temperature rise in the treatment material 22 and the second reactor 52, the first reactor 51 is filled with a treatment material 21 of low heat generating metal oxide in an amount capable of treating high concentration hydrogen gas to low concentration hydrogen gas, thereby preventing untreated high concentration hydrogen gas by the treatment material 21 from being introduced into the second reactor 52. In addition, since the reaction activity of the high heat generating metal oxide of the treatment material 22 is higher than that of the low heat generating metal oxide of the treatment material 21, it is not necessary to increase the temperature of the hydrogen gas to be introduced into the second reactor 52. Furthermore, in order to suppress the temperatures of the treatment material 22 and the second reactor 52, it is desirable to set the temperature of the treatment material 22 of high heat generating metal oxide to a lower temperature than that of the treatment material 21 of low heat generating metal oxide. For this purpose, it is preferable to provide a means for lowering the heating temperature of the second reactor 52 or increasing heat dissipation.

If hydrogen is generated in the reactor containment vessel 1 during a severe accident, the upstream on-off valve 17 and downstream on-off valve 18 are opened, and the gas containing hydrogen in the reactor containment vessel 1 is sequentially circulated using a blower 13 or the like to the first reactor 51 and the second reactor 52, which are filled with the treatment materials 21 and 22, respectively. The hydrogen gas, the treatment material 21, and the first reactor 51 are heated by the heater 14 to a temperature at which the low heat generating metal oxide reacts, and the hydrogen is reacted with the treatment material 21 in the first reactor 51, and further reacted with the treatment material 22 in the second reactor 52 to generate water (water vapor), thereby treating the hydrogen.

The treated gas is cooled in the cooler 15 and then returned to the reactor containment vessel 1, thereby reducing the hydrogen concentration in the reactor containment vessel 1. In addition, the water generated by the cooling in the cooler 15 is separated and discharged to the drain tank 16. The water generated by the cooler 15 may be returned to the reactor containment vessel 1.

As configured above, the fifth embodiment provides the same effect as effect (4) of the first embodiment, as well as the following effects (10) and (11).

(10) The first reactor 51 on the upstream side is filled with a treatment material 21 made of a low heat generating metal oxide, and the second reactor 52 on the downstream side is filled with a treatment material 22 made of a high heat generating metal oxide. Therefore, even if the treatment material 21 has low activity, it can quickly treat hydrogen in a short time because it has a high hydrogen concentration relative to the high concentration hydrogen gas introduced into the first reactor 51. At this time, since the heat value of the low heat generating metal oxide of the treatment material 21 in the first reactor 51 is low, the temperature rise of the hydrogen gas, the treatment material 21, and the first reactor 51 can be suppressed.

(11) When hydrogen gas becomes low-concentration hydrogen gas in the first reactor 51 and the processing speed is reduced in the low-heat-generating metal oxide processing material 21, or when low-concentration hydrogen gas is introduced into the first reactor 51, the high-heat-generating metal oxide processing material 22 in the second reactor 52 can quickly process the hydrogen in a short time. At this time, the high-heat-generating metal oxide of the processing material 22 in the second reactor 52 reacts with low-concentration hydrogen and generates a low amount of heat, so that the temperature rise of the hydrogen gas, the processing materials 21, 22, the first reactor 51, and the second reactor 52 can be suppressed.

[F] Sixth embodiment (FIGS. 7 and 8)
7 is a schematic diagram showing the configuration of a hydrogen treatment apparatus according to the sixth embodiment when the hydrogen concentration is high. In the sixth embodiment, the same parts as those in the first, second and fifth embodiments are denoted by the same reference numerals as those in the first, second and sixth embodiments, and the description thereof will be simplified or omitted.

The hydrogen treatment device 60 of the sixth embodiment differs from the fifth embodiment in that it is provided with a return pipe 64 in which a first switching valve 61 is disposed downstream of the first reactor 51 and connected to the cooler 15, and further includes a second switching valve 62 in the connecting pipe between the first reactor 51 and the second reactor 52, and a third switching valve 63 in the connecting pipe between the second reactor 52 and the cooler 15, so that hydrogen gas is selectively circulated through the first reactor 51, the first reactor 51 and the second reactor 52.

