Basic Mechanical Engineering Lab Manual

8/19/2019 Basic Mechanical Engineering Lab Manual

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DEPARTMENT OF MECHANICAL

ENGINEERING

MH 2333 BASIC MECHANICAL

ENGINEERING LAB

LAB MANUAL

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INDEX

S.No NAME OF THE EXPERIMENT PAGE NO

1VALVE TIMING DIAGRAM AND PORT TIMING

DIAGRAM3

2PERFORMNCE TEST ON 4-STROKE DIESEL

ENGINE17

3HEAT BALANCE TEST ON 4-STROKE DIESEL

ENGINE 24

4MORSE TEST ON MULTICYLINDER PETROL

ENGINE 34

5RETARDATION TEST TO FIND FRICTIONAL

POWER OF A DIESEL ENGINE 41

6

DETERMINATION OF VISCOSITY

MEASUREMENT USING REDWOOD VISCOMETER 46

7 DETERMINATION OF FLASH AND FIRE POINT 51

8

PERFORMANCE TEST ON VAPOUR

COMPRESSION AIRCONDITION TEST RIG 56

9

VAPOUR COMPRESSION REFRIGERATION

SYSTEM 63

10PERFORMANCE STUDY IN A REFRIGERATOR

WITH CALORIMETER 69

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1. VALVE TIMING DIAGRAM AND PORT TIMING DIAGRAM

1.a. VALVE TIMING DIAGRAM

AIM

To draw the valve timing diagram for the given four stroke diesel engine.

APPARATUS RE!UIRED

1. Measuring tape

2. Scale

3. Feeler gauge

ENGINE SPECIFICATION

Make - kirloskar

Clinder - Single

!osition - "ertical

Cooling agent - #ater

Stroke - 11$ mm

%ore - &$ mm

%reak power - ' (!

Cu)ic capacit - ''$ cc

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DESCRIPTION

F"#$ S%$"&'( ") '*+,*'

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Va' T,/,*+ D,a+$a/ ") F"#$ S%$"&' E*+,*'

The four-stroke ccle1*T+C2*%+C A I*%a&'

B C"/0$'((,"*

C P"'$

D Ea#(%

5


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THEORY

The time valves in a ,-stroke engine ccle actuall open and close can )e measured ) angles. Theseangles can )e easil read using a valve-timing diagram.

To see how valve-timing works in a ,-stroke engine ccle lets show piston motion as a circle. /n thissimple ccle each stroke is shown as a semi-circle.

This intake valve opens at top dead center and closes at )ottom dead center. The )lue line shows that period and it matches the intake stroke.

The e0haust valve opens at )ottom dead center then closes at top dead center )efore the new air-fuelmi0ture enters the clinder.

/n practice the intake valve usuall opens earlier than top dead center and stas open a little past

)ottom dead center.

The e0haust valve opens a little )efore )ottom dead center and stas open a little past top dead center.

#hen the valves actuall open and close can )e measured ) angles. To make these angles easier toread lets use a spiral instead of a circle.

This intake valve opens 12 )efore the piston reaches top dead center.

nd it closes ,$ after )ottom dead center.

The e0haust valve opens , )efore )ottom dead center - and stas open - until 21 past top deadcenter. This gives e0haust gases more time to leave.

% the time the piston is at , )efore )ottom dead center on the power stroke com)ustion pressureshave dropped considera)l and little power is lost ) letting the e0haust gases have more time to e0it.

#hen an intake valve opens )efore top dead center and the e0haust valve opens )efore )ottom deadcenter it is called lead.

#hen an intake valve closes after )ottom dead center and the e0haust valve closes after top deadcenter it is called lag.

4n the e0haust stroke the intake and e0haust valve are open at the same time for a few degrees aroundtop dead center. This is called valve overlap. 4n this engine it is 33.

+ifferent engines use different timings. Manufacturer specifications contain the e0act information.

