Internship report was made after doing 5 weeks Internship at Sapphire Power Plant (GE). It included all the main features of Power Plant.

1. SAPPHIRE POWER PLANT
Internship Report
234 MW MURIDKE CCPP SAPPHIRE ELECTRIC COMPANY
SUBMITTED TO: -
ZIA-UL-ISLAM
(HR Manager)
SUBMITTED BY: -
MUHAMMAD USMAN
PH # 0335-4770766
Email ID, muhammadusmankambo@gmail.com
MECAHNICAL ENGINEER
UNIVERSITY OF ENGINEERING &TECHNOLOGY, LAHORE

2. Acknowledgement
First of all I’m very grateful to Allah Almighty who has blessed me for everything. With His great
blessings, I am to complete my 5 Weeks span at Sapphire Power Plant.
After that, I pay tribute to all the Managers, Senior Engineers and all the supervisors who helped
me in raising my knowledge, both theoretically and practically. Great thanks to sir ZIA-UL-
ISLAM for providing me the opportunity for the internship at the power plant. Sir Saleem (FM)
and Sir Ayub (MM) have effectively guided me during the Internship period. Their support, in
how to tackle the things, has helped me a lot during my stay. Moreover, Sir Azhar (Mechanical
Engineer) and Sir Waheed, guided me a lot in grasping my field knowledge both practically and
theoretically.
And finally, I pay compliment to my parents who are always there to support me and guide me in
a proper direction. Thank you so much.

3. ABOUT THE AUTHOR
My name is Muhammad Usman. I belong to a city of Punjab, Pakistan. I have a strong education
background from both aspects i.e. Theoretical and Practical. I am a student of BSc. Mechanical Engineering
of 2015 session from the University of Engineering & Technology, Lahore. I Did Fsc in 2015 by a securing
remarkable distinction from Punjab College (KOT ADDU). In 2013, I completed my Matric by achieving
a high percentage from The City School (KAPCO Chapter). All this added to enhance my knowledge about
the field.
Before the Internship at SAPPHIRE Power Plant, I also did an Internship at Pakistan Railways thus gaining
much a knowledge about Locomotives. I have also attended workshops i.e. Attended three days’ workshop
at NIDA (National Institute of Design Analysis) at Lahore thus procuring sound understandings about the
Design of Heat Exchangers and much more.
I have also done many projects in the university and also written their reports.

4. Table of Contents
Abstract .........................................................................................................................................................6
1. Introduction...........................................................................................................................................6
2. EHS (Environment, Health and Safety) ................................................................................................7
2.1 Safety Induction & Overview about major Procedures.................................................................7
2.2 Initial EHS Trainings and Overview about risk assessment .........................................................7
2.3 EHS Walk and Site visit & Hazard Hunt ......................................................................................7
2.4 Execution Training........................................................................................................................8
3. Chemical ...............................................................................................................................................8
3.1 Lab Visit........................................................................................................................................9
4. Operations & Performance....................................................................................................................9
4.1 General tour the Power Plant ........................................................................................................9
4.2 Process of CCGT...........................................................................................................................9
4.3 Lube Oil System..........................................................................................................................11
4.4 Cooling System ...........................................................................................................................11
4.5 Heat Recovery Steam Generator.................................................................................................11
4.5.1 Parts.....................................................................................................................................12
4.5.2 Operational Detail ...............................................................................................................12
4.5.3 Technical Parameter............................................................................................................13
5. Electrical Department..........................................................................................................................13
6. Mechanical Department ......................................................................................................................14
6.1 Measuring Instruments................................................................................................................14
6.2 Mechanical Tools........................................................................................................................14

5. Table of Figures
Figure 1 Water Treatment Plant....................................................................................................................8
Figure 2 Gas Turbine following the Brayton Cycle....................................................................................10
Figure 3 The T-S and P-V diagram for ST..................................................................................................10
Figure 4 CCPT ............................................................................................................................................11
Figure 5 Layout of HRSG and Flow diagram.............................................................................................13

