Adani Power, Tirora- Project Report

A REPORT ON ADANI POWER

MAHARASTHRA LIMITED TIRORA

SUBMITTED BY NAMES :NEMISH KANWAR PAVAN KUMAR REDDY MOHIT SAINANI ID NO’S :2012A4PS305P 2012A3PS156G 2012A1PS417G

Submitted on : 14-6-2014

Instructor : Dr .Kamalesh kumar

A Practice School-I station of

BIRLA INSTITUTE OF TECHNOLOGY AND SCIENCE,PILANI

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ABSTRACT This report concentrates on CSR initiatives, Vision/ Mission of Adani

group, how coal being the main raw material is turned to power and transmitted

for industrial and household purposes, super critical technology, Rankine cycle

and some of the departments in Adani power Maharashtra limited (APML)

Tirora. The observations are possible at Adani power plant which is a division of

five units of 660MW maximum capacity of generation whose functioning is

possible with the help of some individual systems kept together and handled by

all engineers and HOD’s. The main aim is to maximize power generation with

minimum amount of coal being used which is a nightmare to any power industry

in the power sector.

Main part is on how faults being co-ordinated, protection systems

used, excitation system, AVR (automatic voltage regulation), controlling from

operations and control room, chemical treatment of water, testing of water, coal,

fuels, planning and Efficiency Maximization.

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Acknowledgement We thank Dr Kamlesh Kumar for his efforts which led to completion of this

report on time.

We would also like to thank Mr. Prashant Ektake, Animesh Mukhopadhyaya,

and Subba Rao for their time to show us plant and explain to us it’s functioning

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TABLE OF CONTENTS Content Page no.

Introduction 5

Coal to Electricity 17

Rankine Cycle 19

Super Critical Technology 22

EMD BTG-Protection system 24

EMD BTG-Excitation System 31

EMD BTG-AVR 35

Operations 37

Efficiency and Planning 42

Chemical Plant 55

Mechanical Maintenance

Department-Turbine

65

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INTRODUCTION

Adani, a global conglomerate with a presence in multiple businesses across

the globe, has entered the power sector to harbinger a ‘power full’ India. Our

comprehension of the criticality in meeting the power requirement and its crucial

role in ensuring the energy security of India, spurred us to build India’s largest

and among the world’s top 5 single location thermal power plants at Mundra.

Along with thermal power generation, Adani power has made a paradigm

shift by venturing into solar power generation in Gujarat. It is Adani’s endeavor

to empower one and all with clean, green power that is accessible and affordable

for a faster and higher socio-economic development.

We have achieved it with our out-of-the-box thinking, pioneering

operational procedures, motivated team and a yen for trendsetting. Our

enthusiasm and energy has earned us accomplishments that make us the First,

Fastest and Largest power company in many aspects. Adani Power Limited has

commissioned the first supercritical 660 MW unit in India. Mundra is also the

world’s first supercritical technology based thermal power project to have

received ‘Clean Development Mechanism (CDM) Project’ certification from

United Nations Framework Convention on Climate Change (UNFCCC).

Adani power has the fastest turnaround time of projects in the industry.

We are the largest private single location thermal power generating company in

India. To complete the value chain in power supply, Adani has forayed into

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power transmission. Group’s first line to be commissioned was 400 KV, 430 km

long double circuit line from Mundra to Dehgem. Further the group achieved a

landmark with completion of about 1000 km long 500km Bi-pole HVDC line

connecting Mundra in Gujarat to Mohimdevgarh in Haryana. This became the

first HVDC line by a private player in India and connects western grid to

northern grid. Today Adani power has approximately 5500 circuit Km of

transmission lines connecting its Tirora project in Maharashtra with Maharashtra

grid.

The advantageous edge Adani has is the national and international coal

mining rights with its promoter Company Adani Enterprises Limited which

ensures fuel security. Vertical integration within the Adani group shall provide

synergies to the power business and catapult it to electrifying heights of success.

APML Tirora (5*660MW)

Unit Number Installed Capacity (MW) Date of Commissioning Status

1 660 2012 January Running

2 660 2013 March Running

3 660 2013 June Running

4 660 2014 April Running

5 660 Yet to be commissioned

--

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Future Projects As of January 2011, the company has 16500MW under implementation

and planning stage. A few of them are 3300MW coal based TPP at Bhadreswar

in Gujarat, 2640 MW TPP at Dahej in Gujarat, 1320 MW TPP at Chhindwara in

Madhya Pradesh, 2000 MW TPP at Anugul in Orissa and 2000MW gas based

power project at Mundra in Gujarat. The company is also bidding for 1000 MW

of lignite coal based power plant at Kosovo showing its international projects.

Awards and Recognition

“National Energy Conservation Award 2012: Second Prize in Thermal Power

Station Sector” by Ministry of Power (Bureau of Energy Efficiency)

“Quality Excellence Award for Fastest Product Development” by National

Quality Excellence Award, 2012

“Quality Excellence Award for Fastest Growing Company” by National Quality

Excellence Award, 2012

National Award for “Meritorious Performance in Power Sector” in recognition of

outstanding performance during 2011-12 for early completion of the 5th unit of

Mundra Thermal Power Plant by Ministry of Power, Government of India

“Infrastructure Excellence Award 2011” by CNBC TV18 &Essar Steel Award

for “Spearheading the Infra Power sector”

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“National Energy Conservation Award 2011: First Prize in Thermal Power

Station Sector” by Ministry of Power (Bureau of Energy Efficiency)

"The Most Admired Developer in Power Sector“: Two consecutive years (2010

& 2011) by KPMG & Infrastructure Today

Competitive advantage: Integrated business model

India has arrived at the global scenario as an economic power marching

towards progress and prosperity. Its economic growth is not only powered by

Government initiatives but equally supported by Private Industry that is

committing large investments for nation building.

We at Adani, as one of India’s top conglomerates with a clear focus and

investments in infrastructure sector, are also playing our role as a Nation Builder.

While each of our businesses has competitiveness and scale, the value

integration of Coal, Port and Power together provide most desired synergy. This

synergy not only helps us in quick turnaround for our projects but also in

delivering the best value to all our stakeholders. Harnessing our objective of

maximization of value, we have been able to create truly integrated value chain

from the coal pit to plug point.

With two decades of experience in Coal Trading, and having acquired coal

mining rights in India, Australia and Indonesia, we transport coal from and to our

own ports through our own ships and this coal is consumed by our own thermal

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power plant in Mundra; thus covering all aspects of the value chain in the Power

business.

Social Responsibility

With success comes responsibility, so we take care to reinvest in protecting and

developing the communities within which we operate. We live and work in the

communities where our operations are based and take our responsibilities to

society seriously. We invest 3% of our group profit in community initiatives

through the Adani Foundation, CSR arm of Adani group.

The Foundation runs projects in four key areas:

1 Education especially primary education

2 Community Health- Innovation projects to meet local needs. Reaching out with

basic health care to all (bridging the gap).

3 Sustainable livelihood Projects – Holding hands of all marginalized group to

improve livelihood opportunity, thus improving their quality of life.

