Etm 08 Turbocharging

download Etm 08 Turbocharging

of 58

Transcript of Etm 08 Turbocharging

  • 8/6/2019 Etm 08 Turbocharging

    1/58

  • 8/6/2019 Etm 08 Turbocharging

    2/58

    To increase the engine power

    increase the size of the engine (swept volume)

    increase the mass of the air/fuel charge compressedin the cylinders by using a supercharger or a turbocharger .

  • 8/6/2019 Etm 08 Turbocharging

    3/58

    Increase the Engine Size

    To increase the engine size, a greater mass of air/fuel is burnt.

    Higher fuel costs as more fuel is burnt.

    More mechanical losses

    The engine is heavier/larger as the vehicle is carrying more loadand the vehicle needs to be larger to take the engine.

    At high altitudes, insufficient oxygen to burn the fuel, resultingin low power and black smoke.

  • 8/6/2019 Etm 08 Turbocharging

    4/58

    Supercharge

    A supercharger increases the pressure of the air in the inletmanifold of the engine.

    Greater than atmospheric pressure has a higher density i.e. moreoxygen.

    Greater mass of air rushes into the cylinder to be burnt with thefuel. More power is generated at each engine speed.

    But the supercharger is driven by the engine. A supercharger could increase a 200hp engine to a 275hp engine. It needs 50hp tooperate therefore only increases the engine to 225hp.

  • 8/6/2019 Etm 08 Turbocharging

    5/58

    Turbocharge

    A turbocharger acts in a similar way as a supercharger.It pressurises the air at the inlet manifold.

    Greater mass of air is drawn into the cylinder to be burnt with the fuel. More power is generated.

    Unlike the supercharger it is not driven by the engine. It uses the wasteenergy from the exhaust gas to drive a turbine wheel that is linked to thecompressor through a shaft.

    At high altitudes the turbocharger rotates faster to increase delivery of air tothe engine to compensate. So a turbocharger maintains power from theengine and produces clean emissions.

  • 8/6/2019 Etm 08 Turbocharging

    6/58

    Air Intercooler

    Fitting a turbocharger and an air cooler can increase engine

    power even more.

    An Intercooler removes the heat of compression between the

    stages of a compressor whereas an aftercooler reduces thetemperature of the air leaving the compressor.

    Delivering colder air means more oxygen per cylinder (cold air has a higher density than warm air) thus more engine power.

  • 8/6/2019 Etm 08 Turbocharging

    7/58

    To conclude, the benefits of turbocharging

    increased engine power output

    (upto 50% increase)

    improved fuel consumption (improved pressure balance

    across the engine)

    improved emissions

    altitude compensation

  • 8/6/2019 Etm 08 Turbocharging

    8/58

  • 8/6/2019 Etm 08 Turbocharging

    9/58

    Dual entry

  • 8/6/2019 Etm 08 Turbocharging

    10/58

    Dual entry

  • 8/6/2019 Etm 08 Turbocharging

    11/58

    Variable vane unit,

    note servo control

  • 8/6/2019 Etm 08 Turbocharging

    12/58

    Waste gate by-pass

    A wastegate is to allow some of the exhaust to bypass theturbine when the set intake pressure is achieved

  • 8/6/2019 Etm 08 Turbocharging

    13/58

    How it works

  • 8/6/2019 Etm 08 Turbocharging

    14/58

    How it works

  • 8/6/2019 Etm 08 Turbocharging

    15/58

    Gas flow passages

  • 8/6/2019 Etm 08 Turbocharging

    16/58

    Rotor design

  • 8/6/2019 Etm 08 Turbocharging

    17/58

  • 8/6/2019 Etm 08 Turbocharging

    18/58

    Intercooler

  • 8/6/2019 Etm 08 Turbocharging

    19/58

    Transient operation: small A/R ratio (nozzle area over turbine wheeldiameter ) to get good acceleration

    Large loads: compressed pressure may exceed the pressure limit.

    Wastegate bypass is required.

    By altering the geometry of the turbine housing as the engine accelerates,

    the turbine's A/R ratio can be maintained at its optimum. (VGT )

  • 8/6/2019 Etm 08 Turbocharging

    20/58

    Structure and operating principle of VGT

  • 8/6/2019 Etm 08 Turbocharging

    21/58

    Garrett Variable Geometry TurbochargerVane mechanism

  • 8/6/2019 Etm 08 Turbocharging

    22/58

    Fixed nozzle end platesSets side vane clearance

  • 8/6/2019 Etm 08 Turbocharging

    23/58

    The integral designVane positions to ensure maximum efficiency and zero blade stall

  • 8/6/2019 Etm 08 Turbocharging

    24/58

    Efficiency vs. turbine flow

  • 8/6/2019 Etm 08 Turbocharging

    25/58

    Chubby vane design

  • 8/6/2019 Etm 08 Turbocharging

    26/58

    Position of vane in the housingSimple yet efficient design, zero vane cocking.

