The new Closed Loop pigsar and its projected CMC. Jos van der Grinten, Detlef Vieth, Bodo Mickan

Transcription

1 The new Closed Loop pigsar and its projected CMC Jos van der Grinten, Detlef Vieth, Bodo Mickan

2 Introduction pigsar Calibration facilities Closed Loop pigsar (CLP) Calibration model Uncertainty analysis Traceability chain Contents Current Expansion new developments Harmonized cubic metre Conclusions 6th EFMWS - Barcelona, April Jos van der Grinten, Detlef Vieth, Bodo Mickan CLP Uncertainty

3 Introduction Pigsar High accuracy calibrations ISO 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 6th EFMWS - Barcelona, April Jos van der Grinten, Detlef Vieth, Bodo Mickan CLP Uncertainty

4 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 LDA Sonic nozzles 6th EFMWS - Barcelona, April Jos van der Grinten, Detlef Vieth, Bodo Mickan CLP Uncertainty

5 Ultrasonic meters Challenges 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?! 6th EFMWS - Barcelona, April Jos van der Grinten, Detlef Vieth, Bodo Mickan CLP Uncertainty

6 pigsar calibration facilities Please note: The as-built facility may differ slightly from the information shown here. 6th EFMWS - Barcelona, April Jos van der Grinten, Detlef Vieth, Bodo Mickan CLP Uncertainty

7 gas supply high pressure Blower Cooling Closed Loop pigsar (CLP) primary + secondary references F F reference meter runs F F energy supply blower, transformer electrics, metering, control system test sections control room Please note: The as-built facility may differ slightly from the information shown here. 6th EFMWS - Barcelona, April Jos van der Grinten, Detlef Vieth, Bodo Mickan CLP Uncertainty

8 Comparison of test facilities Closed Loop pigsar Current bypass pigsar Actual volume flowrate m 3 /h m 3 /h Absolute pressures 8 65 bar bar * Meter diameters DN200 DN600 mm (8 24 ) DN50 DN 400 mm (2 16 ) Flanges and pressure classes ANSI , PN ** ANSI , PN ** 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 G x 20 G x 4 G x 8 G bar available on request ** Other flanges and pressure classes upon request Please note: The as-built facility may differ slightly from the information shown here. 6th EFMWS - Barcelona, April Jos van der Grinten, Detlef Vieth, Bodo Mickan CLP Uncertainty

9 Calibration model Mass conservation Integer pulse measurement Line-pack Correction p = ρ R ΤM Z T Z(p, T, x) Corrections for all systematic deviations p t (2) (1) p t Reference MuT 6th EFMWS - Barcelona, April Jos van der Grinten, Detlef Vieth, Bodo Mickan CLP Uncertainty

10 When Line Pack can be neglected, is Uncertainty analysis e MuT = p MuT p MuT + p N MuT N MM I MM I MuT τ MM τ MuT Z MM Z MuT T 0 + t MM T 0 + t MuT 1 Z = z 0 + Z i, z 0 = 0, Z i = Z i (p, T, x) U(z 0 ) = 0.1% Uncertainty Algorithm U Z i = Z i p U p i 2 + Z i t U t i 2 U x i 10 7 Gas quality can be neglected 6th EFMWS - Barcelona, April Jos van der Grinten, Detlef Vieth, Bodo Mickan CLP Uncertainty

11 Uncertainty Monte Carlo Quantity Unit X PDF mu sigma nu a b d x q Detail y Detail u(y) p MuT bar X(1) Gaussian E-06 p MM-MuT bar X(2) Gaussian E-04 t MuT C X(3) Gaussian E-04 t MM C X(4) Gaussian E-04 T 0 K X(5) Constant N MuT - X(6) Constant N MM - X(7) Constant τ MuT s X(8) Gaussian E-06 τ MM s X(9) Gaussian E-06 z 0 - X(10) Gaussian % 5.04E-07 Z MuT - X(11) Gaussian E E-05 Z MM - X(12) Gaussian E E-05 U tot = 8, e MM - X(13) Gaussian 0.10% 0.08% 8.01E-04 e MuT,rep - X(14) Gaussian 0.00% 0.005% 5.00E-05 I MuT imp / m³ X(15) Constant I MM imp / m³ X(16) Constant V dead m³ X(17) Gaussian E-05 τ V s X(18) Gaussian E-09 p start bar X(19) Gaussian E-06 p end bar X(20) Gaussian E-06 t start C X(21) Gaussian E-06 t end C X(22) Gaussian E-06 Z start - X(23) Gaussian E E-06 Z end - X(24) Gaussian E E-06 6th EFMWS - Barcelona, April Jos van der Grinten, Detlef Vieth, Bodo Mickan CLP Uncertainty

