| 论文简介 |
The boiling flow and heat transfer in the porous media composed of spherical fuel elements exerts significant influences on the reactor’s efficiency and safety. In the present study, an experimental setup is designed and the boiling flow and heat transfer in the porous media composed of regular-distributed spheres are investigated. The test sections mainly consist of a polycarbonate plate for the observation, an aluminum plate with densely distributed hemispheres and a layer of glass spheres. The water flowing in the porous channels is heated by the electrical power through the aluminum plate with hemispheres. Four types of spheres with diameters of 5 mm, 6 mm, 7 mm and 8 mm are involved. In the experimental parameter range, four flow regimes (bubbly flow, bubbly-slug flow, slug flow and slug-annular flow) are observed with considering the effects of heat flux, mass flux and particle diameter. The boiling heat transfer results show that the bigger particles lead to a lower heat transfer coefficient, and result in a higher wall superheat of original nucleation boiling. Finally, a correlation of boiling heat transfer coefficient is proposed based on the measured data. |
(创新港)
