ANALYSIS OF TUBE BUNDLE HEAT TRANSFER TO VERTICAL FOAM FLOW

Phenomena of foam flow and associated heat transfer are rather complex. Foam is a twophase flow, which structure changes while it passes an obstacle: bubbles divide into smaller bubbles and liquid drains down from flow. Due to these peculiarities, an application of analytical methods for their study is a complex subject. Thus experimental method of investigation was selected in our work. The investigation apparatus consisted of foam generator, vertical channel and staggered bank of horizontal tubes. The cross section of the channel had square profile with side dimension 140 mm. Tubes in the bank were located in three vertical rows with five tubes in each of them. Experiments were performed within Reynolds number diapason for gas from 190 to 450 and foam void volumetric fraction from 0.996 to 0.998. Direction of foam motion in vertical channels also influences heat transfer intensity. Investigations of heat transfer process of upward and downward moving statically stable foam flow from horizontal tube bank were performed. Experimental heat transfer results of tube bundle in vertical cross foam flow were summarized by criterion equations, which enable determination of heat transfer intensity of the entire bundle or of a separate tube of the bundle for different values of void volumetric fractions and regime parameters of statically stable foam flow.

Download Full-text

Non-Condensable Gases Effect on Heat Transfer Processes Between Condensing Steam and Boiling Water in Heat Exchanger With Multirow Horizontal Tube Bundle

2010 14th International Heat Transfer Conference, Volume 4 ◽

10.1115/ihtc14-22826 ◽

2010 ◽

Cited By ~ 1

Author(s):

A. V. Morozov ◽

O. V. Remizov ◽

A. A. Tsyganok

Keyword(s):

Heat Transfer ◽

Heat Exchanger ◽

Tube Bundle ◽

Horizontal Tube ◽

Boiling Water ◽

Test Facility ◽

Primary Circuit ◽

Outer Diameter ◽

Steam Condensation ◽

Experimental Heat

The experimental investigations of non-condensable gases effect on the steam condensation inside multirow horizontal tube bundle of heat exchanger under heat transfer to boiling water were carried out at the large-scale test facility in the Institute for Physics and Power Engineering (IPPE). The experiments were carried out for natural circulation conditions in primary and secondary circuits of the facility at primary circuit steam pressure of Ps1 = 0.34 MPa. The experimental heat exchanger’s tube bundle consists of 248 horizontal coiled tubes arranged in 62 rows. Each row consists of 4 stainless steel tubes of 16 mm in outer diameter, 1.5 mm in wall thickness and of 10.2 m in length. The experimental heat exchanger was equipped with more than 100 thermocouples enabling the temperatures of primary and secondary facility circuits to be controlled in both tube bundle and in the inter-tubular space. The non-condensable gases with different density — nitrogen and helium were used in the experiments. The volumetric content of gases in tube bundle amounted to ε = 0.49. The empirical correlation for the prediction of the relative heat transfer coefficient k/k0 = f (ε) for steam condensation in steam-gas mixture was obtained.

Download Full-text

AVERAGE HEAT TRANSFER OF TUBES IN DOWNWARD FOAM FLOW

Revista de Engenharia Térmica ◽

10.5380/ret.v2i1.3518 ◽

2003 ◽

Vol 2 (1) ◽

Author(s):

J. Gylys ◽

M. Jakubcionis ◽

S. Sinkunas ◽

T. Zdankus

Keyword(s):

Heat Transfer ◽

Heat Transfer Rate ◽

Transfer Rate ◽

Liquid Velocity ◽

Tube Bundle ◽

Stable Foam ◽

Foam Flow ◽

Horizontal Tubes ◽

Tube Position ◽

Foam Generator

The model of heat exchanger was investigated experimentally. This model consists of three vertical lines of horizontal tubes with five tubes in each. Tubes were arranged in a staggered order. Heat transfer of staggered bundle of tubes to downward static stable foam flow was investigated experimentally. Heat transfer dependence on specific gas and liquid velocity was determined. Dependence of volumetric void fraction of foam on heat transfer was investigated also. Heat transfer rate dependence on tube position in the line of tube bundle was investigated experimentally. It was established that heat transfer rate highly depends on tube position in the line. Influence of tube position on heat transfer from tube bundle in upward foam flow was compared. Heat transfer dependence on tube position in the bundle was investigated experimentally also. Influence of wall of foam generator on heat transfer to sideline of tubes was established. Experimental results of heat transfer of bundle of tubes to downward static stable foam flow were generalized using dependence between Nusselt and Reynolds numbers.

