Heat transfer and pressure drop characteristics of refrigerants evaporating in horizontal spiral-corrugated tubes

The tube-side boiling of Freons in refrigerator forms the major resistance of heat transfer, and so the evaporator requires a large heat transfer area. Recently, it has been found that spiral-corrugated tube (S-tube) has an effect on enhancement of heat transfer for tube-side flow boiling. R-12 was used as working fluid. The test specimen were 3 single-start and 8 multi-start S-tubes, 2 irregular S-tubes and a common bare tube. From these experiments of R-12 tube-side flow boiling, some useful results have been obtained and are described in this paper. The results of this paper, can be used to improve and make optimum design of tube-side flow boiling of Freon evaporators used in refrigerator industry