skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Experimental and numerical investigation on air-side performance of fin-and-tube heat exchangers with various fin patterns

Abstract

Air-side heat transfer and friction characteristics of five kinds of fin-and-tube heat exchangers, with the number of tube rows (N = 12) and the diameter of tubes (D{sub o} = 18 mm), have been experimentally investigated. The test samples consist of five types of fin configurations: crimped spiral fin, plain fin, slit fin, fin with delta-wing longitudinal vortex generators (VGs) and mixed fin with front 6-row vortex-generator fin and rear 6-row slit fin. The heat transfer and friction factor correlations for different types of heat exchangers were obtained with the Reynolds numbers ranging from 4000 to 10000. It was found that crimped spiral fin provides higher heat transfer and pressure drop than the other four fins. The air-side performance of heat exchangers with the above five fins has been evaluated under three sets of criteria and it was shown that the heat exchanger with mixed fin (front vortex-generator fin and rear slit fin) has better performance than that with fin with delta-wing vortex generators, and the slit fin offers best heat transfer performance at high Reynolds numbers. Based on the correlations of numerical data, Genetic Algorithm optimization was carried out, and the optimization results indicated that the increase of VGmore » attack angle or length, or decrease of VG height may enhance the performance of vortex-generator fin. The heat transfer performances for optimized vortex-generator fin and slit fin at hand have been compared with numerical method. (author)« less

Authors:
; ;  [1]
  1. State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049 (China)
Publication Date:
OSTI Identifier:
21195813
Resource Type:
Journal Article
Resource Relation:
Journal Name: Experimental Thermal and Fluid Science; Journal Volume: 33; Journal Issue: 5; Other Information: Elsevier Ltd. All rights reserved
Country of Publication:
United States
Language:
English
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; HEAT TRANSFER; AIR; HEAT EXCHANGERS; REYNOLDS NUMBER; PERFORMANCE; TUBES; VORTICES; NUMERICAL DATA; OPTIMIZATION; FRICTION FACTOR; ALGORITHMS; CORRELATIONS; FINS; HEIGHT; LENGTH; PRESSURE DROP; CONFIGURATION; EVALUATION; FRICTION; Fin-and-tube heat exchanger