O0'*,*+ a* 5"(,*+ ") I*'% Va'

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The inlet valve is made to open 1$degree to 3$degree )efore the piston reaches the Top +ead Center 5T+C6 during Suction Stroke and is allowed to close onl after 3$degree to ,$degree after the pistonreaches and leaves the %+C in the )eginning of compression stroke.

Reason 7 The reason for doing this is to facilitate silent operation of the engine under high speeds. Theinlet valves are made to operate slowl to avoid noise and hence sufficient time should )e provided for the air-fuel mi0 to get into the clinder. Thus valves are made to open )efore the actual %+C.

Since the inlet valve is a small opening sufficient mi0ture doesnt enter the clinder in such short timeas the piston reaches %+C. Thus the inlet valve is kept open for some time period of time after %+C tofacilitate sufficient flowof charge into the clinder.

O0'*,*+ a* 5"(,*+ ") Ea#(% Va'

The e0haust valve is made to open 3$degree to 8$degree )efore the T+C in the e0haust stroke andallowed to close onl after &$ to 1$ in$ the )eginning of the suction stroke.

Reason 7 The gases inside the clinder posses a higher pressure even after the e0pansion stroke. Thishigher pressure ena)les it to move out of the clinder through the e0haust valve reducing the work thatneeds to )e done ) the engine piston in pushing out these gases. Thus the e0haust valve is made toopen )efore the piston reaches the %+C thus ena)ling the gases to escape outside on its own and the

remaining gases are pushed out ) the upward motion of the piston. #hen the piston reaches the T+Cif the e0haust valve is closed like in actual timing diagram a certain amount of e0haust gases will getcompressed and remain inside the clinder and will )e carried to the ne0t ccle also. To prevent thisthe e0haust valves are allowed to close onl a certain time after the piston reaches the T+C.

FORMULA

Crank ngle5θ6 * 5 38$ 9 C 6 : ;

#here

θ * Crank ngle

; * rc length of the fl wheel in mm

C * Circumference of the flwheel mm

OBSERVATION

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S N" E'*%P"(,%,"* A$5 L'*+%

//

A*+'

6D'+7

1 I*'% a' "0'*(6IVO7

2 I*'% a' 5"('(6IVC7

3 Ea#(% a' "0'*(6EVO7

4 Ea#(% a' 5"('(6EVC7

8 P#/0,*+ (%a$%(6PS7

9 P#/0,*+ '*(6PE7

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PROCEDURE

1. The /nlet and


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RESULT

The valve timing of the given four stroke engine is found out and the diagram is drawn.

+uration of suction stroke *

+uration of compression stroke *

+uration of e0pansion stroke *

+uration of e0haust stroke *

+uration of valve overlap *

1.:. PORT TIMING DIAGRAM

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AIM

To draw the port timing diagram for the given two stroke engine.

TOOLS RE!UIRED

1. Measuring tape2. Scale

ENGINE SPECIFICATION

Make - >a?dootClinder - Single

!osition - "ertical

Cooling agent - ir

Stroke - '& mm

%ore - 82 mm

Cu)ic capacit - 1' cc

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FIXING THE DEAD CENTRES

The flwheel is rotated and when the piston reaches an ar)itraril chosen location in the

clinder a mark is made on the flwheel against a fi0ed mark on the frame. The flwheel is rotated and

when the piston comes to the same mark in its downward stroke a mark is made on the flwheel againstthe fi0ed mark chosen. The midpoint of these two marks gives the T+C position of the piston and the

diametricall opposite position gives the %+C

IDENTIFICATION OF POSTS

The port which has more area and is nearer to the T+C is the e0haust port and the other one is

the inlet port. @ormall the e0port port is the )igger than the inlet port.

DIRECTION OF ROTATION

s the port opening and closing are smmetrical a)out the dead centre an ar)itrar direction of

rotation ma )e selected.

