Mehran

University

Department of Mechanical Engineering

Laboratory Workbook - 2024

Name: Roll No:

 MEHRAN UNIVERSITY OF ENGINEERING
&
TECHNOLOGY JAMSHORO

Department of Mechanical Engineering

CERTIFICATE

This is to certify that Mr./Ms. _______________________ S/O or

D/O ______________________ bearing Roll no. ___________ has
carried out all practical work of the _________________________
in _____ Semester, _____ Year of his/her B.E degree program
during the session _______________.

_____________ _________
Subject teacher Dated
 LABORATORY HEALTH/SAFETY OVERRVIEW &
GUIDELINES
Laboratory Title:

1 Familiarize yourself with the operation of all equipment and all hazards
involved, before commencing an experiment.
2 Always keep your work area(s) clean.
3 Never leave an ongoing experiment unattended.
4 Make sure you are aware of where your lab's exits and fire alarms are located.
5 If you notice any unsafe conditions in the lab, let your instructor know as soon
as possible.
6 All equipment should be regularly inspected for wear or deterioration.
7 If something goes wrong, do not panic. Think, take your time, and then act.
You must know how to stop a machine in an emergency mode.
8 Only materials you require for your work should be kept in your work area.
Everything else should be stored safely out of the way.
9 Before using any high voltage equipment, make sure you get permission from
your lab supervisor.
10 Ensure Voltage safe level, before operating any device.
11 Always turn off a high voltage power supply when you are attaching it.
12 Make sure all electrical panels are unobstructed and easily accessible.
13 Make sure all the power sockets in the laboratory are fused.
14 Avoid wearing loose clothing when working on rotary equipment.
15 Wear necessary PPE where ever required during experimental session.
16 Educate yourself regarding equipment maximum rating. Never operate any
equipment beyond its operating limits.
17 Do not throw wrappers and/or any other waste material in the laboratory.
18 Avoid playing with the tools present in the laboratory
19 Long hair (chin-length or longer) must be tied to avoid catching fire.
20 Safety is a mutual responsibility and requires the full co-operation of everyone
in the laboratory.
21 Any equipment that requires air flow or ventilation to prevent overheating
should always be kept clear.
22 Keep the fire exit way always clear.
 MEHRAN UNIVERSITY OF ENGINEERING AND TECHNOLOGY, JAMSHORO
DEPARTMENT OF MECHANICAL ENGINEERING.
Title of Subject THERMODYNAMICS – II
Course Code (ME 242)
Semester FOURTH Year : SECOND
Discipline MECHANICAL
Effective 22 Batch and onwards
Pre-requisite Thermodynamics-I (ME 222)
Co-requisite ------
Theory Practical
Assessment 20% Sessional Work, 50% Sessional Work,
30% Mid Semester Examination -------------,
50% Final Written Examination 50% Final Lab. Examination
Credit Hours Theory 03 Practical 01
Marks Theory 100 Practical 50

After Completing the “Thermodynamics-II” Course, each student will be able to:

CLO Domain Taxonomy

No.
Description Level
PLO
Illustrate the construction and operation of different
1 Cognitive 2 1
components involved in thermal systems
Analyze operating and performance parameters of different
3 Cognitive 4 2
devices used in Thermal systems.
Measure various quantities to evaluate performance of
4 Psychomotor 4 2
different devices used in Thermal systems

RELEVANT PROGRAM LEARNING OUTCOMES (PLOs):

The course is designed so that students will achieve the following PLOs:
√
1 Engineering Knowledge 7 Environment and Sustainability:
√
2 Problem Analysis: 8 Ethics:
Design/Development of
3 9 Individual and Team Work:
Solutions:
4 Investigation: 10 Communication:
5 Modern Tool Usage: 11 Project Management:
6 The Engineering Society: 12 Lifelong Learning:
 MEHRAN UNIVERSITY OF ENGINEERING &TECHNOLOGY, JAMSHRO
Department of Mechanical Engineering
CLOs for Lab.

Subject (with code) Semester Teacher Name Credit hr.

Thermodynamics II
4TH Engr. Ashfaque Ahmed 01
(ME 242)
Learning
S. No CLO statement Level PLO
Domain
01 Measure various quantities to evaluate performance Psychomotor 4 2
of different devices used in Thermal systems

DISTRIBUTION OF CLOs MARKS (for 22 ME Batch)

Sessional Work
Final Exam
Total
CLO# Final Remarks
Viva / Marks
Workbook Lab work OEL Exam
conduct lab
Test
CLO-1 06 09 10 15 10
50
Total Marks 25 25

TL = Traditional lab or Closed-ended lab

OEL = Open-Ended Lab / Mini project
 TABLE OF CONTENTS

Lab
Page
Session Objective CLO PLO
No.
No.
1 To demonstrate different parts, working mechanism, single stage air 1 1,2
compressor test unit.
2 To demonstrate different parts and working mechanism of two stage 1 1,2
reciprocating air compressor.
3 To measure the variation in air volume flow rate at different compressor 1 1,2
pressure ratio: without intercooling.
4 To measure the variation in volumetric efficiency at different compressor 1 1,2
pressure ratio: without intercooling.
5 To investigate the double stage compressor performance relative to 1 1,2
electric power: without intercooling.
6 To demonstrate construction and working of saturation pressure unit / 1 1,2
Marcet boiler
7 To measure saturation pressure and temperature using saturation 1 1,2
pressure unit and to compare the experimental values with the theoretical
values.
Open Ended Lab

8 To investigate the pressure distribution in convergent nozzle when 1 1,2

operating at different pressure ratios.
9 To evaluate the choking condition in convergent nozzle 1 1,2

10 To investigate the pressure distribution in convergent-Divergent nozzle 1 1,2

when operating at different pressure ratios.
11 To evaluate the choking condition in convergent-Divergent nozzle 1 1,2

12 To demonstrate impulse turbine unit & calculate mechanical power, 1 1,2

hydraulic power and impulse turbine efficiency at different values of
braking torque.
13 To investigate the effect of nozzle pressure on the hydraulic power, 1 1,2
mechanical power and impulse turbine efficiency.
14 To investigate the effect of number of nozzles on the hydraulic power, 1 1,2
mechanical power and impulse turbine efficiency.
Open Ended Lab
 ASSESSMENT RUBRIC FOR PRACTICAL OF THERMODYNAMICS-II
(MAX. MARKS = 50 FOR 1CH)

S# TAXONOMY
COURSE LEARNING OUTCOMES
LEVEL
Measure various quantities to evaluate performance of different devices
01 P4, A4, C1
used in Thermal systems

I. SESSIONAL MARKS (Max. Marks = 25)

DISTRIBUTION OF MARKS ASSESSOR
a. OEL / Mini Project
(Max. Marks 10) Internal examiner

b. Practical Journal / Workbook of Thermodynamics-II

(Max. Marks 06) Internal examiner

c. Performance of Lab work

(Max. Marks = 09) Internal examiner

MINI PROJECT / OPEN ENDED LAB (Max. Marks 10)

