History of IC Engines. History continued. History if internal combustion (IC) engines

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1 Histoy of IC Enges 860 Lenoi s enge a oneted steam enge ombusted natual gas a double atg piston, usg eleti ignition. Effiieny = 5% Intenal ombustion Enges: Histoy, enge types and opeation of & stoe enges D. imal Fenando pimal@eng.fsu.edu : Histoy if tenal ombustion IC enges Histoy ontued Bot poe geneation and efigeation ae usually aomplised by systems tat opeate on a temodynami yle: poe yles and efigeation yles. oe podug deises: enges Refigeation podug deies: efigeatos, ai onditiones and eat pumps. Steam enge 700 extenal ombustion enges 876 Niolaus Otto patented te yle enge, it used gaseous fuel 88 Gottlieb Daimle, an engee fo Daimle, left to o on is on enge. His 889 t ylde V as te fist enge to be podued uantities. Used liuid fuel and Ventui type abueto, enge as named Meedes afte te daugte of is majo distibuto 89 Rudolf Diesel built suessful CI enge i as 6% effiient double te effiieny of any ote enge of its time

2 Classifiation of Enges V Enge Extenal s Intenal lcombustion Spa Ignition SI o Compession Ignition CI Configuation Vale Loation Stoe o Stoe 5 7 Enge Configuations Wanel Rotay iston Enge In Le Automobile Hoizontally Opposed Subau V Automobile Radial Aiaft Opposed iston ansafts geaed togete 6 8

3 Rotay Wanel Enge Basi onsideations te analysis of poe yles Cyles enounteed atual deies ae diffiult to analyze beause of te pesene of ompliatg effets su as fition et. Conside a yle tat esembles te atual yle losely but it made up totally of tenally eesible poess ideal yle l Ref. Intenal ombustion enges and ai pollution, E. F. Obet emal effiieny, t W Q o 9 Idealizations and simplifiations Cyle does not ole any fition: no pessue dop te og fluid. Expansion and ompession poess: uasi euilibium. ipes onnetg aious omponents ae ell sulated. Negletg anges KE and E 0

4 Net o of te yle Ai standad assumption Gas poe yles og fluid gas: spa ignition enges, diesel enges, onentional gas tubes, et. All tese enges enegy is poided by bung a fuel it te system bounday. Wog fluid ai maly ontas nitogen and adly undegog any emial eations te ombustion ambe and an be losely esembles to ai at all times te ambe. Assumptions: og fluid as ai, beaes as ideal gas, tenally eesible yle, ombustion poess eplae by eat addition poess by a extenal soue, exaust poess eplae by eat ejetion poess tat e stoes itial state of og fluid, speifi eat alues detemes at oom tempeatues all old ai standad assumptions. 5 Canot yle e Canot yle is te most effiient yle tat an be exeuted beteen eat a soue and a eat s. Canot L H Intae ale Boe Reipoatg Enges Exaust ale Stoe DC BDC op Dead Cente DC : Uppe most position Bottom Dead Cente BDC : Loe most position Stoe : Lengt of piston tael Boe : Diamete of te ylde Cleaane Volume V : V ee piston is at DC Displaement Volume V d :Sept Volume V max V m Compession Ratio = V max /V m = V BDC /V DC Mean Effetie essue ME : W = ME x Displaement Volume Reipoatg Enge is INERNAL COMBUSION ENGINE, and is Classified to types:. Spa Ignition SI: Gasole Enge, Mixg ai fuel side ylde, ignites by a spa plug Auto yle. Compession Ignition CI: Diesel enge, fuel is jeted to te ylde, self ignited as a esult of ompession Diesel yle. รศ.ดร.สมหมาย ปร เปรม 6

5 ats of an enge Fou Stoe Enge spa ignition enge Intae Compession oe Exaust. Intae Stoe piston moes fom DC to BDC, dag fes ai-fuel mixtue.. Compession Stoe piston moes fom BDC to DC, ompess ai-fuel mixtue.. oe Stoe piston at DC, spa plug ignite te ai-fuel mixtue. te ombustion ou ey fast tat, teoy, te piston still at DC. Afte tat te piston is pused to BDC.. Exaust Stoe piston moes fom BDC to DC, puses te ombustion gases. 7 9 Mean Effetie essue, ME Conept Atual oesses Euialent by ME Atual and ideal yle spa ignition enge Euialent W ME W m max m max DC BDC W = ME x Displaement Volume = ME x V max -V m 8 0 5

6 o Stoe Enge Compession oe Intae & Exaust Enegy balane Otto yle I Negletg anges KE and E u J / g. Compession Stoe piston moes fom BDC to DC, ompess ai fuel mixtue.. oe Stoe piston at DC, spa plug ignite te ai fuel mixtue. Afte te piston is pused to BDC. Meanile, ab talf ay, ombustion gases ae disaged and fes ai fuel mixtue is dag. stoe enges geneally less effiient tan stoe enges se patial expulsion of unbuned mixtue it exaust gas. It as ige poe/eigt atio. Heat tansfe to/fom te system is unde onstant olume no o Otto u u u u Ealuate at oom tem: alled old ai standad assumption s =s s =s = = s Ai Standad Otto Cyle Niolaus A. Otto 876 Ideal yle of spa ignition enge, ompises of - oess: oess - Isentopi Compession piston moes fom BDC to DC oess - = onstant, eat added piston stays still, epesents ombustion oess - Isentopi expansion piston moes fom DC to BDC gies OWER oess - = onstant, eat ejetion piston stays still, epesents EXHAUS and INAKE stoe ee ae only -stoe of all -poesses, Enegy balane Otto yle II Otto oesses and ae isentopi and = and = =onstant s =s s =s s = = s =s s =s s Compession atio V V max m V V DC BDC Wat is te diffeent of Otto yle fom Canot yle, te most effiient yle Otto = = 6

7 emal effiieny of a Otto yle I Otto Hig ompession atios: tempeatue of ai/fuel mixtue ises aboe auto ignition tempeatue pematue ignition podues audible noise is alled enge no. Impoement of temal effiieny as obtaed utilizg ige ompession atios up to gasole blend it tetaetyl lead impog otane atg but it as been poibited to use se te azadous of lead to ealt. =. Otane atg = measue of fuel uality measue of enges no esistane Compession Issues oblems an ou dug a yle if tee is: La of Compession aused fom gasses leag past te piston, a ole te piston, o te tae o exaust ales ae not sealg popely. La of Spa aused by malfuntiong spa plugs, dity spa plugs, mistimed figs, o bad onnetions beteen plugs and te battey. 5 7 emal effiieny of a Otto yle II Most ompession atios ae aound 0:, meang tat te gas let to te ylde is ompessed to /0 times its oigal size. Effiieny is bette it a ige ompession atio but only to te limits of te fuel uality. emal effiieny of atual spa ignition enge ~ 5 0% Monatomi gas He, A =. ai Moleula eigt of te og fluid eases CO etane Ho Fuel is Handled Stutue of Gasole Is mostly ompised of ydoabon moleules ag fom six to ten abon atoms. Otane is a measue of te esistane to detonation. e otane numbe assigned to gasole 87,89, 9, 00,, 0 epesents te atio of eptane, i easily detonates, to isootane, i does not ant to detonate bette to say otane numbe aboe 00 as pefomane numbe. It is alulated by diffeent ay. Often itʹs done by pue extapolation.. Eigty seen otane gasole is gasole tat ontas 87 peent otane and peent eptane o some ote ombation of fuels tat as te same pefomane of te 87/ ombation of otane/eptane

8 Cemial Enegy of Gasole e emial enegy of one gallon of gasole is, on te aeage, 5,000 BU pe gallon 0 6 J pe.8 L. Only ab 5% of emial enegy gasole is oneted to meanial enegy. Basially of a one dolla gallon of gasole, 75 ents is asted. Diesel yle: e ideal yle fo ompession ignition CI enge Rudolp Diesel 890 Simila to spa ignition enge diffeg maly te metod of itiatg ombustion. In spa ignition SI enges gasole enges, ai fuel mixtue ompessed belo auto ignition tempeatue of te ai/fuel mixtue and ombustion stats by fig spa plugs. In ombustion ignition CI enges diesel enges ai ompessed aboe te auto ignition tempeatue of te ai fuel mixtue and ten fuel jet to te ai. SI enges as a abueto and diesel enge as a fuel pump. e ompession atio of diesel enges typially ige 9 Cylde Configuations Diesel enge e fuel jetion stats en te piston eaes to DC. Combustion poess taes plae oe longe teal. Staigt Configuation Flat Configuation V Configuation Displaement efes to te olume side ea piston ambe. Fo example: a.0 Lite enge it 6 yldes ill ae 0.5 lites pe ylde. 0 Beause of tis longe peiod te eat addition poess an be appoximated as onstant pessue eat addition poess. Ote pats ae ommon fo bot SI and CI enges. 8

9 9 Enegy balane Diesel enge I / g J u u u p u u u u Diesel t, Enegy balane Diesel enge II Diesel t, V V Defe ne uantity; utoff atio Utilizg defition of isentopi ideal gas elations Di l, Diesel t is te ompession atio Otto s. Diesel, Diesel t Otto t, Limitg alue of =; en effiienies of bot Otto and Diesel yles ae idential. Diesel yle opeates mu ige ompession atios, teefoe temal effiieny of Diesel enges ae usually ige tan SI enges 5 to 0%. opeate on te same ompession atio en bot yles Diesel t Otto t,, 5 e gi e o % Diesel enges buns fuels moe ompletely tan gasole enges. Enegy ontent of gallon of diesel on aeage, 7,000 BU pe gallon J pe.8 L. Dual yle Moe ealisti ay to model: Combation of eat tansfe Combation of eat tansfe poesses gasole and diesel yles. e elatie amount of eat tansfe dug ea poess an be adjusted to appoximate 6 j pp atual yle moe losely.

