SE190831C1

SE190831C1 -

Info

Publication number: SE190831C1
Authority: SE
Publication date: 1964-01-01

Description

Prioritet begard frcin den 21,juli 1959 (USA) Ftireliggande uppfinning hanfor sig till en kylfoderanordning for i en reaktionsmotor anordnad brannkammare, exempelvis i en efterforbranningsapparat av avaneerad konstruktion, avsedd for extremt hoga arbetstemperaturer. The present invention relates to a cooling feed device for a fire chamber arranged in a reaction engine, for example in an afterburner of advanced construction, intended for extremely high operating temperatures.

Ett kylfoder kommer ofta till anvandning i en reaktionsmotors efterforbranningsapparat syfte att reducera temperaturen hos dermas barande ytterholje till en riskfri niva. Ett kylfoder har formen av ett generellt cylindriskt organ, som i efterbrannkammaren är placerat som en ringformigt sluten enhet koneentriskt med det barande ytterholjet och pa nagot avstand innanfor detta. Fodret begransar det barande ytferholjets temp eratur genom att avskara varmestralningen fran forbranningsgasen och hindra denna gas fran att komma i direkt berering med ytterholjet. Hittills har man anvant tva olika typer av kylfoder, namligen konvektionskylda foder och spolgaskylda foder. I hada fallen avledes en del av gasflodet fran turbinen och anyandes som kylmedel eller kylgas mellan det barande ytterhOljet och kylfodref. Vid det konvektionskylda fodret ãr det endast kylgasflodet over ytterhOljets och fodrets mot varandra vanda ytor som utnyttjas for kylningen. Vid spolgaskylda foder aro serier av jalusiOppningar eller kontinuerliga springor anordnade med mellanrum utefter fodrets langd. Vid dessa foder utnyttjar man tryekfallet mellan fodrets bada sidor till att injicera en del av kylgasflodet genom jalusioppningarna eller springorna i fodret. Darigenom bildas ett mer eller mindre sarnmanhangande skikt av kylgas over insidan av fodret, dvs. mellan fodret och forbranningsgasen. Hittills ha de for tillverkning av kylfoder tillgangliga materialen varit i stand att raja tryckfallet mellan fodrets hada sidor vid de Dupl. kl. 46 f: 4/02; 46 f: 7/03; 46 g: 7/0 temperaturer, som forekomma i konventionella efterforbranningsapparater. I sadana apparater av mera avancerad konstruktion ha daremot temperaturerna vid vissa drifttillstand stegrats till sidana varden, att konventionella foder av hittills kanda material icke aro i stand att tala de kornbinerade temperaturer och tryck, som uppsta. Resultatet harav har blivit, att prestationsformagan for avancerade efterforbranningsapparater mast avsevart begransas som foljd av bristen pa lampliga kylfoderkonstruktioner. A cooling liner is often used in a reaction engine afterburning apparatus for the purpose of reducing the temperature of its bearing outer casing to a risk-free level. A cooling liner is in the form of a generally cylindrical member, which in the afterburning chamber is placed as an annular closed unit contiguous with the bearing outer casing and at some distance within it. The liner limits the temperature of the bearing surface casing by cutting off the heat radiation from the combustion gas and preventing this gas from coming into direct contact with the outer casing. So far, two different types of cooling feed have been used, namely convection-cooled feed and flush-gas-fed feed. In all cases, part of the gas flow is diverted from the turbine and otherwise as coolant or cooling gas between the bearing outer casing and the cooling feed ref. In the case of convection-cooled lining, only the cooling gas flow over the surfaces of the outer casing and the lining is used for cooling. In the case of rinsing gas due to rinsing, there are series of blind openings or continuous gaps arranged at intervals along the length of the lining. In these liners, the pressure drop between the two sides of the liner is used to inject a part of the cooling gas flow through the louver openings or slots in the liner. As a result, a more or less cohesive layer of cooling gas is formed over the inside of the feed, i.e. between the feed and the combustion gas. Hitherto, the materials available for the manufacture of cooling lining have been able to trace the pressure drop between the hated sides of the lining at the Dupl. at 46 f: 4/02; 46 f: 7/03; 46 g: 7/0 temperatures, which occur in conventional afterburners. In such apparatus of more advanced construction, on the other hand, the temperatures at certain operating conditions have risen to the side values that conventional liners of hitherto known materials are not able to speak to the grain-bound temperatures and pressures which arise. The result has been that the performance of advanced afterburners must be considerably limited as a result of the lack of suitable coolant constructions.

