3. Company Profile :
BTPS is owned by the government of India, under the ministry of energy
and is managed by NTPC since April 1st
, 1978.
BTPS was conceived in 1965 to meet the growing electricity demand of
northern region.
BTPS has mainly five units: -
(i) Unit--I, II & III of 95 MW &
(ii) Unit--IV & V of 210 MW.
↬ IMPORTANT TERMS OF BTPS : -
Approved Capacity : 705MW.
Installed Capacity : 705MW.
Location : New Delhi.
Coal Source : General coal field Ltd., Jharia coal mines.
Oil Source : Indian Oil.
Beneficial State : Delhi.
6. (1) SAFE OPERATION OF PLANT.
(2) LOWEST COST OF GENERATION.
(3) LONGEST EQUIPMENT LIFE.
(4) MINIMUM ENVIROMENTAL EFFECTS.
(5) MAXIMUM EFFICIENCY.
(6) ENERGY CONSERVATION.
“INSTRUMENTATION is a branch which measure & control physical &
chemical parameter at a desire value on order to optimize process
efficiency with improve & uniform product quality & reduce waste & cost
& increased intrinsic safety.”
↬ Instruments are mainly of three types: -
(i) Mechanical,
(ii) Electrical &
(iii) Electronics.
OBJECTIVE OF INSTRUMENTATION & CONTROL
7. Instrument can be classified by as following: -
(a) Primary: - These give the value in terms of physical constant.
(b) Secondary: -
This division is to calibrate various instruments & take care of any
faults that occur in any of the auxiliaries in the plant.
↬ It has the following labs under it in which we get the knowledge about various
processes that are required to run a power plant with instrument under control: -
1. Manometery Lab.
2. Pyrometery Lab.
3. Protection & Interlocks Lab.
4. Water treatment plant (WTP).
5. Furnace safety supervision system (FSSS).
6. Turbine safety supervision system (TSSS).
7. Electronics Lab.
8. Automation Lab.
OVERVIEW OF INSTRUMENTATION &
CONTROL: -
8. (1)(1) MANOMETERYMANOMETERY
LABLAB:
In this lab, we basically deal with the following physical properties like
pressure, level and flow of water or air.
Many techniques have been developed for the measurement of pressure,
vacuum, flow, level, humidity etc. Instruments used to measure pressure are
called pressure gauges or vacuum gauges.
eg.
(1) C-type bourdon tube.
(2) Spiral type.
(3) Diaphragms.
9. (1) Ferromagnetic recorder or indicator: -
The FMI or FMRs
are versatile miniature instrument for the measurement, record & control of such
process variables as pressure, vacuum, level, flow, angle of rotation, etc. These
instruments work in conjunction with primary transmitters incorporated with
differential transformer or ferrodynamic transducers. This presents immense &
exciting possibilities in the field of instrumentation. Principle & working depends
on the chart drive mechanism.
(2) FUJI FCX Series: -
The FCX-A series transmitter, which is available as an
analog or smart type, detects the differential pressure or pressure of various fluids,
converts it into a current signal of 4 to 20 mA DC & transmits it.
Displacement
I/p diffr. Capacitance
DDd
O/P
PressurePressure DETECTING UNITDETECTING UNIT ChangeChange TRANSMISSION UNITTRANSMISSION UNIT
CCurrent
PRESSURE INSTRUMENTS USED IN
BTPS: -
Diaphragm Sensor Measurin
g
ckt
Operational
Amplification
ckt
10. (3) Microcontroller based Bar graph Indicator: -
The user
from PYROTECH ELECTRONICS PRIVATE LTD is fully programmable universal input Bar
graph indicator which can also be used as universal controller or universal converter.
FEATURES: -
(i) High accuracy and reliability.
(ii) Microcontroller based.
(iii) Universal input: - It accepts all standard thermocouple, RTD Pt-100, 4 to 20 mA,
0 to 20 mA, 0-5 V, 1-5 V DC.
(vi) Relevant error message displayed on event of an error.
(vii) Data lock facility (optional).
(4) Ferrodynamic pressure transducers: -
They are used for
measurement of pressure of non-corrosive gases, vapours & liquids in conjunction with
ferrodynamic monitoring recorder or indicator & converter (FMC).
This
instrument is made by using the bourdon tube as pressure sensing element. This can
also be used for control of pressure in conjunction with electric controller type LC-12.
PRESSURE INSTRUMENTS USED ………
11. (5) MICROCONTROLLER BASED DIGITAL CONTROLLERS: -
The microcontroller from PEPL is
based on ON/OFF controller. This controller offers the highest system reliability &
software function capabilities.
(i) Supply voltage: - 110/230V AC, 50 Hz frequency.
(ii) Input: - universal thermocouple E,J,K,T,B,R,S, Pt-100 RTD, 4-20mA, 0-20mA DC, 0-
5V,
1-5V DC.
(iii) Setting method: - Digital setting with SEL, MODE, UP, DOWN keys.
(iv) Display: - 0.3” 7-segment LED display, red colour.
