2013 Honeywell Users Group Europe, Middle East and Africa. Jürgen Wolff Advanced Gas Metering through Flow Profile Analysis

Transcription

1 2013 Honeywell Users Group Europe, Middle East and Africa Jürgen Wolff Advanced Gas Metering through Flow Profile Analysis 1

2 Agenda Introduction to RMG by Honeywell s ultrasonic meter USZ08 The diagnostic approach Measurement disturbances Flow profile analysis Conclusions 2

3 RMG Ultrasonic Gas Meter USZ 08 Available Sizes 4 (DN100) to 40 (DN 1000) ANSI 150 to ANSI 900 (ANSI 2500) PN 10/16 to PN 100 Measurement uncertainty of ±0.1% 6-Path-technolgy Direct measurement Crossed paths in one plane Measurement capability 3D Flow profile modeling Turn down ratios up to120 : 1 Approx. 40 m/s max. gas velocity Bidirectional Measurement Sensor technology Fully encapsulated Titanium sensors EEx-d ( high voltage, high energy) Operational pressure barg Calibration / verification Dry calibration at static pressure Flow calibration at atmospheric pressure up to m 3 /h High pressure calibration (Optional) 3

4 4 Calibration Test Results USZ08 Bidirectional

5 5 Calibration Test Results USZ08 Bidirectional

6 History of RMG Ultrasonic Meters Market launch of the USZ 08 with sensors from Panametrics First approval for fiscal metering in Germany Meter electronics combined in one Ex-d housing Introduction of own RMG designed ultrasonic sensors New controller type USE 09-C incl. Display and Modbus + MID approval New design for global use FM, CSA, ATEX, IEC-Ex approvals 6

7 USZ08 - Paths Arrangement Arrangement of paths and planes according Gauß-Chebyshev Functional principle of the USZ 08 6 paths 12 sensors 2 crossed paths per plane 3 planes, 1 central + 2 symmetrical 7

8 Paths Arrangement By measurement of crossed paths the optimized detection of velocity components v 1,, v 6 is ensured, even for asymmetric flow profiles, swirl or transversal flow and represents the average total velocity (v * ) though the pipe cross section (A). Q A v A ( w v w ) v w = weighting 8

9 Paths Arrangement Measurement of Velocity Z Vz X Axial flow velocity Z Vz Z X Vx Total flow velocity X Vx Tangential flow velocity 9

10 Paths Arrangement Measurement of Swirl Z Vz X Vx Upper plane Center plane Lower plane 10

11 11 Installation Examples

12 12 Installation Examples

13 13 Installation Examples

14 14 Installation Examples

15 Why Diagnostics? Standards and compliance through typetesting is critical to quality and the minimum entry requirement to market Ensure accuracy of the operational metering system: Prove your metering is accurate throughout its useful life-cycle Ideally signal when operational accuracy is affected, caused by process condition or metering defect 15

16 USM Diagnostics Overall Approach Measurements Fluid velocity Pressure Temperature Transit times Path velocities Delta times Processing (Diagnostics) SNR VoS to AGA 10 Asymmetry Profile factors Swirl angle Performance Turbulence Inference Engine Performs analysis to infer the fault and its source Mostly manual Early tech trend new method in ANN* * ANN: Artificial Neural Networks Key Observations Most manufacturers provide similar diagnostic methods Inference based on various parameters is mostly done by experts Future trends Inference tools are emerging as key trends, e.g. Artificial Neural Networks Enhancing inference engine to reflect clear maintenance action 16

17 Reasons for Measurement Disturbances Ultrasonic noise Regulator Flow conditoner Bad flow profile Inlet pipe configuration (station design) Change of the flow profile during operation Liquids or dirt in the gas Partly blockage of a flow conditioner Not fully opened ball valve Wrong aligned gasket after service 17

18 db Amplitude Regulator Noise Signal to Noise - Ratio 120kHz 200kHz Noise generated by regulator >340kHz f [Hz] 18

