TE lab manual

8/12/2019 TE lab manual

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VISHNU INSTITUTE OF TECHNOLOGY(Approved by A.I.C.T.E. & Affiliated to J.N.T.U.K.)

Vishnupur, BHIMAVARAM534 202

Tel: 08816 251333, Fax : 08816 250344

Thermal Engineering Lab Manual

III B.Tech. I Sem ME :: 201314

Department of Mechanical Engineering

OUR MISSION

Established by

SRI VISHNU EDUCATIONAL SOCIETY

153, Sita Nilayam, Dwarakapuri Colony, Punjagutta,

HYDERABAD 500 082. Ph. No. 23352916

TO PLAY A KEY ROLE IN THE DEVELOPMENT OF A

DISCIPLINED KNOWLEDGE SOCIETY


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VISION AND MISSION OF COLLEGE

Vision:

To ignite the minds of the students through academic excellence so as to bring about social

transformation and prosperity.

Mission:

To expand the frontiers of knowledge through Quality Education. To provide valued added Research and Development. To embody a spirit of excellence in Teaching, Creativity, Scholarship and Outreach. To provide a platform for synergy of Academy, Industry and Community. To inculcate high standards of Ethical and Professional Behavior.

VISION AND MISSION OF DEPARTMENT

Vision:

To foster prosperity through technological development by means of education,

innovation and collaborative research.

Mission:

To produce effective and responsible graduate and post-graduate engineers for globalrequirements by imparting quality education.

To improve the Departments infrastructure to facilitate research productivity andsuccess.

To integrate teaching and research for preservation and effective application ofknowledge and skills.

To strengthen and expand collaboration and partnerships with industry and otherorganizations.

To provide consultancy to the neighborhood and inculcate the spirit ofentrepreneurship.

To serve society through innovation and excellence in teaching and research.


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COURSE STRUCTURE

S. No. Subject T P Credits

1 Dynamics of Machinery 4 - 4

2 Metal Cutting & Machine Tools 4 - 4

3 Design of Machine MembersI 4 - 4

4 Finite Element Methods 4 - 4

5 Thermal Engineering II 4 - 4

6 Operations Research 4 - 4

7 Thermal Engineering Lab - 3 2

8 Machine Tools Lab - 3 2

9 IPR & Patent I 2 - -

Total 26 6 28


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INDEX

LIST OF EXPERIMENTS

S.No. Name of the Experiment Page No. Remarks

1Study Of Valve Timing Diagram on Four Stroke

Diesel Engine6

2Study Of Port Timing Diagram on Two Stroke

Petrol Engine9

3 Two stroke petrol engine test rig 12

4 Heat balance sheet of Two stroke petrol engine 18

5 Single Cylinder 4 Stroke Diesel Engine Test Rig 25

6Performance Test On Multi Cylinder 4 Stroke

Petrol Engine33

7 Morse Test On 4 Cylinder 4 Stroke Petrol Engine 40

8 Study of Boilers 44

9 Assembly& Disassembly of I.C.Engine 55


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Name of the student : Class :

Regd. No. : Branch :

Marks Assigned (Max. :15)

Date Name of the ExperimentExperimen

t(5)

Record

(5)

Atte.

(5)

Signatur

e of

faculty

Signature of Faculty Signature of HOD


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Exp No:

Date :

STUDY OF VALVE TIMING DIAGRAM ON FOUR STROKE DIESEL ENGINE

AIM:To find out the timing of inlet valve and exhaust valve opening and closing for the

given 4 stroke cycle engine and represent the result through a valve timing diagram

APPRATUS & EQUIPMENT:

1. Engine model2. Tape3. Chalk

THEORY:

It is a graphical representation of exact movement when the sequence of

operation in which the two values i.e. Inlet value and exhaust value opens and closed as

well as fining of the fuel. It is generally expressed in terms of angular position gunk shaft.The working of 4-stroke horizontal diesel engine consists of 4-stroke of the piston or

2 complete rotation of the gunk shaft. The strokes are

1. Suction Stroke2. Compression Stroke3. Power or Working Stroke4. Exhaust Stroke

SUCTION STROKE:

In this stroke inlet value opens before the piston reaches top dead centre on the

beginning of suction stroke takes places of angular position.


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COMPRESSION STROKE:

During this stroke the piston moves from bottom dead centre to top dead centre.

During this both inlet and outlet value remain closed.

POWER STROKE:

At the end of compression stroke the diesel oil is injected into engine cylinder with

the help of fuel value. The diesel is injected in the form of fine spray which gets ignited due

to high temperature of the compressed air. The Fuel value closes after the piston moves

from TDC. The burnt gases at high temperature and press pushes the piston down words

and some of heat energy is converted into mechanical work.

EXHAUST WORK:

During this stroke the piston moves from BDC to TDC and at the end of this stroke

the exhaust valve closes.

PROCEDURE:

The circumference of the brake drum is measured by means of the tape. The

flywheel is slowly rotated in the direction of rotation with the help of the decompression

level until the piston reaches the top most position. Mark T.D.C (top dead centre) on theflywheel. A pointer is made to coincide with the mark. The cover of the cylinder head is

removed to observe the opening and a closing of the valves from the movement of the

rocker arm. The flywheel is slowly rotated in the direction of rotation and the points at

which the opening and closure of both the valves are marked on the flywheel. A point

corresponding to the event of opening of valve of the injection pump (from the spill of the

fuel) is also marked.

A point directly below. T.D.C representing the B.D.C (bottom dead centre) is marked

on the flywheel. The circumferential distances of the various marks are now measured from

the T.D.C. They are converted into angles in degrees w.r.t the T.D.C & B.D.C.


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CALCULATIONS:

Perimeter of the flywheel = D = L = mmArc length between I.V.O and TDC = L1= mm

Arc length between I. V. C and TDC = L2= mm

Arc length between E.V.O and BDC = L3= mm

Arc length between E.V.C and TDC = L4= mm

Where D=Diameter of the flywheel (mm)

IVO = Inlet valve opens

IVC = Inlet valve closes

EVO = Exhaust valve opens

EVC = Exhaust valve closes

Crank angle per unit length.

= 360/L1= L1x =2= L2 x =

3= L3 x =4= L4x =

TABLE:

S.No Event Reference point Before/AfterTiming

mm Degrees

1 I.V.O

2 I.V.C

3 E.V.O

4 E.V.C

Result :-

From the angles calculated, the valve timing diagram is drawn.


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Exp No:

Date :

STUDY OF PORT TIMING DIAGRAM ON TWO STROKE PETROL ENGINE

AIM:

To find out the timing of inlet, transfer and exhaust port opening and closing for the

given 2-stroke cycle engine and represent the result through port timing diagram

APPRATUS & EQUIPMENT:

1. Engine model2. Tape3. Chalk

THEORY:

A two stroke engines performs only 2- stroke to complete one working cycle.

In this the suction Compression working and exhaust taken place during 2-strokes of the

piston. A two stroke engine has parts (holes) instead of values.

FIRST STROKE:

At the beginning of the first stroke the piston in the bottom rated centre. Both the

transverse part and the exhaust part are opened. The fresh air fuel mixture flows into theengine cylinder from the crank case. When the piston start to move up, first it covers the

transverse port and the exhaust post. After that the fuel is compressed as the piston moves

upwards in this stage the inlet post opens and fresh air fuel mixture enters into the crank

case.

SECOND STROKE:

In this stroke sharply before the piston reaches the top dead centre. The air fuel

mixture is ignited with the help of a spark plug. It suddenly increases an pressure and

temperature of products of combustion due to increase in pressure the piston is pushed

downward with a great force.

PROCEDURE:1. Identify the inlet and exhaust ports


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2. Throughout the experiment the rotation of the flywheel has to be In one directioneither clockwise or anti clockwise.

3. Mark the reference point for top dead center (TOC) and Bottom dead center (BOC)on the flywheel rotate the flywheel up to piston reaches the TDC coincide the piston

or one of the piston top or one of the piston ring edges with the exhaust port top

edge. Make a mark on the fly wheel with respect to fixed point (say TOC 1)

Rotate the fly wheel and when the piston moves towards BOC and when the piston

top or one of the piston ring edges again coincides with the same exhaust port edge,

make a mark on the fly wheel w.r.t to the fixed point (say TOC 2).