FLOW INSTRUMENTS USED IN BTPS: -
(1) Mechanical flow meters.
(2) Optical flow meters.
(3) Turbine flow meters.
(4) Thermal mass flow meters.
(5) Magnetic flow meters.
(6) Vortex flow meters.
Continue…….
12. Paperless Recorder
The OMEGA® RD8900 Series paperless
recorder offers real time display of data in a
variety of formats on a high resolution (VGA)
color TFT display.
The user friendly unit with plug & play cards
can easily be set to monitor, record, and
evaluate any application.
The user can access data on the screen, as well
as from a remote site via the standard
ethernet or optional RS232/422/485 serial
interface.
The historical data may be stored in a flash ROM,
compact flash card, or collected in a
remote host PC for evaluation and print out.
The unit‘s compact size saves space and
requires less than 7" behind a panel.
13. Pyrometer is a non-contacting device that intercepts and measures
thermal radiation. This measure is used to determine temperature, often of
the object's surface.
This lab deals with instruments related to temperature.
(i) Thermocouple (iii) Thermistors &
(ii) RTD (iv) Optical pyrometery.
To measure the temperature at the center of furnace or any non-
approachable places, a long RTD or thermocouple is required.
Temperature calibration instruments are used for calibrating RTD,
thermocouple, etc. with the help of simulator.
Simulator is a signal measurement & feeding instrument.
Thermocouple used in NTPC is ‘K’ type.
(2) PYROMETERY LAB: -
14. INTERLOCK & PROTECTION ARE USED FOR SAFE START UP / OPERATION /
SHUTDOWN / TRIP OF ANY EQUIPMENT OR AUXILLARY EXAMPLES.
In this we can use relays, C.B.s, etc for the protection of the plant.
(a) Relays: -
A relay is an electrical switch that opens and closes under the control of
another electrical circuit. In the original form, the switch is operated by an electromagnet
to open or close one or many sets of contacts.
Because a relay is able to control an output circuit of higher power than the input circuit,
it can be considered to be, in a broad sense, a form of an electrical amplifier.
To perform time delay functions. Relays can be modified to delay opening or delay
closing a set of contacts.
Before vacuum tubes and transistors, relays were used as logical elements in digital
computers.
(3) PROTECTION & INTERLOCKS: -
15. To control a high-voltage circuit with a low-voltage signal, as in some types of
modems or audio amplifiers.
To control a high-current circuit with a low-current signal, as in the starter
solenoid of an automobile.
To detect and isolate faults on transmission and distribution lines by opening
and closing circuit breakers (protection relays).
Because relays are much more resistant than semiconductors to nuclear
radiation, they are widely used in safety-critical logic, such as the control panels
of radioactive waste-handling machinery.
(b) CIRCUIT BREAKERS: -
C.B. is an automatically-operated electrical switch designed to protect an
electrical circuit
Relays are used……
16. They are made in varying sizes, from small devices that protect an individual
household appliance up to large switchgear designed to protect high voltage
circuits feeding an entire city.
High-voltage breakers are broadly classified by the medium used to extinguish
the arc.
(i) Oil-filled (dead tank and live tank)
(ii) Oil-filled, minimum oil volume
(iii) Air blast
(iv) SF6
(v) Vacuum circuit breaker (manufacturing in ABB, AREVA, Siemens,
Circuit Breakers…….
17. CONDUCTIVITY , pH , SILICA , DISOLVED OXYGEN ETC. ARE MEASURED.
TO ENSURE QUALITY OF D M WATER TO BOILER.
TO PREVENT COROSSION.
TO REMOVE IMPURITIES TO PREVENT SCALE DEPOSIT IN THE BOILER TUBE.
TO PREVENT SILICA DEPOSIT ON THE BLADES OF TURBINE.
(4) WATER TREATMENT PLANT: -
19. THIS SYSTEM PROVIDES INCREASE IN SAFETY & RELIABILITY OF FURNACE.
PROTECTION FROM IMPOLLUTION & EXPLOTION.
FURNACE PURGE SUPERVISION.
HIGH ENERGY ARC IGNITOR CONTROL.
PULVERISER & FEEDER CONTROL / SUPERVISION.
FLAME SCANNER INTELLIGENCE.
↬ ACTUATORS: -
Actuators are devices used to produce action or motion.
The input is generally electrical signal and output is linear or rotary motion.
Electrical signal can be low power or high power.
Actuation can be from few microns to few meters.
Types of actuators :
(i) Hydraulic actuator. (iii) Manually actuator.
(ii) Pneumatic actuator. (iv) Motorized actuator .
The hydraulic & pneumatic actuators can be explain below as they
are used in
(5) FURNACE SAFETY SUPERVISION
SYSTEM: -
20. TYPES OF ACTUATORSTYPES OF ACTUATORS
HYDRAULICHYDRAULIC
It uses oil pressure signal.It uses oil pressure signal.
Widely used in power plants, oil refineries, petrochemical industries, steel plants, etc.Widely used in power plants, oil refineries, petrochemical industries, steel plants, etc.