Uppfinningen har till andamal att astadkomma en forbattrad kylfoderanordning av den typ, som besta'r av ett antal varandra delvis overlappande, ringformiga foderelement, vilka under bildande av ett sasom en primar kylmedelkanal tjanande mellanrum uppbaras i ett ytterholje, samt av inuti foderelementen anordnade och med dessa koneentriska, ringformiga skarmelement, vilka ha huvudsakligen samma axiella utstrackning som foderelementen och tillsammans med dessa bilda sekundara kylmedelkanaler. Kylfoderanordningen enligt uppfinningen kannetecknas i huvudsak darav, att varje skarmelement utgores av ett flertal varandra i perifer led delvis overlappande, bagformiga segment, vilka uppvisa utskjutande vinkelbockade flansar resp. fastoron, anordnade att stodjande uppbara segmenten pa avstand fran foderelementen, varjamte skarmsegmenten och foderelementen aro fast forbundna med varandra medelst nitar, vilka var och en passera genom, i tur och ordning, ett fastora pa nedstromsanden av ett skarmsegment, ett foderelements nedstroms riktade kantparti, ett skarmsegments uppstroms riktade kantparti samt nastfoljande foderelements uppstroms riktade kantparti. 2— — En som exempel vald utfOringsform av uppfinningen skall i det foljande beskrivas i anslutning till bifogade ritning: Pd denna visor fig. 1 schematiskt i axialsnitt en anordning enligt uppfinningen installerad i en reaktionsmotors uttoppsror; fig. 2 visar i axialsnitt och i stone skala en del av det skarmade kylfodret enligt fig. 1; fig. 3 visar i perspektiv en del av ett skarmat kylfoder enligt uppfinningen, och fig. 4 och 5 visa i perspektiv ett par i anordningen enligt fig. 3 ingaende skarmsegment. The object of the invention is to provide an improved cooling lining device of the type, which consists of a number of mutually overlapping, annular lining elements, which during formation of a space serving as a primary coolant channel are supported in an outer casing, and of the lining elements arranged and with these concentric, annular frame elements, which have substantially the same axial extent as the lining elements and together with them form secondary coolant channels. The cooling lining device according to the invention can be characterized mainly in that each frame element consists of a plurality of mutually overlapping, rear-shaped segments, which have projecting angularly bent flanges resp. fasteners, arranged to support the segments standing at a distance from the liner elements, the screen segments and the liner elements being fixedly connected to each other by means of rivets, each of which passes, in turn, a fastener on the downstream edge of a screen segment, a downwardly directed edge portion of a liner member, the upwardly directed edge portion of a screen segment and the upwardly directed edge portion of the next lining element. An exemplary embodiment of the invention will be described in the following in connection with the accompanying drawing: In this illustration, Fig. 1 shows diagrammatically in axial section a device according to the invention installed in a top tube of a reaction engine; Fig. 2 shows in axial section and on a stone scale a part of the shielded cooling lining according to Fig. 1; Fig. 3 shows in perspective a part of a shielded cooling lining according to the invention, and Figs. 4 and 5 show in perspective a pair of shield segments not included in the device according to Fig. 3.

I fig. 1 ãr en reaktionsmotors utloppsror betecknat med 11. Ett skarmat kylfoder 12 enligt uppfinningen dr monterat i utloppsroret. Detta kylfoder innefattar en skarmad del 13, som omger sjalva forbranningsrummet, och en oskarmad del 14, som stracker sig framat (uppstroms) fran forbranningsrummet for upptagande av en strom av kylgas. In Fig. 1, the outlet pipes of a reaction engine are denoted by 11. A shielded cooling liner 12 according to the invention is mounted in the outlet pipe. This cooling liner comprises a shielded part 13, which surrounds the combustion chamber itself, and an unshielded part 14, which extends forward (upstream) from the combustion chamber for receiving a stream of cooling gas.

