3D Conjugate Heat Transfer Analysis of the Next Generation Inner - PowerPoint PPT Presentation

3D Conjugate Heat Transfer Analysis of the Next Generation Inner Reflector Plug for the Spallation Neutron Source Ashraf Abdou Oak Ridge National Laboratory , Oak Ridge TN, USA March 18-20, 2013 STAR Global Conference 2013 Orlando, Florida, USA

The Spallation Neutron Source at ORNL LIN LINAC Accumula Accumulator tor Ring Ring Accelerate the beam to 1 GeV Central Laboratory Compress 1 msec long & Office Complex pulse to 700 nsec Target building & neutron instruments Proton beam pulses to Target at 60 Hz Center for Nanophase Material Science 2 Managed by UT-Battelle STAR Global Conference 2013 for the U.S. Department of Energy

SNS Instruments Cover a Wide Range of Science 18 neutron beam lines some accommodate more that 1 instrument 3 Managed by UT-Battelle STAR Global Conference 2013 for the U.S. Department of Energy

SNS Target Systems Core Region Proton Beam Liquid Mercury Target Module Reflector Plugs 4 Managed by UT-Battelle STAR Global Conference 2013 for the U.S. Department of Energy

SNS Target Systems Core Region Inner Reflector Plug Moderators (4) Outer Reflector Plug Core Vessel Proton Beam Window Proton Beam Neutron Beam Lines Target 5 Managed by UT-Battelle STAR Global Conference 2013 for the U.S. Department of Energy

CFD Simulations of SNS Systems • SNS Systems are built in PRO-E Creo parametrics • Neutronics Analysis – Codes: MCNPX and other codes – Volumetric power deposition in Liquids and solids • Thermal-Hydraulic Analysis – Codes: STAR-CCM+V7 , ANSYS-CFX, Fluent V14.5 and ICEM-CFD – Grids: conformal Hexahedral and Polyhedral – Conjugate Heat Transfer Analysis – Two-Phase Flow for Gas layers and gas bubbles – Fluids: Liquid mercury, heavy and light water, supercritical hydrogen and gases • Stress Analysis – Codes: ABAQUS and ANSYS 6 Managed by UT-Battelle STAR Global Conference 2013 for the U.S. Department of Energy

2 nd Generation Inner Reflector Plug (IRP) Intermediate IRP Stainless Steel 31.75 ” OD X 22” tall, 4095 lbs. Middle Reflector Plug ( MRP) Be Proton oton Tar arget get Beam Beam Lower IRP Be SS, Be, Al, and Cd 31.75 ” OD X 73” tall, 7000 lbs. Existing IRP 7 Managed by UT-Battelle STAR Global Conference 2013 for the U.S. Department of Energy

2 nd Generation MRP Design 2 SS inserts 0.25 inch Inlet Outlet 80 gpm 40  C Heavy Hea vy Water ter 0.25 inch Outlet side Inlet side Proton Beam Hole diameters in the inlet side is 0.5 inch Hole diameters in the outlet side is 0.375 inch Water Plenum Aluminum Can 8 Managed by UT-Battelle STAR Global Conference 2013 for the U.S. Department of Energy

2 nd Generation IRP Design 40 gpm 40  C Light W Light Water ter 15 gpm each 40  C Outlet Pr Pre-Moderators 15.85 gpm 40  C 40 gpm 40  C Hea Heavy vy Water ter Beryll Ber yllium ium Al Aluminu uminum 9 Managed by UT-Battelle 15.85 gpm STAR Global Conference 2013 for the U.S. Department of Energy 40  C

Volume olumetri tric c Hea Heat t Gene Generati tion on ( (W/m W/m 3 ) ) in A in Aluminum luminum at 2 t 2 MW Be MW Beam am P Power er IRP 10 Managed by UT-Battelle MRP STAR Global Conference 2013 for the U.S. Department of Energy