Citation Formats

Tang, L.H., Zeng, M., and Wang, Q.W.. Experimental and numerical investigation on air-side performance of fin-and-tube heat exchangers with various fin patterns. United States: N. p., 2009. Web. doi:10.1016/J.EXPTHERMFLUSCI.2009.02.008.
Tang, L.H., Zeng, M., & Wang, Q.W.. Experimental and numerical investigation on air-side performance of fin-and-tube heat exchangers with various fin patterns. United States. doi:10.1016/J.EXPTHERMFLUSCI.2009.02.008.
Tang, L.H., Zeng, M., and Wang, Q.W.. Wed . "Experimental and numerical investigation on air-side performance of fin-and-tube heat exchangers with various fin patterns". United States. doi:10.1016/J.EXPTHERMFLUSCI.2009.02.008.
@article{osti_21195813,
title = {Experimental and numerical investigation on air-side performance of fin-and-tube heat exchangers with various fin patterns},
author = {Tang, L.H. and Zeng, M. and Wang, Q.W.},
abstractNote = {Air-side heat transfer and friction characteristics of five kinds of fin-and-tube heat exchangers, with the number of tube rows (N = 12) and the diameter of tubes (D{sub o} = 18 mm), have been experimentally investigated. The test samples consist of five types of fin configurations: crimped spiral fin, plain fin, slit fin, fin with delta-wing longitudinal vortex generators (VGs) and mixed fin with front 6-row vortex-generator fin and rear 6-row slit fin. The heat transfer and friction factor correlations for different types of heat exchangers were obtained with the Reynolds numbers ranging from 4000 to 10000. It was found that crimped spiral fin provides higher heat transfer and pressure drop than the other four fins. The air-side performance of heat exchangers with the above five fins has been evaluated under three sets of criteria and it was shown that the heat exchanger with mixed fin (front vortex-generator fin and rear slit fin) has better performance than that with fin with delta-wing vortex generators, and the slit fin offers best heat transfer performance at high Reynolds numbers. Based on the correlations of numerical data, Genetic Algorithm optimization was carried out, and the optimization results indicated that the increase of VG attack angle or length, or decrease of VG height may enhance the performance of vortex-generator fin. The heat transfer performances for optimized vortex-generator fin and slit fin at hand have been compared with numerical method. (author)},
doi = {10.1016/J.EXPTHERMFLUSCI.2009.02.008},
journal = {Experimental Thermal and Fluid Science},
number = 5,
volume = 33,
place = {United States},
year = {Wed Jul 15 00:00:00 EDT 2009},
month = {Wed Jul 15 00:00:00 EDT 2009}
}
  • An experimental study was carried out to examine the effects of the waffle height, including three different values of waffle height--1.18, 1.32, and 1.58 mm--on the heat transfer and friction characteristics of typical fin-and-tube heat exchangers having wavy fins. A total of 13 samples of heat exchangers, nine of them having wavy fins and the other four having plan fin configurations, were tested. The test results indicated that the effect of waffle height on the heat transfer enhancement ratio, compared to the plain-fin counterpart, is pronounced only for smaller fin pitch and larger waffle height, while its effect on themore » pressure drop is considerably significant throughout the test range.« less
  • This paper deals with heat exchangers having plain fins on a staggered array of circular tubes. Correlations are developed to predict the air-side heat transfer coefficient and friction factor as a function of the Reynolds number and geometric variables of the heat exchanger such as tube diameter, tube pitch, fin spacing, etc. A multiple regression technique was used to correlate 47 sets of heat exchanger data to develop the heat transfer and friction correlation. The correlations are applicable to heat exchangers having small diameter tubes (or large tube pitch to tube diameter ratio), whose performance previous correlations failed to predictmore » adequately. The heat transfer correlation applicable to three or more row configuration predicts 94% of the data within {+-}20%, and the heat transfer correlation applicable to one- or two-row configuration predicts 94% of the data within {+-}20%. The friction correlation predicts 90% of the data within {+-}20%.« less
  • The present paper reports results from an investigation of the air side thermal performance of fin-and-tube coils with herringbone-wavy and convex-louver fins. The tube diameter of the tested coils was 12.7mm. Coils with different fin pitch and tube rows have been tested in order to determine their effect over the thermal performance. In addition, the performance of the convex-louver fins has been evaluated with respect to that of the wavy fins according to the Webb VG1 procedure. The collar diameter Reynolds number covered in the tests varied from 1000 to 6000, corresponding to face velocities of 1-6m/s. It has beenmore » found that the fin pitch affects lightly the heat transfer coefficient, its value being incremented of the order of 10% by reducing the fin pitch from 3.17mm to 1.81mm. Opposite trends have been found for the friction factor of wavy and louver fins regarding the effect of the fin pitch. The thermal performance is not affected by the number of tube rows in either of the fin configurations in coils for more than two rows. One and two row coils present non-negligible differences either with respect to the Colburn or friction factors. It has been found that area reductions in louver with respect to wavy fins can attain values of the order of 30% for Reynolds number of the order of 1000 and fin pitch of 3.17mm. (author)« less
  • Continuous rippled fins are preferred to interrupted fins in applications where fouling by fibrous matter or insects is a problem. The performance characteristic of three rippled fin heat exchangers have been measured in a thermal wind tunnel. The results of these measurements are reported and comparisons are made wtih published data on similar surfaces. The performance evaluation criteria used as the basis for the comparisons were those recommened by Shah (1978). The tested rippled fin surfaces were found to have a higher performance than a similar surface reported in Kay and London (1984). The heat transfer enhancement was found tomore » be dependent upon the profile of the fin.« less
  • A detailed analysis of experimental and numerical results for flow and heat transfer in similar offset strip-fin geometries is presented. Surface-average heat transfer and pressure drop, local Nusselt numbers and skin friction coefficients on the fin surface, instantaneous flow structures, and local time-averaged velocity profiles are contrasted for a range of Reynolds numbers using both prior and new experimental and numerical results. This contrast verifies that a two-dimensional unsteady numerical simulation captures the important features of the flow and heat transfer for a range of conditions. However, flow three-dimensionality appears to become important for Reynolds numbers greater than about 1,300,more » and thermal boundary conditions are important for Reynolds numbers below 1,000. The results indicate that boundary layer development, flow separation and reattachment, wake formation, and vortex shedding are all important in this complex geometry.« less