斯特林发动机讲解

1、斯特林发动机斯特林发动机是一种闭循环活塞式热机，闭循环的意思是工作燃气一直保存在气缸内,而开循环则如内燃机和一些蒸气机需要与大气交换气体。斯特林发动机一般被归为外燃机。切图以外的菱形驱动器测试配置斯特林发动机的设计：*粉红-热筒壁*深灰色-冷筒壁（与冷却进排气管在黄色）*暗绿色-热绝缘分开的两个汽缸结束*浅绿色-置换活塞*深蓝色-功率活塞*淡蓝色-曲柄连杆和飞轮没有表明：热源和热汇。在此设计了置换活塞构造没有专门建造的再生。介绍斯特林发动机在热机中的效率目前是最高的，有时可以达到80%。Intheconversionofheatintomechanicalwork,theStirlingeng

2、inehasthepotentialtoachievethehighestefficiencyofanyheatengine.ItcantheoreticallyperformuptothefullCarnotefficiency,althoughnotyetinpractice.Thepracticallimitationsincludethenon-idealpropertiesoftheworkinggas,andmaterialpropertiessuchasfriction,thermalconductivity,tensilestrength,creep,rupturestreng

3、th,andmeltingpoint.TheStirlingenginecanrunonanyheatsource,includingchemical,solar,geothermalandnuclear.TherearemanypossibleimplementationsoftheStirlingengine.Mostfallintothecategoryofreciprocatingpistonengine.Incontrasttointernalcombustionengines,Stirlingengineshavethepotentialtouserenewableheatsour

4、cesmoreeasily,tobequieter,andtobemorereliablewithlowermaintenance.Theyarepreferredforapplicationsthatvaluetheseuniqueadvantages,particularlyifthethecostperunitenergygenerated($/kWh)ismoreimportantthanthecapitalcostperunitpower($/kW).Onthisbasis,Stirlingenginesarecostcompetitiveuptoabout100kW.3Compar

5、edtoaninternalcombustionengineofthesamepowerrating,Stirlingenginescurrentlyhaveahighercapitalcostandareusuallylargerandheavier.Theirlowermaintenancerequirementsmaketheoverallenergycostcomparable.Thethermalefficiencyisalsocomparable(forsmallengines),rangingfrom15%-30%.3Forapplicationssuchasmicro-CHP,

6、aStirlingengineisoftenpreferabletoaninternalcombustionengine.Otherapplicationsincludewaterpumping,space-basedastronautics,andelectricalgenerationfromplentifulenergysourcesthatareincompatiblewiththeinternalcombustionengine,suchassolarenergy,andbiomasssuchasagriculturalwasteandotherwastesuchasdomestic

7、refuse.StirlingshavealsobeenusedasamarineengineinSwedishGotlandclasssubmarines.4HoweverStirlingsaregenerallynotprice-competitiveasanautomobileengine,duetohighcostperunitpower,lowpowerdensityandhighmaterialcosts.Inrecentyears,theadvantagesofStirlingengineshavebecomeincreasinglysignificant,giventheris

8、einliquidfuelpricesandconcernssuchaspeakoilandclimatechange.Stirlingenginesaddresstheseissuesbybeingverycompatiblewithallrenewableenergyandfuelsources.ThesegrowinginterestsinStirlingtechnologyhavefosteredtheongoingresearchanddevelopmentofStirlingdevices,andR&Dbreakthroughshaveinturnincreasedinterest

9、inthetechnology.Ifsuppliedwithmechanicalpower,Stirlingscanfunctioninreverseasaheatpumpforheatingorcooling.ExperimentshavebeenperformedusingwindpowerdrivingaStirlingcycleheatpumpfordomesticheatingandairconditioning.Inthelate1930s,thePhilipsCorporationoftheNetherlandssuccessfullyutilizedtheStirlingcyc

10、leincryogenicapplications.5Basicanalysisisbasedontheclosed-formSchmidtanalysisgoogle翻译:斯特林发动机是一个封闭的循环蓄热式发动机，气体工质。“封闭循环”是指工作流体内永久的发动机。工作流体是气体推动活塞上。这种外部热发动机可以驱动任何热源。“再生”是指利用一个内部换热器称为再生这增加了发动机的热效率相比，类似的，但简单的热斯特林循环的值得注意的是，其完善的理论效率;然而这还没有实现的理想仍然是一项巨大的工程挑战。然而，目前的设计，指出其效率高，操作安静和方便，他们可以利用什么否则将废热。斯特林发动机在目前激动

