Large Meter Condition Assessment Using AMI Data City of Toronto. Carlo Casale Jeff Coulson Claude Williams

Transcription

1 Large Meter Condition Assessment Using AMI Data City of Toronto Carlo Casale Jeff Coulson Claude Williams 1

2 Agenda 1. Project Goals 2. Measuring Accuracy 3. Visual Inspection 4. Condition Assessment from Hourly Data 5. Meter Failure Modes 6. Maintenance Triggers 7. Questions

3 PROJECT GOALS

4 Large Meter Condition Assessment Goals Preliminary investigation into performance of large meters Use hourly flow readings from AMI Determine revenue impact of large meters not replaced during the main project Determine methods for prioritizing large meters for repair or replacement 4

5 Determining Meter Condition Perform an accuracy test Visually inspect the meter See if hourly data shows meter condition 5

6 MEASURING ACCURACY 6

7 In situ Tests Options for Measuring Accuracy Uses same piping configuration Meter is in actual operating condition Cannot always get good meter isolation Bench Tests Controlled test conditions About 1/3 cost of in situ Meter may not be in same condition or piping configuration during test Consumption (Before/After) Meter Replacement/Repair Actual revenue gain/loss Average accuracy over actual flow range and time Change in customer habits not known 7

8 Bench Test & In-Situ Test Comparison 140.0% Bench Test Results vs In-Situ Test Results at L % Bench Test Meter Accuracy 100.0% 80.0% 60.0% 40.0% 20.0% 0.0% 0.0% 20.0% 40.0% 60.0% 80.0% 100.0% 120.0% In-situ Test Meter Accuracy. In Situ Tests average about 27.6% less than Bench Tests (not including in situ test with failed valves) (not including bench tests with no low flow) 8

9 Bench Test & In-Situ Test Comparison 120.0% Bench Test Results vs In-Situ Test Results at L % Bench Test Meter Accuracy 80.0% 60.0% 40.0% 20.0% 0.0% 0.0% 20.0% 40.0% 60.0% 80.0% 100.0% 120.0% In-situ Test Meter Accuracy. In Situ Tests average about 7.8% less than Bench Tests (not including in situ test with failed valves) (not including bench tests with no low flow) 9

10 Bench Test & In-Situ Test Comparison 140.0% Bench Test Results vs In-Situ Test Results at CO % Bench Test Meter Accuracy 100.0% 80.0% 60.0% 40.0% 20.0% 0.0% 0.0% 20.0% 40.0% 60.0% 80.0% 100.0% 120.0% In-situ Test Meter Accuracy. In Situ Tests average about 2.8% less than Bench Tests (not including in situ test with failed valves) (not including bench test with no low flow) 10

11 Bench Test & In-Situ Test Comparison 140.0% Bench Test Results vs In-Situ Test Results at CO % Bench Test Meter Accuracy 100.0% 80.0% 60.0% 40.0% 20.0% 0.0% 0.0% 20.0% 40.0% 60.0% 80.0% 100.0% 120.0% In-situ Test Meter Accuracy. In Situ Tests average about 4.3% more than Bench Tests (not including in situ test with failed valves) 11

12 Bench Test & In-Situ Test Comparison 120.0% Bench Test Results vs In-Situ Test Results at I 100.0% Bench Test Meter Accuracy 80.0% 60.0% 40.0% 20.0% 0.0% 0.0% 20.0% 40.0% 60.0% 80.0% 100.0% 120.0% In-situ Test Meter Accuracy. In Situ Tests average about 0.5% less than Bench Tests (not including in situ test with failed valves) 12

13 Bench Test & In-Situ Test Comparison 120.0% Bench Test Results vs In-Situ Test Results at H 100.0% Bench Test Meter Accuracy 80.0% 60.0% 40.0% 20.0% 0.0% 0.0% 20.0% 40.0% 60.0% 80.0% 100.0% 120.0% 140.0% In-situ Test Meter Accuracy. In Situ Tests average about 0.9% more than Bench Tests (not including in situ test with failed valves) 13

14 Options for Meter Accuracy Measurements Meter accuracy over full range of meter Gives complete view of meter condition Use test results without making assumptions on usage Hard to compare meters Not useful for determining revenue impact Meter accuracy over actual range of operation Gives view of meter condition that impacts revenue Use flow-weighted accuracy Need to determine actual flow profile 14

15 Flow Profiles of Actual Meter Operation Graph of hourly consumption by percentile Increments of 10% of readings Readings not corrected for meter accuracy Recommendations Use to estimate revenue impact for each meter Revenue loss Revenue gain Use as part of meter sizing review Top end of profile should be 50% - 75% of meter capability 15

