Marine Engineering Part1[1]

8/13/2019 Marine Engineering Part1[1]

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Introduction to

Marine Engineering.

D.A. Taylor,MSc, BSc, CENG, FlMarE, FRINA Senior Lecturerin Marine Technology, Hong

Kong olytechnic

Linacre House, Jordan Hill, Oxford 0X2 8DP

PART OF REED ITERATIOAL !OO"#

OXFORD LODO !O#TO

$%I&H E' DELHI #I(APORE #)DE)

TO")O TOROTO 'ELLI(TO

Firs* +ulis-ed ./8 Re+rin*ed ./81

#econd edi*ion .//0 Re+rin*ed .//2

!u**er3or*-4Heine5ann L*d .//0

All ri6-*s reser7ed o +ar* of *-is +ulica*ion 5a9 e re+roduced in an9 5a*erial for5 :includin6 +-o*oco+9in6 or s*orin6

in an9 5ediu5 9 elec*ronic 5eans and 3-e*-er or no* *ransien*l9 or inciden*all9 *o so5e o*-er use of *-is +ulica*ion;3i*-ou* *-e 3ri**en +er5ission of *-e co+9ri6-* -older exce+* in accordance 3i*- *-e +ro7isions of *-e &o+9ri6-*, Desi6ns

and Pa*en*s Ac* ./88 or under *-e *er5s of a licence issued 9 *-e &o+9ri6-* Licensin6 A6enc9 Lid, /0 To**en-a5 &our*

Road London, En6land '.P/HE A++lica*ions for *-e co+9ri6-* -older

Library of Congress Cataloguing in Publication Data

Ta9lor D A

In*roduc*ion *o 5arine en6ineerin6?D,A Ta9lor 4 2nd cd

+ c5

I#! 0 @08 01>0= 8. $arine en6ineerin6 2 $arine 5ac-iner9 I Ti*le

$=00T81 .//0

=2#>4dc20 8/4>.2=

Prin*ed and ound in (rea* !ri*ain 9 *-e %ni7ersi*9 Press &a5rid6e

Preface to second editionProgress has been made in many areas of marine engineering since the first edition of this book was published.

A greater emphasis is now being placed on the cost-effective operation of ships. This has meant more fuel-

efficient engines, less time in port and the need for greater equipment reliability, fewer engineers and more use

of automatically operated machinery.

The marine engineer is still, however, required to understand the working principles, construction and

operation of all the machinery items in a ship. The need for correct and safe operating procedures is as great

as ever. There is considerably more legislation which must be understood and complied with, for example in

relation to the discharging of oil, sewage and even black smoke from the funnel.

The aim of this book is to simply explain the operation of all the ships machinery to an !ngineer

"adet or #unior !ngineer who is embarking on a career at sea. The emphasis is always upon

correct, safe operating procedures and practices at all times. The content has

been maintained at a level to cover the syllabuses of the "lass $ and "lass % !ngineer&s

"ertificates of "ompetency and the first two years of the !ngineer "adet Training 'cheme.

Additional material is included to cover the !ngineering knowledge syllabus of the (aster&s

"ertificate. Anyone with an interest in ships& machinery or a

professional involvement in the shipping business should find this book informative and useful.

). A. Taylor


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Chapter 1

Ships and machinery

As an in*roduc*ion *o 5arine en6ineerin6, 3e 5i6-* reasonal9 e6in 9 *aBin6 an o7erall looB a* *-e s-i+ T-e

7arious du*ies of a 5arine en6ineer all rela*e *o *-e o+era*ion of *-e s-i+ in a safe, reliale, efficien* and econo5ic5anner T-e 5ain +ro+ulsion 5ac-iner9 ins*alled 3ill influence *-e 5ac-iner9 la9ou* and de*er5ine *-e eCui+5en*

and auxiliaries ins*alled T-is 3ill fur*-er de*er5ine *-e o+era*ional and 5ain*enance reCuire5en*s for *-e s-i+ and

*-us *-e Bno3led6e reCuired and *-e du*ies *o e +erfor5ed 9 *-e 5arine en6ineer

Ships

#-i+s are lar6e, co5+lex 7e-icles 3-ic- 5us* e self4sus*ainin6 in *-eir en7iron5en* for lon6 +eriods 3i*- a -i-

de6ree of reliaili*9 A s-i+ is *-e +roduc* of *3o 5ain areas of sBill, *-ose of *-e na7al arc-i*ec* and *-e 5arine

en6ineer T-e na7al arc-i*ec* is concerned 3i*- *-e -ull, i*s cons*ruc*ion, for5, -ai*aili*9 and aili*9 *o endure i*s

en7iron5en* T-e 5arine en6ineer is res+onsile for *-e 7arious s9s*e5s 3-ic- +ro+el and o+era*e *-e s-i+ $ore

s+ecificall9, *-is 5eans *-e 5ac-iner9 reCuired for +ro+ulsion, s*eerin6, anc-orin6 and s-i+ securin6, car6o -andlin6,

air condi*ionin6, +o3er 6enera*ion and i*s dis*riu*ion #o5e o7erla+ in res+onsiili*ies occurs e*3een na7al

arc-i*ec*s and 5arine en6ineers in areas suc- as +ro+eller desi6n, *-e reduc*ion of noise and 7ira*ion in *-e s-i+


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Figure*.* "utawaydrawing of a ship T-e5ore usual +lan and ele7a*ion dra3in6s of a *9+ical slo34s+eed diesel ins*alla*ion are s-o3n in Fi6ure .2

A six4c9linder direc*4dri7e diesel en6ine is s-o3n in *-is 5ac-iner9 arran6e5en* T-e onl9 auxiliaries 7isile are a

diesel 6enera*or on *-e u++er fla* and an air co5+ressor elo3 O*-er auxiliaries 3i*-in *-e 5ac-iner9 s+ace 3ould

include addi*ional 6enera*ors, an oil943a*er se+ara*or, an e7a+ora*or, nu5erous +u5+s and -ea* exc-an6ers An

auxiliar9 oiler and an ex-aus* 6as -ea* exc-an6er 3ould e loca*ed in *-e u+*aBe re6ion leadin6 *o *-e funnel

arious 3orBs-o+s and s*ores and *-e 5ac-iner9 con*rol roo5 3ill also e found on *-e u++er Ha*s

Geared medium-speed diesel

Four 5ediu54s+eed :100 re7?5in; diesels are used in *-e 5ac-iner9 la9ou* of *-e rail ferr9 s-o3n in Fi6ure . T-e

6ear uni*s +ro7ide a *3in4scre3 dri7e a* .>0 re7?5in *o con*rollale4+i*c- +ro+ellers 5e 6ear uni*s also +o3er *aBe4

offs for s-af*4dri7en6enera*ors 3-ic- +ro7ide all +o3er reCuire5en*s 3-ile a* sea

T-e 7arious +u5+s and o*-er auxiliaries are arran6ed a* floor + a*e le7el in *-is 5ini5u54-ei6-* 5ac-iner9

s+ace T-e ex-aus* 6as oilers and u+*aBes are loca*ed +or* and s*aroard a6ains* *-e side s-ell +la*in6

A se+ara*e 6enera*or roo5 -ouses *-ree diesel 6enera*or uni*s, a 3as*e co5us*ion +lan* and o*-er auxiliaries

T-e 5ac-iner9 con*rol roo5 is a* *-e for3ard end of *-is roo5

Steam turbine

T3in cross4co5+ounded s*ea5 *urines are used in *-e 5ac-iner9 la9ou* of *-e con*ainer s-i+, s-o3n in Fi6ure .@

Onl9 +ar* +lans and sec*ions are 6i7en since *-ere is a considerale de6ree of s955e*r9 in *-e la9ou* Eac- *urine

se* dri7es, *-rou6- a doule reduc*ion 6earox 3i*- se+ara*e *-rus* locB, i*s o3n fixed4+i*c- +ro+eller T-e

condensers are loca*ed enea*- eac- lo34+ressure *urine and are arran6ed for scoo+ circula*ion a* full +o3er

o+era*ion and axial +u5+ circula*ion 3-en 5anoeu7rin6

A* *-e floor+la*e le7el around *-e 5ain 5ac-iner9 are loca*ed 7arious 5ain en6ine and s-i+


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T-e 81 5 fla* -ouses a *uro4al*erna*or eac- side and also *-e forced4drau6-* fans for *-e 5ain oilers T-e 5ain

oiler feed +u5+s and o*-er feed s9s*e5 eCui+5en* are also loca*ed around *-is fla* T-e *3o 5ain oilers occu+9 *-e

af*er end of *-is fla* and are arran6ed for roof firin6 T3o dis*illa*ion +lan*s are loca*ed for3ard arid *-e do5es*ic

3a*er su++l9 uni*s are loca*ed af*

T-e con*rolroo5 is loca*ed for3ard of *-e .25 fla* and con*ains

6rou+ s*ar*er oards are loca*ed for3ard of *-e console, 3-ic- faces in*o *-e 5ac-iner9 s+ace On *-e

.=2 5 fla* is *-e co5us*ion con*rol eCui+5en* for eac- oiler 3i*- a local dis+la9 +anel, al*-ou6- con*rol is fro5*-e 5ain con*rol roo5 T-e oiler fuel -ea*in6 and +u5+in6 5odule is also loca*ed -ere T-e de4aera*or is loca*ed

-i6- u+ in *-e casin6and silencers for *-e diesel al*erna*ors are in *-e funnel casin6Operation and maintenance

T-e res+onsiili*ies of *-e 5arine en6ineer are rarel9 confined *o *-e 5ac-iner9 s+ace Differen* co5+anies -a7e

differen* +rac*ices, u* usuall9 all s-i+oardmachinery, with the exception of radio equipment.


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. $ain oiler

2 FD fan

$ain feed +u5+@ Turo4aBerna*or

> #'4cooled e7a+ora*or

.0 Ho* 3a*er calorifier

.. F' +ressure *anB

.2 $ain *urines

. $ain 6earox

.@ T-rus*block

.1 $ain #' circ +u5+

.= $ain condenser

.> $ain ex*rac*ion +u5+

.8 !il6e?allas*pump

./ Drainstank etraction

+u5+s2. Turoalternator pum!

22 LO cooler

2@ LO 9+ass filler an

+u5+s 2= LO

+u5+s 28 Fire +u5+

2/ Auxiliar9 oiler0 Auxiliar9 oilerfeed healer

. HFO *ransfer +u5+ 5odule


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carried on 7er9 lar6e s-i+s, u* if no*, *-e elec*rical eCui+5en* is also 5ain*ained 9 *-e en6ineerA road4ased *-eore*ical and +rac*ical *rainin6 is *-erefore necessar9 for a 5arine en6ineer He 5us* e a

5ec-anical, elec*rical, air condi*ionin6, 7en*ila*ion and refri6era*ion en6ineer, as *-e need arises %nliBe -is s-ore4

ased o++osi*e nu5er in *-ese occu+a*ions, -e 5us* also deal 3i*- *-e s+ecialiGed reCuire5en*s of a floa*in6

+la*for5 in a 5os* corrosi7e en7iron5en* Fur*-er5ore -e 5us* e self sufficien* and ca+ale of 6e**in6 *-e o done

3i*- *-e facili*ies a* -is dis+osal T-e 5odern s-i+ is a co5+lex collec*ion of self4sus*ainin6 5ac-iner9 +ro7idin6 *-e

facili*ies *o su++or* a s5all co55uni*9 for a considerale +eriod of *i5e To si5+lif9 *-e unders*andin6 of all *-iseCui+5en* is *-e +ur+ose of *-is ooB T-is eCui+5en* is deal* 3i*- ei*-er as a co5+le*e s9s*e5 co5+risin6 s5all

i*e5s or indi7idual lar6er i*e5s In *-e la**er case, es+eciall9, *-e c-oices are of*en considerale A Bno3led6e of

5ac-iner9 and eCui+5en* o+era*ion +ro7ides *-e asis for effec*i7e 5ain*enance, and *-e *3o are considered in *urn

in *-e follo3in6 c-a+*ers

Chapter 2

Diesel enginesT-e diesel en6ine is a *9+e of in*ernal co5us*ion en6ine 3-ic- i6ni*es *-e fuel 9 inec*in6 i* in*o -o*, -i6-4+ressure

air in a co5us*ion c-a5er In co55on 3i*- all in*ernal co5us*ion en6ines *-e diesel en6ine o+era*es 3i*- a fixed

seCuence of e7en*s, 3-ic- 5a9 e ac-ie7ed ei*-er in four s*roBes or *3o, a s*roBe ein6 *-e *ra7el of *-e +is*on

e*3een i*s ex*re5e +oin*s Eac- s*roBe is acco5+lis-ed in -alf a re7olu*ion of *-e cranBs-af*

"our # stroke cycle

T-e four4s*roBe c9cle is co5+le*ed in four s*roBes of *-e +is*on, or *3o re7olu*ions of *-e cranBs-af* In order *o

o+era*e *-is c9cle *-e en6ine reCuires a 5ec-anis5 *o o+en and close *-e inle* and ex-aus* 7al7es

&onsider *-e +is*on a* *-e *o+ of i*s s*roBe, a +osi*ion Bno3n as *o+ dead cen*re :TD&; T-e inle* 7al7e o+ens and

fres- air is dra3n in as *-e +is*on 5o7es do3n :Fi6ure 2. :a;; A* *-e o**o5 of *-e s*roBe, ie o**o5 dead cen*re

:!D&;, *-e inle*, 7al7e closes and *-e air in *-e c9linder is co5+ressed :and conseCuen*l9 raised in *e5+era*ure; as

*-e +is*on rises :Fi6ure 2.:;; Fuel is inec*ed as *-e +is*on reac-es *o+ dead cen*re and co5us*ion *aBes +lace,

+roducin6 7er9 -i6- +ressure in *-e 6ases :Fi6ure 2.:c;; T-e +is*on is no3 forced do3n 9 *-ese 6ases and a*

o**o5 dead cen*re *-e ex-aus* 7al7e o+ens T-e final s*roBe is *-e ex-aus*in6 of *-e urn* 6ases as *-e +is*on rises *o

*o+ dead cen*re *o co5+le*e *-e c9cle :Fi6ure 2.:d;; T-e four dis*inc* s*roBes are Bno3n as


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$wo-stroke cycle

The two-stroke cycle is completed in two strokes of the piston or one revolution of the crankshaft. +n

order to operate this cycle where each event is accomplished in a very short time, the engine requires

a number of special arrangements. irst, the fresh air must be forced in under


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6ases and *-en *o fill or c-ar6e *-e s+ace 3i*- fres- air Ins*ead of 7al7es -oles, Bno3n as


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are forced apart-one up, one down-by the expanding gases igure /a00 The upper piston

opens the exhaust ports as it reaches the end of its-travel igure 1./b00. The lower piston,

a moment or two later opens the scavenge ports to charge the cylinder with fresh air and

remove the final traces of exhaust gas igure 1./20. 3nce the piston reach their extreme

points they both begin to move inward. This closes off the scavenge and exhaust ports for

the compression stroke to take place prior to fuel in4ection and combustion igure 1./d00.