6. Abstract
The main purpose of the internship at the Sapphire Power Plant was to gain the practical knowledge about
the field. All the theoretical study, gained by the three years of study, at the university was examined
practically. The systems were overviewed and studied thoroughly. All the sites were visited that made our
concepts clear (regarding the organization) how it actually worked. There were four major departments i.e.
EHS & Chemicals, Operations & Performance, Electrical and I &C’s and Mechanical and S&P for different
time periods.
1. Introduction
SAPPHIIRE POWER PLANT Muridke is a GE combined cycle power plant having a gross Power output
as 234MW. It is situated 10KM on Sheikhupura-Muridke road. A highly developed company with 2 Gas
Turbines (GT’s) named GE6FA and 1 Steam Turbine (ST) of nearly 75MW and 79MW respectively.
During the internship span of I month, 4 major departments were covered. Firstly, EHS & Chemical
departments were covered for a period of 4 days, where different topics were covered related to the
properties of Environment, Health and Safety and chemistry of Chemicals. Here, all the safety precautions
along with their essential trainings were covered. And the characteristics of water along with its treatment
procedures and testing were thoroughly overviewed and visited. Secondly, department of Operations &
Performance was visited for a period of 4 days. In this span, certain topics were covered related to Steam
Turbine and Gas Turbines. All the system related to operations were viewed and toured practically.
Furthermore, the Cooling System, Fuel System, Feed Water System and Electrical System was studied in
depth. Both theoretical along with the Practical Knowledge was gained from the advisor. Manuals were
studied. The PID’s and notes were understood by one of the Supervisors and further, their sites were visited.
Thirdly, Electrical and I&C department was visited. Here, electrical system was learned. The working
principle and structure of Generators and Transformers were learned along with the diagram of Switch
Yards. Different types of Breakers were studied.
Here is a brief overview of the Power Plant features as mentioned below: -
Company Sapphire Electric Company Ltd
Plant Name Muridke 234MW CCPP
Location Muridke, District Sheikhupura, Punjab
Fuel Duel Fuel (LFO/Gas)
Technology Combine Cycle
Plant Configuration 2 GT‘s (GE) , 2 HRSG and 1 ST
Control System DCS (PCS-7) Siemens
Gas Fuel Supplier SNGPL
Power Consumers NTDC
Commissioning Date 04.10.2010
Connected grids 132 kV ICI Grid, Aisha textile Grid,
Sheikhupura industrial-I and Sheikhupura industrial-II

7. 2. EHS (Environment, Health and Safety)
The internship at Environment, Health and Safety department was of three days. The main features of this
internship are as listed down: -
 Safety Induction
 Overview of Major Safety Procedures
 EHS walk and Site visit
 Hazard Hunt
 Understanding of Gensuit system
 Initial EHS trainings
 Overview about area risk assessment
2.1 Safety Induction & Overview about major Procedures
First of all we were inducted by EHS officer. Based upon the test our induction was taken. Further, we were
guided about the precautions and safety measurements in the organization. An introduction to the PP’E
(Personal Protection Equipment) was made. In which the wearing of Helmet, Glasses and Safety Shoes
were compulsory. The PP’E zone and without PP’E zone was familiarized. The Alarms system was briefed
in which 2 types of Alarms rings. First Alarm rings on every Thursday for the testing purpose, which is
continuous. And the second one in case of emergency which rings for an interval of 90 seconds with an
interval of 3 seconds. In this case all the persons have to gather in an Assembly Ground where heads are
counted for every department. Furthermore, an introduction of all the safety procedures were told along
with their Hazards. An emergency number was told in case of any threat.
2.2 Initial EHS Trainings and Overview about risk assessment
We were given many trainings related to the EHS. About 8 to 10 trainings were briefed so that we could
get familiarized with the essential Procedures their hazards and along with their precautions. There were
about 13 recognitions for every type EHS trainings as listed: -
1. Chemicals
2. Confined Space
3. Electrical
4. Emergency Preparedness
5. Equipment and Control
6. Ergonomics
7. Lockout Tag out
8. Machine guarding
9. Fall protection
10. Material Handling
11. Power Press
12. PPE
13. Workplace conditions and cleanliness
2.3 EHS Walk and Site visit & Hazard Hunt
Sites were visited with the EHS officer where all sort of Hazards were analysed. Mainly the WTP was
visited. Here these things were checked out as: -
 All Fire Extinguishers
 PPE’s check out
 Panel Locks
 Sample Basin
 Basement (Smoke Detectors)
 Emergency Shower check out
 Chemical Storage Area check out
 Drums and earth wiring

