Microporous Coatings for Enhance Heat Transfer and Impulse Tube Repair. Timothy J. Eden, Ph.D.

Transcription

1 Microporous Coatings for Enhance Heat Transfer and Impulse Tube Repair Timothy J. Eden, Ph.D. North American Cold Spray Conference Edmonton, Alberta, Canada Nov 30-Dec 1,2016 Mechanical and Nuclear Engineering

2 Collaborators Initial Porous Coating Development and Testing Timothy J. Eden, Ph.D. 1,2 Albert Segall, Ph.D. 2 Fan-Bill Cheung 3 1 Applied Research Laboratory 2 Engineering Science and Mechanics 3 Mechanical Engineering Porous Coating for Nuclear Reactors Project Development, Management and Testing Dr. Jiří Žďárek Vice-president for Business Development Division of Integrity and Technical Engineering ÚJV Řež, a. s. Tube Repair Aaron Nardi United Technologies Research Center Victor Champagne Army Research Laboratory Modeling Jeremy Schreiber, Ph.D 1,2 Victor Champagne Army Research Laboratory

3 Introduction Established in 1945 by the Navy Technology Areas Largest Interdisciplinary Research Unit at Penn State 1148 faculty/engineers, staff, students Designated an University Affiliated Research Center by DoD in 1996 Navy Designated University Affiliated Research Center (UARC) Comprehensive technical expertise in Undersea Weapons, Vehicles, UUV s Hydrodynamics and Structures Acoustics & Noise Reduction Communication and Information Power and Energy Materials and Manufacturing Trusted Agent Quick response capability Omnibus contract

4 Porous Coating Development Objective Create tailored micro-porous coatings for reactor head to enhance downward facing boiling heattransfer during emergency flooding: Eliminate boiling crisis caused by the vapor layer Increase critical heat flux (CHF) Contain or slow down release of molten Corium (In Vessel Retention or IVR) Solution Cold spray coating Interconnected Porosity Good Adhesion to steel Applied to existing reactors

5 Cold Spray Coating Development Composite stainless steel coatings Varied % of SS Optimized porosity and adhesion Water absorption tests Sub-scale flow and heat transfer evaluation Porous Coating - ~3% porosity Water Absorption Testing Test Section

6 Unique Sub-scale Boundary Layer Boiling (SBLB) test facility used to assess Critical Heat FluxBL) test facility used to assess critical heat flux Cold Spray

7 Coating Process Apply coating to a 300 mm (12 in) steel hemisphere Nitrogen as the main process gas Develop robot programing to deposit uniform coating Cold Spray

8 Enhanced Heat Transfer Heated sphere to 365º C Immersed in 100º C Water Transient Temperatures During Quenching of Uncoated and Coated Hemispheres 8

9 Boiling Experiments Bare Vessel t=0 sec t=4 sec t=13 sec Coated Vessel 9

10 Large Scale Test Section Designed and fabricated by UJV Simulate full-scale geometry and operation Evaluation of enhanced surfaces Demonstrate deposition process Evaluate coating performance Porous Coating Development

11 Impulse Tube Repair Material Czech Standard CSN Tensile Strength: MPA Yield Stress: 265 MPA Elongation 23% Hardness Base Material: VHN Heat Affected Zone: VHN Weld: VHN Leak Tube cracked during operation Stream Impulse Tube Crack in Stream Impulse Tube 11

12 Impulse Tube Repair Repair Cold Spray using the VRC Gen III VRC performed the repair NiCr-Cr 3 C 2 He Testing Pressure Testing 18.6 MPa (2740 psi), 25ºC 18.6 MPa, 325ºC (617ºF) Hold Time - 1 hour Impulse Tube with Cold Spray Repair Test Step Test fixture for Impulse Tube 12

