Boiling heat-transfer tube and making method thereof

Abstract

PROBLEM TO BE SOLVED: To provide a boiling heat transfer tube having improved heat transfer performance by improving the wettability of refrigerant liquid to accelerate nuclear boiling, and to provide its manufacturing method. SOLUTION: On the outer peripheral face of a tube 2, fins 3 are formed by continuing spading and bending in such a manner that a spiral or annular cavity portion 31 is formed in the circumferential direction thereof. At the front ends of the fins 3, grooves 35 are formed with protruded portions 33 and recessed portions 34 by using a grooved roll for applying suppressing pressure. The grooves 35 have holes 32 at preset spaces in communication with the outside (refrigerant liquid). COPYRIGHT: (C)2005,JPO&NCIPI

Description

technical field [0001] The present invention relates to an ebullient heat transfer tube and a manufacturing method thereof, and particularly relates to an ebullient heat transfer tube capable of improving the heat transfer performance of a heat transfer tube that heats and boils a refrigerant liquid in a state of being immersed in the refrigerant liquid of a large refrigerator Tubes and methods for their manufacture. Background technique [0002] Larger freezers, such as turbo freezers or spiral freezers, have an evaporator in which boiling heat transfer tubes are used. The boiling heat transfer tube is used to heat the boiling refrigerant liquid, which is immersed in the refrigerant liquid in the evaporator. Efficient heat exchange is very important to the ebullient heat transfer tube, so it has been proposed to form spiral fins (fin fins) on the outer peripheral surface of the tube. For example, fins are formed on the outer surface of the tube, the tops of the fins are p...

AI Technical Summary

Problems solved by technology

Therefore, the upper heat transfer tubes are covered with bubbles formed by boiling caused by the lower heat transfer tubes, so the wettability of the refrigerant liquid deteriorates and the original performance cannot be exhibited.

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