The new Closed Loop pigsar and its projected CMC - efmws.eu · CMC Uncertainty (𝑘=2) 0,10% **...

The new Closed Loop pigsar

and its projected CMC

Jos van der Grinten, Detlef Vieth, Bodo Mickan

6th EFMWS - Barcelona, 16 - 19 April 2018 2 Jos van der Grinten, Detlef Vieth, Bodo Mickan | CLP Uncertainty

Contents

▪ Introduction

▪ pigsar Calibration facilities

▪ Closed Loop pigsar (CLP)

▪ Calibration model

▪ Uncertainty analysis

▪ Traceability chain

▪ Current – Expansion – new developments

▪ Harmonized cubic metre

▪ Conclusions


Introduction

Pigsar

▪ 1993

▪ 2003

▪ 2012

▪ 2013

▪ High accuracy calibrations

▪ ISO 17025 from DAkkS

▪ staatlich anerkannte Prüfstelle

▪ MID Module D

PTB

▪ 1887 established as PTR

Werner von Siemens

Hermann von Helmholz

▪ Top 3 of NMIs in the world

▪ Nobel prize winners

▪ SI units

▪ Industrial calibrations

▪ Legal metrology

▪ International cooperation


German National Standard

German National standard HP gas at pigsar

▪ High Pressure Piston Prover (1999)

▪ Critical flow Venturi nozzles

▪ Optical velocity standard (LDA – principle)

HPPP

Sonic nozzles

LDA


Challenges

▪ Ultrasonic meters higher flowrates at the same D

▪ Bigger metering stations use DN400 – DN600 meters

▪ Customers require more flexibility

▪ HP transportation network does not become easier for bypass test facilities

▪ There are several new test facilities planned and in operation

▪ Closed loop concepts “work”

Decision taken to build a new closed loop facility at pigsar

New traceability chain?! Measurement uncertainty?! New primary standard?!


pigsar calibration facilities

Please note: The as-built facility may differ slightly from the information shown here.


Closed Loop pigsar (CLP)

F

F

F

F

control room

energy supply

blower,

transformer

electrics,

metering,

control system

test sections

reference meter runs

primary + secondary references

hig

h p

ressu

re

Blo

we

r

Coo

ling

ga

s s

up

ply



Comparison of test facilities

Closed Loop pigsar Current bypass pigsar

Actual volume flowrate 40 – 22 000 m3/h 3 – 6 500 m3/h

Absolute pressures 8 – 65 bar 17 – 50 bar *

Meter diameters DN200 – DN600 mm (8” – 24“) DN50 – DN 400 mm (2” – 16”)

Flanges and

pressure classes

ANSI 150 – 1500,

PN 16 – 64 **

ANSI 150 – 1500,

PN 16 – 64 **

Length of test section 24 and 33 meter 8 – 22 meter

Fluid Natural gas Natural gas

CMC uncertainty (𝑘=2) 0.13% – 0.18% 0.13% – 0.16%

Reference turbine meters 3 x 6” G400 + 3 x 20” G6500 4 x 4” G250 + 4 x 8” G1000

8 – 17 bar available on request ** Other flanges and pressure classes upon request



Calibration model

▪ Mass conservation ▪ Line-pack Correction

▪ Integer pulse measurement ▪ 𝑝 = 𝜌 Τ𝑅 𝑀 𝑍 𝑇 𝑍(𝑝, 𝑇, 𝑥)

▪ Corrections for all systematic deviations

Reference MuT

(2) (1)

p pt t


Uncertainty analysis

▪ When Line Pack can be neglected, is

▪ 𝑒𝑀𝑢𝑇 =𝑝𝑀𝑢𝑇

𝑝𝑀𝑢𝑇 + ∆𝑝

𝑁𝑀𝑢𝑇

𝑁𝑀𝑀

𝐼𝑀𝑀

𝐼𝑀𝑢𝑇

𝜏𝑀𝑀

𝜏𝑀𝑢𝑇

𝑍𝑀𝑀

𝑍𝑀𝑢𝑇

𝑇0 + 𝑡𝑀𝑀

𝑇0 + 𝑡𝑀𝑢𝑇− 1

▪ 𝑍 = 𝑧0 + 𝑍𝑖, 𝑧0 = 0, 𝑍𝑖 = 𝑍𝑖(𝑝, 𝑇, 𝑥)

▪ 𝑈(𝑧0) = 0.1% Uncertainty Algorithm ▪ 𝑈 𝑍𝑖 =𝜕𝑍𝑖

𝜕𝑝𝑈 𝑝𝑖

2

+𝜕𝑍𝑖

𝜕𝑡𝑈 𝑡𝑖

2

▪ 𝑈 𝑥𝑖 ≈ 10−7 Gas quality can be neglected


Uncertainty – Monte CarloQuantity Unit X PDF mu sigma nu a b d x q Detail y Detail u(y)