4 Rural Infrastructure Development- Need based quality infrastructure to

improve quality of life.

How Do We Do It

In the current scenario of climate change and global warming, the usage of

environment friendly technology is an integral part of a project feasibility and

execution. Adani Group is committed towards the energy conservation and

environment while addressing the nation's energy requirements.

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Adani Power created history by synchronizing India's first super-critical

technology based 660 MW generating thermal power unit at Mundra. The

Supercritical power plants operate at higher temperatures and pressures, and

therefore achieve higher efficiencies (above 40%) than conventional sub-critical

power plants (32%). The use of supercritical technology also leads to significant

CO2 emission reductions (above 20%).

- Installing supercritical units - Conserve coal

- Installation of energy efficient LED lighting

- Optimize auxiliary power consumption

- Implementing VFDs

- Improving combustion efficiency

- Minimize system leakages

The implementation of above projects resulted to the following benefits:

- Reduced auxiliary power consumption

- Better Heat Rate

- Reduced consumption of Specific Oil

Adani group has also commissioned a 40 MW solar power plant in Kutch

district, Gujarat. "This plant also marks Adani's first big foray in the renewable

energy sector,"

The selection committee of National Energy Conservation Award – 2011

awarded Mundra Thermal Power Plant the first prize for efficient operations in

the Thermal Power Stations Sector.

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The Phase III of the Mundra power project, which is based on supercritical

technology, has received 'Clean Development Mechanism (CDM) Project'

certification from United Nations Framework Convention on Climate Change

(UNFCCC). This is the world's first project based on supercritical technology to

be registered as CDM Project under UNFCCC.

Green endeavours

We are developing plantation and greenery not only to reduce CO2 emission but

also to become a responsible corporate citizen and to create an environment

friendly setup to have one of the greenest power plants.

A separate department of hoticulture has been established which enables the

following:

- Aid in developing Eco-friendly & the greenest (sustainable) possible Power

Plants.

- Reduce the impact on environment and create a healthy climate and aesthetic

conditions at work by developing a dense green belt in the surrounding area

- Save time and resources by implementing the instant landscape concept to use

green building concept in green zone development to help reduce CO2emission

(Globalwarming)

Green Highlights

- We are pioneers in implementing the latest Iso-Dutch technique in India where

a green zone has been developed in highly saline sandy soil and water (35000-

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45000 TDS). The Green Zone development includes 25845 trees, 392250 shrubs

and 28785 sq. meter green carpet with a survival rate of more than 90% in highly

saline soil base dredged from the sea.

- We have adopted Israel's Hi-Tech Mechanised sprinkler irrigation systems and

also the latest system of underground drip irrigation to deliver water directly to

the root zone to avoid water loss through evaporation. This system saves

irrigation water usage up to 80% as a cost savings initiative.

- Utilise Hi-tech and latest techniques in Horticulture maintenance with

increasing working efficiency with highly productivity initiatives.

- Adopted base greening concept to prevent blowing of sandin high wind

velocity.

- Utilising treated STP water in irrigation & treated sludge into manure in Green

zone development with dual benefits i.e. fulfillment of environmental policy and

economising on irrigation water.

- Implemented productive Green zones with three major benefits such as income

generation, employment and implementation of environment policies.

- Planted ready trees rather than small sapling by using modern technology which

saved time, economy on maintenances and improved environment from the day

they were planted.

Community relations

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Our projects strive to address Millennium Development Goals (MDG) pledged

by U.N. member states which includes:

- Eradicate extreme poverty and hunger

- Achieve universal primary education

- Promote gender equality and empower women

- Reduce child mortality

- Improve maternal health

- Combat HIV/AIDS, malaria and other diseases

- Ensure environment sustainability

- Develop a global partnership for development

A team of committed professionals plan & implement developmental

programmes in communities with their support and participation.

To enableholistic development, work on a number of issues in each community

has been undertaken simultaneously.

Education

To achieve Quality Education amongst Government Primary Schools, Adani

Foundation provides support in the areas of infrastructure improvement and

material support to make schooling more attractive & meaningful, encouraging

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community participation and various programmes to make education fun and

interesting. This includes building extra room, improving/beautifying school and

or making school safe with fencing or boundary. Reading Corner - to inculcate

reading habit amongst kids and Health Corner - for healthy and hygienic habits,

have been introduced in Government Primary Schools.

Community health

Arranging multi- disciplinary medical camps at villages has earned us the

admiration of thousands of villagers in just couple of months. Our community

mobilisers and project officers strive to spread the awareness on health and

sanitation issues with women groups and youth groups. We are also promoting

the Kitchen Garden concept to improve the nutritional status of the families.

Sustainable livelihood projects

We undertake many initiatives to provide diverse livelihood avenues within the

community. The various Sustainable Livelihood Programmes we run are based

on multiple studies and observations. We aim to make the livelihood of people in

the community sustainable in three ways:

1) Increase income if they are already earning

2) Equip them to earning if they are unemployed

3) Encourage savings

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We have also taken up various skills development initiatives for women and

youth, introduced innovative techniques in Agriculture, provide support for

common well and farm pond deepening. In other initiatives, capacity building for

various Village Institutions and groups has also been undertaken.

Rural infrastructure development

Infrastructure projects like hand pump installation, repairing public wells,

Anganwadi buildings; overhead water tank, water pipe lines construction etc

have been completed as part of this initiative.

Vision

To be the globally admired leader in integrated Infrastructure businesses

with a deep commitment to nation building. We shall be known for our scale of

ambition, speed of execution and quality of operation.

Values

Courage: we shall embrace new ideas and businesses

Trust: we shall believe in our employees and other stakeholders

Commitment: we shall stand by our promises and adhere to high standard of

business

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Coal to Electricity

Coal

Chemical Energy

Super Heated

Pollutant

Thermal Energy

Turbine Torque

Heat Loss In

Condenser

Kinetic Energy

Electrical Energy

Alternating current in

Mech. Energy Loss ASH Heat

Elet. Energy Loss

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A coal power station turns the chemical energy in coal into electrical

energy that can be used in homes and businesses.

First the coal is ground to a fine powder and blown into the boiler, where it

is burned, converting its chemical energy into heat energy. Grinding the coal into

powder increases its surface area, which helps it to burn faster and hotter,

producing as much heat and as little waste as possible.

As well as heat, burning coal produces ash and exhaust gases. The ash falls

to the bottom of the boiler and is removed by the ash systems. It is usually then

sold to the building industry and used as an ingredient in various building

materials, like concrete.

The gases enter the exhaust stack which contains equipment that filters out

any dust and ash, before venting into the atmosphere. The exhaust stacks of coal

power stations are built tall so that the exhaust plume can disperse before it

touches the ground. This ensures that it does not affect the quality of the air

around the station.

Burning the coal heats water in pipes coiled around the boiler, turning it

into steam. The hot steam expands in the pipes, so when it emerges it is under

high pressure. The pressure drives the steam over the blades of the steam turbine,

causing it to spin, converting the heat energy released in the boiler into

mechanical energy.