13 Impulse Tube Repair Tube Evaluation Magnetic Memory of Materials (MMM) Performed on length of the tube At several angles around the perimeter Shows stress concentrations Measures the stress concentrations in the tube due to the welds No increased stress concentration from the Cold Spray Repair was measured Impulse Tube Mounted for MMM Evaluation Results of the MMM Evaluation 13

14 Impulse Tube Repair Tube Repair Evaluation Applied coating on 13 mm (0.5 in) OD, 7mm (0.26 in) split (internal crack316 SS stainless steel tube Coating Deposition mm (0.05 in) coating (Nickel + Chrome Carbide, Ni-CRC) Nozzles Standard Length Nozzle (200 mm) Mini-ID Nozzle Main Process Gas He N2 Pulled tube in tension Determined fracture toughness for a tube with an internal circumferential crack 14

15 Global Nuclear Power Safety (GNPS) Center Mission: Director Prof. Fan-Bill Chueng Advance the base technology in nuclear power (NP) safety and develop marketable research tools and products that are useful for: Promoting the safe operation and performance of existing nuclear power plants Developing inherently safe, future advanced high-power reactors Educating, training and developing professional engineers, practitioners, designers, researchers, and students working in NP safety University experts who specialize in nuclear safety, including nuclear fuel and materials, advanced instrumentation and control, innovative cooling enhancement, experimental support, system code development and education and training. Innovative Cooling Enhancement (ICE) Profs Albert Segall and Tim Eden Develop innovative cooling technology for the nuclear industry

16 Bonding Model Development Strain Energy Bonding Model Army Research Laboratory Modeling Effort Develop a comprehensive model of the bonding mechanism in the cold spray process Implement the Preston-Tonks-Wallace high strain rate plasticity model Compare results with experiments Develop a strain based bonding/debonding criteria Transition from single particle to multiparticle impact Compare results with bulk adhesion data

17 Johnson-Cook Constitutive Material Model Empirically based material model that relies on five material parameters to predict flow stress. Without strain-rate corrections, only valid for strain-rates from quasi-static to 10 4 /sec. σ y = A + Bε p n 1 + Clnεሶ p 1 T H m A = quasi-static yield strength B = power law pre-exponential factor C = strain rate pre-exponential factor n = strain hardening exponent m = thermal softening exponent Flow stress prediction for AISI 4340 steel using Johnson- Cook Equation at various strain-rates [J. Schreiber].

18 Ƹ Preston-Tonks-Wallace Material Model Physics based materials model that is capable of predicting yield stresses at strainrates ranging from 10-3 to /sec Relies on three dimensionless variables that are based on: Flow stress Temperature Strain-rate τ Ƹ = τƹ s + 1 p s 0 τƹ y ln 1 1 exp p τƹ s τƹ y s 0 Ƹ τ y exp ቆs 0 τƹ y ) exp τ s - normalized work hardening stress (how the model accounts for strain hardening) s 0 - saturation shear stress at 0K τ y - Normalized yield stress (at low strain rates), saturation stress (at high strain rates) p hardening parameter θ hardening constant ψ scaled equivalent plastic strain rate value Finite element subroutine prediction agrees with experimental data pθψ p τƹ s τƹ y 1 s 0 τƹ y D.L. Preston, D.L. Tonks, D.C. Wallace, Model of plastic deformation for extreme loading conditions, J. Appl. Phys. 93 (2003) 211. doi: /

19 WPI is calculating material properties using thermodynamic databases and experiments Single Particle Impact Modeling

20 Additive-Subtractive Cold Spray Based Manufacturing Station ONR Defense University Research Instrumentation Program DURIP VRC Gen III Cold Spray System Max Gas Pressure Max Gas Temp at gun Max Heater Powder Deposition rate Data logging and storage HAAS VF-3 CNC Mill Rotary Table Pallet Changer Dimensional probe and tool setter Fully Integrated ABB Robot SolidWorks SolidCam 6.9 bar 750 C 45 kw 7 kg/hr

21 Additive-Subtractive Cold Spray Based Manufacturing Station