boiler instrumentation.ppt

8/13/2019 Boiler Instrumentation.ppt

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23 December 2013 PMI Revision 00 2

Presentation outline

Basic Process Measurement

Level Measurement

Flow MeasurementTemp Measurement

Steam Generator C&I system


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CONTROLSINSTRUMENTATION Control & Instrumentation deals with various

measurement, indication, transmission and controlin different technical fields.

Instrumentation is for measurement of variousparameters.

And controlling various parameters from a remotecontrol room.


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Instruments Instruments for measuring various physical quantities like

Pressure Temperature

Level

Flow

Turbovisory Vibration

Speed etc.

Analytical

PH

Conductivity Silica etc


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Instruments Measuring Electrical parameters such as

Load

MVAR

Frequency

Voltage

Current etc. Indicators

Local

Remote

Recorders Single Point

Multipoint

Continuous

Dotted


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Pressure Measurement Manometers for low pressure.

Water filled

Mercury Filled Bellows for medium pressure

Bourdon tube gauges for medium and high

pressure measurements


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Pressure Measurement Transducers of different type for all ranges for telemetering

purpose.

Capacitive type.

LVDT type. Strain gauge type.

Mode of connection of Transmitters

Four Wire

Two Wire


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Type of Transmitter Microprocessor based 2 wire type,. 2. Sensor Type Capacitance/Piezo-electric

3. Accuracy 0.1% of span

4. Output signal range 4-20 mA DC (Analog) 5. Turn down ratio 30:1

Zero and span drift 0.015% per deg.C at max span a and

0.11% per deg.C at min. span.


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Level Measurement Floats and liquid displacers

Head pressure measurement

DP type

Ultrasonic

Direct Viewing

Strain gauge


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Level Measurement In closed pressurised vessels, Differential pressure measurement

is used to measure the level.

One side condensate pot is used where constant level ismaintained.

Other side is connected to the bottom of the vessel. Difference between these two heads gives the level.


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Level Measurement (ClosedVessel)


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Level Measurement (ClosedVessel)


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FLOW MEASUREMENT Controlling the flow rate of fluids is a key control

mechanism for any process plant.

There are many different types of devices available

to measure flow.


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Flow Measurement HEAD TYPE

Orifice Plate

Rotameters

Venturi Tubes Target Meters

VELOCITY TYPE

Magnetic

Vortex DISPLACEMENT

Turbine Meter


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HEAD TYPE Head type devices measure flow by constricting a

stream and measuring the resulting pressure drop.

The pressure drop can then be related to a flow.


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Orifice Plates An orifice plate is a very simple device installed in a

straight run of pipe.

The orifice plate contains a hole smaller than the

pipe diameter.

The flow constricts, experiences a pressure drop,

and then the differential pressure can be related to

a flow.


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Orifice Plates


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Rotameters Rather than using a constant restriction area and a variable

pressure differential, rotometers use a variable restrictionand a constant pressure differential to measure flow.

Typically, rotometers are used to measure smaller flows and

the reading is usually done locally, although transmission ofthe readings is possible.


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Rotameters The rotometer consists of a float that moves vertically through a slightly

tapered tube.

As fluid enters the bottom of the rotometer, the float is forced upwarduntil the force is balanced by gravitational forces.

Most rotometers are made of glass with markings on the outside so thatflow readings can be taken visually.

The advantage to rotometers is the simplicity of the device and aconstant pressure drop.

Also, rotometers do not require straight pipe runs for installation so theycan be installed just about anywhere.


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Rotameters


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Venturi Tubes A venturi tube also measures flow rates by constricting fluids and

measuring a differential pressure drop.

Venturi tubes allow for flow measurement with lower head losses

than orifice plates.


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Target eters A target flowmeter operates just as the name implies.

A small "bullseye" is placed inside the pipe and is connectedto a pneumatic transmitter.

Typical applications include flow measurement of steam andoutdoor liquids.

In a target flowmeter, the square of the force exerted on thetarget is proportional to the volume or mass flow through thepipe.


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Target eters


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Flow measurement Differential pressure flow meters

Orifice pattern

Venture & nozzle pattern

Pitot tube pattern

Dall tube pattern Variable area flow meters

Displacement and interferential

flow meters

Electromagnetic flow meters.

Ultrasonic Flow meters

Orifice plate is a circular metal plate witha center hole.

In venture tube there is a gradual changein the area.

Nozzle is similar to a orifice but with acurved form of approach


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Temperature Measurement Expansion of Solids

Thermostats

Expansion of Liquids Temperature Gauges

Expansion of gases

Temperature Gauges Thermal Electricity Thermocouples

Type K Chromel Alumel etc.

Change of Electric Resistance (RTD) Pt100

Cu53

Intensity of total radiation Optical Pyrometer

Radiation Pyrometer


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Temperature Measurement Expansion of Liquids and gases are used for local

gauges.

Thermocouples and RTDs are used for most of theremote temperature measurements and controls.

RTDs are used for low temperature applications.

Pyrometers are used for high temperaturemeasurements. (NON Contact type).


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Temperature Measurement (a) Type of Thermocouple 16 AWG wire of

chromel-Alumel (Type K) or 24 AWG wire Pt-

Rhodium Pt (Type R); ungrounded type depending

on operating temperature range.

(b) Type of RTD 3/4 wire - Pt RTD 100 ohm

(as per DIN-43760)


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Temperature Measurement C J C Boxes

a) Ref. temp. 60C 1.3 C for

Thermocouple

b) Effect of ambient temp. 0.1% per 10Cvariation

c) Material 4 mm thick fibre glass reinforced polyster

d) Protection class of IP 55


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Temperature Measurement Outlput signals: Analog : 4-20 mA DC

Binary : 2 NO + 2 NC for

high alarm

2. Zero & span Adjustment : Available 3. Ambient temp. : 60C

4. Indication : Digital

5. Enclosure Type/Material : Weather &

Dust proof (IP 55) Die cast Aluminium/SS


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SG RELATED CONTROL &

INSTRUMENTATION SYSTEM/EQUIPMENTS FLAME MONITORING SYSTEM

COAL FEEDERS CONTROL AND INSTRUMENTATION

ELECTROMATIC SAFETY VALVES

FURNACE TEMPERATURE PROBES

ACCOUSTIC PYROMETERS

BOILER FLAME ANALYSING SYSTEM (IN LATEST

ADVANCE BOILER )


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SG RELATED CONTROL &

INSTRUMENTATION SYSTEM/EQUIPMENTS

COAL BUNKER LEVEL MONITORING SYSTEM

ELECTRONIC REMOTE DRUM LEVELMONITORING SYSTEM(Hydra step)

CONDUCTIVITY TYPE LEVEL SWITCHINGSYSTEM

ASLD SYSTEM

APH FIRE SENSING


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THANK YOU

boiler instrumentation.ppt

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