A shaft connects the steam turbine to the turbine generator, so when the

turbine spins, so does the generator. The generator uses an electromagnetic field

to convert this mechanical energy into electrical energy.

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After passing through the turbine, the steam comes into contact with pipes

full of cold water. In coastal stations this water is pumped straight from the sea.

The cold pipes cool the steam so that it condenses back into water. It is then

piped back to the boiler, where it can be heated up again, turn into steam again,

and keep the turbine turning.

Finally, a transformer converts the electrical energy from the generator to

a high voltage. The national grid uses high voltages to transmit electricity

efficiently through the power lines to the homes and businesses that need it.

Here, other transformers reduce the voltage back down to a usable level.

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RANKINE CYCLE

The Rankine cycle is a model that is used to predict the performance of

steam engines. The Rankine cycle is an idealisedthermodynamic cycle of a heat

engine that converts heat into mechanical work. The heat is supplied externally to

a closed loop, which usually uses water as the working fluid. The Rankine cycle,

in the form of steam engines, generates about 90% of all electric power used

throughout the world, including virtually all biomass, coal, solar thermal and

nuclear power plants. It is named after William John Macquorn Rankine, a

Scottish polymath and Glasgow University professor.

The Rankine cycle closely describes the process by which steam-operated

heat engines commonly found in thermalpower generation plants generate power.

The heat sources used in these power plants are usually nuclear fission or the

combustion of fossil fuels such as coal, natural gas, and oil.

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The efficiency of the Rankine cycle is limited by the high heat of

vaporization of the working fluid. Also, unless the pressure and temperature

reach super critical levels in the steam boiler, the temperature range the cycle can

operate over is quite small: steam turbine entry temperatures are typically 565°C

(the creep limit of stainless steel) and steam condenser temperatures are around

30°C. This gives a theoretical maximum Carnot efficiency for the steam turbine

alone of about 63% compared with an actual overall thermal efficiency of up to

42% for a modern coal-fired power station. This low steam turbine entry

temperature (compared to a gas turbine) is why the Rankine (steam) cycle is

often used as a bottoming cycle to recover otherwise rejected heat in combined-

cycle gas turbine power stations.

The working fluid in a Rankine cycle follows a closed loop and is reused

constantly. The water vapor with condensed droplets often seen billowing from

power stations is created by the cooling systems (not directly from the closed-

loop Rankine power cycle) and represents the means for (low temperature) waste

heat to exit the system, allowing for the addition of (higher temperature) heat that

can then be converted to useful work (power). This 'exhaust' heat is represented

by the "Qout" flowing out of the lower side of the cycle shown in the T/s diagram

below. Cooling towers operate as large heat exchangers by absorbing the latent

heat of

Vaporization of the working fluid and simultaneously evaporating cooling water

to the atmosphere. While many substances could be used as the working fluid in

the Rankine cycle, water is usually the fluid of choice due to its favorable

properties, such as its non-toxic and unreactive chemistry, abundance, and low

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cost, as well as its thermodynamic properties. By condensing the working steam

vapor to a liquid the pressure at the turbine outlet is lowered and the energy

required by the feed pump consumes only 1% to 3% of the turbine output power

and these factors contribute to a higher efficiency for the cycle. The benefit of

this is offset by the low temperatures of steam admitted to the turbine(s). Gas

turbines, for instance, have turbine entry temperatures approaching 1500°C.

However, the thermal efficiencies of actual large steam power stations and large

modern gas turbine stations are similar.

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SUPER CRITICAL TECHNOLOGY

“Supercritical " is a thermodynamic

expression describing the state of a

substance where there is no clear

distinction between the liquid and the

gaseous phase (i.e. they are a

homogenous fluid). Water reaches this

state at a pressure above around 220

Kg Bar (225.56 Kg / cm2) and

Temperature = 374.15 C.

In addition, there is no surface tension in a supercritical fluid, as there is

no liquid/gas phase boundary.

By changing the pressure and temperature of the fluid, the properties can

be “tuned” to be more liquid- or more gaslike. Carbon dioxide and water are the

most commonly used supercritical fluids, being used for decaffeination and

power generation, respectively.

Up to an operating pressure of around 190Kg Bar in the evaporator part of

the boiler, the cycle is Sub-Critical. In this case a drum-type boiler is used

because the steam needs to be separated from water in the drum of the boiler

before it is

Superheated and led into the turbine.

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Above an operating pressure of 220Kg Bar in the evaporator part of the

Boiler, the cycle is Supercritical. The cycle medium is a single phase fluid with

homogeneous properties and there is no need to separate steam from water in a

drum.

Thus, the drum of the drum-type boiler which is very heavy and located

on the top of the boiler can be eliminated

Once-through boilers are therefore used in supercritical cycles.

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EMD (electrical maintenance department) – BTG

In this particular department brief introduction to following will be given 1. Power- systems Protection

2. Excitation systems

3. AVR (automatic voltage regulation)

POWER-SYSTEM PROTECTION

Power-system protection is a branch of electrical power engineering that

deals with the protection of electrical power systems from faults through the

isolation of faulted parts from the rest of the electrical network. The objective of

a protection scheme is to keep the power system stable by isolating only the

components that are under fault, whilst leaving as much of the network as

possible still in operation. Thus, protection schemes must apply a very pragmatic

and pessimistic approach to clearing system faults. For this reason, the

technology and philosophies utilized in protection schemes can often be old and

well-established because they must be very reliable.

Protection systems usually comprise five components:

- Current and voltage transformers to step down the high voltages and currents

of the electrical power system to convenient levels for the relays to deal with.

- Protective relays to sense the fault and initiate a trip, or disconnection, order.

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- Circuit breakers to open/close the system based on relay and autorecloser

commands.

- Batteries to provide power in case of power disconnection in the system.

- Communication channels to allow analysis of current and voltage at remote

terminals of a line and to allow remote tripping of equipment.

For parts of a distribution system, fuses are capable of both sensing and

disconnecting faults.

Failures may occur in each part, such as insulation failure, fallen or

broken transmission lines, incorrect operation of circuit breakers, short circuits

and open circuits. Protection devices are installed with the aims of protection of

assets, and ensure continued supply of energy.

Switchgear is a combination of electrical disconnects switches, fuses or

circuit breakers used to control, protect and isolate electrical equipment.

Switches are safe to open under normal load current, while protective devices are

safe to open under fault current.

- Protective relays control the tripping of the circuit breakers surrounding the

faulted part of the network

- Automatic operation, such as auto-reclosing or system restart

- Monitoring equipment which collects data on the system for post event

analysis

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While the operating quality of these devices, and especially of protective relays,

is always critical, different strategies are considered for protecting the different

parts of the system. Very important equipment may have completely redundant

and independent protective systems, while a minor branch distribution line may

have very simple low-cost protection.

There are three parts of protective devices:

- Instrument transformer: current or potential (CT or VT)

- Relay

- Circuit breaker

Advantages of protected devices with these three basic components

include safety, economy, and accuracy.

