Two Phase Flow: Accounting for the Presence of Liquids in Gas Pipeline Design

2004 ◽  
Author(s):  
Ben Asante
Keyword(s):  
Multiphase Flow ◽  
Liquid Film ◽  
Friction Factor ◽  
Experimental Studies ◽  
Small Diameter ◽  
Gas Pipeline ◽  
Experimental Investigations ◽  
Two Phase ◽  
Flow Area ◽  
Operating Data

Multiphase flow of gas and low loads of liquids occurs frequently in natural gas gathering and transmission pipelines for both onshore and offshore operations. Literature and experimental investigations indicate that dispersed droplet and stratified flow patterns are obtained when gas and small quantities of liquids flow concurrently in a pipe. Very few correlations exist for the prediction of holdup and pressure drop for these systems and fewer still give satisfactory results. Experimental studies for air-oil and airwater systems flowing through small diameter plastic and steel horizontal pipes ranging in size from 1-inch to 3-inches were performed. The experiments were carried out at the multiphase flow laboratories of Imperial College in London and the University of Calgary in Canada. Data from actual operating gas pipeline systems transporting small amounts of hydrocarbon liquids were also evaluated. Based on the experimental results and the operating data, two approaches for modeling these systems are proposed: 1) A homogeneous approach for very low liquid loads (holdups up to 0.005), typical in gas transmission systems. A friction factor correlation based on the holdup has been developed for this flow regime. 2) A mechanistic stratified two-phase approach for higher liquid loads (holdups greater than 0.005) usually found in gas gathering systems with consideration given to: a) The reduction in the available flow area and extent of wetting of the pipe perimeter by the liquid film. The gas/liquid interface was observed to be either flat or curved. b) The interfacial friction factor between the liquid film and the gas. A new correlation based on the liquid and gas Reynolds numbers as well as the film thickens and hold up has been developed. This correlation has been successfully tested against both experimental and actual pipeline operating data.

scholarly journals Experimental and theoretical study of dryout in annular flow in small diameter channels

2011 ◽  
Vol 32 (1) ◽  
pp. 89-108 ◽  
Author(s):  
Dariusz Mikielewicz ◽  
Michał Gliński ◽  
Jan Wajs
Keyword(s):  
Experimental Data ◽  
Liquid Film ◽  
Annular Flow ◽  
Theoretical Study ◽  
Small Diameter ◽  
Infrared Camera ◽  
Equation Model ◽  
Internal Diameter ◽  
Two Phase ◽  
Liquid Film Dryout

Experimental and theoretical study of dryout in annular flow in small diameter channels In the paper the experimental analysis of dryout in small diameter channels is presented. The investigations were carried out in vertical pipes of internal diameter equal to 1.15 mm and 2.3 mm. Low-boiling point fluids such as SES36 and R123 were examined. The modern experimental techniques were applied to record liquid film dryout on the wall, among the others the infrared camera. On the basis of experimental data an empirical correlation for predictions of critical heat flux was proposed. It shows a good agreement with experimental data within the error band of 30%. Additionally, a unique approach to liquid film dryout modeling in annular flow was presented. It led to the development of the three-equation model based on consideration of liquid mass balance in the film, a two-phase mixture in the core and gas. The results of experimental validation of the model exhibit improvement in comparison to other models from literature.

Annular Flow Experimental Study in Horizontal Pipes Using Radial Proximity Probes

2008 ◽  
Author(s):  
Domitilo Libreros ◽  
F. Sa´nchez Silva ◽  
I. Carvajal Mariscal ◽  
G. Polupan
Keyword(s):  
Time Series ◽  
Liquid Film ◽  
Digital Signal Processor ◽  
Annular Flow ◽  
Experimental Studies ◽  
Digital Signal ◽  
Flow Region ◽  
Measuring System ◽  
Two Phase ◽  
Signal Processor

The development of a new technique to detect and measure the annular flow parameters is presented in this article, the liquid film thickness was detected and measured in eight different radial positions, and the experimental information obtained was used to analyze the liquid film behaviour in order to set the wall regions where the probability to dry is higher. For the above purpose, a measuring system was developed, it was formed by a Digital Signal Processor (DSP) and a proximity circuit based on the embedded technology, it was also implemented a calibration methodology based on the Mandhane map to set the annular flow region in the experimental set up. The Digital Signal Processor (DSP) was also used to interpret and construct the signals according to its time and frequency behaviour. Due to its capacity of making complex operations, including its programming in C language, the device becomes an excellent real time tool to observe and quantify this phenomenon. The measuring and description of the annular flow is carried out through a digital camera, getting time series and visual patterns, creating a data base with hundreds of tests from the experimental system. The liquid film time series are interpreted through lineal transformation with Fourier series, where they are analyzed controlling the frequency and time. Subsequently, they are compared with the original signals to detect measurements uncertainty. The measuring prototype is full described for future applications in the instrumentation and control of the two-phase and multiphase flows experimental studies.

