NO170575B - TOTRINNS AMMONIA CONVERSOR - Google Patents
TOTRINNS AMMONIA CONVERSOR Download PDFInfo
- Publication number
- NO170575B NO170575B NO880535A NO880535A NO170575B NO 170575 B NO170575 B NO 170575B NO 880535 A NO880535 A NO 880535A NO 880535 A NO880535 A NO 880535A NO 170575 B NO170575 B NO 170575B
- Authority
- NO
- Norway
- Prior art keywords
- fuel
- briquette
- slits
- fuel briquette
- heat exchanger
- Prior art date
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- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 title abstract 4
- 229910021529 ammonia Inorganic materials 0.000 title abstract 2
- 239000000446 fuel Substances 0.000 claims description 88
- 239000004484 Briquette Substances 0.000 claims description 52
- 239000000919 ceramic Substances 0.000 claims description 7
- 229910052751 metal Inorganic materials 0.000 claims description 2
- 239000002184 metal Substances 0.000 claims description 2
- 230000002093 peripheral effect Effects 0.000 claims 1
- 239000003054 catalyst Substances 0.000 abstract 2
- 230000005540 biological transmission Effects 0.000 abstract 1
- 238000010276 construction Methods 0.000 abstract 1
- 230000002349 favourable effect Effects 0.000 abstract 1
- 239000012495 reaction gas Substances 0.000 abstract 1
- 230000000694 effects Effects 0.000 description 5
- 239000002826 coolant Substances 0.000 description 4
- 230000004992 fission Effects 0.000 description 3
- 239000000463 material Substances 0.000 description 2
- 239000003758 nuclear fuel Substances 0.000 description 2
- 239000004033 plastic Substances 0.000 description 2
- 230000005855 radiation Effects 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000000712 assembly Effects 0.000 description 1
- 238000000429 assembly Methods 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 229910010293 ceramic material Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- OOAWCECZEHPMBX-UHFFFAOYSA-N oxygen(2-);uranium(4+) Chemical compound [O-2].[O-2].[U+4] OOAWCECZEHPMBX-UHFFFAOYSA-N 0.000 description 1
- 230000003071 parasitic effect Effects 0.000 description 1
- FCTBKIHDJGHPPO-UHFFFAOYSA-N uranium dioxide Inorganic materials O=[U]=O FCTBKIHDJGHPPO-UHFFFAOYSA-N 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01C—AMMONIA; CYANOGEN; COMPOUNDS THEREOF
- C01C1/00—Ammonia; Compounds thereof
- C01C1/02—Preparation, purification or separation of ammonia
- C01C1/04—Preparation of ammonia by synthesis in the gas phase
- C01C1/0405—Preparation of ammonia by synthesis in the gas phase from N2 and H2 in presence of a catalyst
- C01C1/0417—Preparation of ammonia by synthesis in the gas phase from N2 and H2 in presence of a catalyst characterised by the synthesis reactor, e.g. arrangement of catalyst beds and heat exchangers in the reactor
- C01C1/0423—Cold wall reactors
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
- B01J8/02—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds
- B01J8/04—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid passing successively through two or more beds
- B01J8/0403—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid passing successively through two or more beds the fluid flow within the beds being predominantly horizontal
- B01J8/0407—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid passing successively through two or more beds the fluid flow within the beds being predominantly horizontal through two or more cylindrical annular shaped beds
- B01J8/0415—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid passing successively through two or more beds the fluid flow within the beds being predominantly horizontal through two or more cylindrical annular shaped beds the beds being superimposed one above the other
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01C—AMMONIA; CYANOGEN; COMPOUNDS THEREOF
- C01C1/00—Ammonia; Compounds thereof
- C01C1/02—Preparation, purification or separation of ammonia
- C01C1/04—Preparation of ammonia by synthesis in the gas phase
- C01C1/0405—Preparation of ammonia by synthesis in the gas phase from N2 and H2 in presence of a catalyst
- C01C1/0417—Preparation of ammonia by synthesis in the gas phase from N2 and H2 in presence of a catalyst characterised by the synthesis reactor, e.g. arrangement of catalyst beds and heat exchangers in the reactor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
- B01J2208/00008—Controlling the process
- B01J2208/00017—Controlling the temperature
- B01J2208/00106—Controlling the temperature by indirect heat exchange
- B01J2208/00168—Controlling the temperature by indirect heat exchange with heat exchange elements outside the bed of solid particles
- B01J2208/00203—Coils
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
- B01J2208/00008—Controlling the process
- B01J2208/00017—Controlling the temperature
- B01J2208/00106—Controlling the temperature by indirect heat exchange
- B01J2208/00168—Controlling the temperature by indirect heat exchange with heat exchange elements outside the bed of solid particles
- B01J2208/00212—Plates; Jackets; Cylinders
- B01J2208/00221—Plates; Jackets; Cylinders comprising baffles for guiding the flow of the heat exchange medium
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Analytical Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Devices And Processes Conducted In The Presence Of Fluids And Solid Particles (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
- Catalysts (AREA)
- Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
- Nitrogen Condensed Heterocyclic Rings (AREA)
- Sorption Type Refrigeration Machines (AREA)
- Glass Compositions (AREA)
- Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
Abstract
Description
Keramisk brenselbrikett for kjernereaktorer. Ceramic fuel briquette for nuclear reactors.