This cycle is used in the )oxford engine, which is no longer manufactured although many

are still in operation.


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The four-stroke engine

A cross-section of a four-stroke cycle engine is made up of a piston which moves up and down in a

cylinder which is covered at the top by a cylinder head. The fuel in4ector, through which fuel enters

the cylinder, is located in the cylinder head. The inlet and exhaust valves are also housed in the

cylinder head and held shut by springs. The piston is 4oined to connecting rod by a gudgeon pin.

The bottom end or big end of the connecting rod is 4oined to the crankpin which forms part of thecrankshaft. 5ith this assembly

linear u+4and4do3n 5o7e5en* of *-e +is*on is con7er*ed in*o ro*ar9 5o7e5en* of *-e cranBs-af* T-e

cranBs-af* is arran6ed *o dri7e *-rou6- 6ears *-e ca5s-af*, 3-ic- ei*-er direc*l9 or *-rou6- +us-rods

o+era*es rocBer ar5s 3-ic- o+en *-e inle* and ex-aus* 7al7es T-e ca5s-af* is T-e +is*on is solidl9 connec*ed *o a

+is*on rod 3-ic- is a**ac-ed *o a cross-ead earin6 a* *-e o*-er end T-e *o+ end of *-e connec*in6 rod is also

oined *o *-e cross-ead earin6 Por*s are arran6ed in *-e c9linder liner for air inle* and a 7al7e in *-e

c9linder -ead enales *-e release of ex-aus* 6ases T-e inco5in6 air is +ressurised 9 a *uro4lo3er 3-ic-

is dri7en 9 *-e ou*6oin6 ex-aus* 6ases T-e cranBs-af* is su++or*ed 3i*-in *-e en6ine ed+la*e 9 *-e 5ain

earin6s A4fra5es are 5oun*ed on *-e ed+la*e and -ouse 6uides in 3-ic- *-e cross-ead *ra7els u+ and

do3n T-e en*ala*ure is 5oun*ed ao7e *-e fra5es and is 5ade u+ of *-e c9linders, c9linder -eads and *-e


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sca7en6e *runBin6

Comparison of two-stroke and four-stroke cycles

T-e 5ain difference e*3een *-e *3o c9cles is *-e +o3er de7elo+ed T-e *3o4s*roBe c9cle en6ine, 3i*- one

3orBin6 or +o3er s*roBe e7er9 re7olu*ion, 3ill, *-eore*icall9, de7elo+ *3ice *-e +o3er of a four4s*roBe en6ine

of *-e sa5e s3e+* 7olu5e Inefficien* sca7en6in6 -o3e7er and o*-er losses, reduce *-e +o3er ad7an*a6e *o

aou* .8 For a +ar*icular en6ine +o3er *-e *3o4s*roBe en6ine 3ill e consideral9 li6-*eran i5+or*an*

considera*ion for s-i+s or does *-e *3o4s*roBe en6ine reCuire *-e co5+lica*ed 7al7e o+era*in6 5ec-anis5

of *-e four4s*roBe T-e four4s*roBe en6ine -o3e7er can o+era*e efficien*l9 a* -i6- s+eeds

3-ic- offse*s i*s +o3er disad7an*a6eM i* also consu5es less lurica*in6 oil

Eac- *9+e of en6ine -as i*s a++lica*ions 3-ic- on oard s-i+ -a7e resul*ed in *-e slo3 s+eed :ie 804lOOre7?5in; 5ain +ro+ulsion diesel o+era*in6 on *-e *3o4s*roBe c9cle A* *-is lo3 s+eed *-e en6ine reCuires

no reduc*ion 6earox e*3een i* and *-e +ro+eller T-e four4s*roBe en6ine :usuall9 ro*a*in6 a* 5ediu5 s+eed,

e*3een 210 and >10 re7? 55; is used for auxiliaries suc- as al*erna*ors and so5e*i5es for 5ain +ro+ulsion

3i*- a 6earox *o +ro7ide a +ro+eller s+eed of e*3een 80 and l00 re7?5in

Power measurement

T-ere are *3o +ossile 5easure5en*s of en6ine +o3er *-e indicated. power and *-e shaft power. T-e

indica*ed +o3er is *-e +o3er de7elo+ed 3i*-in *-e en6ine c9linder and can e 5easured 9 an en6ine

indica*or T-e s-af* +o3er is *-e +o3er a7ailale a* *-e ou*+u* s-af* of *-e en6ine and can e 5easured usin6

a *orsion5e*er or 3i*- a raBe

The engine indicator

An engine indicator is shown in igure 1.6. +t is made up of a small piston of known si7e which operates in a

cylinder against a specially


13/65

calira*ed s+rin6 A 5a6nif9in6 linBa6e *ransfers *-e +is*on 5o7e5en* *o a dru5 on 3-ic- is 5oun*ed a

+iece of +a+er or card T-e dru5 oscilla*es :5o7es acB3ards and for3ards; under *-e +ull of *-e cord T-e

cord is 5o7ed 9 a reci+roca*in6 :u+ and do3n; 5ec-anis5 3-ic- is +ro+or*ional *o *-e en6ine +is*on

5o7e5en* in *-e c9linder T-e s*9lus dra3s ou* an indica*or dia6ra5 3-ic- re+resen*s *-e 6as +ressure on

*-e en6ine +is*on a* differen* +oin*s of *-e s*roBe, and *-e area of *-e indica*or dia6ra5 +roduced re+resen*s

*-e +o3er de7elo+ed in *-e +ar*icular c9linder T-e c9linder +o3er can e 5easured if *-e scalin6 fac*ors,

s+rin6 calira*ion and so5e asic en6ine de*ails are Bno3n T-e +rocedure is descried in *-e A++endix

T-e c9linder +o3er 7alues are co5+ared, and for alanced loadin6 s-ould all e *-e sa5e Adus*5en*s

5a9 *-en e 5ade *o *-e fuel su++l9 in order *o alance *-e c9linder loads

$orsionmeter

If *-e *orCue *rans5i**ed 9 a s-af* is Bno3n, *o6e*-er 3i*- *-e an6ular 7eloci*9, *-en *-e +o3er can e5easured, ie

s-af* +o3er N *orCue x an6ular 7eloci*9

T-e *orCue on a s-af* can e found 9 5easurin6 *-e s-ear s*ress or an6le of *3is* 3i*- a *orsion5e*er

A nu5er of differen* *9+es of *orsion5e*er are descried in &-a+*er .1

$he gas echange process

A asic +ar* of *-e c9cle of an in*ernal co5us*ion en6ine is *-e su++l9 of fres- air and re5o7al of ex-aus*6ases T-is is *-e 6as exc-an6e +rocess Scavengingis *-e re5o7al of ex-aus* 6ases 9 lo3in6 in fres- air%

Charging is *-e fillin6 of *-e en6ine c9linder 3i*- a su++l9 or c-ar6e of fres- air read9 for co5+ression'i*-supercharging a lar6e 5ass of air is su++lied *o *-e c9linder 9 lo3in6 i* in under +ressure Older

en6ines 3ere na*urall9 as+ira*ed Q *aBin6 fres- air onl9 a* a*5os+-eric +ressure $odern en6ines 5aBe useof ex-aus* 6as dri7en *uro4c-ar6ers *o su++l9 +ressurised fres- air for sca7en6in6 and su+erc-ar6in6 !o*-four4s*roBe and *3o4s*roBe c9cle en6ines 5a9 e +ressure c-ar6ed On *3o4s*roBe diesels an elec*ricall9dri7en auxiliar9 lo3er is usuall9 +ro7ided ecause *-e ex-aus* 6as dri7en *urolo3er canno* +ro7ide

enou6- air a* lo3 en6ine s+eeds, and *-e +ressurised air is usuall9 cooled *o increase *-e c-ar6e air densi*9An ex-aus* 6as dri7en *uroc-ar6in6 arran6e5en* for a slo34s+eed *3o4s*roBe c9cle diesel is s-o3n in

Fi6ure2/:a;A *urolo3er or *uroc-ar6er is an air co5+ressor dri7en 9 ex-aus* 6as :Fi6ure 2/:;; T-e sin6le s-af*

-as an ex-aus* 6as *urine on one end *-e air co5+ressor on *-e o*-er #ui*ale casin6 desi6n and s-af* sealsensure *-a* *-e *3o 6ases do no* 5ix Air is dra3n fro5 *-e 5ac-iner9 s+ace *-rou6- a fil*er and *-en

co5+ressed efore +assin6 *o *-e sca7en6e s+ace T-e ex-aus* 6as 5a9 en*er *-e *urine direc*l9 fro5 *-een6ine or fro5 a cons*an*4+ressure c-a5er Eac- of *-e s-af* earin6s -as i*s o3n inde+enden* lurica*ion

s9s*e5, and *-e 6as end of *-e casin6 is usuall9 3a*er4cooled

ScavengingEfficien* sca7en6in6 is essen*ial *o ensure a sufficien* su++l9 of fres- air for co5us*ion In *-e four4

s*roBe c9cle en6ine *-ere is an adeCua*e o7erla+ e*3een *-e air inle* 7al7e o+enin6 and *-e ex-aus* 7al7eclosin6 'i*- *3o4s*roBe c9cle en6ines *-is o7erla+ is li5i*ed and so5e sli6-* 5ixin6 of ex-aus* 6ases andinco5in6 air does occur Anu5er of differen* sca7en6in6 5e*-ods are in use in slo34s+eed *3o4s*roBeen6ines In eac- *-e fres- air en*ers as *-e inle* +or* is o+ened 9the downward movement of the pistonand con*inues un*il *-e +or* is dosed 9 *-e u+3ard 5o7in6 +is*on T-e flo3 +a*- of *-e sca7en6e air is


14/65

decided 9 *-e en6ine +or* s-a+e and desi6n and *-e ex-aus* arran6e5en*s T-ree asic s9s*e5s are in use*-e cross flo3, *-e loo+ and *-e uniflo3 All 5odern slo34s+eed diesel en6ines now use the uniflowscavenging system with a cylinder-head exhaust valve.


15/65

In cross sca7en6in6 *-e inco5in6 air is direc*ed u+3ards, +us-in6 *-e ex-aus* 6ases efore i* T-e

ex-aus* 6ases *-en *ra7el do3n and ou* of *-e ex-aus* +or*s Fi6ure 2.0:a; illus*ra*es *-e +rocess

In loo+ sca7en6in6 *-e inco5in6 air +asses o7er *-e +is*on cro3n *-en rises *o3ards *-e c9linder -ead

T-e ex-aus* 6ases are forced efore *-e air +assin6 do3n and ou* of ex-aus* +or*s loca*ed us* ao7e *-e

inle* +or*s T-e +rocess is s-o3n in Fi6ure 2.0:;

'i*- uniflo3 sca7en6in6 *-e inco5in6 air en*ers a* *-e lo3er end of *-e c9linder and lea7es a* *-e *o+T-e ou*le* a* *-e *o+ of *-e c9linder5a9 e +or*s or a lar6e 7al7e T-e +rocess is s-o3n in Fi6ure 2.0:c;

Eac- of *-e s9s*e5s -as 7arious ad7an*a6es and disad7an*a6es &ross sca7en6in6 reCuires *-e fi**in6

of a +is*on sBir* *o +re7en* air or ex-aus* 6as esca+e 3-en *-e +is*on is a* *-e *o+ of *-e s*roBe. 8oop

scavenge

arran6e5en*s -a7e lo3 *e5+era*ure air and -i6- *e5+era*ure ex-aus* 6as +assin6 *-rou6- adacen* +or*s,

causin6 *e5+era*ure differen*ial +role5s for *-e liner 5a*erial %niflo3 is *-e 5os* efficien* sca7en6in6

s9s*e5 u* reCuires ei*-er an o++osed +is*on arran6e5en* or an ex-aus* 7al7e in *-e c9linder -ead All *-ree

s9s*e5s -a7e *-e +or*s an6led *o s3irl *-e inco5in6 air and direc* i* in *-e a++ro+ria*e +a*-

Scavenge fires

&9linderoil can collec*in *-e sca7en6e s+ace of an en6ine %nurned fuel and caron 5a9 also e lo3n in*o

*-e sca7en6e s+ace as a resul* of defec*i7e +is*on rin6s, faul*9 *i5in6, a defec*i7e inec*or, e*c A uild4u+ of

*-is fla55ale 5ix*ure +resen*s a dan6er as a lo3 +as* of -o* 6ases fro5 *-e c9linder 5a9 i6ni*e *-e

5ix*ure, and cause a sca7en6e fire

A loss of en6ine +o3er 3ill resul*, 3i*- -i6- ex-aus* *e5+era*ures a* *-e affec*ed c9linders T-e affec*ed

*uro4c-ar6ers 5a9 sur6e and s+arBs 3ill e seen a* *-e sca7en6e drains Once a fire is de*ec*ed *-e en6ine


16/65

s-ould e slo3ed do3n, fuel s-u* off fro5 *-e affec*ed c9linders and c9linder lurica*ion increased All *-e

sca7en6e drains s-ould e closed A s5all fire 3ill CuicBl9 urn ou*, u* 3-ere *-e fire +ersis*s *-e en6ine

5us* e s*o++ed A fire ex*in6uis-in6 5ediu5 s-ould *-en e inec*ed *-rou6- *-e fi**in6s +ro7ided in *-e

sca7en6e *runBin6 On no accoun* s-ould *-e *runBin6be opened up.