scholarly journals Numerical Simulation of Falling Liquid Film Flow on a Vertical Plane by Two-Phase Lattice Boltzmann Method

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Andreas Hantsch ◽  
Ulrich Gross
Keyword(s):  
Liquid Film ◽  
Lattice Boltzmann ◽  
Film Flow ◽  
Experimental Studies ◽  
Vertical Plane ◽  
Navier Stokes ◽  
Two Phase ◽  
Lattice Boltzmann Methods ◽  
Falling Liquid Film ◽  
Liquid Film Flow

Falling liquid film flow is widely used in many processes. Supplementary to experimental studies, Navier-Stokes-based models have been employed for describing film flow phenomena. These models are often disadvantageous since they are either strongly limited in their generality or need enormous computational resources. In this investigation, a new approach is proposed for modelling flow by lattice Boltzmann methods. Therefore, the well-known Shan-Chen model (Shan and Chen, 1993) has been employed to an isothermal falling liquid film. The validity of the implementation has been checked against some single-phase and two-phase reference cases. Test series have been conducted for three different Reynolds numbers without external disturbances and for one Reynolds number with sinusoidally pulsating inlet velocity. The computational results show that lattice Boltzmann methods are capable to model falling liquid film flow and that the flow morphology is in qualitatively good agreement with other numerical and experimental works.

Parametric Study of a Thermosyphon Loop Pressure Drop Model

2004 ◽  
Author(s):  
Jinsong Zhang ◽  
Jason Hugenroth ◽  
Issam Mudawar ◽  
Timothy S. Fisher
Keyword(s):  
Heat Flux ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Flow Boiling ◽  
Current System ◽  
Experimental Studies ◽  
Two Phase ◽  
Flow Area ◽  
Cross Sectional

A closed loop two-phase thermosyphon has been modeled based on earlier experimental and numerical studies by Mukherjee and Mudawar [1, 2]. Unlike conventional thermosyphons in which the heat dissipating device is submerged in a pool of liquid coolant, the current system uses a flow boiling arrangement. The advantage is that for a given boiling surface area, the critical heat flux (CHF) can be increased. Parametric studies with respect to adiabatic section flow areas, boiler section flow area, and system height were performed. The maximum practical heat flux that is attainable is predicted, as well as other flow parameters such as mass flow rate, flow velocities and fluid quality existing the boiler. Performance enhancements relative to the original system, may be possible by introducing a divergent cross sectional area in the boiler section that increases the system mass flow rate. It can also, however, reduce the flow velocity in certain sections of the boiler, tending to reduce the boiler CHF. Experimental studies are recommended to determine if an actual improvement can be realized.

scholarly journals Experimental Evaluation of Airlift Performance for Vertical Pumping of Water in Underground Mines

2021 ◽  
Author(s):  
Parviz Enany ◽  
Oleksandr Shevchenko ◽  
Carsten Drebenstedt
Keyword(s):  
Water Flow ◽  
High Efficiency ◽  
Experimental Studies ◽  
Theoretical Models ◽  
Injection System ◽  
Experimental Investigations ◽  
Flow Mode ◽  
New Device ◽  
Riser Pipe ◽  
Airlift Pump

AbstractThis paper presents experimental studies on the optimization of air–water flow in an airlift pump. Airlift pumps use compressed gas to verticall transport liquids and slurries. Due to the lack of theoretical equations for designing and predicting flow regimes, experimental investigations must be carried out to find the best condition to operate an airlift pump at high efficiency. We used a new air injection system and different submergence ratios to evaluate the output of a simple pump for vertical displacement of water in an underground mine. The tests were carried out in a new device with 5.64 m height and 10.2 cm circular riser pipe. Three air-jacket pipes, at different gas flows in the range of 0.002–0.09 m3/s were investigated with eight submergence ratios. It was found that with the same air flow rate, the most efficient flow of water was achieved when an air jacket with 3 mm diameter holes was used with a submergence ratio between 0.6 and 0.75. In addition, a comparison of practical results with two theoretical models proposed by other investigators showed that neither was able to accurately predict airlift performance in air–water flow mode.

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