CRITERIA & MARKS

HIGH (2-4 MARKS) LOW (0-1 MARK)
WIGHTAGE SECURED
Key concepts of the project Key concepts are clear, but
1. Design concepts and
are clear, and all the Objective Objective are not properly
Objective (04 marks)
are described described
2. Physical implementation Hardware is in working Hardware built is complete,
of design (03 marks) condition and properly but project is not working
demonstrated properly
3. Results and report (03 Desired results are achieved, Desired results are not fully
marks) and project report is according achieved but project report is
to the given format according to the given format
LABORATORY PERFORMANCE AND WORKBOOK MARKS
(MAX: MARKS 15) SECURED
PRACTICAL JOURNAL / WORKBOOK (06)
PERFORMANCE OF LAB WORK (09)
TOTAL MARKS SECURED.
 II. FINAL SEMESTER LAB EXAM (MAX. MARKS 25)
DISTRIBUTION OF MARKS ASSESSOR
Internal examiner
a. Final Exam Test (Max. Marks 15)
External examiner
Internal examiner
b. Conduct of Practical (Max. Marks 10)
External examiner

FINAL EXAM TEST

TAXONOMY MARKS
CRITERIA & WIGHTAGE REMARKS
LEVEL SECURED
1. Knowledge, clarity, application of concepts of Excellent (8-15)
Thermodynamics-II and use of C1 Good (4-7)
instrument/equipment/tools in Thermodynamics
laboratory (15) Average (0-3)

CONDUCT OF PRACTICAL VIVA

TAXONOMY MARKS
CRITERIA & WIGHTAGE REMARKS
LEVEL SECURED
Excellent (4)
1. Adoption of safety precautions, set up and care
of instrument/equipment/tools used in A4 Good (3)
Thermodynamics laboratory (04) Average (1)
Excellent (3)
2. Follow up of experimental procedure (03) P4 Good (2)
Average (1)

3. Data collection, analysis, results, conclusion, Excellent (3)

and hands-on activities with P4 Good (2)
instrument/equipment/tools used. (03) Average (1)
 LAB SESSION NO. 01

OBJECTIVE

To demonstrate different parts and working mechanism of single stage air compressor
test unit.

EQUIPMENT/PARTS REQUIRED:

Single stage air cooled compressor test unit.

Fig. 1.1 Air Compressor test unit

WORKING MECHANISM:

The single stage reciprocating air compressor the entire compression is carried out in a
single cylinder. If the compression is affected in one end of the piston & cylinder then
it is known as single acting.

When piston starts moving downwards, the pressure inside the cylinder falls below
atmospheric pressure& suction valve/inlet valve opens. The air is drawn into the
cylinder through suction filter element. This operation is known as suction stroke.

When piston moves upwards, compresses the air in cylinder & inlet valve closes when
pressure reaches to atmospheric pressure. Further compression follows as the piston
moves towards the top of its stroke until, when the pressure in the cylinder exceeds that
in the receiver. This is compression stroke of compressor. At the end of this stroke
discharge/delivery valve opens & air is delivered to receiver.

Thermodynamics-II Page 1 of 72
DESCRIPTION: This test unit includes air compressor set

Fig. 1.2 Components of single stage air compressor unit

Thermodynamics-II Page 2 of 72
USEFUL DATA/SPECIFICATION:

Bore × stroke-No. of cylinder 72mm × 65mm-1

Discharge air flow rate (max.)

180 L/min

Discharge pressure (max)

7kg/cm2xG

Drive motor output

1.5KW (unloaded)

Receiver (air tank) capacity

38 liters

Thermodynamics-II Page 3 of 72
Post Lab Activity:

1. Define air compressor and enlist the applications of air compressor or

compressed air?

_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

2. Differentiate single acting and single stage air compressor?

___________________________________________________________
___________________________________________________________
___________________________________________________________
___________________________________________________________
___________________________________________________________

Thermodynamics-II Page 4 of 72
 LAB SESSION NO. 02

OBJECTIVE

To demonstrate different parts and working mechanism of two stage reciprocating air
compressor.

EQUIPMENT/PARTS REQUIRED:

Two Stage Compressor Test Unit.

DESCRIPTION:

This test unit includes the compressor module and a control console.

CONTROL CONSOLE:

Fig. 2.1 (Control console front panel)

ID# Description ID# Description

1 Main Switch 6 Compressor voltmeter

2 Tachometer lead 7 Temperature indicator

3 Motor tachometer 8 Temperature selector switch

4 Orifice plate manometer 9 Thermo couple sockets

5 Compressor ammeter -

Thermodynamics-II Page 5 of 72
 Fig. 2.2 (Control console rear panel)

ID# Description ID# Description

2.5A MAX power outlet for

10 Main power inlet 12
optional data logger

Port for optional data logger

11 13 Power outlet for Compressor
upgrade

COMPRESSOR MODULE:

Fig.2.3 (Compressor Module)

Thermodynamics-II Page 6 of 72
 ID# Description ID# Description
14 Compressor 15 Motor
16 Cooling water flow meter 17 1st stage pressure gauge
18 1st stage receiver 19 1st stage safety valve (4 Bar)
20 2nd stage pressure gauge 21 2nd stage safety valve (11 Bar)
22 Intake Orifice /Damping vessel 23 Intercooler
24 Valve “A” 25 Valve “B”
26 Water purge valve 27 2nd stage receiver
28 1st stage intake pipe 29 1st stage discharge
30 2nd stage intake 31 2nd stage discharge

WORKING MECHANISM:

The compressor (14) is mounted together with its drive motor (15) on top of the 2nd
stage air receiver (27).
Air is drawn into the unit through the intake orifice/damping vessel (22) attached to the
1st stage intake pipe (28) on the compressor.
The orifice plate is connected to the orifice plate manometer (4) mounted on the front
panel of the separate control console.
The compressor is a twin cylinder device (two cylinders in parallel) with one cylinder
taking air in at the intake (28) and compressing to an intermediate pressure and air then
leaves the 1st stage discharge (29) to the 1st stage receiver (18) and passes through the
water cooled intercooler (23). The air passes to the 2nd stage intake (30) for the final
stage compression. The air leaves the 2nd stage discharge (31) at high pressure and
passes to the 2nd stage receiver (27).
The intermediate pressure is shown by the 1st stage pressure gauge (17) and the 2nd stage
pressure is shown by the 2nd stage pressure gauge (20) on the receiver (27). The final
stage pressure can be controlled by adjusting the receiver discharge/vent valve (32) on
the end of the receiver.
The intercooler water flow rate is monitored and controlled by the flow meter (16). The
valve A (24) can be closed and valve B (25) opened to operate the unit as a single stage
compressor.