- Safety: Instrument transformers create electrical isolation from the power

system, and thus establishing a safer environment for personnel working with

the relays.

- Economy: Relays are able to be simpler, smaller, and cheaper given lower-

level relay inputs.

- Accuracy: Power system voltages and currents are accurately reproduced by

instrument transformers over large operating ranges.

Types of Protection

- Generator sets – In a power plant, the protective relays are intended to prevent

damage to alternators or to the transformers in case of abnormal conditions of

operation, due to internal failures, as well as insulating failures or regulation

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malfunctions. Such failures are unusual, so the protective relays have to

operate very rarely. If a protective relay fails to detect a fault, the resulting

damage to the alternator or to the transformer might require costly equipment

repairs or replacement, as well as income loss from the inability to produce

and sell energy.

- High-voltage transmission network – Protection on the transmission and

distribution serves two functions: Protection of plant and protection of the

public (including employees). At a basic level, protection looks to disconnect

equipment which experiences an overload or a short to earth. Some items in

substations such as transformers might require additional protection based on

temperature or gas pressure, among others.

- Overload and back-up for distance (overcurrent) – Overload protection

requires a current transformer which simply measures the current in a circuit.

There are two types of overload protection: instantaneous overcurrent and

time overcurrent (TOC). Instantaneous overcurrent requires that the current

exceeds a predetermined level for the circuit breaker to operate. TOC

protection operates based on a current vs time curve. Based on this curve if

the measured current exceeds a given level for the preset amount of time, the

circuit breaker or fuse will operate.

- Earth fault ("ground fault" in the United States) – Earth fault protection again

requires current transformers and senses an imbalance in a three-phase circuit.

Normally the three phase currents are in balance, i.e. roughly equal in

magnitude. If one or two phases become connected to earth via a low

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impedance path, their magnitudes will increase dramatically, as will current

imbalance. If this imbalance exceeds a pre-determined value, a circuit breaker

should operate. Restricted earth fault protection is a type of earth fault

protection which looks for earth fault between two sets current transformers

(hence restricted to that zone).

- Distance (impedance relay) – Distance protection detects both voltage and

current. A fault on a circuit will generally create a sag in the voltage level. If

the ratio of voltage to current measured at the relay terminals, which equates

to impedance, lands within a predetermined level the circuit breaker will

operate. This is useful for reasonable length lines, lines longer than 10 miles,

because its operating characteristics are based on the line characteristics. This

means that when a fault appears on the line the impedance setting in the relay

is compared to the apparent impedance of the line from the relay terminals to

the fault. If the relay setting is determined to be below the apparent

impedance it is determined that the fault is within the zone of protection.

When the transmission line length is too short, less than 10 miles, distance

protection becomes more difficult to coordinate. In these instances the best

choice of protection is current differential protection.

- Back-up – The objective of protection is to remove only the affected portion

of plant and nothing else. A circuit breaker or protection relay may fail to

operate. In important systems, a failure of primary protection will usually

result in the operation of back-up protection. Remote back-up protection will

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generally remove both the affected and unaffected items of plant to clear the

fault. Local back-up protection will remove the affected items of the plant to

clear the fault.

- Low-voltage networks – The low-voltage network generally relies upon fuses

or low-voltage circuit breakers to remove both overload and earth faults.

Coordination

Protective device coordination is the process of determining the "best fit"

timing of current interruption when abnormal electrical conditions occur. The

goal is to minimize an outage to the greatest extent possible. Historically,

protective device coordination was done on translucent log–log paper. Modern

methods normally include detailed computer based analysis and reporting.

Protection coordination is also handled through dividing the power system

into protective zones. If a fault were to occur in a given zone, necessary actions

will be executed to isolate that zone from the entire system. Zone definitions

account for generators, buses, transformers, transmission and distribution lines,

and motors. Additionally, zones possess the following features: zones overlap,

overlap regions denote circuit breakers, and all circuit breakers in a given zone

with a fault will open in order to isolate the fault. Overlapped regions are created

by two sets of instrument transformers and relays for each circuit breaker. They

are designed for redundancy to eliminate unprotected areas; however, overlapped

regions are devised to remain as small as possible such that when a fault occurs

in an overlap region and the two zones which encompass the fault are isolated,

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the sector of the power system which is lost from service is still small despite two

zones being isolated.

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EXCITATION SYSTEM

INTRODUCTION

All synchronous machines excepting certain machines like permanent

magnet generators require a DC supply to excite their field winding. As

synchronous machine is a constant speedy machine for a constant frequency

supply, the output voltage of the machine depends on the excitation current. The

control of excitation current for maintaining constant voltage at generator output

terminals started with control through a field rheostat, the supply being obtained

from DC Exciter. The modern trend in interconnected operation of power

systems for the purpose of reliability and in increasing unit size of generators for

the purposes of economy has been mainly, responsible for the evolution of new

excitation schemes.

Former practice, to have an excitation bus fed by a number of exciters

operating in parallel and supplying power to the fields of all the alternators in the

station, is now obsolete.The present practice is unit exciter scheme, i.e. each

alternator to have its own exciter.However in some plants reserve bus

exciter/stand by exciter also provided in case of failure of unit exciter.

Exciter should be capable of supplying necessary excitation for alternator in

a reasonable period during normal and abnormal conditions, so that alternator

will be in synchronism with the grid.

Under normal conditions, exciter rating will be in the order of 0.3 to 0.6%

of generator rating (approx.). Its rating also expressed in 10 to 15 amp. (approx.)

per MW at normal load. Under field forcing conditions exciter rating will be 1 to

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1.5% (approx) of the generator rating. Typical exciter ratings for various capacity

of generators are as given below:

TYPES OF THE EXCITATION SYSTEM

There are two types of Excitation System. These are mainly classified as (i)

Dynamic exciter (rotating type) (ii) Static Exciter (static type). The different

types excitation which are being used are indicated as given below :

(1) (a) Separately Excited (thro' pilot exciter) (DC) Excitation System

(b) Self Excited (shunt) (DC) Excitation System

(2) High frequency AC Excitation System

(3) Brushless Excitation System

(4) Static Excitation System

Among the above types of exciters, Static excitation system plays a very

important roll in modern interconnected power system operation due to its fast

acting, good response in voltage & reactive power control and satisfactory steady

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state stability condition. For the machines 500 MW& above and fire hazards

areas, Brushless Excitation System is preferred due to larger requirement of

current & plant safety respectively.

STATIC EXCITATION SYSTEM:

In order to maintain system stability in interconnected system network it is

necessary to have fast acting excitation system for large synchronous machines

which means the field current must be adjusted extremely fast to the changing

operational conditions. Besides maintaining the field current and steady state

stability the excitation system is required to extend the stability limits. It is

because of these reasons the static excitation system is preferred to conventional

excitation systems.

In this system, the AC power is tapped off from the generator terminal

stepped down and rectified by fully controlled thyristor Bridges and then fed to

the generator field thereby controlling the generator voltage output. A high

control speed is achieved by using an internal free control and power electronic

system. Any deviation in the generator terminal voltage is sensed by an error

detector and causes the voltage regulator to advance or retard the firing angle of

the thyristors thereby controlling the field excitation of the alternator.