8. 2.4 Execution Training
A meeting was held by the EHS officer with all the working staff of Electrical, Mechanical & Operations
about the Execution. Firstly, the presences of Hazards during the execution and the criteria for finding them
was discussed. Secondly, the controlling mechanisms and the requirement of Permit was briefed.
3. Chemical
We spent 2 days in the chemical department where Chemical Department Officer briefed about the chemical
systems in the Power Plant. The main objectives are as listed: -
 Learning about characteristics of water
 Overview of RP system
 Learning about raw water source and its physical treatment
 Learning about boiler water chemistry
 Learning about all major sampling and testing techniques
 Water Treatment Process
Main two questions rises in mind that,
1. What is source of Water and what are the Impurities in Water?
2. Why there is a need to refine the water and how are they eliminated?
The source of water of Sapphire Power Plant is the underground water. Water is pumped by 6 Submersible
Pumps which is then stored in large tanks. This water has two types of impurities i.e. TDS and TSS (Total
Dissolved Substances i.e. Calcium, Magnesium, organic and many more ionic substances and Total
Suspended Substances i.e. sand, wastes etc.). For removing these impurities water is treated. Water from
the Tanks is pumped to Water Treatment Plant, for cleaning the water. WTP includes 6 Sand Filters where
blower is used for removing the fumes and then water is filtered. Further it is supplied where required. The
RO (Reverse Osmosis) plant is installed for further cleaning up the water i.e. demineralizing the water. The
water is sent from the mixed bed (resign) to the membrane and then the permeate storage tank and lastly to
the demineralized water tank. Firstly, it has conductivity of 600 Siemens per meter and at last it has just 0.2
Siemens per meter. From there it is supplied to its 2 main users
 Power Generation
 Cooling System units
Figure 1 Water Treatment Plant

9. 3.1 Lab Visit
In the chemistry lab there were many tests apparatuses which were used for the lab testing of water
characteristics. Here is a list of some main test applauses: -
 pH meter
 Conductivity meter
 Oil tester
 DR 2800 spectre-meter + DR 6000
 Chemicals
 TDS water Tester
4. Operations & Performance
The main objective of this department are listed below: -
 General tour of the site to see locations of various plant equipment
 Understanding on process of CCGT
 Steam Turbine and Steam system overview
 Liquid Fuel system overview
 Electrical system overview
 Condensate system overview
 Feed system overview
 Cooling system overview
 Auxiliary system overview
 Overview of Commercial Obligations (PPA)
4.1 General tour the Power Plant
Firstly, we made a tour to the whole Power Plant with our supervisor who briefed us about the whole system
of Power Plant. He showed us various working system in the plant. We visited the Gas Turbine where its
whole system was viewed and studied, the steam turbine parts, cooling towers, feed water system and
electrical system. Our supervisor briefed us about the working principles and different parts of the system
of the whole plant.
4.2 Process of CCGT
In order to understand the process of combined cycle gas turbine, we have to make our understanding strong
regarding the GT’s and ST’s and their working principles.
The GT (Gas Turbine) work on the principle of Brayton Cycle. First, the air is feed from the inlet where it
is sent to the compressor. The compressor has about 17 stages where the air is highly compressed. The
Pressure of the air is raised to a very high value along with a bit rise of Temperature. The pressurised air is
sent to the combustion chamber. In the Combustion Chamber the Pressurised air is mixed with the fuel i.e.
LNG (Liquefied Natural Gas) and is ignited by the spark plug. The burning takes place and temperature is
raised to a high value. This high pressurised and high temperature air is sent to the Turbine where the air
passes through the 3 stages having rotors and stationary blades and is expanded due to which it transfers its
energy to the blades of the turbine. The shaft of the turbine is coupled with the shaft of the generator which
moves with in the magnetic field. There is three phase windings. This produces a flux and due to which
electricity is generated and is sent forward.
And here, is the PV pressure volume diagram of the Brayton Cycle.

