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EHC Fluid Issues, Implications, and Opportunities for ImprovementPeter DufresneEPT/ Calgary, Canada
Matthew Hobbs, Ph.DEPT
©Copyright EPT 2017
Copyright, Peter Dufresne, EPT 2017, and other authorsas noted. This work is the intellectual property of theauthor. Permission is granted for this material to beshared for non‐commercial, educational purposes,provided that this copyright statement appears on thereproduced materials and notice is given that the copyingis by permission of the authors. No commercial use isallowed. No Re‐publishing in part or in while is allowedwithout the written permission of the author. The authorcan be contacted at [email protected]
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No Photography please.
Vorname Name – OilDoc Conference 2017
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LOCATED IN CALGARY, CANADA
OilDoc Conference 2017
Vorname Name – OilDoc Conference 2011
Copyright © EPT 2017, All rights Reserved 7
WHEN RESULTS MATTEREPT is focused on advancing the science of lubrication filtration technology.We’ve specialized for 20 years in turbine applications and have developed leading cleaning technologies that replace obsolete practices used widely in industry. We work with some of the largest turbine fleets in the world achieving unprecedented results and cost savings.
• 1000 turbines/ compressors worldwide• 50 million operating hours• $100 million proven cost savings
EPT Background
Copyright © EPT 2017, All rights Reserved 8
EPT Background
Taichung Fossil Plant, TaiwanLargest Fossil Power Plant in the World
JFK International Airport, New York City, USAOne of the Busiest Airports in the World
TransCanada1 of the Largest Fleets of Gas Turbines
Copyright © EPT 2017, All rights Reserved
Production Loss = 5000MW@ €37MW hour =€5.5 million/day
Cost Justification for Improved Maintenance
Copyright © EPT 2017, All rights Reserved
• Controls high pressure steam going to the steam turbine
• Uses high precision servo valves to control position, velocity and pressure
• For GE units, 4‐12 of Moog 743F series valves
• PM schedule is 3‐5 years
Electro Hydraulic Control (EHC) System
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Photo Courtesy of Barry Sibul and Company
Avoidable EHC fluid operating issues are frequently observed
with common parallels from site to site. These failures are costing shareholders € 100’s of millions
annually.11
Shareholders of Insurance Companiesvs Shareholders of Power Companies
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One side will win and the other will lose
The Cost of Failure can be Extreme
Sherburne County Generating StationCatastrophic failure 2012 in Unit 3 1100MW ST.Failure costs exceeded €188 million Source: MPR News, Oct 21, 2013
“Rare but not uncommon in Industry for failures of this type”– Ron Brevig, Plant Director, Xcel Sherburne County Generating Station
– Star Tribune Oct 2, 2012
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“Majority of costs will be covered by insurance”
– Ron Brevig, Plant Director, Xcel Sherburne County Generating Station
– Star Tribune Oct 2, 2012
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This loss has put all power companies in the spotlight with insurance companies starting to check lubricant and fluid quality.
Common Issues Observed
1. Power plant operators are not always following operating fluid specifications.
2. Lab Analysis is missing harmful contamination that accumulates using obsolete acid filter technology
3. Misapplication of Vacuum Dehydration
4. High pressure mechanical filters are breaking down and shedding fibers into servo‐valves
Consequences of Not FollowingSpecifications
Laguna Verge Nuclear Power Plant30 day outage from Hydraulic Failure caused from incorrect fluid maintenance in EHC system.
Loss to Company @ €37MW/h > €22 Million.
Fluid Analysis Vs OEM Limits
Property Actual Results Alstom (Limits)Ref F 26/11/08
Acid Number(D974‐64)
0.14 0.2 mg/ KOH/g replace fluid at 0.50 and before reaches 1.0
Water (D1744) 480ppm 1500ppm
Particle Count 4 7 (NAS 1638)
Viscosity +10 % of initial
ResistivityGohm‐cm
<1 x109 >4 x 109
Chlorine 87ppm 50ppm
Metals, Mg 21ppm 30ppm
Metals, Fe 4ppm 20ppm
Metals, Cu 0ppm 20ppm
Metals, other 79ppm ‐‐‐
Air Release 13 minutes 8 minutes19
Consequence
• Loss at this site was NOT considered a warranty issue as EHC fluid was outside of specification resulting in a loss to the Power Plant Owner of >€22 million
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HOW MANY SITES OPERATE OUTSIDE OF FLUID SPECIFICATION?
