This document provides a summary report of a 15-day summer training program at a Hindustan Zinc Limited Captive Power Plant. It discusses the key components and processes involved in generating electricity from coal at a thermal power plant, including the boiler, turbine, condenser, and feed pump. The report also provides overviews of the coal handling process, basic instrumentation systems, programmable logic controllers, and concludes with references.
Summer Training Report on Electrical Engineering Fundamentals at Thermal Power Plant
1. A
Report on
Summer Training
At
Submitted in partial fulfillment for the award of
Bachelor of Technology
In
Electrical Engineering
SESSION:- 2015 -2016
Submitted to: - submitted by:-
Mr. Piyush Sharma Name: - Lalit Salvi
H.O.D (EEE/EE) Roll No.:- 12ECOEE009
2. CONTENTS
1. Preface
2. Acknowledgement
3. Introduction
4. Overview
5. Electricity from coal
6. Thermal power plant
7. Fundamental parts
8. Basic Instrumentation Systems
9. PLC
10.Conclusion
11.References.
3. PREFACE
This fifteen days training was very educational adventure for me. It was really amazing
to see the plant by myself and learn how electricity, which is one of our daily requirements of life,
is produced. This compiled report gives an insight into the productive and rising sector of the
industry. The Captive Power Plants are constantly proving themselves in the power sector and are
being widely accepted by the industries. The report gives the detailed concept about the working
of the plant systems and various cycles that go on. A brief introduction describes the advantages
and outlines the requirements around which the motive revolves. This report has been made by
self-experience at CPP, HZL.The material in this report has been gathered from my textbooks,
senior student report, and trainer manual provided by training department. The specification &
principles are at learned by me from the employee of each division of CPP. The introduction is
followed by the detailed overview of the power plant, discussing all the major processes that take
place in the procedure of power generation.. Thus, the power plant exhibits expertise in terms of
planning and implementation which proves to
be very valuable if understood deeply. It outlines the whole course of my
training in a specified and oriented manner. The basic aim of this report is to study the
organizational setup of CPP, the division of plant into various blocks, depts., auxiliary units and
laboratories as well as the latest power generation technique employee to produce quality service.
It gives a wholesome picture of how work is carried out at CPP in the different depts. present there
and the overview of the coordinated and well planned, systematic manner in which these depts.
feed each other to meet the power demands efficiently. From the Mechanical point of view the
CPP have so many setups which offers a great opportunities to the budding engineers to nurture
their skills.
4. ACKNOWLEDGEMENT
With profound respect and gratitude, I take the opportunity to convey my thanks to complete the
training here. I do extend my cordial thanks to Mr.P.K.Mandal for providing me this opportunity
to be a part of this esteemed organization. I am extremely grateful to all the technical staff of HZL
and THERMAX for their co-operation and guidance that helped me a lot during the course of
training. I have learnt a lot working under them and I will always be indebted of them for this value
addition in me. The valuable help was the reason because of which this report could be prepared.
I would like to thank Mr.Mangi lal Sharma, Mr. Mayank Varshney, Mr. Manavendra Singh, Mr.
Himanshu Chasta for explaining me the details about the plant and its processes. Finally I could
say I have not only seen the things in plant but also learnt it. And also many things like managing
workmen talking to executives and decision making skills etc. I could definitely be benefited by
this training.
Last but not the least I would like to express my gratitude to the workers, engineers and all
employees who shared their experience with me.
(Lalit Salvi)
5. INDUSTRIAL TRAINEE
Hindustan Zinc Limited is a power intensive industry, the manufacturers of nonferrous metals. The
production technology requires huge amount of uninterrupted power. To compete with worldwide
market and establish itself, the Zafar Captive Power Plant (CPP) has been established along with
CPP in Chanderiya and Debari. Altogether, CPP caters to the requirement of all smelters and Mines
through Open access and Wheeling under Electricity Act 2003. Today, in captive power industry,
45% of the power is steam generated, 40% of power is generated by diesel or similar fuel and 15%
of the n, there is also growing awareness among all concerned to keep the pollution under control
and preserve the health and quality of the natural environment in the vicinity of the power stations.
HZL is committed to provide affordable and sustainable power in increasingly larger quantity.
HZL is conscious of its role in the national endeavour of mitigating energy poverty, heralding
economic prosperity and thereby contributing towards India’s emergence as a major global
economy. The Zawar Captive Power Plant (CPP) has been established in December 2008.
