ESP Avanced Diagnostics - Wpca.info

Worldwide PollutionControl AssociationFirstEnergy ESP SeminarNovember 27 th –28 th , 2007Visit our website at www.wpca.info

Advanced ElectrostaticPrecipitator DiagnosticsGE EnergyJohn A. Knapik

Does This ESP Have A Problem?GEProprietary2

How Can One Easily Tell?GEProprietary3

This Leads Us to...A Step by Step Analysis forDiagnosing a MisbehavingESP

That data was for an ESP that had:(2) Boxes, American Style ESP(4) Fields(4) T-R Sets Per Field(16) T-R Sets Per Box(2) Lungstrom Air HeatersBurning High Sulfur CoalGEProprietary5

First Step:Put Your Data in a Form YouCan Easily Visualize

Put T-R Sets in an ESP Plan View4B2 4B1 8B2 8B1 T/R SETS 4A2 4A1 8A2 8A13B2 3B1 7B2 7B1 3A2 3A1 7A2 7A12B2 2B1 6B2 6B1 2A2 2A1 6A2 6A11B2 1B1 5B2 5B1 1A2 1A1 5A2 5A11299 836 622 347 MILLIAMP 193 404 1124 1400757 700 572 419 211 450 492 350436 Next 252 show 287 175 your meter 149 readings.333 470 622375 OFF 104 157 OFF 150 235 501But what AVC meters should you use?14 15 15 14 SPM 14 11 6 118 13 18 17 12 11 16 2022 18 14 17 14 11 15 1130 OFF 30 27 OFF 28 27 25GEProprietaryGas Flow7

GEProprietary8

What Is the Best AVC Meter toUse to Evaluate an ESP Field?The Milliamp Meter

Put Data in an ESP View4B2 4B1 8B2 8B1 T/ R SETS 4A2 4A1 8A2 8A13B2 3B1 7B2 7B1 3A2 3A1 7A2 7A12B2 2B1 6B2 6B1 2A2 2A1 6A2 6A11B2 1B1 5B2 5B1 1A2 1A1 5A2 5A11299 836 622 347 MILLIAMP 193 404 1124 1400757 700 572 419 211 450 492 350436 252 287 175 149 333 470 622375 OFF 104 157 OFF 150 235 501Gas FlowGEProprietary10

Which Meter Next?The Spark Meter

Put Data in an ESP View4B2 4B1 8B2 8B1 T/ R SETS 4A2 4A1 8A2 8A13B2 3B1 7B2 7B1 3A2 3A1 7A2 7A12B2 2B1 6B2 6B1 2A2 2A1 6A2 6A11B2 1B1 5B2 5B1 1A2 1A1 5A2 5A11299 836 622 347 MILLIAMP 193 404 1124 1400757 700 572 419 211 450 492 350436 252 287 175 149 333 470 622375 OFF 104 157 OFF 150 235 50114 15 15 14 SPM 14 11 6 118 13 18 17 12 11 16 2022 18 14 17 14 11 15 1130 OFF 30 27 OFF 28 27 25GEProprietaryGas Flow12

What About the KV Meter?Can Be Tricky!I’ll Explain Later.

Step 2If a T/R set is not sparking, then its AVCshould be pushing that T/R set to one of itspre-set limits (volts, amps, KV, or ma)GEProprietary14

Again, know the ratings of the T/Rsets on the ESP being reviewed.Here’s How to Do That.

Walk up to the roof ofthe ESP and look atthe nameplate on theT/R setGEProprietary16

One T/R Running with “No” Sparking1600 1600 1600 1600 T/ R SIZE 1600 1600 1600 16001400 1400 1400 1400 1400 1400 1400 14001250 1250 1250 1250 1250 1250 1250 1250950 950 950 950 950 950 950 9501299 836 622 347 MILLIAMP 193 404 1124 1400757 700 572 419 211 450 492 350436 252 287 175 149 333 470 622375 OFF 104 157 OFF 150 235 50114 15 15 14 SPM 14 11 6 118 13 18 17 12 11 16 2022 18 14 17 14 11 15 1130 OFF 30 27 OFF 28 27 25Is it at a limit?GEProprietary17

Check to see if T/R is at limit. The mA valueson the previous page were average values.Looking closer we findVALUES AMPS VOLTS mA KV SPMT-R RATING 214 480 1600 45ACTUAL 215 365 1517 39.7 1AVERAGE 198 246 1400 37.7 5VALUES AMPS VOLTS mA KV SPMT-R RATING 214 480 1600 45ACTUAL 215 365 1517 39.7 1AVERAGE 198 246 1400 37.7 5Yes, the T/R is primary amp limitedGEProprietary18

