Study on Gas-Liquid Two-Phase Flow Distribution Inside a Flute Header

2020 ◽  
Author(s):  
Liping Pang ◽  
Shangmin Li ◽  
Hu Yuan ◽  
Liqiang Duan
Keyword(s):  
Liquid Phase ◽  
Gas Phase ◽  
Liquid Flow ◽  
Two Phase Flow ◽  
Phase Distribution ◽  
Flow Distribution ◽  
Phase Flow ◽  
Two Phase ◽  
Parallel Channels ◽  
Gas Liquid Flow

Abstract When the supercritical boiler is working at low load during flexible operation, the uneven distribution of the gas-liquid flow at the intermediate header may affect the safety of the water-cooled wall at the vertical parallel panels. In order to improve the uniformity of gas-liquid flow distribution in the water-cooled wall of intermediate header and study the internal flow mechanism, a flute inside the header is applied with parallel vertical parallel channels and experiments under different operating conditions are conducted to verify the effectiveness of this geometrical structure. The flow pattern in the experiment belongs to stratified and wavy flow. Computational fluid dynamic (CFD) simulation is conducted in order to investigate two-phase flow distribution behavior inside a flute header. It was found that the radial gas phase distribution in the flute tube shows a symmetrical relationship, and there are two vortexes in opposite directions. With the increasing distance from the inlet, the uniformity of the gas phase distribution becomes even. The gravity is greater than the drag force, which has effect on the two-phase flow distribution. The gas phase velocity has been improved inside flute section and liquid phase flow has more even flow distribution along annular section. It makes liquid phase sent to far end of flute header. That benefits two-phase flow distribution along 10 parallel channels equally.

Behavior of the Two-Phase Gas-Liquid Flow at the Inlet of a Catalytic Reactor

2019 ◽  
Vol 19 (2) ◽  
pp. 123-131
Author(s):  
O. P. Klenov ◽  
A. S. Noskov
Keyword(s):  
Liquid Phase ◽  
Uniform Distribution ◽  
Liquid Flow ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Catalytic Reactor ◽  
Two Phase ◽  
Gas Consumption ◽  
Flow Diagrams ◽  
Gas Liquid Flow

The work was aimed at studying the behavior of the two-phase gas-liquid flow at the inlet pipe of a catalytic reactor. Apart from the classical approach using literature flow diagrams, methods of computational hydrodynamics were used for 3D simulation of the space propagation of phases in the pipeline. The results obtained demonstrated non-uniform distribution of the liquid phase through the outlet section of the pipeline and the time-unsteady mass consumption of the liquid phase. The maximal peak consumptions were ca. 3 times as high as the average values. With the data on the flow diagrams, the CFD simulation demonstrated that variations in the gas consumption within the range under study do not cause changes in the behavior of the two-phase flow but an increase in the gas consumption results in smoothening of the non-uniform distribution of the liquid phase at the outlet pipe. The data on the flow behavior are necessary for designing catalytic reactors to provide uniform propagation of the two-phase flow over the catalyst bed, for example, hydrotreatment reactors used in refineries.

scholarly journals Complexity of phase distribution in two-phase flow using composite multiscale entropy

2020 ◽  
Vol 135 (8) ◽  
Author(s):  
Gabriela Rafałko ◽  
Romuald Mosdorf ◽  
Grzegorz Litak ◽  
Grzegorz Górski
Keyword(s):  
Gas Phase ◽  
Two Phase Flow ◽  
Phase Distribution ◽  
Digital Camera ◽  
Flow Distribution ◽  
Multiscale Entropy ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Rates ◽  
Water Glycerol

AbstractMultiphase flow in a minichannel is a complex phenomenon which shows various patterns dynamics including slugs and bubbles depending on gas/fluid component flow rates. In this paper, air and water–glycerol mixed fluid flow has been studied. In the experiment, the volume flow rates of air and water–glycerol were changing. We studied transition of bubbles to slugs two-phase flow patterns by using multiscale entropy approach to digital camera signals and identified various patterns. The results clearly indicate that the multiscale entropy is an important complexity measure dependent on the flow distribution of the gas phase in a water–glycerol content.

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.

Numerical Simulation of the Gas-Liquid Flow in a Rotary Gas Separator

1998 ◽  
Vol 120 (1) ◽  
pp. 41-48 ◽  
Author(s):  
G. Lackner ◽  
F. J. S. Alhanati ◽  
S. A. Shirazi ◽  
D. R. Doty ◽  
Z. Schmidt
Keyword(s):  
Void Fraction ◽  
Liquid Flow ◽  
Two Phase Flow ◽  
Numerical Procedure ◽  
Phase Flow ◽  
Two Phase ◽  
Free Gas ◽  
Gas Separator ◽  
Gas Liquid Flow ◽  
Gas Void Fraction

The presence of free gas at the pump intake adversely affects the performance of an electrical submersible pump (ESP) system, often resulting in low efficiency and causing operational problems. One method of reducing the amount of free gas that the pump has to process is to install a rotary gas separator. The gas-liquid flow associated with the down hole installation of a rotary separator has been investigated to address its overall phase segregation performance. A mathematical model was developed to investigate factors contributing to gas-liquid separation and to determine the efficiency of the separator. The drift-flux approach was used to formulate this complex two-phase flow problem. The turbulent diffusivity was modeled by a two-layer mixing-length model and the relative velocity between phases was formulated based on published correlations for flows with similar characteristics. The well-known numerical procedure of Patankar-Spalding for single-phase flow computations was extended to this two-phase flow situation. Special discretization techniques were developed to obtain consistent results. Special under relaxation procedures were also developed to keep the gas void fraction in the interval [0, 1]. Predicted mixture velocity vectors and gas void fraction distribution for the two-phase flow inside the centrifuge are presented. The model’s predictions are compared to data gathered on a field scale experimental facility to support its invaluable capabilities as a design tool for ESP installations.

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