Oppfinnelsen angår keramiske brenselbriketter for anvendelse i en stavformet brenselenhet for kjernereaktorer. Slike brenselenheter er tilboyelige til i et miljo med hoy temperatur og strålingsintensitet å utvikle tangensielle trykkspenninger. The invention relates to ceramic fuel briquettes for use in a rod-shaped fuel unit for nuclear reactors. Such fuel units are prone to develop tangential compressive stresses in an environment with high temperature and radiation intensity.
Stavformede brenselenheter har funnet utstrakt anvendelse i reaktorer som arbeider med trykkvann eller kokende vann som kjolemiddel, og også i gassavkjolte reaktorer. Slike brenselenheter består som regel av en rorformet kapsling med et antall deri anordnede, hovedsakelig sylindriske, keramiske brenselbriketter. Endepropper eller en endebunn anvendes for å lukke rorenes ender og derved danne en tett omhylling rundt brenselbrikettene. Kapslingen hindrer tap av kjernebrensel og avgivelse av spaltningsprodukter til reaktorkjblemidlet og beskytter dessuten brenselbrikettene mot korrosjon av kjolemidlet og gir brenselenheten mekanisk styrke slik at den hindres fra å knekke eller endre sin forutbestemte beliggenhet i en samling brenselenheter. De individuelle brenselenheter ordnes i grupper, og flere slike grupper danner tilsammen en reaktorkjerne som er istand til å underholde en kjedespaltningsreaksjon. Rod-shaped fuel units have found extensive use in reactors that work with pressurized water or boiling water as coolant, and also in gas-cooled reactors. Such fuel units usually consist of a tube-shaped enclosure with a number of mainly cylindrical ceramic fuel briquettes arranged therein. End plugs or an end base are used to close the ends of the rudders and thereby form a tight envelope around the fuel briquettes. The casing prevents the loss of nuclear fuel and release of fission products to the reactor coolant and also protects the fuel briquettes from corrosion by the coolant and provides the fuel assembly with mechanical strength so that it is prevented from breaking or changing its predetermined location in an assembly of fuel assemblies. The individual fuel units are arranged in groups, and several such groups together form a reactor core capable of sustaining a chain fission reaction.
Det har lenge .vært et problem i forbindelse med anvendelsen av slike stavformede brenselenheter å opprettholde kapslingens integritet under hoye temperaturer og bestrålinger. Ved slike betingelser utsettes de vanlig anvendte brenselbriketter av den keramiske type, f.eks. urandioxyd, for en vekst i radiell retning, og det fremkalles derved store tangensialkrefter i deres radielle omkretsområder når brenselbrikettene hindres i å utvide seg på grunn av den omgivende kapsling som bare utvider seg i mindre grad. Brenselbrikettenes evne til å fremkalle og utove tangensielle trykkrefter bestemmer den ovre grense for de spenninger som oppstår i brikettene og kapslingen. I virkeligheten er det kapslingen som ved å begrense brenselbrikettens vekst, skaper den tangensielle trykkspenning i denne, og det fremkalles dessuten en tangensiell strekkspenning i kapslingsmaterialet på grunn av dens mindre vekst. It has long been a problem in connection with the use of such rod-shaped fuel units to maintain the integrity of the enclosure under high temperatures and irradiation. Under such conditions, the commonly used fuel briquettes of the ceramic type, e.g. uranium dioxide, for a growth in the radial direction, and large tangential forces are thereby induced in their radial circumferential regions when the fuel briquettes are prevented from expanding due to the surrounding casing which only expands to a lesser extent. The fuel briquettes' ability to induce and release tangential pressure forces determines the upper limit for the stresses that arise in the briquettes and the casing. In reality, it is the casing which, by limiting the fuel briquette's growth, creates the tangential compressive stress in it, and a tangential tensile stress is also induced in the casing material due to its smaller growth.
