Optimising Power Generation Maintenance using Thermal and CFD modelling Warwick Ham Boiler Process Engineering Group Leader Steinmüller Africa, Bilfinger Power Systems South Africa
Summary Introduction Failure statistics How to improve availability Using CFD to understand the real causes Record keeping Don t just fix it Change it!
Introduction
Introduction The Coal Fired Power Generation Cycle Economizer Steam Turbine Superheater/Reheater HP - Pipes Generator Steam Generator Feedwater System Condenser Cooling Tower DeNOx - SCR Coal Feeder Firing Systems Coal/Oil/Gas Heat- Recovery System Mill Air Preheater Ash Silo FD - Fan Precipitator FGD De-Ashing De-Ashing ID - Fan FGD - Fan Stack
Failure Statistics The most common types of Failures X Power Station - BTF Mechanism Fatigue Corrosion Fatigue Fly Ash Erosion Falling Object Damage Number of BTFs 18 16 14 12 10 8 6 4 2006 2007 2008 2009 2010 2011 2 2012 0
Failure Statistics Fly Ash Erosion Failure Locations Economiser Reheater Helical Wall Division Wall 18 X Power Station - BTFs per Component 16 14 12 Number of BTFs 10 8 6 4 2 0 Economiser Division wall Screw wallvertical wall Superheater Superheater 1 Superheater 2 Reheater 3 1Reheater 2 2006 2007 2008 2009 2010 2011 2012
Failure Statistics The most common Fly Ash Erosion Causes Operation outside of design envelope Excessive startups/shutdown High ramp rates Excessively high load Operation outside fuel envelope High Ash High Moisture Low CV Erosion High flue gas velocity
Improve Availability How? Design Realistic specifications Operation Procedures Maintenance Adjust maintenance philosophy to actual operating conditions Understand the mechanisms System thinking Detailed CFD investigations
Using CFD Understanding Mill Wear Boiler erosion Pressure Parts Non Pressure Parts Manufacturing Quality
Using CFD Understanding Mill Wear (Video) Excellent agreement between CFD prediction and actual wear patterns
Using CFD Understanding Mill Wear Excellent agreement between CFD prediction and actual wear patterns
Using CFD Understanding Mill Wear Improved design
Using CFD Understanding Boiler erosion Pressure Parts
Using CFD Understanding Boiler Pressure Part Erosion Localisation Erosion Rate
Using CFD Understanding Boiler Non Pressure Part Erosion Localised Rate
Using CFD Understanding Boiler Non Pressure Part Erosion
Using CFD Understanding Maintenance Manufacturing Quality Spherical header
Using CFD Understanding Manufacturing Quality Heat treatment Spherical header Heat treatment procedure
Record keeping the key Design records Basis Fuel Range Operating mode Lifetime Original design assumptions Modifications Maintenance experience
Record keeping the key Operating records Procedures Maintenance records Failure RCA 18 16 14 X Power Station - BTFs Root Cause Number of BTFs 12 10 8 6 4 2 2006 2007 2008 2009 2010 2011 2012 0 Poor workmanship Poor operating Design defect Modification defect Ageing Unknown
Don t just fix it Change it! Assess original design intent against actual conditions Challenge assumptions Assess operating procedures Assess maintenance trends Understand the causes Develop new design basis
Summary Introduction Failure statistics How to improve availability Using CFD to understand the real causes Record keeping Don t just fix it Change it!