combustion engine wpracticum report

7/25/2019 Combustion Engine WPracticum Report

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INSTITUT TEKNOLOGI SEPULUH

NOPEMBERFACULTY OF MARINE TECHNOLOGYDD - MARINE ENGINEERING

ALFA MUHAMMAD MEGAWAN 4213101020

PEMAL SARAGE 4214101038NOOR FAZRUR RR 4214101023TITUS KURNIAWAN 421410102!RAIHAN DZAKY - 4214101441


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CHAPTER IINTRODUCTION

11 B"#$%&'()*

The diesel engine is a type of internal combustion engine (internalcombustion engine) , more details again is triggered compressionengines , where fuel will be ignited by the high temperature gas that hasbeen compressed , not with other instruments such as spark plugsenergized . Diesel engines are generally in use on cars that have a largecapacity engine and power are great . Diesel engines used in cars becausediesel engines are very suitable for long distance travel , because thediesel engine is more resistant recom compared with gasoline engines ,diesel engines also have more power than gasoline engines because it hasa construction machine big and strong.

Diesel fuel generally is any li!uid fuel used for diesel engines . Themost common types of fuel oil derived from the distillation of petroleumfractions , but there are also products other than petroleum derivativessuch as biodiesel , diesel biomass into a li!uid or gas into li!uid diesel . Todistinguish the types of diesel fuel from petroleum generally calledpetrodiesel . Diesel with ultra " low sulfur ( #$%D ) is a standard forde&ning diesel fuel with a sulfur content that has been debased .

The purpose of the fuel combustion is to obtain energy calledthermal energy (heat energy). 'esults burning fuel that can be in the formof heat energy into other energy forms, for eample energy for lighting,mechanical energy and so on. Thus any burning fuel results will be

obtained some other form of energy that can be ad*usted to such needs.

12 P(&+',, '. P&"#/#(+. nowing chart of %- /s 0ower.1. nowing chart /s 0ower.2. nowing chart full load power /s rpm.3. nowing chart full load tor!ue /s rpm.4. nowing chart 5670 /s rpm.8. nowing diagram engine an envelope.

13 O#/, '. P&"#/#(+. The students know how diesel engine work.1. The students know the di9erences from di9erent oil for diesel

engine.2. The students know the e9ect from load to diesel engine:s rpm.3. The students know the usage of diesel engine.


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CHAPTER IIBASIC THEORY

;n +


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p/ diagram

The p"/ diagram is a simpli&ed and idealised representation of the

events involved in a Diesel engine cycle, arranged to illustrate the

similarity with a arnot cycle. %tarting at +, the piston is at bottom dead

centre and both valves are closed at the start of the compression strokeC

the cylinder contains air at atmospheric pressure. 5etween + and 1 the air

is compressed adiabaticallyEthat is without heat transfer to or from the

environmentEby the rising piston. (This is only approimately true since

there will be some heat echange with the cylinder walls.) During this

compression, the volume is reduced, the pressure and temperature both

rise. >t or slightly before 1 (TD) fuel is in*ected and burns in the

compressed hot air. hemical energy is released and this constitutes an

in*ection of thermal energy (heat) into the compressed gas. ombustion

and heating occur between 1 and 2. ;n this interval the pressure remains

constant since the piston descends, and the volume increasesC the

temperature rises as a conse!uence of the energy of combustion. >t 2 fuel

in*ection and combustion are complete, and the cylinder contains gas at a

higher temperature than at 1. 5etween 2 and 3 this hot gas epands,

again approimately adiabatically. Fork is done on the system to which

the engine is connected. During this epansion phase the volume of the

gas rises, and its temperature and pressure both fall. >t 3 the ehaust

valve opens, and the pressure falls abruptly to atmospheric

(approimately). This is unresisted epansion and no useful work is done

by it. ;deally the adiabatic epansion should continue, etending the line
https://en.wikipedia.org/wiki/Carnot_cyclehttps://en.wikipedia.org/wiki/Carnot_cycle