Measure the arc length from TOC 1 to TOC2 along the direction of rotation. Take half

of this arc length and mark a line from TOC I along the direction of rotation, indicate

the line as TOC. Take half of the circumference of the fly wheel and mark a line on

the fly wheel, indicate the line as BOC.

4. The opening and closing of the inlet port, exhaust port and transfer port are markedon the fly wheel When the piston just opens the inlet port completely, mark a point

on the fly wheel w.r.t to the fixed point indicate as IPO

When the piston just closes the inlet port completely, mark a point on the fly wheel

w.r.t to the fixed point indicates as IPC.

Similarly opening and closing of the exhaust port and transfer port are marked on

the fly wheel.

5. The port opening marks are measured from the nearest dead center and areconverted into angle units and are tabulated


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TABLE:

S.No Event Reference point Before/AfterTiming

mm Degrees

1 T.P.O

2 T.P.C

3 E.P.O

4 E.P.C

5 I.P.O

6 I.P.C

CALCULATIONS:

Circumference of the flywheel: D = mmCircumferential distance: 360

0

Transfer port opening position: 360 * L/DSimilarly other port opening & closing positions can be converted into angular units

and tabulated.

RESULT:

From the angles calculated the port timing diagram is drawn


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Exp No:

Date :

TWO STROKE PETROL ENGINE TEST RIGINTRODUCTION:

The prime movers using petroleum products as the source of energy are

being increasingly important in the modern world. It is needless to say that the countless

number of examples of these prime movers is being used right from household captive

power to hauling of aircrafts. The prime movers using petroleum products fall into two

categories, viz., Reciprocating & Rotary (Turbines) Engines.

The Reciprocating engines are commonly used ones, further divided into

Diesel, Petrol, Paraffin, Kerosene, Gas driven ones. While the rest are discussed elsewhere

in standard text books, the Petrol engine which is of our present concern fall into the

category of spark ignition prime mover which produces maximum power for minimum

weight as compared to any other reciprocating Prime movers.

The understanding of Speed Vs Load, Petrol Consumption Vs Load per UnitTime (Specific Fuel Consumption = SFC) and Efficiency is important from application point of

view to get the maximum benefit at minimum cost. The following paragraphs deal with the

engine and the test.

OBJECT:

To Conduct performance test on 2 - stroke Air Cooled Petrol Engine and to draw the

following graphs:

1. S.F.C. v/s B.P.

2. Mechanical Efficiency V/s B.P.3. Brake thermal efficiency, Volumetric Efficiency v/s B.P4. T.F.C Vs BP.

DESCRIPTION:

The Test Rig consists of Two-Stroke Petrol Engine (Air Cooled) to be tested for

performance is coupled to rope brake drum. The arrangement is made for the following

measurements of the set-up.

1) The Rate of Fuel Consumption is measured by using Volumetric Pipette.

2) Air Flow is measured by Manometer, connected to Air Box.

3) The different mechanical loading is achieved by loading the brake drum in

steps which is connected to the spring balances.

4) The engine speed is measured by electronic digital counter.

5) Temperature at air inlet, engine exhaust gas and exhaust gas calorimeter

water inlet, outlet are measured by electronic digital temperature indicator

with thermocouple.The whole instrumentation is mounted on a self-contained unit ready for operation.


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SPECIFICATIONS:

* TYPE : 2-Stroke Petrol Engine (Air

Cooled), Spark Ignition.

* MAKE : Bajaj.

* BORE & STROKE : 57mm x 57mm.

* COMPRESSION RATIO : 7.4: 1

* STARTING : By Kick Start.

* LOADING : By rope brake drum

* RADIAS OF BRAKE DRUM : 0.14 m

* DIA OF ORIFICE : 15 mm.

NOTE: At fourth top gear the engine, final output speed will be 970 rpm,

Because the gear transmission ratio is 5.36 in top gear.

OPERATION:1) Check the Petrol in the tank.

2) Keep gear / clutch lever (if provided) in neutral position.

3) Allow petrol, Start the engine by using kick start.

4) Keep the spring balances in zero readings, initially.

5). Apply load to the brake drum by rotating the wheels on the top of the spring

balances.

6) Using the acceleration stick keep the speed constant (Note + or - 5% of rated speed

is acceptable.)

7) Allow some time so that the speed stabilizes.

8) Now take down spring balance reading, temperature, petrol flow rate and air flow

rate.

9) Repeat the procedure (4) to (7) for different loads.

10) Tabulate the readings as shown in the enclosed sheet.

11) After the experiment is over, keep the petrol control valve at closed position, to

avoid riching of the engine for subsequent operation.


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2-STROKE SINGLE CYLINDER PETROL ENGINE TEST RIG (Mechanical Loading)

TABLE OF READINGS

Speed in

RPM of

ENGINE

Spring

balance

reading or

Load in Kg,

F1

Spring

balance

reading or

Load in Kg,

F2

Air

Consumptio

n in mm of

water read

On

manometer

Fuel Consumption Temperatures

Volume in

CC

Time in

Secs

T10

C

T20

C

T30

C

T40

C

T50

C

NOTE: TEMPERATURE POINTS,

T1 = Air Inlet Temperature

T2 = Water Inlet Temperature (to Exhaust Gas Calorimeter)

T3 = Water outlet Temperature (from Exhaust Gas calorimeter)

T4 = Exhaust Gas Inlet Temperature (to Exhaust Gas Calorimeter)

T5 = Exhaust Gas Outlet Temperature (from Exhaust Gas

Calorimeter)


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2-STROKE SINGLE CYLINDER PETROL ENGINE TEST RIG (Mechanical Loading)

TABLE OF CALCULATION

Load

in Kg

Engine

speedin

RPM

B.P.

In

KW

T.F.C.

In

Kg/hr.

S.F.C.

in

Kg/KW hr.

main

Kg/min.

mfin

Kg/min.

A/F

( air fuel

Ratio )

H.I.

in

KW

IP

In

KW

Brake

Thermal

Efficiency

Btherm

Mechanica

l Efficiency

mech

LIST OF FORMULAE

1. BRAKE POWER ( BP ):

2x 9.81x F x r

BPeng= --------------------------- KW

600000.7

whereN = RPM of Engine

r = Brake drum radius = 0.14m.

F = (F1-F2) in Kgf read from Spring Balances

Transmission efficiency=0.7

2. MASS OF FUEL CONSUMED PER MINUTE ( mf) :

Pipette Reading x P

x 60

mf

= ------------------------------------- Kg / min.

T x 1000Where,

P

= density of petrol

= 0.89 gm/ml

60 = Conversion from sec to min 1000 = Conversion from gm to Kg

3. TOTAL FUEL CONSUMPTION (TFC):

TFC = mfx 60 in Kg / hr.

Where,

mf = kg/min


16/60

60 = Conversion from min to hr.

4. SPECIFIC FUEL CONSUMPTION (SFC):

T.F.C.

S.F.C. = -------------- in Kg / KW - hr

B.P

5. HEAT INPUT ( HI ) :T.F.C.

HI = --------------- x CV in KW

60 x 60

Where,

TFC in Kg/hr.

CV = Calorific Value of petrol = 40,000 KJ/Kg (approx.)

6. BRAKE THERMAL EFFICIENCY ( Btherm) :

B.PBtherm = ------------- x 100

HI

7. AIR - FUEL RATIO: (A/F)

ma

AF = -----------

mf

Where, mf is in kg/minm

a=

V

ax

a in Kg / min

Va

= 60 x Cd

x A x (2 g ( hw

/ 1000) x [( w

/ a

) - 1] ) m3/Sec.

Cd

= 0.62,

d2

A = ------------- in m2 , d = 0.015m

4

hw

in mm of Water from manometer reading

g = 9.81 m/s2

a

= Density of Air

= 1.10 Kg/m3

w

= Density of water

= 1000 Kg/m3

8. INDICATED POWER ( IP ) :

IP = (BP + FP) KW

Where,

FP = (1/3) BP9. MECHANICAL EFFICIENCY m )


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BP

m = ---------- x 100 %

IP

GRAPHS:

1. TFC Vs BP2. Brake thermal efficiency Vs BP3. Mechanical efficiency Vs BP4. SFC Vs BP

Note: To find engine speed

N1 D2

--------- = -------

N2 D1

Where,

N1= Engine speed

N2= Speed in RPM indicator

D1= Diameter of the pulley on the engine sideD2= Diameter of the pulley on the Brake drum side

RESULT:


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Exp No:

Date :

HEAT BALANCE SHEET OF TWO STROKE PETROL ENGINE TEST RIG

INTRODUCTION:

The prime movers using petroleum products as the source of energy

are being increasingly important in the modern world. It is needless to say that thecountless number of examples of these prime movers are being used right from

household captive power to hauling of aircrafts. The prime movers using petroleum

products fall into two categories, viz., Reciprocating & Rotary ( Turbines ) Engines.