10. Figure 2 Gas Turbine following the Brayton Cycle
Now the air which comes out of the Turbine is of high temperature i.e. about 550o
C. This cannot be wasted
in the atmosphere. So this high temperature is now utilised in the Steam Turbine for an increase of
efficiency.
The ST (Steam Turbine) works on the principle of Rankine Cycle. Here first the water is heated so that it
is converted into steam. For this purpose the high temperature air is used to boil the water in the boiler. The
process is Isobaric Heat Addition. The steam is then expanded in the Turbine in order to extract power from
the high pressurised, high temperature steam. This is an Isentropic Expansion as the entropy of the system
remains same. Now, due to expansion i.e. Joule Thomson Effect, sudden expansion produces cooling effect.
Hence, the temperature of the Steam is decreased. The shaft of the Turbine is connected with the Generator
shaft due to which electricity is generated. Further, the steam is condensed back into water and the process
s called Isobaric Expansion for the process takes place at same pressure. There are cooling Towers where
the Temperature of steam is decreased to normal temperature. This water is then pumped back into the
boiler. The feed pump increases the pressure of the condensate and the process is called Isentropic
Compression as the process takes places with the same entropy. The condensate is again sent into the boiler
for again use.
The TS and PV diagrams are listed as below: -
Figure 3 The T-S and P-V diagram for ST
The diagram of combine cycle power plant is shown as below: -

11. Figure 4 CCPT
4.3 Lube Oil System
The lubrication system for the gas turbine, the load gear and the generator are incorporated in a common
system. It includes the lubricating oil system module, interconnecting piping and components supplied with
lubricant in other modules.
First there is a Lubricating Oil Reservoir Tank where oil is stored. Further, there are AC Pumps which
pump the lube oil to the suppliers.
4.4 Cooling System
Cooling System are of two types i.e. Auxiliary Cooling Water System and Cooling Water System. The
suppliers of ACWS are as given below: -
Steam Turbine
 Alternator
 Lubrication Oil
 Hydraulic Fluid
 HP Feed Water Pump 1
 HP Feed Water Pump 2
 HP Feed Water Pump 3
 Instrument Air Compressor
Gas Turbine
 Spray System
 Alternator
 Lubrication
 Flame Detector
4.5 Heat Recovery Steam Generator
The HRSG (Heat Recovery Steam Generator) is system for generating Steam which is suitable for the
Turbine in order to run the ST for the Power Generation purpose. Every HRSG has its own specifications
as per requirements.

12. Followings are the specification of HRSG used in this Power Plant are as follows: -
HRSG Design Horizontal type
Steam System HP and LP
Water circulation Natural
Tubes Arrangement Vertical Type Bundles
Flow arrangement Water tube
4.5.1 Parts
The parts of HRSG which are very necessary for the working of an efficient heat recovery steam generator
are as follows,
 Economizers
 Evaporators
 Super Heaters
 DE Super Heaters
 HP & LP Drums
 Feed water pumps
 Deaerator
 Heat Exchangers
 Injectors
 Air Pre Heaters
4.5.2 Operational Detail
The complete cycle of HRSG system includes the Feed Water system and Condensate System. Following
is the description of the complete cycle.
The exhaust gases from the Turbine of GT are horizontally oriented, tempered of 520o
C. Their energy is
utilized to boil up the water coming from the Feed Water Tank and convert it into steam for running the
Steam Turbine.
The Condensates Pumps, pressurizes the water into the Heat Exchangers where temperature of the water
is raised to some extent and is aerated and then sent into the Feed Water Tank. From there the water is
pumped into Low Pressure and High Pressure Pumps. The LP and HP pumps pressurizes the water into the
Economizers. From there, the water is sent into the LP & HP Feed Water Drums respectively. The
temperature of the water is rising gradually. Then, the water comes down to the Evaporators and again sent
back into the drums. Now, the water is converted into Steam. The steam is collected and is now superheated
using Super Heaters. Here, the steam is heated to high extent. It does not meet the requirement for the
turbine due to its somewhat High Temperature and low Pressure than required. So, some water is added
into the steam for lowering the Temperature to some degrees and raising the Pressure of water to some
Bars. Then the Steam is De superheated using DE Super heaters for avoiding any moisture content in the
Steam. From here the LP and HP Steams are sent into the Turbine for its running. The outgoing steam is
now condensed into the Condensers and is again utilized. The cycle goes on again in a similar way.
Here is the flow diagram of HRSG system from the Condensers to the Steam Turbine (ST). The flow
diagrams includes all the essential parts of Power plant i.e. ST, GT exhaust, Feed Tank, Aerator, the
Pipelines, Pumps and the HP & LP drums.

