Dave van Woensel 08 June Installation effects in ultrasonic gas flow meters Calibration results of a Z-configuration measurement skid

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1 Dave van Woensel 08 June 2017 Installation effects in ultrasonic gas flow meters Calibration results of a Z-configuration measurement skid

2 1. Installation Effects 2. Skid Calibration 3. Results Ultrasonic flowmeter for Custody Transfer Agenda

3 Customer request Will the meter measure as accurate as calibrated once assembled on the skid? 3

40% 60% 80% 100% -0,50% OOP 10D 0deg OOP 10D 90deg OOP Exp.

4 Uncertainty Installation effects 2,00% 0,50% 1,50% 0,40% (Initial) Base 15 bar 1,00% 0,30% 0,20% 0,10% 0,00% -0,10% -0,20% -0,30% -0,40% Base 15 bar FC Base 10 bar Diameter step +3% 0,50% Diameter step -3% 0,00% Elbow 10D 0deg Elbow 10D 90deg 0% 20% 40% 60% 80% 100% -0,50% OOP 10D 0deg OOP 10D 90deg OOP Exp. 10D 0deg -1,00% Base 15 bar REVERSE -1,50% Renewed base 15 bar Elbow 10D 0deg -2,00% -0,50% Renewed base 15 bar repeat flow rate (Qmax = m3/h) 4

5 Swirl 5

6 Swirl and flow conditioning Computational Fluid Dynamics (CFD) 6

7 Remaining swirl after flow conditioner Most swirl has been removed 7

8 Swirl causing meter to overread 8

9 Swirl causing meter to underread 9

10 Swirl compensation in plane 10

11 Multiple paths for flow profile recognition 11

How standards describe installation effects 1.0 0.8 0.6 0.4 0.2 0-0.2-0.4-0.6-0.8-1.

12 How standards describe installation effects Calibrate meter under ideal conditions Redo calibration with upstream disturbance, manufacturer to advise required upstream piping to comply to standard and class Allowed deviation depends on standard and accuracy class Qmin Qt Qmax 12

13 Allowed deviations due to installation effects OIML R137 class 1 OIML R137 class 0.5 AGA 9 ISO ± 0.33% (1/3th of class) ± 0.17% (1/3th of class) Perturbation testing is done during one-off type test Uncertainty due to installation effect comes on top of regular calibration result (installation effects are not seen during a regular calibration) OIML certificates are issued by an independent 3 rd party (e.g. NMi, PTB). AGA9 and ISO compliance is not checked by 3 rd party. ± 0.3% ± 0.3% 13

14 Example of perturbation tests ISO and OIML R137-1 requirement shown below 80D 80D 0 D 0D SB Re/Ex DBooP Dboop/Ex DBooP/Ex/HMP 14

15 1. Installation Effects 2. Skid Calibration 3. Results Ultrasonic flowmeter for Custody Transfer Agenda

16 Customer concern Will the meter measure as accurate as calibrated once assembled on the skid? The only way to find out is to calibrate the entire skid 16

17 Flow measurement skid required by customer 17

18 Flow measurement skid Normal operation Verification 18

19 Flow measurement skid Maintenance for duty meter Extra capacity 19

20 Force Technology small calibration loop Flowrates 8-10,000 m3/h Calibration pressure 0-50 barg Lab uncertainty

21 Skid calibration (2x 8 /1500#) 21

22 Skid calibrated at FORCE (Denmark) 22

23 Skid calibration (2x 8 /1500#) Meter B Meter A Calibration pressure 50 bar Flow rates loose meter calibration 62 m3/h (0,8 m/s) 2500 m3/h (31,3 m/s) Flow rates skid calibration 62 m3/h (0,8 m/s) 1875 m3/h (23,4 m/s) 23

24 1. Installation Effects 2. Skid Calibration 3. Results Ultrasonic flowmeter for Custody Transfer Agenda

25 Calibration of loose meters 5D 3D 25

26 Flow conditioner and upstream piping KROHNE Flowcon3 (modified Spearmann plate), position locked by bracket Inlet pipe permanently affixed to flow meter This is not normal procedure but specifically done for this project 26

27 Flow profiles at different flow rates Meter A, loose meter calibration 27

28 Flow profiles at different flow rates Meter A, loose meter calibration 28

29 Flow profiles at different flow rates Meter B, loose meter calibration 29

Modified flow conditioner to minimize noise production Flow conditioner of meter B produced ultrasonic noise at flowrates 2200 m3/h. Flow conditioner modified to reduce noise production.