The Reciprocating engines are commonly used ones, further divided

into Diesel, Petrol, Paraffin, Kerosene, Gas driven ones. While the rest are

discussed elsewhere in standard text books, the Petrol engine which is of our

present concern fall into the category of spark ignition prime mover which produces

maximum power for minimum weight as compared to any other reciprocating

Prime movers.

The understanding of Speed Vs Load, Petrol Consumption Vs Load perUnit Time ( Specific Fuel Consumption = SFC ) and Efficiency is important from

application point of view to get the maximum benefit at minimum cost. The

following paragraphs deal with the engine and the test.

OBJECT:

To Conduct performance test on four - stroke Air Cooled Petrol Engine

and to draw the following graphs:

1. B.P. Vs S.F.C.

2. B.P. Vs mech,vol

3. B.P. Vs bth

4. T.F.C Vs BP.DESCRIPTION:

The Test Rig consists of Four-Stroke Petrol Engine ( Air Cooled ) to be

tested for performance is coupled to rope brake dynamometer. The arrangement is

made for the following measurements of the set-up.

1) The Rate of Fuel Consumption is measured by using Volumetric

Pipette.


3) The different loading are achieved by loading the rope brake

dynamometer in steps which is connected to spring balance.

4) The engine speed is measured by electronic digital counter.5) Temperature at air inlet and engine exhaust gas are measured by

electronic digital temperature indicator with thermocouple.

The whole instrumentation is mounted on a self-contained unit ready for operation.


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SPECIFICATIONS:

* ENGINE TYPE : 4-Stroke ,Single Cylinder

Petrol Engine, Spark Ignition.

* MAKE : Greaves.

* MAXIMUM POWER, P : 2.2 KW (Approx.)

* RATED SPEED, N : 3000 RPM.

* BORE , D : 70mm.* STROKE, L : 66.7mm.

* SWEAPT VOLUME, V : 256 Cm3

.

* COMPRESSION RATIO, CR : 4.67 : 1

* STARTING : By Rope.

* LOADING : Mechanical, by rope brake drum.

* COOLING : Air cooling for cylinder.

MEASUREMENTS:

* AIR INTAKE : By Volumetric Tank with

Orifice Dia d = 0.016mconnected to Manometer

(water), Cd

= 0.62

* ENGINE OUTPUT : By spring balances

* SPEED : By digital RPM indicator.

* FUEL FLOW : By Volumetric Pipette.

OPERATION:

1) Check the Petrol in the tank.

2) Allow petrol and start the engine by using Rope.3) Keep the spring balances in zero readings, initially.

4) Apply the Load to the engine by rotating the wheels provided at the top of

the spring balances.


6) Now take down spring balance readings, temperature, petrol flow rate and

air consumption.

7) Repeat the procedure ( 4 ) & ( 6 ) for different loads.


9) After the experiment is over, keep the petrol control valve closed.10) Release the loads and switch off the engine.


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HEAT BALANCE SHEET.

INPUT, KW %age OUTPUT, KW %age

a) HEAT INPUT TO

THE ENGINE, HI 100

b) HEAT EQUIVALENT TO

BRAKE POWER,

BP / HI

c) HEAT EQUIVALENT TOFRICTION POWER,

FP / HI

d) HEAT CARRIED AWAY BY

COOLING WATER, HW / HI

Will be zero

as engine is

air cooled

e) HEAT CARRIED AWAY BY

EXHAUST GAS, HG / HI

UNACCOUNTED HEAT LOSS,

HU / HITOTAL 100 TOTAL

EQUIPMENT : 4 - STROKE, SINGLE CYLINDER, PETROL ENGINE TEST RIG

( MECHANICAL LOADING & AIR COLLED )

TABLE OF READINGS

NOTE : TEMPERATURE POINTS,

T1 = AIR INLET TEMPERATURE

T2 = EXHAUST GAS INLET TO CLAORIMETER

EQUIPMENT : 4 - STROKE, SINGLE CYLINDER, PETROL ENGINE TEST RIG

( MECHANICAL LOADING & AIR COLLED )

TABLE CALCULATION

Speed in RPM

of ENGINE

Spring

balance

reading or

Load in Kg, F1

Spring balance

reading or

Load in Kg, F2

Air Consumption

in mm of water

read

On manometer

Fuel Consumption Temperatures

Volume in CC Time in Secs T10

C

T20

C


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Load

in Kg

B.P.

in

KW

T.F.C.

in

Kg/hr.

S.F.C.

in

Kg/K

W hr.

main

Kg/min.

mfin

Kg/min.

A/F

( air fuel

Ratio )

H.I.

in

KW

Swept

Volume,

Vs in

m3/min

Brake

Thermal

Efficiency

Btherm

Mech

Efficien

cy

mech

Volumetr

ic

Efficiency

vol

LIST OF FORMULAE

1. BRAKE POWER ( BP ) :

2 x x N x 9.81 x r x ( F1-F2)B.P(elec)= ----------------------- in KW

60,000

B.P(elec)

B.P(Eng)= -------------

tran

Where,

N = Speed of the engine.

F1, F2 = spring balance readings in Kg

r = radius of brake drum =0.125 m.

tran= transmission efficiency = 0.7


Pipette Reading x P

x 60

mf = ------------------------------------- Kg / min.

T x 1000

Where,

P

= density of petrol

= 0.72gm/ml

60 = Conversion from sec to min 1000 = Conversion from gm to Kg


TFC = mfx 60 in Kg / hr.


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Where, mf

=

kg/min, 60 = Conversion from min to hr.


T.F.C.

S.F.C. = -------------- in Kg / KW - hr

B.PENG


HI = ---------------x CV in KW

60 x 60

Where,

TFC in Kg/hr.

CV = Calorific Value of petrol = 40,000 KJ/Kg (approx.)

6. BRAKE THERMAL EFFICIENCY Btherm) :

B.PENG

Btherm = ------------- x 100

HI


ma

AF = -------m

f

Where, mf

is in kg/min

ma

=

60 x Cd

x A x Va

in Kg / min

i.e. Actual volume, Va

= (2 g ( hm

/ 1000) x [( w

/ a

) - 1] ) m3/Sec.

Cd

= 0.62,

d2

A = ------------- in m2 , d = 0.016m

4h

win mm of Water from manometer reading

g = 9.81 m/s2

a

= Density of Air

= 1.10 Kg/m3

w

= Density of water

= 1000 Kg/m3



23/60

IP = (BPENG+ FP) KW

Where,FP = (1/3) BP

9. MECHANICAL EFFICIENCY: (m )

BPENGm = ---------- x 100%

IP

10. VOLUMETRIC EFFICIENCY

V = (Vs / Vt) x 100

where Vs = Swept Volume , Vt = Theoretical Volume at STP.

a) Vt = Theoretical Volume

= ( d2

/4) x L x (N/2) m3

/minHere, D = bore dia in m, L = stroke length in m,

N = speed in rpm

b) Vs = Swept Volume at STP

= Va x (Ts/ Ta)

Here, Ta = Ambient Temperature, = T1o

K

Ts = Standard Temperature = 288o

K

11. HEAT BALANCE SHEET:

1. Heat Carried away by Exhaust Gas:

HEg

= mEg

cpg

TEg

KJ/S

Where, mEg

=(m

a+m

f)/60 in Kg/S

CPg

=

1.05 KJ/KgK

TEg = T2 -T1K

2. Heat Equivalent to Brake Power:

HBP = BPEng BPEng in KW3. Heat Input:

T.F.C.

HI = --------------x CV KW

60 x 60

4. Heat Lost due to FRICTION POWER :

HFP

= FP

5. Unaccounted Heat Lost:


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Hu

= (3) - [(1) + (2) + (4) ]

GRAPHS:

1. TFC Vs BP2. Brake thermal efficiency Vs BP3. Mechanical efficiency Vs BP4. Volumetric efficiency Vs BP5. SFC Vs BP

RESULT:


25/60

Exp No:

Date :

SINGLE CYLINDER 4 STROKE DIESEL ENGINE TEST RIG

INTRODUCTION:The prime movers using petroleum products as the source of energy

are being increasingly important in the modern world. It is needless to say that the

countless number of examples of these prime movers are being used right from

household captive power to hauling of aircrafts. The prime movers using petroleum

products fall into two categories, viz., Reciprocating & Rotary ( Turbines ) Engines.

