Fissuration des culasses des moteurs diesel de secours du parc 900 - - PowerPoint PPT Presentation

Fissuration des culasses des moteurs diesel de secours du parc 900 MWe Cylinder heads cracking of 900 MWe reactors back- up diesel generators

Salome-Meca 2018 users day – March 20th – EDF Lab Paris-Saclay Robin Degeilh, Dominique Geoffroy, Samuel Géniaut, David Haboussa (R&D/ERMES), François Curtit (R&D/MMC) Client : Fréderic Gaudeaux (DPN/UNIE/GMAP)

| 2 Cylinder heads cracking of 900 MWe reactors back-up diesel generators

INTRODUCTION

CONTEXT

30 x start / shut down per year

| 3 Cylinder heads cracking of 900 MWe reactors back-up diesel generators

INTRODUCTION

CONTEXT

| 4 Cylinder heads cracking of 900 MWe reactors back-up diesel generators

INTRODUCTION

CONTEXT

Valves bridge cracking Crack Water cooling Combustion chamber

| 5 Cylinder heads cracking of 900 MWe reactors back-up diesel generators

INTRODUCTION

CONTEXT

Can bridge cracks propagate up to motor failure ? UNIE: Need to define (and justify to ASN) the maintenance program

| 6 Cylinder heads cracking of 900 MWe reactors back-up diesel generators

Thermal simulation of a start / shut down motor cycle Determination of crack growth rate

SUMMARY

Conclusion Mechanical simulation of a start / shut down motor cycle Realisation of the CAD model and mesh

1 6 5 4 3 2

Material Thermo-mechanical properties

| 7 Cylinder heads cracking of 900 MWe reactors back-up diesel generators

Thermal simulation of a start / shut down motor cycle Determination of crack growth rate

SUMMARY

Conclusion Mechanical simulation of a start / shut down motor cycle Realisation of the CAD model and mesh

1 6 5 4 3 2

Material Thermo-mechanical properties

| 8 Cylinder heads cracking of 900 MWe reactors back-up diesel generators

Tests at 20, 220 and 420°C

Monotonous tensile test Cyclic compression/tensil test Fatigue propagation test

IDENTIFICATION OF THERMO-MECHANICAL PROPERTIES

EXPERIMENTAL CHARACTERIZATION

Cast iron GJL300 from rejected cylinder heads Elastic-plastic behaviour

| 9 Cylinder heads cracking of 900 MWe reactors back-up diesel generators

Tests at 20, 220 and 420°C

Monotonous tensile test Cyclic compression/tensil test Fatigue propagation test

IDENTIFICATION OF THERMO-MECHANICAL PROPERTIES

EXPERIMENTAL CHARACTERIZATION

Tension/compression dissymmetry Growing symmetrical strain controlled test

Applied strain

| 10 Cylinder heads cracking of 900 MWe reactors back-up diesel generators

Tests at 20, 220 and 420°C

Monotonous tensile test Cyclic compression/tensil test Fatigue propagation test

IDENTIFICATION OF THERMO-MECHANICAL PROPERTIES

EXPERIMENTAL CHARACTERIZATION

Température Cmoyen mmoyen 20°C 1,77E-12 6,65 220°C 3,98E-12 6,55 420°C 1,83E-11 6,50

| 11 Cylinder heads cracking of 900 MWe reactors back-up diesel generators

IDENTIFICATION OF THERMO-MECHANICAL PROPERTIES

CONSTITUTIVE MODEL DEVELOPMENT

code_aster Identification at 20, 220 and 420°C Implementation MFront Development non-linear kinematic hardening function of sign of trace(σ)

| 12 Cylinder heads cracking of 900 MWe reactors back-up diesel generators

Thermal simulation of a start / shut down motor cycle Determination of crack growth rate

SUMMARY

Conclusion Mechanical simulation of a start / shut down motor cycle Realisation of the CAD model and mesh

1 6 5 4 3 2

Material Thermo-mechanical properties

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NUMERICAL MODEL

3D CAD

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NUMERICAL MODEL

3D SANE MESH

640 000 nodes Element size ~2mm

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NUMERICAL MODEL

3D CRACKED MESHES

One crack per bridge  3 meshes 28mm 20mm Maximal measured length according to UNIE Zcracks

| 16 Cylinder heads cracking of 900 MWe reactors back-up diesel generators

Thermal simulation of a start / shut down motor cycle Determination of crack growth rate

