4 flow computer

7/27/2019 4 Flow Computer

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Gurwinder Kamboz

01 June 2013

Flow computersNew Technology Flow Measurement


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Flow computersAgenda

Gurwinder Kamboz01 June 2013

1. History & Development

2. Accuracy & Reliability

3. Meter functions

4. Technology & Communication


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3. Meter functions





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History & Development

Technology

| 01-06-20134 Flow computer measurement


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Communication Telegraph cable (1843) replaced Pony express

Whistle of steam engine

Wireless radio (Marconi, 1894)



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Communication



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Communication



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1900s flow correction

1886: Uncorrected

Westinghouse meter with local totalisers

No correction



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1916: Manually corrected

Orifice strip chart recorder

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1922: Manually corrected

Traditional slide ruler



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1939: Mechanical correction

Flow integrator borden



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1955: Mechanical correction

Local totaliser with P & Tcorrection for gas turbine



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1960: Analogue correction

Analogue computer



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1979: Digital computers

General purpose process computers

Redundant dual Orifice meter run FC withsupervisory



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1982: Flow computers

Installed in control room

P, T correction, variable Z, 5000 Hz pulse, external Pand T, mains powered, printer output

1985: Flow correctors

Installed at meter

P, T correction, factory Fixed Z, 0.5 Hz pulse,integrated P and T, battery powered, no serial



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1990s flow computersField mounted

Check or allocation, 0.2% or better, (solar)powered, external P & T, high frequency pulses,optional GC input

Panel mounted

High pressure, 0.1% or better, mains powered,external P & T, high frequency pulses, GC input



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1980 2000s flow computers

Did the job

Boring interface

No real human interaction Restricted to move with the times

No real network capabilities

Simple and dumb

No alternative



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Window dressing

Old flow computers upgrades

The basic design stays the same

A modern processor is used to disguise the upgrade The rest of the same hardware cannot keep up

Processor runs at very low speed

No real benefit in terms of I/O measurement

No improvement on communication speeds

No impact on calculation speeds

Accuracy still the same!



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Then vs now

Almost all corrections based on limited database

New corrections now based on extended database

New corrections based on physical properties Examples: New GERG, Shell wet gas correction

Most are processor intensive like AGA 10

With multiple runs, fast processing needed

Incorporate redundancy in communication and accuracy



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3. Meter functions





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Accuracy & Reliability

DefinitionsAccuracy

The degree of closeness of measurements of a quantity to thatquantity's actual (true) value

The comparison of a measurement with a known standard, usedto determine whether the measurement is reliable.

The difference between a measurement reading and the truevalue of that measurement.

Is this the correct use?

Are we using it in the appropriate manner?



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DefinitionsUncertainty

The risk of miss-measurement

Scepticism of all quantities measured, and calculate

Expressed as a +/- value Component level

System level

Cannot be eliminated

Bias

Mis-measurement

Caused by equipment malfunction and/or human error


+/- 0.025%

+/- 0.001%

+/- 0.2 V

+/- 0.5 V

Accuracy or uncertainty?


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DefinitionsPrecision

Also referred to as repeatability

Repeating the same results with the same equipment

Also referred to as reproducibility

Producing the same results with different equipment

The degree to which an instrument will repeat and reproduce thesame measurement over a period of time.

Resolutions

Also known as sensitivity

The smallest change in a measured value that the instrument candetect



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DefinitionsError

The amount of deviation from a standard or specification usuallyeliminated in the measuring process.

Stability

The ability of a measuring instrument to retain its calibration over along period of time. Stability determines an instrument'sconsistency over time.

The degree to which a series of supposedly identical

measurements remains constant over time



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Overview 20th

century

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1900 1925 1950 1975 2000

Uncorrected Manual Mechanical Analog Digital

0.5% 0.3% 0.1%1%Accuracy:



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Basic accuracy improvement

Analogue signals

In 1900s A/D convertor was expensive

American suppliers typically used 12 bits A/D conversion European used 16 bits resolution

Today 20 bit A/D conversion is norm

256x more resolution than 12 bits 1,000,000 instead of 4,000 steps



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Basic accuracy improvementHow to eliminate uncertainty

Digital signals Full digital HART communication No temperature effect by flow computer No errors introduced by barriers or A/D conversion

Cycle time determines accuracy

In 1900s limited due processing speed

Cycle time varied processor dependent

Calculations & measurements performed

Serial communication Number of runs Complexity of system/skid integration

Now a sec cycle time can be guaranteed

Dedicated CPU processors on I/O boards32 | 01-06-2013 Flow computer measurement


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Basic accuracy improvement Time accuracy is critical part of measurement

In PCs often many seconds a day off

Flow computers used same chips

Improved time measurement with new flow computers

Dual chronometry/pulse interpolation during proving

Pulses interrupted a processor for measurement This was very slow, inaccurate

Measurement performed at hardware level

Accuracy and precision well below +/- 0.001%



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Basic accuracy improvement

Level A dual pulse integrity assumes correction

Missing pulse Spurious pulse

EMC pulse both wires

Limited due to lack of processing power

Pulse handling at programmable hardware level

All level A problems are corrected

More accurate due to more frequent measurement & inturncalculations

Calculation accuracy

US often 32 bit, single precision floating point Europe 64 bit, double precision floating point



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Basic reliability improvementSelf checking for correct operation:

Memory Data corruption Communications I/O boards

Build-in hard and software verification

Serial number per board Checksum for application and data

Checking of meter and transmitter operation

API level A blade failure detection Ultrasonic sensor operation using AGA 10 VOS P and T operation.



