installation effects on ultrasonic flow meters for liquids€¦ · installation effects on...

Installation Effects on Ultrasonic Flow

Meters for Liquids

Jan Drenthen - Krohne

Jan G. Drenthen &

Pico Brand

ALTOSONIC 5 Installation effects on ultrasonic flow meters for liquids

Jan G. Drenthen &

Pico Brand

1. Introduction

2. Meter design

3. Test results

• Installation effects

• Meter proving

4. Conclusions

ALTOSONIC V

First Ultrasonic liquid flow meter for custody transfer on the

market

In operation since 1997 In operation since 1998

3

ALTOSONIC V Even in harsh environments

4

Offshore Ambient -55°C

ALTOSONIC V … and in tough applications

5

Cryogenic High viscosities

Pico Brand

2014-04-01

1. Introduction

2. Development of the ALTOSONIC 5

3. Test results


• Meter proving

4. Conclusions

7

Accuracy depends on:

• Acoustic path configuration

• The number of paths

• The calculation schedule of individual paths

Major issues are:

• Erratic flow profile changes in the Transition region

• Profile distortions

• Temperature stability

Most manufacturers only state the accuracy for Reynolds >

8.000.

Multi-path Flow Meter Configuration

Osborne Reynolds dye

experiment.

8

What /who is Reynolds (1842 – 1912) ?

Flow transition from Laminar to Turbulent pipe flow.mp4

10

What is Reynolds?

Doing his experiments, Reynolds found that there is a similarity in the

flow pattern if it is characterized by a certain dimensionless number;

which he called the Reynolds number.

VD

..

Re

- density

V - mean velocity

D - internal pipe diameter

µ - the dynamic viscosity

For identical Reynolds numbers, the profiles are the same.

11

Calibrating at different viscosities than used in situ.

As Reynolds found, for identical Reynolds numbers, the profiles are the

same. Therefore during calibration at a different viscosity, not the

velocity range, but the Reynolds range is of importance!

Essential is to match the Reynolds number as they are encountered in

situ.

Reynold’s No. Water 1 cSt HC 5 cSt HC 10 cSt

25.000 0.1 m/s 0.5 m/s 1.0 m/s

50.000 0.2 m/s 1.0 m/s 2.0 m/s

250.000 1.0 m/s 5.0 m/s 10 .0 m/s

1.000.000 4.0 m/s

Example for a 12”meter

Low viscosity versus high viscosity

12

Low viscosity

High viscosity

The University of Queensland pitch drop experiment.

Picture taken in 1990, two years after the seventh

drop and 10 years before the eighth drop of bitumen

fell.

Bitumen

http://en.wikipedia.org/wiki/University_of_Queensland

Temperature dependence of crudes

| 2014-04-31 13 | ALTOSONIC for liquids

Within 20 degrees F (10 °C) , the viscosity changes

a factor 2

14

Impact of temperature

Especially highly viscous crude oils are transferred at high

temperatures; therefore temperature fluctuations are commonplace.

As a direct consequence of these temperature variations, large

variations in viscosity occur and as a result of that the flow velocity

profile will change constantly.

So at high viscosities, temperature stability is essential to get an

accurate measurement result.

At low viscosities, there is more turbulent mixing and temperatures play

a smaller role; but than installation effects are more apparent.

15

The reasons for using a reducer are:

• the improvement of the velocity profile in the transition range.

• reduction of the impact of the turbulence.

Designer’s toolbox: the reducer

Straight bore Reducer (β ratio 0.6 – 0.8)

Meter design

1. Using mathematics dating from the 1830’s (such as used in the Westinghouse patent from 1968 and still

applied in many parallel paths meters).

And / or…..

16

Gauss Jacobi Legendre Chebyshev

In selecting the acoustic path configuration there are 2 possibilities:

2. by applying flow research and using physical models such as CFD. Only then the

technology can progress.

