A Relation Between Two-Phase Pressure Drop and Flow Distribution in a Compact Heat Exchanger Header

2004 ◽  
Author(s):  
Jong-Soo Kim ◽  
Ki-Taek Lee ◽  
Jae-Hong Kim ◽  
Soo-Jung Ha ◽  
Yong-Bin Im
Keyword(s):  
Experimental Study ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Single Phase ◽  
Small Diameter ◽  
Flow Distribution ◽  
Compact Heat Exchanger ◽  
Phase Flow ◽  
Two Phase ◽  
Phase Pressure

In this paper an experimental study was performed for relation between two-phase pressure drop and flow distribution in compact heat exchanger using small diameter tubes. We performed the experimental study in non-heating mode. A test section was consisted of the horizontal header (circular tube: φ 5 mm × 80 mm) and 10 upward circular channels (φ 1.5 mm × 850 mm) using acrylic tube. Three different types of tube insertion depth were tested for the mass flux and inlet quality ranging from of 50–200 kg/m2s and 0.1–0.3, respectively. Air and water were used as the test fluids. Two-phase pressure drop of each channel and three type of distribution header was measured. As whole, single-phase and two-phase, pressure drop in rear channel is found to be lower than that in front channel. In conclusion, we can claim that principle of distribution is almost same pressure drop in each channel. Comparing pressure drop in branch tube with correlation equation, it was found that in single-phase flow, experimental value was 10% lower than Hagen-Poiseuille, Blasius equation (Eq. 40) in two-phase flow.

Single phase pressure drop and two-phase distribution in an offset strip fin compact heat exchanger

2012 ◽  
Vol 49 ◽  
pp. 99-105 ◽  
Author(s):  
Selma Ben Saad ◽  
Patrice Clément ◽  
Jean-François Fourmigué ◽  
Caroline Gentric ◽  
Jean-Pierre Leclerc
Keyword(s):  
Heat Exchanger ◽  
Pressure Drop ◽  
Single Phase ◽  
Phase Distribution ◽  
Compact Heat Exchanger ◽  
Two Phase ◽  
Offset Strip Fin ◽  
Phase Pressure

Two-Phase Flow Distribution in a Compact Heat Exchanger Header

2003 ◽  
Author(s):  
Jong-Soo Kim ◽  
Yong-Bin Im ◽  
Jae-Hong Kim ◽  
Ki-Taek Lee
Keyword(s):  
Heat Exchanger ◽  
Two Phase Flow ◽  
Phase Distribution ◽  
Flow Distribution ◽  
Compact Heat Exchanger ◽  
Phase Flow ◽  
Two Phase ◽  
Insertion Depth ◽  
Different Types ◽  
Uniform Liquid

In this paper an experimental study was investigated for two-phase distribution in compact heat exchanger header. A test section was consisted of the horizontal header (circular tube: φ 5 mm × 80 mm) and 10 upward circular channels (φ 1.5 mm × 850 mm) using acrylic tube. Three different types of tube insertion depth were tested for the mass flux and inlet quality ranges of 50–200 kg/m2s and 0.1–0.3, respectively. Air and water were used as the test fluids. The distribution of vapor and liquid is obtained by measurement of the total mass flow rate and the calculation of the quality. Two-phase flow pattern was observed, and pressure drop of each channel was measured. By adjusting the insertion depth of each channel a uniform liquid flow distribution through the each channel was able to solve the mal-distribution problem.

Single- and two-phase pressure drop through vertical Venturis

2020 ◽  
Vol 234 (12) ◽  
pp. 2349-2359 ◽  
Author(s):  
Abdelkader Messilem ◽  
Abdelwahid Azzi ◽  
Ammar Zeghloul ◽  
Faiza Saidj ◽  
Hiba Bouyahiaoui ◽  
...  
Keyword(s):  
Pressure Drop ◽  
High Reynolds Number ◽  
Single Phase ◽  
Area Ratio ◽  
Superficial Velocity ◽  
Phase Flow ◽  
Single Phase Flow ◽  
Two Phase ◽  
High Reynolds ◽  
Phase Pressure