The Reciprocating engines are commonly used ones, further divided

into Diesel, Petrol, Paraffin, Kerosene, Gas driven ones. While the rest are

discussed elsewhere in standard text books.

The understanding of Speed Vs Load, diesel Consumption Vs Load per

Unit Time ( Specific Fuel Consumption = SFC ) and Efficiency is important fromapplication point of view to get the maximum benefit at minimum cost. The

following paragraphs deal with the engine and the test.

OBJECTIVE:

To Conduct performance test on four - stroke Air Cooled Petrol Engine

and to draw the following graphs:

1. B.P. Vs S.F.C.

2. S.F.C. Vs bth

3. B.P. Vs bth

4. T.F.C Vs BP.

DESCRIPTION:

The Test Rig consists of Four-Stroke diesel Engine ( WATER Cooled ) to

be tested for performance is coupled to AC Generator. The arrangement is made for

the following measurements of the set-up.

1) The Rate of Fuel Consumption is measured by using Volumetric

Pipette.


3) The different electrical loading are achieved by loading the Electrical

generator in steps which is connected to the Air Heaters ( Resistance Load).

4) The engine speed & AC Alternator speed are measured by electronicdigital counter.

5) Temperature at air inlet and engine exhaust gas are measured by

electronic digital temperature indicator with thermocouple.

The whole instrumentation is mounted on a self-contained unit ready for operation.


26/60

SPECIFICATIONS:

ENGINE TYPE : 4-Stroke Single Cylinder Diesel Engine

* MAKE : Kirloskar.

* MAXIMUM POWER, P : 5HP

* RATED SPEED, N : 1500 RPM.

* BORE , D : 80mm.

* STROKE, L : 110mm.* STARTING : By DC motor

* LOADING : Electrical, Air Heater connected to

AC Generator

* COOLING : Water cooling .

MEASUREMENTS:

* AIR INTAKE : By Volumetric Tank with Orifice Dia d =

0.016m connected to

Manometer(water), Cd

= 0.62

ENGINE OUTPUT : By energy meter* SPEED : By digital RPM indicator.* FUEL FLOW : By Volumetric Pipette.

Engine output : By spring balance (Kgf) connected to swinging field dynamometer

Torque arm r = 0.8 m

Air intake : By volumetric tank with orifice dia, d = 16mm

Connected to U- tube, Manometer (water), Cd = 0.62.

OPERATION:

1) Check the diesel in the tank.

2) Allow diesel and start the engine by using Hand crank.

3) Keep the Loading Switches in OFF positions, initially.4) Apply the Load to the AC Generators by Switching - ON the loading switches.


6) Now take down Energy meter reading, temperature, petrol flow rate and air

consumption.

7) Repeat the procedure ( 4 ) & ( 5 ) for different loads.


9) After the experiment is over, keep the petrol control valve closed.


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HEAT BALANCE SHEET.

INPUT, KW %age OUTPUT, KW %age

a) HEATINPUT TO

THE ENGINE,

HI

100

b) HEAT EQUIVALENT TO BRAKE POWER,

BP / HI

c) HEAT EQUIVALENT TO FRICTION

POWER,FP / HI

d) HEAT CARRIED AWAY BY COOLING

WATER, HW / HI

e) HEAT CARRIED AWAY BY EXHAUST GAS,

HG / HI

UNACCOUNTED HEAT LOSS, HU / HI

TOTAL 100 TOTAL


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EQUIPMENT : 4 - STROKE, SINGLE CYLINDER, DISELE ENGINE TEST RIG

( ELECTRICAL LOADING & AIR COLLED )

TABLE OF READINGS

Water Flow Rate =

note : temperature points,

t1 = air inlet temperature t4 = water inlet temperature to calorimeter

t2 = engine head water inlet t5 = water outlet temperature from calorimetert3 = engine head water otlet t6 = exhaust gas inlet to calorimeter

t7 = exhaust gas otlet to calorimeter

Speedin RPM

of

ENGIN

E

Loading

switc

hes

AirConsumpti

on in mm

of water

read

On

manomet

er

FuelConsumption Temerature

Energymeter

reading

in No. of

revlns/ti

me

Voltmeter

reading

V in

volts

Ammeter

readin

g

I in

amps

Volum

e in CC

Time

in

Secs

T10

C

T20

C

T30

C

T40

C

T50

C


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EQUIPMENT : 4 - STROKE, SINGLE CYLINDER, DIESEL ENGINE TEST RIG

(ELECTRICAL LOADING & AIR COLLED )

TABLE CALCULATION

Load in

KW

B.P.

in

KW

T.F.C.

in

Kg/hr.

S.F.C.

in

Kg/KWhr.

main

Kg/min.

mfin

Kg/min.

A/F

( air fuel Ratio )

H.I. in KW Brake

Thermal

EfficiencyBtherm

Mechanical

Efficiency

mech

LIST OF FORMULAE

1. BRAKE POWER ( BP ) :

n x 60 x 60

B.P(elec)= ----------------------- KW

Emx t

B.P(elec)

B.P(Eng)= -------------

tran

Where,

n = No. of revln.of Energy meter

Em= Energy meter constant = 600 revln/KW-hr

t = time for n revln Of Energy meter in Sec.

tran = transmission efficiency = 0.7


Pipette Reading x P

x 60

mf

= ------------------------------------- Kg / min.

T x 1000

Where,


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30

P

= density of DIESEL

= 0.86gm/ml

60 = Conversion from sec to min

1000 = Conversion from gm to Kg


TFC = mf

x 60 in Kg / hr.

Where,

mf

=

kg/min



T.F.C.

S.F.C. = -------------- in Kg / KW - hr

B.PENG


HI = ---------------x CV in KW

60 x 60

Where,

TFC in Kg/hr.

CV = Calorific Value of Diesel = 40,000 KJ/Kg (approx.)


B.PENG

Btherm = ------------- x 100

HI


ma

AF = -------

mf


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Where, mf

is in kg/min

ma

=

60 x Cd

x A x Va

x a

in Kg / min

i.e. Va

= (2 g ( hm

/ 1000) x *( w

/ a

) - 1] ) m3/Sec.

Cd

= 0.62,

d2

A = ------------- in m2 , d = 0.016m

4

hw


g = 9.81 m/s2

a

= Density of Air

= 1.10 Kg/m3

w

= Density of water

= 1000 Kg/m3


IP = (BPENG+ FP) KW

Where,

FP = (1/3) BP


BPENGm = ---------- x 100%

IP

10. HEAT BALANCE SHEET

1. Heat Carried away by Exhaust Gas:

HEg

= mEg

cpg

TEg

KJ/S

Where, mEg

=(m

a+m

f)/60 in Kg/S

C

Pg

=

1.05 KJ/Kg

K

2. Heat Carried away by cooling Water ( Calorimeter ) :

Hwg

= mwg

CPw

Twg

KJ/S mwg

in Kg/S

CPw

=

4.18 KJ/KgK


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32

3. Heat Carried away by Engine Head cooling water:

Hwe

= mwe

CPw

Twe

KJ/S mwe

in Kg/S

CPw

=4.18 KJ/Kg

K

4. Heat Equivalent to Brake Power:

HBP

= BPEng

BPEng

in KW

5. Heat Input:

T.F.C.

HI = --------------x CV KW

60 x 60

6. Heat Lost due to FRICTION POWER :

HFP

= FP

7. Unaccounted Heat Lost:

Hu

= (5) - [(1) + (2) + (3) + (4) + (6)]

GRAPHS:

1. TFC Vs BP2. Brake thermal efficiency Vs BP3. Mechanical efficiency Vs BP4. SFC Vs BP

RESULT:


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33

Exp No:

Date :

PERFORMANCE TEST ON MULTI CYLINDER 4 STROKE PETROL ENGINE

Aim:- To conduct a performance test on 4cylinder 4stroke petrol engine and to study its

performance under various loads

Apparatus:-

A 4Cylinder 4stroke petrol engine with a eddy current dynamometer. A Tachometer of range (0-2000r.p.m)

Theory:-

SI engines works on Otto cycle or constant volume heat addition cycle. In this type ofengines self-ignition temperature is high and throttle controls the quantity of fuel-air mixture

introduced. Compression ratio ranges from 6-10. Due to light weight and also due to

homogeneous combustion, they are high speed engines. A Gaseous mixture of fuel-air is

introduced during the suction stroke. A carburetor and an ignition system are necessary.