To a7oid sca7en6e fires occurrin6 *-e en6ine *i5in6 and eCui+5en* 5ain*enance s-ould e correc*l9

carried ou* T-e sca7en6e *runBin6 s-ould e re6ularl9 ins+ec*ed and cleaned if necessar9 '-ere caron or

oil uild u+ is found in *-e sca7en6e, i*s source s-ould e de*ec*ed and *-e faul* re5edied #ca7en6e drainss-ould e re6ularl9 lo3n and an9 oil disc-ar6es in7es*i6a*ed a* *-e, firs* o++or*uni*9

Fuel oil system The fuel oil system for a diesel engine can be considered in two parts9thefuel !u""lyand the fuel in#ectionsystems. uel supply deals with the provision of fuel oil suitable foruse by the in4ection system.Fuel oil supply for a two-stroke diesel

A slow-speed two-stroke diesel is usually arranged to operate continuously on heavy fuel and have

available a diesel oil supply for manoeuvring conditions.

+n the system shown in igure 1.**, the oil is stored in tanks in the double bottom from which it is

pumped to a settling tank and heated.

Af*er +assin6 *-rou6- cen*rifu6es *-e cleaned, -ea*ed oil is +u5+ed *o a dail9 ser7ice *anB Fro5 *-e dail9

ser7ice *anB *-e oil flo3s *-rou6- a *-ree43a9 7al7e *o a 5ixin6 *anB A flo3 5e*er is fi**ed in*o *-e s9s*e5

*o indica*e fuel consu5+*ion !oos*er +u5+s are used *o +u5+ *-e oil *-rou6- -ea*ers and a 7iscosi*9

re6ula*or *o *-e en6ine4dri7en fuel +u5+s T-e fuel +u5+s 3ill disc-ar6e -i6-4+ressure fuel *o *-eir


17/65

res+ec*i7e inec*ors

T-e 7iscosi*9 re6ula*or con*rols *-e fuel oil *e5+era*ure in order *o +ro7ide *-e correc* 7iscosi*9 for

co5us*ion A +ressure re6ula*in6 7al7e ensures a cons*an*4+ressure su++l9 *o *-e en6ine4dri7en +u5+s,

and a +re43ar5in6 9+ass is used *o -ea* u+ *-e fuel efore s*ar*in6 *-e en6ine A diesel oil dail9 ser7ice

*anB 5a9 e ins*alled and is connec*ed *o *-e s9s*e5 7ia a *-ree43a9 7al7e T-e en6ine can e s*ar*ed u+

and 5anoeu7red on diesel oil or e7en a lend 0. diesel and -ea79 fuel oil T-e 5ixin6 *anB is used *o

collec* recircula*ed oil and also ac*s as a uffer or reser7e *anB as i* 3ill su++l9 fuel 3-en *-e dail9 ser7ice*anB is e5+*9

T-e s9s*e5 includes 7arious safe*9 de7ices suc- as lo34le7el alar5s and re5o*el9 o+era*ed *anB ou*le*

7al7es 3-ic- can e closed in *-e e7en* of a Fire

"uel in&ection

T-e func*ion of *-e fuel inec*ion s9s*e5 is *o +ro7ide *-e ri6-* a5oun* of fuel a* *-e ri6-* 5o5en* and in a

sui*ale condi*ion for *-e co5us*ion +rocess T-ere 5us* *-erefore e so5e for5 of 5easured fuel su++l9, a

5eans of *i5in6 *-e deli7er9 and *-e a*o5iGa*ion of *-e fuel T-e inec*ion of *-e fuel is ac-ie7ed 9 *-e

loca*ion of ca5s on a ca5s-af* T-is ca5s-af* ro*a*es a* en6ine s+eed for a *3o4s*roBe en6ine and a* -alf

en6ine s+eed for a four4s*roBe T-ere are *3o asic s9s*e5s in use, eac- of 3-ic- e5+lo9s a co5ina*ion of

5ec-anical and -9draulic o+era*ions T-e 5os* co55on s9s*e5 is *-e erB +u5+ *-e o*-er is *-e co55on

rail

'erk pump system

In *-e erB +u5+ s9s*e5 of fuel inec*ion a se+ara*e inec*or +u5+ exis*s for eac- c9linder T-e inec*or +u5+

is usuall9 o+era*ed once e7er9 c9cle 9 a ca5 on *-e ca5s-af* T-e arrel and +lun6er of *-e inec*or +u5+

are di5ensioned *o sui* *-e en6ine fuel reCuire5en*s Por*s in *-e arrel and slo*s in *-e +lun6er or adus*ale

s+ill 7al7es ser7e *o re6ula*e *-e fuel deli7er9 :a 5ore de*ailed ex+lana*ion follo3s; Eac- inec*or +u5+

su++lies *-e inec*or or inec*ors for one c9linder T-e needle 7al7e in *-e inec*or 3ill lif* a* a +re4se*

+ressure 3-ic- ensures *-a* *-e fuel 3ill a*o5iGe once i* en*ers *-e c9linder

T-ere are *3o +ar*icular *9+es of fuel +u5+ in use, *-e 7al7e4con*rolled disc-ar6e *9+e and *-e -elix or

-elical ed6e +u5+ al7e4con*rolled +u5+s are used on slo34s+eed *3o4s*roBe en6ines and *-e -elix *9+e for

all 5ediu54 and -i6-4s+eed four4s*roBe en6ines

Heli-type in!ector pump

The in4ector pump is operated by a cam which drives the plunger up and down. The timing of the

in4ection can be altered by raising or lowering the pump plunger in relation to the cam. The pump

has a constant stroke and the amount of fuel delivered is regulated by rotating the pump plunger

which has a specially arranged helical groove cut into it.

The fuel is supplied to the pump through ports or openings at % igure 1.*10. As the plunger

moves down, fuel enters the cylinder. As the plunger moves up, the ports at : are closed and the

fuel is pressurised and delivered to the in4ector no77le at very high pressure. 5hen the edge of the

helix at " uncovers the spill port ) pressure is lost and fuel delivery to the in4ector stops. A non-

return valve on the delivery side of the pump closes to stop fuel oil returning from the in4ector. uel

will again be drawn in on the plunger downstroke and the process will be repeated.

The plunger may be rotated in the cylinder by a rack and pinion arrangement on a sleeve whichis keyed to the plunger. This will move the edge " up or down to reduce or increase the amount of

fuel pumped into the cylinder. The rack is connected to the throttle control or governor of the

engine.

This type of pump, with minor variations, is used on many four-stroke diesel engines.

(al)e-controlled pump

+n the variable in4ection timing ;+T0 pump used in (A< :=5 engines the governor output shaft is

the controlling parameter. Two linkages are actuated by the regulating shaft of the governor.

The upper control linkage changes the in4ection timing by raising or lowering the plunger in

relation to the cam. The lower linkage rotates the pump plunger and thus the helix in order to vary

the pump output igure 1.*%0.

+n the 'ul7er variable in4ection timing system the governor output is connected to a suction valve

and a spill valve. The closing of the pump suction valve determines the beginning of in4ection.

3peration of the spill valve will control the end of in4ection by releasing fuel pressure.


18/65


19/65

Common rail systemThe common rail system has one high-pressure multiple plunger fuel pump igure 1.*$0.The

fuel is discharged into a manifold or rail which is maintained at high pressure. rom this common

rail fuel is supplied to all the in4ectors in the various cylinders. :etween the rail and the in4ector

or in4ectors for a particular cylinder is a timing valve which determines the timing and extent of

fuel delivery. 'pillvalves are connected to the manifold or rail to release excess pressure and

accumulator bottles which dampen out pump pressure pulses. The in4ectors in a common rail

system are often referred to as fuel valves.


20/65

Timing valve

T-e *i5in6 7al7e in *-e co55on rail s9s*e5 is o+era*ed 9 a ca5 and le7er :Fi6ure 2.1; '-en *-e *i5in6

7al7e is lif*ed 9 *-e ca5 and le7er *-e -i6-4+ressure fuel flo3s *o *-e inec*or T-e *i5in6 7al7e o+era*in6

le7er is fixed *o a slidin6 rod 3-ic- is +osi*ioned accordin6 *o *-e 5anoeu7rin6 le7er se**in6 *o +ro7ide *-e

correc* fuel Cuan*i*9 *o *-e c9linder


21/65

T-e fuel inec*or

A *9+ical fuel inec*or is s-o3n in Fi6ure 2.= I* can e seen *o e *3o asic +ans, *-e noGGle and *-e

noGGle -older or od9 T-e -i6-4+ressure fuel en*ers and *ra7els do3n a +assa6e in *-e od9 and *-en in*o

a +assa6e in *-e noGGle, endin6 finall9 in a c-a5er surroundin6 *-e needle 7al7e T-e needle 7al7e is -eld

closed on a 5i*ered sea* 9 an in*er5edia*e s+indle and a s+rin6 in *-e inec*or od9 T-e s+rin6


22/65

+ressure, and -ence *-e inec*or o+enin6 +ressure, can e se* 9 a co5+ression nu* 3-ic- ac*s on *-e s+rin6

T-e noGGle and inec*or od9 are 5anufac*ured as a 5a*c-in6 +air and are accura*el9 6round *o 6i7e a 6ood

oil seal T-e *3o are oined 9 a noGGle nu*

T-e needle 7al7e 3ill o+en 3-en *-e fuel +ressure ac*in6 on *-e needle 7al7e *a+ered face exer*s a

sufficien* force *o o7erco5e *-e s+rin6 co5+ression T-e fuel *-en flo3s in*o a lo3er c-a5er and is forced

ou* *-rou6- a series of *in9 -oles T-e s5all -oles are siGed and arran6ed *o a*o5iGe, or reaB in*o *in9dro+s, all of *-e fuel oil, 3-ic- 3ill *-en readil9 urn Once *-e inec*or +u5+ or *i5in6 7al7e cu*s off *-e

-i6- +ressure fuel su++l9 *-e needle 7al7e 3ill s-u* CuicBl9 under *-e s+rin6 co5+ression force

All slo34s+eed *3o4s*roBe en6ines and 5an9 5ediu54s+eed four4s*roBe en6ines are no3 o+era*ed al5os*

con*inuousl9 on -ea79 fuel A fuel circula*in6 s9s*e5 is *-erefore necessar9 and *-is is usuall9 arran6ed

3i*-in *-e fuel inec*or Durin6 inec*ion *-e -i6-4+ressure fuel 3ill o+en *-e circula*ion 7al7e for inec*ion

*o *aBe +lace '-en *-e en6ine is s*o++ed *-e fuel oos*er +u5+ su++lies fuel 3-ic- *-e circula*ion 7al7e

direc*s around *-e inec*or od9

Older en6ine desi6ns 5a9 -a7e fuel inec*ors 3-ic- are circula*ed 3i*- coolin6 3a*er

Lubrication

T-e lurica*ion s9s*e5 of an en6ine +ro7ides a su++l9 of lurica*in6 oil *o *-e 7arious 5o7in6 +ar*s in *-e

en6ine I*s 5ain func*ion is *o enale *-e for5a*ion of a fil5 of oil e*3een *-e 5o7in6 +ar*s, 3-ic- reducesfric*ion and 3ear T-e lurica*in6 oil is also used as a cleaner and in so5e en6ines as a coolan*

Lubricating oil system

Lurica*in6 oil for an en6ine is s*ored in *-e o**o5 of *-e cranBcase, Bno3n as *-e su5+, or in a drain *anB

loca*ed enea*- *-e en6ine :Fi6ure 2.>; T-e oil is dra3n fro5 *-is *anB *-rou6- a s*rainer, one of a +air of

+u5+s, in*o one of a +air of fine fil*ers I* is *-en +assed *-rou6- a cooler efore en*erin6 *-e en6ine and

ein6 dis*riu*ed *o *-e 7arious ranc- +i+es T-e ranc- +i+e for a +ar*icular c9linder 5a9 feed *-e 5ain

earin6, for ins*ance #o5e of *-is oil 3ill +ass alon6 a drilled +assa6e in *-e cranBs-af* *o *-e o**o5 end

earin6 and *-en u+ a drilled +assa6e in *-e connec*in6 rod *o *-e 6ud6eon +in or cross-ead earin6 An

alar5 a* *-e end of *-e dis*riu*ion +i+e ensures *-a* adeCua*e +ressure is 5ain*ained 9 *-e +u5+ Pu5+s

and fine fil*ers are arranged in duplicate with one as standby.

