CN104470848A

CN104470848A - Hydrogen recombiner

Info

Publication number: CN104470848A
Application number: CN201380039211.XA
Authority: CN
Inventors: S.M.阿兹兹; D.格里梅特
Original assignee: Pratt and Whitney Rocketdyne Inc
Current assignee: Aerojet Rocketdyne of DE Inc
Priority date: 2012-07-24
Filing date: 2013-03-28
Publication date: 2015-03-25
Also published as: JP2015529806A; WO2014018127A1; KR20150046005A

Abstract

A hydrogen recombiner includes a series of catalyst stages, each of the series of catalyst stages define a catalyst activity that increase as a function of a flowpath.

Description

Hydrogen recombiner

The disclosure requires that the open sequence number of US provisional patent submitted on July 24th, 2012 is the right of priority of 61/675,155.

Technical field

The disclosure relates to a kind of improvement type autocatalytically hydrogen compound non-ly active to remove hydrogen from the containment vessel (containment vessel) of nuclear reactor is inner in dehydration (loss of coolant) situation.

Background technology

Nuclear power plants contributes to electrical production very efficiently.Light-water cooled nuclear reactor (LWR) is designed to make to be down to minimum because of loss of coolant accident (" LOCA ") to the threat that the integrity of reactor housing causes.LOCA can cause hot water and vapo(u)r blasting to enter in reactor housing atmosphere (containment atmosphere).Unless adopt the system from reactor housing heat radiation, otherwise the pressure and temperature in reactor housing may exceed design limit and rise.

In addition, LOCA also may cause reactor core expose and thus cause fuel temperature to increase, and zirconium alloy just may be caused when zirconium alloy and residue vapor react with to be oxidized.This reaction is heat release and produces the hydrogen that can be emitted to along with steam in reactor housing atmosphere.The quality release rate of hydrogen can be the grade of Kilograms Per Second.Make hydrogen activity maintain system under spontaneous combustion restriction unless adopted, otherwise just can produce potential combustible gas mixture in reactor containment.

Current LWR very safety and fail safe operation is provided for supply of electric power, process water and the minimum dependency of operator's behavior to eliminate the impact of LOCA.Except the cooling selection of various active (active), many LWR adopt non-active (passive) system from reactor housing atmosphere transferring heat.Such as, some reactors utilize steel containment vessel container and promote heat transfer from the outside water cooling of high level tank.Heat from reactor housing atmosphere is passed to containment vessel by natural convection.Owing to coming from the hot steam of rent (break) and air mixed and rising to the top of reactor housing, be then cooled by the cold reactor housing of contact.The denser mixture of refrigerant declines thus starts the process of natural circulation, the flowing near its mesospore downwards and the flowing of middle section upwards.After initial blowing down (blow-down) period, pressure and temperature in reactor housing increases, until the condensing rate of steam on cold reactor housing and other cold surface equals the steam rate from rent discharge.

Nuclear reactor also utilizes various passive system to alleviate hydrogen accumulation.Such as, before being initiated or period pre-inerting in reactor housing, produce oxygen-lean atmosphere.Rare gas element (normally nitrogen) is injected in reactor housing to replace air thus to be reduced to by oxygen activity under the level needed for hydrogen burning.

Another passive system is hydrogen recombiner.Hydrogen recombiner makes hydrogen and oxygen compound to produce water thus to reduce the hydrogen activity in reactor housing.Relative to hot recombiner, autocatalytically recombiner is self-running and does not need external impetus thus right and wrong are active.

In order to effectively work, hydrogen recombiner needs relatively high air rate.The natural circulation of conventional use safety shell atmosphere, to reach reactor housing cooling, cannot produce sufficiently high flow rate usually to obtain effective non-active hydrogen recombiner to process large reactor housing volume.Come from the reaction between hydrogen and oxygen and the raised temperature produced in catalytic recombiner facilitates local convection.This can produce compared with the larger convection flow of the flowing only produced by natural circulation in recombiner.

Accompanying drawing explanation

According to the following specific descriptions of disclosed non-limiting example, various feature will become apparent to those skilled in the art.Accompany this specifically described accompanying drawing can be described as follows briefly:

Fig. 1 is the schematic diagram of the hydrogen recombiner according to a kind of disclosed non-limiting example;

Fig. 2 is the schematic diagram of the hydrogen recombiner according to another kind of disclosed non-limiting example;

Fig. 3 is the schematic diagram of the hydrogen recombiner according to another kind of disclosed non-limiting example;

Fig. 4 is the schematic diagram of the hydrogen recombiner according to another kind of disclosed non-limiting example;

Fig. 5 is the schematic diagram of the hydrogen recombiner according to another kind of disclosed non-limiting example; And

Fig. 6 is the schematic diagram of the hydrogen recombiner according to another kind of disclosed non-limiting example.

Embodiment

Fig. 1 schematically illustrates hydrogen recombiner 30, and it generally includes shell 31 and a series of catalyst grades in it (catalyst stage) 32A, 32B, 32C etc.Although show three, it is to be appreciated that any amount all can be benefited therefrom.Every one-level in described a series of catalyst grade 32A, 32B, 32C all limits the catalyst activity (catalyst activity) increased progressively along with the flowing-path (flowpath) from entrance 34 to outlet 36.Each successive level in described a series of catalyst grade 32A, 32B, 32C reduces the activity of hydrogen, so that the output of hydrogen recombiner 30 has hydrogen activity level lower substantially.

Reaction of recombination (H2+2O2=2H2O) produces heat at catalyst surface place.H2 is active larger, and the heat produced is more, so that the catalyst activity that can limit relative to service temperature (such as lower than the temperature of about 932F (500C)) in every grade in described a series of catalyst grade 32A, 32B, 32C, so that effectively except dehydrogenation avoids again hydrogen detonation.