30 Modified flow conditioner to minimize noise production Flow conditioner of meter B produced ultrasonic noise at flowrates 2200 m3/h. Flow conditioner modified to reduce noise production. After modification less noise and only starting at 2450 m3/h. Modifications caused flow profile of meter B to be slightly asymmetric (combination with upstream conditions). Noise production by flow conditioner occasionally happens and is a typical case of bad luck. 30

31 As left calibration results meter A and B Baseline after linearization 31

32 Calibration of meter A in skid B A Inlet conditions: - 3x 90 bend, 1x T-section, 1x 90 bend (all swirl generators) - 2 fully open ball valves, 6D straight - Flow conditioner, 5D straight (used in original meter calibration) 32

33 Flow profile meter A Loose meter vs meter in skid at 1500 m3/h 33

34 Calibration results meter A Loose meter vs meter in skid AGA 9/ ISO perturbation limits OIML R137 class 0.5 perturbation limits 34

35 Calibration of meter B in skid B A Inlet conditions meter B: - 3x 90 bend, 1x T-section, 1x 90 bend (all swirl generators) - 2 fully open ball valves, 6D straight - Flow conditioner, 5D straight (used in original meter calibration) 35

36 Flow profile meter B Loose meter vs meter in skid at 1500 m3/h 36

37 Calibration results meter B Loose meter vs meter in skid AGA 9/ ISO perturbation limits OIML R137 class 0.5 perturbation limits 37

38 Calibration of meter A and B in skid Meter B Meter A Inlet conditions meter A: - 3x 90 bend, 1x T-section, 1x 90 bend (all swirl generators) - 2 fully open ball valves, 6D straight - Flow conditioner, 5D straight (used in original meter calibration) 38

39 Flow profile meter A at 1500 m3/h Loose meter vs meter in skid in Z-configuration 39

40 Calibration results meter A Skid in parallel vs Z AGA 9/ ISO perturbation limits OIML R137 class 0.5 perturbation limits 40

41 Calibration of meter A and B in skid B A Inlet conditions meter B: - 3x 90 bend, 1x T-section, 1x 90 bend (all swirl generators) - 2 fully open ball valves, 6D straight, flow conditioner, 15D straight - 1x T-section, 2x 90 bend, 1x T-section, 1D straight - Flow conditioner, 5D straight (used in original meter calibration) 41

42 Flow profile meter B at 1500 m3/h Loose meter vs meter in skid in Z-configuration 42

43 Calibration results meter B Skid in parallel vs Z AGA 9/ ISO perturbation limits OIML R137 class 0.5 perturbation limits 43

44 Summary and conclusions Due to overall length restrictions meter B in Z-mode only had 1D straight inlet (settling chamber) upstream of the flow conditioner, less then the required 2D. Despite the 1D settling chamber and significant perturbations all shift where well within AGA9 and ISO perturbation limits of ± 0.3%. All results, except the highest flow rate of meter B in Z-mode, were within the OIML R137 class 0.5 perturbation limits of ± 0.17%. The modulations based on the log files afterwards indicate a 1.4D settling chamber was required. So it is expected that with a 2D settling chamber also meter B in Z-mode would have been within the severe limits. Different flow profiles do not automatically mean bad results, if you can recognize them. 44

45 Summary and conclusions It is possible to calibrate a complete skid but even for a small skid is it a lot of work. Especially if the recalibration periods are short in the laws of the country. Z-configuration skids are perfectly possible with ultrasonic flowmeters. Calibrating result of meters remains valid when meters are placed in a skid, this means that there is no need to (re-)calibrate entire skids. Loose meters including upstream conditions seem sufficient. It would be interesting to do the same test without flow conditioners to see if results would be similar. But we would need a new customer with a special request! 45 To be continued

46 Thank you for your attention!

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