T-e fine fil*ers 3ill e arran6ed so *-a* one can e cleaned 3-ile *-e o*-er is o+era*in6 Af*er use in *-e

en6ine *-e lurica*in6 oil drains acB *o *-e su5+ or drain *anB for re4use A le7el 6au6e 6i7es a local read4

ou* of *-e drain *anB con*en*s A cen*rifu6e is arran6ed for cleanin6 *-e lurica*in6 oil in *-e s9s*e5 and clean


23/65

oil can e +ro7ided fro5 a s*ora6e *anB

T-e oil cooler is circula*ed 9 sea 3a*er, 3-ic- is a* a lo3er +ressure *-an *-e oil As a resul* an9 leaB in

*-e cooler 3ill 5ean a loss of oil and no* con*a5ina*ion of *-e oil 9 sea 3a*er

'-ere *-e en6ine -as oil4cooled +is*ons *-e9 3ill e su++lied fro5 *-e lurica*in6 oil s9s*e5, +ossil9 a* a

-i6-er +ressure +roduced 9 oos*er +u5+s, e6 #ulGer RTA en6ine An a++ro+ria*e *9+e of lurica*in6 oil

5us* e used for oil4lurica*ed +is*ons in order *o a7oid caron de+osi*s on *-e -o**er +ar*s of *-e s9s*e5

Cylinder lubrication

Lar6e slo34s+eed diesel en6ines are +ro7ided 3i*- a se+ara*e lurica*ion s9s*e5 for *-e c9linder liners Oil is

inec*ed e*3een *-e liner and *-e +is*on 9 5ec-anical lurica*ors 3-ic- su++l9 *-eir indi7idual c9linder A

s+ecial *9+e of oil is used 3-ic- is no* reco7ered As 3ell as lurica*in6, i* assis*s in for5in6 a 6as seal and

con*ains addi*i7es 3-ic- clean *-e c9linder liner

"ooling

&oolin6 of en6ines is ac-ie7ed 9 circula*in6 a coolin6 liCuid around in*ernal +assa6es 3i*-in *-e en6ine T-e

coolin6 liCuid is *-us -ea*ed u+ and is in *urn cooled 9 a sea 3a*er circula*ed cooler 'i*-ou* adeCua*e

coolin6 cer*ain +ar*s of *-e en6ine 3-ic- are ex+osed *o 7er9 -i6- *e5+era*ures, as a resul* of urnin6 fuel,3ould soon fail &oolin6 enales *-e en6ine 5e*als *o re*ain *-eir 5ec-anical +ro+er*ies T-e usual coolan*

used is fres- 3a*er sea 3a*er is no* used direc*l9 as a coolan* ecause of i*s corrosi7e ac*ion Lurica*in6 oil

is so5e*i5es used for +is*on coolin6 since leaBs in*o *-e cranBcase 3ould no* cause +role5s As a resul* of

i*s lo3er s+ecific -ea* -o3e7er aou* *3ice *-e Cuan*i*9 of oil co5+ared *o 3a*er 3ould e reCuired

"resh water cooling system

A 3a*er coolin6 s9s*e5 for a slo34s+eed diesel en6ine is s-o3n in Fi6ure 2.8 I* is di7ided in*o *3o se+ara*e

s9s*e5s one for coolin6 *-e c9linder acBe*s, c9linder -eads and *uro4lo3ersM *-e o*-er for +is*on coolin6

T-e c9linder acBe* coolin6 3a*er af*er lea7in6 *-e en6ine +asses *o a sea43a*er4circula*ed cooler and

*-en in*o *-e acBe*43a*er circula*in6 +u5+s I* is *-en +u5+ed around *-e c9linder acBe*s, c9linder -eads

and *uro4lo3ers A -eader *anB allo3s for ex+ansion and 3a*er 5aBe4u+ in *-e s9s*e5 en*s are led

fro5 *-e en6ine *o *-e -eader *anB for *-e release of air fro5 *-e coolin6 3a*er A -ea*er in *-e circui*

facili*a*es 3ar5in6 of *-e en6ine +rior *o s*ar*in6 9 circula*in6 -o* 3a*er

T-e +is*on coolin6 s9s*e5 e5+lo9s si5ilar co5+onen*s, exce+* *-a* a drain *anB is used ins*ead of a

-eader *anB and *-e 7en*s are *-en led *o -i6- +oin*s in *-e 5ac-iner9 s+ace A se+ara*e +is*on coolin6

s9s*e5 is used *o li5i* an9 con*a5ina*ion fro5 +is*on coolin6 6lands *o *-e +is*on coolin6 s9s*e5 onl9


24/65

Sea water cooling system

T-e 7arious coolin6 liCuids 3-ic- circula*e *-e en6ine are *-e5sel7es cooled 9 sea 3a*er T-e usual

arran6e5en* uses indi7idual coolers for lurica*in6 oil, acBe* 3a*er, and *-e +is*on coolin6 s9s*e5, eac-

cooler ein6 circula*ed 9 sea 3a*er #o5e 5ode5 s-i+s use 3-a* is Bno3n as a


25/65

Starting air system

Diesel en6ines are s*ar*ed 9 su++l9in6 co5+ressed air in*o *-e c9linders in *-e a++ro+ria*e seCuence for *-e

reCuired direc*ion A su++l9 co5+ressed air is s*ored in air reser7oirs or


26/65

Control andsafety de)ices

Governors

T-e +rinci+al con*rol de7ice on an9 en6ine is *-e 6o7ernor I* 6o7erns or con*rols *-e en6ine s+eed a* so5e

fixed 7alue 3-ile +o3er ou*+u* c-an6es *o 5ee* de5and T-is is ac-ie7ed 9 *-e 6o7ernor au*o5a*icall9adus*in6 *-e en6ine fuel +u5+ se**in6s *o 5ee* *-e desired load a* *-e se* s+eed (o7ernors for diesel

en6ines are usuall9 5ade u+ of *3o s9s*e5s a s+eed sensin6 arran6e5en* and a -9draulic uni* 3-ic-

o+era*es on *-e fuel +u5+s *o c-an6e *-e en6ine +o3er ou*+u*

,echanical go)ernor

A fl93ei6-* asse5l9 is used *o de*ec*en6ine s+eed T3o fl93ei6-*s are fi**ed *o a +la*e or all-ead 3-ic-

ro*a*esaou* a 7er*icalaxis dri7en 9 a 6ear 3-eel :Fi6ure 222; T-e ac*ion of cen*rifu6al force *-ro3s *-e

3ei6-*s ou*3ardsM *-is lif*s *-e 7er*ical s+indle and co5+resses *-e s+rin6 un*il an eCuiliriu5 si*ua*ion

is reac-ed T-e eCuiliriu5 +osi*ion or se* s+eed 5a9 e c-an6ed 9 *-e s+eed selec*or 3-ical*ers *-e

s+rin6 co5+ression

As *-e en6ine s+eed increases *-e 3ei6-*s 5o7e ou*3ards and raise *-e s+indleM a s+eed decrease 3ill

lo3er *-e s+indleT-e -9draulic uni* is connec*ed *o *-is 7er*ical s+indle and ac*s as a +o3er source *o 5o7e *-e en6ine

fuel con*rols A +is*on 7al7e connec*ed *o *-e 7er*ical s+indle su++lies or drains oil fro5 *-e +o3er

+is*on 3-ic- 5o7es *-e fuel con*rols de+endin6 u+on *-e fl93ei6-* 5o7e5en* If *-e en6ine s+eed

increases *-e 7er*ical s+indle rises, *-e +is*on 7al7e rises and oil is drained fro5 *-e +o3er +is*on 3-ic-


27/65

resul*s in a fuel con*rol 5o7e5en* T-is reduces fuel su++l9 *o *-e en6ine and slo3s i* do3n I* is, in

effec*, a +ro+or*ional con*roller :see &-a+*er .1;

The actual arrangement of mechanical engine governors will vary considerably but most will

operate as described above.

#lectric governor

The electric governor uses a combination of electrical and mechanical components in its

operation. The speed sensing device is a small magnetic pick-up coil. The rectified, or d . c.,

voltage signal is used in con4unction with a desired or set speed signal to operate a hydraulic unit.

This unit will then move the fuel controls in the appropriate direction to control the engine speed.

"ylinder relief valve

The cylinder relief valve is designed to relieve pressures in excess of *2> to 12> above normal.

A spring holds the valve closed and its lifting pressure is set by an appropriate thickness of packing

piece igure 1.1%0. 3nly a small amount of lift is permitted and the escaping gases are directed to

a safe outlet. The valve and spindle are separate to enable the valve to correctly seat itself after

opening.

The operation of this device indicates a fault in the engine which should be discovered and

corrected. The valve itself should then be examined at the earliest opportunity.

"rankcase oil mist detector

T-e +resence of an oil 5is* in *-e cranBcase is *-e resul* of oil 7a+oriGa*ion caused 9 a -o* s+o* Ex+losi7econdi*ions can resul* if a uild u+ of oil 5is* is allo3ed T-e oil 5is* de*ec*or uses +-o*oelec*ric cells *o

5easure s5all increases in oil 5is* densi*9 A 5o*or dri7en fan con*inuousl9 dra3s sa5+les of cranBcase oil5is* *-rou6- a 5easurin6 *ue An increased 5e*er readin6 and alar5 3ill resul* if an9 cranBcase sa5+le


28/65


29/65

doors are fi**ed T-ese 7al7es ser7e *o relie7e excessi7e cranBcase +ressures and s*o+ fla5es ein6 e5i**ed

fro5 *-e cranBcase T-e9 5us* also e self closin6 *o s*o+ *-e re*urn of a*5os+-eric air *o *-e cranBcase

arious desi6ns and arran6e5en*s of *-ese 7al7es exis* 3-ere, on lar6e slo34s+eed diesels, *3o door *9+e

7al7es 5a9 e fi**ed *o eac- cranBcase or, on a 5ediu54s+eed diesel, one 7al7e 5a9 e used One desi6n of

ex+losion relief 7al7e is s-o3n in Fi6ure 22@ A li6-* s+rin6 -olds *-e 7al7e closed a6ains* i*s sea* and a seal

rin6 co5+le*es *-e oin* A deflec*or is fi**ed on *-e ou*side of *-e en6ine *o safe6uard +ersonnel fro5 *-e ou*

flo3in6 6ases, and inside *-e en6ine, o7er *-e 7al7e o+enin6, an oil 3e**ed 6auGe ac*s as a fla5e *ra+ *o s*o+an9 fla5es lea7in6 *-e cranBcase Af*er o+era*ion *-e 7al7e 3ill close au*o5a*icall9 under *-e ac*ion of *-e

s+rin6. Turning gear

T-e *urnin6 6ear or *urnin6 en6ine is a re7ersile elec*ric 5o*or 3-ic- dri7es a 3or5 6ear 3-ic- can e

connec*ed 3i*- *-e *oo*-ed fl93-eel *o *urn a lar6e diesel A slo34s+eed dri7e is *-us +ro7ided *o enale

+osi*ionin6 of *-e en6ine +ar*s for o7er-aul +ur+oses T-e *urnin6 6ear is also used *o *urn *-e en6ine one or

*3o re7olu*ions +rior *o s*ar*in6 T-is is a safe*9 c-ecB *o ensure *-a* *-e en6ine is free *o *urn and *-a* no

3a*er -as collec*ed in *-e c9linders T-e indica*or cocBs 5us* al3a9s e o+en 3-en *-e *urnin6 6ear is

o+era*ed

Medium- and slow-speed diesels

(edium-speed diesels, e.g. 1/2 to ?/2rev@min, and slow-speed diesels, e.g. *22 to *12rev@min,

each have their various advantages and disadvantages for various duties on board ship.

T-e slo34s+eed *3o4s*roBe c9cle diesel is used for 5ain +ro+ulsi=n uni*s since i* can e direc*l9 cou+led

*o *-e +ro+eller and s-af*in6 I* +ro7ides -i6- +o3ers, can urn lo346rade fuels and -as a -i6- *-er5al

efficienc9 T-e c9linders and cranBcase are isola*ed, 3-ic- reduces con*a5ina*ion and +er5i*s *-e use of

s+ecialiGed lurica*in6 oils in eac- area T-e use of *-e *3o4s*roBe c9cle usuall9 5eans *-ere are no inle* and

ex-aus* 7al7es T-is reduces 5ain*enance and si5+lifies en6ine cons*ruc*ion

$ediu54s+eed four4s*roBe en6ines +ro7ide a e**er +o3er4*o43ei6-* ra*io and +o3er4*o4siGe ra*io and

*-ere is also a lo3er ini*ial cos* for eCui7alen* +o3er T-e -i6-er s+eed, -o3e7er, reCuires *-e use of a

6earox and flexile cou+lin6s for 5ain +ro+ulsion use &9linder siGes are s5aller, reCuirin6 5ore uni*s and

*-erefore 5ore 5ain*enance, u* *-e increased s+eed +ar*l9 offse*s *-is &9linder liners are of si5+le

cons*ruc*ion since *-ere are no +or*s, u* c9linder -eads are 5ore co5+lica*ed and 7al7e o+era*in6 6ear isreCuired #ca7en6in6 is a +osi*i7e o+era*ion 3i*-ou* use of sca7en6e *runBin6, *-us *-ere can e no sca7en6e

fires !e**er Cuali*9 fuel is necessar9 ecause of *-e -i6-er en6ine s+eed, and lurica*in6 oil consu5+*ion is

-i6-er *-an for a slo34s+eed diesel En6ine -ei6-* is reduced 3i*- *runB +is*on desi6n arid *-ere are fe3er

5o7in6 +ar*s +er c9linder T-ere are, -o3e7er, in *o*al 5ore +ar*s for 5ain*enance, al*-ou6- *-e9 are s5aller

and 5ore 5ana6eale

T-e ee en6ine confi6ura*ion is used 3i*- so5e 5ediu54s+eed en6ine desi6ns *o fur*-er reduce *-e siGe

and 3ei6-* for a +ar*icular +o3er

"ouplings$ clutches and gear%oes

'-ere *-e s-af* s+eed of a 5ediu54s+eed diesel is no* sui*ale for i*s a++lica*ion, e6 3-ere a lo3 s+eed

dri7e for a +ro+eller is reCuired, a 6earox 5us* e +ro7ided !e*3een *-e en6ine and 6earox i* is usual *o fi*so5e for5 of flexile cou+lin6 *o da5+en ou* 7ira*ions T-ere is also of*en a need for a clu*c- *o disconnec*

*-e en6ine fro5 *-e 6earox

Couplings

Elas*ic or flexile cou+lin6s allo3 sli6-* 5isali6n5en* and da5+ ou* or re5o7e *orCue 7aria*ions fro5 *-e

en6ine T-e cou+lin6 5a9 in addi*ion func*ion as a clu*c- or disconnec*in6 de7ice &ou+lin6s 5a9 e

5ec-anical, elec*rical, -9draulic or +neu5a*ic in o+era*ion I* is usual *o co5ine *-e func*ion of clu*c- 3i*-

a cou+lin6and *-is isno* readil9 +ossile 3i*- *-e 5ec-anical cou+lin6

"lutches

A clu*c- is a de7ice *o connec* or se+ara*e a dri7in6 uni* fro5 *-e uni* i* dri7es 'i*- *3o en6ines connec*ed*o a 6earox a clu*c-


30/65

dri7en i5+eller +ro7ides Bine*ic ener69 *o *-e oil 3-ic- *rans5i*s *-e dri7e *o *-e runner T-rus* earin6s

5us* e +ro7ided on ei*-er side of *-e cou+lin6 ecause of *-e

axial *-rus* de7elo+ed 9 *-is cou+lin6A +la*e4*9+e clu*c- consis*s of +ressure +la*es and clu*c- +la*es arran6ed in a clu*c- s+ider :Fi6ure 22=;

A for3ard and an af* clu*c- asse5l9 are +ro7ided, and an ex*ernall9 5oun*ed selec*or 7al7e asse5l9 is *-e

con*rol de7ice 3-ic- -9draulicall9 en6a6es *-e desired clu*c- T-e for3ard clu*c- asse5l9 is 5ade u+ of

*-e in+u* s-af* and *-e for3ard clu*c- s+ider T-e in+u* s-af* includes *-e for3ard dri7en 6ear and, a* i*sex*re5e end, a -u 3i*- *-e s*eel +ressure +la*esof the


