Mart Gloudemans. Challenges in Ultrasonic Flare · PDF file · 2014-04-04Gas flow...

1

FLOWSIC100 Flare WIB Meeting, 04/2011 CEESI Flow Measurement Workshop 2014

FLOWSIC100 Flare – Challenges in Ultrasonic Flare meter field installations Mart Gloudemans, Sebastian Stoof, Sven Holzbächer SICK Germany


History of Evolution

2


SICK FLOWSIC100 has track record in flare metering since 10 years

Introduction

FLOWSIC100 Flare WIB Meeting, 04/2011 CEESI Flow Measurement Workshop 2014 5

Identifying flare gas measurements

•! Novy Urengoi •! Gas flow measurement at Oil processing

plant •! Ultrasonic flow meter FLOWSIC 600 •! Typical measurement range 0.3 .. 40 m/s •! Meter is out of work

3


Possible reasons: •! Dirty transducers •! High liquid contents •! Noise disturbance •! Electronic or Sensor faults



Reason for meter malfunction: •! Typical flare gas application •! Associated petroleum gas •! Velocity of gas approx. 85 m/s •! Blowing away effect


4


:! Waste gas from chemical and petrochemical processes

:! Associated Petroleum Gas from oil exploration

What is flare gas?

Flare gas – the unavoidable by-product



Unit A Unit B

Factory IIFactory 1

FT_Q

Challenge: Process waste gases are not emitted directly into the atmosphere.

•! Typical velocity of gas 0.03 .. 1 m/s at ambient pressure

•! Molecular weight is important for leakage detection and process control

•! 95% of process working time velocities < 1 m/s

•! Varying gas composition

5



System depressurizing in emergency situations

•! Significant amounts of gas leads to velocities up to 100 m/s

•! Requirement for avoiding pressure drops

•! High pressure condition

•! Pipe sizes 8“ .. 72“ (200 .. 1800 mm)


For emission and CO2 reduction many countries have been defining regulations and standards

•! Annually volume of CO2 certificates emitted by flaring: 370 Mio !

•! APG flaring causes 1.2% of total global CO2

emission •! Russian Government Decree No.344 with

emission fee for flaring of APG

•! Global trend to flare gas recovery

•! There are anti-flaring legislations with defined legal flaring limits + escalating penalties in most countries.

Emission trading of CO2 certificates

COMMISSION DECISION of EG/589/2007

Flare gas measurement – Quo vadis?

6


Flare gas measurement – Quo vadis?

For economic and environmental reasons:

:! Recovery of flare gas becomes increasingly important.

:! Various technologies for flare gas recovery available

:! Taxes and fees for flaring of hydrocarbons are raising all over the world

:! CO2 is going to be the most important value for GHG measurements

:! Raising world energy prices makes flaring uneconomical.

19


:! Calculation of CO2 emissions for compliance with government regulations.

:! Monitoring of abnormal process changes.

:! Reduction of gas wastage.

:! Process optimization and accurate mass balance calculation.

:! Optimization of steam usage.

Purpose of flare gas measurement

7


•! Gas velocity 0.03 .. 120 m/s

•! Extraordinary low flow performance required

•! No pressure drop allowed

•! Contamination by liquids and pollutions

•! Strong variation of gas mixtures

•! Harsh ambient conditions

Challenge of flare gas measurement

Turn-down ratio 4000 : 1


1.! Low flow performance To fulfill process optimization task and identification of valve leakage

Requirements on the flaregas measurement

2.! High flow measurement Availability of measurement in shutdown conditions.

3.! Measurement availability in “difficult” gas compositions Light + heavy gas. Sound absorbing gas.

4.! Adapted installation capabilities Long-term plant operation. Limited accessibility to piping. (Extraction Tools) Offshore installation.

Challenges of flaregas metering – The measurements companies view

8


:! Very unstable flow conditions + backflow.

