Huygens Christian Huygens (1629-1695) , Netherland 1673 Gun Powder, - - PDF document

םימנידומרת םירוזחמב םישודיח םיסאלק ונרק ,וטוא , לזיד ,ןוטיירב , גנילרטס ןוסניקטאו

פורפ ' רש ןרע

Huygens

Christian Huygens (1629-1695) , Netherland 1673 Gun Powder, 2-S engine

Cugnot

Nicolas Joseph Cugnot (1725-1804) , France 1795 Coal and Steam

Otto

Nicolaus August Otto (1832-1891) , Germany 1867 Gasoline 4-S

Otto

1 2 1

1 1 1

−

− = − =

k v th

r T T η

( ) ( )

2 3 1 4

1 1 T T mc T T mc Q Q Q Q Q

v v H L H L H th

− − − = − = − = η

4 3 1 3 4 1 2 1 1 2

T T V V V V T T

k k

=         =         =

− −

( ) ( )

1 / 1 / 1

2 3 1 4 2 1

− − − = T T T T T T

th

η

Real indicator diagram

Actual vs. Ideal Otto cycle

Slow combustion process Incomplete combustion process Heat losses during combustion and expansion Low cp/ cv ratio Exhaust blow-down Pumping losses

Delay & combustion duration

( )

f T T p p S S

L L

1 . 2 1

18 . 2 16 . ,

−                 =

−

For Stoichiometric mixture:

[ ]

3 / 2 3 / 1

~

−

∆

L b

S N CA θ

[ ]

3 / 2 3 / 1

~

−

∆

L d

S N CA θ

Spark ~0.4m/s for STP

Knocking-1

Self ignition Auto-ignition Detonation

BTC ATC

Correct fuel metering Small and uniform fuel droplets Good mixing Incomplete combustion process (high bsfc and emission)

Actual cycles-3

Alternative fuel / oxidant Low cp/ cv ratio Inlet valve timing Wide ports Pumping losses

Engine losses

Stirling Engine-1

2 3 4 1 2 3 4 p T Q 1 v s QH QL

( ) ( ) ( ) ( ) ( ) ( )

3 1 3 4 3 1 2 1 3 4 3 3 4 3 1 2 1 3 4 3

1 / ln / ln / ln T T V V R T V V R T V V R T s s mT s s mT s s mT Q Q Q

H L H Stirling

− = − = − − − − = − = η

Carnot Stirling

η η =

Wankel Engine-2

Spark Expansion Exhaust Intake Compression

Exhaust Intake

Stirling Engine-2

3 4 2 1

Catalyst Main Drawbacks

Under fuel-rich conditions Poor CO and HC conversion Under fuel-lean conditions Poor NOx conversion Under low temperature Poor conversion efficiency Under high temperature Fast thermal aging Deposits: its efficiency is highly sensitive to deposits Back pressure: Constitutes a high back pressure Recycling is a problematic issue

Diesel

( ) ( )

2 3 1 4

1 1 T T mc T T mc Q Q Q Q Q

p v H L H L H th

− − − = − = − = η ( ) ( )

1 / 1 / 1

2 3 1 4 2 1

− − − = T T c T T c T T

p v th

η 2 3 2 3 2 1

T T V V r and V V r

s v

= = =

k s k s k

r V V r V V V V T T T T T T T T =                 = =

− − 1 2 1 1 4 2 2 3 1 2 2 3 3 4 1 4

( )

1 1 1 1

1

− − − =

− s k s k v th

r k r r η

1000 2000 3000 4000 5000 6000 7000 8000 0.2 0.4 0.6 0.8 1 1.2 Pressure [kPa] V/V

max

Diesel cycle s=const. s=const. r

s=2.2

r

s=3.0

Otto cycle 1/8.5 1/22

1 4 3 2

Turbocharger

Compressor Map