31/65

for3ard clu*c- asse5l9 s+line4connec*ed, ie free *o slide T-us 3-en *-e in+u* s-af* *urns, *-e for3ard

dri7en 6ear and *-e for3ard clu*c- +ressure +la*es 3ill ro*a*e T-e for3ard clu*c- +la*es are +osi*ioned

e*3een *-e +ressure +la*es and are s+line4connec*ed *o *-e for3ard clu*c- s+ider or -ousin6 T-is for3ard

clu*c- s+ider for5s +ar* of *-e for3ard +inion asse5l9 3-ic- surrounds u* does no* *ouc- *-e in+u* s-af*

T-e cons*ruc*ion of *-e re7erse clu*c- s+ider is si5ilar

!o*- *-e for3ard and re7erse +inions are in cons*an* 5es- 3i*- *-e ou*+u* 6ear 3-eel 3-ic- ro*a*es *-eou*+u* s-af* In *-e neu*ral +osi*ion *-e en6ine is ro*a*in6 *-e in+u* s-af* and o*- dri7en 6ear 3-eels, u* no*

*-e ou*+u* s-af* '-en *-e clu*c- selec*or 7al7e is 5o7ed *o *-e a-ead +osi*ion, a +is*on asse5l9 5o7es *-e

clu*c- +la*es and +ressure +la*es in*o con*ac* A fric*ion 6ri+ is crea*ed e*3een *-e s5oo*- +ressure +la*e and

*-e clu*c- +la*e linin6s and *-e for3ard +inion ro*a*es T-e for3ard +inion dri7es *-e ou*+u* s-af* and for3ard

+ro+ulsion 3ill occur T-e +rocedure 3-en *-e selec*or 7al7e is 5o7ed *o *-e as*ern +osi*ion is si5ilar u*

no3 *-e re7erse +inion dri7es *-e 4ou*+u* s-af* in *-e o++osi*e direc*ion

earboes

T-e 6earin6 arran6e5en* used *o reduce *-e 5ediu54s+eed en6ine dri7e do3n *o sui*ale +ro+eller

re7olu*ions is al3a9s sin6le reduc*ion and usuall9 sin6le -elical Reduc*ion ra*ios ran6e fro5 aou* 2. *o @.

on 5odern ins*alla*ions

Pinion and 6ear3-eel arran6e5en*s 3ill e si5ilar *o *-ose for s*ea5 *urines as descried in &-a+*er ,exce+* *-a* *-e9 3il* e sin6le -elical or e+ic9clic

&eversing

'-ere a 6earox is used 3i*- a diesel en6ine, re7ersin6 6ears 5a9 e incor+ora*ed so *-a* *-e en6ine i*self

is no* re7ersed '-ere a con*rollale +i*c- +ro+eller is in use *-ere is no reCuire5en* *o re7erse *-e 5ain

en6ine Ho3e7er, 3-en i* is necessar9 *o run *-e en6ine in re7erse i* 5us* e s*ar*ed in re7erse and *-e fuel

inec*ion *i5in6 5us* e c-an6ed '-ere ex-aus* *i5in6 or +o++e* 7al7es are used *-e9 also 5us* e re*i5ed

'i*- erB4*9+e fuel +u5+s *-e fuel ca5s on *-e ca5s-af* 5us* e re+osi*ioned T-is can e done 9 -a7in6 a

se+ara*e re7ersin6 ca5 and 5o7in6 *-e ca5s-af* axiall9 *o rin6 i* in*o +osi*ion< Al*erna*i7el9 a los*45o*ion

clu*c- 5a9 e used in conunc*ion 3i*- *-e a-ead +u5+4*i5in6 ca5

T-e fuel +u5+ ca5 and los*45o*ion clu*c- arran6e5en* is s-o3n in Fi6ure 22> T-e s-a+in6 of *-e ca5

resul*s in a +eriod of +u5+in6 firs* *-en aou* .0 of fuel inec*ion efore *o+ dead cen*re and aou* 1 af*er

*o+ dead cen*re A +eriod of d3ell *-en occurs 3-en *-e fuel +u5+ +lun6er does no* 5o7e A full9 re7ersile

ca5 3ill e s955e*rical aou* *-is +oin*, as s-o3n T-e an6ular +eriod e*3een *-e *o+ dead cen*re +oin*s

for a-ead and as*ern runnin6 3ill e *-e


32/65

ele5en* T-e ournal +ins are *-en s-runB in*o *-e cranB 3es For all u* *-e lar6er nu5ers of en6ine

c9linders, *-e cranBs-af* is a sin6leuni* T-e5ain ournal and o**o54end earin6s are *-in43alled s-ells

lined 3i*- 3-i*e 5e*al T-e for6ed connec*in6 rod -as a


33/65

Fuel inec*ion uses *-e erB +u5+ s9s*e5 and a 'ood3ard4*9+e -9draulic 6o7ernor is used *o con*rolen6ine s+eed '-ere *-e en6ine -as oil4cooled +is*ons *-e9 3ill e su++lied fro5 *-e lurica*in6 oil s9s*e5,

+ossil9 a* a -i6-er +ressure +roduced 9 oos*er +u5+s, e6 *-e #ulGer RTA en6ine An a++ro+ria*e *9+e of

lurica*in6 oil 5us* e used for oil4lurica*ed +is*ons in order *o a7oid caron de+osi*s on *-e -o**er +ans of

*-e s9s*e5

,A/ B01 T-e L>0$& is a sin6le4ac*in6, lo34s+eed *3o4s*roBe re7ersile 5arine diesel en6ine5anufac*ured 9 $A !' I* is one of *-e $& series in*roduced in ./82, and -as a lon6er s*roBe and

increased 5axi5u5 +ressure 3-en co5+ared 3i*- *-e earlier L4(F and L4(! desi6nsT-e ed+la*e is 5ade of 3elded lon6i*udinal 6irders and 3elded cross 6irders 3i*- cas*4s*eel earin6

su++or*s :Fi6ure 22/; T-e fra5e ox is 5oun*ed on *-e ed+la*e and 5a9 e of cas* or 3elded desi6n On

*-e ex-aus* side of *-e en6ine a relief 7al7e and 5an-ole are +ro7ided for eac- c9linder On *-e ca5s-af*

side a lar6er -in6ed door is +ro7ided T-e c9linder fra5e uni*s 3-ic- co5+rise one or 5ore c9linders are of

cas* iron and ol*ed *o6e*-er *o for5 *-e reCuisi*e nu5er of en6ine c9linders To6e*-er 3i*- *-e c9linder

liners *-e9 for5 *-e sca7en6e air s+ace and *-e coolin6 3a*er s+ace T-e doule o**o5 in *-e sca7en6e

s+ace is 3a*er cooled T-e s*uffin6 ox fi**ed around *-e +is*on rod -as sealin6 rin6s *o s*o+ *-e leaBa6e of

sca7en6e air and scra+er rin6s *o +re7en* oil en*erin6 *-e sca7en6e s+ace

On *-e ca5s-af* side, access co7ers are +ro7ided for ins+ec*ion and cleanin6 of *-e sca7en6e s+ace T-e

c9linder co7er is a sin6le +iece 0. for6ed s*eel, and -as ored -oles for coolin6 3a*er circula*ion I* -as a

cen*ral o+enin6 for *-e ex-aus* 7al7es and a++ro+ria*e +ocBe*s for *-e fuel 7al7es, a relief 7al7e, a s*ar*in6 air

7al7e and *-e indica*or cocB T-e ex-aus* 7al7e -ousin6 is fi**ed in*o *-e cen*re of *-e c9linder -ead I* is

o+ened -9draulicall9 and closed 9 air +ressure Durin6 o+era*ion *-e ex-aus* 7al7e ro*a*es T-e ed+la*e,

fra5e ox and c9linder fra5es are connec*ed *o6e*-er 3i*- s*a9ol*s *o for5 *-e indi7idual uni*s Eac-

s*a9ol* is raced *o +re7en* *rans7erse oscilla*ions

T-e cranBs-af* 5a9 e solid or se5i4uil* on a c9linder 9 c9linder asis A s-af* +iece 3i*- a *-rus*collar is incor+ora*ed in*o *-e cranBs-af* and a* *-e af*er end -as a flan6e for *-e *urnin6 3-eel A* *-e

for3ard end a flan6e is fi**ed for *-e 5oun*in6 of a *unin6 de7ice or coun*er3ei6-*s

T-e runnin6 6ear consis*s of a +is*on, a +is*on rod and cross-ead asse5l9 and a for6ed s*eel connec*in6

rod T-e cross-ead 5o7es in 6uide s-oes 3-ic- are fi**ed on *-e fra5e ox ends T-e ca5s-af* -as se7eral


34/65

sec*ions, eac- of 3-ic- consis*s of a s-af* +iece 3i*- ex-aus* ca5s, fuel ca5s and cou+lin6s I* is dri7en 9 a

c-ain dri7e fro5 *-e cranBs-af*

Ex-aus* 6as fro5 *-e en6ine is +assed in*o a cons*an*4+ressure recei7er and *-en in*o *-e *uroc-ar6ers#ca7en6in6 is uniflo3, and elec*ricall9 dri7en auxiliar9 lo3ers are au*o5a*icall9 s*ar*ed durin6 lo34loado+era*ion

Lurica*in6 oil is su++lied *o *-e 7arious earin6s and also *o *-e +is*ons for coolin6 &9linder oil is

su++lied 7ia lurica*ors fro5 a -i6-4le7el ser7ice *anB A se+ara*e lurica*ion s9s*e5 is +ro7ided for *-e

ca5s-af* earin6s *o +re7en* con*a5ina*ion of *-e 5ain lurica*in6 oil s9s*e5 Fres- 3a*er coolin6 is

+ro7ided for *-e c9linder acBe*s, c9linder co7ers and ex-aus* 7al7es

T-e en6ine is desi6ned *o run on diesel oil or -ea79 fuel oil An elec*ronic 6o7ernor is +ro7ided as

s*andard


35/65

Pielstick

T-e Piels*icB P&series en6ines are sin6le4ac*in6, 5ediu54s+eed, four4s*roBe re7ersile *9+es !o*- in4line

and 4confi6ura*ions are a7ailale T-e runnin6 6ear, ein6 a *runB4*9+e en6ine, is 5ade u+ of *-e +is*on and*-e connec*in6 rod 3-ic- oins *-e sin6le4*-ro3 cranBs-af* T-e arran6e5en* of a P&@ en6ine is s-o3n in

Fi6ure 20

T-e cranBcase and fra5e are cons*ruc*ed fro5 -ea79 +la*e and s*eel cas*in6s *o +roduce a lo343ei6-* ri6id

s*ruc*ure T-e cranBs-af* is underslun6 and *-is arran6e5en* confines all s*resses *o *-e fra5e s*ruc*ure T-e

cranBs-af* is a one4+iece for6in6 and *-e connec*in6 rods are H4sec*ion s*eel s*a5+in6s T-e one4+iece

c9linder -ead con*ains *3o ex-aus* and *3o inle* 7al7es *o6e*-er 3i*- a s*ar*in6 air 7al7e, a relief 7al7e,

indica*or cocB and a cen*rall9 +osi*ioned fuel inec*or

Ex-aus*46as4dri7en *uro4c-ar6ers o+era*in6 on *-e +ulse s9s*e5 su++l9 +ressurised air *o *-e en6ine

c9linders

!earin6 lurica*ion and +is*on coolin6 are su++lied fro5 a co55on s9s*e5 T-e en6ine -as a dr9 su5+

3i*- oil suc*ion ein6 *aBen fro5 a se+ara*e *anB

T-e c9linder acBe*s are 3a*er4cooled *o6e*-er 3i*- *-e c9linder -eads and *-e ex-aus* 7al7e ca6es T-e

c-ar6e air cooler 5a9 e fres-43a*er or sea43a*er cooled as reCuired

Fuel inec*ion uses *-e erB +u5+ s9s*e5, and a 'ood3ard4*9+e -9draulic 6o7ernor is used *o con*rol

en6ine s+eed

La*er 7ersions of *-e P& series en6ine are descried as P&20 and P&@0 and -a7e so5e3-a* increased

scan*lin6s


36/65

'perating procedures

$ediu54 and slo34s+eed diesel en6ines 3ill follo3 a fairl9 si5ilar +rocedure for s*ar*in6 and 5anoeu7rin6

'-ere re7ersin6 6earoxes or

con*rollale4+i*c- +ro+ellers are used *-en en6ine re7ersin6 is no* necessar9 A 6eneral +rocedure is no3

6i7en for en6ine o+era*ion 3-ic- de*ails *-e 5ain +oin*s in *-eir correc* seCuence '-ere a 5anufac*urer Auxiliar9 sca7en6e lo3ers, if 5anuall9 o+era*ed, s-ould e s*ar*ed

8 T-e *urnin6 6ear is re5o7ed and if +ossile *-e en6ine s-ould e *urned o7er on air efore closin6 *-e

indica*or cocBs

/ T-e en6ine is no3 a7ailale for s*and9

T-e len6*- of *i5e in7ol7ed in *-ese +re+ara*ions 3ill de+end u+on *-e siGe of *-e en6ine

2ngine starting

. T-e direc*ion -andle is +osi*ioned a-ead or as*ern T-is -andle 5a9 e uil* in*o *-e *ele6ra+- re+l9

le7er T-e ca5s-af* is *-us +osi*ioned rela*i7e *o *-e cranBs-af* *o o+era*e *-e 7arious ca5s for fuel

inec*ion, 7al7e o+era*ion, e*c

2 T-e 5anoeu7rin6 -andle is 5o7ed .0


37/65

Chapter 3

Steam turbines and gearingT-e s*ea5 *urine -as un*il recen*l9 een *-e firs* c-oice for 7er9 lar6e +o3er 5ain +ro+ulsion uni*s I*s

ad7an*a6es of li**le or no 7ira*ion, lo3 3ei6-*, 5ini5al s+ace reCuire5en*s and lo3 5ain*enance cos*s are

considerale Fur*-er5ore a *urine can e +ro7ided for an9 +o3er ra*in6 liBel9 *o e reCuired for 5arine

+ro+ulsion Ho3e7er, *-e -i6-er s+ecific fuel consu5+*ion 3-en co5+ared 3i*- a diesel en6ine offse*s *-esead7an*a6es, al*-ou6- refine5en*s suc- as re-ea* -a7e narro3ed *-e 6a+