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PORT TIMING DIAGRAM

The Two-stroke ccle1*T+C2*%+C A,*%a&';(5a'*+,*+

BEa#(%

CC"/0$'((,"*

D E0a*(,"*60"'$7

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FORMULA

Crank ngle5θ6 * 5 38$ 9 C 6 : ;

#here

θ * Crank ngle

; * rc length of the fl wheel in mm

C * Circumference of flwheel

PROCEDURE

1. The flwheel is turned in an ar)itrar direction.

2. +uring the downward traverse position when it ?ust uncovers a port it is marked as the openingof the port on the flwheel.

3. The rotation is further continued until the piston covers the port during its upward travel.

,. mark is made on the flwheel against the fi0ed mark. This gives the closing of the port.

'. The same procedure is repeated for other ports also.

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OBSERVATION

SL NO EVENT POSITION

ARC

LENGTH

//

ANGLE

6DEG7

1 I*'% 0"$% "0'*6IPO7

2 I*'% 0"$% 5"('(6IPC7

3 Ea#(% 0"$% "0'*(6EPO7

4 Ea#(% 0"$% 5"('(6EPC7

8 T$a*()'$ 0"$% "0'*(6TPO7

9 T$a*()'$ 0"$% 5"('(6TPC7

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RESULT

Thus the port time for the given two stroke engine is found out and the port timing diagram isdrawn.

+uration of suction stroke *

+uration of compression stroke *

+uration of e0pansion stroke *

+uration of e0haust stroke * Scavenging period *

2. PERFORMNCE TEST ON 4-STROKE DIESEL ENGINE

A,/

To conduct the performance test on comet diesel engine and to draw the characteristic curves.

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A00a$a%#( $'


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Dead Centre 5T+C6 when the piston is farthest awa from the a0is of the crankshaft. ccle refers to

the full travel of the piston from Top +ead Centre 5T+C6 to %ottom +ead Centre 5%+C6.

1. /@T< strokeD on the intake or induction stroke of the piston the piston descends from the top of

the clinder to the )ottom of the clinder reducing the pressure inside the clinder. mi0ture of fuel

and air or ?ust air in a diesel engine is forced ) atmospheric 5or greater6 pressure into the clinder

through the intake port. The intake valve5s6 then close. The volume of air9fuel mi0ture that is drawn

into the clinder relative to the volume of the clinder is called the volumetric efficienc of the

engine.

2. C4M!>


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,.


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'. Mechanical efficienc 5m6

m * %! 9 /! : 1$$

#here/! * %! K F!/! - /ndicated power in kw%! - %reak power in #F! - Frictional power in kw 5 from %! "s TFC Hraph6

PROCEDURE

1. The ma0imum load for which the engine can )e loaded is found.

2. The fuel lu)ricating oil and cooling levels are checked.

3. +ecompression level is engaged and the engine is cranked. s soon as flwheel rotates withConsidera)le speed decompression lever is disengaged to start the engine.

,. The load can )e altered ) the field rheostat and the voltage is maintained at 22$".

'. The time taken for ,$cc fuel consumption is noted down ) using stopwatch.

8. The reading is noted down for different ammeter reading.

. Esing these values %! TFC SFCm and ) are found.

&. These various parameters are plotted on a graph with respect to the change in )reak power.

GRAPH

%reak power "S Total fuel consumption

%reak power "S Specific fuel consumption

%reak power "S %reak thermal efficienc

%reak power "S Mechanical efficienc

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TABULATION

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S; @4

;4+ %reak!ower #

Time for ,$cc of fuelconsumptionLt Sec.

Total fuelconsumptionT.F.C H9(r

Specific fuelconsumptionS.F.CH9#-(r

%reakThermalefficienc)th

Mechanicalefficiencmech

#H

SH

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RESULT

The performance test on the comet engine was conducted and the characteristic curves were

drawn

3. HEAT BALANCE TEST ON 4-STROKE DIESEL ENGINE

A,/

To conduct the heat )alance test on comet diesel engine and to draw the heat )alance sheet.

