Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
NUMERICAL ANALYSIS OF FLOW IN A SUPERSONIC SEPARATOR NOZZLE WITH CENTRAL BODY
Submission Author:
Thomaz Faccioli , SP
Co-Authors:
Thomaz Faccioli, Reinaldo Marcondes Orselli, Ricardo Galdino da SIlva, Bruno Carmo
Presenter: Thomaz Faccioli
doi://10.26678/ABCM.COBEM2021.COB2021-0398
Abstract
The supersonic gas separator is a new technology that uses the processes of expansion and cyclonic separation to remove water and heavy hydrocarbons, such as CO2, from natural gas. In the separator design analyzed, the geometry has a central body which is used to increase the separation efficiency due to the swirling flow imposed at the inlet. The tunnel bounded by the wall and the central body forms a Laval nozzle, a cyclonic separation section and a diffuser. The fluid is accelerated in the convergent section of the Laval nozzle, then, becoming supersonic in the divergent section. There, the gas expands causing a decrease in the static pressure and temperature. As such, water and heavy hydrocarbons are condensed in the divergent section which are carried towards the wall due to the centrifugation imposed, and finally removed through the collector. The aim of this study is to carry out numerical simulations of a supersonic separator in order to investigate the main physical characteristics of this device with central body, analyzing features such as shock wave topology and position, energy losses and separation efficiency. For the numerical analyzes, the device is considered axisymmetric with a central body and a collector. In addition, the centrifugation effect is made by imposing a swirling flow at the nozzle inlet. To evaluate the capability of the separator to remove condensed particles in the divergent section, different swirl strengths as well as collector geometries are considered in this work. For the simulations, both single component and multi component gas are taken into account, with the use of methane gas as well as mixed with CO2 and air in different concentrations. In general, considering a fixed supersonic nozzle geometry, keeping the same length and area ratio, it is noted that the swirl intensity combined with the collector position are key features to set the flow to be able to perform the separation of heavier components, such as CO2.
Keywords
Computational fluid dynamics (CFD), Shockwaves, natural gas, Supersonic separators
