| 摘要 |
PURPOSE:To prevent the occurrence of the unstable flow of fluid to be heated and to improve heat transfer efficiency, by a method wherein a heat transfer promoting body to increase incurring of a pressure loss is inserted in a preheat area in a heat transfer pipe, and a heat transfer promoter to decrease a pressure loss to a value lower than that of a preheat area is inserted from a nuclear boiling area to an superheat area in a state to be connected to the aforesaid heat transfer pipe. CONSTITUTION:Water entering a heat transfer pipe 1 flows an annular passage, having a narrow flow area, formed between the heat transfer pipe and the outer peripheral surface of a solid round rod 34 situated in a preheat area. The mass velocity in a pipe of water is increased, a pressure loss is increased to promote heat transfer of a heat transfer surface. Water is heat-exchanged with liquid sodium to increase temperature, and flows an annular passage 39 in a preheat area. The water flows a helical flow passage 40 between the heat transfer pipe and a twist tape 36 located in a range of from a nuclear boiling area to a superheat area, a mass velocity in the pipe is decreased, and an increase in a pressure loss is decreased. Thus, the nuclear boiling area having a high heat transfer rate is lengthened, a film boiling area having a low heat transfer rate is shortened, and a heat transfer rate is improved. Further, since a pressure loss in a range of from the nuclear boiling area to the superheat area is decreased and a pressure loss in a preheat area is increased, the generation of an unstable flow in the heat transfer pipe 1 can be prevented. |