Although be that operationally right and wrong are active, but hydrogen recombiner 30 can comprise fan 38 extraly (schematically shows; Fig. 2) to promote flowing.In other words, even without fan 38, hydrogen recombiner 30 also can operate effectively, and passing through fan 38 can be able to not operate by being exclusively used in the uninterruptible power supply (UPS) of fan 38, if or the operational words of external power source, fan 38 also can operate to increase efficiency.

Generally speaking, the first step 32A in described a series of catalyst grade is customized into for relatively low catalytic activity, because the first step 32A in described a series of catalyst grade is exposed to relatively high hydrogen richness.In other words, the first step 32A in described a series of catalyst grade has relatively low catalyst activity, so that surface temperature remains under preset temperature.For this SA catalyzer, the material than precious metal cheapness can be utilized.Middle catalyst grade 32B provides relatively medium catalyst activity.Last catalyst grade 32C provides relatively high catalyst activity so that removing is in SA hydrogen, so that surface temperature maintains under preset temperature.

Catalyst activity in every one-level in described a series of catalyst grade 32A, 32B, 32C such as can be covered by the partially catalyzed agent on heat conduction substrate and control, so that heat passes from catalyst surface by this matrix, and convection current will be dispelled the heat from this matrix.In non-limiting example disclosed in another, metal alloy net can be placed on catalyst surface or be embedded in it so that enhance heat transfer.Various catalyst arrangement or its combination can be provided alternatively or extraly.

In addition, various catalyzer geometric configuration and orientation (geometries and orientations) can be used in the every one-level in described a series of catalyst grade 32A, 32B, 32C either individually or in combination.In a kind of disclosed non-limiting example, in the every one-level in described a series of catalyst grade 32A, 32B, 32C, utilize vertically-oriented catalyst plates 40 (Fig. 3).In non-limiting example disclosed in another, in the every one-level in described a series of catalyst grade 32A, 32B, 32C, utilize vertically-oriented bar or pipe 50 (Fig. 4).In another disclosed non-limiting example, in the every one-level in described a series of catalyst grade 32A, 32B, 32C, utilize spherical array 60 (Fig. 5).In non-limiting example disclosed in again, in the every one-level in described a series of catalyst grade 32A, 32B, 32C, utilize vertically-oriented coiled sheet (coiled sheet; Coiled sheet) 70 (Fig. 6).Equally, it is to be appreciated that various other is arranged and combination will be benefited thus.

Thus, hydrogen recombiner 30 at different levels easily heat radiation not have power and emergency power can with all can preventing overheated in two kinds of situations and losing efficacy.In addition, owing to easily eliminating the hydrogen capacity of more than ten times compared with the hydrogen recombiner of routine, so hydrogen recombiner 30 can reduce required hydrogen recombiner quantity, thus cost of investment can be reduced.

In the context (especially at the context of claims) of specification sheets, the use of term " " and " " and " described " and similar pronoun should be construed as containing single and a plurality of, unless other in the text explanation or based on context contradictory particularly.Adjective " approximately " is used to comprise values listed and have the implication (such as it comprises the error degree relevant with the measurement of concrete quantity) determined by context in conjunction with quantity.All scopes disclosed herein include end points, and end points can be bonded to each other independently.It should be appreciated that relative positional terms, such as "front", "rear", " on ", the normal operational attitude of D score, " on ", " under " etc. reference tool (vehicle) and should not be counted as other restriction.

Although different non-limiting examples has by the parts specifically illustrated, but embodiments of the invention are not limited to these distinctive combinations.May use from some parts of any embodiment in any non-limiting example or feature and from the feature of any embodiment in other non-limiting example or the combination of parts.

It is to be appreciated that several figure running through shown, like reference numerals refers to correspondence or like.Although also it should be appreciated that disclosing distinctive parts in illustrated embodiment is arranged, but other setting also will be benefited thus.

Although illustrate, describe and require that distinctive sequence of steps, but it should be understood that unless explicitly stated otherwise, otherwise step with any order, be individually or in combination performed, and will can be benefited from the disclosure.

Description is above exemplary instead of is defined within it.Disclosed herein is various non-limiting example, but one, this area ordinary skill will recognize, the various modifications and variations according to above-mentioned instruction should be listed in the scope of claims.Therefore, it should be appreciated that within the scope of the appended claims, the disclosure can be realized in the mode outside peculiarly describing.For this reason, claims should be studied to determine true scope and content.

Claims

1. a hydrogen recombiner, comprising:

A series of catalyst grade, every grade in described a series of catalyst grade all limits the catalyst activity increased progressively along with flowing-path.

2. hydrogen recombiner according to claim 1, is characterized in that, described catalyst activity increases progressively from the inlet to the outlet.

3. hydrogen recombiner according to claim 2, is characterized in that, also comprises the fan of contiguous described entrance.

4. hydrogen recombiner according to claim 1, is characterized in that, limits described catalyst activity relative to service temperature.

5. hydrogen recombiner according to claim 4, is characterized in that, described service temperature is less than hydrogen fuming-off temperature.

6. the non-method removing hydrogen from the containment vessel inside of nuclear reactor, comprising actively:

Be placed on by a series of catalyst grade in described containment vessel, described a series of catalyst grade limits the catalyst activity increased progressively along with flowing-path.

7. method according to claim 6, is characterized in that, is also included in maintain service temperature in every grade in described a series of catalyst grade and be less than hydrogen fuming-off temperature.

8. method according to claim 6, is characterized in that, also comprises upstream fan being placed on described a series of catalyst grade.