Thermodynamics-II Page 7 of 72
The motor speed is monitored by a sensor which connects directly to the motor
tachometer (3) display which is mounted on the front panel of the separate control
console.
As the compressed air is likely to contain moisture which will condense in the 2nd stage
air receiver (27) a drain valve is located under one end of the receiver.
The 1st stage receiver (18) is fitted with a safety valve (19) set to operate at 4 bar gauge.
This is primarily to prevent overloading of the motor due to the large diameter of the
low pressure cylinder.
The compressor is fitted with a high pressure switch (35). This is factory set to operate
at 10 bar gauge and is connected to the 2nd stage air receiver (27). The 2nd stage outlet
air receiver (27) has a safe working pressure of 11 bar gauge and a safety valve (21) is
also fitted to the receiver set to vent at 11 bar gauge.
The inlet to the 2nd stage air receiver (27) is fitted with a non-return valve and an
unloading valve. The combined high pressure switch also has an unloading device that
allows the compressor to start under zero pressure conditions even when the 2nd stage
air receiver (27) is at high pressure. This prevents overloading of the compressor motor
and ensures a long operating life.

The compressor Green on switch and Red stop switch are both located on top of the
high pressure switch these are the main compressor controls.

USEFUL DATA:
Compressor dimensions
Cylinders 2
Low Pressure Cylinder
Bore 95mm
Stroke 50mm
High Pressure Cylinder
Bore 50mm
Stroke 50mm

Swept volume per revolution 0.3544x10-3 m3

Thermodynamics-II Page 8 of 72
Post Lab activity:

1. Enlist any four factors considered for selection of an air compressor and
explain the importance of each factor.
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________

2. What are advantages and disadvantages of single acting and double

acting air compressors?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________

Thermodynamics-II Page 9 of 72
 LAB SESSION NO. 03

OBJECTIVE:

To measure the variation in air flow rate, at different compressor pressure ratio:
without intercooling.

EQUIPMENT/PARTS REQUIRED:
Two Stage Compressor Test Unit.
THEORY:
Compressors use a mechanical power input to increase the pressure of a compressible
fluid (i.e., to reduce its specific volume). There are many different types of
compressors, e.g., reciprocating, rotary vane, scroll, screw, and centrifugal
compressors. The reciprocating compressor is positive displacement compressor
because they displace a fixed volume of fluid during each cycle.

In a reciprocating compressor the fluid enters the compressor cylinder through an

inlet valve as the piston is moved to the down in order to increase the volume in the
cylinder. The inlet valve closes when the piston reaches the end of its stroke. The fluid
pressure increases as the piston is then moved to the up in order to reduce the volume
of gas in the cylinder. The outlet valve eventually opens so that the piston pushes the
high pressure fluid out.

Compressors may also be classified on the basis of number of stages. Compressors can
be single stage or multistage. In a single stage system the air is compressed once and
in a dual stage the air is compressed twice.

In a single stage piston compressor the air is drawn into a cylinder and compressed
in a single piston stoke to a pressure. Then it is send to the storage tank.

In a dual stage compressor the first step is the same except that the air is not directed
to the storage tank, the air is sent via an inter cooler tube to a second, smaller high
pressure piston and compressed a second time and compressed to a higher pressure.
Then it is sent through the after cooler to the storage tank.

Thermodynamics-II Page 10 of 72
PROCEDURE:

1. Ensure that the receiver discharge /vent valve is fully open. Check that the drain
valve at the base of the outlet air receiver is closed.
2. Fully open valve A (24) (turn anti-clockwise) and fully close valve B (25) (turn
clockwise).
3. Intercooling is not required close the cooling water flow meter (16) valve fully.
4. Adjust the orifice plate manometer (4) scale to zero. Turn on the main switch (1)
on the control console and the instruments will illuminate.
5. Finally press the green compressor ON switch on the high pressure switch, on the
compressor module and the compressor will start. Air should be heard venting from
the receiver discharge/vent valve (32) AND from the high pressure switch area.
This is normal.

6. Increase the outlet pressure to approximately 100-150kN/m2 by closing the receiver

discharge/vent valve (32).
nd
7. When the pressure has reached the desired level slowly open the 2 stage
discharge/vent valve (32) until the pressure is stable. This may take several
attempts. There is a delay of several seconds after each adjustment has an effect on
the discharge pressure.

8. Increase the outlet pressure by amounts 100-150kN/m2and repeat the observations.

OBSERVATION TABLE:
Ambient Pressure1.01Bar (101.325 kPa)

Sample No. 1 2 3

Inlet temperature t1/°C

st
Air out of 1 stage t2/°C
nd
Air into 2 stage t3/°C
nd
Air out of 2 stage t4/°C
st 2
1 stage pressure P1/kN/m
nd 2
2 stage pressure P2/kN/m

Manometer Height h/mm

Thermodynamics-II Page 11 of 72
Air volume flow rate measurement or actual swept volume flow rate (m3/s):

qv = 5.670 × 10−5 √h × (t1 + 273.16) (m3/s)

h = Orifice plate manometer pressure mmWg

CALCULATIONS:

Thermodynamics-II Page 12 of 72
 Variables 1 2 3
Air flow rate
(m3/sec)
st
1 stage Pressure ratio
nd
2 stage Pressure ratio
Overall Pressure Ratio

Plot the graph between air volume flow rate (y) and overall Pressure Ratio (x).

CONCLUSION:

_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

Thermodynamics-II Page 13 of 72
Post Lab activity:

1. What is the importance of intercooling in compressor?

_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

2. How compressors are cooled?

_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

Thermodynamics-II Page 14 of 72
 LAB SESSION NO. 04

OBJECTIVE:

To measure the variation in volumetric efficiency at different compressor pressure

ratio: without intercooling.

EQUIPMENT/PARTS REQUIRED:
Two Stage Compressor Test Unit.
THEORY:
Compressors use a mechanical power input to increase the pressure of a compressible
fluid (i.e., to reduce its specific volume). There are many different types of
compressors, e.g., reciprocating, rotary vane, scroll, screw, and centrifugal
compressors. The reciprocating compressor is positive displacement compressor
because they displace a fixed volume of fluid during each cycle.

In a reciprocating compressor the fluid enters the compressor cylinder through an

inlet valve as the piston is moved to the down in order to increase the volume in the
cylinder. The inlet valve closes when the piston reaches the end of its stroke. The fluid
pressure increases as the piston is then moved to the up in order to reduce the volume
of gas in the cylinder. The outlet valve eventually opens so that the piston pushes the
high pressure fluid out.

Compressors may also be classified on the basis of number of stages. Compressors can
be single stage or multistage. In a single stage system the air is compressed once and
in a dual stage the air is compressed twice.

In a single stage piston compressor the air is drawn into a cylinder and compressed
in a single piston stoke to a pressure. Then it is send to the storage tank.

In a dual stage compressor the first step is the same except that the air is not directed
to the storage tank, the air is sent via an inter cooler tube to a second, smaller high
pressure piston and compressed a second time and compressed to a higher pressure.
Then it is sent through the after cooler to the storage tank.

Thermodynamics-II Page 15 of 72
PROCEDURE:

1. Ensure that the receiver discharge /vent valve is fully open. Check that the drain
valve at the base of the outlet air receiver is closed.
2. Fully open valve A (24) (turn anti-clockwise) and fully close valve B (25) (turn
clockwise).
3. Intercooling is not required close the cooling water flow meter (16) valve fully.
4. Adjust the orifice plate manometer (4) scale to zero. Turn on the main switch (1)
on the control console and the instruments will illuminate.
5. Finally press the green compressor ON switch on the high pressure switch, on the
compressor module and the compressor will start. Air should be heard venting from
the receiver discharge/vent valve (32) and from the high pressure switch area. This
is normal.

