I did my internship at Egbin Power plc which is a thermal generating plant, I also learnt Matlab during my internship.
Egbin Power Plc is the largest thermal power generating station in Nigeria with an installed capacity of
1,320MW consisting of 6 Units of 220MW steam turbines. The station is located at Ijede/Egbin, in
Ikorodu. It is about 40 km north east of the city of Lagos, and is situated on low land in Ijede and
bounded by the Lagoon to the south, Agura/Gberigbe to the north and situated in Ijede Local Council
Development Area.The Egbin Thermal Power Plant is a gas-fired plant with each of the six 220MW independent steam
turbine units the boiler (steam generator) is Babcock-Hitachi product and is a dual fired type that can
be run on Heavy Pour Fuel (HPFO) or Natural Gas. The major equipment parts of Egbin power plant
are the boiler, turbine and the generator. Other parts include the condenser, condensate extraction
pumps (CBP), condensate booster pumps(CBP), steam jet air ejectors, gland steam condensers, low
pressure feed water heaters 1-3, Deaerator, high pressure feedwater heaters 5 & 6, boiler feed pumps,
economizer, water treatment plant and demineralization plant.
Each unit comprises a steam generator with reheat and superheat cycles, an extraction steam turbine
with automatic run-up and supervisory system and a hydrogen cooled generator with auto
synchronization and voltage regulation. Combustion air is provided by two 50% duty forced draft fans (F.D.) and the feed water cycle comprises a steam surface condenser with air ejectors, tube cleaning
equipment, two condensate extraction pumps, three 50% duty electric boiler feed pumps and feed
heating trains of three L. P. heaters, Deaerator and two H. P. heaters.
Fuel is supplied to the units from common handling systems. Fuel oil is stored in four main storage
tanks and distributed to the unit via six intermediate storage day tanks. Natural gas is provided via a
high-pressure gas line and is pressure reduced before distribution to the units. The units are capable of
full load operation on both natural gas and fuel oil. Natural gas is used for burner start-up and liquefied
petroleum gas is available from storage to permit operation with oil if natural gas is unavailable for
burner start-up.
1. 1
CONFIDENTIAL AND PROPRIETARY
Any use of this material without specific permission of Egbin Power Plc is strictly prohibited
Tuesday, June 7, 2022
Onalaja Oloruntimilehin
Internship Experience
at eGBIN Power Station
2. 2
About me.
My Name is ONALAJA OLORUNTIMILEHIN
OGOOLUWA, A student of Olabisi
Onabanjo University, Ibogun,
studying Electrical/Electronics
Engineering.
3. 3
Content
• About Egbin Power Plant
• Egbin power generation process
• Department Visited & Lesson learnt
• Conclusion.
4. 4
• largest thermal power generating station
in Nigeria and Sub Saharan Africa and
uses steam turbine to generate
electricity.
• It is located in the city of Lagos, and is
situated on low land in Ijede and started
1985.
• The company contributes over 16% of
the total electricity generated to the
Nigerian National Grid.
• It has provision of one gas turbine
(24MW) and one emergency diesel
generator (1.5MW) for black start.
Egbin Power Plc
EGBIN THERMAL POWER PLANT
5. 5
PROCESS OF HOW COMPANY GENERATE
INCOME
02 03 04
01 05
GENERATION
It produces 16KV
which is then stepped
up to 330KV.
DISTRIBUTION
Electricity is carried
from the transmission
system (33/11 KV).
MONITIZATION
The electricity is connected to the
end user meter and the user pays
for electricity being used which
generate money to the company.
END USER
Commercial, industrial and
residential customers are
connected to the secondary
distribution lines through
service drops (415V,240V).
TRANSMISSION
It transmit 330KV distance to a
sub station (330/132KV or
33KV). Egbin power plant uses
Transmisson Company of Nigeria
(TCN).
6. 6
• Egbin Power station is a 1320MW
capacity steam turbine station
comprising of 6 steam turbine units and
generator each of 220MW installed
capacity.
• The steam turbine is housed in a single
support structure and enclosure.
• The units are capable of full load
operation on both natural gas and heavy
pour fuel oil (HPFO).
• The power plant is a combination of
systems and subsystems which are
composed of many
equipment/components for the
generation of Power.
7. 7
PLANT OPERATION OVERVIEW
The key elements of
electricity generation are:
• Relative Motion
• Electric Field
• Conductor
The generation process in Egbin Power Plc
spans across the following stages:
• Water Production and Treatment Process
• Demineralization Process
• Steam Generation Process (Boiler)
• Steam Work Process (Turbine & Generator)
STAGES IN ELECTRICITY GENERATION
8. 8
Chemical Energy • From Nigeria Gas
Company
Heat
Energy
• By combustion in the Boiler Furnace
Mechanical
Energy • By the Turbine
Electrical
Energy
• By the Generator
PROCESS OF HOW ELECTRICITY IS GENERATED
15. 15
STEAM TURBINE
A prime mover is an engine that converts fuel to useful
work.
A steam turbine is a mechanical device that extracts
thermal energy from pressurized steam, converts it into a
rotary motion.