A00a$a%#( $'


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%reak power - 1$ (!

Speed - 1'$$ rpm

DIAGRAM

Four-Stroke Ccle +iesel


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Figure 1-- The components of a diesel engine

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Figure 1-.-+iesel and gasoline engines compression strokes.

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Figure 1-&.-+iesel and gasoline engines intake strokes.

Figure 1-.-+iesel and gasoline engines regulation of power.

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The air and fuel then mi0 in the com)ustion cham)er 5fig. 1-&6. The engine speed and the power output

of a diesel engine are controlled ) the =uantit of fuel admitted to the com)ustion cham)er. The

amount of air is constant. 4n the gasoline engine the speed and power output is regulated ) limiting

the air and fuel mi0ture entering the engine 5fig. 1-6. diesel engine is much more efficient than a

gasoline engine such as the diesel engine does not re=uire an ignition sstem due to the heat generated

) the higher compression the diesel engine has a )etter fuel econom due to the complete )urning of

the fuel and the diesel engine develops greater tor=ue due to the power developed from the high-

compression ratio.

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and as the piston reaches )ottom dead center the intake valve closes 5fig. 1-1$ view 6.

Figure 1-1$.-Four-stroke ccle diesel engine.

F"$/#a' #('

1. (eat supplied 5Ns6

Ns * mf : C"

mf * 5 :9 t6 : 5 s91$$$6 g9sec

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#here

: - Fuel consumption in cc *,$cct - time for ,$cc of fuel consumption in secs - specific gravit of diesel5$.&36

C" - Calorific value in kJ9g 5,3$$$6

2. (eat convert to )reak power 5Na6

Na *%! * " : / 9 51$$$ : g6

#here

%! - %reak power in #" - volt meter reading in volts/ - mmeter reading in mps

Gg - Henerator efficienc 5&$I63. (eat carried awa ) cooling waterD

Nw * mw Cpw 5TwoOTwi6

#here mount of water collected5,g6mw --- Flow rate of water in kg9sec * Time taken 5t6

Cpw --- specific heat capacit of water in J9gP

Two 7 Cooling water outlet temp in C̊

Twi 7 Cooling water inlet temp in PC

,. (eat carried awa ) e0haust gasD

Ng * mg Cpg 5TgoOTgi6

mg * ma K mf ma * Cd : Q 2 : g:hw: Ra:Rw kg9sec#here Cd - Co-efficent of discharge * $.8, - rea of !ipe * 9, 5$.$,62 * $.$$13 m2 H - cc. +ue to gravit * .&1m9sec2 (w - h1 7 h2 in m. Ra - +ensit of air * 1.182 kg9m3

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Rw - +ensit of water * 1$$$ kg9m3 Tgo -


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PROCEDURE-

1. The ma0 load to which the engine can )e loaded is found.

2. The fuel lu)ricating oil cooling water levels are checked.

3. The engine is cranked and started ) engaging decompression lever.

,. epeat the


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GRAPH>-

;oad "s (eat losses.

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RESULT-

Thus the heat )alance test on comet engine ) ir flow method and the heat )alance sheet are

drawn.

4. MORSE TEST ON MULTICYLINDER PETROL ENGINE

AIM

To conduct the morse test on , stroke , clinder petrol engine for determining frictional power.

APPARATUS RE!UIRED

Fiat engine setup

Tacho meter

stop watch

ENGINE SPECIFICATION-

Make - Fiat

Clinder - Four

!osition - "ertical

Cooling gent - #ater

Stroke - ' mm

%ore - 8& mm

%reak !ower - ,2 (!

Speed - ,'$$ >!M

WORKING PRINCIPLE.

