Numerical Modeling of Metal Local Erosion -Corrosion … · elements Operating state and EC ......
Transcript of Numerical Modeling of Metal Local Erosion -Corrosion … · elements Operating state and EC ......
Reporter:Candidate of ScienceCandidate of ScienceShipkov Andrey AnatolievichHead of Calculation-Analysis Department «Geoterm-EM»
IAEAIAEA Technical Workshop, AprilTechnical Workshop, April 2121--23, 23, MoscowMoscow
Numerical Modeling of Metal Local ErosionNumerical Modeling of Metal Local Erosion--Corrosion using Corrosion using RAMEKRAMEK--1 Software Complex1 Software Complex
NPPNPP Metal ErosionMetal Erosion--Corrosion Corrosion
One-(water) and two-phase (wet steam) flows
Water-chemistry
METAL
E/C
Hydro-thermodynamics
Corrosion
Erosion-Corrosion
Exposure time
Metal
Metal
Oxide
Oxide
Methodological Approach to EC Problem Solution at Methodological Approach to EC Problem Solution at NPPsNPPs
Investigation of physical and chemical EC processes and behavior
EC parameters and criteria
Data base
I stage
II stage
III stage
Software information-expertise complex
Complex of application software for NPP personnel support
RESOURCE CAPACITY FACTOR EFFICIENCY FACTOR
SG depositsOperating expenses for diagnostics
Forced outages and accidents
Operating expenses for preventive maintenance
Optimization of preventive maintenance work
Optimization of life extension methods for NPP secondary
circuit elements Optimization of EC diagnostics rules
EC calculation modelCalculation of residual life for NPP secondary circuit
elements
Operating state and EC activity maps of NPPsecondary circuit
EC operating monitoring at NPP
Monitoring of EC operating
characteristicsSample EC test-
module
NPP experience (inspection &
diagnostic methods)
Methods of NPPdamage inquiry
EC sc
ientifi
c res
earch
EC ev
aluati
on
and p
redict
ion
metho
ds
Norm
ative
do
cume
ntatio
n, pra
ctica
l so
lution
s
Tech
nical
& ec
onom
ical
result
s
Main Factors and Parameters of Main Factors and Parameters of NPPNPP Metal ErosionMetal Erosion--CorrosionCorrosion
�� Chemical compositionChemical composition of steelof steel % (% (Cr, Mo, CuCr, Mo, Cu).).�� Phase statePhase state of working environmentof working environment ((waterwater, ,
wet steamwet steam →→ moisture degreemoisture degree, %)., %).�� WaterWater--chemistry modechemistry mode ((рНрН local valueslocal values, , amineamine, ,
ОО22, , gas and impurities gas and impurities interphaseinterphase distribution factorsdistribution factors).).�� ThermoThermo--dynamics and physical properties of working environment dynamics and physical properties of working environment
((t, Pt, P, , ρρ,,, , ρρ,,,,,, νν,,, , νν,,,,, , σσ ……).).�� Average flow rateAverage flow rate..�� Exposure time Exposure time ((operationoperation).).
�� Channel geometryChannel geometry ((teetee, , bendbend, , narrowingnarrowing etc.etc.).).
�� Characteristics of channel with complex geometry Characteristics of channel with complex geometry ((flowing part profile).flowing part profile).�� Peculiarities of flow hydroPeculiarities of flow hydro--dynamicsdynamics::
-- local gradients of flow velocity local gradients of flow velocity dUxdUx((convection mechanism of mass transferconvection mechanism of mass transfer););
-- locallocal energy gradient of turbulent pulsations energy gradient of turbulent pulsations dKdK((vortex mechanism of mass transfer)vortex mechanism of mass transfer)..
++
GECGEC
LEC
LEC
dr
dr
Calculation Investigations of Carbon Steel Calculation Investigations of Carbon Steel ((StSt 20) 20) ErosionErosion--Corrosion Corrosion with with RAMEKRAMEK--2 Model2 Model
General Scheme of Local Area Identification and Wear (Thinning) General Scheme of Local Area Identification and Wear (Thinning) Activity Activity for Pipelines and Components Elements and Units for Pipelines and Components Elements and Units
of of NPPNPP CondensateCondensate--FeedwaterFeedwater CircuitCircuit
Pipeline units
Standard elements
GEC LEC
Cav yes CavE
no
no
yes
Preswitchedelements
pH values range of H2O liquid phase for different power units: I – NPPs with VVER-1000 (9.0+/- 0.2)II-French NPPs (9.2+/- 0.1)III-thermal electric plants, hydrazine mode (7.7+/- 0.2)IV-thermal electric plants, oxygen-ammonia mode (8.0+/- 0.5)
ammonia hydrazine morpholine ODAammonia 36 mkg/kg
Hydrazine 5 mkg/kg
Morpholine50 mkg/kgODA 30 mkg/kg
Calculation Calculation TopogramTopogram for Metal Erosionfor Metal Erosion--Corrosion Activity Corrosion Activity ((StSt20)20)of of 22RL74SO4RL74SO4 Regulator Bypass Inlet Bending and Connecting PipeRegulator Bypass Inlet Bending and Connecting Pipe by by RAMEKRAMEK--11
F low dir ection
Weld3 hours
bending
Connecting pipe
0 hours9 hours
6 hours
3 hours
mm/year
S, mm/year
Location of ErosionLocation of Erosion--Corrosion Damage at LP Heater Vessel Corrosion Damage at LP Heater Vessel №№6565and Numerical Modeling of Steam Flow Rate Vector Field and Numerical Modeling of Steam Flow Rate Vector Field at at
Smolensk Smolensk NPPNPP LP Heater Vessel InletLP Heater Vessel Inlet
W e t s t e a m
f l ow
Photo of damage atLP heater vessel N 65
Physical Picture of Deposit Area Generation and Liquid Film Physical Picture of Deposit Area Generation and Liquid Film TurbulizationTurbulization at the at the LPHLPH N65 Vessel Surface N65 Vessel Surface
of Smolensk of Smolensk RBMKRBMK--1000 Unit1000 UnitActive LEC area
Stagnation area
Max LEC area
Fusion areas of deposit and liquid film turbulization flowsLines of flow division
Conditions of active LEC implementation•Moisture degree >1.5-2.0%•Wet steam flows fusion and braking•Low velocity of wet steam flows W<=2,0-3,0 m/s (i.e. lack of breakaway and droplet moisture carry-over from liquid film surface)
Application of ErosionApplication of Erosion--Corrosion Calculation models Corrosion Calculation models ((RAMEKRAMEK) to Solve the Complex Program Tasks) to Solve the Complex Program Tasks
RAMEK
Identification of local areas with EC maximum activity in pipelines elements
Evaluation of metal EC activity based on modeling of physical-chemical processes considering EC
mechanisms
Metal EC prediction and evaluation of pipeline residual life
Optimization of preventive maintenance work
Implementation of erosion-corrosion monitoring at NPP
Review of guidelines, standard programs and instructions on inspection and management of NPP pipelines resource
Generation of controlled data base and maps of pipeline EC damageability
Optimization of inspection & diagnostics measures
for NPP personnel and specialized organizations
Identification of metal EC sensitivity of specific pipeline element to changing
different parameters and characteristics