19 Regulator Noise Test Setup Test setup at HDV Lintorf: USZ08, DN 300 (12 ) Regulator RMG 530 Regulator RMG 530, DN 300 PTB Flow Straightener Plate USZ 08 Ultrasonic Meter Microphone Kötter transmitters for the detection of ultrasonic regulator noise A microphone for audible sound 19

20 Regulator Noise Test Setup Test setup of regulator and USM with sound transmitter of Kötter Consulting Engineers 20

21 Regulator Noise Signal Detection and Analysis Raw Signal of path 1 in up- and downstream direction After signal preparation even hardly visible ultrasonic signal with very bad signal to noise ratios can be detected and analyzed 21

22 Regulator Noise Test Results Result without special signal preparation 22

23 Detection of Disturbances through CBM CBM = Condition Based Monitoring Possibilities: Monitoring of the AGC levels (signal amplification) Comparison of the Velocity of Sound (VoS) of each path Signal quality Signal to noise ratio (SNR) in db Valid samples in % Comparison of the Velocity of Sound (VoS) due to AGA 10 Estimated velocity of sound from the composition of the natural gas Measured velocity of sound from the ultrasonic meter Evaluation of the flow profile Comparison of Flow Profile Factors Monitoring the swirl angle φ Live - RMG Precision Adjustment 23

24 Velocity of Sound Comparison of each Path The ratio of VoS of the single paths should be close to one Example: C 1 = m/s C 2 = m/s C 3 = m/s C 4 = m/s C 5 = m/s C 6 = m/s Ratio: C 1 /C 2 = C 1 /C 6 = etc. 24

25 Signal to Noise Ratio (SNR) [db] Signal-to-Noise Ratio Normal Non- Normal Every single valid measurement will be checked on SNR-limits If the lower SNR-limits are reached, this result is removed Gas Velocity [m/s] Outer Path (shows typically higher values, due to shorter distance) Center Path Typical SNRs are shown for inner and outer paths depending on the gas velocity 25

26 Mess.P,T.. Analyse Blende E/A Archiv Test Zählw erke Durchfluss Zähler Modus Typschild Ausw ahl Alarm Löschen Herst.-Nr. Herst.-J. Höchstbelastungs-Anzeigegerät ET 2000 Herst.-Nr. Ultraschallgaszähler Typ USZ ERZ 2004 Trockenes Gas im Normzustand (1,01325 bar, 0 C) Richtig bei =0 Weitere Daten: Taste "Typschild MESSTECHNIK GMBH Butzbach Funktionstaste 5 Archiv drücken. Zurück mit beliebiger Taste. Herst.-Nr RB 3 RB 3 RB 3 Live Comparison of VoS due to AGA 10 CH4 N2 Calculation of VoS CO2 C2H6 C3H8 Netz Messung Warnung Alarm Betrieb Eingabe Enter Comparison of calculated VoS with measured VoS Difference < 0.25% , *! Com-F Measurement of VoS 26

27 Flow Profile Factors X-Profile Factor Y-Profile Factor Two types of profile factors X profile factor Flow profile in the in the horizontal direction using the Sensor-Cross- Planes Y profile factor Indicates the vertical portion of the flow profile Normal conditions X = Y Disturbed conditions X Y The integral is not closed Some parts of the profile are missing Further analysis of the sub profile factors Can be tracked and displayed with the RMGView software 27

28 Flow Profile Factors Profile Factor Analysis Sub Profile Factors X and Y 28

29 Flow Profile Factors X 2 Profile Factor Profile factor X = 2 * (p3+p4) / (p1+p2+p5+p6) Profile factor X 1 = (p3+p4) / (p1+p2) Profile factor X 2 = (p3+p4) / (p5+p6) p = path velocity X 1 Profile Factor X profile factor: X 1 profile factor Comparison of center plane with upper plane X 2 profile factor Comparison of center plane with lower plane Ideal conditions: X 1 = X 2 = X 29

30 Flow Profile Factors What does this mean for real measurements? Depositions of dirt or liquid to the inner surface of the pipe Roughness of the inner surface changes Can the USZ 08 detect this disturbances? Answer is: yes The detection is done by the monitoring of the profile factors` In this case X 1 and X 2 will be increasing Level 1 Level 2 Level 3 Dirt or Roughness Dirt or Liquid 30

