internally enhanced, boiling, water, heat transfer, pressure drop
Flow boiling is a critical process for many thermal conversion processes such as HVAC&R, water heating, power generation, and desalination applications. The goal of this paper is to enhance the in-tube heat transfer for flow boiling of water and thus improve the efficiency of the boiler. This paper presents an experimental investigation of the heat transfer and pressure drop characteristics for water under forced convection and boiling conditions inside both smooth and enhanced tubes. The results in the smooth copper tube are compared with several relevant correlations and the findings have been used as a baseline. The two-phase heat transfer and pressure drop performance of the water flow boiling in the internally enhanced tube is investigated, and the influence of internal surface pattern on the thermal characteristics is discussed. The relations of the heat transfer coefficient with mass flux, heat flux and vapor quality are analyzed, and the findings have been summarized.