13. HP Drum
LP Drum
Steam
Turbine
Condensers
Cond. Pumps
Heat
Exchangers
Feed Water Tank
LP Pumps
HP Pumps
Heat Recovery Steam Generator
Aerator
Figure 5 Layout of HRSG and Flow diagram
4.5.3 Technical Parameter
Nominal flue gas temperature after GT 611˚C
Maximum flue gas temperature after GT 650 ˚C
Nominal flue gas mass flow from GT 200kg/s
Maximum flue gas mass flow from GT 220kg/s
Maximum feed water temperature 140˚C
Nominal outlet steam temperature 538˚C
Maximum outlet steam flow 31.3kg/s
Nominal outlet steam pressure 93bar
Nominal outlet steam temperature 270˚C
Maximum outlet steam flow 6.3kg/s
Nominal outlet steam pressure 4.8bar
5. Electrical Department
In Electrical Department I got somewhat knowledge about the electrical field. The working principles of
Generators, Transformers etc. were thoroughly studied. Their types and applications were briefly discussed.
The Switch Yard system was understood.

14. 6. Mechanical Department
In Mechanical Department I learned about the Measuring Instruments and the Techniques of measuring
any particulars. Details about the Mechanical Tools were studied and discussed. The overall system of
ST’s and GT’s was studied in detail.
6.1 Measuring Instruments
Following is the list of Mechanical Measuring Instruments used for measuring Mechanical parts as listed;
 Inside/ Outside Micrometre
 Inside / Outside Vernier
 Bore Gauge
 Depth Gauge
 Telescopic Gauge
 Block Gauge
 Snap Gauge
 Taper Angular Gauge
 Thread Angular Gauge
 Meter Tape
 Steel Rule
 Bevel Protractor
 Temperature Gun
 Vibration Pen
 Dial Gauge with Magnetic Stand
 Wire Gauge
 Height Gauge
 Master Gauge
 Spirit Gauge
 Weight Scale
 Ultrasonic Thickness Meter
 Filler Gauge
Every Measuring Tools has its own specifications and properties. Most of the Instruments may have a same
job of measuring the same dimensions but the difference lies in the accuracy of the measuring device. Each
apparatus has its own Least Count due to the readings get more precise and accurate.
6.2 Mechanical Tools
Mechanical Tool box was visited where many different kinds of Tools were available for many jobs. The
list of the tools is listed as below: -
 Wrench
 Hamer
 Screw Driver
 Spanners
 Saw
 Chisel
 Pliers
 Sockets
 Torque Wrenches
 Pipe Wrenches
 Tube Cutters
 Scrappers
 Files and Rasps
 Brushes
 Knives

15.  Drill Machines
 Drill bits
 Blowers
 Converters
 Power Multipliers
 Ratchets
Also a studied about Pumps and Compressors. Their working principles, types, problems and applications
were analysed and thoroughly studied. The maintenance of GT’s and ST’s along with a complete layout
from the PID’s were discussed with the supervisor. The starting of ST and GT was discussed in detail.