Download Full-text

Experimental investigations on boiling of n-pentane across a horizontal tube bundle: two-phase flow and heat transfer characteristics

International Journal of Refrigeration ◽

10.1016/s0140-7007(99)00021-3 ◽

1999 ◽

Vol 22 (7) ◽

pp. 536-547 ◽

Cited By ~ 25

Author(s):

R. Roser ◽

B. Thonon ◽

P. Mercier

Keyword(s):

Heat Transfer ◽

Two Phase Flow ◽

Tube Bundle ◽

Horizontal Tube ◽

Experimental Investigations ◽

Phase Flow ◽

Heat Transfer Characteristics ◽

Two Phase ◽

Transfer Characteristics ◽

Flow And Heat Transfer

Download Full-text

Experimental investigation of the heat transfer process between a tube bundle and an upward aqueous foam flow

Advanced Computational Methods and Experiments in Heat Transfer XI ◽

10.2495/ht100021 ◽

2010 ◽

Author(s):

J. Gylys ◽

T. Zdankus ◽

S. Sinkunas ◽

M. Babilas ◽

R. Jonynas

Keyword(s):

Heat Transfer ◽

Experimental Investigation ◽

Transfer Process ◽

Tube Bundle ◽

Heat Transfer Process ◽

Foam Flow ◽

Aqueous Foam

Download Full-text

AVERAGE HEAT TRANSFER OF TUBES IN DOWNWARD FOAM FLOW

Revista de Engenharia Térmica ◽

10.5380/reterm.v2i1.3518 ◽

2003 ◽

Vol 2 (1) ◽

pp. 38

Author(s):

J. Gylys ◽

M. Jakubcionis ◽

S. Sinkunas ◽

T. Zdankus

Keyword(s):

Heat Transfer ◽

Heat Transfer Rate ◽

Transfer Rate ◽

Liquid Velocity ◽

Tube Bundle ◽

Stable Foam ◽

Foam Flow ◽

Horizontal Tubes ◽

Tube Position ◽

Foam Generator

The model of heat exchanger was investigated experimentally. This model consists of three vertical lines of horizontal tubes with five tubes in each. Tubes were arranged in a staggered order. Heat transfer of staggered bundle of tubes to downward static stable foam flow was investigated experimentally. Heat transfer dependence on specific gas and liquid velocity was determined. Dependence of volumetric void fraction of foam on heat transfer was investigated also. Heat transfer rate dependence on tube position in the line of tube bundle was investigated experimentally. It was established that heat transfer rate highly depends on tube position in the line. Influence of tube position on heat transfer from tube bundle in upward foam flow was compared. Heat transfer dependence on tube position in the bundle was investigated experimentally also. Influence of wall of foam generator on heat transfer to sideline of tubes was established. Experimental results of heat transfer of bundle of tubes to downward static stable foam flow were generalized using dependence between Nusselt and Reynolds numbers.

Download Full-text

Boiling Heat Transfer From a Horizontal Tube in an Upward Flowing Two-Phase Crossflow

Journal of Heat Transfer ◽

10.1115/1.3246762 ◽

1984 ◽

Vol 106 (4) ◽

pp. 849-855 ◽

Cited By ~ 11

Author(s):

M. E. Wege ◽

M. K. Jensen

Keyword(s):

Heat Transfer ◽

Vertical Channel ◽

Horizontal Tube ◽

Nucleate Boiling ◽

Working Fluid ◽

Transfer Coefficients ◽

Two Phase ◽

Average Deviation ◽

Wall Superheat ◽

Two Phase Heat Transfer

An experimental investigation has been performed to determine the effects of a low-quality (≤ 20 percent) upward flowing mixture on the nucleate boiling on a single horizontal lube. An electrically heated, 12.7-mm-dia tube was centered in a plane wall vertical channel, the width of which resulted in channel width-to-tube diameter ratios (w/d) of 1.16 and 1.95. The working fluid was R-113. The two-phase heat transfer data showed a variety of effects. For a fixed w/d, pressure (P), and quality (x), the average heat transfer coefficients (h) increased with increasing mass velocity (G), but the effect of G decreased as the wall superheat (ΔT) increased. For a fixed w/d, G and x, h increased as the pressure increased except at low ΔT’s where the reverse was found. For fixed w/d, P and G, h increased with increasing quality with the effect appearing to be more pronounced at the lower pressure. At a fixed P, G and x, h was at larger w/d ratios at small ΔT’s, but as the wall superheat increased an inversion occured and h became smaller at the larger w/d ratio. The behavior exhibited in this experiment can be explained in terms of the velocity of the fluid flowing past the test section. The data were successfully predicted to within an average deviation of ±11.6 percent using a Chen-type correlation. Data from the literature also were predicted well.

Download Full-text