| 摘要 |
PURPOSE:To enable to increase the coefficient of overall heat transmission and to decrease pressure loss, by providing a plurality of projections, having uprising surfaces on the upstream side and downwardly inclined to the downstream direction, on the inner wall of a pipe at a specified pitch, slanted against the axis of a pipe, in a heat transfer pipe. CONSTITUTION:Projections 11 having a specified angle of inclinaion to the axis O of a pipe are provided on the inner wall of a pipe body 10 at the specified pitch, in a heat exchanger for a nuclear power plant. The projection 11 has a vertically uprising surface 11a on the upstream side of flow direction of cooling water which flows through the pipe bodyh 10, and an inclined surface 11b which is smoothly inclined downwardly along the flowing direction of cooling water flowing from the upper end of an uprising surface 11a. With such an arrangement, the coefficient of overall heat transmission becomes the maximum when the ratio of pitch Pt of a rib and the height (e) of a rib is around 40 and the angle of inclination theta is around 60 deg.. In such a manner, the coefficient of overall heat transmission can be increased, as well as to decrease the pressure loss in a heat transfer pipe. |