Captive Power Plant is a generating unit(s) which produces power for captive consumption
(minimum 51%) of its owners.
6. INTRODUCTION
LOCATION
Hindustan Zinc Ltd.1x80 MW Captive Power Plant is a certified unit of ISO, Quality
management system, Environmental management system (9001, 14001), and Occupational, health
and safety (OHSAS: 18001). It is the only integrated Zinc-Lead producer in India & aims at
becoming global leader in Zinc production. Also it has proven track record from last 40 years in
mining & smelting. And recently it has planted captive power plant units in Zawar Mines,
Chanderia and Dariba Mines etc. It is located 44kms South of Udaipur in the state of Rajasthan,
India.
power is generated by natural gas/naphtha. Higher efficiency Combined Cycle Gas Power Plants
are already under operation at all gas-based power projects. Advanced clean coal technologies
such as Integrated Gasification Combine d Cycle (IGCC) have higher efficiencies of the order of
7. 45% as compared to about 38% for conventional plants. With the massive expansion of power
generation,
CPP (ZAWAR MINES)
CPP is efficiency oriented eco-friendly and eco-nurturing initiative towards environmental
protection and continued commitment to sustainable power development in India.
Distribution of Power
8. OVERVIEW
(1X80 MW unit)
BOILER THERMAL
STATION CAPACITY 100% coal OR 100% diesel
FUEL-COAL-SOURCE Imported coal from South Africa
and Indonesia. Indian coal from
Navlakhi and Mundra Port.
TRANSPORTATION By truck
CONSUMPTION 7680 TPD
COOLING WATER SOURCE Tidi dam
9. REQUIREMENT 5000m3
START UP POWER 16.5MVA@ 132 KV through
RVPNL
ASH DISPOSAL Dry ash disposal system
CHIMENY RCC multiflue chimney
With steel flue 175m high
HEAT RATE 2670 Kcal/KWh
HP/LP BYPASS CAPACI 60% of MCR
ELECTRICITY FROM COAL
Coal from the trucks is unloaded in the C.H.P. This coal is taken to the raw coal bunkers
with the help of conveyor belts.
10. Coal is then transported to bowl mills by coal feeders where it is pulverized and ground in the
powdered form. This crushed coal is taken away to the Furnace through coal pipes with the help
of hot and cold mixture P.A fan. This fan takes atmospheric air, a part of which is sent to pre
heaters while a part goes to the mill for temperature control. Atmospheric air from F.D fan in the
air heaters and sent to the furnace as combustion air. Water from BFP (boiler feed pump) passes
through economizer and reaches to the boiler drum. Water from the drum passes through the down
comers and goes to the bottom ring header.
Water from the bottom ring header is divided to all the four sides of the furnace.
Due to heat density difference the water rises up in the water wall tubes. This steam and water
mixture is again taken to the boiler drum where the steam is sent to super heaters for super heating.
The super heaters are located inside the furnace and the steam is super heated (540 degree Celsius)
and finally it goes to the turbine. Flue gases from the furnace are extracted from the induced draft
fan, which maintains balance draft in the furnace with F.D fan. These flue gases heat energy to the
various super heaters and finally through air pre heaters and goes to electrostatic precipitators
11. where the ash particles are extracted. This ash is mixed with the water to form slurry is pumped to
ash period. The steam from boiler is conveyed to turbine through the steam pipes and through stop
valve and control valve that automatically regulate the supply of steam to the turbine. Stop valves
and controls valves are located in steam chest and governor driven from main turbine shaft operates
the control valves the amount used. Steam from controlled valves enter high pressure cylinder of
turbines, where it passes through the ring of blades fixed to the cylinder wall. These act as nozzles
and direct the steam into a second ring of moving blades mounted on the disc secured in the turbine
shaft. The second ring turns the shaft as a result of force of steam. The stationary and moving
blades together. And hence the generator produces electrical output, which is then sent to the
switch yard. Produced 11KVis step up by generator transformer to 132KV and sent to RSEB. And
produced electricity is also utilized for plant running purposes by stepping down to 6.6KV and/or
415KV by unit auxiliary transformer. This is the complete story of how black coal is converted
into luminous electricity.