17

Hydrodynamic models / CFD

Computational Fluid Dynamics (CFD)

Turbulence models (e.g. k-ε model, k-ω model)

5,897,875 elements

CPU time 15 hours (1 Core)

DN25

Double out of plane bend

Re=3250

18

Flow profile distortions

Reducer tests at the University of Erlangen

19

Laboratory tests

Reducer tests at the University of Erlangen

Laser Doppler and CFD calculation

20

-1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 10

0.5

1

1.5

r/R [-]

v/v

gem

[-]

Position x: 0R

Disturbed profile 5.5 D after a single 45° bendingmeasured in a 135° plane

Measured LDA

Theory (30% and 0.6R)

21

Analytical model

Theoretical models:

- Undisturbed fully developed pipe flow theory

- Mathematical hydrodynamic disturbance

functions

- Wall roughness theory

- Cavity correction theory

- Flow integration scheme

Input:

- Experimental LDA/PIV Data

- Geometrical parameters

- Hydrodynamic parameters

(e.g. Reynolds number)

Computation:

Path position optimization

Final design -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1

0

0.5

1

1.5

r/R [-]

v/v

gem

[-]

Position x: 0R

Disturbed profile 5.5 D after a single 45° bendingmeasured in a 135° plane

Measured LDA

Theory (30% and 0.6R)

22

Acoustic path configuration

Improving upon linearity and installation

effects starts with the optimization of the

sensor tube concept

To determine the best path position,

thousands of different path positions have

been simulated and tested.

Conclusion:

Measuring closer to the pipe wall

improves the measurement.

Improving ultrasonic performance by designing smaller transducers enabling measuring

closer to the wall

23

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

0 5 10 15 20

Lin

eari

ty

Number of paths

Current design

Linearity over 1e2<Re<1e8 p-p [%]

Improving ultrasonic performance by designing smaller transducers enabling measuring

closer to the wall

24

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

0 5 10 15 20

Lin

eari

ty

Number of paths

Current design

New design

Linearity over 1e2<Re<1e8 p-p [%]

7

Design process 7 path meter

25

-0.9-0.8 -0.55 0 0.55 0.8 0.9

7 beam configuration; search area per beam

Red dashed lines indicates the search boundaries

Fixed

11 22 33 44

Flow

computation

26.110

Profiles

Worst case

filter

1.960

solutions

Finding the optimum position

25

Results base lines 7 BEAM (TRAPIL RAW DATA, 20D no FC)

26

OIML & API requirements.

Next to the requirements for the accuracy, both the OIML and the API also state

requirements for the repeatability of the measurement.

OIML requirements:

• Maximum permissible error: 0.2%

• Maximum repeatability: 0.12%

This also impacts

‒ the path position

‒ the selection of the flow conditioner

‒ the sampling frequency

‒ the minimum proving volume when a small volume prover is used.

27 27

Meter design considerations

28

accuracy repeatability

Full bore L L

Reducer J J

Paths located close to the wall J L

Plate flow straightener J L

Tube bundle L J

28

Meter design conclusions:

The bore reduction has a dominant effect on the meter performance.

The best design, accuracy wise, is a meter with:

A reduced bore

Acoustic paths close to the wall

A plate flow conditioner

Therefore that design is used for the full range Altosonic 5.

29 29

ALTOSONIC 5

Path configuration

7 direct measuring paths in a criss-cross configuration and one vertical

diagnostic path 30

Artist impression of the new meter.

31 31

Jan G. Drenthen &

Pico Brand

1. Introduction


3. Test results


4. Conclusions

Installation tests

The goal for these tests was to quantify the impact of the installation effects

that occur in measuring low viscosity fluids ~ 1cSt.

At much higher viscosities these effects disappear.

The results shown are therefore only valid for low viscosities.

33

TEST SETUP 8”meterrun

11 beam Ultrasonic meter was used as a reference, positioned in the undisturbed section.

Test facility is Hycal, 1 cSt (test liquid is water 15..22ºC)

Test rates : 60, 110, 200, 375, 675, 1130 m3/h (0.5…10 m/s)

5 repeats per rate, 1 repeat is 100 seconds

Tested Flow conditioners

35

Flow conditioners used in the tests:

None

2D slide in ISO tube bundle

Spearman plate (similar to the CPA plate).

36

Reynolds independence

Meter response at various viscosities (0,64 – 169 cSt)

Uncorrected base lines:

0 D

3, 5 & 10 D

Tube FC

Tube FC

0 D, plate

FC

3, 5 & 10 D,

plate FC.