11、人心的利益为核心的组成部分，国内热电联产（热电联产）单位，这可能产生重大影响全世界的能源消耗。12空军是一个许多可能的气体，可用于在一个斯特林发动机。所谓“热空气引擎”一般用来包含任何热空气引擎的工作液。热空气引擎可以使用任何一个几个不同的热力循环，包括布雷顿循环，爱立信斯特林循环或周期。在斯特林发动机已用于小型低功耗应用了近两个世纪。斯特林发动机继续使用他们的能力提供机械或电力，加热或冷却的应用，热源和散热片可用。斯特林发动机背景NameThoughithadbeensuggestedasearlyas1884thatallclosedcycleairenginesshouldbegener

12、icallycalledStirlingenginesaftertheinventorofthefirstpracticalexample,theideafoundlittlefavourandthevarioustypesonthemarketcontinuedtobeknownbythenameoftheirindividualdesignerormanufacturer.Then,inthe1940s,thePhilipscompanywassearchingforasuitablenameforitsversionoftheairenginewhichbythattimehadalre

13、adybeentestedwithothergases.Rejectingmanysuggestions,includinghotgasengine(gasenginewasalreadyingeneraluseforinternalcombustionenginesrunningongaseousfuels)andexternalcombustionengine(didnotdifferentiatebetweenopenandclosedcycles),PhilipseventuallysettledonStirlingengineinApril1945.Generalacceptance

14、ofthetermfollowedafewyearslater.8EarlyyearsIllustrationtoRobertStirlings1816patentapplicationoftheairenginedesignwhichlatercametobeknownastheStirlingEngine.TheStirlingengine(orStirlingsairengineasitiswasknownatthetime)wasinventedandpatentedbyReverendDr.RobertStirlingin1816.9Itfollowedearlierattempts

15、atmakinganairenginebutwasprobablythefirsttobeputtopracticalusewhenin1818anenginebuiltbyStirlingwasemployedpumpingwaterinaquarry.10ThemainsubjectofStirlingsoriginalpatentwasaheatexchangerwhichhecalledaneconomiserforitsenhancementoffueleconomyinavarietyofapplications.Thepatentalsodescribedindetailthee

16、mploymentofoneformoftheeconomiserinhisuniqueclosed-cycleairenginedesignllinwhichapplicationitisnowgenerallyknownasaregenerator.SubsequentdevelopmentbyRobertStirlingandhisbrotherJames,anengineer,resultedinpatentsforvariousimprovedconfigurationsoftheoriginalengine.Theirpressurisationenhancementhadby18

17、43sufficientlyincreasedpoweroutputenoughtodriveallthemachineryataDundeeironfoundry.12Aswellassavingfuel,theinventorsweremotivatedtocreateasaferalternativetothesteamenginesofthetime,13whoseboilersfrequentlyexplodedcausingmanyinjuriesandfatalities.1415TheneedforStirlingenginestorunatveryhightemperatur

18、estomaximizepowerandefficiencyexposedlimitationsinthematerialsofthedayandthefewenginesthatwerebuiltinthoseearlyyearssufferedunacceptablyfrequentfailures(albeitwithfarlessdisastrousconsequencesthanaboilerexplosion16)-forexample,theDundeefoundryenginewasreplacedbyasteamengineafterthreehotcylinderfailu

19、resinfouryears.17LaternineteenthcenturydevelopmentsSubsequenttothefailureoftheDundeefoundryenginethereisnorecordoftheStirlingbrothershavinganyfurtherinvolvementwithairenginedevelopmentandtheStirlingengineneveragaincompetedwithsteamasanindustrialscalepowersource(steamboilerswerebecomingsafer18andstea

20、menginesmoreefficient,thuspresentinglessofatargettorivalprimemovers).However,fromabout1860smallerenginesoftheStirling/hotairtypewereproducedinsubstantialnumbersfindingapplicationswhereverareliablesourceoflowtomediumpowerwasrequired,suchasraisingwaterorprovidingairforchurchorgans.19Thesegenerallyoper

21、atedatlowertemperaturessoasnottotaxavailablematerials,sowererelativelyinefficient.Buttheirsellingpointwasthat,unlikeasteamengine,theycouldbeoperatedsafelybyanybodycapableofmanagingafire.20Severaltypesremainedinproductionbeyondtheendofthecentury,butapartfromafewminormechanicalimprovementsthedesignoft