16 Flow Profile for Moderate Consumption " Compound: Neptune Flow Profile M Cubic Meters/Hour Hco Lco % 20% 40% 60% 80% 100% 120% Consumption Percentile L 16

17 Flow Profile for Low Consumption " Compound: Neptune Flow Profile Cubic Meters/Hour Hco Lco L % 20% 40% 60% 80% 100% 120% Consumption Percentile 17

18 Flow Profile for Very Low Consumption " Compound: Neptune Flow Profile Cubic Meters/Hour L % 20% 40% 60% 80% 100% 120% Consumption Percentile 18

19 Bench Test vs In-Situ at Actual Flow Profile 140.0% Bench Test Results vs In-Situ Test Results 120.0% Bench Test Meter Accuracy 100.0% 80.0% 60.0% 40.0% 20.0% 0.0% 0.0% 20.0% 40.0% 60.0% 80.0% 100.0% 120.0% In-situ Test Meter Accuracy. In Situ results show about 0.6% less consumption than Bench Tests (not including in situ test with failed valves) 19

20 Bench Test & In-Situ at Actual Flow Profile Accuracy vs Before/After Consumption 140.0% 120.0% 100.0% Meter Accuracy 80.0% 60.0% 40.0% Bench Test Site Test 20.0% 0.0% 0% 20% 40% 60% 80% 100% 120% Before/After Replacement Consumption In Situ Tests average about 6% less than Before/After Bench Tests average about 2 % less than Before/After Neither Test is reliable for an individual meter (Std Dev ~ 24%) 20

21 Recommendations on Meter Accuracy Need to do more research on meter test method and usefulness. At this point indications are: Do not test in the field not suitable for maintenance Bench test all replaced meters Develop procedure to measure accuracy of test results Report Before and After consumption (+/- 120days) Include meter age, meter throughput, bench test results All meter sizes 21

22 VISUAL INSPECTION 22

23 54% overall accuracy in operating range 23

24 54% overall accuracy in operating range 24

25 54% overall accuracy in operating range 25

26 54% overall accuracy in operating range 26

27 Visual Inspection Deposits on meter parts noted for most meters Lots of calcium carbonate buildup everywhere, especially in the strainer basket, on the turbine blades and in the PD disk. Minimal silt in turbine chamber. Deposits on meter parts A very important factor in meter condition Wear observed in some meters 27

28 CONDITION ASSESSMENT FROM HOURLY DATA High/Total Flow Performance 28

29 Low-side/Total Flow Ratio Performance Curves for Compound Meters Performance of meters is shown in low-side/total flow ratio performance curves. Usually the curves show a change in meter performance Sometimes the curves are inconclusive Failures in the low-side (PD) meter are detectable 29

30 Low-side vs Total Meter Flow 94% overall accuracy in operating range Low Side Flow (m 3 /hour) " Compound: Neptune Low Side/Total Flow Rate CO2 I Total Flow (m 3 /hour) 100% 80% Throttling valve not closing part of the time 99% Meter Accuracy Does reading data indicate meter performance? 30

31 Low-side vs Total Meter Flow 97% overall accuracy in operating range " Compound: Neptune Low Side/Total Flow Rate Low Side Flow (cubic meters/hour) L2 CO % Total Flow (cubic meters/hour) Low-side is stopping in some intervals 104% Meter Accuracy Does reading data indicate meter performance? 31

32 115% overall accuracy in operating range Low Side Flow (cubic meters/hour) Low-side vs Total Meter Flow 3" Neptune Low Side/Total Flow Rate CO % 120% CO2 Total Flow (cubic meters/hour) 90% Meter Accuracy Does reading data indicate meter performance?

33 High/Total Flow Ratio Performance Curves for Compound Meters Performance of large meters is shown in high/total flow ratio performance curves. Usually the curves show a change in meter performance Sometimes the curves are inconclusive Calculated crossover to quantify changes in performance Increase in crossover: PD is increasing its registration Decrease in crossover: PD is decreasing its registration 33

34 99.5% overall accuracy in operating range High Side Flow (m 3 /hour) " Compound: Neptune High Side/Total Flow Rate Total Flow (m 3 /hour) Year Slope Intercept Crossover Crossover Change % % %

35 Flow Rate at Crossover Indicates Condition? 101.8% overall accuracy in operating range High Side Flow (m 3 /hour) " Compound: Neptune High Side/Total Flow Rate Year Crossover Total Flow (m 3 /hour) Crossover occurs at about 3.0m 3 /hour Little change in performance meter is okay? 35

36 What does change in crossover mean? 101% overall accuracy in operating range " Neptune High Side/Total Flow Rate High Side Flow (m 3 /hour) Total Flow (m 3 /hour) Flow rate at crossover decreases from 2013 to 2014 No change 2014 to