Perturbation tests:

Single Bend in plane, horizontal and vertical 10D..0D

Double out of plane bend, horizontal and vertical 10D..0D Concentric reducer

Results Single bend in plane (setup)

Horizontal setup

(3D inlet example)

Vertical setup

90º turn of meter

(10D inlet example)

Results Single bend in plane at 0D, 3D, 5D &10D no FC.

SINGLE BEND HORIZONTAL, NO FLOW CONDITIONING

-2.50

-2.00

-1.50

-1.00

-0.50

0.00

0.50

10000 100000 1000000 10000000

Re

Dev%

Err% --1.03cSt~inplaneH10D~(simu:1.03cSt)




SIMU rev5b (mode VISCO) Dev.Inp: 0.00[%]

Results Single bend in plane at 3D, 5D & 10 D no FC.

SINGLE BEND HORIZONTAL, NO FLOW CONDITIONING

-0.50

-0.40

-0.30

-0.20

-0.10

0.00

0.10

0.20

0.30

0.40

0.50

10000 100000 1000000 10000000

Re

Dev%






Results Single bend in plane at 3D, 5D & 10 D; 2D ISO Tube bundle

SINGLE BEND, 2D ISO TUBE BUNDLE

-0.50

-0.40

-0.30

-0.20

-0.10

0.00

0.10

0.20

0.30

0.40

0.50

10000 100000 1000000 10000000

Re

Dev%

Err% --1.02cSt~inplaneH10DTB~(simu:1.02cSt)

Err% --1.08cSt~inplaneH5D+5DTB2~(simu:1.08cSt)

Err% --1.09cSt~inplaneH5DTB2~(simu:1.09cSt)

Results Single bend in plane at 0D, 3D, 5D & 10 D; plate FC

SINGLE BEND, SPEARMAN PLATE

-0.50

-0.40

-0.30

-0.20

-0.10

0.00

0.10

0.20

0.30

0.40

0.50

10000 100000 1000000 10000000

Re

Dev%

Err% --1.02cSt~inplaneH10DHP~(simu:1.02cSt)



Err% --1.15cSt~InplaneH3D+0DHP~(simu:1.15cSt)


Double out-of-plane test results.

Double out-of-plane bends create swirl

Swirl has a major impact on the flow measurement

The decay of swirl depends on both the viscosity and time

Results double out-of-plane bend at 0D, 3D, 5D & 10 D; no FC.

DOUBLE BEND OUT OF PLANE,

NO FLOW CONDITIONING

-0.20

-0.10

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

10000 100000 1000000 10000000

Re

Err

%

Err% --1.17cSt~D-outplaneH10D~(simu:1.17cSt)





Double out-of-plane bend at 5D & 10 D; no 2D ISO tube bundle

DOUBLE BEND OUT OF PLANE

2D ISO TUBE BUNDLE

-0.50

-0.40

-0.30

-0.20

-0.10

0.00

0.10

0.20

0.30

0.40

0.50

10000 100000 1000000 10000000

Re

Err

%

Err% --1.13cSt~D-outplaneH10DTB2~(simu:1.13cSt)

Err% --1.05cSt~D-outplaneH5DTB2~(simu:1.05cSt)

Double out-of-plane bend at 0D, 3D, 5D & 10 D; plate FC

DOUBLE BEND OUT OF PLANE

SPEARMAN PLATE

-0.50

-0.40

-0.30

-0.20

-0.10

0.00

0.10

0.20

0.30

0.40

0.50

10000 100000 1000000 10000000

Re

Err

%

Err% --1.08cSt~D-outplaneH10DHP~(simu:1.08cSt)




Jan G. Drenthen &

Pico Brand

1. Introduction


3. Test results


• Meter proving

4. Conclusions

The API Ch 5.8 is based on turbine meters.

Turbine meters average the flow over the length of the rotor blade section and

are not capable to measure high frequency fluctuations. Ultrasonic meters detect

all these natural occurring fluctuations in the flow. Hence the output of ultrasonic

meters possess a much larger scatter than turbine meters.

