Falling-Film Evaporation on Tube Bundle with Plain and Enhanced Tubes—Part I: Experimental Results

摘要: Abstract The complexities of two-phase flow and falling-film evaporation on a tube bundle present important challenges in the design heat exchangers understanding physical phenomena taking place. development structured surfaces to enhance nucleate boiling transfer and, thus, reduce size evaporators adds another level complexity, requiring characterization effect enhanced occurring evaporator. In this article, measurements single row three-row were performed obtain local coefficients. Four types tubes tested: plain tube, an condensing (Gewa-C+LW, Wieland Werke, Ulm, Germany) two (Turbo-EDE2, Wolverine, Hunstville, Alabama, USA; Gewa-B4, Germany). Two refrigerants, R134a R236fa, tested at saturation temperature 5°C, liquid film Reynolds numbers...