An experimental investigation of the pressure drops measurements in a Venturi placed in a vertical pipe is achieved. Venturis with diameter ratios equal to 0.4, 0.55, and 0.75 were employed. Differential pressure transducers were used to measure the pressure drop between the Venturi inlet and the throat sections. The void fraction was measured upstream the Venturi using a conductance probe technique. Air and water superficial velocities ranges were chosen to cover single-phase flow and bubbly, slug, and churn flow regimes. The single-phase pressure drop increases with the liquid superficial velocity. The Venturi pressure drop coefficient increases with decreasing the Venturi area ratio. The discharge coefficient increases slightly with this ratio and approaches a value of unity at high Reynolds number. The two-phase flow pressure drop and the multiplier coefficient increase with the gas superficial velocity and with decreasing the area ratio. Dimensionless pressure drop decreases with increasing the liquid to gas superficial velocity ratio and approaches an asymptotic value at high ratio (greater than 10). This value matches the single-phase flow dimensionless pressure drop value at high Reynolds number. The Venturi with area ratio equal to 0.55 was shown to correlate well the two-phase multiplier and the liquid holdup.

The Influence of Header Design on Two-Phase Flow Distribution in Plate-Fin Heat Exchangers

2020 ◽  
Vol 13 (2) ◽  
Author(s):  
Zhe Zhang ◽  
Sunil Mehendale ◽  
Shengnan Lv ◽  
Hui Yuan ◽  
JinJin Tian
Keyword(s):  
Heat Exchanger ◽  
Water Flow ◽  
Heat Exchangers ◽  
Water Distribution ◽  
Single Phase ◽  
Two Phase Flow ◽  
Flow Distribution ◽  
Phase Flow ◽  
Single Phase Flow ◽  
Two Phase

Abstract Fluid flow maldistribution causes deterioration of heat transfer as well as pressure drop penalty in heat exchangers. A test bench was set up to investigate the effect of different header designs on air-water flow distribution in plate-fin heat exchangers (PFHX). Two-phase flow distribution was examined for air Reynolds numbers (ReG) of 28293542 and inlet qualities (x) of 46.3–64.0%. Two-phase flow distribution was seen to be more uneven in the heat exchanger in comparison with single-phase flow, the water distribution being more uneven than that of the air. For a fixed inlet quality, as the air flowrate was increased, the distribution of two-phase flow became increasingly nonuniform, showing a pattern similar to single-phase flow. Furthermore, the air distribution became more even, while the water flow became more unevenly distributed as the inlet quality increased. To mitigate the maldistribution, perforated plates were incorporated in the heat exchanger header. The improved headers significantly aided in distributing the two-phase flow more evenly. At ReG = 2829 and x = 46.3%, the heat exchanger effectiveness was expressed in terms of the unevenness in quality, Sx. The effectiveness decreased as the unevenness of the flow distribution was exacerbated, emphasizing the significance of uniform phase and flow distribution as a key element of heat exchanger design.

scholarly journals An experimental study on two-phase pressure drop in small diameter horizontal, downward inclined and vertical tubes

2015 ◽  
Vol 19 (5) ◽  
pp. 1791-1804 ◽  
Author(s):  
Arun Autee ◽  
Srinivasa Rao ◽  
Ravikumar Puli ◽  
Ramakant Shrivastava
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Pressure Drop ◽  
Small Diameter ◽  
Working Fluid ◽  
Water Mixture ◽  
Two Phase ◽  
New Correlation ◽  
Vertical Tubes ◽  
Phase Pressure

An experimental study of two-phase pressure drop in small diameter tubes orientated horizontally, vertically and at two other downward inclinations of ?= 300 and ? = 600 is described in this paper. Acrylic transparent tubes of internal diameters 4.0, 6.0, and 8.0 mm with lengths of 400 mm were used as the test section. Air-water mixture was used as the working fluid. Two-phase pressure drop was measured and compared with the existing correlations. These correlations are commonly used for calculation of pressure drop in macro and mini-microchannels. It is observed that the existing correlations are inadequate in predicting the two-phase pressure drop in small diameter tubes. Based on the experimental data, a new correlation has been proposed for predicting the two-phase pressure drop. This correlation is developed by modification of Chisholm parameter C by incorporating different parameters. It was found that the proposed correlation predicted two-phase pressure drop at satisfactory level.

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