Modern engines have gasoline injection.

Description:-

Multi cylinder 4 stroke water cooled petrol engine consists of:-

A Multi cylinder 4 stroke water cooled Hindustan brand petrol engine 10 HP at 1500 rpmcoupled to a eddy current dynamometer on a common base plate through a flexible

coupling. A single dry clutch arrangement is provided to declutch the engine from the

dynamometer for the purpose of setting the static balance of the dynamometer for no

load running of the engine. Necessary cooling water arrangement is provided for the

hydraulic dynamometer.

Fuel measuring arrangement consists of a fuel tank mounted on a sturdy stand, aburette, 3 way cock, connecting tubes. Air intake measuring consists of an air tank fitted

with an orifice plate, U tube manometer to measure the rate of flow of air sucked by the

engine. Two thermocouples are provided one to measure the air inlet temperature andother to measure exhaust temperature.

A digital temperature indicator with 6 channels is provided to measure the temperatureat various points in the test rig.

Cooling water arrangement consists of suitable piping system fitted to the engine withcontrol valve for regulating the flow, a water meter to measure the rate of flow of


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cooling water, 2 thermocouples to measure the inlet and outlet temperature of the

cooling water.


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Specifications:-

Make : Maruthi

Type : 4-stroke, petrol engine

( water cooled)

No.of cylinders : fourBore dia : 61mm

Stroke : 72mm

Cubic capacity : 1489c

Firing order : 1 3 4 2

Maximum hp : 10hp at 1500rpm

Compression ratio : 8.7:1

Orifice dia : 0.018m

Cdof orifice : 0.62

Battery negative : earth

Battery positive : solenoid switch

Procedure:-

Start the engine and allow the engine to run for sometime to reachsteady state conditions.

Close the fuel valve and find the time taken for 10ml of fuelconsumption, note down the speed at given load.

Apply load on the engine, note down the speed and time taken for10ml of fuel consumption at different loads and take a set of 5

readings.

Calculations:-

1) Brake power (BP) =

kw

Where

r = Torque arm length in m.

N = Speed in rpm.

f = Load in kg.



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Pipette Reading x P

x 60

mf

= ------------------------------------- Kg / min.

T x 1000

Where,

P = density of DIESEL= 0.86gm/ml

60 = Conversion from sec to min

1000 = Conversion from gm to Kg


TFC = mf

x 60 in Kg / hr.

Where,

mf = kg/min



T.F.C.

S.F.C. = -------------- in Kg / KW - hr

B.PENG


HI = ---------------x CV in KW

60 x 60

Where,

TFC in Kg/hr.

CV = Calorific Value of Diesel = 48,000 KJ/Kg (approx.)


B.PENGBtherm = ------------- x 100

HI



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ma

AF = -------

mf

Where, mf is in kg/minm

a=

60 x C

dx A x V

a x

a in Kg / min

i.e. Va

= (2 g ( hm

/ 1000) x [( w

/ a

) - 1] ) m3/Sec.

Cd

= 0.62,

d2

A = ------------- in m2 , d = 0.016m

4

Ha =

hw


g = 9.81 m/s2

a

= Density of Air

= 1.10 Kg/m3

w

= Density of water

= 1000 Kg/m3


IP = (BPENG+ FP) KW


BPENG

m = ---------- x 100% Vt

IP

10.VOLUMETRIC EFFICIENCY: (v)

vol =

where, Vs= swept volume, Vt= theoretical volume at STP


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Graph:-

TFC Vs BP SFC Vs BP Brake thermal efficiency Vs BP Mechanical efficiency Vs BP

Precautions:-

The engine should be stopped by cutting of the fuel supply. Keep the fuel line open. Keep the engine free from the load while starting or stopping.

Tabular form:-

Load

in Kg

Speed

in

RPM

B.P.

in

KW

T.F.C.

in

Kg/hr

.

S.F.C

.

in

Kg/K

W

hr.

main

Kg/mi

n.

mfin

Kg/mi

n.

A/F

( air

fuel

Ratio )

H.I.

in

KW

Brake

Thermal

Efficienc

y

Btherm

Mech

Efficie

ncy

mech

Volume

tric

Efficien

cy

vol

Result:-

The average Brake thermal efficiency of multi-cylinder 4stroke petrol engine at different

loads is


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39

QUIZ QUESTIONS

1. What are main differences between CI & SI engine.2. What are the compression ratios of a petrol engine?3. What is meant by compression ratio?4. Number crank revolutions in a 4 stroke petrol engine are.5. What is meant by fictional power?6. What is meant by brake power?7. What is meant by indicated power?8. SI engine works on which cycle?9. What are the different types of methods available for finding frictional power?10.In horizontal engines TDC & BDC are named as.


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40

Exp No:

Date :

MORSE TEST ON MULTI CYLINDER 4 STROKE PETROL ENGINE

Aim:- To conduct a Morse test on 4 cylinder 4 stroke petrol engine to calculate frictional power

and mechanical efficiency of the engine.

Apparatus & equipment:-

A 4 cylinder 4 stroke petrol engine with provision to cut off ignition to each cylinder

A tachometer of range (0-2000) rpm

Theory:-

The difference between the indicated and the brake power of an engine is known as

friction power. The friction loss is made up of the friction between the piston and cylinder

walls, piston rings and cylinder walls, and between the crankshaft and camshaft and their

bearings, as well as by the loss incurred by driving the essential accessories, such as the water

pump, ignition unit. Morse testis used to find the friction power.

The morse test consists of obtaining indicated power of the engine without any

elaborate equipment. The test consists of making inoperative, in turn, each cylinder of the

engine and noting the reduction in brake power developed. This test is applicable only to multi

cylinder engines

Description:-

Multi cylinder 4 stroke water cooled petrol engine consists of:-

1. A Multi cylinder 4 stroke water cooled Hindustan brand petrol engine 10 HP at 1500rpm coupled to a hydraulic dynamometer on a common base plate through a

flexible coupling. A single dry clutch arrangement is provided to declutch the engine

from the dynamometer for the purpose of setting the static balance of the

dynamometer for no load running of the engine. Necessary cooling water

arrangement is provided for the hydraulic dynamometer.

2. Fuel measuring arrangement consists of a fuel tank mounted on a sturdy stand, aburret, 3 way cock, connecting tubes. Air intake measuring consists of an air tank

fitted with an orifice plate, U tube manometer to measure the rate of flow of air

sucked by the engine. Two thermocouples are provided one to measure the air inlet

temperature and other to measure exhaust temperature.


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3. A digital temperature indicator with 6 channels is provided to measure thetemperature at various points in the test rig.

4. Cooling water arrangement consists of suitable piping system fitted to the enginewith control valve for regulating the flow, a water meter to measure the rate of flow

of cooling water, 2 thermocouples to measure the inlet and outlet temperature of

the cooling water.

Specifications:-

Make : Maruthi

Type : 4-stroke, petrol engine

( water cooled)

No.of cylinders : fourBore dia : 61mm

Stroke : 72mm

Cubic capacity : 1489c

Firing order : 1 3 4 2

Maximum hp : 10hp at 1500rpm

Compression ratio : 8.7:1

Orifice dia : 0.018m

Cdof orifice : 0.62

Battery negative : earth

Battery positive : solenoid switch

Procedure:-

1. Start the engine and allow the engine to run for some time to reach study statecondition.

2. Load the engine at half or or maximum load by turning the wheel of dynamometer inanti clockwise direction and by adjusting the throttle of the engine to run at 1500 rpm.

3. Run the engine with all the cylinders working and note down the power developed. Cutoff the first cylinder by the respective knife switch.

4. Adjust the speed of the engine to i8ts original valve by reducing the load from thedynamometer

5. Now note down the load when the first cylinder is cut off by operating the knife switch.


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6. Similarly cut off the cylinder no: 2 bring the engine to its rated speed by adjusting theload on the dynamomete4r and note down the corresponding load.

7. Repeat the above procedure to find out the load of the engine when the cylinder nos 3& 4 are cut off.

8. Release the load from the engine, declutch the engine and allow the engine to slowdown and stop the engine by cutting off the ignition switch.