Step 33. Each succeeding field of a precipitatorshould have the same or higherprecipitator current (mA), better said ascurrent density, than the preceding field.GEProprietary19

Incremental Collection Efficiencyand Secondary Operating ConditionsKVmASPMVoltage ControlReadingsInlet Middle Outlet80% 70% 60%Gas Flow100#20# 6# 2.4#80# 14# 3.6#To the StackGiven:100# entering ESPAssume:Each field collects as shownEfficiency:97.6%80# 94# 97.6#Values shown are to represent relationship only...not necessarily actual conditionsGEProprietary20

Space Charge Effects on MetersAlways look forthis trend...Inlet Middle OutletmADecreasing KV andSPM from inlet tooutlet is not quite asevidentInlet Middle OutletKV & SPMGEProprietary21

Applying Step 3, we get:Gas Flow1299 836 622 347 MILLIAMP 193 404 1124 1400757 700 572 419 211 450 492 350436 252 287 175 149 333 470 622375 OFF 104 157 OFF 150 235 50114 15 15 14 SPM 14 11 6 118 13 18 17 12 11 16 2022 18 14 17 14 11 15 1130 OFF 30 27 OFF 28 27 25At first glance, probably not enough “bad”sets to cause the high opacityGEProprietary22

3-D MILLIAMP REVIEW14001299112414001200FLD 4FLD 2836757700 622622572492404 450 470350 501347419436193 333211287375235252175 1491501571040010008006004002000MILLIAMPSGEProprietary23

Step 44. If the dust is not highly resistive, then outletfields usually run at full current and little orno sparking.GEProprietary24

But These Outlet Fields Are Sparking.Should This Happen With High SulfurCoal?1600 1600 1600 1600 T/ R SIZE 1600 1600 1600 16001400 1400 1400 1400 1400 1400 1400 14001250 1250 1250 1250 1250 1250 1250 1250950 950 950 950 950 950 950 9501299 836 622 347 MILLIAMP 193 404 1124 1400757 700 572 419 211 450 492 350436 252 287 175 149 333 470 622375 OFF 104 157 OFF 150 235 501GEProprietary14 15 15 14 SPM 14 11 6 118 13 18 17 12 11 16 2022 18 14 17 14 11 15 1130 OFF 30 27 OFF 28 27 25Maybe the dust is resistive?This one is tricky!25

Wouldn’t Hurt to Run a Couple ofQuick V-I CurvesThese are quick tests forresistivity. A full curve may beprohibitive because of opacityspiking caused by backing a setdown to corona onset. Be careful!

If the Dust is Conductive, then theCurve should Slope to the Right.Example:++GEProprietary27

If the Dust is Resistive, then the Curvewill be Vertical or Slope to the Left.Example:GEProprietary28

Running a “Quick VI Curve would Yield:GEProprietary29

Unfortunately, No V-i CurvesWere Run at the Time forThis ESP. So, Let’s SeeWhat Else Might Be Helpful.

Step 55. Current densities are the best tool to checkfor dust resistivity and to comparesuccessive fields’ current (mA) values.GEProprietary31

Current Density

Current Density1. Enables A true comparison of ESP currentfor T/R sets not energizing the samesquare feet of collecting plates.2. Generally accepted values for low and highresistivity dust, can aid in troubleshooting.GEProprietary33

Based on what we learned in Step 3,this ESP is OK. However, that wouldbe…..20 G.P. Gas FlowAT/R Set500Field 1200 mA6’ x 20’BT/R Set500Field 2250 mA9’ x 20’WRONG!GEProprietary34

Current Density20 G.P. Gas FlowAT/R Set500Field 1(41 µA/ft 2 )6’ x 20’200 mA200÷ 20 G.P. x 6’ x 20’ x 2 sides = 41 µA/ft 2BT/R Set500Field 2(35 µA/ft 2 )9’ x 20’250÷ 20 G.P. x 9’ x 20’ x 2 sides = 35 µA/ft 2250 mA(Lower than the first field!)GEProprietary35

I. Current Densities (for conductivedust)In general, typical range of values for currentdensity for a four fieldAmerican ESPCurrent DensityField Number (µA/ft 2 )1 15 - 252 25 - 403 40 - 604 60 - 80GEProprietary36

I. Current Densities (for conductivedust)In general, typical range of values for current densityfor a four field European ESP where T-R sets maynot be sized to provide more than 40µA/ft 2Current DensityField Number (µA/ft 2 )1 10 - 202 20 - 303 30 - 404 30 - 40GEProprietary37