To reduce the scatter to the level of the turbine meter, the ultrasonic meter must

average over a larger time/volume.

Proving according to API Ch 5.8

Proving ultrasonic meters with a SVP is not easy!

49

Runs Repeatability

Band % (R)

Uncert.

%

3 0,02 0,027

4 0,03 0,027

5 0,05 0,027

6 0,06 0,027

7 0,08 0,027

8 0,09 0,027

9 0,10 0,027

10 0,12 0,027

11 0,13 0,027

12 0,14 0,027

20 0,22 0,027

In the API ch. 5.8, 3 methods are described to calibrate a flowmeter with a SVP:

1. Performing 5 proving runs of

each 1 pass

2. Performing up to 20 proving runs

of each 1 pass

3. Performing 5 to 20 proving runs of

each a number of passes

(as an example 3, 5 or 10)

50

Minimum proving volume

The minimum proving volume is a function of:

The meter size.

The flow regime (laminar – transition – turbulent).

The turbulence level.

The number of acoustic paths.

The sampling rate.

In the design of the new Altosonic 5, both the number of paths as

well as the sampling rate have been optimized for use with SVP.

51

Recommended minimum proving volume

52

0.0

20.0

40.0

60.0

80.0

100.0

120.0

140.0

160.0

180.0

0 2 4 6 8 10 12 14

B

a

r

r

a

l

s

Inch

Required proving volume for an 0.027% uncertainty level A-V full bore

Altosonic 5 *new* full bore

A-V reduced bore

Altosonic 5 *new* reduced bore

52

lower is

better

Small volume prover test at Hycal

53

SUMMARY TEST RESULTS with a 60 litre base volume

4 inch ALTOSONIC V

repeatability

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0 2 4 6 8 10 12 14 16

Rep

eata

bilit

y

number of calibrations performed

Repeatability versus calibration method

5 x 5

5 x 10

3 x 20

Avg. of 5 x 5

Avg. of 5 x 10

Avg. of 3 x 20

API

Recommended test volume per repeat: 500 liter

Passed with:

5 x 10 and 3 x 20

54

5 x 300 L

5 x 600 L

3 x 1200 L

SUMMARY TEST RESULTS with a 60 litre base volume

6 inch ALTOSONIC V

repeatabilities

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0 1 2 3 4 5 6 7 8

Rep

eata

bilit

y

number of calibrations performed

Repeatability versus calibration method

5 x 5

5 x 10

3 x 20

5 x 5

5 x 10

3 x 20

Recommended test volume per repeat: 1900 liter

All tests failed!

Too small test volume!

55

5 x 300 L

5 x 600 L

3 x 1200 L

API

Recommendations on proving

Meter

inch

Altosonic 5

liter

Altosonic V

liter

Prover base

volume

liter

4

400

500

60 – 120

6

1.600

1.900

250

8

4.000

4.900

400 – 650

Recommended proving volumes per run:

Number of proving passes per run:

Using a 5 runs of a 10 passes average gave in most calibration the best results.

A duration of 1.5 seconds is sufficient to guarantee acceptable calibration results

for 5 runs of 10 passes each.

56

Jan G. Drenthen &

Pico Brand

1. Introduction


3. Test results


• Meter proving

4. Conclusions

Conclusions

Without proper flow conditioning, installation effects are apparent at low viscosities.

In combination with a perforated plate flow conditioner, even for low viscosities, the

design is robust and highly insensitive for installation conditions.

Using 7 beams, the minimal straight inlet length can be reduced to 3D – 5D.

0 D inlet runs are to be avoided in general, but can be used in certain applications

when it is calibrated as a package including the upstream piping.

Using Reynolds compensation, the meter has become independent of the liquid

properties.

With the new design, a compact prover can be used.

58

Gas and Liquid Metering Skid for CLOV deep water development

project. FPSO, Angola

| Major Projects Reference Overview

The King is dead…….

60

.. long live the new King

61

62

Any Questions?

63

In for a bite?

Jan G. Drenthen &

Pico Brand

Thank you for your attention!

installation effects on ultrasonic flow meters for liquids€¦ · installation effects on...

Documents