Modeling of Hydrate Deposition in Loading and Offloading Flowlines of Marine CNG Systems
Issue:
Volume 3, Issue 6-1, December 2014
Pages:
1-6
Received:
29 November 2014
Accepted:
3 December 2014
Published:
13 February 2015
DOI:
10.11648/j.ijrse.s.2014030601.11
Downloads:
Views:
Abstract: The main aim of this paper is to demonstrate the prediction of the model capability of predicting the nucleation process, the growth rate, and the deposition potential of hydrate particles in gas flowlines. The primary objective of the research is to predict the risk hazards involved in the marine transportation of compressed natural gas. However the proposed model can be equally used for other applications including production and transportation of natural gas in any high pressure flowline. The proposed model employs the following three main components to approach the problem: computational fluid dynamics (CFD) technique is used to configure the flow field; the nucleation model is developed and incorporated in the simulation to predict the incipient hydrate particles size and growth rate; and the deposition of the gas/particle flow is proposed using the concept of the particle deposition velocity. These components are integrated in comprehended model to locate the hydrate deposition in natural gas flowlines. The present research is prepared to foresee the hydrate deposition location that could occur in a real application in Compressed Natural Gas loading and offloading. A pipeline with 120 m length and different sizes carried a natural gas is taken in the study. The location of hydrate deposition formed as a result of restriction is determined based on the procedure mentioned earlier and the effect of water content and downstream pressure is studied. The critical flow speed that prevents hydrate to accumulate in the certain pipe length is also addressed.
Abstract: The main aim of this paper is to demonstrate the prediction of the model capability of predicting the nucleation process, the growth rate, and the deposition potential of hydrate particles in gas flowlines. The primary objective of the research is to predict the risk hazards involved in the marine transportation of compressed natural gas. However ...
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Generalized Deposition Model of Tiny Solid Particle Immersed in Turbulent Flow
Issue:
Volume 3, Issue 6-1, December 2014
Pages:
7-14
Received:
29 November 2014
Accepted:
3 December 2014
Published:
13 February 2015
DOI:
10.11648/j.ijrse.s.2014030601.12
Downloads:
Views:
Abstract: Progress to the correlation of particle deposition velocity in turbulent pipe flow is presented. The developed model accounts for the Brownian diffusivity and inertia effects and is extended to cover the influence of the flow velocity by including Reynolds number in the correlation. The experimental data and previous proposed models are used in comparison of predicting particle deposition rate. It is shown that the new model of deposition velocity is in good agreement with the experimental data and numerical simulations. Further the aerodynamics has significant influence on the deposition rate and should be concerned when the process of particle migration and deposition is addressed. The deposition efficiency, the measurement tool of particle deposition rate in this work, increases with the increase of diameter for large particles, and with the decrease of diameter for submicron particles. Other factors addressed in this work are effects of particle to fluid density ratio, pipe diameter and the surface roughness. The results showed that increase in density ratio makes the deposition rate of submicron particles to increase too whereas no significant effects is noticed for large particles. Carrier pipe size is studied and the deposition rate curve shifts right with decreasing in pipe size. Finally, the deposition rate of particles is found to increase with increase in surface roughness.
Abstract: Progress to the correlation of particle deposition velocity in turbulent pipe flow is presented. The developed model accounts for the Brownian diffusivity and inertia effects and is extended to cover the influence of the flow velocity by including Reynolds number in the correlation. The experimental data and previous proposed models are used in com...
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