Table:-

Sl

noCylinder condition

Load

(w)

kg

Speed

(N)

rpm

BP

kw

IP

kw

mechBP/IP

%

1When all the cylinders are working

2 When first cylinder is cut off

3 When second cylinder is cut off

4 When third cylinder is cut off

5 When fourth cylinder is cut off

Brake power when all the cylinders are working

BP =

Kw

R = Torque arm length = 0.358 m

N = speed of engine

W = load on the engine in kg

Brake power When first cylinder is cut off BP1 =

Kw

Brake power When second cylinder is cut off BP2 =

Kw

Brake power When third cylinder is cut off BP3 =

Kw


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43

Brake power When fourth cylinder is cut off BP4 =

Kw

Indicated power of first cylinder IP1 = BPBP1 kw

Indicated power of second cylinder IP2 = BPBP2 kw

Indicated power of third cylinder IP3 = BPBP3 kw

Indicated power of fourth cylinder IP4 = BPBP4 kw

Total Indicated power IP = IP1 +IP2+ IP3+ IP4

Frictional power FP = IPBP

Mechanical efficiency mech =

100

Result:- Frictional power of the engine is

QUIZ QUESTIONS

1. Morse test is applicable only to multi cylinder engine.2. The most accurate method of determining frictional power is measurement of brake

and indicated power

3. What are the different types methods available for finding frictional power?4. Why morse test is not suitable for single cylinder engine?5. What is meant by fictional power?6. What is meant by brake power?7. What is meant by indicated power?8. SI engine works on which cycle?9. Morse test is used to calculate?10.Swept volume is also called as?


44/60


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Essentials of good steam boilers:-

1. Steam production rate should be as per requirements.2. It should be absolutely reliable.3. It should be occupy minimum space.4. It should be light n weight.5. It should be capable of quick starting.6. It should be safe working.

Fire tube boilers:-

In fire tube boiler the furnace is generally located inside the boiler shell or drum, and the

heat fuel gases are led through the fire tubes which are surrounded by water.

Example:-

1. Simple vertical boiler.2. Locomotive boiler.3. Cochran boiler.4. Cornish boiler.5. Lancashire boiler.

Advantages:-

1. Simple design and more accessible for repairs.2.

Easy maintenance.

3. Low initial cost.4. Large water content provides safety in operation.5. Suitable for fluctuating loads.

Disadvantages:-

1. Rate of evaporation is low and suitable for only low capacities.2. Bigger in size.3. Lower efficiency.4. Suitable only low pressures.

Water tube boilers:-

In water tube boilers, water is made to pass through a large number of tubes over

which the hot gases flow. Most of modern boilers are built as water tube boilers.


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Example:-

1. Babcock and Wilcox boiler.2. Stirling boiler.3. Yarrow boiler.

Advantages:-

1. Suitable for high pressure and high capacity.2. Quickly starting.3. Smaller in size for a given output.4. Higher efficiency.5. Suitable for power plant.

Disadvantages:-

1. High initial cost.2. Complicated design and difficult to insert.3. Impure and dirty water is not suitable as feed water.4. Small water content causes the danger of explosion.

Comparison between fire tube and water tube boilers:-

Position of water and hot

gases.

Hot gases inside the tube and

water outside the tube.

Water inside the tubes and

hot gases outside the tubes.

Made of firing. Generally internally fired. Externally fired.

Rate of steam production. Lower. Higher.

Floor area. For given power it occupies

more floor area.

For given power it occupies

less floor area.

Construction. Difficult. Simple.

Transportation. Difficult. Simple.

Chance of explosion. Less. More.

Pressure range. Operate pressure range is 15

bar to 25 bar.

Operate pressure range is 165

bar to 200 bar.

Simple vertical boiler:-

It consists of cylindrical shell the greater portion of which is full of water and remaining is

the steam space. At the bottom of the fire box is grate on which fuel is burnt and the ash from

it falls in the ash pit.


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The fire box is provided with two cross tubes this increases the heating surface and the

circulation of water. The cross tubes are fitted inclined. This ensures efficient circulation of

water. At the ends of each cross tubes are provided hand holes to give access for cleaning these

tubes. The combustion gases after heating the water and thus converting it into steam escape

to the atmosphere through the chimney, man hole is provided to clean the interior of the boilerand exterior of the combustion chamber and chimney.

Advantages:-

1. Simple design and more accessible for repairs.2. Easy maintenance.3. Low initial cost.4. Suitable for fluctuating loads.

Disadvantages:-

1. Bigger in size.2. Lower efficiency.3. Suitable for only low pressures.

Cochran boilers:-

It is one of the best types of vertical multi tabular boiler, and has a number of horizontal

fire tubes.


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Dimensions, working pressure, capacity, heating surface and efficiency.

Shell diameter : 2.75meters.

Height : 5.79meters.

Working pressure : 6.5 bar (max p0= 15 bar).

Steam capacity : 3500kg/hr.Efficiency : 70 to75%

Cochran boilers consist of a cylinder shell with a dome shaped top where the space is

provided far steam. The frame furnace is one piece construction and is steam less. It crown has

a hemispherical shape and thus provides maximum volume of space. The fuel is burnt on the

grate and ash is collected and disposal of from ash pit. The fuel is burnt on grate. The gases of

combustion produced by burning the fuel enter the combustion chamber through the fire tube

and strike against fire brick lining which directs them to pass through number of horizontal

tubes being surrounded by water. After which the gases escapes to the atmosphere through

smoke box and chimney. Numbers of hand holes are provided around the outer shell for

cleaning purposes.

Advantages:-

1. Compact design and occupies less space.2. Cost of construction is low.3. Easy to install and transport.

Lancashire boiler:-


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The specifications of Lancashire boilers are

Diameter of shell : 2 to 3 meters.

Length of shell : 7 to 9 meters.

Maximum work pressure : 16 bar.

Steam capacity : 9000 kg/hr.

Efficiency : 50 to 70 %.

It consists of a cylindrical shell inside which two large tubes are placed. The shell is

constructed with several rings of cylindrical from and it is placed horizontally over a brick work

which forms several channels for the flow of hot gases. These two tubes are also constructed

with several rings of cylindrical form. They pass from one end of the shell of other end and are

covered with water. The furnace is paced at the front end of each tube and they are known as a

furnace tubes. The coal is introduced through the fire hole into grate. There is low brick were

fire bridge at the back of the gate to prevent the entry of burning coal and ashes into the

interior of furnace tubes.

The combustion products from the grate pass up to the back end of the furnace tubes and

then in downward direction. There after they move through the bottom channel up to the front

end of boiler where they are divided and pass up to the side flues and come to the chimney. To

control the flow of hot gases to chimney, dampers are provided as a result the flow of air to the

grate can be controlled.

Advantages:-

1. It is reliable.2. Has simplicity of design.3. Easy of operation.4. Less operating and maintenance cost.

Babcock and Wilcox boiler :-

The particular dimensions, capacity etc..

Diameter of drum = 1.22 to 1.83 m

Length = 6.096 to 9.1446 m


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50

Size of water tubes = 7.62 to 10.16 cm

Size of super heater tubes= 3.84 to 5.71 cm

Working pressure = 40 bar

Steaming capacity = 40000 kg/hr

Efficiency = 60 to 80 %

It consists a drum which contains water and steam. The drum is connected to headers

of by short tubes. The headers at right hand end of drum is called down take header and the

other at left handed is called uptake header. A series of inclined tubes are connected to these

headers.

A hand hole is provided in the header in front of each tube for cleaning the tubes. A

mud box is provided just below the down take header to collect the sediments and is removal

from time to time through blow off piece. Furnace is located below the uptake header baffles

are provided to deflect the hot gases so as to flow a longer paths. It is also provided with super

heater which is placed in the path of fuel gases.

Water from the drum enters the bottom header and flows through the tubes. The hot

gas flowing over the tubes heat and evaporate the water flowing through the tubes. Due to low

density, the mix of water and steam enters the drum through the uptake header. Steam is

separated at in the drum and collected above water level.

The steam from the drum is led into super heater which is placed in the path of hot

gases. Since the super heated is exposed to the hot gases.

The steam passing in it will be super heated steam is supplied to the prime mover

through steam stop valve.

