Compressible Flow Through

Coriolis Meters

Thomas Kegel, CEESI

Wednesday Morning

Surrogate Fluid Calibration

• Water vs gaseous hydrocarbon

• Air vs gaseous hydrocarbon

• Secondary effects

– Velocity

– Pressure

– Mach number

– Compressibility

Objectives

• Gain operational knowledge

• Improve calibration processes

• Share results with industry

• Precedents

– Ultrasonic

– ISO 5167 compliant venturi

– Critical flow venturi

– Turbine

Three “Part” Program

• Literature Survey

• Massed calibration results, 46 meters

• Detailed testing, 2 meters

Round 1:

• May 2011 – Jan. 2014

Round 2:

• Aug. 2012 – Nov. 2104

Size [in] Quantity

0.25 3

0.5 19

1.0 12

2.0 10

3.0 2

Massed Calibration Results (Round 1)

• Grouped based on curve shape

• Deviation vs. mass flowrate (%FS)

• High flow = Groups A, B, C and D

• Low flow = Groups E and F

Typical High Flow Data

Typical Low Flow Data

ROUND 1

• Seven calibrations

• Curve fits in black (average)

• 95% confidence interval in red

Round 1 Group A

• Six calibrations

• Curve fits in black (average)

• 95% confidence interval in red

Round 1 Group B

Round 1 Groups A and B

±0.16%

ROUND 2

Re-organize the groups

Current Group A

±0.16%

Current Group B

±0.16%

±0.30%

Current Group C

Current Group D

Current Group D

±0.16%

AGA 11 Requirements

Low Flowrate

AGA 11 Requirements

Round 1 Random Effects

AGA 11 Limits

Round 2 Random Effects

Part 2 Test Meter

Part 2 Test Meter

Limits From

Part 1

Drive Gain Diagnostic

Drive Gain Diagnostic

Conclusions (Part 1, High Flow)

• Mass flowrate above 3%FS

• Meters meet the requirements of AGA 11 (95% CL)

• Variation with velocity:

– Increase in error with velocity

– 36 meters fit within ±0.16%

– 6 meters fit within ±0.30%

– 4 meters do not follow the trend

Conclusions (Part 1, Low Flow)

• Mass flowrate below 3%FS

• Meters meet the requirements of AGA 11 (95% CL)

• Variation with velocity:

– Increase in random variation with decreasing

flowrate

– Indication of zero shift

Conclusions (Part 2)

• Observed variation with pressure

• Apparent correlation with velocity

• Some similarity to Part 1

• Interesting correlation with gain variation

Future Plans

• Increase Part 1 to 75 meters

• Add third Part 2 meter

• Integrate more diagnostics

• Transient behavior

Thank You For Your Time