Store, tangensielle strekkspenninger i kapslingen medforer ofte kapslingsbrudd med derav folgende tap av kjernebrensel og spaltningsprodukter til reaktorens kjolemiddel. Den med slike tap forbundne store og særdeles alvorlige fare for sikkerheten er velkjent innen reaktorteknikken og har forårsaket at omfattende sikkerhetsforan-staltninger er blitt foretatt i forbindelse med eksisterende reaktorer. Large, tangential tensile stresses in the enclosure often lead to enclosure rupture with consequent loss of nuclear fuel and fission products to the reactor's coolant. The large and particularly serious safety hazard associated with such losses is well known in reactor technology and has caused extensive safety measures to be taken in connection with existing reactors.
En enkel måte å fjerne risikoen for kapslingsbrudd på er å oke kapslingens veggtykkelse, hvorved de deri fremkomne, spesifikke strekkspenninger minskes. En slik losning medforer imidlertid andre uheldige virkninger idet mengden av parasittisk neutronabsorpsjon i brenselenheten okes og varmeoverforingen fra brenselenhetene til reaktorkjole-midlet nedsettes på grunn av det okede temperaturfall over kapslings-veggen. A simple way to remove the risk of enclosure breakage is to increase the wall thickness of the enclosure, whereby the resulting specific tensile stresses are reduced. Such a discharge, however, entails other adverse effects as the amount of parasitic neutron absorption in the fuel unit is increased and the heat transfer from the fuel units to the reactor jacket is reduced due to the increased temperature drop across the enclosure wall.
Ved å oke klaringen mellom brenselbrikettene og kapslingen kan det riktignok fås et ekspansjonsrom for brenselbrikettene, hvorved påvirkningen mellom kapslingen og en voksende brenselbrikett minskes. En slik klaring minsker imidlertid varmeovefroringen fra brenselstaven på grunn av de store temperaturfall som oppstår mellom briketten og kapslingen. Intim kontakt mellom kapslingen og brenselbrikettene er derfor nodvendig for opprettholdelse av den storst muligevarmeover-foringshastighet uten altfor hoye temperaturer 'i brenselbrikettene. By increasing the clearance between the fuel briquettes and the casing, an expansion space can be obtained for the fuel briquettes, whereby the influence between the casing and a growing fuel briquette is reduced. Such clearance, however, reduces the heat transfer from the fuel rod due to the large temperature drops that occur between the briquette and the casing. Intimate contact between the casing and the fuel briquettes is therefore necessary to maintain the greatest possible heat transfer rate without excessively high temperatures in the fuel briquettes.
Fore .Liggende oppfinnelse tar derfor generelt sikte på å tilveiebringe en brenselbrikett for brenselenheter av stavtypen og som under bruk utvikler et minimum av tangensielle trykkspenninger. The present invention therefore generally aims to provide a fuel briquette for fuel units of the rod type and which during use develops a minimum of tangential compressive stresses.
Oppfinnelsen tar videre sikte, .på å tilveiebringe en brenselbrikett for anvendelse i en brenselenhet av stavtypen slik at kapslingen under drift utsettes for lavere tangensielle strekkspenninger enn hva som tidligere har vært tilfelle ved anvendelse av kjente brenselbriketter. The invention further aims at providing a fuel briquette for use in a fuel unit of the rod type so that the casing is exposed during operation to lower tangential tensile stresses than has previously been the case when using known fuel briquettes.
Oppfinnelsen angår derfor en keramisk brenselbrikett for anvendelse i en stavformet brenselenhet for kjernereaktorer, hvorved brenselbriketten har en hovedsakelig sylindrisk, utvendig sideoverflate og er anordnet inne i en rorformet metallkapsling, og briketten er særpreget ved at den har en rekke langsgående, radiale slisser som er anordnet i den utvendige sideoverflate og som hver har en dybde som er vesentlig storre enn dens bredde, idet slissene har avrundede rotender for å minske risikoen for dannelse av sprekker i brenselbriketten på grunn av slissene som danner ekspansjonsrom for vekst av brenselbriketten for derved å minske de. periferistrekkspenninger som brenselbriketten forårsaker i kapslingen. The invention therefore relates to a ceramic fuel briquette for use in a rod-shaped fuel unit for nuclear reactors, whereby the fuel briquette has a mainly cylindrical, external side surface and is arranged inside a tube-shaped metal casing, and the briquette is characterized by having a series of longitudinal, radial slits which are arranged in the external side surface and each of which has a depth that is significantly greater than its width, the slots having rounded root ends to reduce the risk of cracks forming in the fuel briquette due to the slots forming expansion space for the growth of the fuel briquette to thereby reduce them. circumferential tensile stresses that the fuel briquette causes in the casing.
