3D Conjugate Heat Transfer Analysis of the Next Generation ...mdx2.plm.automation.siemens.com/sites/default/files/Presentation/3... · Generation Inner Reflector Plug for the Spallation

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

STAR Global Conference 2013

Orlando, Florida, USA

March 18-20, 2013

2 Managed by UT-Battelle for the U.S. Department of Energy STAR Global Conference 2013

The Spallation Neutron Source at ORNL

LINAC

Accelerate the beam to 1 GeV

Accumulator Ring

Compress 1 msec long

pulse to 700 nsec

Target building & neutron

instruments Proton beam pulses to Target at 60 Hz

Central Laboratory

& Office Complex

Center for Nanophase Material Science


SNS Instruments Cover a Wide Range of Science

18 neutron beam lines

some accommodate more that 1 instrument


Proton Beam Liquid Mercury Target Module

Reflector Plugs

SNS Target Systems Core Region


SNS Target Systems Core Region

Inner Reflector Plug

Outer Reflector Plug

Core Vessel

Proton Beam Window

Neutron Beam Lines Target

Moderators (4)

Proton

Beam


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


2nd

Generation Inner Reflector Plug (IRP)

Proton

Beam Target

Middle Reflector Plug

(MRP)

Lower IRP SS, Be, Al, and Cd

31.75” OD X 73” tall, 7000 lbs.

Intermediate IRP Stainless Steel

31.75” OD X 22” tall, 4095 lbs.

Be

Be

Existing IRP


2nd

Generation MRP Design

Outlet Inlet

80 gpm

40 C

Aluminum Can

2 SS inserts

Inle

t s

ide

Ou

tle

t s

ide

Proton Beam

0.25 inch

0.25 inch

Hole diameters in the inlet side is 0.5 inch

Hole diameters in the outlet side is 0.375 inch

Heavy Water

Water Plenum


2nd

Generation IRP Design

Beryllium Aluminum

Light Water

Pre-Moderators

Heavy Water

40 gpm

40 C

40 gpm

40 C

Outlet

15 gpm each

40 C

15.85 gpm

40 C

15.85 gpm

40 C


Volumetric Heat Generation (W/m3) in Aluminum

at 2 MW Beam Power

IRP MRP


Water/AL interface

Temperature Contours at Water/SS, Water/AL and

Water tubes/SS interfaces

Water/SS interface

SS/Water tubes interface

SS Insert1

SS Insert2


SNS Mercury Target Module

Mercury vessel surrounded by a water-cooled shroud

Bulk mercury flow

Water-cooled Shroud

Mercury Target Vessel

Proton Beam

quasi-stagnation region at the

center of the window

Re = 0.7×106

12 L/s


Conjugate Heat Transfer of SNS Liquid Mercury

(1.54 MW Beam Power)

Deposited Power In SS: 63.8 kW

Deposited Power in HG: 777.46 kW

Constant Volume Heating Process Leads

to Large Pressure Pulse in Liquid Mercury


Conjugate Heat Transfer of SNS Liquid

Mercury

• K- SST Mentor turbulence model

• Turbulent Prantdl number


Cavitation Damage Erosion of the Target Module

Target # 8 is running at about 1 MW Beam Power

Specimen diameter: 60 mm

Original thickness: 3 mm

Off-center, bulk Hg surface Center, bulk Hg surface


Textured SNS window: 24 L/s

Conical pits

Stagnation Zone

Vertical V Grooves

Gas Injection: 500 sccm per port

Vertical V Grooves

Horizontal V Grooves Horizontal V Grooves Horizontal V Grooves Horizontal V Grooves

Horizontal V Grooves Horizontal V Grooves

Sweeping Mercury Flow Sweeping Mercury Flow

Close up view


Experiments in liquid Mercury:

Video of Textured Gas Wall at the window (24L/s)

Conical Pits

Vertical

Grooves

Vertical

Grooves

He gas injection at 500 sccm each

Horizontal

Feeder

Grooves


Time Averaged Helium VF Contours


Animation of Gas Volume Fraction contours (24 L/s)


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.

Comments:

• 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


Thanks for your attention

Documents

3D Conjugate Heat Transfer Analysis of the Next Generation ...mdx2.plm.automation.siemens.com/sites/default/files/Presentation/3... · Generation Inner Reflector Plug for the Spallation