37 METER FAILURE MODES 37

38 Deposits on Meter Parts Over time calcium and magnesium carbonates build up on PD meter parts causing inaccuracy Tolerances between the disc and static parts reduce, and accretion on disc reduces volume passed, causing over registration As tolerances reduce, friction on the disc increases causing an increase in pressure drop Ultimately, the disc seizes. Wear of meter parts and carbonate deposits increases tolerances, eventually reversing the trend in meter accuracy 38

39 Deposits on Meter Parts Over time calcium and magnesium carbonates build up on turbine meter parts causing inaccuracy Spacing between blades reduce increasing water velocity, and blade surface roughness increases, causing over registration As accretion builds in the throat of the turbine, the blades rub against it, slowing the turbine reducing sensitivity and accuracy. Ultimately, the turbine seizes. Wear of meter turbine bearings, slow turbine rotation also reducing meter accuracy 39

40 Possible Failed States (not including cutover performance) HIGH SIDE Fail Fast High Fail Fast Low Fail Slow High Side Fast Both Fail Fast Pass Low Side Slow Both Pass Low Side Fast Fail Slow Both Fail Slow High Side Slow High Fail Slow Low Fail Fast Fail Slow Pass LOW SIDE Fail Fast 40

41 Possible Failed States (not including cutover performance) HIGH SIDE 58% Fail Fast 32% High Fail Fast Low Fail Slow 10% High Side Fast 16% Both Fail Fast 28% Pass 12% 4% Both Low Side Slow Pass 12% Low Side Fast 14% Fail Slow 10% Both Fail Slow 3% High Side Slow 1% High Fail Slow Low Fail Fast Fail Slow Pass Fail Fast 54% 17% 29% LOW SIDE 41

42 Meter Failure Modes Conclusion Deposition on meters is likely the cause of most performance issues for Toronto. Likely applicable to other water supplies with significant hardness Deposition obscured other causes of failure Need to devise a method of assessment to reveal other causes of failure Need to test other water supplies 42

43 MAINTENANCE TRIGGERS 43

44 Maintenance Triggers Develop maintenance triggers Based on how failures occur Based on data of meter operation Prefer AMI data rather than on-site condition measurement Use triggers to target maintenance on meters Maintain or replace when required (to reduce costs and maximize revenue) Move from calendar or odometer intervals to condition-based scheduling 44

45 Meter Age Accuracy vs Meter Age 140.0% 120.0% Meter Accuracy 100.0% 80.0% 60.0% 40.0% Bench Test Site Test 20.0% 0.0% Meter Age Pilot only looked at meters with roughly the same age. Therefore no conclusion possible 45

46 Total Meter Throughput 140.0% Accuracy vs Meter Throughput (m3) 120.0% Meter Accuracy 100.0% 80.0% 60.0% 40.0% Bench Test Site Test 20.0% 0.0% - 500,000 1,000,000 1,500,000 2,000,000 2,500,000 3,000,000 Total Meter Consumption Most significant meter failures occur after a threshold of approximately 600,000m 3 46

47 Drop in Consumption Account Monthly Usage (m 3 ) Old Meter New Meter Jan-13 Mar-13 May-13 Jul-13 Sep-13 Nov-13 Jan-14 Mar-14 May-14 Jul-14 Large Drop in consumption mostly change in consumer habits (Coronation St) Sep-14 Nov-14 Jan-15 Mar-15 May-15 Jul-15 Sep-15 Nov-15 Jan-16 Mar-16 May-16 47

48 Recommendation for Drop in Consumption List all large meters with consumption drop of more than 15% in one month or more than 20% in two months. Report low side, high side and total. Replace all meters on list 48

49 Recommendation for Low-Side Stops 2.5 3" Meter: Low/Total Flow Low Side Flow Rate (m3/hr) Total Meter Flow Rate (m3/hr) Repair or Replace within one year 49

50 Recommendations for throttling valve failure 7000 Account Monthly Usage (m 3 ) Old: Low Old: High Old Total 0 New: Low New: High New: Total Jan-13 Mar-13 May-13 Jul-13 Sep-13 Nov-13 Jan-14 Mar-14 May-14 Jul-14 Sep-14 Nov-14 Jan-15 Mar-15 May-15 Jul-15 Sep-15 Nov-15 Jan-16 Mar-16 May-16 Jul-16 Repair or Replace within one year 50

51 Maintenance Trigger Summary Factors that correlate well with accuracy Large drops in consumption Factors that do not correlate well with accuracy, but should still be used to plan maintenance Meter age Meter throughput (life) Low side stops Stuck throttling valves Not enough data to make a decision: Annual change in calculated crossover Shift in the flow profile 51

52 Questions? Carlo Casale Jeff Coulson 52