På tegningen representerer In the drawing represents
fig. 1 en perspektivskisse av en typisk, kjent brenselstav med ringformet tverrsnitt og med visse deler avdekket, fig. 1 is a perspective sketch of a typical, known fuel rod with an annular cross-section and with certain parts uncovered,
fig. 2 en perspektivskisse av en brenselbrikett hvis ytre sylinderoverflate har langsgående slisser i overensstemmelse med foreliggende oppfinnelse, og fig. 2 a perspective sketch of a fuel briquette whose outer cylinder surface has longitudinal slits in accordance with the present invention, and
fig. 3 på samme måte en perspektivskisse av en brenselbrikett med ringformet tverrsnitt og med langsgående slisser på såvel den indre som ytre sylinderoverflate i overensstemmelse med en utforelsesform av oppfinnelsen. fig. 3, in the same way, a perspective sketch of a fuel briquette with an annular cross-section and with longitudinal slits on both the inner and outer cylinder surface in accordance with an embodiment of the invention.
På grunn av de foreliggende brenselbriketters radielt orienterte, langsgående slisser med relativt stor dybde sammenlignet med bredden i den ytre. sylindriske overflate, eller både i den ytre og indre sylindriske overflate for en brenselbrikett med ringformet tverrsnitt, minskes de tangensielle trykkspenninger som under drift oppstår i briketten på grunn av dens inneslutning i en rorformet kapslLng under hoye temperaturer og strålingsintensitet. Minskningen av trykkspenningene i "brenselbriketten adfolges av en tilsvarende minskning av strekkspenningene i- brenselkapslingen, hvorved oppfinnelsens hovedformål oppnås. Due to the present fuel briquettes' radially oriented, longitudinal slits with a relatively large depth compared to the width in the outer. cylindrical surface, or both in the outer and inner cylindrical surface for a fuel briquette with an annular cross-section, the tangential compressive stresses which occur in the briquette during operation due to its encasement in a tube-shaped casing under high temperatures and radiation intensity are reduced. The reduction of the compressive stresses in the fuel briquette is followed by a corresponding reduction of the tensile stresses in the fuel casing, whereby the main purpose of the invention is achieved.
For å lette forståelsen av oppfinnelsen vises til fig. 1 som gjengir en typisk brenselstav inneholdende vanlige brenselbriketter med ringformet tverrsnitt. Keramiske brenselbriketter 1 med et sentralt gjennomgående hull er anbragt i en rorformet kapsling 2 som danner stotte for brenselbrikettene og beskytter dem mot reaktorkjole-midlets korroderende og eroderende virkninger. Kapslingen 2 er lukket i begge ender med propper 3 og ^t- som kan være forsynt med forlengelser hhv. 5 og 6 for å lette monteringen av brenselstaven i en gruppe brenselenheter. Proppene 3 og h kan være tett forbundet med kapslingen 2 ved hjelp av sveisesommer 7 langs de tilstotende avslutninger av proppen og kapslingen. To facilitate the understanding of the invention, reference is made to fig. 1 which reproduces a typical fuel rod containing ordinary fuel briquettes with an annular cross-section. Ceramic fuel briquettes 1 with a central through hole are placed in a tube-shaped casing 2 which forms a support for the fuel briquettes and protects them against the corrosive and erosive effects of the reactor jacket agent. The enclosure 2 is closed at both ends with plugs 3 and ^t- which can be provided with extensions respectively. 5 and 6 to facilitate the assembly of the fuel rod in a group of fuel units. The plugs 3 and h can be tightly connected to the housing 2 by means of welding summer 7 along the adjacent ends of the plug and the housing.
Fig.2 viser en ringformet brenselbrikett 8 med langsgående slisser 9 jevnt fordelt over den ytre sylinderoverflate. Selv om det foretrekkes å benytte en ringformet brenselbrikett på grunn av den kjente minskning av trykkspenningene som fås ved å utstyre briketten med store sentrale hull, medvirker de ifolge oppfinnelsen anordnede langsgående slisser også til effektivt å minske de trykkspenninger som fremkommer i massive, sylindriske brenselbriketter. De trykk-minskende virkninger av de sentrale hull og slisser er imidlertid •additive, og anvendelse av begge i samme brenselenhet bevirker en storre netto trykkminskning enn den som ville kunne oppnås bare ved anvendelse av langsgående slisser. Fig.2 shows a ring-shaped fuel briquette 8 with longitudinal slits 9 evenly distributed over the outer cylinder surface. Although it is preferred to use a ring-shaped fuel briquette due to the known reduction in compressive stresses obtained by equipping the briquette with large central holes, the longitudinal slits arranged according to the invention also help to effectively reduce the compressive stresses that occur in massive, cylindrical fuel briquettes. The pressure-reducing effects of the central holes and slits are, however, additive, and the use of both in the same fuel unit results in a greater net pressure reduction than could be achieved by the use of longitudinal slits alone.
Fig. 3 viser en annen utforelsesform ifolge oppfinnelsen hvor en ringformet brenselbrikett 10 rundt sin indre overflate er utstyrt med jevnt fordelte, langsgående slisser 11 og også med jevnt fordelte, langsgående slisser 12 rundt den ytre overflate. Slissene 11 er vinkelforskjbvet mellom slissene 12 for å nedsette den av slissene forårsakede styrkeminskning i briketten til et minimum samtidig som det oppnås en maksimal minskning av ringspenningene. Anvendelsen av såvel innvendige som utvendige slisser gjor det mulig å nedsette det antall Fig. 3 shows another embodiment according to the invention where a ring-shaped fuel briquette 10 around its inner surface is equipped with evenly spaced, longitudinal slots 11 and also with evenly spaced, longitudinal slots 12 around the outer surface. The slits 11 are angularly offset between the slits 12 in order to reduce the reduction in strength caused by the slits in the briquette to a minimum while at the same time achieving a maximum reduction of the ring stresses. The use of both internal and external slots makes it possible to reduce that number
utvendige slisser som er nodvendig for å oppnå en bestemt minskning av ringspenningene, og minsker også den temperaturøkning som ellers ville oppstå i brikettens sentrale område på grunn av de varmeoverforings-tap som kan tilskrives minskningen av den effektive varmeoverforings-flate mellom brenselbriketten og kapslingen som folge av nærværet av slisser i den innvendige sylinderflate. Den radielle tykkelse til en external slots which are necessary to achieve a certain reduction in ring stresses, and also reduce the temperature increase that would otherwise occur in the central area of the briquette due to the heat transfer losses attributable to the reduction of the effective heat transfer surface between the fuel briquette and the casing as a result of the presence of slots in the inner cylinder surface. The radial thickness of a
ringformet brenselbrikett kan folgelig gjbres noe stbrre hvorved fås en bedre romutnyttelse innenfor en hvilken som helst gitt temperatur-begrensning. ring-shaped fuel briquettes can therefore be made somewhat larger, which results in a better use of space within any given temperature limitation.
Slissenes antall og bredde velges slik at minst mulig av brenselbrikettens volum går tapt samtidig som oppbygningen av farlige om-kretsspenninger i briketten unngås under brikettens brukstid. Den på grunn av slissene sikrede fulle beskyttelse overfor store trykkspenninger kan bare oppnås så lenge slissene er åpne. Under sin vekst er brenslet tilbbyelig til å lukke slissene under samtidig utvikling av trykkspenninger. Slissenes antall og bredde står folgelig i direkte relasjon til den vektsgrad som en brenselbrikett har i lopet av sin levetid. Antallet slisser multiplisert med deres bredde representerer et ekspansjonsrom som må fylles av det voksende brensel for det kan utbve trykkspenninger på den omgivende kapsling. The number and width of the slits are chosen so that as little as possible of the fuel briquette's volume is lost, while the build-up of dangerous circuit voltages in the briquette is avoided during the briquette's useful life. The full protection against high compressive stresses ensured by the slits can only be achieved as long as the slits are open. During its growth, the fuel is prone to close the slits while simultaneously developing compressive stresses. The number and width of the slits are therefore in direct relation to the degree of weight that a fuel briquette has over the course of its lifetime. The number of slits multiplied by their width represents an expansion space that must be filled by the growing fuel before it can exert compressive stresses on the surrounding casing.
De gjenværende, uslissede deler av den ifolge fig. 2 viste brenselbrikett befinner seg i et område med hbyere temperatur hvor det keramiske materiale er meget svakere og mer plastisk enn 1 den kaldere, slissede del av briketten. Eftersom alle trykkspenninger må opptas av den uslissede del av brenslet som befinner seg ved temperaturer hvor plastisk flytning gjor seg gjeldende, blir netto-effekten at brenselbriketten ikke kan utbve store trykkspenninger ved hoye arbeidstemperaturer. Brenselbriketten ifolge fig. 3 som har slisser både i hoye og lave temperaturområder, kan heller ikke utbve store trykkspenninger selv ved lave temperaturer. The remaining, unslitted parts of the according to fig. The fuel briquette shown in 2 is in an area of higher temperature where the ceramic material is much weaker and more plastic than 1 the colder, slotted part of the briquette. Since all compressive stresses must be taken up by the unsliced part of the fuel which is at temperatures where plastic flow takes effect, the net effect is that the fuel briquette cannot experience large compressive stresses at high working temperatures. The fuel briquette according to fig. 3, which has slits in both high and low temperature areas, cannot develop large compressive stresses even at low temperatures.
Full beskyttelse mot trykk- og strekkspenninger under brenselbrikettens og kapslingens samlede levetid er i enkelte tilfeller unbdvendig, og i enkelte tilfeller sogar uonsket, Idet et visst nivå av strekkspenninger kan tolereres mot slutten av brenslets levetid. Dette er spesielt tilfelle dersom det bnskes et maksimalt brenselvolum i brikettene. Slissenes antall og bredde kan da velges slik at det av slissene dannede ekspansjonsrom er utilstrekkelig for brenselbrikettens samlede levetid og slik at slissene med andre ord vokser sammen. De trykkspenninger som utvikles efter at slissene har vokst sammen, blir da betydelig mindre enn de strekkspenninger som ville ha blitt utviklet i en uslisset, men forbvrlg identisk brenselbrikett på samme tidspunkt av dens virksomme levetid. Denne forskjell i trykkspenninger oppstår til tross for at brenselbrikettens slisser er blitt sammenvokst idet slissene effektivt opp-tar all brikettvekst oppstått for de lukkes. Slissede brenselbriketter ifolge oppfinnelsen kan således utformes på en slik måte at de tilveiebringer en hvilken som helst onsket grad av spennings-minskning avhengig av de særlige krav som stilles til en bestemt type brenselstaver. Full protection against compressive and tensile stresses during the combined lifetime of the fuel briquette and casing is in some cases necessary, and in some cases even undesirable, as a certain level of tensile stresses can be tolerated towards the end of the fuel's lifetime. This is especially the case if a maximum fuel volume is required in the briquettes. The number and width of the slits can then be chosen so that the expansion space formed by the slits is insufficient for the overall lifetime of the fuel briquette and so that the slits, in other words, grow together. The compressive stresses that develop after the slits have grown together are then significantly less than the tensile stresses that would have been developed in an unslitted but relatively identical fuel briquette at the same point in its useful life. This difference in compressive stresses occurs despite the fact that the fuel briquette's slits have grown together, as the slits effectively absorb all briquette growth that occurred before they were closed. Slotted fuel briquettes according to the invention can thus be designed in such a way that they provide any desired degree of voltage reduction depending on the special requirements placed on a specific type of fuel rods.
Valget av slissedybde krever et kompromiss mellom fremstill-ingsmulighet, brikettstyrke, minskning av brenselvolum og minskning av de på kapslingen under drift utviklede trykkspenninger. Da den relative betydning av disse faktorer vil variere fra tilfelle til tilfelle, kan det ikke sies at en bestemt slissedybe er den ideelle. Slissedybder som utgjor omtrent halvparten av den ringformede brensel-briketts tykkelse, har ofte vist seg å representere et godt kompromiss mellom disse faktorer. Slisser med mindre dybde kan anvendes dersom det kreves en mindre minskning av trykkspenningene eller dersom det kreves en brikett med storre styrke for å motstå skader som kan oppstå under håndteringen. Slisser med storre dybde enn den ringformede briketts halve veggtykkelse oker på den annen side risikoen for at skader kan oppstå under håndteringen, og brikettenes brenselvolum nedsettes. The choice of slot depth requires a compromise between manufacturability, briquette strength, reduction of fuel volume and reduction of the compressive stresses developed on the casing during operation. As the relative importance of these factors will vary from case to case, it cannot be said that a particular slot depth is the ideal. Slot depths that make up approximately half of the ring-shaped fuel briquette's thickness have often been shown to represent a good compromise between these factors. Slots with a smaller depth can be used if a smaller reduction in compressive stresses is required or if a briquette with greater strength is required to withstand damage that may occur during handling. Slots with a greater depth than the ring-shaped briquette's half wall thickness, on the other hand, increase the risk of damage occurring during handling, and the briquettes' fuel volume is reduced.