When hydrogen is generated in the reactor containment vessel 1 during a severe accident and a high concentration of hydrogen gas is measured by the hydrogen concentration meter 65, as shown in FIG. 7, the second changeover valve 62 and the third changeover valve 63 are closed, and the upstream opening/closing valve 17, the downstream opening/closing valve 18, and the first changeover valve 61 are opened, and the gas containing hydrogen in the reactor containment vessel 1 is circulated to the first reactor 51 filled with the treatment material 21 using the blower 13 or the like. The hydrogen gas, the treatment material 21, and the first reactor 51 are heated by the heater 14 to a temperature at which the low heat generating metal oxide reacts, and the treatment material 21 in the first reactor 51 reacts with the hydrogen to generate water (water vapor), thereby treating the hydrogen.

When the hydrogen-containing gas generated in the reactor containment vessel 1 during a severe accident is measured as low-concentration hydrogen gas by the hydrogen concentration meter 65, as shown in FIG. 8, the first switching valve 61 is closed, and the upstream opening/closing valve 17, the downstream opening/closing valve 18, the second switching valve 62, and the third switching valve 63 are opened, and the hydrogen-containing gas in the reactor containment vessel 1 is circulated to the first reactor 51 filled with the treatment material 21 and the second reactor 52 filled with the treatment material 22 using the blower 13 or the like. With low-concentration hydrogen gas, the treatment material 21 in the first reactor 51 is low in activity and hardly reacts, while the treatment material 22 of the high heat generating metal oxide in the second reactor 52 reacts with hydrogen to generate water (water vapor), thereby treating the hydrogen. In addition, the heater 14 adjusts the temperature of the low-concentration hydrogen gas flowing into the first reactor 51 and the second reactor 52 if necessary.

The treated gas is cooled in the cooler 15 and then returned to the reactor containment vessel 1, thereby reducing the hydrogen concentration in the reactor containment vessel 1. In addition, the water generated by the cooling in the cooler 15 is separated and discharged to the drain tank 16. The water generated by the cooler 15 may be returned to the reactor containment vessel 1.

As configured above, the sixth embodiment provides the same effect as effect (4) of the first embodiment, as well as the following effects (12) and (13).

(12) When the hydrogen gas from the reactor containment vessel 1 is measured as high-concentration hydrogen gas by the hydrogen concentration meter 65, this hydrogen gas is introduced only into the first reactor 51 filled with the treatment material 21, as shown in FIG. 7. Therefore, even if the treatment material 21 made of low-heat-generating metal oxide has low activity, it can quickly treat hydrogen in a short time because it has a high hydrogen concentration compared to the high-concentration hydrogen gas introduced into the first reactor 51. At this time, since the heat value of the low-heat-generating metal oxide of the treatment material 21 in the first reactor 51 is low, the temperature rise of the hydrogen gas, the treatment material 21, and the first reactor 51 can be suppressed.

(13) When the hydrogen gas from the containment vessel 1 becomes low-concentration hydrogen gas as a result of the processing by the processing material 21 in the first reactor 51 and is measured by the hydrogen concentration meter 65, or when the hydrogen gas from the containment vessel 1 is measured by the hydrogen concentration meter 65 as being low-concentration hydrogen gas, the hydrogen gas is introduced into the first reactor 51 and the second reactor 52 as shown in FIG. 8. In this case, the processing material 22 of the high heat generating metal oxide in the second reactor 52 can quickly process the hydrogen from the low-concentration hydrogen gas in a short time. At this time, the high heat generating metal oxide of the processing material 22 in the second reactor 52 reacts with the low-concentration hydrogen to generate a low amount of heat, so that the temperature rise of the hydrogen gas, the processing materials 21, 22, the first reactor 51, and the second reactor 52 can be suppressed.

[G] Seventh embodiment (FIGS. 9 and 10)
9 is a schematic diagram showing the configuration of a hydrogen treatment apparatus according to the seventh embodiment when the hydrogen concentration is high. In the seventh embodiment, the same parts as those in the first, second and fifth embodiments are denoted by the same reference numerals as those in the first, second and fifth embodiments, and the description thereof will be simplified or omitted.