  • 8/6/2019 Etm 08 Turbocharging

    27/58

    Note the stepper motor and rack and pinion

    mechanism

  • 8/6/2019 Etm 08 Turbocharging

    28/58

    ( )

    ( ) kg kJ T T cwwork turbine

    kg kJ T T cw

    work compressor

    pt

    pc

    / _

    /

    _

    43

    12

    =

    =

    Torque curve shows limits to bmep caused by;

  • 8/6/2019 Etm 08 Turbocharging

    29/58

    Torque curve shows limits to bmep caused by;allowable smoke, cylinder pressure, exhaust

    temperature and turbo rev/min

    b h h f

  • 8/6/2019 Etm 08 Turbocharging

    30/58

    Engine & turbocharger characteristics of a 6 cyl. 2.28 litre swirl chamber IDI diesel engine at full load

    Fuel consumption map for TC & NA versions of IDI 2.38 litre

  • 8/6/2019 Etm 08 Turbocharging

    31/58

    p p

    TC

    NA

    Power increased, fuel consumption decreased with TC

    Torque & bfsc of NA &

  • 8/6/2019 Etm 08 Turbocharging

    32/58

    Torque & bfsc of NA &

    boosted 1.2 litre IDI1=1.2 NA

    2= 1.2, Roots blower

    3= 1.2, Comprex

    4=1.2, TC5= 1.6 NA

  • 8/6/2019 Etm 08 Turbocharging

    33/58

    Performance of medium speed TC after- cooled DI. (a) =V12 (b) = V8

    TC after-cooled DI, fuels with differing sulphur

  • 8/6/2019 Etm 08 Turbocharging

    34/58

    TC after cooled DI, fuels with differing sulphurcontent

    Two stage TC after cooled quiescent-chamber DI.

  • 8/6/2019 Etm 08 Turbocharging

    35/58

    Two stage TC after cooled quiescent chamber DI.Boost ratio = 3, 14 litre

    Comparison of boost pressure between VGT and

  • 8/6/2019 Etm 08 Turbocharging

    36/58

    p pwastegate TC

    Comparison of pumping loss ~ between VGT and

  • 8/6/2019 Etm 08 Turbocharging

    37/58

    wastegate turbocharger (2000rev/min at 2.0 bar

    BMEP)

  • 8/6/2019 Etm 08 Turbocharging

    38/58

  • 8/6/2019 Etm 08 Turbocharging

    39/58

  • 8/6/2019 Etm 08 Turbocharging

    40/58

  • 8/6/2019 Etm 08 Turbocharging

    41/58

  • 8/6/2019 Etm 08 Turbocharging

    42/58

  • 8/6/2019 Etm 08 Turbocharging

    43/58

  • 8/6/2019 Etm 08 Turbocharging

    44/58

  • 8/6/2019 Etm 08 Turbocharging

    45/58

  • 8/6/2019 Etm 08 Turbocharging

    46/58

  • 8/6/2019 Etm 08 Turbocharging

    47/58

    Base calculations are available on the net

  • 8/6/2019 Etm 08 Turbocharging

    48/58

  • 8/6/2019 Etm 08 Turbocharging

    49/58

    Benz map

    Turbocharger compressor performance map

  • 8/6/2019 Etm 08 Turbocharging

    50/58

    TC characteristic, with airflow requirements for engine

  • 8/6/2019 Etm 08 Turbocharging

    51/58

    C c a acte st c, w t a ow equ e e ts o e g esuperimposed with constant TC Speed and efficiency

    lines also shown

  • 8/6/2019 Etm 08 Turbocharging

    52/58

    A very Badly matched

  • 8/6/2019 Etm 08 Turbocharging

    53/58

    compressor !!

  • 8/6/2019 Etm 08 Turbocharging

    54/58

    Torque curve shows limits to bmep caused by;allowable smoke, cylinder pressure, exhaust

  • 8/6/2019 Etm 08 Turbocharging

    55/58

    temperature and turbo rev/min

    Effect of charge air cooling

  • 8/6/2019 Etm 08 Turbocharging

    56/58

    (intercooler)

  • 8/6/2019 Etm 08 Turbocharging

    57/58

    Engine TestingR q i t d fi d b l gi l ti

  • 8/6/2019 Etm 08 Turbocharging

    58/58

    Requirements defined by legislation

    14,40

    0,02

    0,1

    0,15

    0,36

    1,1

    5 7 9

    Euro 0

    Euro 1

    Euro 2

    Euro 3

    Euro Euro4/II 4/I

    2,0 3,50

    US2007

    Year EURO PM NOx1990 0 1,1* 14,41992 1 0,36 91995 2 0,15 7

    2000 3 0,10 52005 4/I 0,02 3,52008 4/II 0,02 2

    2007 US 0,01 0,5

    Year EURO PM NOx1990 0 1,1* 14,41992 1 0,36 91995 2 0,15 7

    2000 3 0,10 52005 4/I 0,02 3,52008 4/II 0,02 2

    2007 US 0,01 0,5

    P a r

    t i c l e

    [ g

    / k W h ]

    NOx [ g/kWh ]

    Development of legislation for Heavy Duty Engines in EuropeDevelopment of legislation for Heavy Duty Engines in Europe