6. Increase the outlet pressure to approximately 100-150 kN/m2 by closing the receiver
discharge/vent valve (32).

7. When the pressure has reached the desired level slowly open the2ndstage
discharge/vent valve (32) until the pressure is stable. This may take several
attempts. -There is a delay of several seconds after each adjustment has an effect
on the discharge pressure.

8. Increase the outlet pressure by amounts 100-150 kN/m2 and repeat the observations.

OBSERVATION TABLE:
Ambient Pressure1.01Bar (101.325 kPa)

Variable 1 2 3
Inlet temperature t1/°C
st
Air out of 1 stage t2/°C
nd
Air into 2 stage t3/°C
nd
Air out of 2 stage t4/°C
st 2
1 stage pressure P1/kN/m
nd 2
2 stage pressure P2/kN/m
Manometer Height h/mm
Speed RPM

Thermodynamics-II Page 16 of 72
Air flow measurement or Actual swept volume flow rate

𝑞𝑣 = 5.670 × 10−5 √ℎ × (𝑡1 + 273.16) (m3/s)

h = Orifice plate manometer pressure mmWg

Swept volume per revolution =0.3544x10-3 m3

Swept volume flow rate (m3/s)

𝑠𝑤𝑒𝑝𝑡 𝑣𝑜𝑙𝑢𝑚𝑒 𝑜𝑓 𝑐𝑜𝑚𝑝𝑟𝑒𝑠𝑠𝑜𝑟 ∗𝑅𝑃𝑀
𝑉𝑠 = 60
(m3/s)

Volumetric efficiency
𝐴𝑐𝑡𝑢𝑎𝑙 𝑠𝑤𝑒𝑝𝑡 𝑣𝑜𝑙𝑢𝑚𝑒 𝑓𝑙𝑜𝑤 𝑟𝑎𝑡𝑒 (𝑞𝑣 )
𝑉𝑜𝑙𝑢𝑚𝑒𝑡𝑟𝑖𝑐 𝑒𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑐𝑦 𝑜𝑓 𝑐𝑜𝑚𝑝𝑟𝑒𝑠𝑠𝑜𝑟 = 𝑠𝑤𝑒𝑝𝑡 𝑣𝑜𝑙𝑢𝑚𝑒 𝑓𝑙𝑜𝑤 𝑟𝑎𝑡𝑒 (𝑉𝑠)
*100%

CALCULATIONS:

Thermodynamics-II Page 17 of 72
 Variables 1 2 3

Volumetric efficiency of compressor, %

st
1 stage Pressure ratio
nd
2 stage Pressure ratio
Overall Pressure Ratio

Plot the graph between volumetric efficiency (y) and overall Pressure Ratio (x).

CONCLUSION:

_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

Thermodynamics-II Page 18 of 72
Post Lab activity:

1. Explain the working of feather valve in compressor?

_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

2. Why volumetric efficiency of a compressor decreases by increasing pressure

ratio?

_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

Thermodynamics-II Page 19 of 72
 LAB SESSION NO. 05

OBJECTIVE:

To investigate the double stage compressor performance relative to electric power:

without intercooling.

EQUIPMENT/PARTS REQUIRED:
Two Stage Compressor Test Unit.
THEORY:
Compressors use a mechanical power input to increase the pressure of a compressible
fluid (i.e., to reduce its specific volume). There are many different types of
compressors, e.g., reciprocating, rotary vane, scroll, screw, and centrifugal
compressors. The reciprocating compressor is positive displacement compressor
because they displace a fixed volume of fluid during each cycle.

In a reciprocating compressor the fluid enters the compressor cylinder through an

inlet valve as the piston is moved to the down in order to increase the volume in the
cylinder. The inlet valve closes when the piston reaches the end of its stroke. The fluid
pressure increases as the piston is then moved to the up in order to reduce the volume
of gas in the cylinder. The outlet valve eventually opens so that the piston pushes the
high pressure fluid out.

Compressors may also be classified on the basis of number of stages. Compressors can
be single stage or multistage. In a single stage system the air is compressed once and
in a dual stage the air is compressed twice.

In a single stage piston compressor the air is drawn into a cylinder and compressed
in a single piston stoke to a pressure. Then it is send to the storage tank.

In a dual stage compressor the first step is the same except that the air is not directed
to the storage tank, the air is sent via an inter cooler tube to a second, smaller high
pressure piston and compressed a second time and compressed to a higher pressure.
Then it is sent through the after cooler to the storage tank.

Thermodynamics-II Page 20 of 72
PROCEDURE:

1. Ensure that the receiver discharge /vent valve is fully open. Check that the drain
valve at the base of the outlet air receiver is closed.
2. Fully open valve A (24) (turn anti-clockwise) and fully close valve B (25) (turn
clockwise).
3. Intercooling is not required close the cooling water flow meter (16) valve fully.
4. Adjust the orifice plate manometer (4) scale to zero. Turn on the main switch (1)
on the control console and the instruments will illuminate.
5. Finally press the green compressor ON switch on the high pressure switch, on the
compressor module and the compressor will start. Air should be heard venting from
the receiver discharge/vent valve (32) and from the high pressure switch area. This
is normal.

6. Increase the outlet pressure to approximately 100-150 kN/m2 by closing the receiver
discharge/vent valve (32).
nd
7. When the pressure has reached the desired level slowly open the 2 stage
discharge/vent valve(32) until the pressure is stable. This may take several
attempts. -There is a delay of several seconds after each adjustment has an effect
on the discharge pressure.

8. Increase the outlet pressure by amounts 100-150kN/m2and repeat the observations.

OBSERVATION TABLE:
Ambient Pressure1.01Bar (101.325 kPa)
Variable 1 2 3
Inlet temperature t1/°C
st
Air out of 1 stage t2/°C
nd
Air into 2 stage t3/°C
nd
Air out of 2 stage t4/°C
st 2
1 stage pressure P1/kN/m
nd 2
2 stage pressure P2/kN/m
Manometer Height h/mm
Speed RPM
Voltage Volts
Current Ampere

Thermodynamics-II Page 21 of 72
Air flow measurement/Actual swept volume flow rate

𝑞𝑣 = 5.670 × 10−5 √ℎ × (𝑡1 + 273.16) (m3/s)

h = Orifice plate manometer pressure mmWg

Swept volume per revolution =0.3544x10-3 m3

Swept volume flow rate (m3/s)

𝑠𝑤𝑒𝑝𝑡 𝑣𝑜𝑙𝑢𝑚𝑒 𝑜𝑓 𝑐𝑜𝑚𝑝𝑟𝑒𝑠𝑠𝑜𝑟 ∗ 𝑅𝑃𝑀

𝑉𝑠 =
60

Volumetric efficiency
𝐴𝑐𝑡𝑢𝑎𝑙 𝑠𝑤𝑒𝑝𝑡 𝑣𝑜𝑙𝑢𝑚𝑒 𝑓𝑙𝑜𝑤 𝑟𝑎𝑡𝑒 (𝑞𝑣 )
𝑉𝑜𝑙𝑢𝑚𝑒𝑡𝑟𝑖𝑐 𝑒𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑐𝑦 𝑜𝑓 𝑐𝑜𝑚𝑝𝑟𝑒𝑠𝑠𝑜𝑟 = 𝑠𝑤𝑒𝑝𝑡 𝑣𝑜𝑙𝑢𝑚𝑒 𝑓𝑙𝑜𝑤 𝑟𝑎𝑡𝑒 (𝑉𝑠)
*100%