T-e s*ea5 *urine is a de7ice for o*ainin6 5ec-anical 3orB fro5 *-e ener69 s*ored in s*ea5 #*ea5

en*ers *-e *urine 3i*- a -i6- ener69 con*en* and lea7es af*er 6i7in6 u+ 5os* of i* T-e -i6-4+ressure s*ea5

fro5 *-e oiler is ex+anded in noGGles *o crea*e a -i6-47eloci*9 e* of s*ea5 T-e noGGle ac*s *o con7er* -ea*

ener69 in *-e s*ea5 in*o Bine*ic ener69 T-is e* is direc*ed in*o lades 5oun*ed on *-e +eri+-er9 01a 3-eel

or disc :Fi6ure .; T-e s*ea5 does no*


38/65

T-is is *-e o+era*in6 +rinci+le of all s*ea5 *urines, al*-ou6- *-e arran6e5en*s 5a9 7ar9 consideral9

T-e s*ea5 fro5 *-e firs* se* of lades *-en +asses *o ano*-er se* of noGGles and *-en lades and so on alon6

*-e ro*or s-af* un*il i* is finall9 ex-aus*ed Eac- se* co5+risin6 noGGle and lades is called a s*a6e

$urbinetypes

T-ere are *3o 5ain *9+es of *urine, *-e


39/65

*-e *urine casin6 T-is arran6e5en* +roduces a s-or* li6-*3ei6-* *urine 3i*- a +oorer efficienc9 3-ic-

3ould e acce+*ale in, for exa5+le, an as*ern *urine

T-e *3o arran6e5en*s 5a9 e co5ined *o 6i7e 3-a* is called


40/65

Curti!. An i5+ulse *urine 3i*- 5ore *-an one ro3 of lades *o eac- ro3 of noGGles, ie 7eloci*9co5+ounded

!e "aval. A -i6-4s+eed i5+ulse *urine 3-ic- -as onl9 one ro3 of noGGles and one ro3 of lades

#ateau. An i5+ulse *urine 3i*- se7eral s*a6es, eac- s*a6e ein6 a ro3 of noGGles and a ro3 of lades, ie

+ressure co5+ounded

Astern arrangements

$arine s*ea5 *urines are reCuired *o e re7ersile T-is is nor5all9 ac-ie7ed 9 *-e use of se7eral ro3s ofas*ern ladin6 fi**ed *o *-e -i6-4+ressure and lo34+ressure *urine s-af*s *o +roduce as*ern *urines Aou*10S of full +o3er is ac-ie7ed usin6 *-ese as*ern *urines '-en *-e *urine is o+era*in6 a-ead *-e as*ernladin6 ac*s as an air co5+ressor, resul*in6 in 3inda6e and fric*ion losses

Tur%ine construction

T-e cons*ruc*ion of an i5+ulse *urine is s-o3n in Fi6ure 1 T-e *urine ro*or carries *-e 7arious 3-eels

around 3-ic- are 5oun*ed *-e lades T-e s*ea5 decreases in +ressure as i* +asses alon6 *-e s-af* and

increases in 7olu5e reCuirin6 +ro6ressi7el9 lar6er lades on *-e 3-eels T-e as*ern *urine is 5oun*ed on

one end of *-e ro*or and is 5ac- s-or*er *-an *-e a-ead *urine

T-e *urine ro*or is su++or*ed 9 earin6s a* ei*-er endM one earin6 incor+ora*es a *-rus* collar *o resis* an9axial loadin6

T-e *urine casin6 co5+le*el9 surrounds *-e ro*or and +ro7ides *-e inle* and ex-aus* +assa6es for *-e

s*ea5 A* *-e inle* +oin* a noGGle ox is +ro7ided 3-ic- 9 use of a nu5er of noGGle 7al7es ad5i*s 7ar9in6

a5oun*s of s*ea5 *o *-e noGGles in order *o con*rol *-e +o3er de7elo+ed 9 *-e *urine T-e firs* se* ofnoGGles is 5oun*ed in a noGGle rin6 fi**ed in*o *-e casin6 Dia+-ra65s are circular +la*es fas*ened *o *-e

casin6 3-ic- are fi**ed e*3een *-e *urine 3-eels T-e9 -a7e a cen*ral circular -ole *-rou6- 3-ic- *-e ro*or

s-af* +asses T-e dia+-ra65s con*ain *-e noGGles for s*ea5 ex+ansion and a 6land is fi**ed e*3een *-e ro*or

and *-e dia+-ra65 T-e cons*ruc*ion of a reac*ion *urine differs so5e3-a* in *-a* *-ere are no dia+-ra65s

fi**ed and ins*ead fixed lades are loca*ed e*3een *-e 5o7in6 lades

4otor

T-e *urine ro*or ac*s as *-e s-af* 3-ic- *rans5i*s *-e 5ec-anical +o3er +roduced *o *-e +ro+eller s-af* 7ia

*-e 6earin6 I* 5a9 e a sin6le +iece 3i*- *-e 3-eels in*e6ral 3i*- *-e s-af* or uil* u+ fro5 a s-af* and

se+ara*e 3-eels 3-ere *-e di5ensions are lar6e

T-e ro*or ends adacen* *o *-e *urine 3-eels -a7e an arran6e5en* of raised rin6s 3-ic- for5 +ar* of *-e

la9rin*- 6land sealin6 s9s*e5, descried la*er in *-is c-a+*er Journal earin6s are fi**ed a* eac- end of *-ero*or T-ese -a7e rin6s arran6ed *o s*o+ oil *ra7ellin6 alon6 *-e s-af* 3-ic- 3ould 5ix 3i*- *-e s*ea5 One

end of *-e ro*or -as a s5all *-rus* collar for correc* lon6i*udinal ali6n5en* T-e o*-er end Has an a++ro+ria*e

flan6e or fi**in6 arran6ed for *-e flexile cou+lin6 3-ic- oins *-e ro*or *o *-e 6earox +inion

T-e lades are fi**ed in*o 6roo7es of7arious desi6ns cu* in*o *-e 3-eels


41/65

Blades

T-e s-a+in6 and *9+es of *urine lades -a7e alread9 een discussed '-en *-e *urine ro*or is ro*a*in6 a*

-i6- s+eed *-e lades 3ill e suec*ed *o considerale cen*rifu6al force and 7aria*ions in s*ea5 7eloci*9

across *-e lades 3ill resul* in lade 7ira*ion

Ex+ansion and con*rac*ion 3ill also occur durin6 *urine o+era*ion, *-ere a 5eans of fir5l9 securin6

*-e lades *o *-e 3-eel is essen*ial A of differen* desi6ns -a7e een e5+lo9ed :Fi6ure =;

T-e lades in7ol7es +lacin6 *-e lade roo* in*o *-e 3-eel

through a gate or entrance slot and sliding it into position. 'uccessive blades are fitted in turn and

the gate finally closed with a packing piece which is pinned into place. 'hrouding is then fitted

over tenons on the upper edge of the blades. Alternatively, lacing wires may be passed through

and bra7ed to all the blades.

2nd thrust

+n a reaction turbine a considerable axial thrust is developed. The closeness of moving parts in a

high-speed turbine does not permit any axial movement to take placeC the axial force or end thrust

must therefore be balanced out.

One 5e*-od of ac-ie7in6 *-is alance is *-e use of a du559 +is*on and c9linder A +i+e fro5 so5e s*a6e

in *-e *urine +ro7ides s*ea5 *o ac* on *-e du559 +is*on 3-ic- is 5oun*ed on *-e *urine ro*or :Fi6ure >;

T-e ro*or casin6 +ro7ides *-e c9linder *o enale *-e s*ea5 +ressure *o crea*e an axial force on *-e *urine

s-af* T-e du559 +is*on annular area and *-e s*ea5 +ressure are c-osen *o +roduce a force 3-ic- exac*l9

alances *-e end *-rus* fro5 *-e reac*ion ladin6 A *urine 3i*- a-ead and as*ern ladin6 3ill -a7e a

du559 +is*on a* ei*-er end *o ensure alance in ei*-er direc*ion of ro*a*ionAno*-er 5e*-od of*en used in lo34+ressure *urines is *o 5aBe *-e *urine doule flo3 'i*- *-is

arran6e5en* s*ea5 en*ers a* *-e cen*re of *-e s-af* and flo3s alon6 in o++osi*e direc*ions 'i*- an eCual

di7ision of s*ea5 *-e *3o reac*ion effec*s alance and cancelone ano*-er


42/65

lands and glandsealing

#*ea5 is +re7en*ed fro5 leaBin6 ou* of *-e ro*or -i6-4+ressure end and air is +re7en*ed fro5 en*erin6 *-e

lo34+ressure end 9 *-e use of 6lands A co5ina*ion of 5ec-anical 6lands and a 6land sealin6 s9s*e5 is

usual

$ec-anical 6lands are usuall9 of *-e la9rin*- *9+e A series of rin6s +roec*in6 fro5 *-e ro*or and *-e

casin6 co5ine *o +roduce a 5aGe of 3indin6 +assa6es or a la9rin*- :Fi6ure 8; An9 esca+in6 s*ea5 5us*

+ass *-rou6- *-is la9rin*-, 3-ic- reduces i*s +ressure +ro6ressi7el9 *o Gero

T-e 6land sealin6 s9s*e5 o+era*es in conunc*ion 3i*- *-e la9rin*- 6land 3-ere a nu5er of +ocBe*s are

+ro7ided T-e s9s*e5 o+era*es in one of *3o 3a9s

'-en *-e *urine is runnin6 a* full s+eed s*ea5 3ill leaB in*o *-e firs* +ocBe* and a +osi*i7e +ressure 3ill

e 5ain*ained *-ere An9 s*ea5 3-ic- fur*-er leaBs alon6 *-e s-af* *o *-e second +ocBe* 3ill e ex*rac*ed

9 an air +u5+ or air eec*or *o *-e 6land< s*ea5 condenser An9 air 3-ic- leaBs in fro5 *-e 5ac-iner9 s+ace

3ill also +ass *o *-e 6land s*ea5 condenser :Fi6ure /; A* 7er9 lo3 s+eeds or 3-en s*ar*in6 u+, s*ea5 is

+ro7ided fro5 a lo34+ressure su++l9 *o *-ein*er +ocBe*% T-e ou*er +ocBe* o+era*es as eforeT-e 6land s*ea5 sealin6 s9s*e5 +ro7ides *-e 7arious lo34+ressure s*ea5 su++lies and ex*rac*ion

arran6e5en*s for all *-e 6lands in *-e *urine uni*

)iaphragms

Onl9 i5+ulse *urines-a7e dia+-ra65s Dia+-ra65s are circular +la*es 5ade u+ of *3o se5i4circular -al7es

A cen*ral se5i4circular -ole 5 eac- is +ro7ided for *-e s-af* *o +ass *-rou6- T-e dia+-ra65 fi*s e*3een *-ero*or 3-eels and is fas*ened in*o *-e casin6 T-e noGGles are -oused in *-e dia+-ra65 around i*s +eri+-er9

T-e cen*ral -ole 5 *-e dia+-ra65 is arran6ed 3i*- +roec*ions *o +roduce a la9rin*- 6land around *-es-af*

/o..les


43/65

oGGles ser7e *o con7er* *-e -i6- +ressure and -i6- ener69 of *-e s*ea5 in*o a -i6-47eloci*9 e* of s*ea5

3i*- a reduced +ressure and ener69 con*en* T-e s*ea5 inle* noGGles are arran6ed in se7eral 6rou+s 3i*- all

u* *-e 5ain 6rou+ -a7in6 con*rol 7al7es :Fi6ure .0; In *-is 3a9 *-e +o3er +roduced 9 *-e *urine can

e 7aried, de+endin6 u+on -o3 5an9 noGGle con*rol 7al7es are o+ened !o*- i5+ulse and reac*ion *urines

-a7e s*ea5 inle* noGGles

Drains

Durin6 3ar5in6 *-rou6- o+era*ions or 3-en 5anoeu7rin6, s*ea5 3ill condense and collec* in 7arious +laces

3i*-in *-e *urine and i*s +i+elines A s9s*e5 of drains 5us* e +ro7ided *o clear *-is 3a*er a3a9 *o a7oid i*s

ein6 carried o7er in*o *-e lades, 3-ic- 5a9 do da5a6e LocaliGed coolin6 or dis*or*ion due *o une7en

-ea*in6 could also e caused

$odern ins*alla*ions no3 -a7e au*o5a*ic drain 7al7es 3-ic- o+en 3-en 3ar5in6 *-rou6- or

5anoeu7rin6 and close 3-en runnin6 a* nor5al s+eed

*earings

Turine earin6s are s*eel acBed, 3-i*e45e*al lined and su++or*ed in adus*ale -ousin6s *o allo3 ali6n5en*

c-an6es if reCuired T-rus* earin6s are of *-e *il*in6 +ad *9+e and are s+-ericall9 sea*ed T-e +ads are *-us

5ain*ained +arallel *o *-e collar and eCuall9 loaded De*ail of o*- *9+es can e seen in Fi6ure 1

Lurica*in6 oil en*ers a *urine earin6 *-rou6- a +or* on ei*-er side T-e en*r9 +oin* for *-e oil is

c-a5fered *o -el+ dis*riu*e *-e oil alon6 *-e earin6 o oil 3a9s are +ro7ided in *urine earin6s and a

6rea*er clearance e*3een earin6 and s-af* is +ro7ided co5+ared 3i*- a diesel en6ine T-e s-af* is ale *ofloa* on a 3ed6e of lurica*in6 oil durin6 *urine o+era*ion T-e oil lea7es *-e earin6 a* *-e *o+ and re*urns

*o *-e drain *anB

+u%ricating oil system

Lurica*in6 oil ser7es *3o func*ions in a s*ea5 *urine

. I* +ro7ides an oil fil5 *o reduce fric*ion e*3een 5o7in6 +ar*s 2 I* re5o7es -ea* 6enera*ed in *-e

earin6s or conduc*ed alon6 *-e s-af*

A co55on lurica*ion s9s*e5 is used *o su++l9 oil *o *-e *urine, 6earox and *-rus* earin6s and *-e

6ear s+ra9ers T-e *urine, ro*a*in6 a* -i6- s+eed, reCuires a considerale *i5e *o s*o+ i* 5e 5ain 5o*or

dri7en lurica*in6 oil +u5+s 3ere *o fail an e5er6enc9 su++l9 of lubricating oil would be necessary.