Static Excitation system can be designed without any difficulty to achieve

high response ratio which is required by the system. The response ratio in the

order

of 3 to 5 -can be achieved by this system.This equipment controls the generator

terminal voltage, and hence the reactive load flow by adjusting the excitation

P a g e | 34

current. The rotating exciter is dispensed with and Transformer & silicon

controlled rectifiers (SCRS) are used which directly feed the field of the

Alternator.

Description of Static Excitation System.

Static Excitation Equipment Consist of

1) Rectifier Transformer

2) SCR output stage

3) Excitation start up & field discharge equipment

4) Regulator and operational control circuits

P a g e | 35

AVR - UN 2010

The Automatic voltage regulator type UN 2010 is an electronic control

module specially designed for the voltage regulation of synchronous machines. It

primarly consists of an actual value converter, a control amplifier with PID

characteristics which compares the actual value with the set reference value and

forms an output proportional to the difference. The output of this module controls

the gate control circuit UN 1001. The module does not have an INBUILT power

supply and derives its power from UN 2004, the pulse intermediate stage and

power supply unit. The AVR works on + 1SVDC supply.

The main features of this module are listed below

a) The AVR comprises of an input circuit which accepts 3 phase voltage signals

of 11OVAC and 3 phase current signals of SA or 1A A.C. It is thus necessary to

use intermediate PT"s and CT"s to transform the generator voltage and current to

the above mentioned values. The module itself contains PT"s and CT"s with

further step down the signals to make them compatible with electronic circuit. A

CIRCUITARY is available in the module for adding the current signals

VECTORIALY to the voltage signals for providing compensation as a function

of

active or reactive power flowing in the generator terminals.

b) An actual value converting circuit for converting the AC input signal to DC

signal with minimum ripple with the aid of filter network.

P a g e | 36

c) A reference value circuit using temperature compensated zener diodes. The

output of which is taken to an external potentiometer that provides 90-

110%range of operation of the generator voltage.

d) A control amplifier which compares the reference and actual value and

provides an output proportional to the deviation. Apart from this, it has the

facility to accept

other inputs for operation in conjunction with various limiters and power system

stabilizer.

e) A voltage proportional to frequency network which reduces the excitation

current when frequency falls below the set level, thus keeping the air gap flux

constant. This prevents saturation of connected transformers and possible over

voltage

P a g e | 37

OPERATIONS

Every single parameter of any machine in a power plant can be seen

from operations room. From the operations room one can stop/start any machine

Just by a click, they can also monitor input to get desired output which is power.

Some operations which can be done from operations room are given below :

BOILER MENU - Boiler spray water system

- Mill operation system

- Mill A to Mill H system

- FSSS ( furnace supervisory safeguard system ) view

- HFO & LDO leakage test

- Boiler fuel oil system

- Boiler air and flue gas system

- Boiler flue gas system

- Secondary air system

- Primary air &seal oil system

- APH oil system

- FD fan and oil system

- ID fan and oil system

- PA fan and oil system

- Seal air fan system

P a g e | 38

- Scanner air fan system

- Secondary air damper system

- Boiler startup system

- Boiler drain and vent system

- Boiler soot blowing system

- Instrument air system

- Boiler metal temperature

- CCS ( coordinator control system ) overview

- LDO forwarding system

- HFO forwarding system

- Air compresser system

- Boiler fuel oil system – LDO

- TRICON alarm monitor

- Parameters

TURBINE MENU

- Main and reheat steam system - Turbine and BFPT ( Boiler feed pump turbine ) - Turbine and BFPT shaft seal and drain system - Feed water system - Vaccum pump system - HP heater drain and vent system - LP heater drain and vent system

P a g e | 39

- Extraction steam system

- Condenser circulating water system

- Auxiliary cooling water system

- Closed cooling water system

- Auxiliary steam system

- Condesate water system

- Condensate storage and make-up system

- Turbine lube oil system

- Turbine oil conditioning system

- BFP turbine A ( agra ) & B ( Bombay ) lube oil system

- BFP turbine EH ( electro hydrolic ) oil system

- Gen hydrogen and CO2 system

- Gen sealing oil system

- Gen stator cooling water system

- Gen winding temp

- Turbine EH oil system

- Turbine drive feed water pump A & B

- Motor drive feed water pump

- Turbine TSI ( turbo supervisor instruments ) & metal temp

- HP & LP bypass

- Circulating water system

- Turbine control loops 1 & 2

P a g e | 40

ECS ( electrical control system ) for unit

- Generator transformer

- 11 KV

- 6.6 KV

- Boiler PCC ( power control cubic )

- Turbine PCC

- CT PCC

- Emergency PCC

- ESP

- UPS

- Battery charge

- GT signal from switchyard

- ST signal from switchyard

- GT1 & UT1 communication

- UT 1A & 1B metering data

- SPS ( special protection scheme ) signal from switchyard

P a g e | 41

COMMON ECS MENU

- Station battery charge

- Station UPS

- Station 1 – 11 kv startup

- Station 1 – 33 kv

- 415v station 1 vent/vc/swyd pdb

- 6.6 kv station 1

- 415v station 1 PCC

- Comm station 1 – 11 kv

- Comm station 1 – ST

- 415v station 3 PCC

- Comm station 3 – 11 kv

- Comm station 3 – ST

- HT ( high tension ) SWGR soft signal unit 1

- HT SWGR soft signal station 1 5% more of rated power can be generated which means 690MW ( 660 +30 ) can be generated but is not advisable .

P a g e | 42

EFFICIENCY AND PLANNING

Super critical technology which has more thermodynamic efficiency than

other power plants that have been using sub critical technology. Here we

achieve a thermodynamic efficiency of about 41-42 %.

BOILER EFFICIENCY :

In boiler the losses are generally in unburnt bottom ash and fly ash .unburnt

in bottom ash 4.6% and in fly ash 0.6%.poor coal mill fineness, erosion of burner

tips burner tilt mechanism not in synchronisation, linkage between bt mechanism

and burner tip failures are some reasons for this and there is also problem due to

incomplete combustion . Some reasons for incomplete combustion are Unbalance

Fuel &PA Flow between Coal Mills Outlet P.F.Pipes Uneven Openings of Aux

Air Dampers at 4 corners of the elevation

Wind box to Furnace D.P .Less

Mills outlet temp low

Amount of excess air is very less

Dry Gas Loss

Design Values

- APH Gas outlet Temp:-143 Deg.C.(Ambient 30 Deg.C)

- Co2 in APH Gas Outlet :- 14%(O2:-5%)