Electrical Power

𝑤𝑒𝑙𝑒𝑐𝑡𝑟𝑖𝑐𝑎𝑙 = √3 ∗ 𝑉 ∗ 𝐼 ∗ 𝐶𝑜𝑠∅
Where cosФ=power factor=0.85

V=voltage and I=current

CALCULATIONS:

Thermodynamics-II Page 22 of 72
 Variables 1 2 3

Actual swept volume flow rate (m3/s)

Volumetric efficiency of compressor, %

Electrical Power (Watt)

st
1 stage Pressure ratio
nd
2 stage Pressure ratio
Overall Pressure Ratio

Thermodynamics-II Page 23 of 72
Plot the graph between electrical power and overall Pressure Ratio.

CONCLUSION:

___________________________________________________________
___________________________________________________________
___________________________________________________________

Thermodynamics-II Page 24 of 72
Post Lab activity:

1. Explain the working of single phase and three phase induction motor?

___________________________________________________________
___________________________________________________________
___________________________________________________________

___________________________________________________________
___________________________________________________________
__________________________________________________________

2. Define the term power factor?

___________________________________________________________
___________________________________________________________
___________________________________________________________

Thermodynamics-II Page 25 of 72
 LAB SESSION NO. 06

OBJECTIVE

To demonstrate construction and working of saturation pressure unit: Marcet boiler.

EQUIPMENT/PARTS REQUIRED:

Saturation Pressure unit: Marcet Boiler

Fig. 6.1 Saturation Pressure unit

THEORY:

The marcet boiler made of stainless steel and equipped with a pressure gauge (𝑃11 ), two
water valves (𝑉1 and 𝑉2), a safety valve (𝑃𝑆𝑉1), and a thermo resistance pt100 (𝑇11 ) and
an electrical heater (𝐽1 ). This unit consists of a Marcet boiler that enables to analyze the
correlation between water temperature and pressure and to compare the experimental
data with those available in literature. The water stored in the boiler is heated by an
electric resistor; trends of temperature and pressure can be seen on a display and on a
Bourdon gauge.

Thermodynamics-II Page 26 of 72
 Fig. 6.2 Schematic diagram of saturation Pressure unit

PROCEDURE:

1. Place the unit on a firm, level bench or table

2. Connect the control box to the power supply
3. Insert the plug of the heater 𝐽1 in the socket on the rear of the control box
4. Close valve 𝑣1 and open valve 𝑣2
5. Connect valve 𝑣1 to the tap water using hose
6. Connect valve 𝑣2 to a suitable drain using hose
7. Open valve 𝑣2 partially to fill the boiler : when water overflow from valve 𝑣2 ,
close valve 𝑣1
8. Switch on the electrical heater 𝐽1
9. Wait for the steam flows out through the valve 𝑣2 to ensure that there is no air
trapped in the boiler, then, close valve 𝑣2 .
10. Record pressure and temperature in increments of approximately 1bar in a
data sheet table until the maximum pressure.

Thermodynamics-II Page 27 of 72
Post Lab activity:

1. Define the term boiler?

_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________

2. Explain the types of boiler along with their applications?

_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________

Thermodynamics-II Page 28 of 72
 LAB SESSION NO. 07

OBJECTIVE

To measure saturation temperature and saturation pressure of water using saturation

pressure unit and to compare the values with theoretical or published values.

EQUIPMENT/PARTS REQUIRED:

Saturation Pressure unit: Marcet Boiler

Fig. 7.1 Saturation Pressure Unit

THEORY:

The marcet boiler made of stainless steel and equipped with a pressure gauge (𝑃11 ), two
water valves (𝑉1 and 𝑉2), a safety valve (𝑃𝑆𝑉1), and a thermo resistance pt100 (𝑇11 ) and
an electrical heater (𝐽1 ). This unit consists of a Marcet boiler that enables to analyze the
correlation between water temperature and pressure and to compare the experimental
data with those available in literature. The water stored in the boiler is heated by an
electric resistor; trends of temperature and pressure can be seen on a display and on a
Bourdon gauge.

Thermodynamics-II Page 29 of 72
 Fig. 7.2 Schematic diagram of saturation Pressure unit

For a pure substance existing as mixture of two phases, the Clausis-Clapeyron

relationship relates the pressure, heat and expansion during a change of phase provided
that the two phase are in equilibrium. We can apply the Clausius-Clapeyron equation to
estimate the vapor pressure at any temperature and to estimate the heat of phase
transition from the vapor pressures measured at two temperatures. The Clausis-
Clapeyron relationship, for a system water-steam, is

𝑃 𝐻𝑣𝑎𝑝 1 1
𝐿𝑛 ( ) = ∗( − ) equation no. 1
𝑃0 𝑠𝑎𝑡 𝑅 𝑇0 𝑇 𝑠𝑎𝑡

Where:

Hvap=enthalpy of vaporization
for water Hvap @ 1 bar =40672 J/mol
T = absolute temperature
P = absolute pressure
R= gas constant =8.3145 J/mol*K

PROCEDURE:

1. Place the unit on a firm, level bench or table

2. Connect the control box to the power supply
3. Insert the plug of the heater 𝐽1 in the socket on the rear of the control box

Thermodynamics-II Page 30 of 72
 4. Close valve 𝑣1 and open valve 𝑣2
5. Connect valve 𝑣1 to the tap water using hose
6. Connect valve 𝑣2 to a suitable drain using hose
7. Open valve 𝑣2 partially to fill the boiler : when water overflow from valve 𝑣2 ,
close valve 𝑣1
8. Switch on the electrical heater 𝐽1
9. Wait for the steam flows out through the valve 𝑣2 to ensure that there is no air
trapped in the boiler, then, close valve 𝑣2 .
10. Record pressure and temperature in increments of approximately 1bar in a
data sheet table until the maximum pressure.

Sample calculation: To estimate saturation pressure of steam at saturation

temperature of 108ᵒC or 381 K using clausis-clayperon equation.
As we know vapor pressure of water at T0= 373[K] is P0=1.01325 bar
Using equation no. 1
Ln(P2/1.01325)=40672/8.3145*(1/373-1/381)
where T2 is experimental value of saturation temperature at saturation pressure
P2
P2=1.33 bar

CALCULATIONS:

Thermodynamics-II Page 31 of 72
OBSERVATIONS TABLE:

S.no Psaturation Psaturation

Tsaturation Psatuation
guage absolute
(ºC)+273= Absolute (bar)
(bar) (bar)
Experimental (Theoretical)
Experimental Experimental
value
value value
1. 1
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.