The seventh embodiment of the hydrogen treatment device 70 differs from the fifth embodiment in that the hydrogen gas is introduced into the first reactor 51, which is filled with a treatment material 21 of a low heat generating metal oxide that generates a small amount of reaction heat, and the second reactor 52, which is filled with a treatment material 22 of a high heat generating metal oxide that generates a large amount of reaction heat, in a switched manner depending on the hydrogen concentration of the hydrogen gas.

In other words, between the heater 14 and the cooler 15, a first low heat generation side switching valve 71, a first reactor 51, and a second low heat generation side switching valve 72 are connected in series, and a first high heat generation side switching valve 73, a second reactor 52, and a second high heat generation side switching valve 74 are connected in series, and are arranged in parallel, so that hydrogen gas is selectively introduced into the first reactor 51 or the second reactor 52 depending on the hydrogen concentration of the hydrogen gas measured by the hydrogen concentration meter 65.

When hydrogen is generated in the reactor containment vessel 1 during a severe accident, and the hydrogen concentration meter 65 measures that the hydrogen gas has a high concentration equal to or greater than a predetermined value, as shown in FIG. 9, the high heat-generating side first switching valve 73 and the high heat-generating side second switching valve 74 are closed, and the low heat-generating side first switching valve 71 and the low heat-generating side second switching valve 72 are opened, and the gas containing hydrogen in the reactor containment vessel 1 is circulated to the first reactor 51 filled with the treatment material 21 using a blower 13 or the like. The hydrogen gas, the treatment material 21, and the first reactor 51 are heated by the heater 14 to a temperature at which the low heat-generating metal oxide reacts, and the treatment material 21 in the first reactor 51 reacts with the hydrogen to generate water (water vapor), thereby treating the hydrogen.

When the hydrogen-containing gas generated in the reactor containment vessel 1 during a severe accident is measured by the hydrogen concentration meter 65 as low-concentration hydrogen gas below a predetermined value, the low-heat-side first switching valve 71 and the low-heat-side second switching valve 72 are closed, and the high-heat-side first switching valve 73 and the high-heat-side second switching valve 74 are opened, as shown in FIG. 10, and the hydrogen-containing gas in the reactor containment vessel 1 is circulated to the second reactor 52 filled with the treatment material 22 using a blower 13 or the like. In the case of low-concentration hydrogen gas, the treatment material 22 of the high-heat-generating metal oxide in the second reactor 52 reacts with hydrogen to generate water (water vapor), thereby treating the hydrogen. In addition, the heater 14 adjusts the temperature of the low-concentration hydrogen gas flowing into the second reactor 52 if necessary.

The treated gas is cooled in the cooler 15 and then returned to the reactor containment vessel 1, thereby reducing the hydrogen concentration in the reactor containment vessel 1. In addition, the water generated by the cooling in the cooler 15 is separated and discharged to the drain tank 16. The water generated by the cooler 15 may be returned to the reactor containment vessel 1.

As configured as described above, the seventh embodiment provides the same effect as effect (4) of the first embodiment, as well as the following effects (14) and (15).

(14) When the hydrogen gas from the reactor containment vessel 1 is measured as high-concentration hydrogen gas by the hydrogen concentration meter 65, this hydrogen gas is introduced only into the first reactor 51 filled with the treatment material 21, as shown in FIG. 9. Therefore, even if the treatment material 21 made of low-heat-generating metal oxide has low activity, it can quickly treat hydrogen in a short time because it has a high hydrogen concentration compared to the high-concentration hydrogen gas introduced into the first reactor 51. At this time, since the amount of heat generated by the low-heat-generating metal oxide of the treatment material 21 in the first reactor 51 is low, the temperature rise of the hydrogen gas, the treatment material 21, and the first reactor 51 can be suppressed.

(15) When the hydrogen gas from the reactor containment vessel 1 is measured as low-concentration hydrogen gas by the hydrogen concentration meter 65, the hydrogen gas is introduced into the second reactor 52 as shown in FIG. 10. In this case, the treatment material 22 of high heat generating metal oxide in the second reactor 52 can quickly treat the low-concentration hydrogen gas in a short time. At this time, the high heat generating metal oxide of the treatment material 22 in the second reactor 52 reacts with the low-concentration hydrogen, and thus the amount of heat generated is low, so that the temperature rise of the hydrogen gas, the treatment material 22, and the second reactor 52 can be suppressed.

Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. Furthermore, such substitutions and modifications are included in the scope and gist of the invention, as well as in the scope of the invention and its equivalents as described in the claims.

For example, the first reactor 51 of the fifth, sixth and seventh embodiments may be filled with the treatment material 21, which is a mixture of a low heat generating metal oxide treatment material 21 and a small amount of a high heat generating metal oxide treatment material 22, a low heat generating metal oxide and a small amount of a high heat generating metal oxide mixed in powder form and molded into a low heat generating mixed treatment material, or a combination of the low heat generating metal oxide treatment material 21 and the above low heat generating mixed treatment material.

In addition, the second reactor 52 in the fifth, sixth and seventh embodiments may be filled with the treatment material 22, which is a mixture of a high heat generating metal oxide treatment material 22 and a small amount of a low heat generating metal oxide treatment material 21, a high heat generating metal oxide and a small amount of a low heat generating metal oxide mixed in powder form and molded into a high heat generating mixed treatment material, or a combination of the high heat generating metal oxide treatment material 22 and the above-mentioned high heat generating mixed treatment material.

Furthermore, the first to seventh embodiments are merely examples, and the location where the hydrogen-containing gas is collected is not limited to the reactor containment vessel 1. Furthermore, the means for sending the gas is not limited to the blower 13. Furthermore, the means for measuring the hydrogen concentration is not limited to the hydrogen concentration meter 65, and a combustible gas concentration detector or the like may be used.

10...hydrogen treatment device, 11...treatment material, 12...reactor, 20...hydrogen treatment device, 21...treatment material, 22...treatment material, 30, 40...hydrogen treatment device, 50...hydrogen treatment device, 51...first reactor, 52...second reactor, 60, 70...hydrogen treatment device

Claims (5)

The present invention is configured by providing a treatment material composed of two or more types of metal oxides each having a different reaction heat, and filling one reactor with the treatment materials in a mixed state;
In the reactor, the treatment material of a low heat generating metal oxide having a small reaction heat is arranged on the upstream side, and the treatment material of a high heat generating metal oxide having a large reaction heat is arranged on the downstream side,
The hydrogen treatment device is characterized in that the low-heat-generating metal oxide, which has a small reaction heat among the metal oxides, is configured to treat hydrogen from high-concentration hydrogen gas. 2. The hydrogen treatment device according to claim 1, wherein the reactor is filled with a low heat-generating metal oxide treatment material and a high heat-generating metal oxide treatment material with a ratio gradually changing from the upstream side to the downstream side. The present invention provides a method for producing a fuel cell using a fuel cell system comprising the steps of: providing a fuel cell system including: a fuel cell that is provided with a fuel cell having ...
The reactor containing the treatment material of a low heat-producing metal oxide having a small reaction heat is arranged in series in a stage preceding the reactor containing the treatment material of a high heat-producing metal oxide having a large reaction heat ;
The hydrogen treatment device is characterized in that the low-heat-generating metal oxide, which has a small reaction heat among the metal oxides, is configured to treat hydrogen from high-concentration hydrogen gas . The present invention provides a method for producing a fuel cell using a fuel cell system comprising the steps of: providing a fuel cell system including: a fuel cell that is provided with a fuel cell having ...
The reactor containing the treatment material of a low heat generating metal oxide having a small reaction heat and the reactor containing the treatment material of a high heat generating metal oxide having a large reaction heat are configured to be switched in accordance with the hydrogen concentration of the hydrogen gas ,
The hydrogen treatment device is characterized in that the low-heat-generating metal oxide, which has a small reaction heat among the metal oxides, is configured to treat hydrogen from high-concentration hydrogen gas . A hydrogen processing method comprising: filling a single reactor with a mixture of processing materials each composed of two or more types of metal oxides each having a different heat of reaction; arranging the processing material of the low-heat-producing metal oxide having a small heat of reaction on the upstream side of the reactor and the processing material of the high-heat-producing metal oxide having a large heat of reaction on the downstream side of the reactor ; and using the low-heat-producing metal oxide having a small heat of reaction among the metal oxides to process hydrogen in a high-concentration hydrogen gas.

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