12. THERMAL POWER PLANT
A Thermal Power Station comprises all of the equipment and a subsystem
Required to produce electricity by using a steam generating boiler fired with fossil fuels or bio
fuels to drive an electrical generator. Some prefer to use the term ENERGY CENTER because
such facilities convert forms of energy, like nuclear energy, gravitational potential energy or heat
energy (derived from the combustion of fuel) into electrical energy. However, POWER PLANT
is the most common term in the United States; While POWER STATION prevails in many
Commonwealth countries and especially in the United Kingdom. Such power stations are most
usually constructed on a very large scale and designed for continuous operation. Working Layout
of a simplified thermal power plant the plant is based on the Modified Rankine Cycle. The Rankine
cycle is a thermodynamic cycle which converts heat into work. The heat is supplied externally to
a closed loop, which usually uses water as the working fluid. The Rankine cycle is sometimes
referred to as a practical Carnot cycle as, when an efficient turbine is used, the Temperature –
Entropy (TS) diagram will begin to resemble the Carnot cycle. The main difference is that a pump
is used to pressurize liquid instead of gas. This cycle generates about 80% of all electric power
used throughout the world, including virtually all solar thermal, biomass, coal and nuclear power
plants.
13. Rankine cycle
Process 1-2: The working fluid is pumped from low to high pressure. As the fluid is a
Liquid at this stage, the pump requires little input energy.
Process 2-3: The high pressure liquid enters a boiler where it is heated at constant
pressure by an external heat source to become a dry saturated vapour. The
input energy required can be easily calculated using mollier diagram or h-s
chart or enthalpy-entropy chart also known as steam tables.
Process 3-4: The dry saturated vapour expands through a turbine, generating power. This
decreases the temperature and pressure of the vapour, and some
condensation may occur. The output in this process can be easily calculated
using the Enthalpy-entropy chart or the steam tables.Process 4-1: The wet
vapour then enters a condenser where it is condensed at a constant
pressure to become a saturated liquid.
14. In an ideal Rankine cycle the pump and turbine would be isentropic, i.e., the pump and turbine
would generate no entropy and hence maximize the net work output. Processes 1-2 and 3-4
would be represented by vertical lines on the T-S diagram and more closely resemble that of the
Carnot cycle. The Rankine cycle shown here prevents the vapor ending up in the superheat
region after the expansion in the turbine, [1] which reduces the energy removed by the
condensers.
The actual vapor power cycle differs from the ideal Rankine cycle because of irreversibilities in
the inherent components caused by fluid friction and heat loss to the surroundings; fluid friction
causes pressure drops in the boiler, the condenser, and the piping between the components, and
as a result the steam leaves the boiler at a lower pressure; heat loss reduces the net work output,
thus heat addition to the steam in the boiler is required to maintain the same level of net work
output.
Equations
In general, the efficiency of a simple rankine cycle can be written as:
There are mainly three cycles which drives the working of Power plant –
• Steam-Water Cycle
• Air Flue Gas Cycle
• Coal and Ash cycle
For this cycle maintenance there are auxiliary systems which are called is Balance of Plant System,
proper working of each system ensures the efficient working total plant.
15. And those systems as follows-
1. Coal Handling Plant (CHP)
2. Demineralised Water Plant (DMP)
3. Ash Handling System (AHP)
4. Cooling Tower
BASIC OPERATION OF THERMAL POWER PLANT:
A thermal power plant basically works on rankine cycle.
COAL CONVEYOR: This is a belt type of arrangement. With this coal is transported from
coal storage place in power plant to the place near by boiler.
STOKER: The coal which is brought near by boiler has to put in boiler furnace for
combustion. This stoker is a mechanical device for feeding coal to a furnace.
PULVERIZER: The coal is put in the boiler after pulverization. For this pulverizer is used.
A pulverizer is a device for grinding coal for combustion in a furnace in a power plant.
BOILER: Now that pulverized coal is put in boiler furnace. Boiler is an enclosed vessel in
which water is heated and circulated until the water is turned in to steam at the required
pressure.
SUPERHEATER: Most of the modern boilers are having super heater and reheater
arrangement.
REHEATER: Some of the heat of superheated steam is used to rotate the turbine where it
loses some of its energy. Reheated is also steam boiler component in which heat is added
to this intermediate-pressure steam, which has given up some of its energy in expansion
through the high-pressure turbine.
CONDENSER: Steam after rotating steam turbine comes to condenser. Condenser refers
here to the shell and tube heat exchanger (or surface condenser) installed at the outlet of
every steam turbine in thermal power stations of utility companies generally.