Sasom framgar av fig. 2, är fodret upphangt i utloppsroret med hjalp av fasten 15 av vinkelbockad plat. Fodret ar av konstruktionen med kontinuerliga utloppsspringor och dr uppbyggt av ett antal generellt cylindriska band 16, anordnade i en serie axiellt efter varandra med bakre kantpartiet av varje band Lverlappat av det framre andpartiet av i stromningsriktningen narmast efterfoljande band. Angransande bands overlappande kantpartier aro sammanfogade pd med mellanrum kring fodrets omkrets fordelade punkter. -MeIlan vardera tara narbelagna sadana fastpunkter aro kantpartierna belagna pd nagot avstand frail varandra, sa att det mellan dem bildas kylgasspringor 17. En latt stralskyddsskarm 18 av tunt material ar fast vid vart och ett av banden 16 i narheten av deltas framre och bakre kanter och stracker sig utefter ban-(lets hela friliggande bredd i axialled. Varje stralskyddsskarm är utefter det tillhorande bandets hela axiella bredd belagen pd nagot avstand fran bandet, sa att det mellan desamma Midas en kylgaskanal 19. Sasom framgar av fig. 2, kunna de overlappande kantpartierna av angransande band och de overlappande kantpartierna av dessas tillhorande skarmar vara sammanfogade med hjalp av enkla nitar '21 i en och sarnma nitkrans. Aerodynamiska pakanningar ph skarmarna undvikas i for al-la praktiska andarnal erforderlig utstrackDing, genom att samtliga skarmar Napa i hu-vudsak parallellt med strommarna av kylgas och forbranningsgas. Tryckfallet Over skarmen blir reducerat till praktiskt taget noll, varfor skarmen verkar som separeringsorgan men icke som tryckupptagande organ eller ehallar e. As can be seen from Fig. 2, the liner is suspended in the outlet pipe by means of the fastened 15 of angled bent plate. The liner is of the construction with continuous outlet slots and is made up of a number of generally cylindrical bands 16, arranged in a series axially one after the other with the rear edge portion of each band overlapped by the front end portion of bands following in the direction of flow. Adjacent edge overlapping edge portions are joined at spaced points around the circumference of the liner. Between each of them adjacent such fixed points the edge portions are spaced at some distance from each other, so that cooling gas gaps 17 are formed between them. A light jet shield 18 of thin material is fixed to each of the bands 16 near the front and rear edges of the delta and extends along the entire exposed width of the track in the axial direction. Each radiation shield is covered along the entire axial width of the associated belt at some distance from the belt, so that between them the same Midas a cooling gas duct 19. As can be seen from Fig. 2, the overlapping the edge portions of adjacent bands and the overlapping edge portions of their associated screens are joined together by means of simple rivets '21 in one and the same rivet ring. substantially parallel to the streams of cooling gas and combustion gas.The pressure drop across the screen is reduced to practical taken zero, for which reason the screen acts as a separating means but not as a pressure-absorbing means or eels e.