Costly than pneumatic actuators.Costly than pneumatic actuators.
Requires more space for installation.Requires more space for installation.
Requires periodic maintenance.Requires periodic maintenance.
Used, where high power & fast operating response is required.Used, where high power & fast operating response is required.
Maintenance cost is high.Maintenance cost is high.
21. TYPES OF ACTUATORSTYPES OF ACTUATORS
PNEUMATICPNEUMATIC
It uses the pressure of gas or air in a pipe.It uses the pressure of gas or air in a pipe.
Widely used in industrial application process control, industrial instrumentation, powerWidely used in industrial application process control, industrial instrumentation, power
plants & domestic services.plants & domestic services.
Cheaper than hydraulic actuators.Cheaper than hydraulic actuators.
Requires less space for installation.Requires less space for installation.
Requires less maintenance.Requires less maintenance.
Used in hazardous installations where transmission lags are small & in small plants also.Used in hazardous installations where transmission lags are small & in small plants also.
As arrangement is quite simple , over-all maintenance cost is low.As arrangement is quite simple , over-all maintenance cost is low.
22. TSSS can be done by various methods: -
(i) TURBINE GOVERNING SYSTEM.
(ii) TURBINE STRESS CONTROL SYSTEM.
(iii) HP/LP BYPASS CONTROL SYSTEM.
(iv) AUTOMATIC TURBINE RUNUP SYSTEM ( ATRS).
(v) TURBINE SUPERVISORY SYSTEM.
↬ AUTOMATIC TURBINE RUNUP SYSTEM (ATRS): -
AUTOMATIC STARTUP/ SHUT DOWN SEQUENCE.
STRESS /TEMPRETURE MARGIN CONTROL ACCELERATION.
STRESS/TEMPRETURE MARGIN CONTROLLED LOADING/UNLOADING.
AUTOMATIC SYNCHRONISATION AND LOADING.
UNLOADING & SHUTDOWN OF MACHINE.
(6) TURBINE SAFETY SUPERVISION
SYSTEM: -
23. TSSS can be done to control the various problems:-
(a) BEARING VIBRATION.
(b) SHAFT VIBRATION.
(c) DIFF EXPANTION OF ROTOR AND CYLINDER FOR HPT/IPT/LPT.
(d) OVERALL EXPANTION OF HPT/IPT.
(e) AXIAL SHIFT OF ROTOR.
(f) TURBINE SPEED.
(g) EMERGENCY STOP & CONTROL VALVE POSITION.
(h) BEARING TEMPERATURE OF TURBINE.
TURBINE SUPERVISORY SYSTEM: -
24. It undertakes the calibration & testing of various annunciation cards.
It houses various types of analytical instruments like oscilloscope, integrated circuits,
annunciation cards, auto analyzers, switch gears, etc.
↬ Annunciation cards: -
Used to keep any parameter like temperature, pressure, level, etc. within limits.
It gets a signal when the parameter goes beyond limits.
It has a switching transistor connected to a relay that helps in alerting the UCB.
The different reading instead of being fed to the hard wired circuitry is fed to the
microprocessor controlled recorders.
↬ Switch-gears: -
It includes isolators, switching
isolators, circuit breakers, etc.
Comparison of the oil, air & SF6 C.B
is given here: -
(7) ELECTRONICS LAB: -
Various
terms
OIL C.B AIR C.B SF6 C.B
Rated voltage 6.6 KV 12 KV -
Rated
Current
1250 amp 1600 amp 1250 amp
Frequency 50 Hz 50 Hz 50 Hz
Breaking
current
34.7 kA 40 kA -
Making
current
110 kA 110 kA Symmetrical-
40kA
Assymmetric
al-43.5 kA
Gas pressure - - 2.5 bar
25. Automation is basically the delegation of human control function to technical
equipment for…..
• Increasing Productivity
• Increasing Quality
• High Speed Of Operation
• Reducing Cost
• Increasing Safety in working conditions
Considered mainly the following terms: -
(i) Automatic control system.
(ii) Deaerator pressure & level control system.
↬ (i) AUTOMATIC CONTROL SYSTEM: -
It is a preset closed-loop control system that requires no operator action.
i.e. the process remains in the normal range for the control system.
It has two process variables associated with it:
(a) a controlled variable & (b) a manipulated variable.
(8) AUTOMATION LAB: -
26. In automatic control system, the four basic functions that occurs are:
(i) Measurement, (ii) Comparison, (iii) Computation & (iv) Correction.
↬ Three functional elements needed to perform the functions of an automatic
control system are: -
(a) A measurement element.
(b) An error detection element. & (c) A final control element.
Continue……
The level transmitter measures the
level within the tank.
The transmitter sends a signal representing the tank level to
the level control device, where it is compared to a
desired tank level.
The level control device then computes how
far to open the supply valve.
To correct any difference between actual and desired
tank levels, level control device can do correction.
(i) Stage-I
(ii) Stage-
II
(iii)
(iv
)