| 摘要 |
A heat transfer surface for effecting boiling of a high pressure refrigerant in contact with the surface. The surface includes a plurality of spaced apart fins (12) which extend from the side in contact with the boiling fluid. Each of the fins (12) has a base portion joined to the base of the surface and a tip portion (14). The tip portions (14) are bent over towards the next adjacent one of the fins (12) to define a subsurface channel between adjacent fins (12). The sub-surface channel has alternating closed sections (16) where a length of the tip portion (14) is bent over by an additional amount so that the length of the tip portion (14) contacts an adjacent fin (12), and, open sections (18) wherein the bent over the tip portion (14) is spaced from the adjacent fin (12). Each of the open sections (18) has a cross sectional area of from 0.0034 mm <2>to 0.0068 mm <2>(.000220 square inches to .000440 square inches) such that the open sections (18) define alternating re-entrant openings of a size to promote optimum boiling of a high pressure refrigerant. The total open area of the open sections (18) is from 14% to 28% of the total surface area. <IMAGE> |