- Reasons for increased Dry Gas Loss

- Poor Heat Absorption in Boilers from Water Walls to APH ,Need ACID

Cleaning of Boiler

P a g e | 43

- More Excess Air

- APH leakage more

- Water Wall Soot Blowing is not effective Soot Blower Alignment

&Pr,Setting to be ensured

Moisture in Coal

- Design Values :10% as Fired Basis

- Heat Rate Deviation in GUHR

- -7Kcal/kwh-For 1% more moisture in coal

- Excessive Water spray on coal at various places in CHP to Coal Bunker

should be avoided

Critical Area of the Unit

- Which mostly affects the Unit Performance

- BOILER

- Air Heater

- Combustion System

- Turbine

- Condenser

- Feed Water Heating System

P a g e | 44

For Better Combustion of the Unit

- Mill Fineness

- +50 about 1-2%

- -200 about 70%

- Coal Mills balanced for Fuel Flow & PA Flow between P.F .Pipes

- Burner Tips OK

- Synchronus Operation of Burner Tilt Mechanism at all four corners of all

Elevations

Turbine Losses

- Friction Losses

- Nozzle Friction

- Blade Friction

- Disc Friction

- Diaphargm Gland &Blade Tip Frciction

- Partial Admission (Throttling)

- Wetness

- Exhaust

P a g e | 45

External Losses

- Shaft Gland Leakage

- Journal &Thurst Bearing

- Governor &Oil Pump

These are the losses that occur in thermal power plants in turbines and

boilers . we have to minimise these losses to get a greater amount of output for a

given input

CONDITION MONITORING:

Condition monitoring (or, colloquially, CM) is the process of monitoring

a parameter of condition in machinery (vibration, temperature etc.), in order to

identify a significant change which is indicative of a developing fault. It is a

major component of predictive maintainance. The use of conditional monitoring

allows maintenance to be scheduled, or other actions to be taken to prevent

failure and avoid its consequences. Condition monitoring has a unique benefit in

that conditions that would shorten normal lifespan can be addressed before they

develop into a major failure. Condition monitoring techniques are normally used

on rotating equipment and other machinery (pumps, electric motors, internal

combustion engines, presses), while periodic inspection using non-destructive

testing techniques and fit for service (FFS) evaluation are used for stationary

plant equipment such as steam boilers, piping and heat exchangers

P a g e | 46

The following list includes the main condition monitoring techniques applied in

the industrial and transportation sectors:

- Vibration condition monitoring and diagnostics

- Lubricant analysis

- Acoustic emission

- Infrared thermography

- Ultrasound emission

- Motor Condition Monitoring and

- Motor current signature analysis (MCSA)

Most CM technologies are being slowly standardized by ASTSM and ISO.

Here in Adani Maharashtra a team of people in switchyard will test the

condition of machines by using condition monitoring method . They here use

vibrational analysis which is based on the mathematical theorem of fourier time

to frequency domain analysis by getting a graph of amplitude vs frequency

By having amplitudes in the desired level the can say that the machine is in

proper working condition

- Motor Condition Monitoring and

- Motor current signature analysis (MCSA) is a most important technique used

in ntpc and some other plants according to the engineers

P a g e | 47

VIBRATIONAL ANALYSIS

The most commonly used method for rotating machines is called a

vibration analysis. Measurements can be taken on machine bearing casings with

accelerometers (seismic or piezo-electric transducers) to measure the casing

vibrations, and on the vast majority of critical machines, with eddy-

current transducers that directly observe the rotating shafts to measure the radial

(and axial) displacement of the shaft. The level of vibration can be compared

with historical baseline values such as former start ups and shutdowns, and in

some cases established standards such as load changes, to assess the severity.

Interpreting the vibration signal obtained is an elaborate procedure that requires

specialized training and experience. It is simplified by the use

of state-of-the-art technologies that provide the vast majority of data analysis

automatically and provide information instead of raw data. One commonly

employed technique is to examine the individual frequencies present in the

signal. These frequencies correspond to certain mechanical components (for

example, the various pieces that make up a rolling-element bearing ) or certain

malfunctions (such as shaft unbalance or misalignment). By examining these

frequencies and their harmonics, the CM specialist can often identify the location

and type of problem, and sometimes the root cause as well. For example, high

vibration at the frequency corresponding to the speed of rotation is most often

due to residual imbalance and is corrected by balancing the machine. As another

example, a degrading rolling-element bearing will usually exhibit increasing

P a g e | 48

vibration signals at specific frequencies as it wears. Special analysis instruments

can detect this wear weeks or even months before failure, giving ample warning

to schedule replacement before a failure which could cause a much longer down-

time. Beside all sensors and data analysis it is important to keep in mind that

more than 80% of all complex mechanical equipment fail accidentally and

without any relation to their life-cycle period.

Most vibration analysis instruments today utilize a Fast Fourier

Transform (FFT) which is a special case of the generalized Discrete Fourier

Transform and converts the vibration signal from its time domain representation

to its equivalent frequency domain representation. However, frequency analysis

(sometimes called Spectral Analysis or Vibration Signature Analysis) is only one

aspect of interpreting the information contained in a vibration signal. Frequency

analysis tends to be most useful on machines that employ rolling element

bearings and whose main failure modes tend to be the degradation of those

bearings, which typically exhibit an increase in characteristic frequencies

associated with the bearing geometries and constructions. Depending on the type

of machine, its typical malfunctions, the bearing types employed, rotational

speeds, and other factors, the CM specialist may use additional diagnostic tools,

such as examination of the time domain signal, the phase relationship between

vibration components and a timing mark on the machine shaft (often known as

a keyphasor), historical trends of vibration levels, the shape of vibration, and

numerous other aspects of the signal along with other information from the

process such as load, bearing temperatures, flow rates, valve positions and

pressures to provide an accurate diagnosis. This is particularly true of machines

P a g e | 49

that use fluid bearings rather than rolling-element bearing. To enable them to

look at this data in a more simplified form vibration analysts or machinery

diagnostic engineers have adopted a number of mathematical plots to show

machine problems and running characteristics, these plots include the bode plot,

the waterfall plot, the polar plot and the orbit time base plot amongst others.

Handheld data collectors and analyzers are now commonplace on non-

critical or balance of plant machines on which permanent on-line vibration

instrumentation cannot be economically justified. The technician can collect data

samples from a number of machines, then download the data into a computer

where the analyst (and sometimes artificial intelligence) can examine the data for

changes indicative of malfunctions and impending failures. For larger, more

critical machines where safety implications, production interruptions (so-called

"downtime"), replacement parts, and other costs of failure can be appreciable

(determined by the criticality index), a permanent monitoring system is typically

employed rather than relying on periodic handheld data collection. However, the

diagnostic methods and tools available from either approach are generally the

same.

Recently also on-line systems have been applied to heavy process industries

such as pulp, paper, mining, petrochemical and power generation. These can

be dedicated systems like Sensodec 6S or nowadays this functionality has been

embedded into DCS.

Performance monitoring is a less well-known condition monitoring

technique. It can be applied to rotating machinery such as pumps and turbines, as

P a g e | 50

well as stationary items such as boilers and heat exchangers. Measurements are

required of physical quantities: temperature, pressure, flow, speed, displacement,

according to the plant item. Absolute accuracy is rarely necessary, but repeatable

data is needed. Calibrated test instruments are usually needed, but some success

has been achieved in plant with DCS (Distributed Control Systems). Performance

analysis is often closely related to energy efficiency, and therefore has long been

applied in steam power generation plants. Typical applications in power

generation could be boiler, steam turbine and gas turbine. In some cases, it is

possible to calculate the optimum time for overhaul to restore degraded

performance.