31 Flow Profile Factors Example for dirt on the bottom Depositions of dirt or liquid to the inner surface of the pipe In this case X 1 will stay or decrease a little but X 2 will be increasing remarkable Level 1 Level 2 Level 3 Dirt or Liquid Visualization of the profile factors with RMG View 31

32 Flow Profile Factors How can profile factors help in real world installations? Example of a gas station with USZ08, DN400 (16 ) Diagnostics results: Comparison of VoS due to AGA 10: OK Signal Quality (SNR): OK Profile factors X 1 /X 2 show a significant difference of 5% Why? Rust, mainly on the top side of the meter caused the effect! A verification of the meter on a high pressure calibration facility shows an error shift of > 0,2 % vs. the original error. After removing the rust and cleaning the error returns to the original values! 32

33 Monitoring the Swirl Angle φ Swirl Angle Difference of the gas velocity vector from the axial direction Standard conditions: The sum of the all the swirl angles should be 0 or close to If the sum of the all the swirl angles 0 The profile is not 100% captured Measured flow can be lower or higher then the real flow Ф = Swirl angle ν = Spin component of the velocity Ω = Axial velocity Level 1 (upper) Level 2 (center) Level 3 (lower) 33

34 Zero Flow Verification Test - Standard Zero Flow Verification Test Described in AGA9 Delay times appear with no flow Signal-processing electronics Transducer + cables Calculation algorithms To determine the system delay time t all other measured values of this equation have to be determined most exactly 34

35 Zero Flow Verification Test - Standard The time of flight is directly measured by the ultrasonic gas meter The path length L can be measured exactly More challenging is the determination of the theoretical speed of sound C It can be calculated by the use of state of the art algorithms (AGA8/AGA10), taking into account the gas composition and the actual gas temperature and pressure. To minimize the measurement uncertainty it is recommended to fill the meter with a gas of well known speed of sound (e.g. N2 ). Pressure and temperature have to be kept stable during the measurement and have to be measured precisely. Most critical is the measurement of the temperature, as levels of differing temperatures may occur inside of the meter. Obviously this method includes various possible sources of errors, which contribute to and increase the measurement uncertainty! 35

36 Live - RMG Precision Adjustment (Patented) Two measurements have to be done per Shot: Time of flight between S 1 and S 2 : t 1 First echo on the receive sensor: t 2 The fundamental equations are: C 1 = L / (t 1 - t w ) and C 2 = 3 * L / (t 2 t w ) C 1 = C 2 = const. (for short times) Combining and solving for tw: t w = ( 3 * t 1 t 2 ) / 2 So the delay time will be determined very precisely, shot by shot! That means LIVE! S1 L S1 3 x L v v C1, t1 S2 C2, t2 = 3 x t1 D D S2 36

37 Live - RMG Precision Adjustment This method provides following unique advantages: Gas composition, pressure and temperature must not be known The measurement is independent of the theoretical value of the velocity of sound The adjustment can take place at any time Automatic determination of the delay time Higher accuracy of VoS A verification of the meter can be performed in the field under operating conditions! Temperature, pressure, moisture, ageing of sensors and electronics have no influence of the calibration result! Standard USM Operation without tw calibration, e.g. the first factory start-up of the meter or after sensor change. USM Operation after Precision-Adjustment- Mode is switched on!! Real time dry-calibration under live conditions!! 37

38 Conclusions Ultrasonic gas meters replaces more and more traditional meters (turbine, vortex, orifice) for high volume measurement due to the ability to perform detailed diagnostics. With the analysis of the flow profile a variety of problems occurring during operation can be detected. This can lead to maintenance based on the condition of the meter / metering system and not on a fixed schedule. Cost savings for service. Keep the metering system in good health. Avoid increasing error over time. 38

39 2013 Honeywell Users Group Europe, Middle East and Africa Thank you 39 Contact: