Twin turbo technology

The automobile industry has seen a very rapid growth in the past decade, this is followed by the evolution from ordinary inline cylinder engines to high performance V-type engines, etc., but the parameters which take the centre stage of the competition are efficiency, power, and environmental safety. One technology that is going to be the heart of the future diesel cars is TWIN TURBO technology. The basic principle is derived from the old familiar turbo mechanism. This uses the exhaust from the engine to pressurize the inlet air, thereby providing more oxygen to flow through the combustion chamber, to burn the fuel more efficiently and thus increasing the power output. Unlike the Bi-Turbo mechanism, this Twin Turbo is a combination of two turbo chargers mounted serially rather than in parallel. This configuration offers the car a whopping 112 BHP per litre (1000cc) of engine capacity, which is a world record. And it produces a maximum torque of 400Nm at 1400 RPM. Even though the car delivers a much higher power than its counterparts, it still maintains the conventional 16.5 KMpL as mileage. The environmental safety standard is the major consideration today; this technology is EURO V ready. The only car in India, which has this facility, is Hyundai i20. This technology if properly adopted by the automobile industry could provide a major breakthrough in the Indian commercial car manufacturing.

1. Department of Mechanical
Engineering
K Pavan Kumar,
11781A0347,
IV year, mechanical Dept,
SVCET, Chittoor.
Presented by

2. Twin Turbo Technology

3. Introduction :
Thepoweroutputofanenginedependsupontheamountofairinductedperunittime
andthedegreeofutilizationofthisair,andthethermalefficiencyoftheengine.
IndicatedenginePower
IP=P*L*A*n*K/60000
Where,
IP=indicatedpower(kW)
P=indicatedmeaneffectivepressure(N/m
2
)
L=lengthofstroke
A=areaofpiston
n=noofpowerstroke,for2-sengine-Nandfor4-sengineN/2,N=rpm
K=Noofcylinders

4. Threepossiblemethodsutilizedtoincreasetheair
consumptionofanengineareasfollows:
Increasing the piston displacement: This increases the size and
weight of the engine, and introduces additional cooling
problems.
Running the engine at higher speeds: This results in increased
mechanical friction losses and imposes greater inertia stresses
on engine parts.
Increasing the density of the charge: This allows a greater mass
of the charge to be inducted into the same volume.

5. Definition
Themostefficientmethodofincreasingthepowerofanengineisby
supercharging,i.e.increasingtheflowofairintotheenginetoenable
morefueltobeburnt.
ASuperchargerisrunbythemechanicaldrive,poweredbyenginepower.
Aturbochargerusestheotherwiseunusedenergyintheexhaustgasesto
driveaturbinedirectlyconnectedbyaco-axialshafttoarotary
compressorintheairintakesystem.

6. Introduction :
Theparameterswhichtakethecentrestageofthecompetitionincar
todayareefficiency,power,andenvironmentalsafety.
Onetechnologythatisgoingtobetheheartofthefuturedieselcarsis
TWINTURBOtechnology.
UnliketheBi-Turbomechanism,thisTwinTurboisacombinationof
twoturbochargersmountedseriallyratherthaninparallel.
TheonlycarinIndia,whichhasthisfacility,isHyundaii20.

7. Super Charger

8. Turbo Charger( schematic diagram)

9. Need of turbocharger and super
charger
For ground installations, it is used to produce a gain in the power out
put of the engine.
For aircraft installations, in addition to produce a gain in the power out
put at sea-level, it also enables the engine to maintain a higher power
out put as altitude is increased.

10. Turbo Charger
Aturbochargerispracticallyaturbinethatisfuel-driven.
Aturbocharger,oftencalledaturbo,isasmallradialfanpumpdriven
bytheenergyoftheexhaustflowofanengine.
Aturbochargerconsistsofaturbineandacompressoronasharedaxle.
Theturbochargerincreasesthepressureatthepointwhereairis
enteringthecylinder,agreatermassofair(oxygen)willbeforcedinas
theinletmanifoldpressureincreases.

11. Working principle of a turbocharger:
Aturbochargerisasmallradialfanpumpdrivenbytheenergyofthe
exhaustgasesofanengine.
Aturbochargerconsistsofaturbineandacompressoronashared
shaft.
Theturbineconvertsexhausttorotationalforce,whichisinturnused
todrivethecompressor.
Thecompressordrawsinambientairandpumpsitintotheintake
manifoldatincreasedpressure,resultinginagreatermassofair
enteringthecylindersoneachintakestroke.

12. Where the turbocharger is located in the
car

13. 0
2
3
4
1
Four-stroke cycle of an SI engine equipped with a
supercharger turbocharger, plotted on p-v coordinates.
Thermodynamic analysis of turbocharged engine
cycle

14. NetworkoutputW
net
=workdonebypiston+Gasexchangework
=areaA+area
AreaA=
AreaB=workdonebyturbocharger=
W
net=Workdoneperunitofairmass.
Where,p
0=atmosphericpressure,
p
1=pressureaftercompression,
T
0=atmosphericairtemperature,
V
1=volumeofboostedair,
r
p=pressureratio,
r=compressionratio,cp=Specificheatofair
andη=turbochargerefficiency,

15. Selection process of turbocharger
Illustration of the concept of a turbocharger.
•Compressorairinlet,Point1-p1,T1
•Compressorairoutlet,point2-p2,T2
•Turbineexhaustgasinlet,point3-
p3,T3
•Turbineexhaustgasoutlet-
P4,T4

16. The compressor efficiency = ( theoretical temperature rise across the
compressor)/(the actual temperature rise). e
c is always less than 1.0.
The turbine efficiency = ( the actual temperature drop across the
turbine )/(the theoretical temperature drop). The turbine efficiency is
also always less than 1.0.

17. The mechanical efficiency of the turbocharger

18. Types of Turbo Chargers
SingleTurboCharger
Twin–TurboCharger

19. Single Turbo Charger
SingleTurbo,asingleturbo
requiresall8cylindersin
ordertobuildsomeboost.
Producesgoodresultsfordrag
racing,whichneedsextremely
highpower.

20. Single Turbo Charger
Singleturboenginesareeasier
tosetup.
Therearesuperlargesingle
setupsthatcansupportupto
1500BHP,cancreatereal
powerbutthereisthat
unwantedlag.
Doesn'ttakeupmuchspacein
thecar.

21. Twin-Turbo Charger
Thesecretbehind"twin-turbo"is
theclevertwo-stageforced
aspirationprinciple.
Therevolutionarytwin-turbo
technology,thenextbigstep
forwardinthedevelopmentof
moderndieselenginesfor
passengercars.

22. Twin-Turbo Charger
ThecarwiththeTwin-Turbomechanismgivesmorepower,moretorque,
bettermileage,andacomprehensivepollutionfreeenginethanitsrivals.

23. ENGINE SPEED BELOW 1800 RPM:
Byusingasmallhigh-pressureturbochargerforthefirst
stage,theenginerespondsreadilytothegaspedalatlower
speedswithoutsufferingfrom"turbolag".
Upto1800rpmthishigh-pressureturbochargerworks
aloneandcompressestheintakeairatupto3.2barboost
pressure.

24. ENGINE SPEED BETWEEN 1800 -
3000 RPM:
Between1800and3000rpm,alargerlowpressureturbochargerjoins
in-bothturbinesruntogetherinthisenginespeedrange.
Theexhaustfromthecylinderwilldrivethefirstturbochargerand
cometothesecond.Thiswillleadstotheworkingofthesecondstage
turbochargeritaffectsintheintakeair.Thisintakeairwhichisneeded
forthecombustionissuckedinandgoestothefirststageturbocharger
whichwillpressurizedtheairandgoestothecylinders.

