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Influence of Flow Disturbances on Measurement Uncertainty of Industry-Standard LNG Flow Meters- Highlights
Asaad Kenbar (NEL) & Menne Schakel (VSL)
LNGIII Workshop, 28 May 2020
Main objectives of this work
28/5/2020 LNGIII workshop 2
▪ Meet a target measurement uncertainty of 0.5% (k = 2) for small and mid-
scale LNG applications. Can we achieve this in practice?
▪ Investigate the effect of typical upstream flow disturbances on LNG flow
measurement uncertainty
▪ Investigate the effect of meter insulation on flow measurement uncertainty
▪ Assess transferability of meter calibrations with water at ambient conditions
to cryogenic conditions. Can we meet the 0.5% uncertainty above?
Experimental Programme
28/5/2020 LNGIII workshop 3
▪ A careful experimental programme was designed to achieve these objectives
▪ Six LNG flow meters were secured from 5 manufacturers (Endress + Hauser, Emerson,
Krohne, Yokogawa and Panametrics a Baker Hughes company) :
− 2 Coriolis (2” in size)− 2 Coriolis (4” in size) − 2 Ultrasonic (4” in size)
▪ Typical flow disturbances were selected and agreed
▪ Two metering skids were designed, one for the 2” meters and the other for the 4” meters
▪ These skids were tested with water at NEL first, then
▪ Tested with LIN in the VSL’s Cryogenic Research and Calibration Facility
LIN: Liquid nitrogen
Typical flow disturbances
28/5/2020 LNGIII workshop 4
Moderate From Kenbar & Schakel, submitted to FM&I, 2020
Severe
Metering configurations
LNGIII training 5
From Kenbar & Schakel, draft journal publication, 2020
Water calibrations at NEL
28/5/2020 6
Not displayed
Double bends
NEL’s Water Flow Measurement Facility
From Kenbar & Schakel, draft journal publication, 2020
Water calibrations- setups and test matrix
28/5/2020 LNGIII workshop 7
▪ I. Ideal setup: no flow disturbance (open plate), no insulation
▪ II. As setup I, but with partially blocking plate
▪ III. As setup I, but with double-bend disturbance
From Kenbar & Schakel, draft journal publication, 2020
Test matrix, 4” line
Cryogenic calibrations at VSL
8
VSL Cryogenic Research and Calibration Facility
2” metering line showing the double bend disturbance (1)
and part of its rockwool insulation (2)
From Schakel, 2019, VSL website
From Kenbar & Schakel, draft journal publication, 2020
Cryogenic calibrations- setups and test matrix
28/5/2020 9
▪ I. Ideal setup: no flow disturbance and all meters are insulated
▪ II. As setup I, but with partially blocking plate
▪ III. As setup I, but with double-bend disturbance
▪ IV. As setup I, but with flow meter insulation removed
From Kenbar & Schakel, draft journal publication, 2020
Calibration results
10
-1.0
-0.8
-0.6
-0.4
-0.2
0.0
0.2
0.4
0.6
0.8
1.0
0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0
Err
or
[%]
Mass Flow Rate [kg/s]
Water Flow TestsMeter 1
Ideal, 20 deg. C
Ideal, 36 deg. C
Partial blockage, 20 deg. C
Double-bend, 20 deg. C
-3.0
-2.5
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0
Err
or
[%]
Mass Flow Rate [kg/s]
Liquid Nitrogen Flow TestsMeter 1
Ideal
Ideal-repeat
Partial blockage
Double-bend
Un-insulated
Nominal
Rate
(kg/s) Ideal, 20 °C
1 -0.018
2 -0.010
3 0.048
4 0.044
5 0.017
6 0.004
7 -0.013
8.5 -0.018
Nominal
Rate
(kg/s) Ideal
2 -0.19
4 -0.10
6 -0.07
8 0.00
10 -0.04
From: Schakel (2019) & Kenbar & Schakel, draft journal publication, 2020From: Kenbar & Schakel, draft journal publication, 2020
The tables show the
averaged error for
each test point for
the ideal case
Calibration results
11
-1.0
-0.8
-0.6
-0.4
-0.2
0.0
0.2
0.4
0.6
0.8
1.0
0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0
Err
or
[%]
Mass Flow Rate [kg/s]
Water Flow TestsMeter 6
Ideal, 20 deg. C
Ideal, 36 deg. C
Partial blockage, 20 deg. C
Double-bend, 20 deg. C
Nominal
Rate
(kg/s) Ideal, 20 °C
1 -0.026
2 -0.020
3 0.036
4 0.036
5 0.016
6 0.007
7 -0.006
8.5 -0.010
Nominal
Rate
(kg/s) Ideal
2 0.26
4 0.44
6 0.52
8 0.60
10 0.59
From: Schakel (2019) & Kenbar & Schakel, draft journal publication, 2020From: Kenbar & Schakel, draft journal publication, 2020
Calibration results
10-6-2020 12
-1.0
-0.8
-0.6
-0.4
-0.2
0.0
0.2
0.4
0.6
0.8
1.0
0.0 5.0 10.0 15.0 20.0 25.0 30.0
Err
or
[%]
Mass Flow Rate [kg/s]
Water Flow Tests
Meter 0
Ideal, 20 deg. C
Ideal, 36 deg. C
Partial blockage, 20 deg. C
Double-bend, 20 deg. C
-3.0
-2.5
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
