Experimental study of pure steam and steam–air condensation over a vertical corrugated tube

The current study experimentally investigates the heat transfer augmentation on the novel axial corrugated heat exchanger tube in which the spring tape is introduced. Air (Pr = 0.707) is used as a working fluid. In order to augment the thermohydraulic performance, a corrugated tube with inserts is offered. The experimental study is further extended by varying the important parameters like spring ratio (y = 1.5, 2.0, 2.5) and Reynolds number (Re = 10 000–52 000). The angular pitch between the two neighboring corrugations and the angle of the corrugation is kept constant through the experiments at β = 1200 and α = 600 respectively, while two different corrugations heights (h) are analyzed. While increasing the corrugation height and decreasing the spring ratio, the impact of the swirling effect improves the thermal performance of the system. The maximum thermal performance is obtained when the corrugation height is h = 0.2 and spring ratio y = 1.5. Eventually, correlations for predicting friction factor (f) and Nusselt number (Nu) are developed.

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Crashworthiness Analysis of a Novel Aluminum Bi-tubular Corrugated Tube—Experimental Study

Lecture Notes in Mechanical Engineering - Advances in Manufacturing Processes ◽

10.1007/978-981-13-1724-8_55 ◽

2018 ◽

pp. 599-607 ◽

Cited By ~ 11

Author(s):

Arameh Eyvazian ◽

Sara Najafian ◽

Hozhabr Mozafari ◽

A. Praveen Kumar

Keyword(s):

Experimental Study ◽

Corrugated Tube ◽

Crashworthiness Analysis

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Comparative Experimental Study on Performance of Corrugated Tube and Straight Tube Heat Exchanger

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.560-561.156 ◽

2012 ◽

Vol 560-561 ◽

pp. 156-160

Author(s):

Lin Ping Lu ◽

Liang Ying

Keyword(s):

Heat Transfer ◽

Experimental Study ◽

Heat Exchanger ◽

Pressure Drop ◽

Heat Exchangers ◽

Straight Tube ◽

Lower Stress ◽

Shell Side ◽

Tube Heat Exchanger ◽

Corrugated Tube

The experiments on heat transfer coefficient, pressure drop and thermal stress were done to heat exchangers with corrugated tubes and staight tubes. By analyising and comparing the heat transfer coeffient, pressure drop in tube side and shell side and axial force and stress, some conclusions can be conducted that the corrugated tube heat exchanger has better heat transfer coeffient, higher pressure drop and much lower stress caused by temperatur difference, also, it has obvious advantages under the circumstance of low Reynolds number and high temperature difference.

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Experimental Study of Film Condensation From Steam-Air Mixtures Flowing Downward Over a Horizontal Tube

Journal of Heat Transfer ◽

10.1115/1.3450145 ◽

1974 ◽

Vol 96 (1) ◽

pp. 83-88 ◽

Cited By ~ 5

Author(s):

J. W. Rauscher ◽

A. F. Mills ◽

V. E. Denny

Keyword(s):

Heat Transfer ◽

Experimental Study ◽

Theoretical Analysis ◽

Mass Fraction ◽

Horizontal Tube ◽

Forced Flow ◽

Film Condensation ◽

Air Mass ◽

Average Value ◽

Pure Steam

Experiments have been performed to study the effects of air on filmwise condensation from steam-air mixtures undergoing forced flow over a 3/4 in. OD horizontal tube. Local condensation rates at the stagnation point are reported for saturation temperatures of 100–150 deg F, bulk to wall temperature differences of 3–30 deg F, bulk air mass fraction 0–7 percent and oncoming vapor velocity 1–6 ft/sec. For pure steam the average value of q/qNu, where qNu is the Nusselt result, was 0.98 ± 0.10, which compares favorably with the value of 1.04 predicted by a theory which accounts for vapor drag. For steam-air mixtures the reduction in heat transfer was found to be in excellent agreement with the theoretical analysis of Denny and South; the average discrepancy in q/qNu was −2.7 percent, while the maximum was 7.1 percent.

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