SUMMARY

Conclusion Mechanical simulation of a start / shut down motor cycle Realisation of the CAD model and mesh

1 6 5 4 3 2

Material Thermo-mechanical properties

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T=20°C Start Temperature stabilisation Shut down

THERMAL SIMULATION OF A MOTOR CYCLE

BOUNDARY CONDITIONS - START

Exchange condition Exchange condition Exchange condition Exchange condition = h(r)

50 100 150 200 250 300 350 400 50 100 150 200 250 300

Température (°C) Temps (s)

PAA PAE1 PAE2 PEE

r

| 18 Cylinder heads cracking of 900 MWe reactors back-up diesel generators

T=20°C Start Temperature stabilisation Shut down

THERMAL SIMULATION OF A MOTOR CYCLE

BOUNDARY CONDITIONS - STABILISATION

Exchange condition Exchange condition Exchange condition Exchange condition = h(r) r

50 100 150 200 250 300 350 400 450 500 20 40 60 80 100 120 140 Temperature (°C) Radius (mm) Mesure Calcul

| 19 Cylinder heads cracking of 900 MWe reactors back-up diesel generators

50 100 150 200 250 300 350 400 300 2 300 4 300 6 300 8 300 10 300 12 300 14 300 16 300

Temperature (°C) Time (s)

PAA PAE1 PAE2 PEE

T=20°C Start Temperature stabilisation Shut down

THERMAL SIMULATION OF A MOTOR CYCLE

BOUNDARY CONDITIONS – SHUT DOWN

Exchange condition(water flow /50)

| 20 Cylinder heads cracking of 900 MWe reactors back-up diesel generators

THERMAL SIMULATION OF A MOTOR CYCLE

RESULT

| 21 Cylinder heads cracking of 900 MWe reactors back-up diesel generators

Thermal simulation of a start / shut down motor cycle Determination of crack growth rate

SUMMARY

Conclusion Mechanical simulation of a start / shut down motor cycle Realisation of the CAD model and mesh

1 6 5 4 3 2

Material Thermo-mechanical properties

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MECHANICAL SIMULATION OF A MOTOR CYCLE

BOUNDARY CONDITIONS

normal displacement=0

r

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MECHANICAL SIMULATION OF A MOTOR CYCLE

RESULT ON SANE MESH

End of start End of shut down

| 24 Cylinder heads cracking of 900 MWe reactors back-up diesel generators

MECHANICAL SIMULATION OF A MOTOR CYCLE

RESULT ON SANE MESH

End of start End of shut down

End of start End of shut down

Linear mesh Quadratic mesh Depth (mm)

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MECHANICAL SIMULATION OF A MOTOR CYCLE

RESULT ON CRACKED MESH

| 26 Cylinder heads cracking of 900 MWe reactors back-up diesel generators

Thermal simulation of a start / shut down motor cycle Determination of crack growth rate

SUMMARY

Conclusion Mechanical simulation of a start / shut down motor cycle Realisation of the CAD model and mesh

1 6 5 4 3 2

Material Thermo-mechanical properties

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DETERMINATION OF CRACK GROWTH RATE

RESULTS IN ΔK

Post-treatment with POST_K1_K2_K3 (elastic) Cracking rate Paris law Curvilinear abscise (mm) Bridge C Bridge A Bridge D

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DETERMINATION OF CRACK GROWTH RATE

RESULTS IN CRACK GROWTH

Bridge A Bridge C Bridge D 1500 start / shut down

Margin=7,10mm Margin=7,01mm Margin=7,75mm

| 29 Cylinder heads cracking of 900 MWe reactors back-up diesel generators

Thermal simulation of a start / shut down motor cycle Determination of crack growth rate

SUMMARY

Conclusion Mechanical simulation of a start / shut down motor cycle Realisation of the CAD model and mesh

1 6 5 4 3 2

Material Thermo-mechanical properties

| 30 Cylinder heads cracking of 900 MWe reactors back-up diesel generators

CONCLUSION

Note EDF R&D 6125-1716-2017-00547-FR « Projet MODERN - Justification de la tenue des culasses des moteurs diesels des tranches 900 MWe (LP 3.6) »

Can bridge cracks propagate up to motor failure ? Bridge cracks cannot propagate up to motor break down over 1500 start / shut down

• Experimental mechanical characterisation
• New cyclic inelastic behaviour model in MFront
• 3D complex shape CAD from plans
• Thermo-mechanical study in code_aster

Questions ?