Other technique

- Often visual inspections are considered to form an underlying component of

condition monitoring, however this is only true if the inspection results can be

measured or critiqued against a documented set of guidelines. For these

inspections to be considered condition monitoring, the results and the

conditions at the time of observation must be collated to allow for

comparative analysis against the previous and future measurements. The act

of simply visually inspecting a section of pipework for the presence of cracks

or leaks cannot be considered condition monitoring unless quantifiable

parameters exist to support the inspection and a relative comparison is made

against previous inspections. An act performed in isolation to previous

inspections is considered a Condition Assessment, Condition Monitoring

P a g e | 51

activities require that analysis is made comparative to previous data and

reports the trending of that comparison.

- Slight temperature variations across a surface can be discovered with visual

inspection and non-destructive testing with thermography. Heat is indicative

of failing components, especially degrading electrical contacts and

terminations. Thermography can also be successfully applied to high-speed

bearings, fluid couplings, conveyor rollers, and storage tank internal build-up.

- Using a Scanning Electron Microscope of a carefully taken sample of debris

suspended in lubricating oil (taken from filters or magnetic chip detectors).

Instruments then reveal the elements contained, their proportions, size and

morphology. Using this method, the site, the mechanical failure mechanism

and the time to eventual failure may be determined. This is called WDA -

Wear Debris Analysis.

- Spectrographic oil analysis that tests the chemical composition of the oil can

be used to predict failure modes. For example a high silicon content indicates

contamination of grit etc., and high iron levels indicate wearing components.

Individually, elements give fair indications, but when used together they can

very accurately determine failure modes e.g. for internal combustion engines,

the presence of iron/alloy, and carbon would indicate worn piston rings.

- Ultrasound can be used for high-speed and slow-speed mechanical

applications and for high-pressure fluid situations. Digital ultrasonic meters

measure high frequency signals from bearings and display the result as a db

uv(decibels per microvolt) value. This value is trended over time and used to

predict increases in friction, rubbing, impacting, and other bearing defects.

P a g e | 52

The dBuV value is also used to predict proper intervals for re-lubrication.

Ultrasound monitoring, if done properly, proves out to be a great companion

technology for vibration analysis.

Headphones allow humans to listen to ultrasound as well. A high pitched

'buzzing sound' in bearings indicates flaws in the contact surfaces, and when

partial blockages occur in high pressure fluids the orifice will cause a large

amount of ultrasonic noise. Ultrasound is used in the Shock Pulse Method of

condition monitoring.

- Performance analysis, where the physical efficiency, performance, or

condition is found by comparing actual parameters against an ideal model.

Deterioration is typically the cause of difference in the readings. After motors,

centrifugal pumps are arguably the most common machines. Condition

monitoring by a simple head-flow test near duty point using repeatable

measurements has long been used but could be more widely adopted. An

extension of this method can be used to calculate the best time to overhaul a

pump based on balancing the cost of overhaul against the increasing energy

consumption that occurs as a pump wears. Aviation gas turbines are also

commonly monitored using performance analysis techniques with the original

equipment manufacturers such as Rolls-Royce plc routinely monitoring whole

fleets of aircraft engines under Long Term Service Agreements (LTSAs) or

Total Care packages.

- Wear Debris Detection Sensors are capable of detecting ferrous and non-

ferrous wear particles within the lubrication oil giving considerable

P a g e | 53

information about the condition of the measured machinery. By creating and

monitoring a trend of what debris is being generated it is possible to detect

faults prior to catastrophic failure of rotating equipment such as gearbox',

turbines, etc.

The Criticality Index

- The Criticality Index is often used to determine the degree on condition

monitoring on a given machine taking into account the machines

purpose, redundancy (i.e. if the machine fails, is there a standby machine

which can take over), cost of repair, downtime impacts, health, safety and

environment issues and a number of other key factors. The criticality index

puts all machines into one of three categories:

1. Critical machinery - Machines that are vital to the plant or process and

without which the plant or process cannot function. Machines in this

category include the steam or gas turbines in a power plant, crude oil

export pumps on an oil rig or the cracker in an oil refinery. With critical

machinery being at the heart of the process it is seen to require full on-line

condition monitoring to continually record as much data from the machine

as possible regardless of cost and is often specified by the plant insurance.

Measurements such as loads, pressures, temperatures, casing vibration and

displacement, shaft axial and radial displacement, speed and differential

expansion are taken where possible. These values are often fed back into a

machinery management software package which is capable of trending the

P a g e | 54

historical data and providing the operators with information such as

performance data and even predict faults and provide diagnosis of failures

before they happen.

2. Essential Machinery - Units that are a key part of the process, but if there is

a failure, the process still continues. Redundant units (if available) fall into

this realm. Testing and control of these units is also essential to maintain

alternative plans should Critical Machinery fail.

3. General purpose or balance of plant machines - These are the machines that

make up the remainder of the plant and normally monitored using a

handheld data collector as mentioned previously to periodically create a

picture of the health of the machine.

This is all about condition monitoring .

Here in APML TIRODA plant there is technical services department .

P a g e | 55

CHEMICAL PLANT

Here they do water purification ,water analysis , coal analysis and oil analysis.

WATER PURIFICATION

Types of water in thermal power plant

- Cooling water

- Boiler water

- Process water

- Consumptive water

Water treatment in power plant

- Pretreatment of water

- Filter water for softening and D M plant

- Ultra pure/ de mineralized water for boiler make up and steam generation

- Cooling water system

WATER FLOW DIAGRAM

Raw water clariflocculator gravity filter u/g storage tank dm

plant boler make up

P a g e | 56

Actually in pretreatment of water suspended particles colloidal silica and

some other organic materials are removed

Here alum +cl2 is added to raw water.then water is sent through

clariflocculator . there the water is clarified and the sludge is settled in the

bottom. from there the water is sent through psf [PRESSURISED SAND

FILTER]and degaseer where dissolved gases are sent out like co2 and NOX.

Then from there the water is sent for reverse osmosis where again dissolved

gases and ions are removed and from there the water is sent for ultra filtration.

From there the water is sent through cation resin and anion resign where both

cation and anion impurities like Na ,Mg,Al,PO4etc are removed.

Then the water is sent through mixed bed and from there the water is

directly sent to the DM water storage tanks which have a capacity of about

3000m^3.

Before going to the dm plant sorage tank the chemical people will do

chemical analysis of water in the laboratory as follows

The following parameters are monitored in the laboratory

- pH 9.0-9.6

- sillica as sio2 <15ppm

- conductivity <9

- after cation conductivity

- dissolved oxygen <7

P a g e | 57

- sodium

- copper

- iron <10

- carbondioxide

- hardness

- chloride

For some parameters limited are mentioned above as per my knowledge

.for every quantity the values should be within the permissible limits .otherwise

the water sample will be rejected to sent in to the boiler.