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2"3 to the right until the pressure falls to that of the surrounding air, but

the loss of e?ciency caused by this unresisted epansion is *usti&ed by

the practical di?culties involved in recovering it (the engine would have

to be much larger). >fter the opening of the ehaust valve, the ehauststroke follows, but this (and the following induction stroke) are not shown

on the diagram. ;f shown, they would be represented by a lowpressure

loop at the bottom of the diagram. >t + it is assumed that the ehaust and

induction strokes have been completed, and the cylinder is again &lled

with air. The pistoncylinder system absorbs energy between + and 1Ethis

is the work needed to compress the air in the cylinder, and is provided by

mechanical kinetic energy stored in the Gywheel of the engine. Fork

output is done by the pistoncylinder combination between 1 and 3. The

di9erence between these two increments of work is the indicated work

output per cycle, and is represented by the area enclosed by the p"/ loop.

The adiabatic epansion is in a higher pressure range than that of the

compression because the gas in the cylinder is hotter during epansion

than during compression. ;t is for this reason that the loop has a &nite

area, and the net output of work during a cycle is positive.

;n diesel engines, conditions in the engine di9er from the spark

ignition engine, since power is directly controlled by the fuel supply,

rather than by controlling the air supply.

The average diesel engine has a poorer powertoweight ratio than

the petrol engine. This is because the diesel must operate at lower engine

speed and because it needs heavier, stronger parts to resist the operatingpressure caused by the high compression ratio of the engine and the large

amounts of tor!ue generated to the crankshaft. ;n addition, diesels are

often built with stronger parts to give them longer lives and better

reliability, important considerations in industrial applications.

Diesel engines usually have longer stroke lengths chieGy to facilitate

achieving the necessary compression ratios, but also to reduce the

optimal operating speed (rpm). >s a result, piston and connecting rods are
https://en.wikipedia.org/wiki/Petrol_enginehttps://en.wikipedia.org/wiki/Petrol_engine


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heavier and more force must be transmitted through the connecting rods

and crankshaft to change the momentum of the piston. This is another

reason that a diesel engine must be stronger for the same power output

as a petrol engine.

Het it is this characteristic that has allowed some enthusiasts to

ac!uire signi&cant power increases with turbochargedengines by making

fairly simple and inepensive modi&cations. > petrol engine of similar size

cannot put out a comparable power increase without etensive alterations

because the stock components cannot withstand the higher stresses

placed upon them. %ince a diesel engine is already built to withstand

higher levels of stress, it makes an ideal candidate for performance

tuningat little epense. =owever, it should be said that any modi&cation

that raises the amount of fuel and air put through a diesel engine will

increase its operating temperature, which will reduce its life and increase

service re!uirements. These are issues with newer, lighter, high-

performancediesel engines which are not AoverbuiltA to the degree of

older engines and they are being pushed to provide greater power in

smaller engines.

The -ormula to calculate the 7ngine:s 0ower

P=V x i

Load Factor

0I 0ower (Fatt)

/ I /oltage (/olt)i I 7lectric urrent (>mpere)

Diesel engines produce more tor!ue than petrol engines for a givendisplacement due to their higher compression ratio. =igher pressure in thecylinder and higher forces on the connecting rods and crankshaft re!uirestronger, heavier components. =eavier rotating components preventdiesel engines from reving as high as petrol engines for a givendisplacement. Diesel engines generally have similar power and inferiorpower to weight to petrol engines. 0etrol engines must be geared lower toget the same tor!ue as a comparable diesel but since petrol engines revhigher both will have similar acceleration. >n arbitrary amount of tor!ue
https://en.wikipedia.org/wiki/Turbochargerhttps://en.wikipedia.org/wiki/Engine_tuninghttps://en.wikipedia.org/wiki/Engine_tuninghttps://en.wikipedia.org/wiki/Turbochargerhttps://en.wikipedia.org/wiki/Engine_tuninghttps://en.wikipedia.org/wiki/Engine_tuning


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at the wheels can be gained by gearing any power source downsu?ciently (including a hand crank).

