Local Pool Boiling Coefficients on the Outside Surface of a Horizontal Tube

摘要

Changes in local pool boiling heat transfer coefficients on the outside surface of a 51 mm dia horizontal tube have been investigated experimentally in water at atmospheric pressure. The local values were determined at every 45 deg from the very bottom to the uppermost of the tube periphery, and a representative value was suggested. The maximum and the minimum local coefficients were observed at the azimuthal angles of 45 and 180 deg, respectively, from the tube bottom. The coefficient at 90 deg can be suggested as the representative of the coefficients. The major mechanisms affecting heat transfer on the surface were liquid agitation and bubble coalescence. Moreover, it is identified that the data can be curve fitted as h{sub}b=C{sub}1+C{sub}2q".