High heat flux testing of a helium-cooled tungsten tube with porous foam

摘要

Utramet, Inc. fabricated one-piece heat exchanger tubes of chemical vapor deposited (CVD) tungsten (W), each with an internal porous mesh fused along either 51 or 38 mm of the axial length of a tube 15 mm in outer diameter. The open porous mesh has a structure of joined ligaments that combines relatively low resistance to flow and a large area for heat transfer. In tests at the Electron Beam Test Stand (EBTS) at Sandia National Laboratories, the maximum absorbed heat load was 22.4 MW/m~2 with helium at 4 MPa, flowing at 27 g/s and with inlet and outlet temperatures of 40 and 91 ℃ and a pressure drop of ～0.07 MPa. The preparation and testing of the samples was funded through a Phase I grant by the US Department of Energy's Small Business Innovation Research Program. The paper reports the surface temperature distribution indicated by an infrared camera, test conditions, a post-test examination in a scanning electron microscope and other details.