On the Presentation of Performance Data for Enhanced Tubes Used in Shell-and-Tube Heat Exchangers

As the efforts to produce more efficient heat transfer equipment continue, an increasing number of augmented surfaces are being produced commercially. Consequently, the designer faces an almost overwhelming task in comparing and evaluating the performance of various surfaces because of the many different ways in which the test data are currently presented in the literature. Thus, a uniform format for presenting pressure drop and heat transfer data for enhanced surfaces has become a necessity. This paper is concerned with one important aspect of this problem, namely, that of tubular enhanced surfaces used in shell-and-tube heat exchangers. As an initial step, the subject is limited to single-phase pressure drop and heat transfer; however, both tubeside and shellside flow are taken into consideration. A comprehensive list of commerical augmented tubes which may be considered for use in shell-and-tube exchangers is given, along with a survey of the performance data which are available in the literature. A standardized data format which uses the inside and outside envelope diameters as the basis for presenting the various geometrical, flow, and heat transfer parameters for all tubular enhanced surfaces is proposed and discussed.