Temperature Contours at Water/SS, Water/AL and Water tubes/SS interfaces SS SS/W /Water t ter tube ubes interf s interface ace Water ter/A /AL L inter interface ace SS Insert1 SS Insert2 11 Managed by UT-Battelle Water/SS interface STAR Global Conference 2013 for the U.S. Department of Energy

SNS Mercury Target Module Mercury vessel surrounded by a water-cooled shroud Mercury Target Vessel Water-cooled Shroud 12 L/s Proton Beam quasi-stagnation region at the center of the window Re = 0.7 × 10 6 Bulk mercury flow 12 Managed by UT-Battelle STAR Global Conference 2013 for the U.S. Department of Energy

Conjugate Heat Transfer of SNS Liquid Mercury (1.54 MW Beam Power) Constant Volume Heating Process Leads to Large Pressure Pulse in Liquid Mercury Deposited Power In SS: 63.8 kW 13 Managed by UT-Battelle STAR Global Conference 2013 for the U.S. Department of Energy Deposited Power in HG: 777.46 kW

Conjugate Heat Transfer of SNS Liquid Mercury K-  SST Mentor turbulence model • • Turbulent Prantdl number 14 Managed by UT-Battelle STAR Global Conference 2013 for the U.S. Department of Energy

Ca Cavit vitation tion Dama Damage ge Er Erosion osion of of the T the Tar arget get Module Module Tar arget # get # 8 is 8 is running unning at t about 1 M bout 1 MW W Beam Beam Power er Specimen diameter: 60 mm Original thickness: 3 mm 15 Managed by UT-Battelle Off-center, bulk Hg surface STAR Global Conference 2013 Center, bulk Hg surface for the U.S. Department of Energy

Textured SNS window: 24 L/s Close up view Horizontal V Grooves Horizontal V Grooves Vertical V Grooves Vertical V Grooves Conical pits Stagnation Zone Sweeping Mercury Flow Sweeping Mercury Flow Horizontal V Grooves Horizontal V Grooves Horizontal V Grooves Horizontal V Grooves 16 Managed by UT-Battelle STAR Global Conference 2013 for the U.S. Department of Energy Gas Injection: 500 sccm per port

Experiments in liquid Mercury: Video of Textured Gas Wall at the window (24L/s) Conical Pits Vertical Vertical Grooves Grooves Horizontal Feeder Grooves He gas injection at 500 sccm each 17 Managed by UT-Battelle STAR Global Conference 2013 for the U.S. Department of Energy

Time Averaged Helium VF Contours 18 Managed by UT-Battelle STAR Global Conference 2013 for the U.S. Department of Energy

Animation of Gas Volume Fraction contours (24 L/s) 19 Managed by UT-Battelle STAR Global Conference 2013 for the U.S. Department of Energy

Summar Summary • STAR-CCM+ is being used at SNS for : – conjugate heat transfer with water in complex geometries – conjugate heat transfer with liquid metal in separated flows – Two-Phase flow for developing gas wall layer over textured wall • The simulations provide guidance for the experiments, and may be used as a diagnostic tool for probing inside the opaque mercury. CFD is thus demonstrated to be a promising method for optimization of a gas wall to mitigate cavitation erosion of the SNS target. Comment Comme nts: s: Communication between PRO-E Creo and STAR-CCM+ CAD thru 3D CAD Exchange to • prepare the models for conformal polyhedral grid • Interface Imprinter in STAR-CCM+ CAD with importing Para solid and IGES files Parametric studies: Writing the solution settings, BCs and etc. into a file then read this file for • different cases for easy setup for the models • Comparison between mapped interfaces with direct and indirect mapping for both conformal and non- conformal grids 20 Managed by UT-Battelle STAR Global Conference 2013 for the U.S. Department of Energy

Thanks for your attention 21 Managed by UT-Battelle STAR Global Conference 2013 for the U.S. Department of Energy