The onnection between 0ower and Tor!ue on the 7ngine P=2 x Rps x T

0I 0ower (Fatt)'ps I 'ound per secondTI Tor!ue (J.m)

The term 5670 is an engineering term that means 5rake 6ean79ective 0ressure. 6ean is another word for average, which in this casemeans average e9ective pressure of all stroke cycles. This is used toevaluate all engines whether they are Two or -our ycle. 5670 is afunction of temperature of the gases in the cylinder. To increase thetemperature you need to burn more fuel, thus making more heat. ranother way is to make better use of the eisting fuel. Tor!ue is a function

of 5670 and displacement only. =0 is a function of tor!ue and rpm.;t is said a high 5670 and a low rpm, or a low 5670 and a high rpm,

can e!ual the same power. $arger valves, ports, pipes, compression, etc.all come into play to increase the volumetric e?ciency of the engine. Themost e9ective is to increase the number of cylinders. The more e?cient itis, the higher the average pressure or 5670.

0ressure increases by compression alone can do wonders to a stockengine, it is, by factory choice, usually a low number. Jote that aftercompression gets very high it starts to work against you in pumpinglosses, and in the amount of heat lost to the surrounding parts.

The onnection between 0ower and 5670 on the 7ngine P=i x BMEP x L x A x zx Rps

5670 I 5rake 6ean 79ective 0ressure. 0 I 0ower (Fatt) K I The number of cylinder i I + for 1strokes $ I 0iston displacement i I L.4 for 3strokes > I ross section of cylinder T I Tor!ue (J.m) 'ps I 'ound per second

DieselBs original engine in*ected fuel with the assistance ofcompressed air, which atomized the fuel and forced it into the enginethrough a nozzle (a similar principle to an aerosol spray). The nozzleopening was closed by a pin valve lifted by the camshaft to initiate thefuel in*ection before top dead centre (TD). This is called an "&-5",/)#/'). Driving the three stage compressor used some power but thee?ciency and net power output was more than any other combustionengine at that time.
https://en.wikipedia.org/wiki/Top_Dead_Centerhttps://en.wikipedia.org/wiki/Top_Dead_Center


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CHAPTER IIITHE E6ECUTION OF PRACTICUM

31 P5"# ")* D"/ '. P&"#/#(This practicum divided into 1 sessions which held on Jovember 4th

1L+4 and Jovember Mth 1L+4 on 6arine 0ower 0lant $aboratory of 6arineengineering ;T% Department.

32 T7 I),/&()/, '. P&"#/#(+. 5iofuel oil.1. 0ertamina D7N il.2. %topwatch3. Tachometer4. >mperemeter8. /oltmeter.M. 7lectrical $oads in form of lamps circuit.


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CHAPTERI

DISCUSSION 9 RESULT OF THE LAB WORK

;/.; 0ractical 'esult

;n practical combustion engine work, the result we take written andarranged list by list. Data taken by two kind of fuel engine (bio solar, andsolar de). >nd this is the data we took.


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;/.;; -ormula #sed

To understand about the combustion:s engine work, formula must beeplained. 5y getting the formula, we can take the result. The point mustbe taken is


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a. 7ngine 0ower

0 Iv i

load factor

b. 7ngine Tor!ue

T IP

2 rps

c. 5rake 6ean 79ective 0ressure

5670 I

P

i l A z R p s

i I L.4 for 3strokel I length stroke> I cylinder areaK I total cylinder

d. %peci&c -uel il onsumption

%- I 6fP 5rake 0ower

e. Thermal 7?ciency

Qth I brake power P Rfuel

>fter putting the result gotten from the lab work to the formula, weput the result to the list. =ere the table list of those &ve points.

5io solar

7rpm

load(watt)

7ngine0owe tor!ue %- 5670

Thermal7?ciency

1@LL +LLL


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L


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(watt) 0ower 7?ciency

1@LL +LLL


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L 4@ 823 4+8 28M 1422LL 2LLL

13++.1@3++

combustion engine wpracticum report

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