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/n four stroke engine the work is o)tained onl during one stroke out of these for a single clinder

engine or for ever clinder individuall for multi clinder engine./f ou have an automo)ile vehicle

or machinethen ou )etter know the a)ove terms.%ut ever ou knowwhich are these strokes and how it

performX /nterested to go deep in topicX >ead )elow description.

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$16 Suction Stroke.

This is first stroke of our engine. +uring this stroke the piston is moved downward from Top

+ead Centre ) means of crankshaft which is rotate ) electric motor. This movement increases the

siYe of com)ustion space there) reducing the pressure inside the clinder as the result the higher

pressure of the outside atmosphere forces the air into com)ustion space through suction valve. The

e0haust valve remain closed in this stroke. car)urettor is put in the passage of incoming air which

supplies a controlled =uantit of fuel to this air. This air-fuel mi0ture thus comes in engine clinder.

$26 Compression Stroke.

This is second stroke of our engine. The air-fuel mi0ture is compressed during this upward

stroke. The compression forces the fuel into closer com)ination with air. (eat is produced due tocompression aids the com)ustion of fuel. Just a little )efore the end of compression stroke the mi0ture

is ignited ) a spark produced ) spark plug. +uring this stroke suction and e0haust valve remain

closed.

$36 !ower Stroke.

This is third stroke of our engine. Vou ma call it as


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work done carried out ) engine./ hopethis information will )etter help ou to understand the working

of our four stroke engine.

DIAGRAM

T' 4 S%$"&' P'%$" E*+,*'

.

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FORMULA USED-

1. Tor=ue

T * > 0 S 0 g @m

#here

> - >adius of +namometer $.32 m S - ;oad kg H - cceleration due to gravit m9s2

2. %rake !owerD 5%!6

%! * 2@T --------# 8$$$$#here

@ -


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1. The engine is started ) using ignition switch W starter motor.

2. t first all four clinders are running W speed is kept at 12$$ rpm ) using throttle valve

3. "alve of hdraulic load is measured

,. Then the first clinder is cut off W speed is maintained ) decreasing the load

'. This is done ) closing the valve for the hdraulic load dnamometer

8. The valve of load is noted down.

. Similarl second third W fourth clinders are cut off W procedure is repeated.

TABULATION-

C4@+/T/4@ ;4+H

S!


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RESULT

Thus the Morse test was conducted on four clinder petrol engine W frictional power is

determined.

8. RETARDATION TEST TO FIND FRICTIONAL POWER OF A DIESEL ENGINE

AIM

To conduct a retardation test on ruston diesel engine and to determine the frictional power.

APPARATUS RE!UIREDD

>uston engine setup

Tachometer

#eights

ENGINE SPECIFICATION-

Make - >ustonClinder - Single

!osition - (oriYontal

Cooling gent - #ater

Stroke - 28 mm

%ore - 1,3 mm

Speed - '$$ rpm

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DIAGRAM

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FORMULA USED-

1. %rake tor=ue 5T)6

5T)6 * load 0 radius

2. Frictional tor=ue 5Tf6Tf * T) t3

----------@m T2-t3

#here

T2t3 - from graph

3. Frictional !ower 5F!6

F! * 2@Tf --------- # 8$$$$

PROCEDURE

1. Start the engine o)serving all precautions without load.

2. d?ust the speed to rated valve

3. Cut off fuel suppl W note time taken for ever 1$$ mm retardation

,. >epeat the procedure for 2'I load

'. Calculate frictional tor=ue W frictional power.

TABULATION

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S; @4 +>4! /@S!


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RESULT

Thus retardation test on a ruston diesel engine was conducted W frictional power was

determined.

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8. DETERMINATION OF VISCOSITY MEASUREMENT USING REDWOODVISCOMETER

A,/

To determine the kinematic viscosit of the given oil at varioustemperatures ) means of >edwood viscometer.

A00a$a%#(

>edwood viscometer

Thermometer

'$cc receiving flask Stop watch

T'"$=

The viscosit is a measure of the internal resistance to the flow of fluids. /t is measured in poise.

