An experimental investigation of the influence of threaded surface on the boiling heat transfer coefficients in vertical narrow channels

摘要

One efficient method of cooling electronics is to use a closed-loop two-phase thermosyphon system. The setup tested here utilizes three small evaporators connected in parallel, each made from a small block of copper in which five vertical channels with diameter 1.5mm and length 15 mm were drilled. The article presents the experimental results in terms of heat transfer coefficients of smooth surfaces as well as for threaded surfaces. Tests were done at different heat fluxes while maintaining constant system pressure. Tests were performed with heat loads of 30-450 W dissipated through the system. Two different refrigerants, R134a and R600a, were tested. The experimental two-phase flow heat transfer coefficients were compared to correlations from the literature.