12 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 p MuT 10-6 Process Time interval measurements 10-6 Process Compressibility algorithm U(z 0 ) = 0. 1% 10-6 Process Gas composition [Literature] 10-7 ~ 10-8 Process 6th EFMWS - Barcelona, April Jos van der Grinten, Detlef Vieth, Bodo Mickan CLP Uncertainty

13 Traceability expansion Flow range m³/h Existing traceability chain m³/h m³/h m³/h m³/h m³/h Expansion m³/h m Piston prover 2 x G250 1xG160 4xG250 master 2xG1000 Transfer 4 x G1000 master 2xG250 2xG1000 2xG x G400 G6500 MuT MuT MuT Target CMC 0,13% 0,16% 0,18% pigsar Closed Loop pigsar HPPP 0.050% process conditions 0.056% repeatability 0.01% Long-term stability 0.075% Target CMCs achievable 6th EFMWS - Barcelona, April Jos van der Grinten, Detlef Vieth, Bodo Mickan CLP Uncertainty

14 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 6th EFMWS - Barcelona, April Jos van der Grinten, Detlef Vieth, Bodo Mickan CLP Uncertainty

15 Transfer standards (a) T DN 100 DN 200 T TM T TM DN 200 DN 250 TM DN 250 (b) T DN 400 T DN 400 TM 2 TM 1 Please note: The as-built facility may differ slightly from the information shown here. 6th EFMWS - Barcelona, April Jos van der Grinten, Detlef Vieth, Bodo Mickan CLP Uncertainty

16 Critical flow Venturi nozzles Measuring dimensions Boundary layer theory (turbulent and laminar) Calibration with air Application with Natural Gas 6th EFMWS - Barcelona, April Jos van der Grinten, Detlef Vieth, Bodo Mickan CLP Uncertainty

17 Critical flow Venturi nozzle 50 bar natural gas 6th EFMWS - Barcelona, April Jos van der Grinten, Detlef Vieth, Bodo Mickan CLP Uncertainty

18 New High-Pressure Comparator Distance sensor Piston sensors Power Cable drum Comparator cannula Thermal flow sensor plug 10 prototype Reflector 6th EFMWS - Barcelona, April Jos van der Grinten, Detlef Vieth, Bodo Mickan CLP Uncertainty

19 New High-Pressure Comparator New HP Comparator HP Piston Prover Actual volume flowrate m 3 /h m 3 /h Absolute pressure 8 65 bar 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 Please note: The as-built facility may differ slightly from the information shown here. 6th EFMWS - Barcelona, April Jos van der Grinten, Detlef Vieth, Bodo Mickan CLP Uncertainty

20 Traceability 6th EFMWS - Barcelona, April Jos van der Grinten, Detlef Vieth, Bodo Mickan CLP Uncertainty

21 Harmonized cubic meter Intercomparison bar, m³/h 2x DN x DN x DN x DN400 Parallel working standards higher harmonized flowrates reachable Harmonized m³ for flowrates > 6500 m 3 /h < NL only NL + DK NL + DK + DE Expanded measurement capabilities pigsar Also at 8 und 65 bar More labs smaller measurement uncertainty better long-time stability m³ 6th EFMWS - Barcelona, April Jos van der Grinten, Detlef Vieth, Bodo Mickan CLP Uncertainty

22 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 6th EFMWS - Barcelona, April Jos van der Grinten, Detlef Vieth, Bodo Mickan CLP Uncertainty

23 Questions? 6th EFMWS - Barcelona, April Jos van der Grinten, Detlef Vieth, Bodo Mickan CLP Uncertainty

24 pigsar TM Vier Gas Services GmbH & Co. KG Halterner Straße Dorsten, Germany Dr. Detlef Vieth Telephone: Physikalisch-Technische Bundesanstalt Braunschweig und Berlin Bundesallee Braunschweig, Germany Dr. Jos van der Grinten & Dr. Bodo Mickan Telephone: / jos.v.grinten@ptb.de / bodo.mickan@ptb.de