Transcript 投影片 1

APMP TC Fluid Flow Initiative Project
Traceability Scheme Study for LPG Metering
Progress Report at APMP 2011 TCFF Meeting
Chun-Min Su, Ph.D.
Center for Measurement Standards, ITRI
Dec. 5, 2011
Project Overview
• 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
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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
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The TS Package
• Micro Motion CMF050 mass flow meter with MVD transmitter,
std. core processor
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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/m3
Repeatability of density: 0.2 kg/m3
Loaned by Micro
Motion free of
charge for one year
• Explosion-proof thermometer & pressure gauge
Soft pad
Cable
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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 m3 to 0.6 m3, Accumulated mass: 20 kg to 600 kg,
Velocity: 0.1 m/s to 10 m/s.
reservoir capacity : 3.2 m3.
System relative expanded uncertainty:
Mass and volume: 0.03 %, Mass flow rate and volume flow rate: 0.04 %, Velocity: 1.00 %.
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Calibration of the TS @ CMS
• 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
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NMIA LPG flow system
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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 %
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Calibration of the TS @ NMIA
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Propane @ 12 bars
Butane @ 9 bars
Flow rate: 10 kg/min、20 kg/min、30 kg/min
、40 kg/min、50 kg/min
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Calibration of the TS @ NMIA
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Test Results of Water Flow
Zero setting @ 12 bar, Test @ 12bar
Zero setting @ 12 bar,Test @ 9bar
zero setting @ 0.3bar, test @ 0.3bar
1.001
1.0008
MF
1.0006
1.0004
1.0002
1
0.00
10.00
20.00
30.00
40.00
50.00
60.00
Flow rate (kg/min)
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Under the same upstream pressure, the deviation in meter factor (MF)
is less than 0.04 %
Deviation in MF less than 0.04 % between test results of upstream
pressure 9 bars and 0.3 bar
Deviation in MF less than 0.05 % between test results of upstream
pressure 12 bars and 0.3 bar
Pressure effect on the meter performance can be observed
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Test Results of LPG (Propane & Butane) Flows
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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 %
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Check for Density Measurement
Performance of the TS
Standard
Measurement
0.71645
0.7164
3
Density (g/cm )
0.71635
0.7163
0.71625
0.7162
0.71615
0.7161
0.71605
0.716
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28.05
28.1
28.15
28.2
28.25
28.3
28.35
28.4
28.45
o
Temperature ( C)
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Test fluid: Exxsol DSP 80 (chemical solvent, Hydrocarbons)
Tested under normal pressure
The maximum deviation less than 0.0001 g/cm3
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Summary
• Progress
– Flow measurement performance of the TS with various working fluids
(water @ CMS; propane and butane @ NMIA) under pressures of 0.3
bar, 9 bars and 12 bars tested
• Overall speaking, the meter performance is very good
• Pressure effect on the meter performance observed in water flow system but not
significant in LPG system
• Additional lessons learnt for meter calibration at elevated pressure using
gravimetric water flow system
– Pressure regulator to improve pressure stability
– Small-dia. high-Pressure hose and valve to avoid bubble formation in the downstream
– Density measurement performance of the TS tested
• Future Work
– Re-calibrate the TS @ CMS to check for meter stability
– Re-calibrate the TS @ CMS at downstream pressures of 12 bars and 9
bars (same as the condition at NMIA)
– Re-test the TS @ CMS with volume flow (pulses per liter) signal output
– Analyze the data obtained by CMS and NMIA and see if varying
working fluid impacts the meter performance
– Test the density measurement performance of the TS at high-pressure
– NMIA will continue to work on establishing a method for LPG density
measurement at different temperatures
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The Hard-workers
Subra
(NMIA)
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Kun-Chih Tsai
(CMS)
Simon Dignan
(NMIA)
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Thanks for your attention!
Questions?
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Concept of Verifying LPG Fuel Dispensers by
Coriolis Mass Flow Meter
Thermometer
+ Pressure Gauge
TFD, PFD
(TFD,PFD)
Master Meter
(Coriolis Meter)
Mmm,  (Tmm,Pmm),
Tmm, Pmm
NIST REFPROP 8.0: (Tmm,Pmm)
xC3H8, xC4H10 (molar fraction)
(TFD,PFD), or (15,PFD),
NIST REFPROP 8.0: xC3H8, xC4H10, TFD,PFD
VREF 
M mm  MF
 (TFD , PFD )
M mm  MF
VREF,15 
 (15, PFD )
LPG Fuel Dispensers
VFD
V V
E  FD REF
VREF
E
VFD,C  VREF,15
VREF,15
VFD: Volume indicated by fuel dispenser in temperature uncompensated mode
VFD,C: VFD converted to base conditions
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Test Conditions @ NMIA
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