1 outline of diesel engine.ppt

7/17/2019 1 Outline of Diesel Engine.ppt

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Copyright 2005 Create Center Co. Ltd.Nissan Diesel Training Center

Automobile EngineeringOutline of Diesel Engine

Contents1. Engine classifications

2. Classifications of reciprocating internal combstion engine

!. "istory of Diesel Engines

#. Comparison of Diesel Engine and $asoline Engine

5. %perating principle of the Diesel Engine&. Combstion in a Diesel Engine

'. Diesel (noc(

). Diesel Engine combstion chambers and their characteristics

*. Engine performance


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Page.Engine[1]Engine Classifications

Combstion

engine

+nternal

Combstion

engine

E,ternal

combstion

engine

-eciprocating

type

-otational

motion type

team

locomoti/e

team trbine

tarling

engine

Diesel engine

$asoline engine

$as trbine

-otary engine

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Page.Engine[1]Engine Classifications

NOTE: A working fluidmeans a fluid thatfunctions as a medium tochange heat into work in acombustion.

Combstion

engine

+nternal

Combstion

engine

E,ternal

combstion

engine

-eciprocating

type

-otational

motion type

team

locomoti/e

team trbine

tarling

engine

Diesel engine

$asoline engine

$as trbine

-otary engine

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Page.Engine

[2]Reciprocating

Internal Combustion Engines1 Classification by +gnition ethod

2 Classification by Combstion ethod Thermodynamic Classification

! Classification by 3el Type and 3el 3eed ethod

# Classification by %peration Techni4e

5 Classification by Cooling ethod& Classification by al/e Type

' Classification by Nmber and 6rrangement of Cylinders

Engines are classified both by number of cylinders and

by the arrangement of cylinders as illustrated on the right!

1" In#line $straight" type 2" %ori&ontal type

'" %ori&ontally opposed type

(" ) type

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Page.Engine[']%istory of Diesel Engines

In 1892, Rudolf Diesel, a German engineer, announced a newt!e of engine in which fuel is in"ected into com!ressed air andignited. This engine came to be known as the diesel engine.

By 1897, diesel engines that used hea# oil as fuel had beende#elo!ed for !ractical use in German. $%ow&s!eed diesel

engine'

Between 1924 and 1926, the de#elo!ment of the in"ection!um! b Robert (osch $from German' led to the de#elo!ment ofhigh&s!eed diesel engines.

In Japan, research and de#elo!ment into diesel engines startedaround in )*+. ( )*+-, -&clinder air&cooled diesel engines witha total dis!lacement of l had been de#elo!ed and !ut to use.

In 1939, /.)liter,-clinder water&cooled automoti#e dieselengines began to be utili0ed, and diesel engine research andim!ro#ements ha#e been continuall !ursued since then.

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Page.Engine

[4]Operation ;rinciple

of the Diesel Engine(1) Operation of 4-cycle Engine

Inta/e Compression Combustion E+haust

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Page.Engine

[4]Operation ;rinciple

of the Diesel Engine

(2) Valve timing in a 4-cycleEngine

16d/ance opening angle of

the inlet /al/e

2 Delayed closre angle of

the inlet /al/e

! 6d/ance opening angle ofthe e,hast /al/e

# Delayed closre angle of

the e,hast /al/eBottom

deadcenter

Inlet .al.e

closes!

E+haust

.al.e

opens!

Top dead

center

Inlet .al.e

opens!

E+haust

.al.e closes!

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Page.Engine[:]Combustion in a Diesel Engine

1 +gnition lag period

2 3lame propagation

period E,plosi/ecombstion period

! Direct combstionperiod

# 8ost9combstionperiod

Combstion state of engine

8-E:-E

Immediate combustion

after in-ection

3udden combustion

Compression CombustionT.D.C.

+gnitionIn-ection

ends!In-ection

begins.

Ignition lag

C-6N; 6N$LE

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Page.Engine[?]Diesel @noc/

Diesel knock can e prevented y s!ortening t!e ignition lagperiod" #$el in%ection no&&les are generally designed to lo'er

f$el in%ection d$ring t!e ignition lag period" T!e same effect

can e otained y t!e follo'ing met!ods

1" 9sing fuel =ith a high cetane number $cetane inde+"!

2" Raising the temperature in the cylinder! $Raising the

compression pressure!"