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1. History & Development2. Accuracy & Reliability

3. Meter functions



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Meter functions

Performance Linear correction

Corrections for the effect of flow rates (min and max) The factors/ errors in % obtained during calibration of a meter

which are the corrections needed to linearize the meter. Each flow rate a different error is used. In between the given flow

rates a linear interpolation is used This is expressed by a variation of the K-factor over the specified

flow range. So for each flow rate a different K-factor is used

K-factor curve

The meter will generate a specific number of pulses for every unit

of product passing through it Curve corrects meters non-linearity Viscosity of fluid effects curve Number of pulses per unit volume

Output frequency is proportional to flow38 | 01-06-2013 Flow computer measurement


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Meter functions

Performance

Meter Factor (MF)

Obtained by proving Set at standard conditions

Meter corrected against prover volume at ambient conditions(T&P)

Other parameters

Scaling factors Low & high flow rates

Frequency set points

What else?



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Meter functions

Maintenance Early warning by additional diagnostics

Allow full remote access to flow computer

With high level functions graphics more important

Real-time & historical trending

Calibration: P & T stabilisation PID tuning Troubleshooting Backtracking

Bar-graphs

Diagnostics Tank levels



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Meter functions

Diagnostics



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Meter functions

Diagnostics



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Meter functions

DiagnosticsUFM built-in diagnostics



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Meter functions

DiagnosticsThe ability to see the performance of field instruments



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Meter functions

Diagnostics

Diagnostic = health

Overall measurement accuracy

Measurement uncertainty is a function of:

Selection of appropriate metering device

Correct installation of metering device

Correct meter operation & processing of metering information

Proper maintenance of the metering device

Schedule maintenance over longer periods Correctly identify faults



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Meter functions

Increasing accuracyFlow computer is as important as flow meter

Accountability between buyer & seller

Accountability for taxation

Flow meter + flow computer accuracy can save millions $

Accuracy is critical !

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Existing Russian contract prices to most European countries ranged from $110 to $280 per cubic meter, used 150



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1. History & Development2. Accuracy & Reliability

3. Meter functions



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Technology & Communication

Interface & usability

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Density TemperaturePressure

Flow rateuncorrected

Gas composition

Single & multi stream applications



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Metering station Sampler Prover/master meter Valves

Single & multi stream applications



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Field instrument inputs

Correct flow rates, measurements& calculations

DATA



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Interface & usability Touch screen

Visual rather text based

Custom screens User defined menu structure

Colour graphical display State of the art flow computer

Supervisory like functions

Modbus mapping

Multi medium applications

Mix of liquid, and gas in 1 unit Mix of Metric and US Customary Mix of different metering technology

Seeing data the way you want to see it

Matching your expectations with consumer technology



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Interface & usability 5 Streams + prover/Master meter

Multilingual displays

Fast processing speed second

Dedicated CPU for each I/O board

SD card for data logging & storage

Fully digital

Flexible & open

Future proof

Fully configurable with easy to use GUI

Advance useful technology features



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Remote Access

Website

Same look and feel

Read only security Any smart device:

Iphone Ipad

Tablet Android

PC


http://www.summit8800.com/http://www.summit8800.com/http://www.summit8800.com/http://www.summit8800.com/


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Interface & usability Take over front panel

Change parameters

Download alarms & audit log

Provide diagnostic graphics

Save configuration centrally

Ability to determine the flow process

Activate commands for field devices (proving)

Communication for centralised maintenance

Access by specialists in central office

Reduce travel time & quick and efficient response

Billing & accounts

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Summit 8800

Summit 8800

NETWORK



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Interface & usabilityA picture is worth a thousand words

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1985 1990 1999



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Interface & usability Measurement is how we read data

How quickly we understand what we areseeing

How easily we can interpret the values

How quick the measurements are beingupdated

How quickly is the flow computer calculating

How accurate is the data being used

Are we doing everything possible to reduce

uncertainty

Are the field instruments at 100% operation



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Conclusion Fast time cycle

I/O measurement at hardware

Advance communication

Superior diagnostic

Excellent meter functionality

Customised operating Interface

Applying the correct useful technology

All contribute to increasing measurement accuracy& reducing uncertainty



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Thank your for your attentionNew Technology Flow Measurement


4 flow computer

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