Sasom visas i fig. 3, aro fodrets band 16 kontinuerliga, medan skarmarna 18 bildas av -vardera ett flertal bagformiga segment, som Tart far sig aro fastsatta vid fodrets band. Skarmsegmenten aro av tad olika typer 22 och 23, vilka aro sammanfogade vaxelvis till en sluten skarmring. Segmentet 22 ar gene-relit kvadratiskt och har ett par motsatt riktade flansar 24 °eh 25, som stracka sig langs ett mittparti av var sin av segmentets bada sidokanter. Flansarnas 24 och 25 fria kanter aro belagna pa nagot avstand frau segmentets plan och lopa i huvudsak parallellt med detta. Segmentet 22 är ocksa forsett med ett par urtag 26 och 27 i var sitt av dess hada nedstroms belagna Urn. Varje segments 22 framre kantparti stoder mot utsidan av ett av fodrets band 16 i omradet for dettas bakre kant, medan flansarna 21 och 25 vila pa insidan av narmast efterfoljande band 16 av fodret. Segmentet 23 dr generellt rektangulart och utformat med tara. fastoron 28 och 29, sorra stracka sig i sidled i inbordes motsatta riktningar invid segmentets bakre kant. Fastoronen 28 och 29 aro utbockade ur segmentets huvudplan och avsedda att fastas vid ett i fodret ingaende band 16. For att bygga upp en skarmring anbringas segment 23 mellan angransande segment 22 pa sadant salt, att deras sidokanter overlappa segmentens 22 sidokanter. Fastoronen 28 och 29 fastas darefter vid foderbandets 16 bakre kantparti thorn. urtagen 26 och 27 pa segmenten 22. I sammansalt skick stodja segmentens 22 och 23 frarnre kantpartier mot utsidan av samma foderband 16, medan flansarna 24, 25 och fastoronen 28, 29 stodja mot insidan av narmast efterfoljande band 16. Genom detta arrangemang kan minsta mOjliga antal nitar anvandas for sammanfogning av fodrets band och skarmringarnas segment. Salunda galler exempelvis, att varje nit passerar genom ena fa.storat pa ett segment 23, det overlappade kantpartiet av ett av fodrets band 16, det framre kantpartiet av ett segment 22 och det overlappande kantpartiet av narmast efterfoljande bandet 16 av fodret. Vid denna konstruktion ar varje skarmsegment fast vid ett band 16 endast vid sin ena kant och kan darf Or latt bytas ut utan ruhbande av angransande segment, for vilket andamal man endast beh8ver avlagsna tva narbelagna nitar. Varmespanningar i skarmen undvikas genom att man anvander relativt sma segment. Genom att segmenten aro sma., sprides varmet sna.bbt Over hela segmentet och kommer icke att kunna koncentreras inom flagon bestamd del darav, sasom fallet skulle vara, om skarmen yore utford i ett stycke. As shown in Fig. 3, the straps 16 of the liner are continuous, while the screens 18 are each formed by a plurality of bag-shaped segments, which Tart is attached to the straps of the liner. The screen segments are of tad different types 22 and 23, which are joined alternately to a closed screen ring. The segment 22 is generally square and has a pair of oppositely directed flanges 24 ° and 25 °, which extend along a central portion of each of the two side edges of the segment. The free edges of the flanges 24 and 25 are coated at some distance from the plane of the segment and run substantially parallel to it. The segment 22 is also provided with a pair of recesses 26 and 27 in each of its had downstream coated urns. The leading edge portion of each segment 22 abuts the outside of one of the straps 16 of the liner in the region of its trailing edge, while the flanges 21 and 25 rest on the inside of the nearest subsequent strap 16 of the liner. The segment 23 is generally rectangular and designed with kelp. fastoron 28 and 29, sorra extend laterally in opposite directions inboard next to the trailing edge of the segment. The fasteners 28 and 29 are bent out of the main plane of the segment and are intended to be attached to a belt 16 entering the liner. To build up a shield ring, segments 23 between adjacent segments 22 are applied to such salt that their side edges overlap the side edges of the segments 22. The fasteners 28 and 29 are then fastened to the rear edge portion of the conveyor belt 16 thorn. recesses 26 and 27 on the segments 22. In the assembled condition, the outer edge portions of the segments 22 and 23 stand against the outside of the same liner 16, while the flanges 24, 25 and the fastenon 28, 29 support the inside of the nearest subsequent straps 16. Through this arrangement, the smallest possible number of rivets are used to join the lining of the lining and the segment of the shield rings. For example, each rivet passes through one facet of a segment 23, the overlapping edge portion of one of the liner bands 16, the leading edge portion of a segment 22 and the overlapping edge portion of the nearest subsequent band 16 of the liner. In this construction, each screen segment is fixed to a band 16 only at its one edge and can be easily replaced without disturbing adjacent segments, for which purpose only two adjacent coated rivets need be removed. Thermal stresses in the screen are avoided by using relatively small segments. Because the segments are small, the heat is spread rapidly throughout the segment and will not be able to be concentrated within a certain part thereof, as would be the case if the screen were challenged in one piece.

I drift strommar kylgas i axialled i mellanrummet mellan fodret och utloppsrorets omgivande vagg. En del av kylgasen strommar in i oppningarna 17 och armed in i mellanrummen 19 mellan stralskarmarna och fodrets ringformiga band 16. Denna kylgas strommar dfirefter in i forbranningsrummet genom de halal mynnande springorna mellan skarmarna och banden 16 och fortsatter bak- och bildar ett kylgasskikt intill insidan av — —3 narmast efterfoljande skarmringar. Det fran forbranningsgaserna radiellt utstralande varmet upptages av stralskyddsskarmen och kommer icke i beroring med vare sig fodrets band 16 eller utloppsrorets vagg. Det av strâlskärmen upptagna varmet upptages av kylgasstrommen genom mellanrummen 19, sa att endast en ringa del darav upptages av fodrets band 16. Da fodrets utsida kyles konvektivt av den kylgas, som strommar mellan fodret och utloppsrorets vagg, kommer foga, om ens nagot, av det av fodret upptagna varmet att overfOras till denna vagg. Utloppsrorets vagg kommer foljaktligen att utsattas endast for kylgasens varme. In operation, cooling gas flows in the axial direction in the space between the liner and the surrounding cradle of the outlet pipe. Some of the cooling gas flows into the openings 17 and is armed into the gaps 19 between the jet arms and the annular belt of the liner 16. This cooling gas then flows into the combustion chamber through the halal-opening gaps between the bars and the belts 16 and continues behind and forms a cooling gas layer adjacent the inside. of - —3 nearest subsequent screen rings. The heat radiating from the combustion gases is absorbed by the radiation shield and does not come into contact with either the belt 16 of the liner or the cradle of the outlet pipe. The heat absorbed by the radiation shield is absorbed by the cooling gas stream through the gaps 19, so that only a small part of it is absorbed by the liner band 16. As the outside of the liner is convectively cooled by the cooling gas flowing between the liner and the outlet pipe cradle, if any the heat absorbed by the lining to be transferred to this cradle. Consequently, the cradle of the exhaust pipe will only be exposed to the heat of the cooling gas.