Thermodynamics-II Page 32 of 72
Plot between saturation pressure (y) and saturation temperature (x) of water for
theoretical and experimental results.

CONCLUSION:

_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

Thermodynamics-II Page 33 of 72
Post Lab activity:

1. Define saturation temperature and saturation pressure?

_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

2. Define critical temperature and critical pressure?

_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

Thermodynamics-II Page 34 of 72
 LAB SESSION NO. 08

OBJECTIVE
To investigate the pressure distribution in convergent nozzle when operating at
different pressure ratios.

EQUIPMENT/PARTS REQUIRED:

Nozzle pressure distribution unit.

THEORY:

The purpose of a nozzle is to convert a high-pressure fluid into a low-pressure fluid

with a higher velocity. It has varying cross-sectional area along its length. Nozzles are
classified convergent nozzle and convergent-divergent nozzle. The flow area of the
duct decreases along the length, such ducts are called converging nozzles. The velocity
of the fluid in a converging nozzle never exceeds the speed of sound.The flow through
a converging nozzle is governed by the back pressure Pb (the pressure applied at the
nozzle discharge region).
PROCEDURE:

1. Connect the equipment (Figure 6.2) to compressed air (up to 9 bar) supply.
2. Using inlet pressure control valve, set the inlet pressure to 6.6 bar.
3. Using outlet pressure control valve (needle valve), set the back pressure.
4. Note the set pressures, nozzle pressures, temperatures and mass flow.
5. Gradually increase the back pressure and note values.

Fig. 8.1 (Dimensions of Converging Nozzle used for experiment)

Thermodynamics-II Page 35 of 72
 Nozzle Type: Convergent Nozzle

Page 36 of 72
Mass
Pin Tin Pout Tout P1 P2 P3 P4 P5 P6 P7 P8
S.No Pin/Pout flow
(bar) (°C) (bar) (°C) (bar) (bar) (bar) (bar) (bar) (bar) (bar) (bar)
(g//sec)
6.6 (g/sec
1
)
2 6.6
3 6.6
4 6.6
5 6.6
OBSERVATION TABLE:

6 6.6

Thermodynamics-II
7 6.6
8 6.6
X 7 9.48 11.96 14.44 16.92 19.4 22.07 24.55
(mm)
Plot the graph between pressure points against the length of nozzle (X).

CONCLUSION:

_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

Thermodynamics-II Page 37 of 72
Post Lab Activity:

1. What are the applications of nozzles?

_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

2. What is significance of investigating pressure distribution in nozzles?

_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

Thermodynamics-II Page 38 of 72
 LAB SESSION NO. 09

OBJECTIVE

To evaluate the choking condition in convergent Nozzle.

EQUIPMENT/PARTS REQUIRED:

Nozzle pressure distribution unit

THEORY:

When the back pressure is equal to the inlet pressure, then no fluid can flow through
the nozzle. As the back pressure is reduced the mass flow through the nozzle increases.
However, when the back pressure reaches the critical value, it is found that no further
reduction in back pressure can affect the mass flow. When back pressure is equal to the
critical pressure, then velocity at exit is sonic and the mass flow through nozzle is at a
maximum and the condition is called as choked condition. The maximum mass flow
through a convergent nozzle is obtained when the pressure ratio across the nozzle is
equal to the critical pressure ratio.

The ratio of the pressure at the section where sonic velocity is attained to the inlet
pressure of nozzle is called the critical pressure ratio. It can be find as below

𝛾
𝑃𝑐 2 𝛾−1
=( )
𝑃𝑖 𝛾+1
Where,

𝛾 = 𝑟𝑎𝑡𝑖𝑜 𝑜𝑓 𝑠𝑝𝑒𝑐𝑖𝑓𝑖𝑐 ℎ𝑒𝑎𝑡𝑠, 𝑓𝑜𝑟 𝑎𝑖𝑟 𝑖𝑠 1.4

PROCEDURE:

1. Connect the equipment (Figure 6.2) to compressed air (up to 9 bar) supply.
2. Using inlet pressure control valve, set the inlet pressure to 6.6 bar,
3. Using outlet pressure control valve (needle valve). set the back pressure initially
5.4 bar.
4. Note the mass flow.
5. Reduce the back pressure by 0.4 bar and note the values.

Thermodynamics-II Page 39 of 72
 Fig. 9.1 (Dimensions of converging nozzle used for experiment)

OBSERVATION TABLE:

S.No Pin (bar) Pout (bar) Mass flow (g/sec)

1 6.6

2 6.6

3 6.6

4 6.6

5 6.6

6 6.6

7 6.6

8 6.6

9 6.6

10 6.6

Thermodynamics-II Page 40 of 72
Plot the graph between back pressure (x) and the mass flow rate (y).

CONCLUSION:

_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

Thermodynamics-II Page 41 of 72
Post Lab Activity:

1. Enlist the types of Nozzles?

_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

2. Define critical pressure in nozzles?

_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

Thermodynamics-II Page 42 of 72
 LAB SESSION NO. 10

OBJECTIVE

To investigate the pressure distribution in convergent-divergent nozzle operating at

different pressure ratios.

EQUIPMENT/PARTS REQUIRED:

Nozzle Pressure Distribution Unit

THEORY:

The purpose of a nozzle is to convert a high pressure fluid into a low pressure fluid with
a higher velocity. It has varying cross-sectional area along its length. Nozzles are
classified convergent nozzle and convergent-divergent nozzle. The flow area of the
duct first decreases and then increases, such ducts are called converging–diverging
nozzles. These nozzles are used to accelerate gases to supersonic speeds. For given inlet
conditions, the flow through a converging–diverging nozzle is governed by the back
pressure Pb (the pressure applied at the nozzle discharge region).

PROCEDURE:

1. Connect the equipment (Figure 6.2) to compressed air (up to 9 bar) supply.
2. Using inlet pressure control valve, set the inlet pressure to 6.6 bars.
3. Using outlet pressure control valve (needle valve), set the back pressure.
4. Note the set pressures, nozzle pressures, temperatures and mass flow.
5. Gradually increase the back pressure and note values.

Thermodynamics-II Page 43 of 72
 Fig. 10.1 (Dimensions of C-D Nozzle used for experiment)

LABEL THE FIGURE

Fig. 10.2 Nozzle Pressure distribution unit

1 5
2 6
3 7
4

Thermodynamics-II Page 44 of 72
 Page 45 of 72
Nozzle Type: convergent and divergent
Tin Pout Tout P1 P2 P3 P4 P5 P6 P7 P8 Mass flow
S.No Pin (bar) Pin/Pout
(°C) (bar) (°C) (bar) (bar) (bar) (bar) (bar) (bar) (bar) (bar) (g/sec)
1 6.6
2 6.6
3 6.6
4 6.6
5 6.6
6 6.6
OBSERVATION TABLE:

7 6.6

Thermodynamics-II
8 6.6
X 3 6 8.48 10.96 13.44 15.92 18.59 21.07
(mm)
Plot the graph between pressure points against the length of nozzle (x).