Challenge 1: “Low Flow” condition < 1 m/s

:! Strong reduced measuring effect –

smallest transit time difference.

:! Thermal stratifications.

Extreme stability requirements

Operation in low flow conditions


1.! Time resolution

:! System +/-5ns in practise conditions

SICK transducer technology

2.! Measurement stability, ensured by:

:! Precise transducer signals

:! “Broadband” system

:! Highly accurate signal algorithm

:! Highly stable elctronics

3.! Special verification procedure for zero point stability


9


SICK Performance verification using special zero flow check


Trend VOG [m/s]

-0,001

-0,0005

0

0,0005

0,001

0 50 100 150 200

Time [s]

Zero flow stability of 0.6 mm/s


:! Several local regulations recommends a meter performance check every year

Field verification procedure needed

:! Field test box:

-! On-site capable

-! Zero point adjustment

-! Factory standard

SICK field verification of meter


10


:! Closed box with minimal influence of temperature and fluctuations

SICK field verification of meter


:! Data acquisition and evaluation with FLOWSIC FAD tool


:! Signal is „blown away“, received signal amplitudes

are reduced

:! Signal beam – an optimization task

-!Wider signal beam angle distributes energy over a

larger area

-! Small signal beam might not hit the receiving

sensor

“High Flow” condition 100 m/s or more

:! Disturbing noise in the pipeline and at the sensor

Limited Signal Noise Ratio (SNR)

Challenge 2: Operation in high flow conditions

11


Investigations in Signal Noise Ratio (SNR)

Noise Level undisturbed flow 80 kHzp ambient

0

50

100

150

200

250

300

0 10 20 30 40 50 60 70 80 90 100 110 120

VOG [m/s]

Rec

eivi

ng A

mpl

itude

[dig

it]

Sensor B

Sensor A

The sensor inside the gas flow becomes to a significant source of noise !

Operation in high flow conditions


Aerodynamic probe design

•! Probe design with ultrasonic sensor embedded in an aerodynamic shape

•! Noise reduction at sensor – Significant improvement of Signal Noise Ratio (SNR)

•! Path angle of 75°


12


:! Probe design with ultrasonic sensor embedded in an aerodynamic shape

A

B

SICK innovative high speed sensor design

:! Noise reduction at sensor – Significant improvement of Signal Noise Ratio (SNR)



:! Short term changes possible.

Challenge 3: Gas composition

:! Difficult compositions can reduce SNR by a changed transmission

characteristics of transducers.

Considerations for gas composition

Light gas

SOS ~700 m/s

Sound beam lobe

Heavy gas

SOS ~280 m/s

Natural gas

SOS ~400 m/s

13


SICK transducers + signal algorithm

SOS 934 m/s, MW 3.5 g/mol, ~90%H2, 10% CH4

SOS 611 m/s, MW 7.8 g/mol, ~60%, 40% CH4

SOS 349 m/s, MW 23 g/mol

:! Transducers with large bandwidth and amplitudes ! gas composition do not have a significant effect on signal performance.

:! SICK Flare measurement starting at compositions with MW 2 g/mol.

Considerations for gas composition


2-path configuration

:! Much less sensitive for flow profile deformations at instable flow conditions

:! 2-path meter can reduce uncertainty down to 1 %

Meter installation requirements

14


Optional 2-path configuration :! For higher accuracy demands. :! For representative measurement results also under difficult measuring conditions

(disturbed flow, gas composition).



Gas with liquids and pollutions

:! Use of high power version FLOWSIC100 Flare EX-RE


15


1.! Device without meter body :! Hot tapping installation

:! Nozzle installation tool / geometry calculator

:! 1- or 2-path configuration


Solutions: Flowmeter with and without meter body

2.! Device with meter body :! System solution - plug&play

:! Factory-sided parameterization - ready for operation

:! Solution for higher uncertainty demands by optional:

:! Highly precise 3D survey

:! Flow calibration for uncertainty down to 0.5%


!! < +/- 0.1 mm

Meter body

3D survey - Minimizing geometric uncertainty


16


:! Calibration on SICK test stand, approved and traceable to national standard, represented by the german PTB (Physikalisch Technische Bundesanstalt, Germany).