The energy is transferred from the boiler to the turbine
through high pressure steam that in turn powers the turbine
and generator.
Initial Steam Pressure: 12.5MPa
16. 16
GENERATOR
This is an electro-mechanical device which
converts mechanical energy into electrical
energy. The Synchronous generator consists of
static stator (Armature windings) and a rotating
rotor (field windings).
The rotor of the generator is directly coupled
with the shaft of the turbine so they both turn at
3000rpm
17. 17
EXCITATION
The generator employs single excitation. This means the field windings are energized by DC
supply mainly 440V gotten from the operation of the thyristor stacks and Silicon Controlled
Rectifier (SCR) and 110V from battery bank for field flashing.
18. 18
SYNCHRONIZATION
Five conditions must be met for two generators to be
synchronized :-
1. The number of phases must be the same.
2.The direction of rotation must be the same.
4.The frequencies must be closely matched.
3.The voltage amplitudes must be closely matched.
5.The phase angle’s must be closely matched.
21. 21
21
Health, Safety and Environment.
• The safety of human lives and the
surrounding is taken very
seriously in Egbin, so HSE was
the very first section I went
through.
• There I learnt some basic things as
regarding;
Personal Protective Equipments
Toolbox form
Work permit
22. 22
22
MECHANICAL DEPARTMENT
OIL PURIFIER AND OIL VACUUM PUMP
Figure 46. Oil Purifier.
For this Job, we did a routine
check and maintenance on oil
purifier and vacuum pump by
checking their motors and
investigation of fault and
abnormality. Also, checking of the
oil and refilling of the oil.
23. 23
23
I AND C
REPLACEMENT OF PNEUMATIC
ACTUATOR GAS VALVE
I worked with the instrumentation and control
engineer team to replace a pneumatic actuator 5-
FCV-105, we replaced the gas valve and installed
its auxiliaries (positioner, air filter, booster relay,
air regulator and lock up valve).
I was given the opportunity to calibrate it using a
mA calibrator of 4 – 20 MA.
24. 24
24
SUPER HEATER SPRAY CONTROL VALVE
I worked with the instrumentation and
control engineer team in the inspection
and maintenance on the super heater
spray control valve, replacement of is air
filter and calibration of its positioner using
4 – 20mA calibrator.
25. 25
25
REPLACEMENT OF EP TRANSDUCER
I worked with the instrumentation and
control engineer team to inspect and
replace the electropneumatic transducer
for the boiler feed pump which pumps
water to the boiler and also calibration
of the transducer using 4mA – 20mA
calibrator for Boiler Feed Pump.
26. 26
26
I worked with the instrumentation and
control engineer team on the service air
pressure low alarm for autostart
pressure switch and calibrated it using
oil pressure pump for PSH-2338 for
unit 1 during inspection.
SERVICE OF AIR PRESSURE ALARM
27. 27
27
Reheat spray control valve is an
important accessory in Egbin Power
Plc which help to regulate the
temperature of the reheater.
The reheat spray flow control valve
had a ruptured diaphragm.
A new control valve had to be
installed.
OLD FLOW CONTROL VALVE NEW FLOW CONTROL VALVE
REPLACEMENT OF REHEAT SPRAY CONTROL VALVE
28. 28
28
ELECTRICAL DEPARTMENT
In Egbin, there are 72 carbon brushes
being used.
The Carbon brush maintenance is
carried out daily and during the
routine check.
The length and temperature of the
carbon brushes are recorded, as well
as the temperature of the slip-rings.
29. 29
FILTERATION BREAKER
REPLACEMENT
For this job, I joined the engineer to
work on the oil filtration breaker
replacement which is 3 phase, 415V
and 250A. The oil filtration breaker is
used for filtering the transformer oil.
30. 30
11KV SUBSTATION ALKALINE BATTERY
For this job, we did a routine check on 11kV
substation alkaline batteries and I refilled it with
distilled water. This batteries are used to open or
close 11kVcircuit breakers for housing colony,
watering well, black-start transformer, and gas
turbine generator.
31. 31
TRANSFORMER AND GANTRY TEMPERATURE CHECK
I did routine checks with the electrical
engineers on six generator transformer
16/330kV, six unit service transformer
16/6.6kV, three station transformer
132/11kV and 33/11kV, one black-start
transformer 11/6.6kV.
Thermal Imaging Camera.
32. 32
TRANSFORMER MAINTENANCE
I did maintenance with the electrical
engineer team on 11/415kV
transformer. There was oil leakage in
the transformer.
33. 33
HYDROGEN PLANT ROUTINE
For this job, we did routine check on hydrogen
plant rectifier and electrolyzers. The rectifier
converts alternating currents (A.C) to direct
current (D.C). In this routine check I took the
bearing temperature of the compressor motor
condensate, tank motor and lye recirculation
pump.
Checking the compressor motor temperature in hydrogen plant.