Materialet i stralskyddsskarmningen enligt foreliggande uppfinning kan utan risk utsattas for temperaturer upp till c:a 1100° C, under forutsattning att segmenten aro anbragta pa sadant satt, att vasentligen alla termiska och aerodynamiska pakanningar elimineras. Di skarmarna lake aro barande konstruktionsdelar, kunna de framstallas av mycket latt och tunt material, exempelvis med en godstjocklek av c:a 0,250 mm eller mindre. Vid denna konstruktion utsattes fodret for de relativt 'Aga temperaturerna hos skarmringarna i stallet for de avsevart hogre forbranningstemperaturerna. Detta utforande medger en avsevard Okning av farbranningstemperaturen i efterforbranningsapparaten liksom liven av turbinens utloppstemperatur, samtidigt som man kan erna en avsevard minskning av sjalva fodrets drifttemperatur. Vid utforda pray och vid normal korning av motorn bar det visat sig, att de ringar eller band, varav fodret är sammansatt, uppvisat endast c:a 11-17° hogre temperatur an turbinens utloppsgaser. Under dessa forhallanden kommer det barande ytterholjet, dvs. utloppsriiret, att avge mera varme an det tillf3res fran fodret. Da fodret och ytterholjet salunda arbeta vid minskade temperaturer, kunna de tillverkas av lattare och billigare material. Man uppnar salunda bade vikt- och kostnadsbesparingar i samband med efterforbranningsapparatens konstruktion. The material of the radiation shielding shield according to the present invention can be exposed without risk to temperatures up to about 1100 ° C, provided that the segments are arranged in such a way that substantially all thermal and aerodynamic packings are eliminated. The screens are load-bearing structural parts, they can be made of very light and thin material, for example with a wall thickness of about 0.250 mm or less. In this construction, the feed is exposed to the relatively'ga temperatures of the screen rings instead of the significantly higher combustion temperatures. This design allows a significant increase in the combustion temperature in the afterburner as well as the life of the turbine outlet temperature, while at the same time a significant reduction in the operating temperature of the feed itself can be achieved. During challenge and during normal running of the engine, it was found that the rings or belts, of which the feed is composed, showed only about 11-17 ° higher temperature than the turbine's exhaust gases. Under these conditions comes the bearing outer shell, i.e. the outlet pipe, to emit more heat than is supplied from the feed. Since the lining and the outer casing thus work at reduced temperatures, they can be made of lighter and cheaper materials. Thus, both weight and cost savings are achieved in connection with the design of the afterburner.

Det skarmade fodret enligt uppfinningen har visserligen liar beskrivits och askadlig glorts endast med tillampning pa en efterforbranningsapparat, men det ligger givetvis inom uppfinningstankens ram att tillampa uppfinningen mom vane omrade med hogintensiv forbranning, t. ex. paen ringformig brannkammare for reaktionsmotorer.Although the shielded lining according to the invention has been described and injected only with application to a post-combustion apparatus, it is of course within the scope of the inventive idea to apply the invention in the field of high-intensity combustion, e.g. on annular combustion chambers for reaction engines.

Claims

Claim claim: Cooling feed device for a fire chamber arranged in a reaction engine, for example in a post-combustion apparatus, consisting of a number of mutually overlapping, annular feed elements, which are supported in an outer casing while serving as a primal coolant channel, and of elements inside the feed and with these concentric, annular frame elements, which have substantially the same axial extent as the lining elements and together with them form secondary coolant channels, characterized in that each frame element (18) consists of a plurality of circumferentially partially overlapping, rear-shaped segments (22, 23). ), which have projecting angled bends (24, 25), resp. 'fasteners (28, 29), arranged to support the segments standing at a distance from the lining elements, while the screen segments and the lining elements are fixed to each other by means of rivets, (21), each of which passes through, in turn, a fastor ( 28, 29) on the downstream edge of a screen segment (23), a downwardly directed edge portion of a liner element (16), an upstream directed edge portion of a screen segment (22) and the upwardly directed edge portion of the adjacent liner element (16).