LOCOMOTIVE BOILER

Locomotive boiler is a horizontal fire tube type mobile boiler. The main requirement of

this boiler is that it should produce steam at a very high rate. Therefore, this boiler requires a

large amount of heating surface and large grate area to burn coal at a rapid rate. Providingprovides the large heating surface area a large number of fire tubes and heat transfer rate is

increased by creating strong draught by means of steam jet.

A modern locomotive boiler is shown in Fig. 5.3. It consists of a shell or barrel of 1.5

meter in diameter and 4 meters in length. The cylindrical shell is fitted to a rectangular firebox

at one end and smoke box at the other end. The coal is manually fed on to the grates through

the fire door. A brick arch as shown in the figure deflects the hot gases, which are generated


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due to the burning of coal. The firebox is entirely surrounded by narrow water spaces except

for the fire hole and the ash-pit. The deflection of hot gases with the help of brick arch prevents

the flow of ash and coal particles with the gases and it also helps for heating the walls of the

firebox properly and uniformly. It also helps in igniting the volatile matter from coal. The walls

of the firebox work like an economizer. The ash-pit, which is situated below the firebox, is fittedwith dampers at its front and back end shown in the figure to control the flow of air to the

grate.

The hot gases from the firebox are passed through the fire tubes to the smoke box as

shown in the figure. The gases coming to smoke box are discharged to the atmosphere through

a short chimney with the help of a steam jet. All the fire tubes are f itted in the main shell. Some

of these tubes (24 in number)are of larger diameter (13 cm diameter) fitted at the upper part

of the shell and others (nearly 160 tubes) of 4.75 cm in diameter are fitted into the lower part

of the shell. The shell contains water surrounding all the tubes. The top tubes are made of

larger diameter to accommodate the super-heater tubes. Absorbing heat from the hot gases

flowing over the tubes superheats the steam passing through the super heater tubes. The

steam generated in the shell is collected over the water surface. A dome-shaped chamber,

known as steam dome, is fitted on the top of the shell. The dome helps to reduce the priming

as the distance of the steam entering into the dome and water level is increased. The steam in

the shell flows through a pipe mounted in the steam dome as shown in the figure into the

steam header which is divided into two parts. One part of the steam header is known as

saturated steam header and the other part is known as superheated steam header. The

saturated wet steam through the steam pipe enters into the saturated steam header and then

it is passed through the super-heater tubes as shown in the figure. The superheated steam

coming out of super-heater tubes is collected in the superheated header and then fed to the

steam engines. A stop valve serving also as a regulator for steam flow is provided inside a

cylindrical steam dome as shown in the figure. This is operated by the driver through a

regulator shaft passing from the front of the boiler.


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The supply of air to the grate is obtained by discharging the exhaust steam from the engine

through a blast pipe which is placed below the chimney. The air-flow caused by this method is

known asinduced draught. A large door at the front end of the smoke box is provided which can

be opened for cleaning the smoke box and fire tubes. The height of the chimney must be low to

facilitate the locomotive to pass through tunnels and bridges. Because of the short chimney,

artificial draught has to be created to drive out the hot gases. The draught is created with the

help of exhaust steam when locomotive is moving and with the help of live steam when the

locomotive is stationary. The motion of the locomotive helps not only to increase the draught,

but also to increase the heat transfer rate.

The pressure gauge and water level indicators are located m the driver's cabin at the

front of the fire box as shown in the figure. The spring loaded safety valve and fusible plug are

located as shown in the figure. Blow-off cock is provided at the bottom of the water wall to

remove the debris and mud.

The outstanding features of this boiler are listed below :

1. Large rate of steam generation per square metre of heating surface. To some extent this is

due

to the vibration caused by the motion.


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53

2. It is free from brickwork, special foundation and chimney. This reduces the cost of

installation.

3. It is very compact. The pressure of the steam is limited to about 20 bar. The details of

W.G.Type Locomotive Diameter and length of shell Ordinary tubes Large size tubes Pressure

and temperature of steam Grate area Heating surface area = 270 m2.The capacity of this boiler under normal load is 8500 kg/hr at 14.76 bar and 370C burning

158.5 kg of coal per hour/m2 of grate area.

Boiler manufactured at Chittaranjan are listed below : = 208.5 cm and 520.7 cm

= 116 and 57.15 mm in diameter = 38 and 114.3 mm in diameter = 14.76 bar and 370C

= 4.27112

Advantages:-

1. Generates stream at high pressure rate of steam generation is high.2. For given output, it occupies less space.3. Parts are accessible for cleaning, inspection are repaired.4. High efficiency of boiler is high.

Disadvantages:-

5. Requires pure feed water to avoid scale formation.6. Cost of boiler is high.7. Not suitable for mobile purpose.

Boiler mounting:-

1. Pressure gauge:- To indicate the pressure of steam generated.2. Water level indication:- To indicate water level in the boiler.3. Safety valve:- To allow the steam to escape if the steam pressure exceeds the

safe valve.

4. Fusible plug:- Safety device to protect boiler from overheating.5. Feed check valve:- Non return valve which allows the feed water to enter boiler.6. Blow off valve:- For removal of sediments.7. Stop valve:- To regulate the steam flowing out of boilers.8. Man hole:- Door to enter the boiler for inspection.

Accessories:-

1. Feed pump:- To force the feed water into boiler.2. Economizer:- To escape the temperature of feed water.3. Super heater:- To increase the temperature of steam above the saturation

point.


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4. Air pre heater:- To increase the temperature of air entering into thecombustion chamber.

5. Steam strap:- To drain away the condensed steam from pipe line.6. Steam separator:- To remove water particles from the steam flowing to engine.7.

Steam injector:- To supply the feed water to the boiler at high pressure.


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Exp No:

Date :

ASSEMBLY& DISASSEMBLY OF I.C.ENGINE

Cross-section of four-stroke cycle S1 engine showing engine components; (A) block, (B)

camshaft, (C) combustion chamber, (D) connecting rod, (E) crankcase, (F) crankshaft, (G)

cylinder, (H) exhaust manifold, (I) head, (J) intake manifold, (K) oil pan, (L) piston, (M) piston

rings, (N) push rod, (0) spark plug, (P) valve, (Q) water jacket.

ENGINE COMPONENTS

The following is a list of major components found in most reciprocating internal

combustion engines

Block Body of engine containing the cylinders, made of cast iron or aluminum. In many older

engines, the valves and valve ports were contained in the block. The block of water-cooled

engines includes a water jacket cast around thecylinders. On air-cooled engines, the exterior

surface of the block has coolingfins.


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Camshaft Rotating shaft used to push open valves at the proper time in the engine cycle, either

directly or through mechanical or hydraulic linkage (push rods, rocker arms, tappets). Most

modern automobile engines have one or more camshafts mounted in the engine head

(overhead cam). Most older engines

had camshafts in the crankcase. Camshafts are generally made of forged steel or cast iron andare driven off the crankshaft by means of a belt or chain (timing chain). To reduce weight, some

cams are made from a hollow shaft with the cam lobes press-fit on. In four-stroke cycle

engines, the camshaft rotates at

half engine speed.

Carburetor Venturi flow device which meters the proper amount of fuel into the air flow by

means of a pressure differential. For many decades it was the basic fuel metering system on all

automobile (and other) engines. It is still used on lowcost small engines like lawn mowers, but is

uncommon on new automobiles.

Catalytic converter Chamber mounted in exhaust flow containing catalytic material that

promotes reduction of emissions by chemical reaction.

Combustion chamber The end of the cylinder between the head and the piston face where

combustion occurs. The size of the combustion chamber continuously changes from a minimum

volume when the piston is at TDC to a maximum when the piston is at BDC. The term "cylinder"

is sometimes synonymous with "combustion chamber" (e.g., "the engine was firing on all

cylinders"). Some

engines have open combustion chambers which consist of one chamber for each cylinder.

Other engines have divided chambers which consist of dual chambers on each cylinder

connected by an orifice passage.

Connecting rod Rod connecting the piston with the rotating crankshaft, usually made of steel or

alloy forging in most engines but may be aluminum in some small engines.

Connecting rod bearing Bearing where connecting rod fastens to crankshaft.

Cooling fins Metal fins on the outside surfaces of cylinders and head of an aircooled engine.

These extended surfaces cool the cylinders by conduction and convection.

Crankcase Part of the engine block surrounding the rotating crankshaft. In many engines, the oil

pan makes up part of the crankcase housing.

Crankshaft Rotating shaft through which engine work output is supplied to external systems.

