Flare Gas OVW

8/2/2019 Flare Gas OVW

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Wh Measure Flare Gas ?

,

and chemical plants are primarily installed for safety

purpose.

• Flare gas measurement systems are primarily installed

for:

A) Leak

detection

B) Mass balance

C) Environment

D) National

legislation

E) CO2 emission control




A) Leak detection:

• Detection of leakage from different processes into the main flare stack

.

• Monitoring of molecular weight for gas composition changes.

B) Mass balance:

• To measure the outlet to flare is important for the mass balance account.

• Detailed information of what has been extracted is essential for optimising

production.

C) Environment:

• The emission from flare stacks represent a source of pollution, both for CO2, soot, and dirt.

• Kyoto agreement

and

general

public

expectations

have

put

focus

on

the

impact o are gas emissions.

• Global restrictions and regulations on the pollution from the refineries, gas terminals and chemical plants.




D) National legislation:

• ore an more coun r es are ocuse on yo o agreemen .

• Operators imposed to report their emission to national government.

• On NCS

the

amount

to

flare

was

reduced

with

30%

from

1989

to

1993.

The law and metering requirements was implemented in 1991

E) CO2 tax:

• In more and more countries oil companies and operators are imposed

to pay tax for their CO2 emissions.

• CO2 tax has increased the focus on flare gas measurements in these

countries, resulting in considerable reduced flaring.

• Accurate monitoring

important.



There are basically four types of flowmeters available for

Flare applications:

• Ultrasonic Gas

• Thermal Mass

• Optical mass

• Doppler

• Annubar



Preffered Technology for Flare Gas

Measurement‐ ‐

– Operation principle: An ultrasonic time‐of ‐flight flow meter uses

the difference

of

up

‐and

downstream

transit

times

that

the

flowing

gas

causes

– Features:

• Causes no pressure drop

• oes not o struct t e process ow

• No mechanical

moving

parts

• High turn‐down ratio

• e ‐ agnost c capa t es

• High temperature range

•Fast

response

time

• Goo repeata i ity.

• Sensors can be replaced during operation

• Not dependent on gas quality



Flare Ultrasonic Meter GF868 ‐ GE

Measurement Solutions

Features

• Measures velocity, volumetric and mass flow• New standard velocity range to 100 m/s (328 ft/s)

standard• New

extended

velocity

range

to

120

m/s

* • Measures instantaneous average molecular

weight• Measures hydrocarbon gases• Minimal maintenance due to no moving

parts, no holes or tubes, and tolerance to

dirty or

wet

conditions

• Delivers accurate flow rate, independent of gas composition

•

• Field‐proven installation techniques• Built‐in totalizers• Built‐in power supply for pressure and

temperature transmitters

• 3940 to 1 turndown ratio• One‐ or two channel/path configurations• Velocity maximum may be higher in specific installations



Specifications for GF868



Flare Gas: Competition

•

–

High Maintenance:

•

transfer rate causing large errors or total failure

– Small Rangeability:•

Inability To

Measure

Low

Flow

Rates

• At low flow rates, 30 to 40 % error is very common

–

• Changes in MW, Viscosity, and Specific Heat ALL affect accuracy

– Liquid

Deposits:

• Evaporation of liquid on thermistor surface takes away heat causing erroneous errors




• Advantages About GE SENSING (Panametrics)

–

GE

Sensing

can

Handle

Wider

Flow

Range

– GE Sensing can Handle Wider Temperature Range

– GE Sensing

transducers

are

made

of

Titanium

to

withstand

the

most

extreme process conditions (high reliability!)

– GE Sensing GF868 offers several different types of analog and digital




•

– GE Sensing has the most experience with Flares Close to 5000

Flare Installations Worldwide!

– GE Sensing is the Industry Standard Texas &

– GE Sensing

Field

Service

Support

&

Experience

is

Far

Superior

Spanish‐speaking field engineers for the Latin American region




•

– GE Sensing Offers a Wide Range of Installation Configurations for

different pipe sizes

– GE Sensing Insertion Mechanism allows transducers to be removed

rom p pe w ou e nee o ave a s u own

–

operator to immediately identify meter performance and process

stability

Flare Gas OVW

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