44/65

T-is is usuall9 +ro7ided fro5 a 6ra7i*9 *anB, al*-ou6- 5ain en6ine dri7en lurica*in6 oil +u5+s 5a9 also

e reCuired

A lurica*in6 oil s9s*e5 e5+lo9in6 o*- a 6ra7i*9 *anB and an en6ine dri7en +u5+ is s-o3n in Fi6ure

.. Oil is dra3n fro5 *-e drain *anB *-rou6- s*rainers and +u5+ed *o *-e coolers Lea7in6 *-e coolers, *-e

oil +asses *-rou6- ano*-er se* of fil*ers efore ein6 dis*riu*ed *o *-e 6earox, *-e *urine earin6s and *-e

6earox s+ra9ers #o5e of *-e oil also +asses *-rou6- an orifice +la*e and in*o *-e 6ra7i*9 *anB fro5 3-ic- i*

con*inuousl9 o7erflo3s :*-is can e oser7ed *-rou6- *-e si6-*6lass; T-e en6ine dri7en +u5+ su++lies a

+ro+or*ion of *-e s9s*e5 reCuire5en*s in nor5al o+era*ion

In *-e e7en* of a +o3er failure *-e 6earox s+ra9ers are su++lied fro5 *-e en6ine dri7en +u5+ T-e

6ra7i*9 *anB +ro7ides a lo34+ressure su++l9 *o *-e earin6s o7er a considerale +eriod *o enale *-e *urine

*o e rou6-* safel9 *o res*

2pansion arrangements

T-e 7aria*ion in *e5+era*ure for a *urine e*3een s*a*ionar9 and nor5al o+era*ion is considerale

Arran6e5en*s 5us* *-erefore e 5ade *o +er5i* *-e ro*or and casin6 *o ex+and

T-e *urine casin6 is usuall9 fixed a* *-e af*erend to a+edes*al su++or* or racBe*s fro5 *-e 6earox

T-e su++or* foot or+al5 on *-e casin6 is -eld securei9 a6ains* fore and af* 5o7e5en*, u* ecause of

elon6a*ed ol* -oles 5a9 5o7e side3a9s T-e for3ard su++or* +al5 -as si5ilar elon6a*ed -oles and 5a9

res* on a slidin6 foo* or +an*in6 +la*es Pan*in6 +la*es are 7er*ical +la*es 3-ic- can fiex or 5o7e axiali9 as

ex+ansion *aBes +lace

T-e for3ard +edes*al and *-e 6earcase racBe*s or af*er +edes*al su++or*s for *-e casin6 are fixed in

rela*ion *o one ano*-er T-e use of lar6e 7er*ical Be9s and slo*s on *-e su++or*s and casin6 res+ec*i7el9,

ensures *-a* *-e casin6 is Be+* cen*ral and in axial ali6n5en*

T-e ro*or is usuall9 fixed a* i*s for3ard end 9 *-e *-rus* collar, and an9 axial 5o7e5en* 5us* *-erefore

e *aBen u+ a* *-e 6earox end !e*3een *-e *urine ro*or and *-e 6earox is fi**ed a flexile cou+lin6 T-is

flexile cou+lin6 is ale *o *aBe u+ all axial 5o7e5en* of *-e ro*or as 3ell as correc* for an9 sli6-*

5isali6n5en*

An9 +i+es connec*ed *o *-e *urine casin6 5us* -a7e lar6e radiused ends or e fi**ed 3i*- ello3s

+ieces *o enale *-e casin6 *o 5o7e freel9 Also, an9 5o7e5en* of *-e +i+es due *o ex+ansion 5us* no*

affec* *-e casin6 T-is is usuall9 ensured 9 *-e use of flexile or s+rin6 su++or*s on *-e +i+es

'-en 3ar5in6 *-rou6- a *urine i* is i5+or*an* *o ensure *-a* ex+ansion is *aBin6 +lace freel9 arious

indica*ors are +ro7ided *o enale *-is *o e readil9 c-ecBed An9 slidin6 arran6e5en*s s-ould e Be+* cleanand 3ell lurica*ed

$urbine control

T-e 7al7es 3-ic- ad5i* s*ea5 *o *-e a-ead or as*ern *urines are Bno3n as


45/65

s9s*e5 failure

O+era*ion of *-e a-ead 5anoeu7rin6 7al7e 3ill ad5i* s*ea5 *o *-e 5ain noGGle ox Re5o*el9 o+era*ed

7al7es are used *o o+en u+ *-e re5ainin6 noGGle oxes for s*ea5 ad5ission as increased +o3er is reCuired A

s+eed4sensi*i7e con*rol de7ice ac*s on *-e a-ead 5anoeu7rin6 7al7e *o -old *-e *urine s+eed cons*an* a* *-e

desired 7alue

O+era*ion of *-e as*ern 5anoeu7rin6 7al7e 3ill ad5i* s*ea5 *o *-e 6uardian 7al7e 3-ic- is o+ened in

conunc*ion 3i*- *-e as*ern 7al7e #*ea5 is *-en ad5i**ed *o *-e as*ern *urines

Tur%ine protection

A *urine +ro*ec*ion s9s*e5 is +ro7ided 3i*- all ins*alla*ions *o +re7en* da5a6e resul*in6 fro5 an in*ernal

*urine faul* or *-e 5alfunc*ion of so5e associa*ed eCui+5en* Arran6e5en*s are 5ade in *-e s9s*e5 *o s-u*

*-e *urine do3n usin6 an e5er6enc9 s*o+ and solenoid 7al7e O+era*ion of *-is de7ice cu*s off *-e -9draulic

oil su++l9 *o *-e 5anoeu7rin6 7al7e and *-us s-u*s off s*ea5 *o *-e *urine T-is 5ain *ri+ rela9 is o+era*ed

9 a nu5er of 5ain faul* condi*ions 3-ic- are

. Lo3 lurica*in6 oil +ressure2 O7ers+eed

Lo3 condenser 7acuu5

@ E5er6enc9 s*o+1 Hi6- condensa*e le7el in condenser = Hi6- or lo3 oiler 3a*er le7el

O*-er faul* condi*ions 3-ic- 5us* e 5oni*ored and for5 +ar* of a *o*al +ro*ec*ion s9s*e5 are

. HP and LP ro*or eccen*rici*9 or 7ira*ion

2 HP and LP *urine differen*ial ex+ansion, ie ro*or 3i*- res+ec* *o casin6 HP and LP *-rus* earin6 3eardo3n@ $ain *-rus* earin6 3eardo3n

1 Turnin6 6ear en6a6ed :*-is 3ould +re7en* s*ar*in6 of *-e *urine;

#uc- 10

re7?5in T-e es* +ro+eller s+eed for efficien* o+era*ion is in *-e re6ion of 80 *o .00 re7?5in T-e *urine or

en6ine s-af* s+eed is reduced *o *-a* of *-e +ro+eller 9 *-e use of a s9s*e5 of 6earin6 Helical 6ears -a7e

een used for 5an9 9ears and re5aU V san of 5os* s9s*e5s of 6earin6 E+ic9clic 6ears 3i*- *-eir co5+ac*,

li6-*3ei6-*, cons*ruc*ion are ein6 increasin6l9 used in 5arine *rans5issions

2picyclic gearing T-is is a s9s*e5 of 6ears 3-ere one or 5ore 3-eels *ra7el around *-e ou*side or

inside of ano*-er 3-eel 3-ose axis is fixed T-e differen* arran6e5en*s are Bno3n as +lane*ar9 6ear, solar

sear and s*ar o4ear :Fi6ure .2;

T-e 3-eelon the+rinci+alais iscalled *-e sun 3-eel T-e 3-eel 3-ose cen*re re7ol7es around *-e+rinci+al axis is *-e +lane* 3-eel An in*ernal4*ee*- 6ear 3-ic- 5es-es 3i*- *-e +lane* 3-eel is called *-e

annulus T-e differen* arran6e5en*s of fixed ar5s and siGin6 of *-e sun and +lane* 3-eels +ro7ide a 7arie*9

of differen* reduc*ion ra*ios


46/65

#*ea5 *urine rearin6 5a9 e doule or *ri+le reduc*ion and 3ill e a co5ina*ion fro5 in+u* *o ou*+u* of

s*ar and +lane*ar7 5odes in conunc*ion 3i*- -elical 6earin6 :Fi6ure .;5elicalgearing

#in6le or doule reduc*ion s9s*e5s 5a9 e used, al*-ou6- doule reduc*ion is 5ore usual 'i*- sin6le

reduc*ion *-e *urine dri7es a +inion 3i*- a s5all nu5er of *ee*- and *-is +inion dri7es *-e 5ain 3-eel

3-ic- is direc*l9 cou+led *o *-e +ro+eller s-af* 'i*- doule reduc*ion *-e *urine dri7es a +ri5ar9 +inion

3-ic- dri7es< a +ri5ar9 3-eel T-e +ri5ar9 3-eel dri7es, on *-e sa5e s-af*, a secondar9 +inion 3-ic- dri7es

*-e 5ain 3-eel T-e 5ain 3-eel is direc*l9 cou+led *o *-e +ro+eller s-af* A doule reduc*ion 6earin6 s9s*e5

is s-o3n in Fi6ure .@

All 5odern 5arine 6earin6 is of *-e doule -elical *9+e Helical 5eans *-a* *-e *ee*- for5 +an of a -elix on

*-e +eri+-er9 of *-e +inion or 6ear 3-eel T-is 5eans *-a* a* an9 *i5e se7eral *ee*- are in con*ac* and *-us *-e

s+read and *ransfer of load is 5uc- s5oo*-er Doule -elical refers *o *-e use of *3o 3-eels or +inions on

eac- s-af* 3i*- *-e *ee*- cu* in o++osi*e direc*ions T-is is ecause a sin6le se* of 5es-in6 -elical *ee*- 3ould

+roduce a side3a9s force, 5o7in6 *-e 6ears ou* of ali6n5en* T-e doule se* in effec*


47/65

alances ou* *-is side3a9s force T-e 6earin6 s9s*e5 s-o3n in Fi6ure .@ is doule -elical

Lurica*ion of *-e 5es-in6 *ee*- is fro5 *-e *urine lurica*in6 oil su++l9 #+ra9ers are used *o +roec*

oil a* *-e 5es-in6 +oin*s o*- ao7e and elo3 and are arran6ed alon6 *-e len6*- of *-e 6ear 3-eel

"leible coupling

A flexile coun*in6 is al3a9s fi**ed e*3een *-e *urine ro*or and *-e 6earox +inion I* +er5i*s sli6-*ro*or andpinion 5isali6n5en* as 3ell as allo3in6 for axial 5o7e5en* of *-e ro*or due *o ex+ansion ariousdesi6ns of flexile cou+lin6 are in use usin6 *ee*-, flexile cou+lin6 are in use usin6 *ee*-, flexile discs,5e5ranes, e*c

T-e 5e5rane4*9+e flexile cou+lin6 s-o3n in Fi6ure .1 is 5ade u+ of a *orCue *ue, 5e5ranes andada+*or +la*es T-e *orCue *ue fi*s e*3een *-e *urine ro*or and *-e 6earox +inion T-e ada+*or +la*es ares+i6o*ed and do3elled on*o *-e *urine and +inion flan6es and *-e 5e5rane +la*es are ol*ed e*3een *-e*orCue *ue and *-e ada+*or +la*es T-e flexin6 of *-e 5e5rane +la*es enales axial and *rans7erse5o7e5en* *o *aBe +lace T-e *orCue *ue en*ers *-e ada+*or +la*e 3i*- a clearance 3-ic- 3ill +ro7ide ane5er6enc9 cen*rin6 s-ould *-e 5e5ranes fail T-e ol*s in *-eir clearance -oles 3ould +ro7ide *-econ*inuin6 dri7e un*il *-e s-af* could e s*o++ed

Turning gear T-e *urnin6 6ear on a *urine ins*alla*ion is a re7ersile elec*ric 5o*or dri7in6 a 6ear3-eel 3-ic- 5es-es

in*o *-e -i6-4+ressure *urine +ri5ar9 +inion I* is used for 6ear3-eel and *urine ro*a*ion durin6

5ain*enance or 3-en 3ar5in6 *-rou6- +rior*o 5anoeu7rin6


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Operating procedures

T-e s*ea5 *urine reCuires a considerale +eriod for 3ar5in64*-rou6- +rior *o an9 5anoeu7rin6 *aBin6

+lace T-e -i6-4s+eed o+era*ion of *-e *urine and i*s si5+l9 su++or*ed ro*or also reCuire 6rea* care durin65anoeu7rin6 o+era*ions

,arming-through a steam tur%ine

Firs* o+en all *-e *urine4casin6 and 5ain s*ea54line drain 7al7es and ensure *-a* all *-e s*ea5 con*rol

7al7es a* *-e 5anoeu7rin6 s*a*ion and around *-e *urine are closed All led s*ea54line drain 7al7es s-ould

e o+ened #*ar* *-e lurica*in6 oil +u5+ and see *-a* *-e oil is flo3in6 freel9 *o eac- earin6 and 6ear

s+ra9er, 7en*in6 off air if necessar9 and c-ecB *-a* *-e 6ra7i*9 *anB is o7erflo3in6

O*ain clearance fro5 *-e rid6e *o *urn *-e s-af* En6a6e *-e *urnin6 6ear and ro*a*e *-e *urines in eac-

direc*ion

#*ar* *-e sea 3a*er circula*in6 +u5+ for *-e 5ain condenser T-en s*ar* *-e condensa*e ex*rac*ion +u5+

3i*- *-e air eec*or recircula*ion 7al7e 3ide o+en O+en *-e 5anoeu7rin6 7al7e 9+ass or 1& is reac- d a* *-e LP *urine inle* af*er aou* one -our T-e

ex+ansion arran6e5en*s on *-e *urine *o allo3 freedo5 of 5o7e5en* s-ould e c-ecBed

(land sealin6 s*ea5 s-ould no3 e +ar*iall9 o+ened u+ and *-e 7acuu5 increased T-e *urnin6 6ear s-ould

no3 e disen6a6ed

#-or* las*s of s*ea5 are no3 ad5i**ed *o *-e *urine *-rou6- *-e 5ain 7al7e *o s+in *-e +ro+eller aou* one

re7olu*ion T-is s-ould e re+ea*ed aou* e7er9 *-ree *o fi7e 5inu*es for a +eriod of .1 *o 0 5inu*es T-e