10 Bayton Cyle: e ideal yle fo gas tube enges Geoge Bayton 870 Simple Ideal Bayton Cyle Used aiaft populsion and eleti poe geneation. Gas tubes usually opeate on an open yle. Fes ai ambient ondition ompesso tempeatue and pessue aised ombustion ambe fuel bun tube o podue expands to atmospei pessue. Modeled as a losed yle. Ai standad assumptions ae applied. Ai is te og fluid. Hoee, open gas tube yle an be modeled as a losed yle. : isentopi ompession : onstant pessue eat addition : isentopi expansion : onstant pessue eat ejetion 7 9 Open and losed yle gas tube Enegy balane fo steady flo poess J / g p p open yle gas tube losed yle yle gas tube Bayton oesses and ae isentopi, i and = and = Combustion and exaust poesses ae onstant pessue poesses. Exaust popels aft o used to geneate steam. Bayton p essue atio p 8 0 0

11 ypial pessue atios and igest tempeatues Common pessue atios to 6. Higest tempeatue ous at te end of te ombustion poess and limited maximum tempeatue of tube blades an itstand. Fo a fixed let tempeatue, te o put eases it pessue atio, eaes to a maximum alue and ten deeases. Ai/fuel atio aboe 50 is not unommon. Hige ba o usually moe tan one alf of tube o put. =. Gas oe Cyle Jet opulsion enology In jet populsion, gas tube podues little poe and te ig eloity exaust gas esponsible fo podug essay tust fo mog. Adantageous and disadantageous Gas ube Impoements Gas tube enges ae a geat poe to eigt atio ompaed to eipoatg enges. at is, te amount of poe you get of te enge ompaed to te eigt of te enge itself is ey good. Gas tube enges ae smalle tan tei eipoatg ountepats of te same poe. e ma disadantage of gas tubes is tat, ompaed to a eipoatg enge of te same size, tey ae expensie. Beause tey sp at su ig speeds and beause of te ig opeatg tempeatues, designg and manufatug gas tubes is a toug poblem fom bot te engeeg and mateials standpot. Gas tubes also tend to use moe fuel en tey ae idlg, and tey pefe a onstant ate tan a flutuatg load. at maes gas tubes geat fo tgs lie tansontental jet aiaft and poe plants, but explas y you donʹt ae one unde te ood of you a. Inease te gas ombustion tempeatue befoe it entes te tube. Limited by metallugial estition: eami oatg oe te tube blades Impoed teoolg tenology: blo ool ai oe te sufae of te blades film oolg, steam oolg side te blades. Modifiations to te basi temodynami yle: teoolg, eeatg, egeneation Impoe design of tubomaey omponents: multi stage ompesso and tube onfiguation. Bette aeodynami design on blades edue stall.

12 Deiation of atual gas tube yles fom idealized ones. Isentopi effiieny of te ompesso s a s a Isentopi effiieny of te tube a s a s Da diagam 5 7 EXAMLE ROBLEM e pessue atio of an ai standad Bayton yle is.5 and te let onditions to te ompesso ae 00 a and 7C. e tube is limited to a tempeatue of 87C and mass flo is 5 g/s. Deteme a te temal effiieny b te poe put W te BWR ba o atio Assume onstant speifi eats. Stat analysis Let s get te effiieny: p Fom poblem statement, e no p =

13 Net poe put: Net oe: W m m Substitutg fo o tems: W m tub Applyg onstant speifi eats: omp W m p : Solg fo tempeatues: K : 757. K Net poe is ten: W 5 g/ s.005 J / g K K W 0 W 9 5 Need to get and Use isentopi elationsips: p p ; p p and ae non along it te pessue atios: Ba Wo Ratio BWR omp tub Applyg onstant speifi eats: BWR

14 e Bayton yle it egeneation I In gas tube enges te tempeatue of te exausted gas leag te tube is often onsideably ige tan te tempeatue of te ai leag te ompesso. eefoe, ounte flo all egeneato eat exange an be used to aptue potion of eat fom te exaust gas. is impoes te effiieny of te yle. e Bayton yle it egeneation III eefoe, te temal effiieny of Bayton yle it egeneation is depends on mimum/maximum tempeatue atio as ell as pessue atio. Re geneation also most effetie at loe pessues. egen p 5 55 e Bayton yle it egeneation II egen, at egen,max 5 5 ' egen, at egen,max 5 Wit old ai standad assumption patie Unde old ai assumption it egeneation egen p 5