pMuT bar X(1) Gaussian 50 0.0075 2.75E-06

∆pMM-MuT bar X(2) Gaussian 1 0.0052 1.03E-04

tMuT °C X(3) Gaussian 19 0.0451 1.55E-04

tMM °C X(4) Gaussian 20 0.0451 1.54E-04

T0 K X(5) Constant 273.15 0

NMuT - X(6) Constant 66000 0

NMM - X(7) Constant 65000 0

τMuT s X(8) Gaussian 100 0.0001 1.00E-06

τMM s X(9) Gaussian 100 0.0001 1.00E-06

z0 - X(10) Gaussian 0 0.10% 5.04E-07

ZMuT - X(11) Gaussian 0.89348 7E-05 7.45E-05

ZMM - X(12) Gaussian 0.89290 7E-05 7.47E-05

eMM - X(13) Gaussian 0.10% 0.08% 8.01E-04

eMuT,rep - X(14) Gaussian 0.00% 0.005% 5.00E-05

IMuT imp / m³ X(15) Constant 650 0

IMM imp / m³ X(16) Constant 650 0

Vdead m³ X(17) Gaussian 5 0.1 2.69E-05

τV s X(18) Gaussian 100 0.0001 1.34E-09

pstart bar X(19) Gaussian 50 0.0075 7.35E-06

pend bar X(20) Gaussian 51 0.0075 7.40E-06

tstart °C X(21) Gaussian 20.5 0.0451 7.51E-06

tend °C X(22) Gaussian 19.5 0.0451 7.75E-06

Zstart - X(23) Gaussian 0.89561 7E-05 3.64E-06

Zend - X(24) Gaussian 0.89218 7E-05 3.75E-06

Utot = 8,4·10-4


Uncertainty analysis

Order of magnitude uncertainty Source

Actual flowrate 10-3 Traceability

Pressure difference and Temperature 10-4 Process

Repeatability MuT 10-4 Repeatability

Pressure 𝑝𝑀𝑢𝑇 10-6 Process

Time interval measurements 10-6 Process

Compressibility algorithm 𝑼(𝒛𝟎) = 𝟎. 𝟏% 10-6 Process

Gas composition [Literature] 10-7 ~ 10-8 Process


Traceability – expansion

▪ HPPP 0.050%

▪ process conditions 0.056%

▪ repeatability 0.01%

Existing traceability chain Expansion

Flow range

3 - 480

m³/h

20 - 400 m³/h

3 - 20 - 1600 m³/h

80 - 1600

m³/h

80 - 6500 m³/h

320 -

6500 m³/h

40 - 22000 m³/h

m → Piston prover

→ 2 x

G250 →

1xG160 4xG250 master

→ 2xG1000 Transfer

→ 4 x

G1000 master

→

2xG250 2xG1000 2xG6500

→ →

3 x G400

G6500

↓ ↓ ↓

MuT MuT MuT

Target CMC 0,13% 0,16% 0,18%

pigsar

Closed Loop pigsar

▪ Long-term stability 0.075%

Target CMCs achievable


Traceability

Everywhere the same question:

▪ "How far can you reduce measurement uncertainty?“

▪ "Is 0.10% available?"

New developments:

▪ Use correlations, example compressibility

▪ Traceability with fewer steps Transfer package

▪ Combining parallel, independent feedback chains?

Internal harmonized m³:

▪ Existing HPPP ▪ Critical flow Venturi nozzles

▪ New test standard: high-pressure comparator


Transfer standards

DN 100

TM

T

TM

TM

T

T

DN 200

DN 200

DN 250DN 250

(a)

TM 2

TDN 400

TM 1

TDN 400

(b)



Critical flow Venturi nozzles

▪ Measuring dimensions

▪ Boundary layer theory

(turbulent and laminar)

▪ Calibration with air

Application with Natural Gas


Critical flow Venturi nozzle

50 bar natural gas


New High-Pressure Comparator

Thermal flow sensor

Comparator cannula

Distance sensor

Reflector

plug

Cable drum

Piston sensorsPower

10”prototype


New High-Pressure Comparator

New HP Comparator HP Piston Prover

Actual volume flowrate 40 - 1600 m3/h 3 – 480 m3/h

Absolute pressure 8 – 65 bar 17 – 50 bar *

Tube diameter DN 600 mm DN 250 mm

Piston stroke / effective stroke 6 m / 4 m 6 m / 3 m

Maximum piston velocity 1,8 m/s 3 m/s

Fluid Natural gas / air Natural gas

CMC Uncertainty (𝑘=2) 0,10% ** 0,065%

* 8 – 17 bar available on request ** Initial value, to be improved



Traceability


Harmonized cubic meter

▪ Intercomparison 8 – 20 – 50 bar, 20 – 6500 m³/h

▪ 2x DN100 + 2x DN150 + 2x DN250 + 2x DN400

▪ Parallel working standards higher harmonized flowrates reachable

▪ Harmonized m³ for flowrates > 6500 m3/h

▪ < 2014 NL only

▪ 2014 NL + DK

▪ 2020 NL + DK + DE

▪ Expanded measurement capabilities pigsar

▪ Also at 8 und 65 bar

▪ More labs smaller measurement uncertainty

better long-time stability

m³


Conclusions

▪ The new Closed Loop pigsar (CLP) is under construction

▪ Parallel operation of both facilities possible

▪ Measurement capabilities are expanded with respect to pressure and flow

▪ Improved traceability for the industry

▪ By extending today’s traceability chain,

the target CMC measurement uncertainties can be achieved

▪ new developments

▪ Transfer standards, HP comparator, parallel traceability

▪ Reduction of measurement uncertainties

▪ Better fundament for the harmonized cubic meter


Questions

?

Physikalisch-Technische Bundesanstalt

Braunschweig und Berlin

Bundesallee 100

38116 Braunschweig, Germany

Dr. Jos van der Grinten & Dr. Bodo Mickan

Telephone: +49 531 592 1425 / … 1331

E-Mail: [email protected] / [email protected]

pigsarTM

Vier Gas Services GmbH & Co. KG

Halterner Straße 125

46284 Dorsten, Germany

Dr. Detlef Vieth

Telephone: +49 2362 93 8678

E-Mail: [email protected]

www.pigsar.de

http://www.ptb.de/

http://www.pigsar.de/

The new Closed Loop pigsar and its projected CMC - efmws.eu · CMC Uncertainty (𝑘=2) 0,10% **...

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