COOLING TOWER: The condensate (water) formed in the condense after condensation
is initially at high temperature. This hot water is passed to cooling towers. It is a tower-or
16. building-like device in which atmospheric air (the heat receiver) circulates in direct or
indirect contact with warmer water (the heat source) and the water is thereby cooled (see
illustration).
ECONOMISER: Flue gases coming out of the boiler carry lot of heat. Function of
economizer is to recover some of heat from the heat carried away in the flue gases up the
chimney and utilize for heating the feed water to the boiler. It is placed in passage of flue
gases in between the exit from the boiler and the entry to the chimney.
AIR PREHEATER: The remaining heat of flue gases is utilized by air preheater. It is a
device used in steam boilers to transfer heat from the flue gases to the combustion air before
the air enters the furnace. Also known as air heating system. It is not shown in the layout.
But it is kept at a place near by where the air enters in to the boiler.
ELECTROSTATIC PRECIPITATOR: It is device which removes dust or other finely
divided particles from flue gases by charging the particles inductively with an electric field,
then attracting them to highly charged collector plates. Also known as precipitator.
SMOKE STACK: a chimney is system for venting hot flue gases or smoke from a boiler,
stove, furnace or fireplace to the outside atmosphere. They are typically almost vertical to
ensure that the hot gases flow smoothly, drawing air into the combustion through the
chimney effect (also known as the stack effect).
GENERATOR: an alternator is an electromechanically device that converts mechanical
energy to alternating current electrical energy.
TRANSFORMER: it is a device that transfers electric energy from one alternating-current
circuit to one or more other circuits, either increasing (stepping up) or reducing (stepping
down) the voltage
17. The above diagram helps us to study the operation of a coal based power plant also known as
thermal power plant. The power plant operates on rankine cycle which continuously converts heat
into work, in which a working fluid repeatedly performs a succession of processes.
The thermal power plant is basically based on the "simple rankine cycle".
FUNDAMENTAL PARTS:
Boiler
Steam turbine
Condenser
Feed pump
18. Three phase transmission line
Three phase electric power is a common method of electric power transmission. It is a type of
polyphase system mainly used to power motors and many other devices. A Three phase system
uses less conductor material to transmit electric power than equivalent single phase, two phase, or
direct current system at the same voltage. In a three phase system, three circuits reach their
instantaneous peak values at different times. Taking one conductor as the reference, the other two
19. current are delayed in time by one-third and two-third of one cycle of the electrical current. This
delay between “phases” has the effect of giving constant power transfer over each cycle of the
current and also makes it possible to produce a rotating magnetic field in an electric motor. At the
power station, an electric generator converts mechanical power into a set of electric currents, one
from each electromagnetic coil or winding of the generator. The current are sinusoidal functions
of time, all at the same frequency but offset in time to give different phases. In a three phase system
the phases are spaced equally, giving a phase separation of one-third one cycle. Generators output
at a voltage that ranges from hundreds of volts to 30,000 volts. At the power station, transformers:
step-up” this voltage to one more suitable for transmission. After numerous further
Conversions in the transmission and distribution network the power is finally transformed to the
standard mains voltage (i.e. the “household” voltage). The power may already have been split into
single phase at this point or it may still be three phase. Where the step-down is 3 phase, the output
of this transformer is usually star Connected with the standard mains voltage being the phase-
neutral voltage. Another system commonly seen in North America is to have a delta connected
secondary with a centre tap on one of the windings supplying the ground and neutral. This allows
for 240V three phase as well as three different single phase voltages 120 V between two of the
phases and neutral , 208 V between the third phase ( known as a wild leg) and neutral and 240 V
between any two phase) to be available
from the same supply.
20. Electrical Generator
An Electrical generator is a device that converts kinetic energy to electrical energy, generally using
electromagnetic induction. The task of converting the electrical energy into mechanical energy is
accomplished by using a motor. The source of mechanical energy may be a reciprocating or turbine
steam engine, water falling through the turbine are made in a variety of sizes ranging from small
1 hp (0.75 kW) units (rare) used as mechanical drives for pumps,Compressors and other shaft
driven equipment, to 2,000,000 hp (1,500,000 kW) turbines used to generate electricity. There are
several classifications for modern steam turbines. Steam turbines are used in all of our major coal
fired power stations to drive the generators or alternators, which produce electricity. The turbines
themselves are driven by steam generated in ‘Boilers’ or ‘steam generators’ as they are sometimes
called. Electrical power station use large stem turbines driving electric generators to produce most
(about 86%) of the world’s electricity.