22、heStirlingengineingeneralstagnatedduringthisperiod.21TwentiethcenturyrevivalPhilipsMP1002CAStirlinggeneratorof1951DuringtheearlypartofthetwentiethcenturytheroleoftheStirlingengineasadomesticmotor22wasgraduallyusurpedbytheelectricmotorandsmallinternalcombustionenginesuntilbythelate1930sitwaslargelyfo

23、rgotten,onlyproducedfortoysandafewsmallventilatingfans.23AtthistimePhilipswasseekingtoexpandsalesofitsradiosintoareaswhereelectricitywasunavailableandthesupplyofbatteriesuncertain.Philipsmanagementdecidedthatalow-powerportablegeneratorwouldfacilitatesuchsalesandtaskedagroupofengineersatthecompanysre

24、searchlab(theNat.Lab)inEindhoventoevaluatealternatives.AfterasystematiccomparisonofvariousprimemoverstheStirlingenginesquiet(bothaudiblyandintermsofradiointerference)operationandabilitytorunonavarietyofheatsources(commonlampoil-cheapandavailableeverywhere-wasfavoured),theteampickedStirling.24Theywer

25、ealsoawarethat,unlikesteamandinternalcombustionengines,virtuallynoseriousdevelopmentworkhadbeencarriedoutontheStirlingengineformanyyearsandassertedthatmodernmaterialsandknow-howshouldenablegreatimprovements.25Encouragedbytheirfirstexperimentalengine,whichproduced16wattsofshaftpowerfromaboreandstroke

26、of30 x25mm,26Phillipsbeganadevelopmentprogram.ThisworkcontinuedthroughoutWorldWarIIandbythelate1940shandedovertheType10toPhilipssubsidiaryJohandeWittinDordrechttobeproductionisedandincorporatedintoageneratorset.Theresult,ratedat200wattsfromaboreandstrokeof55x27mm,wasdesignatedMP1002CA（knownastheBung

27、alowset）.Productionofaninitialbatchof250beganin1951,butitbecameclearthattheycouldnotbemadeatacompetitivepriceandtheadventoftransistorradioswiththeirmuchlowerpowerrequirementsmeantthattheoriginalrationaleforthesetwasdisappearing.Approximately150ofthesesetswereeventuallyproduced.27Somefoundtheirwayint

28、ouniversityandcollegeengineeringdepartmentsaroundtheworld28givinggenerationsofstudentsavaluableintroductiontotheStirlingengine.PhilipswentontodevelopexperimentalStirlingenginesforawidevarietyofapplicationsandcontinuedtoworkinthefielduntilthelate1970s,butonlyachievedcommercialsuccesswiththereversedSt

29、irlingenginecryocooler.Theydidhowevertakeoutalargenumberofpatentsandamassawealthofinformationwhichtheylicensedtoothercompaniesandwhichformedthebasisofmuchofthedevelopmentworkinthemodernera.29在将热变成机械功的转换上，史特林引擎在真实的热机中可达最高的热效率，至多80%,仅受工作气体和引擎材料的不理想性质限制，例如摩擦、热传导性、抗张强度、缓慢、熔点等。此引擎理论上可用任何足量的热源运行，包括太阳能、化学能

30、和核能。与内燃机相比，史特林引擎往往维修需求较低，更高效、更安静、而且更可靠。它们倾向被应用于某些特殊用途以发扬其独特优点。特别是首要目标非减低每单位功率的投资成本（金钱/千瓦），而是减低引擎产生每单位能量的成本（金钱/度）的时候。在额定功率下，史特林引擎的投资成本目前比内燃机引擎高，而且通常更大更重，因此这引擎科技很少单独以此作为竞争基准。然而在一些用途上,适当的本益分析可令史特林引擎优于内燃机引擎。近年来，鉴于能源成本普遍上涨，能源短缺和气候变迁之类的环境问题，史特林引擎的优点愈来愈显著。对史特林引擎科技提高兴趣促进了史特林装置的研发。其应用涵盖借由不相容于内燃机的丰富能源抽水、宇基太空航