CONCLUSION:

_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

Thermodynamics-II Page 46 of 72
Post Lab Activity:

1. Define back pressure in nozzles?

_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

2. Define chocking in nozzles?

_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

Thermodynamics-II Page 47 of 72
 LAB SESSION NO. 11

OBJECTIVE

To evaluate the choking condition in convergent-divergent nozzle

EQUIPMENT/PARTS REQUIRED:

Nozzle pressure distribution unit.

THEORY:

When a nozzle operates with the maximum mass flow it is said to be choked. A
correctly designed convergent-divergent nozzle is always choked.

The maximum mass flow through a convergent-divergent nozzle is obtained when the
pressure at throat reaches critical pressure (M =1) by setting the back pressure in correct
range.

The ratio of the pressure at the section where sonic velocity is attained to the inlet
pressure of nozzle is called the critical pressure ratio. It can be find as below

𝛾
𝑃𝑐 2 𝛾−1
=( )
𝑃𝑖 𝛾+1
Where,

𝛾 = 𝑟𝑎𝑡𝑖𝑜 𝑜𝑓 𝑠𝑝𝑒𝑐𝑖𝑓𝑖𝑐 ℎ𝑒𝑎𝑡𝑠, 𝑓𝑜𝑟 𝑎𝑖𝑟 𝑖𝑠 1.4

PROCEDURE:

1. Connect the equipment to compressed air (up to 9 bar) supply.

2. Using inlet pressure control valve, set the inlet pressure to 6.6 bar,
3. Using outlet pressure control valve (needle valve), set the back pressure initially 6
bar.
4. Note the mass flow.
5. Reduce the back pressure by 0.4 bar and note the values.

Thermodynamics-II Page 48 of 72
 Fig. 11.1 (Dimensions of C-D Nozzle used for experiment)

OBSERVATION TABLE:

Pin (bar) Pthroat or P2 Pout Mass flow (g/sec)

S.No
(bar) (bar)

1 6.6

2 6.6

3 6.6

4 6.6

5 6.6

6 6.6

7 6.6

8 6.6

9 6.6

10 6.6

Thermodynamics-II Page 49 of 72
Plot the graph between back pressure (x) against the mass flow rate.

CONCLUSION:
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

Thermodynamics-II Page 50 of 72
Post Lab Activity:

1. Write the equation which governs shape of nozzle?

_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

2. Define Mach number?

_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

Thermodynamics-II Page 51 of 72
 LAB SESSION NO. 12 (a)

OBJECTIVE:

To demonstrate impulse turbine unit

EQUIPMENT/PARTS REQUIRED:

Impulse turbine demonstration unit.

THEORY:

Turbine is a rotary mechanical device that extracts energy from a fluid flow and
converts it into useful work. There are two common types of turbines, impulse turbine
and reaction turbine.

In an impulse turbine fluid is sent through a nozzle that then impinges on the rotating
blades, called buckets. The energy to rotate an impulse turbine is derived from the
kinetic energy of the steam flowing through the nozzle. The potential energy is
converted into kinetic energy when it passes through the nozzle. The velocity of steam
is reduced when it passes over the blades.

In a reaction turbine, nozzle is not used. There are two rows of moveable blades are
separated by one row of fixed blades. Fixed blades are attached to the casing & act as
nozzles. Blades are like the wings of a plane. Velocity of steam is increased when it
passes through the fixed blades. The steam pressure is reduced during its flow through
the moving blades.

Thermodynamics-II Page 52 of 72
 Fig. 12.1 Working of impulse and reaction turbine

PROCEDURE:

1. Switch on master switch.

2. Adjust pressure regulator to approx. 3 bar initial pressure
3. Fully open all 4 nozzles and valve for the air cooling.
4. Undo loading device and slowly increase nozzle pressure to 1.5 bar using fine
regulation valve.
5. Turbine runs up until it has reached its no-load speed. At a speed of more than
40000 rpm (over speed), a rapid stop triggered.
6. Using the loading device brake the turbine in steps and note speed, torque,
nozzle pressure, temperature and air volumetric flow rate.
7. Ensure that the nozzle pressure is constant; otherwise readjust the fine
regulation valve.

Thermodynamics-II Page 53 of 72
 Fig. 12.2 (Impulse Turbine Demonstration Unit)

LABEL THE FOLLOWING FIGURE:

Fig. 12.3 (Impulse turbine demonstration unit)

Thermodynamics-II Page 54 of 72
 ID# Description ID# Description
1 Base Frame 2 Thermocouple
3 Glass cone flow meter 4 Outlet manometer
5 Selection switch for temperature 6 Temperature display
point
7 Load unit with force transducer 8 Torque display
9 Speed display 10 Inlet manometer
11 Pressure regulator with filter 12 Fine regulation valve for
volumetric flow rate
13 Shut-off valve for air cooling 14 Impulse turbine
15 Ball cock for nozzle shut off -

Thermodynamics-II Page 55 of 72
Post Lab Activity:

1. What are the disadvantages of impulse turbine?

_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

2. What are the disadvantages of reaction turbine?

_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

Thermodynamics-II Page 56 of 72
 LAB SESSION NO. 12 (b)

OBJECTIVE:

To calculate mechanical power, hydraulic power and impulse turbine efficiency at

different values of braking torque.

EQUIPMENT/PARTS REQUIRED:

Impulse turbine demonstration unit.

THEORY:

Turbine is a rotary mechanical device that extracts energy from a fluid flow and
converts it into useful work. There are two common types of turbines, impulse turbine
and reaction turbine.

In an impulse turbine fluid is sent through a nozzle that then impinges on the rotating
blades, called buckets. The energy to rotate an impulse turbine is derived from the
kinetic energy of the steam flowing through the nozzle. The potential energy is
converted into kinetic energy when it passes through the nozzle. The velocity of steam
is reduced when it passes over the blades.

In a reaction turbine, nozzle is not used. There are two rows of moveable blades are
separated by one row of fixed blades. Fixed blades are attached to the casing & act as
nozzles. Blades are like the wings of a plane. Velocity of steam is increased when it
passes through the fixed blades. The steam pressure is reduced during its flow through
the moving blades.

Thermodynamics-II Page 57 of 72
 Fig. 13.1 working of impulse and reaction turbine

PROCEDURE:

8. Switch on master switch.

9. Adjust pressure regulator to approx. 3 bar initial pressure
10. Fully open all 4 nozzles and valve for the air cooling.
11. Undo loading device and slowly increase nozzle pressure to 1.5 bar using fine
regulation valve.
12. Turbine runs up until it has reached its no-load speed. At a speed of more than
40000 rpm (over speed), a rapid stop triggered.
13. Using the loading device brake the turbine in steps and note speed, torque,
nozzle pressure, temperature and air volumetric flow rate.
14. Ensure that the nozzle pressure is constant; otherwise readjust the fine
regulation valve.