7acuu5 can no3 e raised *o i*s o+era*ional 7alue and also *-e 6land s*ea5 +ressure T-e *urines are no3

read9 for use

'-ile 3ai*in6 for *-e firs* 5o7e5en*s fro5 *-e rid6e, and e*3een 5o7e5en*s, *-e *urine 5us* e

*urned a-ead once e7er9 fi7e 5inu*es 9 s*ea5 las*s If *-ere is an9 dela9 6land s*ea5 and *-e 7acuu5

s-ould e reducedManoeuvring

Once 3ar5ed *-rou6-, *-e *urine ro*or 5us* no* re5ain s*a*ionar9 5ore *-an a fe3 5inu*es a* a *i5eecause *-e ro*or could sa6 or dis*or*, 3-ic- 3ould lead *o failure, if no* re6ularl9 ro*a*ed

As*ern o+era*ion in7ol7es ad5i**in6 s*ea5 *o *-e as*ern *urines '-ere an9 considerale +eriod of as*ern

runnin6 occurs *urine *e5+era*ures, noise le7els, earin6s, e*c, 5us* e closel9 oser7ed T-e *urine

5anufac*urer 5a9 se* a *i5e li5i*of aou* 0 5inu*es on con*inuous runnin6 as*ern

2mergency astern operation

If, 3-en *ra7ellin6 a* full s+eed a-ead, an order for an e5er6enc9 s*o+ or as*ern 5o7e5en* is reCuired *-en

safe o+era*in6 +rocedures 5us* e i6nored A-ead s*ea5 is s-u* off, +roal9 9 *-e use of an e5er6enc9

*ri+, and *-e as*ern s*ea5 7al7e is +ar*l9 o+ened *o ad5i* a 6raduall9 increasin6 a5oun* of s*ea5 T-e *urine

can *-us e rou6-* CuicBl9 *o a s*o++ed condi*ion and if reCuired can *-en e o+era*ed as*ern

T-e s*o++in6 of *-e *urine or i*s as*ern o+era*ion 3ill occur aou* .0 *o .1 5inu*es efore a si5ilar s*a*e

3ill occur for *-e s-i+ T-e use o e5er6enc9 +rocedures can lead *o serious da5a6e in *-e *urine, 6earox

or boilers.


49/65

Full away$anoeu7rin6 re7olu*ions are usuall9 aou* 80S of *-e full a3a9 or full s+eed condi*ion Once *-e full a3a9

co55and is recei7ed *-e *urine can 6raduall9 e rou6-* u+ *o full +o3er o+era*ion, a +rocess *aBin6 one

*o *3o -ours T-is 3ill also in7ol7e rin6in6 in*o use *uro4al*erna*ors 3-ic- use s*ea5 re5o7ed or


50/65


51/65

+rocess is 5uc- CuicBer Desi6n arran6e5en*s are flexile, efficienc9 is -i6- and *-e feed3a*er -as a 6ood

na*ural circula*ion T-ese are so5e of *-e 5an9 reasons 3-9 *-e 3a*er4*ue oiler -as re+laced *-e fire*ue

oiler as *-e 5aor s*ea5 +roducer

Earl9 3a*er*ue oilers used a sin6le dru5 Headers 3ere connec*ed *o *-e dru5 9 s-or*, en* +i+es

3i*- s*rai6-* *ues e*3een *-e -eaders T-e -o* 6ases fro5 *-e furnace +assed o7er *-e *ues, of*en in a

sin6le +ass

A la*er de7elo+5en* 3as *-e en* *ue desi6n T-is oiler -as *3o dru5s, an in*e6ral furnace and is of*enreferred *o as *-e


52/65

T-ese +ro7ide *-e 5ain -ea* *ransfer surfaces for s*ea5 6enera*ion Lar6e4ore +i+es or do3nco5ers are

fi**ed e*3een *-e s*ea5 and 3a*er dru5 *o ensure 6ood na*ural circula*ion of *-e 3a*er In *-e

arran6e5en* s-o3n, *-e su+er-ea*er is loca*ed e*3een *-e %urns, +ro*ec*ed fro5 *-e 7er9 -o* furnace

6ases 9 se7eral ro3s 0. screen *ues Refrac*or9 5a*erial or ricB3orB is used on *-e furnace floor *-e

urner 3all and also e-ind *-e 3a*er3alls T-e doule casin6 o *-e oiler +ro7ides a +assa6e for *-e

co5us*ion air *o *-e air con*rol or re6is*er surroundin6 *-e urner

The need for a wider range of superheated steam temperature control led to other boilerarrangements being used. The original !xternal 'uperheater &)& !')0 type of boiler used aprimary and secondary superheater located after the main generating tube bank igure $.%0. Anattemperator located in the combustion air path was used .Dcontrol the steam temperature.

The later !') ++ type boiler was similar in construction to the !') + but used a control unit an

additional economi7er0 between the primary and secondary superheaters. 8inked dampers

directed the hot gases over the control unit or the superheater depending upon the superheat

temperature required. The control unit provided a bypass path for the gases when low temperature

superheating was required.

+n the !') +++ boiler the burners are located in the furnace roof , which provides a long flame

path and even heat transfer throughout the furnace. +n the boiler shown in igure $.$, the furnace

is fully water-cooled and of monowall construction, which is produced from finned tubes welded

together to form a gastight casing. 5ith monowall construction no refractory material is necessary

in the furnace.

The furnace side, floor and roof tubes are welded into the steam and water drums. The front and

rear walls are connected at either end to upper and lower water-wall headers. The lower water-wall

headers are connected by external downcomers from the steam drum and the upper water-wall

headers are connected to the steam drum by riser tubes.

The gases leaving the furnace pass through screen tubes which are arranged to permit flowbetween them. The large number of tubes results in considerable heat transfer before the gases

reach the secondary superheater. The gases then flow over the primary superheater and the

economi7er before passing to exhaust. The dry pipe is located in the steam drum to obtain

reasonably dry saturated steam from the boiler. This is then passed to the primary superheater and


53/65

*-en *o *-e secondar9 su+er-ea*er #*ea5 *e5+era*ure con*rol is ac-ie7ed 9 *-e use of an a**e5+era*or,

loca*ed in *-e s*ea5 dru5, o+era*in6 e*3een *-e +ri5ar9 and secondar9 su+er-ea*ers

Radian*4*9+e oilers area 5ore recen* de7elo+5en*6in 3-ic- *-e radian -ea* of co5us*ion is asored*o raise s*ea5, ein6 *rans5i**er 9 infra4red radia*ion T-is usuall9 reCuires roof firin6 and a considerale-ei6-* in order *o func*ion efficien*l9 T-e E#D I oiler s-o3n in Fi6ure @1 is of *-e radian* *9+e !o*- *-e

furnace and *-e ou*er c-a5er are full9 3a*er4cooled

T-ere is no con7en*ional anB of 6enera*in6 *ues T-e -o* 6ases lea7e *-e furnace *-rou6-an o+enin6 a* *-e lo3er end of *-e screen 3all and +ass *o *-e ou*er c-a5er T-e ou*er c-a5er con*ains *-e

con7ec*ion -ea*in6 surfaces 3-ic- include *-e +ri5ar9 and secondar9 su+er-ea*ers #u+er-ea* *e5+era*urecon*rol is 9 5eans of an a**e5+era*or in *-e s*ea5 dru5 T-e -o* 6ases, af*er lea7in6 *-e +ri5ar9su+er-ea*er, +ass o7er a s*ea5in6 econo5iser T-is is a -ea* exc-an6er in 3-ic- *-e s*ea53a*er 5ix*ure is

flo3in6 +arallel *o *-e 6as T-e furnace 6ases finall9 +ass o7er a con7en*ional econo5iser on *-eir 3a9 *o *-efunnel

Re-ea* oilers are used 3i*- re-ea* arran6ed *urine s9s*e5s #*ea5 af*er ex+ansion in *-e -i6-4+ressure

*urine is re*urned *o a re-ea*er in *-e oiler Here *-e s*ea5 ener69 con*en* is raised efore i* is su++lied *o

*-e lo34+ressure *urine Re-ea* oilers are ased on oiler desi6ns suc- as *-e


54/65

T-e 5ono3all cons*ruc*ion eli5ina*es *-e +role5s of refrac*or9 and ex+anded oin*s Ho3e7er, in *-e

e7en* of *ue failure, a 3elded re+air 5us* e carried ou* Al*erna*i7el9 *-e *ue can e +lu66ed a* ei*-er

end, u* refrac*or9 5a*erial 5us* e +laced o7er *-e failed *ue *o +ro*ec* *-e insula*ion e-ind i* 'i*-

*an6en* *ue cons*ruc*ion a failed *ue can e +lu66ed and *-e oiler o+era*ed nor5all9 3i*-ou* fur*-er

a**en*ion

Firetu%e %oiler T-e fire*ue oiler is usuall9 c-osen for lo34+ressure s*ea5 +roduc*ion on 7esselsreCuirin6 s*ea5 for auxiliar9 +ur+oses O+era*ion is si5+le and feed3a*er of 5ediu5 Cuali*9 5a9 ee5+lo9ed T-e na5e *anB oiler is so5e*i5es used for fire*ue oilers ecause of *-eir lar6e 3a*er

ca+aci*9 T-e *er5s s5oBe *ue< and donBe9 oiler are also 5 use

Package boilers $os* fire*ue oilers are no3 su++lied as a co5+le*el9 +acBa6ed uni* T-is 3ill include

*-e oil urner, fuel +u5+, forced Q drau6-* fan, feed +u5+s and au*o5a*ic con*rols for *-e s9s*e5 T-e oiler3ill e fi**ed 3i*- all *-e a++ro+ria*e oiler 5oun*in6s

A sin6le4furnace *-ree4+ass desi6n is s-o3n in Fi6ure @> T-e firs*+ass is *-rou6- *-e +ar*l9 corru6a*edfurnace and in*o *-e c9lindrical 3e*acB co5us*ion c-a5er T-e second +ass is acB o7er *-e furnace

*-rou6- s5all4ore s5oBe *ues and *-en *-e flo3 di7ides a* *-e fron* cen*ral s5oBe ox T-e *-ird +ass is

*-rou6- ou*er s5oBe *ues *o *-e 6as exi* a* *-e acB of *-e oiler T-ere is no co5us*ion c-a5er

refrac*or9 linin6 o*-er *-an a linin6 *o *-e co5us*ion c-a5er access door and *-e +ri5ar9 and secondar9


55/65

Cuarl

Full9 au*o5a*ic con*rols are +ro7ided and loca*ed in a con*rol +anel a* *-e side of *-e oilerCochran boilers

T-e 5odern 7er*ical &oc-ran oiler -as a full9 s+-erical furnace and is Bno3n as *-e


56/65

in Fi6ure@/

Double e)aporation boilers

A doule e7a+ora*ion oiler uses *3o inde+enden* s9s*e5s for s*ea5 6enera*ion and *-erefore a7oids an9

con*a5ina*ion e*3een *-e +ri5ar9 and secondar9 feed3a*er T-e +ri5ar9 circui* is in effec* a

con7en*ional 3a*er*ue oiler 3-ic- +ro7ides s*ea5 *o *-e -ea*in6 coils of a s*ea54*o4s*ea5 6enera*or,

3-ic- is *-e secondar9 s9s*e5 T-e co5+le*e oiler is enclosed in a +ressurised casin6

#haust gas heat echangers

T-e use of ex-aus* 6ases fro5 diesel 5ain +ro+ulsion en6ines *o 6enera*e s*ea5 is a 5eans of -ea* ener69

reco7er9 and i5+ro7ed +lan* efficienc9

An ex-aus* 6as -ea* exc-an6er is s-o3n in Fi6ure @.0 I* is si5+l9 a ro3 of *ue anBs circula*ed 9

feed3a*er o7er 3-ic- *-e ex-aus* 6ases flo3 Indi7idual anBs 5a9 e arran6ed *o +ro7ide feed -ea*in6,

s*ea5 6enera*ion and su+er-ea*in6 A oiler dru5 is reCuired for s*ea5 6enera*ion and se+ara*ion *o *aBe

+lace and use is usuall9 5ade of *-e dru5 of an auxiliar9 oiler.

Auiliarysteam plant system

T-e auxiliar9 s*ea5 ins*alla*ion +ro7ided in 5odern diesel +o3ered *anBers usuall9 uses an ex-aus*

6as -ea* exc-an6er a* *-e ase of *-e funnel and one or +er-a+s *3o 3a*er*ue oilers :Fi6ure @.0;

#a*ura*ed or su+er-ea*ed s*ea5 5a9 e o*ained fro5 *-e auxiliar9 oiler A* sea i* ac*s as a s*ea5

recei7er for *-e ex-aus*46as -ea* exc-an6er, 3-ic- is circula*ed *-rou6- i* In +or* i* is oil4fired in *-e

usual 3a9

2haust gas boilers

Auxiliar9 oilers on diesel 5ain +ro+ulsion s-i+s, o*-er *-an *anBers, are usuall9 of co5+osi*e for5,

enalin6 s*ea5 6enera*ion usin6 ol firin6 or *-e ex-aus* 6ases fro5 *-e diesel en6ine 'i*- *-is arran6e5en*

*-e oiler ac*s as *-e -ea* exc-an6er and raises s*ea5 in i*s o3n dru5

Boiler mountings


57/65

&er*ain fi**in6s are necessar9 on a oiler *o ensure i*s safe o+era*ion T-e9 are usuall9 referred *o as oiler

5oun*in6s T-e 5ounur44s usuall9 found on a oiler are

Safet& valves.T-ese are 5oun*ed in +airs *o +ro*ec* *-e oiler a6ains* o7er+ressure Once *-e 7al7e lif*in6

+ressure is se* in *-e +resence o a #ur7e9or i* is locBed and canno* e c-an6ed T-e 7al7e is arran6ed *o o+en

au*o5a*icall9 a* *-e +re4se* lo34off +ressure

'ain steam stop valve.T-is 7al7e is fi**ed in *-e 5ain s*ea5 su++l9 line and is usuall9 of *-e non4re*urn

*9+eAu(iliar& steam stop valve.T-is is a s5aller 7al7e fi**ed in *-e auxiliar9 s*ea5

Documents

Marine Engineering Part1[1]