34. 34
UPS ROUTINE FOR 110V AND 240V BATTERY
For this job, we check the batteries, battery current, battery
fault, the battery charger (Input voltage, input current, output
voltage, output current, fuse blowout, charger high voltage,
charger low voltage, AC source, float, equalizer, AC failure and
circuit breaker trip) for both 110V and 240V batteries for each
unit.
36. 36
Simulink is a MATLAB-based graphical programming environment for modeling, simulating and
analyzing multidomain dynamical systems. Its primary interface is a graphical block diagramming
tool and a customizable set of block libraries. It offers tight integration with the rest of the
MATLAB environment and can either drive MATLAB or be scripted from it. Simulink is widely
used in automatic control and digital signal processing for multidomain simulation and model-based
design.
MATLAB SIMULINK
37. 37
MATLAB SIMULINK
Simulated a control system Focus and PID on MTLAB Simulink (parameter used includes: step,
transfer function, sum, integrator, gain, saturation, mux, and scope).
38. 38
Simulated on a system using multiport switch with 3 data port to generate a signal
(Parameter used includes: constant, sine wave, switch, mux and scope).
40. 40
CONCLUSION
Egbin has an installed capacity of 1320MW shared among 6 units each producing 220MW.
And on a daily we work towards achieving maximum capacity by carrying out preventive
and corrective maintenance.
FLUE GAS, WATER IN TUBE BOILER. IGNITER, BURNER, AUXILIARY STEAM, STACK,
Type: TFLQQ – KD Hydrogen Cooled , Rated Capacity: 220MW , Power factor: 0.9, Rated voltage: 16kV, Coolant: Hydrogen, Pole: 2, Frequency: 50HZ
The generator’s rotor and stator are hydrogen cooled and sealed with oil to avoid leakage.
Exciting current is supplied to the field winding through the collector rings. The main brush conducts current from the moving slip rings of the generator to the output lines.
The number of phases in the generator must equal the number of phases of the bus it is synchronizing to.
•This should only be a consideration when initially installing a generator.
The electrical rotationof the generatorbeing brought on line must match the electrical rotation of the busit is synchronizing to.
Voltage amplitudes of the unit coming on line should be slightly higherthan the bus voltage so that the unit will be feeding out power when it ties on.
The frequenciesof the on coming unit and bus must be matched. In some cases, the on-coming unit may have a slightly fasterfrequency in order for the oncoming generator to immediately start producing power.
The phase angleof the generator and bus must be matched.
Zero hare, Sustainability, Sustainability, Zero harm
I Pledge to ensure the safety of everyone and the protection of our environment at all time.
These brushes are divided into two for the two slip rings in each; 36 brushes for the positive side, while the other 36 brushes are for the negative side of the unit generator exciter cubicle.
The Carbon brush maintenance is carried out daily and during the routine, the length and temperature of the carbon brushes are recorded, as well as the temperature of the slip-rings. The carbon brush wears at about 10-15mm per 1000hr at a current density of 6-8A/cm2. When the length of the carbon brush is below 54mm, a new carbon brush is set to replace it. The maintenance is carried out by a team of at least 3 people. The first person is designed to pull out the brushes and also return them after being cleaned and also recorded. The second person ensures that the brushes are cleaned with a clean cloth. The third
person is in charge of the temperature measurement and also, the lengths of the brushes.
BRUSH
BRUSH HOLDER
We also used service air to clean the compartment of the carbon brush in the excitation cubicle.
The instruments and materials necessary for this maintenance includes: Fluke IR thermometer (measures temperature of carbon), Vernier Calliper (measures the length of the carbon), Screwdriver (for replacement of short carbon), Clean clothes (for cleaning of soot deposited on the carbon brush), nose mask (protection from the inhaling of soot particles), hand gloves (the carbon brushes are usually hot), eye google.
The Transformer oil is an essential part of the high-power transformer because it serves as a means of insulation to the coil and also to prevent explosion from occurring inside the transformer.
We checked for the transformer bushing for the red, yellow and blue phase, the tank temperature (up and down), the transformer load, check the colour of silica gel in the breather, oil level, oil temperature, winding temperature, the cooling fans working conditions, abnormal noise, vibrations, and gantry check using the thermal imaging camera, also did gantry check on transmission line.
Before we could work on the transformer we have to open the circuit breaker and isolate the transformer from the sub station. We also off the Ring Main Unit (RMU) of the transformer for safety purpose. We used our protective equipment and started working on the transformer, we drained the oil from the transformer tank and tightened the tank bolt, we also replaced the bushing gasket and tightened the bushing for the 3 phase (red, yellow, and green phase).
The electrolyzer is a system that uses electricity to break water into hydrogen and oxygen in a process called electrolysis. Through electrolysis, the electrolyzer system creates hydrogen gas. The entire system also contains pumps, vents, storage tanks, a power supply, separator and other component.
For the AVR panel (25KVA) we check the AC input voltage, AC output voltage nd AC output current.
For the AVR panel (25kVA) we checked the AC output voltage and AC output current. The line regulator checks includes input voltage, input current, AC source and line regulation operation. We also check the battery current.
We also check for static switch output voltage, output current, output frequency if we are using the battery for field flashing for excitation and the 240V in powering some motors.