:! Test benches is equipped with two electric fans with a total connected power of 70 kW.

Measurement range 30 ! 13000 m"/h

Optional flow calibration



Offshore installations :! Highly robust device configuration with electronics housings in stainless steel :! Highly durable material configurations in Duplex or Hastelloy :! Special paintings


17


Business opportunities

Example Offshore platform Norway

•! Mass flow: ~ 165.844 t/year •! Emission: ~ 500.000t CO2/year

CO2 tax Norway: 21$ /CO2 t (15!/ CO2 t) Costs CO2 Emission total: 7.5 Mio !/year 1% accuracy increase: 75.000 !/year per plant

Case Mass flow Annually

Min 160 t/h 95%

Normal 290 t/h 3%

Max 504 t/h 2%

Total amounts:


FLOWSIC100 Flare – solutions

18


Optional 3x1path configuration :! System solution to serve 3 different flare measurements with a single control unit.

Flare 1

Flare 3

Flare 2



Remote installation of control unit up to 1,000 m (3,000 ft) from measurement location


:! Installation of control unit in safe area.

:! Safe costs of an expensive installation in hazardous area.

19


Single-sided installation :!Use of “probe version” FLOWSIC100 EX-PR

up to 1,000 m

Control unit non-ex or Ex-Zone 1 and 2 (ATEX), Cl I, Div2 (CSA)

Safe or hazardous area



FLOWSIC100 EX-S FLOWSIC100 EX FLOWSIC100 EX-PR -! „Standard“ cross-duct - Retractable - ATEX Zone 1+2 -! CSA Cl I, Div.1/2 -! IEC Ex Ga/Gb Ex d [ia] IIC T4

-! „High power“ cross-duct - Retractable - ATEX Zone 1+2 -! CSA Cl I, Div.1/2 -! IEC Ex Ex d IIC T4

-! Probe version - Retractable - ATEX Zone 1+2 -! CSA Cl I, Div.1/2 -! IEC Ex Ga/Gb Ex d [ia] IIC T4

FLOWSIC100 Flare – Operation principle & devices

20


:! Medium housing -! non-ex

-! ATEX Ex zone 2

-! CSA Cl I, Div2 / zone 2

-! up to 3 measurement points -! optional conduit connection

:! Flameproof housing

-! ATEX Ex zone 1 -! up to 3 measurement points

-! optional conduit connection

Multi Control Unit MCUP

FLOWSIC100 Flare – Operation principle & devices


Conclusion

21


Conclusion

:! Leading transducer technology

•! Best signal performance, shortest time resolution for reliable and precise measurement also in difficult gas conditions.

•! Cross-duct measurement up 72” pipe size.

Trend VOG [m/s]

-0,001

-0,0005

0

0,0005

0,001

0 50 100 150 200

Time [s]

:! Unique zero flow performance verified by special Zero Flow Test procedure.

•! Fast and reliable process control + optimization.

:! Innovative high speed sensor design

•! High measurement availability also in “High flow” conditions up to 120 m/s.


:! Installation advantages:

•! 1x1, 2x2 or 3x1 path configuration

•! Remote installation of control unit up to 1,000 m from measurement location Installation in safe area safes costs of an expensive installation in hazardous area.

•! Probe version for single flange mounting Single nozzle installation for pipes with access from one side only. Lowest installation expenditure.

Conclusion

22



:! Thank you for your attention.

Date post:	10-Mar-2018
Category:	Documents
Upload:	dodan
View:	213 times
Download:	1 times

Mart Gloudemans. Challenges in Ultrasonic Flare · PDF file · 2014-04-04Gas flow...

Documents