Thermodynamics-II Page 58 of 72
 Fig. 13.2 (Impulse Turbine Demonstration Unit)

LABEL THE FOLLOWING FIGURE:

Fig. 13.3 (Impulse turbine demonstration unit)

Thermodynamics-II Page 59 of 72
 ID# Description ID# Description
1 Base Frame 2 Thermocouple
3 Glass cone flow meter 4 Outlet manometer
5 Selection switch for temperature 6 Temperature display
point
7 Load unit with force transducer 8 Torque display
9 Speed display 10 Inlet manometer
11 Pressure regulator with filter 12 Fine regulation valve for
volumetric flow rate
13 Shut-off valve for air cooling 14 Impulse turbine
15 Ball cock for nozzle shut off -

OBSERVATION TABLE:

Nozzle Pressure Pd = 1.5 bar

Inlet Outlet Volumetric

Speed Moment
S.No Temperature Temperature Flow rate
N (rpm) Md (N.cm)
T1 (oC) T2 (oC) V (%)

The mechanical Power is calculated from Torque in N.cm and speed in rpm.

Pmechanical=Torque*angular speed

𝑀𝑑 × 2 × 𝑛 × 𝜋
𝑃∗𝑚𝑒𝑐ℎ = (𝑊)
100 × 60

Thermodynamics-II Page 60 of 72
Note: Where Md is taken with unit (N.cm)

The hydraulic input power is calculated from nozzle pressure in Pascal and
volumetric flow rate in m3/sec.

In case of the volumetric flow rate, 100% on the display signifies a volumetric
flow rate 315 l/min or 0.00525 m3/sec

Phydrualic=Nozzle inlet pressure (Pa) *Volume flow rate (m3/s)

The very low outlet pressure can be ignored.

𝑃ℎ𝑦𝑑 = 𝑃𝑑 . 𝑉 (W)

The Efficiency can be calculated from the ratio of mechanical to hydraulic power.

𝑃𝑚𝑒𝑐ℎ
𝜂=
𝑃ℎ𝑦𝑑

CALCULATIONS:

Thermodynamics-II Page 61 of 72
 Hydr:
Speed n Moment Md Mech. Power Volumetric Efficiency
Power Phyd
(rpm) (N.cm) Pmech (W) Flow rate V (%) 𝜼 (%)
(W)

1. Plot the graph between Speed (x) and mechanical power (y).

Thermodynamics-II Page 62 of 72
2. Plot the graph between Speed (x) and Torque (y)

3. Plot the graph between Speed (x) and Efficiency (y)

CONCLUSION:

_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

Thermodynamics-II Page 63 of 72
Post Lab Activity:

1. Define the term turbine?

_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

2. Explain the working of impulse turbine?

_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

Thermodynamics-II Page 64 of 72
 LAB SESSION NO. 13

OBJECTIVE

To investigate the effect of nozzle pressure on the hydraulic power, mechanical power
and impulse turbine efficiency.

EQUIPMENT/PARTS REQUIRED:

Impulse turbine demonstration unit

PROCEDURE:

1. Fully open all 4 nozzles and the valve for the air cooling
2. Undo loading device and adjust nozzle pressure to 0.5 bar using fine
regulation valve.
3. Using the loading device, brake the turbine to a speed of 16500 rpm. Note
torque, nozzle pressure and air volumetric flow rate.
4. Increase nozzle pressure in step up to 1.5-2.0 bar and brake turbine using
braking devices to 16500 rpm

Fig. 14.1 (Impulse turbine demonstration unit)

Thermodynamics-II Page 65 of 72
OBSERVATION TABLE:

Nozzle Moment Power Volumetric Efficiency 𝜂 Phyd

Pressure 𝑴𝒅 in 𝑷𝒎𝒆𝒄𝒉 in flow in % Hydraulic
𝑷𝒅 in bar N.cm Watt Rate in % power,
Watt

The mechanical Power is calculated from Torque in N.cm and speed in rpm.

Pmechanical=Torque*angular speed

𝑀𝑑 × 2 × 𝑛 × 𝜋
𝑃∗𝑚𝑒𝑐ℎ = (𝑊)
100 × 60

Note: Where Md is taken with unit (N.cm)

The hydraulic input power is calculated from nozzle pressure in Pascal and
volumetric flow rate in m3/sec.

In case of the volumetric flow rate, 100% on the display signifies a volumetric flow
rate 315 l/min or 0.00525 m3/sec

Phydrualic=Nozzle inlet pressure (Pa) *Volume flow rate (m3/s)

The very low outlet pressure can be ignored.

𝑃ℎ𝑦𝑑 = 𝑃𝑑 . 𝑉 (W)

The Efficiency can be calculated from the ratio of mechanical to hydraulic power.

𝑃𝑚𝑒𝑐ℎ
𝜂=
𝑃ℎ𝑦𝑑

Thermodynamics-II Page 66 of 72
Plot a graph between inlet pressure and turbine efficiency.

CONCLUSION:

_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

Thermodynamics-II Page 67 of 72
Post Lab Activity:

1. Define pressure compounding in turbines?

_____________________________________________________________________
_____________________________________________________________________
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2. Define velocity compounding in turbines?

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Thermodynamics-II Page 68 of 72
 LAB SESSION NO. 14

OBJECTIVE

To investigate effect of number of nozzles on the hydraulic power, mechanical power

and impulse turbine efficiency.

EQUIPMENT/PARTS REQUIRED:

Impulse turbine demonstration unit

1. Fully open valve for air cooling and adjust nozzle pressure to 1.5 bar
2. Only open one nozzle.
3. Using the loading device, brake the turbine to a speed of 16500 rpm. Note
torque, nozzle pressure and air volumetric flow rate.
4. Switch in the further nozzles in stages and each time brake turbine using braking
device to 16500 RPM. During this process, ensure that nozzle pressure remains
constant.

Fig. 14.1 (Impulse turbine demonstration unit)

Thermodynamics-II Page 69 of 72
OBSERVATION TABLE:

Number of Moment Power Power Volumetric Efficiency 𝜂

nozzles 𝑴𝒅 in 𝑷𝒎𝒆𝒄𝒉 in Hydraulic, flow in %
N.cm Watt Phyd Watt Rate in %

The mechanical Power is calculated from Torque in N.cm and speed in rpm.

Pmechanical=Torque*angular speed

𝑀𝑑 × 2 × 𝑛 × 𝜋
𝑃∗𝑚𝑒𝑐ℎ = (𝑊)
100 × 60

Note: Where Md is taken with unit (N.cm)

The hydraulic input power is calculated from nozzle pressure in Pascal and
volumetric flow rate in m3/sec.

In case of the volumetric flow rate, 100% on the display signifies a volumetric
flow rate 315 l/min or 0.00525 m3/sec

Phydrualic=Nozzle inlet pressure (Pa) *Volume flow rate (m3/s)

The very low outlet pressure can be ignored.

𝑃ℎ𝑦𝑑 = 𝑃𝑑 . 𝑉 (W)

The Efficiency can be calculated from the ratio of mechanical to hydraulic power.

𝑃𝑚𝑒𝑐ℎ
𝜂=
𝑃ℎ𝑦𝑑

Thermodynamics-II Page 70 of 72
Plot a graph between no. Of nozzles and turbine efficiency

CONCLUSION:

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Thermodynamics-II Page 71 of 72
Post Lab Activity:

1. What are the advantages of impulse turbine?

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2. What are the advantages of reaction turbine?

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Thermodynamics-II Page 72 of 72