31、行、发电，像是太阳能、农业废料还有家庭垃圾。另一个史特林引擎的潜力是，若供应机械功，它可以作为一种热泵。已有实验利用风能驱动史特林热泵作为家用冷暖空调。斯特林发动机功能描述EngineoperationSincetheStirlingengineisaclosedcycle,itcontainsafixedmassofgascalledtheworkingfluid,mostcommonlyair,hydrogenorhelium.Innormaloperation,theengineissealedandnogasentersorleavestheengine.Novalvesarerequ

32、ired,unlikeothertypesofpistonengines.TheStirlingengine,likemostheat-engines,cyclesthroughfourmainprocesses:cooling,compression,heatingandexpansion.Thisisaccomplishedbymovingthegasbackandforthbetweenhotandcoldheatexchangers,oftenwitharegeneratorbetweentheheaterandcooler.Thehotheatexchangerisinthermal

33、contactwithanexternalheatsource,suchasafuelburner,andthecoldheatexchangerbeinginthermalcontactwithanexternalheatsink,suchasairfins.Achangeingastemperaturewillcauseacorrespondingchangeingaspressure,whilethemotionofthepistoncausesthegastobealternatelyexpandedandcompressed.Thegasfollowsthebehaviordescr

34、ibedbythegaslawswhichdescribehowagasspressure,temperatureandvolumearerelated.Whenthegasisheated,becauseitisinasealedchamber,thepressurerisesandthisthenactsonthepowerpistontoproduceapowerstroke.Whenthegasiscooledthepressuredropsandthismeansthatlessworkneedstobedonebythepistontocompressthegasontheretu

35、rnstroke,thusyieldinganetpoweroutput.Whenonesideofthepistonisopentotheatmosphere,theoperationisslightlydifferent.Asthesealedvolumeofworkinggascomesincontactwiththehotside,itexpands,doingworkonboththepistonandontheatmosphere.Whentheworkinggascontactsthecoldside,itspressuredropsbelowatmosphericpressur

36、eandtheatmospherepushesonthepistonanddoesworkonthegas.Tosummarize,theStirlingengineusesthetemperaturedifferencebetweenitshotendandcoldendtoestablishacycleofafixedmassofgas,heatedandexpanded,andcooledandcompressed,thusconvertingthermalenergyintomechanicalenergy.Thegreaterthetemperaturedifferencebetwe

37、enthehotandcoldsources,thegreaterthethermalefficiency.ThemaximumtheoreticalefficiencyisequivalenttotheCarnotcycle,howevertheefficiencyofrealenginesisonlyafractionofthisvalue,eveninhighlyoptimizedengines.Sterlingenginesmallclear.oggPlayvideoVideoshowingthecompressoranddisplacerofaverysmallStirlingEng

38、ineinactionVerylow-powerengineshavebeenbuiltwhichwillrunonatemperaturedifferenceofaslittleas7C,forexamplebetweenthepalmofahandandthesurroundingair,orbetweenroomtemperatureandmeltingwaterice.303132editPressurizationInmosthighpowerStirlingengines,boththeminimumpressureandmeanpressureoftheworkingfluida

39、reaboveatmosphericpressure.Thisinitialenginepressurizationcanberealizedbyapump,orbyfillingtheenginefromacompressedgastank,orevenjustbysealingtheenginewhenthemeantemperatureislowerthanthemeanoperatingtemperature.Allofthesemethodsincreasethemassofworkingfluidinthethermodynamiccycle.Alloftheheatexchang

40、ersmustbesizedappropriatelytosupplythenecessaryheattransferrates.Iftheheatexchangersarewelldesignedandcansupplytheheatfluxneededforconvectiveheattransfer,thentheenginewillproducepowerinproportiontothemeanpressure,aspredictedbytheWestnumber,andBealenumber.3334Inpractice,themaximumpressureisalsolimite

41、dtothesafepressureofthepressurevessel.LikemostaspectsofStirlingenginedesign,optimizationismultivariate,andoftenhasconflictingrequirements.35editLubricantsandfrictionAStirlingengineandgeneratorsetwith55kWelectricaloutput,forcombinedheatandpowerapplications.Athightemperaturesandpressures,theoxygeninai

42、r-pressurizedcrankcases,orintheworkinggasofhotairengines,cancombinewiththeengineslubricatingoilandexplode.Atleastonepersonhasdiedinsuchanexplosion.36Lubricantscanalsoclogheatexchangers,especiallytheregenerator.Forthesereasons,designersprefernon-lubricated,low-coefficientoffrictionmaterials(suchasRul