0 5 10 15 20
Err
or
[%]
Mass Flow Rate [kg/s]
Liquid Nitrogen Flow TestsMeter 0
Ideal
Ideal-repeat
Partial blockage
Double-bend
Un-insulated
Nominal
Rate
(kg/s) Ideal, 20 °C
7 -0.041
16 -0.017
25 -0.018
35 -0.012
Nominal
Rate
(kg/s) Ideal
4 -0.07
8 0.02
12
16 0.13
20 0.10
From: Schakel (2019) & Kenbar & Schakel, draft journal publication, 2020From: Kenbar & Schakel, draft journal publication, 2020
Calibration results
13
-1.0
-0.8
-0.6
-0.4
-0.2
0.0
0.2
0.4
0.6
0.8
1.0
0.0 5.0 10.0 15.0 20.0 25.0 30.0
Err
or
[%]
Mass Flow Rate [kg/s]
Water Flow Tests
Meter 3
Ideal, 20 deg. C
Ideal, 36 deg. C
Partial blockage, 20 deg. C
Double-bend, 20 deg. C
-3.0
-2.5
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
0 5 10 15 20
Err
or
[%]
Mass Flow Rate [kg/s]
Liquid Nitrogen Flow TestsMeter 3
Ideal
Ideal-repeat
Partial blockage
Double-bend
Un-insulated
Nominal
Rate
(kg/s)
Ideal,
20 °C
7 -0.107
12 -0.115
17 -0.123
22 -0.145
28 -0.137
Nominal
Rate
(kg/s) Ideal
4 -0.21
8 -0.20
12 -0.12
16 -0.12
20
From: Schakel (2019) & Kenbar & Schakel, draft journal publication, 2020From: Kenbar & Schakel, draft journal publication, 2020
Calibration results
14
-1.0
-0.8
-0.6
-0.4
-0.2
0.0
0.2
0.4
0.6
0.8
1.0
0.0 5.0 10.0 15.0 20.0 25.0 30.0
Err
or
[%]
Mass Flow Rate [kg/s]
Water Flow Tests
Meter 4
Ideal, 20 deg. C
Ideal, 36 deg. C
Partial blockage, 20 deg. C
Double-bend, 20 deg. C
-3.0
-2.5
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
0 5 10 15 20
Err
or
[%]
Mass Flow Rate [kg/s]
Liquid Nitrogen Flow TestsMeter 4
Ideal
Ideal-repeat
Partial blockage
Double-bend
Un-insulated
Nominal
Rate
(kg/s)
Ideal,
20 °C
7 -0.155
12 -0.148
17 -0.118
22 -0.111
28 -0.135
Nominal
Rate
(kg/s) Ideal
4 0.67
8 0.43
12 0.38
16 0.27
20
From: Schakel (2019) & Kenbar & Schakel, draft journal publication, 2020From: Kenbar & Schakel, draft journal publication, 2020
Calibration results
15
-1.0
-0.8
-0.6
-0.4
-0.2
0.0
0.2
0.4
0.6
0.8
1.0
0.0 5.0 10.0 15.0 20.0 25.0 30.0
Err
or
[%]
Mass Flow Rate [kg/s]
Water Flow Tests
Meter 8
Ideal, 36 deg. C
Partial blockage, 20 deg. C
Double-bend, 20 deg. C
-3.0
-2.5
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
0 5 10 15 20
Err
or
[%]
Mass Flow Rate [kg/s]
Liquid Nitrogen Flow TestsMeter 8
Ideal
Partial blockage
Double-bend
Un-insulated
Nominal
Rate
(kg/s)
Ideal,
36 °C
7 0.204
16 0.021
25 -0.035
Nominal
Rate
(kg/s) Ideal
4 0.29
8 -0.25
12
16 -0.22
20 -0.22
From: Schakel (2019) & Kenbar & Schakel, draft journal publication, 2020
From: Kenbar & Schakel, draft journal publication, 2020
Conclusions
28/5/2020 LNGIII workshop 16
▪ For water testing, the combined measurement uncertainty (facility + meter) varied
between 0.10% and 0.14% over the test flow range for all test cases.
▪ Therefore, the measurement accuracy of 0.10% to 0.15% specified by meter
manufacturers are generally met since the measured error was within its accuracy
band.
▪ The corrections used to transfer the water calibration to LIN conditions resulted in meter
errors, for the ideal case, within ±0.50% for about 85% of the results. However, it is
important to note that the correction models are specific to the meter type and
manufacturer.
▪ Also, the target measurement uncertainty of 0.50% can be achieved if the expanded
standard error of the mean value measured by the meter is smaller than 0.40%.
Conclusions continued
28/5/2020 LNGIII workshop 17
▪ The influence of flow disturbances is limited (meter error below ±0.50%), however,
these disturbances were followed by straight piping equivalent to 20D. This conclusion
will be substantiated further when testing repeated with LNG.
▪ The influence of meter insulation can be more significant than the influence of the
tested disturbances (meter error > ±0.50%) .
▪ The results presented here cannot be extrapolated, with meaningfully low uncertainty,
to flow meters of different type, size, model and make (manufacturer) than those tested
▪ Many of the above conclusions will be substantiated further when testing is conducted
with LNG in the future
▪ Future work will include other effects such as 2-phase flow and meter orientation.
Acknowledgment
28/5/2020 LNGIII workshop 18
The participation and support received from the LNG flow meter
manufacturers is highly appreciated!
Thanks to:
▪Panametrics a Baker Hughes company,
▪Emerson,
▪Endress + Hauser,
▪KROHNE, and
▪Yokogawa