II. Current Densities (for high resistivitydust)GEProprietaryTypical values of current density for highresistivity but no Back Corona.Current DensityField Number (µA/ft 2 )1 7 - 252 7 - 253 7 - 254 7 - 25(Accompanied by sparking in allfields)38

III. Current Densities (an example of highresistivity in fields 2 and 3 and stable backcorona in the 4 th field)Current DensityField Number (µA/ft 2 )1 212 203 194 72Don’t be fooled by useless current!GEProprietary39

Back Corona – Non Useful Current!1100(18kv,1100mA)T = PPTRCurrentMilliamps900700500Grounded HighVoltage ElectrodeSevere BackCoronaModerate BackCorona(27kv, 490mA)Dust Deposits onHigh Voltage Electrode300MisalignmentSPARKSPARKSPARKModerately HighAsh Resistivity10000 10 20 30 40 50GEProprietaryV = PPTR Voltage KV40

Converting to Densities we get:1299 836 622 347 MILLIAMP 193 404 1124 1400757 700 572 419 211 450 492 350436 252 287 175 149 333 470 622375 OFF 104 157 OFF 150 235 501109 70 52 29 DENSITY 16 34 95 11864 59 48 35 18 38 41 2937 21 24 15 13 28 40 5232 OFF 9 13 OFF 13 20 42GEProprietary41

Evaluating Densities We Get:1299 836 622 347 MILLIAMP 193 404 1124 1400757 700 572 419 211 450 492 350436 252 287 175 149 333 470 622375 OFF 104 157 OFF 150 235 501109 70 52 29 60 - 80 16 34 95 11864 59 48 35 40 - 60 18 38 41 2937 21 24 15 25 - 40 13 28 40 5232 OFF 9 13 15 -25 OFF 13 20 42There appears to be a pattern here. Why?GEProprietary42

Step3 vs. Step 5 Comparison1299 836 622 347 MILLIAMP 193 404 1124 1400757 700 572 419 211 450 492 350436 252 287 175 149 333 470 622375 OFF 104 157 OFF 150 235 501Step 3Notice how many more “substandard” fields areidentified by applying Step 5109 70 52 29 60 - 80 16 34 95 11864 59 48 35 40 - 60 18 38 41 2937 21 24 15 25 - 40 13 28 40 5232 OFF 9 13 15 -25 OFF 13 20 42Step 5GEProprietary43

Get the point?GEProprietary44

Looking at things again:1299 836 622 347 MILLIAMP 193 404 1124 1400757 700 572 419 211 450 492 350436 252 287 175 149 333 470 622375 OFF 104 157 OFF 150 235 501109 70 52 29 60 - 80 16 34 95 11864 59 48 35 40 - 60 18 38 41 2937 21 24 15 25 - 40 13 28 40 5232 OFF 9 13 15 -25 OFF 13 20 42There appears to be a pattern here. Why?GEProprietary45

109643732705921OFF524824929351513161813OFF3438281395414020118295242GEProprietary46Graphic Visualization

Densities also explain why there was sparkingin outlet fields on the conductive side109 70 52 29 60 - 80 16 34 95 11864 59 48 35 40 - 60 18 38 41 2937 21 24 15 25 - 40 13 28 40 5232 OFF 9 13 15 -25 OFF 13 20 4214 15 15 14 SPM 14 11 6 118 13 18 17 12 11 16 2022 18 14 17 14 11 15 1130 OFF 30 27 OFF 28 27 25The T/R sets are oversized. They provide morecurrentthan required. Their quantity had been doubled.GEProprietary47

Step 66. T/R sets in the same relative field positionshould run at the same power levels, bothvoltage (kV) and current (mA)GEProprietary48

9A,10A, 16A RUNNING PROPERLY. 13A JUST SLIGHTLY OFF.SEEING HOW THESE RUN ENABLE AN ANALYTICAL REVIEWOF 15AGEProprietary49

Applying Step 6 we get:1299 836 622 347 MILLIAMP 193 404 1124 1400757 700 572 419 211 450 492 350436 252 287 175 149 333 470 622375 OFF 104 157 OFF 150 235 501Step 6 can achieve the same results as adensity review and is simpler,but not as precise.GEProprietary50

With just numbers, we were nowhere.GEProprietary51

Now After Applying 6 Steps, We CanPlan a Strategy.52109643732705921OFF524824929351513161813OFF3438281395414020118295242GEProprietary

Questions?Thank you.