43、on(plastic)orgraphite),withlownormal-forcesonthemovingparts,especiallyforslidingseals.Somedesignsavoidslidingsurfacesaltogetherbyusingdiaphragmsforsealedpistons.ThesearesomeofthefactorsthatallowStirlingenginestohavelowermaintenancerequirementsandlongerlifethaninternal-combustionengines.发动机运行由于斯特林发动机

44、是一个封闭的循环，它包含一个固定的大规模的天然气被称为“工作流”，最常见的空气，氢气或氦气。在正常运作，引擎是密封的，没有气体进入或离开发动机。无阀是必要的，不像其他类型的活塞式发动机。在斯特林发动机，最喜欢热引擎，通过4个周期的主要过程：冷却，压缩，加热和扩张。这是通过移动的气体之间来回热冷热交换器，往往与再生之间的加热器和冷却器。热换热器的热与外部的热源，如燃料燃烧器，和冷战式换热器是在接触热与外部散热片，如空气鱼翅。改变气体温度会引起相应的变化，气体压力，而运动的活塞造成的天然气将轮流扩大和压缩。气体的行为如下描述了天然气的法律，说明气体的压力，温度和体积是有关系的。当气体被加热，因为它

45、是在一个密封的房间，压力上升，这对当时行为的权力活塞产生动力中风。当冷却气体的压力下降，这意味着较少的工作需要做的活塞压缩气体返回中风，从而产生了净功率输出。当一方活塞开放的气氛中，操作稍有不同。由于密封货量工作气体接触的热点方面，它的扩大，是做人的工作的活塞和气氛。当工作气体接触冷战一方，其压力低于大气压力的气氛推的活塞和不工作的天然气。总之，使用斯特林发动机的温度差异其热端和冷端建立一个周期的一个固定数量的天然气，加热和扩大，冷却和压缩，从而热能转换为机械能。更大的温度差异的热点和冷源，更大的热效率。最高理论效率相当于卡诺循环,但效率的真正的发动机是只有一小部分的价值，即使是在高度优化的引

46、擎。斯特林引擎小clear.ogg视频显示压缩机和置换的一个非常小的斯特林发动机在行动非常的低功率发动机已建成这将运行在温差只有7C，例如棕榈油之间的手和周围空气之间，或室温和融化水冰。303132加压在大多数高功率斯特林发动机，无论是最低压力和平均压力的工作流体高于大气压力。这一初步增压发动机可实现泵，或填补了发动机的压缩天然气罐，甚至只是发动机密封时的平均温度低于平均温度。所有这些方法提高质量的工作液中的热力循环。所有的换热器的尺寸必须适当提供必要的传热率。如果换热器是精心设计，可供应热通量所需的对流换热，然后将发动机产生电力中所占的比例平均压力，因为预测的一些西方国家和一些比尔。3334

47、在实际上，最大的压力也是有限的安全压力，压力容器。如同大多数方面的斯特林发动机的设计，优化多元，而且往往有矛盾的要求。35润滑油和摩擦斯特林发动机和发电机组55千瓦的电力输出，为热电联产的应用。在高温度和压力，氧气在空气加压曲轴箱，或在工作气体的热空气引擎，可以结合发动机的润滑油和爆炸。至少有一人已死于这种爆炸。36润滑油也可以堵塞换热器，特别是再生。由于这些原因，设计者宁愿不润滑，低摩擦系数材料(如卢伦(塑料)或石墨)，低正常部队的运动部件，尤其是滑动密封。一些设计，避免滑动表面完全采用隔膜密封活塞。这些都是一些因素，使斯特林引擎有较低的维修要求和更长的寿命比内燃机斯特林循环Mainarti

48、cle:StirlingcycleTheidealizedortextbookStirlingcycleisathermodynamiccyclewithtwoisochores(constantvolume)andtwoisotherms(constanttemperature).Itisthemostefficientthermodynamiccyclecapableofpracticalimplementationinanengine-itstheoreticalefficiencyequalingthatofthehypotheticalCarnotcycle.Howeverreal-

49、worldissuesreducetheefficiencyofactualengines,duetolimitsofconvectiveheattransfer,andviscousflow(friction).Therearealsopracticalmechanicalconsiderations,forinstanceasimplekinematiclinkagemaybefavoredoveramorecomplexmechanismneededtoreplicatetheidealizedcycle.主要文章：斯特林循环在理想化或“文字书”斯特林循环是一个热力循环有两个isocho