'" 9sing the suitable cooling =ater temperature!

(" 9sing the suitable in-ection timing!

4" 9sing suitable fuel in-ection pressure and atomi&ation!

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Page.Engine

[6]Diesel Engine

Combustion and heir Characteristics(1)Direct n%ection Type

Direction of 3el in=ection

$a' $b' $c'

roidal type

he basic shape is a heart

$a' $b' $c'

he basic shape is a semi#sphere

trctre of Direct +n=ection TypeCombstion chambers

No77le Combstion chamber

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Page.Engine

[6]Diesel Engine

Combustion and heir Characteristics(2) *re-com$stion Type


$a' $b' $c' $d'

trctre of 8re9combstion

Chamber Type

No77le

8re9combstion

chamber

ain combstion

chamber

$lo< plg

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Page.Engine

[6]Diesel Engine

Combustion and heir Characteristics(+) ,'irl !amer Type


$a' $b' $c' $d'

trctre of


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Page.Engine[]Engine ;erformance

(1) Brake Tor.$e/ ,!aft 0orsepo'er/ ,pecific #$el om$stion

1 >ra(e tor4e Trning force

3orce ?3@

3orceTor4e

Length

Length ?-@

r

3

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(1) Brake Tor.$e/ ,!aft 0orsepo'er/ ,pecific #$el om$stion

1 >ra(e tor4e Trning force

3orce ?3@

3orceTor4e

Length

Length ?-@

r

3

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Page.Engine

Bor/ ,orce $," Distance of mo.ement $Arc length l"

1 ;3 is the force needed to mo.e a ?4 /g ob-ect 1 m in 1 second!

1 ;3 ?4 /gm0sec

herefore horsepo=er =or/ and torue are related and can be e+pressed by the

follo=ing formulasF

$1" Gra/e torue ,orce Arm length , R R0,

$2" Bor/ B ,orce H 8o.ed distance $Arc length" , l

$'" , 2

Rn $(" Bor/ B 2n

?1 horsepo


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Page.Engine[9]Engine Performance[9]Engine Performance

2 haft force pora(e horsepora(e pots>ts(ilo


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(2) T!ermal Efficiency and ec!anical Efficiency

Theoretical

thermal efficiency

Theoretical

Thermal efficiency

+ndicated thermal

efficiency

6ctalthermal efficiency >ra(ethermal efficiency

(+) ean Effective *ress$re and ndicated 0orsepo'er

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(4) osses and 0eat Balance

1 "eat Loss

2 3riction Loss 8mping loss echanical loss

! "eat >alance

Effecti/e ra(e horsepo


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Page.EngineComparison of EnergyComparison of Energy

EciencyEciency

Page.---

-efining

Transport

torage

pply

Combstion

in Engine

-nning

efficiency

Comparison of energy efficiency

Diesel 2#

$asoline 1*

3el cell 2&

DE 1*


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(3) ir intake and Vol$metric Efficiency

1 olmetric efficiency and charging efficiency

)olumetric efficiency FBeight of actual air inta/e at ; and

Beight of air occupying cylinder .olume at ; and 2 8ercentage of e,cess air

T!e degree of e5cess air is called t!e 6percentage of e5cess air7and can e

e5pressed y t!e follo'ing form$la

;ercentage ofe+cess air

Beight of actual air inta/e

heoretical =eight of air needed for completecombustion of in-ected fuel

Beight of actual air inta/e

Beight of in-ected fuel 1(!2

F

F

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(3) ir intake and Vol$metric Efficiency

! percharging and sperchargers

Dri/en rotor

Dri/e rotor

To

Cylinder

3rom

6ircleaner

Compressor

hosing

Compressor

impeller Trbine hosing

E5!a$st gas

ntake

E,hast

trbine

E,hast

manifold

+nta(e

manifold8oot9s Blo'er ,$perc!arger

E5!a$st T$roc!arger

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(:) Engine performance Testing et!ods

1 Load test

2 inimm idling speed test

! a,imm speed go/ernor performance# tarting test

5 6cceleration test

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(;) Engine performance $rves

1 3ll load performance cr/e

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(;) Engine performance $rves

2 E4al specific fel

consmption cr/es

! 3ish hoo( cr/e

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Page.Engine

1 outline of diesel engine.ppt

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