These centralized stations are of two types: fossil fuel power plants and nuclear power plants. The
turbines used for electric power generation are most often directly coupled to their-generators .As
the generators must rotate at constant synchronous speeds according to the frequency of the electric
21. power system, the most common speeds are 3000 r/min for 50 Hz systems, and 3600 r/min for 60
Hz systems. Most large nuclear sets rotate at half those speeds, and have a 4-pole generator rather
than the more common 2-pole one. Energy in the steam after it leaves the boiler is converted into
rotational energy as it passes through the turbine. The turbine normally consists of several stage
with each stages consisting of a stationary blade (or nozzle) and a rotating blade. Stationary blades
convert the potential energy of the steam into kinetic energy into forces, caused by pressure drop,
which results in the rotation of the turbine shaft. The turbine shaft is connected to a generator,
which produces the electrical energy
PLC (PROGRAMMABLE LOGIC CONTROLLER)
Digital electronic device that uses a programmable memory to store instructions and to implement
specific functions such as logic, sequencing , timing etc to control machine and processes.
22. HISTORY
Control engineering has evolved over time. In the past humans was the main method for controlling
a system. More recently electricity has been used for control and early electrical control was based
on relays. These relays allow power to be switched on and off without a mechanical switch. It is
common to use relays to make simple logical control decisions. The development of low cost
computer has brought the most recent revolution, the Programmable Logic Controller (PLC). The
advent of the PLC began in the 1970s, and has become the most common choice for manufacturing
controls.
SALIENT FEATURES
• Cost effective for controlling complex systems.
• Flexible and can be reapplied to control other systems quickly and easily .
• Computational abilities allow more sophisticated control.
• Trouble shooting aids make programming easier and reduce downtime.
• Reliable components make these likely to operate for years before failure.
PLC HARDWARE
Many PLC configurations are available, even from a single vendor. But, in each of these there are
common components and concepts.
The most essential components are:
Power Supply - This can be built into the PLC or be an external unit.
Common voltage levels required by the PLC (with and without the power supply) are 24Vdc,
120Vac, 220Vac.
23. CPU (Central Processing Unit) - This is a computer where ladder logic is stored and processed.
I/O (Input/Output) - A number of input/output terminals must be provided so that the PLC can
monitor the process and initiate actions.
Indicator lights - These indicate the status of the PLC including power on, program running, and
a fault. These are essential when diagnosing problems.
The configuration of the PLC refers to the packaging of the components.
Rack - A rack is often large (up to 18” by 30” by 10”) and can hold multiple cards. When necessary;
multiple racks can be connected together. These tend to be the highest cost, but also the most
flexible and easy to maintain.
INPUTS AND OUTPUTS
Inputs to, and outputs from, a PLC are necessary to monitor and control a process. Both inputs and
outputs can be categorized into two basic types:
Logical or continuous. Consider the example of a light bulb. If it can only be turned on or off, it is
logical control. If the light can be dimmed to different levels, it is continuous.
Continuous values seem more intuitive, but logical values are preferred because they allow more
certainty, and simplify control. As a result most controls applications (and PLCs) use logical inputs
and outputs for most applications. Hence, we will discuss logical I/O and leave continuous I/O for
later. Outputs to actuators allow a PLC to cause something to happen in a process.
A short list of popular actuators is given below in order of relative popularity.
Solenoid Valves - logical outputs that can switch a hydraulic or pneumatic flow.
Lights - logical outputs that can often be powered directly from PLC output boards.
24. Motor Starters - motors often draw a large amount of current when started, so they
require motor starters, which are basically large relays.
Servo Motors - a continuous output from the PLC can command a variable speed or
position.
Outputs from PLCs are often relays, but they can also be solid state electronics such as
transistors for DC outputs or Triacs for AC outputs.
Continuous outputs require special output cards with digital to analog converters.
Inputs come from sensors that translate physical phenomena into electrical signals.
Typical examples of sensors are listed below in relative order of popularity.
Proximity Switches - use inductance, capacitance or light to detect an object logically.
Switches - mechanical mechanisms will open or close electrical contacts for a logical
signal.
Potentiometer - measures angular positions continuously, using resistance.
LVDT (linear variable differential transformer) – measures linear displacement