OIL ANALYSIS

According to the national auronatic standard the NAS value of the oil

should be less than 7.And the moisture should be less than 100 ppm and the Total

Acid Number is 0.02 mgkoh/gm.

Oil analysis (OA) is the laboratory analysis of a lubricant's properties,

suspended contaminants, and wear debris.OA is performed during

routine preventive maintenance to provide meaningful and accurate information

on lubricant and machine condition. By tracking oil analysis sample results over

the life of a particular machine, trends can be established which can help

eliminate costly repairs. The study of wear in machinery is called tribology

OA can be divided into three categories:

1. analysis of oil properties including those of the base oil and its additives,

P a g e | 58

2. analysis of contaminants,

3. analysis of wear debris from machinery,

Viscosity index (VI) is an arbitrary measure for the change of viscosity with

variations in temperature. It is used to characterize viscosity changes with

relation to temperature in lubricating oil.

A viscometer (also called viscosimeter) is an instrument used to measure

the viscosity of a fluid. For liquids with viscosities which vary with flow

conditions, an instrument called a rheometer is used. Viscometers only measure

under one flow condition. a viscometer in our laboratory at APML ,TIRODA

A coulometer is a device to determine electric charges. The term comes

from the unit of charge, the coulomb. There can be two goals in measuring

charge:

- Coulometers can be devices that are used to determine an amount of

substance by measuring the charges. The devices do a quantitative analysis.

This method is called coulometry, and related coulometers are either devices

used for a coulometry or instruments that perform a coulometry in an

automatic way.

- Coulometers can be used to determine electric quantities in the direct current

circuit, namely the total charge or a constant current. These devices invented

by Michael Faraday were used frequently in the 19th century and in the first

half of the 20th century. In the past, the coulometers of that type were

named voltammeters model of a karl fischer coulometer in our lab

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A model of oil cleanliness meter used in our laboratory

This is the total of oil analysis in our laboratory

The oils used in our plant are

1.heavy fuel oil [HFO]

2.low density oil [LDO]

3.High speed diesel oil [HDO]

COAL ANALYSIS

Coal is a important and essential input in our plant. Therefore its quality

and property is utmost important to us. Therfore coal analysis is done by our lab

members and also by third party to come to a common agreement.If the coal

quality is not to our requirement then we can reject the coal sample .Because

quality of coal maintains an important role in the amount of out put.

Coal is mined by two ways

- Surface mining

- Underground mining

In coal there are many types peat,lignite ,bituminous coal,semi bituminous

coal,non bituminous coal ,anthracite and graphite. Anthracite is the highest coal.

P a g e | 60

Hilt's law is a geological term that states that, in a small area, the deeper the

coal, the higher its rank (grade). The law holds true if the thermal gradient is

entirely vertical, but metamorphism may cause lateral changes of rank,

irrespective of depth.

In coal we mainly measure the following parameters

- Calorific value

- Grade of coal [UHV]

- Proximate analysis

- Ultimate analysis

- Ash and minerals

- Grindability

- Rank

- Physical charcteristics

If ash content is high means total carbon content is less and the coal is not

good to us. And also for us the coal calorific value also should be high so that we

can produce large amount of heat from small amount of coal

The energy value of coal, or the fuel content, is the amount of potential

energy in coal that can be converted into actual heating ability. The value can be

calculated and compared with different grades of coal or even other materials.

Materials of different grades will produce differing amounts of heat for a

given mass.

P a g e | 61

While chemistry provides methods of calculating the heating value of a

certain amount of a substance, there is a difference between this theoretical value

and its application to real coal. The grade of a sample of coal does not precisely

define its chemical composition, so calculating the actual usefulness of coal as a

fuel requires determining its proximate and ultimate analysis

Chemical composition

Chemical composition of the coal is defined in terms of its proximate and

ultimate (elemental) analyses. The parameters of proximate analysis

are moisture, volatile matter, ash, and fixed carbon. Elemental or ultimate

analysis encompasses the quantitative determination

of carbon, hydrogen, nitrogen, sulfur and oxygen within the coal. Additionally,

specific physical and mechanical properties of coal and

particular carbonization properties

The calorific value Q of coal [kJ/kg] is the heat liberated by its

complete combustion with oxygen. Q is a complex function of the elemental

composition of the coal. Q can be determined experimentally using calorimeters.

Dulong suggests the following approximate formula for Q when the oxygen

content is less than 10%:

Q = 337C + 1442(H - O/8) + 93S,

where C is the mass percent of carbon, H is the mass percent of

hydrogen, O is the mass percent of oxygen, andS is the mass percent of sulfur

in the coal. With these constants, Q is given in kilojoules per kilogram.

P a g e | 62

Useful heat value of coal is uhv=8900-138(A+M)

A bomb calorimeter is used to measure the calorific value of the coal

Instruments used to do proximate analysis and ultimate analysis of coal in

the laboratory.

If there is moisture in the coal it is disadvantageous to us as it will reduce

the temperature in the fire ball.so a less amount of moisture is advisable.

Preventive maintenance [Planning]

Preventive maintenance (PM) has the following meanings:

1. The care and servicing by personnel for the purpose of maintaining

equipment and facilities in satisfactory operating condition by providing

for systematic inspection, detection, and correction of incipient failures

either before they occur or before they develop into major defects.

2. Maintenance, including tests, measurements, adjustments, and parts

replacement, performed specifically to prevent faults from occurring.

The primary goal of maintenance is to avoid or mitigate the consequences of

failure of equipment. This may be by preventing the failure before it actually

occurs which Planned Maintenance and Condition Based Maintenance help to

achieve. It is designed to preserve and restore equipment reliability by replacing

worn components before they actually fail. Preventive maintenance activities

P a g e | 63

include partial or complete overhauls at specified periods, oil changes,

lubrication and so on. In addition, workers can record equipment deterioration so

they know to replace or repair worn parts before they cause system failure. The

ideal preventive maintenance program would prevent all equipment failure

before it occurs

Preventive maintenance can be described as maintenance of equipment or

systems before fault occurs. It can be divided into two subgroups:

- planned maintenance and

- condition-based maintenance.

The main difference of subgroups is determination of maintenance time, or

determination of moment when maintenance should be performed.

While preventive maintenance is generally considered to be worthwhile, there

are risks such as equipment failure or human error involved when performing

preventive maintenance, just as in any maintenance operation. Preventive

maintenance as scheduled overhaul or scheduled replacement provides two of the

three proactive failure management policies available to the maintenance

engineer. Common methods of determining what Preventive (or other) failure

management policies should be applied are; OEM recommendations,

requirements of codes and legislation within a jurisdiction, what an "expert"

thinks ought to be done, or the maintenance that's already done to similar

equipment, and most important measured values and performance indications.

P a g e | 64

In a nutshell:

- Preventive maintenance is conducted to keep equipment working and/or

extend the life of the equipment.

- Corrective maintenance, sometimes called "repair," is conducted to get

equipment working again.

P a g e | 65

MECHANICAL MAINTAINANCE [TURBINE]