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Acid Number Results
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Summary of 484 EHC oil samples analyzed
Average Acid Number (AN) 0.31 mgKOH/g with 50% of sites >0.10 and 30% >0.20
Resistivity Results
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Average Resistivity 12.9 gohm-cm, yet 58% of samples fail to meet specification of >10 (GE). How is this possible?
LAB ANALYSIS IS MISSING HARMFUL CONTAMINATION THAT ACCUMULATES FROM USING OBSOLETE ACID FILTER TECHNOLOGY
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Fuller’s Earth is adding metal contamination and allowing other dissolved breakdown products to
accumulate
Source: EPT/ Dufresne
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Metals
Metals are not routinely measured
Metals are catalysts that increase fluid break-down, and create the chemical pathways from which solid deposits form
Analysis of Fuller’s Earth in H2S04 / H2O2
Evidence that Fullers Earth is a source of metal ingression in EHC fluids
Source: EPT
Why Does the Status Quo Prevail?
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“The important thing is to never stop questioning”
Albert Einstein
Dissolved ContaminationAccumulates using Fuller’s Earth
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26‐SEP‐12 04‐OCT‐12 15‐OCT‐1219‐SEP‐1229‐AUG‐12
Source: EPT
This contamination cannot be viewed with traditional oil analysis
Hexane Reveals Hidden Contamination
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NEWFYRQUEL
Source: EPT
Exelon/EPRI Deposition Tendency Test
Dissolved Contamination forms Solids
Source: GE
• Results from a nuclear power plant strongly suggests a compelling case to replace or clean fluid exists?
• No specification or regulation exists on this parameter. 32
Exelon/EPRI Deposition Tendency Test
Hexane Extraction Results‐
Source: EPT
Particulates <4umare not measured
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0.45um patches are weighed to report mass of particulates /50g of EHC fluid
<4 um particulate commonly represents >90% of the total particulate contamination in a system (by mass)
ASTM 7843 MPC Testing, step in the right direction but the dark color would report a high value which is not necessarily reflective of high varnish potential but high dirt load.
OPPORTUNITIES TO LEVERAGE TECHNOLOGY TO ELIMINATE
COMMON ISSUES34
Phosphate Ester Fluid treatment
• 1966, Schober reported successful treatment of phosphate ester by fuller’s earth.
• In Germany Grupp reported in 1971 gelatinous deposits observed which were attributed to the calcium and magnesium from the fuller’s earth
• Despite this issues, Fuller’s Earth remains widely used 50 years later.
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Schober,J., “Fire-Resistant Hydraulic Fluids”, Brown Boveri Review”, 53,12, pp 142-147 (1966)Grupp, H., “Betriebsbedingte Veränderungen von schwer entflammbaren Hydraulikflüssigkeiten undderen analytischer Nachweis”, VGB Kraftwerkstechnik, 72, 7, 630-635, 1992
Leverage Technology To Resolve Common Issues
1. Replace High Pressure Fiberglass Filters with Fiber Free Stainless Steel Filters
2. Ion Exchange Resin Filtration for acid, dissolved contamination and resistivity management.
3. Replace Vacuum Dehydration with N2 Generators
4. Electrostatics for fine particulate and color management.
HIGH PRESSURE FILTER FIBER MIGRATION
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Background
• Main EHC High Pressure pump filters on 1000MW Steam turbine plugging <30 days
• Normal operating interval 1year• Investigation….
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New vs Used Filter Inspection
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New vs Used Filter under SEM
40Source: EPT
Acid Filter Material on Filter(confirmed by XRD)
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Fuller’s Earth, a clay based adsorbing media found I the high pressure filters.
