1. APMP TC Fluid Flow Initiative Project Traceability Scheme Study for LPG Metering Final Report at APMP 2012 TCFF Meeting Chun-Min Su CMS/ITRI, Chinese Taipei Nov. 26, 2012 Wellington, New Zealand

2. Copyright 2009 ITRI 工業技術研究院 Project Name –Traceability Scheme Study for LPG Metering Key Members –Overseer: Dr. Jiunn-Haur Shaw (CMS) –Co-Leader: Dr. Yoshiya Terao (NMIJ, TCFF Chair) –Collaborator: Dr. John Man (NMIA) Background and Objective of the Project –Transaction of LPG requires the support of sound national metrology scheme to ensure its fairness –Objective: to research on the traceability scheme for LPG transfer standard (TS) and correction factor based on the actual fluid (propane and butane) and water as working fluid, so that NMIs maintaining LPG legal measurement infrastructure could simplify the traceability method by utilizing water as test medium while keeping the same accuracy Project Budget and Its Use –US$6000, to be used in transportation of the TS, custom, meter testing, data analysis and training Project Overview 2

3. Copyright 2009 ITRI 工業技術研究院 Method Coriolis mass flow meter chosen as the transfer standard (TS) –Measures mass flow directly –Can be used for a variety of fluids under extended range of pressure (and temperature) –Capable of measuring fluid density Verify the flow measurement performance of the TS and, if necessary, identify possible method of correction –Calibrate the TS with different working fluid: water and LPG (propane and butane) –Calibrate the TS at different pressures Check the density measurement performance of the TS and establish the traceability 3

4. Copyright 2009 ITRI 工業技術研究院 4 Concept of Verifying LPG Fuel Dispensers by Coriolis Mass Flow Meter LPG Fuel Dispensers V FD Master Meter (Coriolis Meter) M mm,  (T mm,P mm ), T mm, P mm NIST REFPROP 8.0:  (T mm,P mm ) x C3H8, x C4H10 (molar fraction) Thermometer + Pressure Gauge T FD, P FD  (T FD,P FD ) NIST REFPROP 8.0: x C3H8, x C4H10, T FD,P FD  (T FD,P FD ), or  (15,P FD ), V FD : Volume indicated by fuel dispenser in temperature uncompensated mode V FD,C : V FD converted to base conditions

5. Copyright 2009 ITRI 工業技術研究院 The TS Package Micro Motion CMF050 mass flow meter with MVD transmitter, std. core processor –Maximum flow rate: 6800 kg/h = 113.3 kg/min –Accuracy of mass flow: 0.1 % –Repeatability of mass flow: 0.05 % –Zero stability: 0.163 kg/h –Accuracy of density: 0.5 kg/m 3 –Repeatability of density: 0.2 kg/m 3 Explosion-proof thermometer & pressure gauge 5 Cable Soft pad

6. Copyright 2009 ITRI 工業技術研究院 6 Small water flow standard calibration facility at CMS Temperature: 10 ºC to 45 ºC, Pressure : 50 kPa to 500 kPa, Volume flow rate: 2 L/min to 700 L/min, Mass flow rate: 2 kg/min to 700 kg/min, Accumulated volume: 0.02 m 3 to 0.6 m 3, Accumulated mass: 20 kg to 600 kg, Velocity: 0.1 m/s to 10 m/s. reservoir capacity : 3.2 m 3. System relative expanded uncertainty: Mass and volume: 0.03 %, Mass flow rate and volume flow rate: 0.04 %, Velocity: 1.00 %. 6

7. Copyright 2009 ITRI 工業技術研究院 NMIA LPG flow system Two 6000 L tanks, Propane & Butane Two pumps, giving flow rates of up to 1700 L/min At 20 ºC, 800 kPa (propane), 300 kPa (butane) Reference standard: 40 L piston prover Omni 6000 electronic controller Base uncertainty 0.03 % 7

8. Copyright 2009 ITRI 工業技術研究院 Test Schedule CMS-1 : 2011/10/03 to 2011/10/04 NMIA : 2011/10/19 to 2011/11/10 CMS-2 : 2012/03/19 to 2012/03/22

