Heat transfer enhancement in annular channels with helical and longitudinal fins

Journal Article · Sat Apr 01 04:00:00 EST 1995 · Heat Transfer Engineering

DOI:https://doi.org/10.1080/01457639508939850· OSTI ID:128762

Joye, D D; Cote, A S ^[1]

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1. Villanova Univ., PA (United States). Dept. of Chemical Engineering

Heat exchange in an annulus with and without fins was investigated. Two helical fin arrangements and a comparable area, multi flight, longitudinal fin design were compared to the plain annulus without fins. All experiments were done in the same shell, hence the same volume space, derived from a commercial heat reclaimer unit. Film heat transfer coefficients (h) for the annular flow ere calculated from experimental data. The results show that enhancement in annular heat transfer coefficient for both helical arrangements (conducting and nonconducting fin) was 40--50%, thus the film coefficient was essentially the same on both fin and curved surfaces. The film coefficients were also the same for the longitudinal fins and the plain annulus cases, but the enhancement was 260%, much higher than expected. The authors believe the reasons for this are the short L/D of the annulus coupled with a predominant entrance/exit ``cross-flow`` effect; thus, short annular exchangers of this type may give very high enhancements as a general rule.

• Sponsoring Organization: USDOE
• OSTI ID: 128762
• Journal Information: Heat Transfer Engineering, Journal Name: Heat Transfer Engineering Journal Issue: 2 Vol. 16; ISSN 0145-7632; ISSN HTEND2
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
AUGMENTATION
HEAT RECOVERY
HEAT TRANSFER
WASTE HEAT BOILERS
WASTE HEAT UTILIZATION