BORDER STATIONS WITH ULTRASONIC & TURBINE METERS IN SERIES Laurent Cordier Quality & Metrology (Fluxys Belgium)

Transcription

1 BORDER STATIONS WITH ULTRASONIC & TURBINE METERS IN SERIES Laurent Cordier Quality & Metrology (Fluxys Belgium)

2 1. Who is Fluxys? 2. Fluxys Border Stations 3. Metrological Maintenance 4. Conclusion

3 FLUXYS: GAS INFRASTRUCTURE COMPANY Present across Europe Major gas transit operator Fully independent player SWEDEGAS Transmission GMSL BBL INTERCONNECTOR NEL EUGAL DUNKIRK LNG TERMINAL FLUXYS BELGIUM TENP Storage TRANSITGAS TAP LNG terminalling

4 Shareholding & group structure Publigas Caisse de dépôt et placement du Québec Federal holding and Investment Company Employees and management 77.51% 19.91% 2.13% 0.45% 90.00% 100% FLUXYS BELGIUM Regulated activities in Belgium FLUXYS EUROPE Non regulated activities in Belgium & activities outside Belgium 10.00% Listed shares (NYSE Euronext Brussels) Golden share Belgian state

5 KEY ASSET: TRANSMISSION INFRASTRUCTURE UNITED KINGDOM NORWAY LNG NETHERLANDS ZELZATE ZANDVLIET Loenhout NETHERLANDS HILVARENBEEK ZEEBRUGGE Brugge Antwerpen Sint-Niklaas Mechelen DILSEN NORWAY / GERMANY 4,000 km pipelines FRANCE ALVERINGEM Kortrijk Tournai Gent Aalst Brussels Winksele Genk Berneau Liège S-GRAVENVOEREN NORWAY / GERMANY Verviers RUSSIA / GERMANY EYNATTEN High calorific gas Low calorific gas Mons Charleroi Namur Physical interconnection points LNG terminal Compressor stations BLAREGNIES FRANCE SPAIN ITALY Libramont BRAS LUXEMBOURG Bastogne Arlon PÉTANGE Blending stations Storage Zeebrugge area: throughput capacity of ~ 57 bcm/y = approximately 10% of border capacity needed to supply Europe LUXEMBOURG

6 KEY VALUE: ~60% OF INCOMING GAS VOLUMES TRANSIT FROM BORDER TO BORDER ~796 TWh Fluxys border stations ( 72bcm) ~189 TWh end users stations in Belgium ( 17bcm) MWh measured in Belgium (2017) EXIT POINTS; ,54 ENTRY POINTS; ,39 CONSUMED IN BELGIUM; ,85 ENTRY POINTS CONSUMED IN BELGIUM EXIT POINTS

7 BORDER STATIONS IS KEY Overall quantity of natural gas measured at 20 large-scale border stations Just 1/4 is measured at over 500 lower-capacity metering stations (large industries, power stations & public distribution) Number of metering stations Measured quantities (TWh) , ,92 Border stations End users stations Border stations End users stations Measurement uncertainty in a border station results in a financial uncertainty!

8 1. Who is Fluxys? 2. Fluxys Border Stations 3. Metrological Maintenance 4. Conclusion

9 GENERAL PRINCIPLE OF FLUXYS BORDER STATIONS Multi-line Measuring System to ensure operational flexibility The meter runs are ideally located between separate collectors Two independent Measuring Systems in series to insure reliability the average of both systems is used for invoicing purpose Two different flow meter technologies to reduce uncertainty UFM and turbine meters or two different UFM in series System A System B

10 GENERAL PRINCIPLE OF A METER RUN UFM 1 Turbine or UFM 2 Entry valve 3D spool fitting, if needed, a conical filter to protect the turbine meter or a flow conditioner 2D spool to withdraw the conical filter or the flow conditioner 10D upstream pipe without flow conditioner 3D ultrasonic flow meter (UFM) 11D pipe with an insulated box containing the pressure transducers 10D upstream pipe including, if needed, a flow conditioner 3D turbine flow meter or UFM 11D pipe with sampling for gas chromatographs and ancillary measurements Exit valve 10 D 11 D 10 D 11 D

11 SPECIFICS FOR ULTRASONIC METERS Calibration of the UFM package Installation with the same run configuration Meter run carefully insulated in the field Thermal insulation of the piping and of the temperature transducer is important! UFM calibration with its 10D upstream pipe and 5D downstream pipe The same meter installed in the border station with the same run configuration and carefully insulated 11

12 SELECTED METER TECHNOLOGY Turbine meters are most widely used in Fluxys border stations > Approved and tested by both partners > High repeatability and reproducibility > Long term stability Ultrasonic meters are now used in series > Low pressure loss > No moving part > Higher capacity > Self diagnosis Two different flow meters type in series are a MUST!