9. Copyright 2009 ITRI 工業技術研究院 Calibration of the TS @ CMS 9 Pressure regulator for pressure control and stabilization High pressure water pump Soft pad to isolate vibration (critical for zero setting) Small-diameter high-pressure hose and valve to avoid bubble generation in the downstream

10. Copyright 2009 ITRI 工業技術研究院 Calibration of the TS @ NMIA Propane @ 12 bars Butane @ 9 bars Flow rate: 10 kg/min 、 20 kg/min 、 30 kg/min 、 40 kg/min 、 50 kg/min 10

11. Copyright 2009 ITRI 工業技術研究院 Calibration of the TS @ NMIA 11

12. Copyright 2009 ITRI 工業技術研究院 1 st Test Results of Water Flow The tests were conducted at CMS before sending the TS to NMIA There seemed to be some pressure effect The maximum deviation in MF is 0.046 % between test result of upstream pressure 12 bar and 0.2 bar at 20 kg/m 3 error bar: base uncertainty of CMS’s facility (0.03 %)

13. Copyright 2009 ITRI 工業技術研究院 2 nd Test Results of Water Flow The tests were conducted at CMS after receiving the TS from NMIA Pressure effect? The maximum deviation in MF is 0.039 % between test result of upstream pressure 12 bar and 0.2 bar at 10 kg/m 3 error bar: base uncertainty of CMS’s facility (0.03 %)

14. Copyright 2009 ITRI 工業技術研究院 Test Results of LPG (Propane & Butane) Flows Propane: zero setting @ 12 bars, tested with volume flow output @ 12 bars Butane: zero setting @ 12 bars, tested with volume flow output @ 9 bars Deviation in MF between the two fluids is less than 0.06 % 14

15. Copyright 2009 ITRI 工業技術研究院 Evaluating the Results Expanded uncertainty: U base is the base expanded uncertainty of CMS’s water calibration system U rep1 is the expanded uncertainty of the 1 st calibration @ CMS U rep2 is the expanded uncertainty of the 2 nd calibration @ CMS d i is the maximum deviation in MF of three tests at the same flow rate To compare the results of CMS and NMIA, the averaged MF of the two tests at CMS was used.

16. Copyright 2009 ITRI 工業技術研究院 Test Results at 12 bars Test results in CMS is the averaged MF of two tests The maximum deviation in MF is 0.06 % between CMS and NMIA results Deviation gets larger at higher flow rate (30, 40, 50) kg/min Propane

17. Copyright 2009 ITRI 工業技術研究院 Test Results at 9 bars Test results in CMS is the averaged MF of two tests The maximum deviation in MF is 0.05 % between CMS and NMIA results Larger deviation only at flow rate 50 kg/min Butane

18. Copyright 2009 ITRI 工業技術研究院 Evaluation of Inter-laboratory Equivalence The En value is calculated as follows: MF NMIA is the results of the tests in NMIA MF CMS is the averaged MF of the two tests in CMS U NMIA is the expanded uncertainty of NMIA LPG calibrations U CMS is the expanded uncertainty of CMS water calibrations

19. Copyright 2009 ITRI 工業技術研究院 En values are all smaller than 0.5 throughout the range of flow rate tested The Comparison Results

20. Copyright 2009 ITRI 工業技術研究院 Propane (kg/m 3 )Butane (kg/m 3 ) NMIA517571 TS516.8570.9 The Density Test Results in NMIA The measured density at observed conditions is converted to an equivalent density at 15 °C using API tables (NMIA testing procedures) Procedure to obtain (compensated) density through TS measurements: Record the density, pressure, and temperature at the same time when testing the TS at NMIA Calculate LPG composition by NIST REFPROP Calculate density of LPG at 15 °C Deviation in density measurement results between NMIA and the TS was less than 0.2 kg/m 3 (< 0.04 %)

21. Copyright 2009 ITRI 工業技術研究院 Summary Pressure effects can be ignored by the test results of test in CMS. For water flow system like CMS, it is important to avoid bubble formation in high pressure operation The fluid medium has little impact on the measuring results of the TS Deviation in density test results is less than 0.2 kg/m 3 (< 0.04 %) in actual fluid (propane and butane). Traceability of LPG flowmeter (Coriolis flowmeter) by can be established via calibration in water flow facility

22. Copyright 2009 ITRI 工業技術研究院 22 Thanks for your attention! Questions?