Status of Initial Assessment of Physical and Mechanical Properties of Graphite Grades for NGNP Appkications

Current candidate graphite grades for the core structures of NGNP include grades NBG-17, NBG-18, PCEA and IG-430. Both NBG-17 and NBG-18 are manufactured using pitch coke, and are vibrationally molded. These medium grain products are produced by SGL Carbon SAS (France). Tayo Tanso (Japan) produces IG-430 which is a petroleum coke, isostatically molded, nuclear grade graphite. And PCEA is a medium grain, extruded graphite produced by UCAR Carbon Co. (USA) from petroleum coke. An experimental program has been initiated to develop physical and mechanical properties data for these current candidate graphites. The results will be judged against the requirements for nuclear grade graphites set forth in ASTM standard D 7219-05 "Standard Specification for Isotropic and Near-isotropic Nuclear Graphites". Physical properties data including thermal conductivity and coefficient of thermal expansion, and mechanical properties data including tensile, compressive and flexural strengths will be obtained using the established test methods covered in D-7219 and ASTM C 781-02 "Standard Practice for Testing Graphite and Boronated Graphite Components for High-Temperature Gas-Cooled Nuclear Reactors". Various factors known to effect the properties of graphites will be investigated. These include specimen size, spatial location within a graphite billet, specimen orientation (ag and wg) within a billet, and billet-to-billet variations. The current status of the materials characterization program is reported herein. To date billets of the four graphite grades have been procured, and detailed cut up plans for obtaining the various specimens have been prepared. Particular attention has been given to the traceability of each specimen to its spatial location and orientation within a billet

Status of Initial Assessment of Physical and Mechanical Properties of Graphite Grades for NGNP Appkications

Current candidate graphite grades for the core structures of NGNP include grades NBG-17, NBG-18, PCEA and IG-430. Both NBG-17 and NBG-18 are manufactured using pitch coke, and are vibrationally molded. These medium grain products are produced by SGL Carbon SAS (France). Tayo Tanso (Japan) produces IG-430 which is a petroleum coke, isostatically molded, nuclear grade graphite. And PCEA is a medium grain, extruded graphite produced by UCAR Carbon Co. (USA) from petroleum coke. An experimental program has been initiated to develop physical and mechanical properties data for these current candidate graphites. The results will be judged against the requirements for nuclear grade graphites set forth in ASTM standard D 7219-05 "Standard Specification for Isotropic and Near-isotropic Nuclear Graphites". Physical properties data including thermal conductivity and coefficient of thermal expansion, and mechanical properties data including tensile, compressive and flexural strengths will be obtained using the established test methods covered in D-7219 and ASTM C 781-02 "Standard Practice for Testing Graphite and Boronated Graphite Components for High-Temperature Gas-Cooled Nuclear Reactors". Various factors known to effect the properties of graphites will be investigated. These include specimen size, spatial location within a graphite billet, specimen orientation (ag and wg) within a billet, and billet-to-billet variations. The current status of the materials characterization program is reported herein. To date billets of the four graphite grades have been procured, and detailed cut up plans for obtaining the various specimens have been prepared. Particular attention has been given to the traceability of each specimen to its spatial location and orientation within a billet

Improving the Thermal Performance of Rotary and Linear Air-Cored Permanent Magnet Machines for Direct Drive Wind and Wave Energy Applications

Air-cored machines offer benefits in terms the elimination of magnetic attraction forces between stator and rotor. With no iron in the stator there is not a good thermal conduction path for heat generated by Joule losses in the stator winding. Results from both models and experimental tests are provided in this paper to investigate different methods of cooling air-cored windings, including natural air-cooling, direct liquid cooling and the use of heat pipes

Magnetic and structural analysis of a transverse flux claw pole linear machine

This paper details the design and testing of a novel transverse flux claw pole linear machine suitable for large superconducting generators. The machine utilises a modular claw pole transducer design with a stationary field winding which eliminates the need for cryogenic couplers and electrical brushes for a superconducting machine. The results from this prototype will enable a better understanding of the electromagnetic and mechanical structures before embarking on a more costly super-conducting design. The structure of the prototype supports a field winding and core; four pairs of claw poles with a stroke of 500 mm; three armature windings and core. Tests will be preformed to determine the deflection of the airgap, field core and armature core, the induced voltage in the armature coils, the forces acting on the structure and the flux density variation in the claw poles

Geometry generation for DHV tidal turbine – Basic Python code and implementation in ANSYS-CFX and Rhinoceros

The flow speed which acts on tidal turbines can be increased based on a wide range of approaches. A unique feature of the Davidson Hill Venturi (DHV) turbine is the Venturi shaped structure is produced from individual hydrofoils. This concept includes further parameters, which can be in- dividually changed to find an overall optimum solution. As part of the research project, a general geometry description is provided, which describes the form of the structure by utilising two sym- metrical bell curves. A Phyton script allows the generation of this geometry based on simple inputs. Furthermore, the exemplary integration of this in ANSYS-CFX via SpaceClaim is provided in this dataset. This includes the script file, an example Workbench and a video showing the build-up. An additional Grasshopper code allows to integrate the geometry generation in the CAD software Rhinoceros to allow more complex geometries. The presented data can help to improve the gener- alisation of future optimisation work on this tidal turbine.Gabl, Roman; Burchell, Joseph; Hill, Mark; Ingram, David. (2022). Geometry generation for DHV tidal turbine – Basic Python code and implementation in ANSYS-CFX and Rhinoceros, [dataset]. University of Edinburgh. School of Engineering. FloWave Ocean Energy Research Facility. https://doi.org/10.7488/ds/3455