For briketter hvor bare den ene overflate er utstyrt med slisser, som vist på fig. 2, er det onskelig at antallet slisser er minst seks. For å nedsette virkningen av friksjonen mellom briketten og kapslingen på de deler av briketten som ligger mellom slissene, foretrekkes det imidlertid å benytte 8-12 slisser. Dersom briketten er utstyrt med slisser både på utsiden og innsiden, som vist på fig.3, er det tilstrekkelig med h - 6 slisser i hver overflate. For briquettes where only one surface is equipped with slits, as shown in fig. 2, it is desirable that the number of slots is at least six. However, in order to reduce the effect of the friction between the briquette and the casing on the parts of the briquette that lie between the slots, 8-12 slots are preferred. If the briquette is equipped with slits on both the outside and the inside, as shown in fig.3, it is sufficient to have h - 6 slits in each surface.
Tilvirkningen av brenselbriketter med slisser ifolge oppfinnelsen krever kjennskap til vekstegenskapene til det spesielle, pres-sede brenselmateriale som anvendes i brikettene. Vekstegenskapene til den spesielle, rorformede kapsling hvori brenselbrikettene skal inn-fores, må naturligvis også være kjente da det er forskjellen i vekst mellom den rorformede kapsling og de deri forekommende brenselbriketter som er opphavet til de spenninger som skal elimineres ifolge oppfinnelsen. Slissenes antall og storrelse må således bestemmes efter bedommelse som kan veksle fra tilfelle til tilfelle, og en enkelt rekke av numeriske verdier vil ikke være generelt anvendelig under alle forhold. The production of fuel briquettes with slots according to the invention requires knowledge of the growth properties of the special, pressed fuel material used in the briquettes. The growth characteristics of the special, tube-shaped enclosure in which the fuel briquettes are to be inserted must of course also be known, as it is the difference in growth between the tube-shaped enclosure and the fuel briquettes occurring therein which is the origin of the stresses to be eliminated according to the invention. The number and size of the slits must thus be determined according to judgment which can change from case to case, and a single series of numerical values will not be generally applicable under all conditions.
Claims (3)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19873708781 DE3708781A1 (en) | 1987-03-18 | 1987-03-18 | TWO-STAGE AMMONIA CONVERTER WITH AT LEAST ONE CATALYST BED WITH HEAT EXCHANGER INSIDE ITSELF |
Publications (4)
Publication Number | Publication Date |
---|---|
NO880535D0 NO880535D0 (en) | 1988-02-08 |
NO880535L NO880535L (en) | 1988-09-19 |
NO170575B true NO170575B (en) | 1992-07-27 |
NO170575C NO170575C (en) | 1992-11-04 |
Family
ID=6323361
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
NO880535A NO170575C (en) | 1987-03-18 | 1988-02-08 | TOTRINNS AMMONIA CONVERSOR |
Country Status (13)
Country | Link |
---|---|
EP (1) | EP0282699B1 (en) |
JP (1) | JPH0672013B2 (en) |
CN (1) | CN1010402B (en) |
AT (1) | ATE86950T1 (en) |
AU (1) | AU594229B2 (en) |
CA (1) | CA1298962C (en) |
DE (3) | DE3708781A1 (en) |
DK (1) | DK172441B1 (en) |
ES (1) | ES2039001T3 (en) |
FI (1) | FI84168C (en) |
MY (1) | MY100781A (en) |
NO (1) | NO170575C (en) |
ZA (1) | ZA88539B (en) |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3819451A1 (en) * | 1988-06-08 | 1989-12-14 | Uhde Gmbh | DEVICE FOR CARRYING OUT EXOTHERMAL, CATALYTIC GAS REACTIONS FOR AMMONIA OR METHANOL SYNTHESIS |