The kinematic viscosit of a li=uid is the ratio of the a)solute viscosit to its densit at the given

temperature and the unit is mU9S. The time re=uired for the given =uantit of oil to flow through an

orifice is a function of its kinematic viscosit. The time re=uired in seconds for '$cc of oil to gravitate

through the orifice or ?et or redwood viscometer at given temp is e0pressed as its viscosit in redwood

seconds at that temperature.

D'(5$,0%,"*

The redwood viscometer comprises of vertical clindrical cup with an a0ial ?et at the )ottom.

The ?et can )e closed ) a )all valve 9 stopper. There is a marker near the top of the cup to control thelevel to which the test oil should )e filled in the cup. There is a thermometer which measures the oil

temperature. The cup is surrounded ) a water ?acket. n electric heater coil can heat the wate>.

regulator 9auto transformer can control the input energ to the coil. stirrer in the ?acket maintains

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uniform temperature of the )ath. The ?acket is integral with the housing . There are leveling screws at

the )ase of the housing to ensure that the ?et is e0actl vertical.

TABULATION

S; @4 T


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DIAGRAM

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P$"5'#$'

1. The oil cup of the viscometer is cleaned well and the given oil is filled into the cup.

2. The '$cc collecting flask is placed in position )elow the orifice.

3. The water is heated to maintain the oil at different temperatures using electric heater.

,. The temp at which )oth oil and water are e=ual is noted.

'. The )all valve is opened and the time taken to drain '$cc of oil is noted.

8. The same procedure is repeated to find the viscosit of the oil at different temperatures and theresults are ta)ulated.

G$a0

Temperature "s inematic viscosit

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RESULT

The viscosit of the given oil was found at different temperatures and a graph was drawn )etweentemperature W kinematic viscosit.

. DETERMINATION OF FLASH AND FIRE POINT

A,/

To determine the flash and fire point of the given fuel sample.

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A00a$a%#( $'


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The )les apparatus

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P$"5'#$'

1. Clean and dr all parts of the cup and its accessories thoroughl )efore the test is started.

2. Fill the cup with the sample of oil to the tested upto the level indicated ) the filling mark.

3. /nsert the thermometer into the sample to note the temperature.

,. ;ight and ad?ust the test flame.

'. Connect the heater to the main through the regulator

8. d?ust the rate of heating as 2O' PC per minute.

. The temperature of the oil reaches the temperatures of a)out 2' PC )elow the e0pected

flash point temperature appl the test flame at regular intervals sa ever 2 PC temperature

rise.

8. #hen the application of the test flame results to district momentr flash in the cup over the

oil surface note down the temperatures. This is the Flash !oint of the given oil.

. Continue appling the test flame over the oil surface. #hen there occurs a continuous

flame on the oil surface which is alive for at least ' seconds note down the temperature.

This is the Fire point of the given oil.

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TABULATION

Sa/0' 1

Flash point PC Fire point PC

Sa/0' 2

Flash point PC Fire point PC

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RESULT

The flash and fire point of the given sample was determined using )les apparatus.

8. PERFORMANCE TEST ON VAPOUR COMPRESSION

AIRCONDITION TEST RIG

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AIM

To conduct a performance test and to find out the actual and theoretical C4! of a given ir-conditioning

unit.

THEORY

tmospheric air alwas contains water vapour. The content of water vapour in air also plas an

important role in comfort air-conditioning. The science which deals with the stud of the )ehavior of air and

water vapour mi0ture is known as pschrometr. The properties of water vapour and air mi0ture are known as

pschometric properties. The few pschometric properties are discussed.