50、res（恒容）和两个等温线（恒定的温度）。这是最有效的热力循环能够切实执行的引擎-其理论效率相当于这一虚构的卡诺循环。然而现实世界的问题，降低效率，实际的发动机，由于界限的对流换热和粘性流动（摩擦）。也有实际的机械因素，比如一个简单的运动联系起来可能是有一个更复杂的机制需要复制的理想化的周期斯特林改进Mainarticle:RegenerativeheatexchangerInaStirlingengine,theregeneratorisaninternalheatexchangerandtemporaryheatstoreplacedbetweenthehotandcoldspacessu

51、chthattheworkingfluidpassesthroughitfirstinonedirectionthentheother.Itsfunctionistoretainwithinthesystemthatheatwhichwouldotherwisebeexchangedwiththeenvironmentattemperaturesintermediatetothemaximumandminimumcycletemperatures,37thusenablingthethermalefficiencyofthecycletoapproachthelimitingCarnoteff

52、iciencydefinedbythosemaximaandminima.TheprimaryeffectofregenerationinaStirlingengineistogreatlyincreasethethermalefficiencybyrecyclinginternallyheatwhichwouldotherwisepassthroughtheengineirreversibly.Asasecondaryeffect,increasedthermalefficiencypromisesahigherpoweroutputfromagivensetofhotandcoldendh

53、eatexchangers(sinceitisthesewhichusuallylimittheenginesheatthroughput),though,inpracticethisadditionalpowermaynotbefullyrealizedastheadditionaldeadspace(unsweptvolume)andpumpinglossinherentinpracticalregeneratorstendstohavetheoppositeeffect.Theeasiestwaytounderstandtheregenerator,istoseeitasalumpofm

54、atterplacedintheflowpathoftheworkinggasthattheworkinggasheatsandcoolsasitflowsfromonesideofthestirlingenginetotheother.Asthegasleavesthehotsideoftheengine,thenextgoalofthedesigneristocoolthegas.Iftheregeneratormassiscoolatthatpoint,thehotgaswillbecooledslightlybytheregeneratorasitpassesitandthenfurt

55、hercooledwhenthegasgetstotheheatsinkheatexchanger.Theworkingfluidhasthenbeencooledbytwomethods,theregeneratorandthecoldsinkheatexchanger.Thisprocesshaslefttheregeneratorwarm,thatissomeheathasbeenretainedwithintheengineandnotlosttothecoldheatsink.Thefluidmustthenleavethecoldsideoftheengineandthedesig

56、nersgoalistoheatthefluidasmuchaspossible.Thegaspassesthroughthewarmregenerator,whichheatsthegasalittle,andthenthegasgoesontothehotsideoftheenginewhereitheatsupfurther.Asthecoldgasmovedpasttheregeneratoritcooledtheregeneratoralittleleavingitcoolerandreadyforthenextcycle.Theregeneratoristhereforeamass

57、thatisheatedandcooledbetweentheheatsourceandheatsinktemperaturesastheworkingfluidmovesbackandforth.Theregenerator,asaworkingfluidpre-heater,pre-cooler,improvestheabilitytoheatandcooltheworkingfluid.Thisreducestheburdenontheheatsourceandsinkheatexchangersinmovingtheworkingfluidtothemaximumhighandlowt

58、emperatures.Theregeneratorshouldnotlimittheflowoftheworkingfluidasitmovesabouttheengine,anditshouldnotaddadditionalvolumeofworkingfluid,justforthesakeofaddingaregenerator.Designingasuccessfulregeneratorisabalancebetweenhighheattransferwithlowviscouspumpinglossesandlowdeadspace.Theseinherentdesigncon

59、flictsareoneofmanyfactorswhichlimittheefficiencyofpracticalStirlingengines.Atypicaldesignisastackoffinemetalwiremeshes,withlowporositytoreducedeadspace,andwiththewireaxesperpendiculartothegasflowtoreduceconductioninthatdirectionandtomaximizeconvectiveheattransfer.38InanalphaStirlingenginetheregenera

60、torwouldbeplacedintheflowbetweenthehotandcoldcylinders.Inbetaandgammaenginestheregeneratorisusuallyincorporatedintheheadofthedisplacerpiston.Oftenthedisplacerpistonheaditselfactsasalowefficiencyregeneratorwithoutanyadditionaldesignfeatures.TheregeneratoristhekeycomponentinventedbyRobertStirlingandit