13 ADVANTAGE OF THE UFM IN TERMS OF PRESSURE LOSS Example for a Fluxys meter run 10 D 11 D 10 D 11 D Turbine Turbine - Before: 1096 mbar UFM Turbine - After: 693 mbar Reducing the pressure loss in a border station allows to increase the capacity of the pipeline and/or to limit compression costs

14 1. Who is Fluxys? 2. Fluxys Border Stations 3. Metrological Maintenance 4. Conclusion

15 METROLOGICAL MAINTENANCE Three levels can be identified 1. Online monitoring 2. Offline (Daily) monitoring 3. Periodic verifications IN Off-line Monitoring Bundle System A System B On-Line Monitoring + Metrological Maintenance On-Line Monitoring + Metrological Maintenance OUT

16 METROLOGICAL MAINTENANCE 1. Online Monitoring Using a multiline flow computer (developed by Fluxys) Comparison of the meter run in // No measure is taken into account without verification Performed permanently and automatically Line coefficient as key indicator IN Off-line Monitoring Bundle System A System B On-Line Monitoring + Metrological Maintenance On-Line Monitoring + Metrological Maintenance OUT

17 KEY INDICATOR FOR ULTRASONIC METERS IN // Line coefficient Vl N calculated using the equation Cij = Vtot. monitor the stability of the flow distribution generate warning and replacement value l Where: C ij is the line coefficient V l is the volume transited via a given line N l is the number of lines in operation in // V tot is the volume transited by all lines in operation in //

18 METROLOGICAL MAINTENANCE 2. Offline (Daily) Monitoring Check that measurements recorded by system A are consistent with those recorded by system B The difference between two meters in series should be less than 0.35% The difference between two independent systems should be less than 0.1% IN Off-line Monitoring Bundle System A System B On-Line Monitoring + Metrological Maintenance On-Line Monitoring + Metrological Maintenance OUT

19 METROLOGICAL MAINTENANCE 2. Offline (Daily) Monitoring Typical results between two stations in series

20 METROLOGICAL MAINTENANCE 3. Periodic verifications of P, T and GC Initial calibration by an accredited laboratory (ISO 17025) Periodic verification on site of the GC, P and T transmitters against traceable references A maximum permissible error is defined by: MPE = U ref U meas IN Off-line Monitoring Bundle System A System B Example for P or T Uref Umeas MPE 0.05% 0.10% 0.11% On-Line Monitoring + Metrological Maintenance On-Line Monitoring + Metrological Maintenance OUT

21 METROLOGICAL MAINTENANCE Calibration of the flow meters Initial calibration by an harmonized and accredited laboratory (ISO 17025) Periodic recalibration of the turbine meters (as-found + as-left) Conditions-based recalibration for UFM (as-found = as-left) Calibration TCC 2013 Calibration FORCE D 11 D 10 D 11 D Example of an as-found calibration results Dev.(%) vs. Flow (m³/h): Notice meter still in perfect state Average weighted difference: -0.09% Annual drift: 0.01% It is crucial that two meters in series on the same meter run are never replaced at the same time!

22 WHY A HARMONIZED LABORATORY? Low uncertainty (<0.2%) No systematic difference between the labs Proven long term stability Diversification of calibration labs U lab1 U lab2 U lab3 0,35% 0,30% 0,25% W lab1 W lab2 W lab3 0,231 0,315 0,454 U tot: 0,17% Choice of the lower uncertainty Frequent comparisons between labs and proved long term stability

23 SPECIFICS FOR ULTRASONIC METERS Calibration close to the field conditions» Natural gas, P, T, piping... Record and analysis of the log files» Optimize parameters if necessary (P, T, detection settings...) Linearization of the meter output» Including geometry correction for P and T We need efficient communication between labs and manufacturers to apply the right calibration, linearization and geometry correction procedure.

24 SPECIFICS FOR ULTRASONIC METERS The diagnosis allows to detect a problem in the field Velocity of sound (also to compare with GC) AGC / SN ratio (health of electronics) Flow profile (also to compare with the calibration) Performance... It is crucial to compare the main indicators recorded during calibration with those recorded in the field. The onsite footprint without the lab footprint is insufficient!

25 SPECIFICS FOR ULTRASONIC METERS But a problem can also occur during the (re)calibration» Significant difference between the VOS measured by the meter and calculated by the GC» Transducer damaged during transport or by depressurization» Poor repeatability U tot = CMC² + repeatability² A significant difference between the CMC and the Utot is suspicious. A one stop shop is ideal for repairs, calibration and optimization of the UFM, including software upgrade, replacement of the battery and transducers etc. A problem during calibration is costly!

26 1. Who is Fluxys? 2. Fluxys Border Stations 3. Metrological Maintenance 4. Conclusion

27 WRAP-UP A gas balance close to zero over time is a major concern for Fluxys Belgium or others TSOs o Low uncertainty measurement in large border stations is crucial o Stringent metrological maintenance is a must The correct use of UFM in the border stations is advantageous o Two different principles of measurement in series reduce uncertainty o Low pressure loss can increase the capacity of the pipeline and/or limit compression costs Periodic or condition-based recalibration is often the only way of checking gas meters and maintaining steady metrological performance levels o Calibration labs that are traceable through the Harmonized European Cubic Meter of Gas represent a major progress in guarantying, reduced uncertainty, stable results, fair gas trading 27

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