617 D$= a,$

The mi0ture of nitrogen and o0gen neglecting the water vapour and other gases is known as

dr air. The volumetric composition of dr air is I of nitrogen and 23I o0gen.627 M",(% a,$

/t is a mi0ture of dr air and water vapour. The ma0imum =uantit of water vapour that can )e

present in air depends upon the temperature of the air.637 M",(%#$'

The water vapour present in the air is known as moisture and its =uantit in air is an important

factor in all air-conditioning sstems.647 D$=-:#: %'/0'$a%#$'

The temperature of air measured ) ordinar thermometer is known as +r )ul) temperature687 W'%-:#: %'/0'$a%#$'

The temperature of air measured ) thermometer when its )ul) is covered with wet cloth and is

e0posed to a current of air is known as wet-)ul) temperature. The difference )etween the dr-)ul) and

wet )ul) temperature is known as wet-)ul) depression. The wet )ul) depression will )e Yero when the

air )ecomes saturated.697 D' 0",*% %'/0'$a%#$'

/t is defined as the temperature at which the moisture present in the air )egins to

condense when the air is cooled.6?7 S0'5,),5 #/,,%=

/t is the mass of water vapour present with one kg of dr air.6@7 R'a%,' #/,,%=

/t is e=ual the ratio of actual volume of water vapour in a given volume to the mass of water vapour if

the same volume of air is saturated at same temperature.

67 D'+$'' ") (a%#$a%,"*

This is defined as the ratio of mass water vapour in unit mass of dr air to mass of water vapour in unit mass

of dr air when air is saturated at same temperature.56


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I*%$"#5%,"*

ir Conditioning for human comfort or industrial process re=uires certain processes to )e carried out on air to

var the pschometric properties of air to re=uirements. These processes ma involve the mi0ing of air streams

heating of air cooling of the air humidifing air and dehumidifing air and com)ination of the process. ll such

processes are studies with the given air-condition test rig.

DESCRIPTION

The vapour compression air condition test rig is designed for e0clusive stud of refrigerant properties

while air conditioning an environment of correct temperature humidit and air movement. The test rig consists

of a closed tpe compressor energ meter to measure electrical input to the compressor and heater pressure

gauges and thermocouple sensor fitted at respective locations digital temperature indicator air cooled

condenser an e0pansion valve etc. ir-cooled tpe evaporator. The air is passed ) a 0ial flow fan through the

duct. The e0panded refrigerant passes through the coil fi0ed in the duct. The passing air comes in contact withthe coil.

Multiple air heater is provided in the duct for dehumidification. #et and dr )ul) temperatures are

measured at the inlet and outlet section of the duct. The flow of air is measured using an nemometer.

The whole unit with panel and air circulation sstem mounted on a trolle with caster wheels. The

pipelines are suita)l colour to indicate different states of the gas.

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PROCEDURE

1. Switch on the main power suppl to test-rig.2. Switch on the condenser fan compressor and )lower.3. llow the sstem to run for a)out 3 minutes to attain stead condition.

,. @ote down the atmospheric temperature.'. llow the sstem to run for a)out 1$ minutes.8. @ote down the pressures p1 p2 p3 W p, and corresponding temperature T1 T2 T3 WT,.. @ote down the air velocit using anemometer.&. @ote down the dr )ul) and wet )ul) temperatures of air at inlet and outlet of evaporator.. @ote down the time taken for 1$ revolutions of energ meter disk.1$. Switch off the main power suppl.

MODEL CALCULATION


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#here < * efrigeration effect 9 !ower inputTheoretical method

From ! 7 h Chart 5 >22 6

(1 *(2 *(3 *(, *

C4! * 5(, 7 (3 6 9 5(1 7 (26

This is calculated using refrigerant ta)le or refrigerant chart using pressure and temperature.

;ocate the cardinal points find out corresponding enthalpies from the p-h chart.

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TABULATION A,$ C"*,%,"*,*+ T'(% R,+

S/.

@o.