The crankshaft is connected to the engine block with the main bearings. It is rotated by the

reciprocating pistons through connecting rods connected to the crankshaft, offset from the axis

of rotation. This offset is sometimes called crank throw or crank radius. Most crankshafts are

made of forged steel, while some are made of cast iron.


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Cylinders The circular cylinders in the engine block in which the pistons reciprocate back and

forth. The walls of the cylinder have highly polished hard surfaces. Cylinders may be machined

directly in the engine block, or a hard metal (drawn steel) sleeve may be pressed into the softer

metal block. Sleeves may be dry sleeves, which do not contact the liquid in the water jacket, or

wet sleeves, which form part of the water jacket. In a few engines, the cylinder walls are given a

knurled surface to help hold a lubricant film on the walls. In some very rare cases, the crosssection of the cylinder is not round.

Exhaust manifold Piping system which carries exhaust gases away from the engine cylinders,

usually made of cast iron.

Exhaust system Flow system for removing exhaust gases from the cylinders, treating them, and

exhausting them to the surroundings. It consists of an exhaust manifold which carries the

exhaust gases away from the engine, a thermal or catalytic converter to reduce emissions, a

muffler to reduce engine noise, and a tailpipe to carry the exhaust gases away from the

passenger compartment.

Fan Most engines have an engine-driven fan to increase air flow through the radiator and

through the engine compartment, which increases waste heat removal from the engine. Fans

can be driven mechanically or electrically, and can run continuously or be used only when

needed.

Flywheel Rotating mass with a large moment of inertia connected to the crankshaft of the

engine. The purpose of the flywheel is to store energy and furnish a large angular momentum

that keeps the engine rotating between power strokes and smooths out engine operation. On

some aircraft engines the propeller serves as the flywheel, as does the rotating blade on many

lawn mowers.

Fuel injector A pressurized nozzle that sprays fuel into the incoming air on SI engines or into the

cylinder on CI engines. On SI engines, fuel injectors are located at the intake valve ports on

multipoint port injector systems and upstream at the intake manifold inlet on throttle body

injector systems. In a few SI engines, injectors spray directly into the combustion chamber.

Fuel pump Electrically or mechanically driven pump to supply fuel from the fuel tank (reservoir)

to the engine. Many modern automobiles have an electric fuel pump mounted submerged in

the fuel tank. Some small engines and early automobiles had no fuel pump, relying on gravity

feed.

Glow plug Small electrical resistance heater mounted inside the combustion chamber of many

CI engines, used to preheat the chamber enough so that combustion will occur when first

starting a cold engine. The glow plug is turned off after the engine is started.

Head The piece which closes the end of the cylinders, usually containing part of the clearance

volume of the combustion chamber. The head is usually cast iron or aluminum, and bolts to the


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engine block. In some less common engines, the head is one piece with the block. The head

contains the spark plugs in SI

engines and the fuel injectors in CI engines and some SI engines. Most modern engines have

the valves in the head, and many have the camshaft(s) positioned there also (overhead valves

and overhead cam).

Head gasket Gasket which serves as a sealant between the engine block and head where they

bolt together. They are usually made in sandwich construction of metal and composite

materials. Some engines use liquid head gaskets.

Intake manifold Piping system which delivers incoming air to the cylinders, usually made of cast

metal, plastic, or composite material. In most SI engines, fuel is added to the air in the intake

manifold system either by fuel injectors or with a carburetor. Some intake manifolds are heated

to enhance fuel evaporation. The individual pipe to a single cylinder is called a runner.

Main bearing The bearings connected to the engine block in which the crankshaft rotates. The

maximum number of main bearings would be equal to the number of pistons plus one, or one

between each set of pistons plus the two ends. On some less powerful engines, the number of

main bearings is less than this

maximum.

Oil pan Oil reservoir usually bolted to the bottom of the engine block, making up part of the

crankcase. Acts as the oil sump for most engines.

Oil pump Pump used to distribute oil from the oil sump to required lubrication points. The oil

pump can be electrically driven, but is most commonly mechanically driven by the engine.

Some small engines do not have an oil pump and are lubricated by splash distribution.

Oil sump Reservoir for the oil system of the engine, commonly part of the crankcase. Some

engines (aircraft) have a separate closed reservoir called a dry sump.

Piston The cylindrical-shaped mass that reciprocates back and forth in the cylinder, transmitting

the pressure forces in the combustion chamber to the rotating crankshaft. The top of the piston

is called the crown and the sides are called the skirt. The face on the crown makes up one wall

of the combustion chamber and may be a flat or highly contoured surface. Some pistons

contain an indented bowl in the crown, which makes up a large percent of the clearance

volume. Pistons are made of cast iron, steel, or aluminum. Iron and steel pistons can havesharper corners because of their higher strength. They also have lower thermal expansion,

which allows for tighter tolerances and less crevice volume. Aluminum pistons are lighter and

have less mass inertia. Sometimes synthetic or composite materials are used for the body of

the piston, with onlythe crown made of metal. Some pistons have a ceramic coating on the

face.


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Piston rings Metal rings that fit into circumferential grooves around the piston and form a

sliding surface against the cylinder walls. Near the top of the piston are usually two or more

compression rings made of highly polished hard chrome steel. The purpose of these is to form a

seal between the piston and cylinder

walls and to restrict the high-pressure gases in the combustion chamber from leaking past the

piston into the crankcase (blowby). Below the compression rings on the piston is at least one oilring, which assists in lubricating the cylinder walls and scrapes away excess oil to reduce oil

consumption.

Push rods Mechanical linkage between the camshaft and valves on overhead valve engines with

the camshaft in the crankcase. Many push rods have oil passages through their length as part of

a pressurized lubrication system.

Radiator Liquid-to-air heat exchanger of honeycomb construction used to remove heat from

the engine coolant after the engine has been cooled. The radiator is usually mounted in front of

the engine in the flow of air as the automobile moves forward. An engine-driven fan is often

used to increase air flow through

the radiator.

Spark plug Electrical device used to initiate combustion in an SI engine by creating a high-voltage

discharge across an electrode gap. Spark plugs are usually made of metal surrounded with ceramic

insulation. Some modern spark plugs have built-in pressure sensors which supply one of the inputs into

engine control.

Speed control-cruise control Automatic electric-mechanical control system that keeps the

automobile operating at a constant speed by controlling engine speed.

Starter Several methods are used to start IC engines. Most are started by use of an electric

motor (starter) geared to the engine flywheel. Energy is supplied from an electric battery. On

some very large engines, such as those found in large tractors and construction equipment,

electric starters have inadequate power, and small IC engines are used as starters for the large

IC engines. First the small engine is

started with the normal electric motor, and then the small engine engages gearing on the

flywheel of the large engine, turning it until the large engine starts. Early aircraft engines were

often started by hand spinning the propeller, which also served as the engine flywheel. Many

small engines on lawn mowersand similar equipment are hand started by pulling a rope wrapped around a pulley connected

to the crankshaft. Compressed air is used to start some large engines. Cylinder release valves

are opened, which keeps the pressure from increasing in the compression strokes. Compressed

air is then introduced into the cylinders, which rotates the engine in a free-wheeling mode.

When rotating inertia is established,the release valves are closed and the engine is fired.


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Supercharger Mechanical compressor powered off of the crankshaft, used to compress

incoming air of the engine.

Throttle Butterfly valve mounted at the upstream end of the intake system, used to control the

amount of air flow into an SI engine. Some small engines and stationary constant-speed engines

have no throttle.

Turbocharger Turbine-compressor used to compress incoming air into the engine. The turbine

is powered by the exhaust flow of the engine and thus takes very little useful work from the

engine.

Valves Used to allow flow into and out of the cylinder at the proper time in the cycle. Most

engines use poppet valves, which are spring loaded closed andpushed open by camshaft action.

Valves are mostly made of forged steel. Surfaces against which valves close are called valve

seats and are made of hardened steel or ceramic. Rotary valves and sleeve valves are

sometimes used, but are much less common. Many two-stroke cycle engines have ports (slots)

in the side of the cylinder walls instead of mechanical valves.

Water jacket System of liquid flow passages surrounding the cylinders, usually constructed as

part of the engine block and head. Engine coolant flows through the water jacket and keeps the

cylinder walls from overheating. The coolant is usually a water-ethylene glycol mixture.

Water pump Pump used to circulate engine coolant through the engine and radiator. It is

usually mechanically run off of the engine.

Wrist pin Pin fastening the connecting rod to the piston (also called the piston pin).

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