Servo Valve Strainer Plugging
42Source: EPT
Servo Valve Strainer Plugging
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Source confirmed 100% by XRD/SEM to match filter fibers in High Pressure Filters.
Source: EPT/ Dufresne
Replaced Microglass Filters with Stainless Steel Media
• Stainless Steel Filter replacements for High pressure Microglass filters used in EHC systems. – Eliminates 100% of the risk of fiber
shedding – Standardized by largest USA Nuclear
operator
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Ion Exchange Resin Technology Offers a Huge Step Forward
Replace Acid filters (with high metal ion concentration) with Engineered Ion Exchange Resin Technology (no metal content)
Source: EPT
• Contributes metals, abrasive particles • Contains no metals and actively removes metals and broader spectrum of dissolved contamination
• Several Types and Brands
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Different types of ICB depending on application:
”A” for phosphate ester maintenance. Acid and dissolved contamination removal, Resistivity improvement.
“C” for polyol ester fluid acid removal
“V” for R&O Inhibited mineral oils used in Turbine and compressor applications
“J” Media for Jet Lube Applications
Source: EPT
ICB is a trademark of EPT
Acid Removal Filters ‐ ICB™
ICB Resin TechnologyTargets the Root of the Problem
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As found 60 Reservoir 120 ReservoirMixed with Hexane Cycles with ICB Cycles with ICB
Source: EPT
Copyright © EPT 2012, All rights Reserved
• Economic case study of on fleet of 100 turbines using ICB™– Cost saving to this user of € 90 million
– Filter waste reduced by 2,300,909 Kg
– Lubricant waste reduced by 4,211,160 liters
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Background ‐ Economic Analysis
WATER REMOVAL:MISAPPLICATION OF VACUUM DEHYDRATION?
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Atmosphere is THE main source of water contamination in EHC fluids
Existing System ‐ Atmospheric Water Ingression
51Source: EPT
Vacuum Dehydration does not AddressRoute Cause of Water Ingression
52Source: EPT
KEY POINTS• Generates 99% Nitrogen
which removes all water and eliminates the fluids contact with O2
• Extremely high R.O.I.• No moving parts, no
electricity requirements• Reduces CO, H, C2H2, C2H4.
Nitrogen Generation and Blanketing
Source: EPT
Nitrogen Blanketing
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ELECTROSTATIC OIL CLEANERS FOR HIGH PATCH WEIGHT, DARK FLUID COLOR
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Electrostatic Oil Cleaners for Particulate Removal and Color Improvement
• Uses principle of Electro Phoresis to remove fine particulate (>0.001 µm) by mass vs. physical size.
• Removes carbon that causes fluid darkening
• When patch weight >4mg/50g of EHC fluid and Fluid Color Improvement is desired
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0
0.005
0.01
0.015
0.02
0.025
0.03
0 2 4 6 8 10 12 14 16 18
Patch Weight (g/50
mL)
Day
Patch Weight ReductionMg/50ml of Fluid
Results – Fluid Color
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E4 ‐ Original Fluid
E4 – After ICB only, no filtration
E4 – After ECR
E4 – After ECR and ICB
Source: EPT
Summary
• Recent high profile EHC losses have insurance companies and Turbine manufacturers paying attention to fluid quality as part of warranty and insurance claims
• Average EHC operators are operating outside of fluid specification on at least one property which creates the risk to power plant owners for uninsured losses and denied warranty claims.– Regulatory considerations?
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Summary
• Many of the issues in EHC fluid maintenance are common from site to site– Testing not complete, maintenance out of date, misapplication of technology
• Technological advances can be leveraged to alleviate these “weak points” in testing and maintenance to make sure all fluid specifications are achieved.
• Operating budgets need to be reset at the minimum safe level that allows for proper maintenance needed and fluid specifications to be achieved.
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Thank you!For Additional Information
Banff National Park, AB, Canada
Peter [email protected]
In Europe contactPatrick Kreutzer