Temperature in c !ressures in )ar /nlet >eading 4utlet

>eadingTime for 1$ rev.energ

meter of compress

or

Time for 1$ rev.energ

meter of heater

nemometer

>eadingT1 T2 T3 T, !1 !2 !3 !, #%T +%T #%T +%T

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RESULT

The performance tests on vapour compression air compression test have )een carried out and the actual and theoretical C4! were fond out.

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. VAPOUR COMPRESSION REFRIGERATION SYSTEM

/MD To conduct a Test on vapour compression refrigerator test rig and to calculate thetheoretical C4! of Carnot and the efficienc of ccle.

S!efrigerant * Tetra Flora 13,a^

Compressor motor * 193 (!

>ated voltage * 22$ " Single phase.

Current of 22$ " * 3 .1

F4>ME;D

1. Theoritical C4! * h2 - h3

h1- h2

2. ctual C4! * >efrigeration effect

efrigeration effect * ms 5Ti 7 Tf 6

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#here

M - mass of water in kg 5& g6

S - specific heat of water * ,.&1 kJ9kg°C

Ti - /nitial temperature of water

Tf - Final temperature of water

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VAPOUR COMPRESSION REFRIGERATION TEST RIG

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PROCEDURE

1. The re=uired valves are opened and rest are closed.

2. known mass of water is taken in chiller unit

3. /nitial temperature of water is noted

,. Therometers are put inside socket.

'. Enit is started and allowed to run for sterilit.

8. Final temperature at various places noted

. Tince for 0 revolutions of energ meter

&. >eadings are ta)ulated.

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Va0"#$ C"/0$'((,"* ,% R')$,+'$a%,"* S=(%'/

S.@o

Time

periodLTminutes

>efrigerated Temp>eading 5°C6

Time for

energ meter disc

Tempin

chiller

T'

5T f 6

°C

!ressure a)solute 5)ar6 TheoreticalC4! ctualC4!

T1 T2 T3 T,Compressor

51$ rev6!1 !2 !3 !,

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>


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A,/

To stud the performance of refrigeration with calorimeter sstem

C"/0"*'*%(

Re!"#e!a$"on s%s$e&'

>efrigerant


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Sandwich Calorimeter

A,a:a%,5 5a"$,/'%'$-

n adia)atic calorimeter is a calorimeter used to e0amine a runawa reaction. Since the

calorimeter runs in an adia)atic environment an heat generated ) the material sample undertest causes the sample to increase in temperature. Thus fuelling the reaction.

@o adia)atic calorimeter is full adia)atic- some heat will )e lost ) the sample holder. mathematical correction factor known as the phi-factor can )e ad?ust the calorimeter result toaccount for these heat losses. The phi-factor is the ratio of the thermal mass of the sample andsample holder to the thermal mass of the sample alone.

R'a5%,"* 5a"$,/'%'$-

>eaction calorimeter can )e used to determine ma0imum heat release rate for chemical processengineering and for tracking the glo)al kinetics of rection. There are four main method formeasuring the heat in reaction calorimeter.

H'a% )" 5a"$,/'%'$

The cooling9heating ?acket controls either the temperature of the ?acket. (eat is measured )monitoring the temperature difference )etween heat transfer fluid and the process fluid.

H'a% :aa*5' 5a"$,/'%'$

The cooling9heating ?acket controls the temperature of the process. (eat is measured )monitoring the heat gained or lost ) the heat transfer fluid.

P"'$ 5"/0'*(a%,"*

!ower compensation uses a heater placed within the vessel to maintain a constant temperature.The energ supplied to this heater can )e varied as reaction re=uire and the calorimeter signal is

purel derived from this electrical power.

C"*(%a*% )#

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Constant flu0 calorimeter 5or C4F;E: as it is often termed6 is derived from heat )alancecalorimetr and uses specialiYed control mechanisms to maintain a constant heat flow 5or flu06across the vessel wall.

RESULT

Thus the performance stud in a refrigerator with calorimeter was thoroughl studied.

Documents

Basic Mechanical Engineering Lab Manual