25. ENGINE SPEED ABOVE 3000 RPM:
Above3000rpm,onlythelargerturbochargercontinuestodeliver
chargeairtothecylinders.
Thecomplexcontrolofbothchargersisviaavalveintheengine's
exhaustsystem,controlledbyenginespeedandload.

26. POTENTIAL OF THE TWIN TURBO-
CHARGER
Theenormouspotentialofatwin-turboenginecanbeseen
fromthemeaneffectivepressurevaluesitachieves.
Whereastraditionalturbo-dieselshaveameaneffective
pressureof17to19bars,the1.9-litretwin-turboreaches
26bars.

27. EFFICIENCY:212hpfrom1.9-literenginewithfuelconsumptionofonly6.0
l/100km
Comparedwithanaturallyaspirateddieselengine,poweroutputscan
beraisedbyupto50percentageswithoutincreasingfuelconsumption.
Alternatively,consumptioncanbereducedbyasmuchasaquarter
withoutlossofpower.
Thishigh-techenginedeliversapeakpoweroutputof156kW(212hp)
fromjust1.9littersdisplacement.

28. WiththisenginetheVectraOPCacceleratesfrom0to100in6.5seconds;
thetopspeedisanelectronicallyregulated250km/h.
At6.0littersper100kmintheEuropeantestcycle

29. Vectra OPC

30. TypeofTwin-Turbo
Aftertherevolutionofthetwo-stageturbo-charger,therearetwowaysin
whichtheturbo-chargercanbemounted.Theyareparalleland
sequential.

31. Parallel:

32. Sequential:

33. APPLICATIONS:
Everybodyknowsmechanicalsuperchargersaregoodforlow-endoutputbut
shortofefficiencyathighrev,whileexhaustturbochargersworksstronglyat
highrevbutreluctantlyatlowrev.Fordecadesengineersdreamedof
combiningsuperchargerandturbochargertogether.Thiswastriedoncein
history–the1985LanciaDeltaS4rallycar.

34. 1985 LanciaDelta S4 rally car

35. APPLICATIONS:
In2005,Volkswagenfinallyintroducedaproductionunitto
itsGolf1.4TSI.Called"Twincharger"system.

36. APPLICATIONS:
TheonlycarinIndia,whichhasthisfacility,isHyundaii20.

37. Advantages
Theenvironmentalsafetystandardisthemajorconsiderationtoday,this
technologyisEUROVready.
Eventhoughthecardeliversamuchhigherpowerthanitscounterparts,itstill
maintainstheconventional16.5KMpLasmileage.
At1500rpm,bothchargerscontributeaboutthesameboostpressure,witha
totalof2.5bars.(Iftheturbochargerworksalone,itcanonlyprovide1.3bars
atthesamerev.)
Inthe1.4-litreGolf,theTwinchargersystemproduces170horsepowerand
177lbftoftorque.That'sequivalenttoa2.3-litrenormallyaspiratedengine
butitconsumes20%lessfuel.

38. Advantages
Themoreincreasethepressureoftheintakeairabovethelocalatmospheric
pressure(boost),themorepowertheengineproduces.Automotive
superchargersforstreetusetypicallyproduceamaximumboostpressure
between0.33to1.0bar,providingaproportionateincreaseinpower.
Enginesburnairandfuelatanideal(stoichiometric)ratioofabout14.7:1,
whichmeansthatifyouburnmoreair,youmustalsoburnmorefuel.
Thisisparticularlyusefulathighaltitudes:thinnerairhaslessoxygen,reducing
powerbyaround3%per1,000feetabovesealevel,butasuperchargercan
compensateforthatloss,pressurizingtheintakechargetosomethingcloseto
sealevelpressure.

39. Disadvantages
Cost and complexity
Detonation
Parasitic losses
Space
Turbo lag

40. CONCLUSION:
Fromthis,itisclearthatthevehicle,whichusethis
advancedtechnology,hasprovedtobemoreefficientand
morepowerful.Solet’shopethattherecentautomobilewill
usethistechnologyandgetsmodernized.