DE102004028200B3 (en) | 2004-05-28 | 2005-12-15 | Hippweb E.K. | Method for carrying out heterogeneous catalytic exothermic gas phase reactions for the synthesis of methanol |
DE102006061847A1 (en) * | 2006-12-21 | 2008-06-26 | Uhde Gmbh | Ammonia converter comprises a radially flowed-through catalyst bed, which concentrically surrounds a heat exchanger, an external- and/or an internal annular space and a main flow direction formed by the catalyst bed |
GB201308428D0 (en) * | 2013-05-10 | 2013-06-19 | Johnson Matthey Plc | Reactor |
DE102016203753A1 (en) * | 2016-03-08 | 2017-09-14 | Thyssenkrupp Ag | Process for the production of products under changing load conditions |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
NL6904757A (en) * | 1968-03-28 | 1969-09-30 | ||
IT1041778B (en) * | 1975-07-15 | 1980-01-10 | Snam Progetti | RADIAL FLOW REACTOR FOR AMMONIA SYNTHESIS WITH HIGH THERMAL LEVEL STEAM PRODUCTION |
GB1574723A (en) * | 1976-03-10 | 1980-09-10 | Haldor Topsoe As | Apparatus for the synthesis of ammonia |
IT1141102B (en) * | 1980-11-28 | 1986-10-01 | Ammonia Casale Sa | AXIAL-RADIAL REACTOR FOR HETEROGENEOUS SYNTHESIS |
US4452760A (en) * | 1982-01-18 | 1984-06-05 | The M. W. Kellogg Company | Horizontal ammonia converter |
-
1987
- 1987-03-18 DE DE19873708781 patent/DE3708781A1/en active Granted
- 1987-03-18 DE DE8717724U patent/DE8717724U1/en not_active Expired
-
1988
- 1988-01-22 AT AT88100898T patent/ATE86950T1/en not_active IP Right Cessation
- 1988-01-22 EP EP88100898A patent/EP0282699B1/en not_active Expired - Lifetime
- 1988-01-22 DE DE8888100898T patent/DE3879241D1/en not_active Expired - Fee Related
- 1988-01-22 ES ES198888100898T patent/ES2039001T3/en not_active Expired - Lifetime
- 1988-01-27 ZA ZA880539A patent/ZA88539B/en unknown
- 1988-01-28 CA CA000557528A patent/CA1298962C/en not_active Expired - Fee Related
- 1988-02-01 FI FI880450A patent/FI84168C/en not_active IP Right Cessation
- 1988-02-01 DK DK198800501A patent/DK172441B1/en not_active IP Right Cessation
- 1988-02-02 MY MYPI88000092A patent/MY100781A/en unknown
- 1988-02-04 AU AU11303/88A patent/AU594229B2/en not_active Ceased
- 1988-02-08 NO NO880535A patent/NO170575C/en unknown
- 1988-02-18 JP JP63034127A patent/JPH0672013B2/en not_active Expired - Fee Related
- 1988-02-25 CN CN88100966A patent/CN1010402B/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
ES2039001T3 (en) | 1993-08-16 |
FI84168B (en) | 1991-07-15 |
AU1130388A (en) | 1988-09-22 |
MY100781A (en) | 1991-02-14 |
DE8717724U1 (en) | 1989-10-05 |
NO170575C (en) | 1992-11-04 |
DE3708781A1 (en) | 1988-09-29 |
DK50188D0 (en) | 1988-02-01 |
FI84168C (en) | 1991-10-25 |
NO880535L (en) | 1988-09-19 |
ATE86950T1 (en) | 1993-04-15 |
JPH0672013B2 (en) | 1994-09-14 |
FI880450A0 (en) | 1988-02-01 |
EP0282699A2 (en) | 1988-09-21 |
JPS63230517A (en) | 1988-09-27 |
CN88100966A (en) | 1988-10-05 |
DK50188A (en) | 1988-09-19 |
DE3879241D1 (en) | 1993-04-22 |
FI880450A (en) | 1988-09-19 |
ZA88539B (en) | 1988-07-27 |
AU594229B2 (en) | 1990-03-01 |
CA1298962C (en) | 1992-04-21 |
DK172441B1 (en) | 1998-07-13 |
NO880535D0 (en) | 1988-02-08 |
EP0282699A3 (en) | 1989-04-26 |
EP0282699B1 (en) | 1993-03-17 |
DE3708781C2 (en) | 1989-11-23 |
CN1010402B (en) | 1990-11-14 |
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