Citation: Kou, J.; Li, Z. Numerical
Simulation of New Axial Flow
Gas-Liquid Separator. Processes 2022,
10, 64. https://doi.org/10.3390/
pr10010064
Academic Editors: Arkadiusz Gola,
Izabela Nielsen and Patrik Grznár
Received: 4 December 2021
Accepted: 21 December 2021
Published: 29 December 2021
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Article
Numerical Simulation of New Axial Flow Gas-Liquid Separator
Jie Kou * and Zhaoyang Li
College of Pipeline and Civil Engineering, China University of Petroleum (East China), Qingdao 266580, China;
lizylicy@126.com
* Correspondence: koujie@upc.edu.cn
Abstract:
At present, most of the incoming liquids from the oilfield combined stations are not pre-
separated for natural gas, which makes the subsequent process of oil-water separation less effective.
Therefore, it is necessary to carry out gas-liquid separation. A new type of axial flow gas-liquid
separator was proposed in this paper. The numerical simulation was carried out by CFD FLUENT
software, and the changes of concentration field, velocity field and pressure field in the axial flow
gas-liquid separator were analyzed. It was found that there were gas-liquid separation developments
and stabilization segments in the inner cylinder of the separator. The axial velocity will form a
zero-speed envelope in the inner cylinder, and the direction of the velocity in front of and behind the
zero-speed envelope was opposite. The tangential velocity showed a “W” shape distribution in the
radial position of the inner cylinder. The pressure on the left wall of the guide vane was higher than
that on the right side. Therefore, the left wall was more likely to be damaged than the right wall.
Keywords: velocity field; “W” shape distribution; zero-speed envelope
1. Introduction
As early as in the 1980s, scholars at home and abroad began to carry out theoretical
and experimental research on cyclone separators [
1
–
4
]. The main principle of a cyclone
separator is when the fluid passes through the cyclone will generate a large centrifugal
force, due to the density difference between the phases of the mixture, under the action
of centrifugal force, the less dense phase will gather in the central area, and the denser
phase will move to the outside, so as to achieve separation. There are generally two types
of gas-liquid cyclones. One is the tangential entry type and the other is the axial entry
type [
5
–
7
]. Axially, the separation is achieved by rotational motion of the fluid through
the blades fixed inside the vessel. Scholars from various countries have conducted a lot of
research on the entry vanes and overall separation performance of this separator, and the
inflow vanes are the core components of the axial gas-liquid separator, and there are more
structural forms, which can be roughly divided into spiral vanes, curved vanes and some
other forms of vanes [8,9].
1.1. Spiral Blade
Currently, spiral vane type gas-liquid separators are more researched and applied.
They are generally used for gas-liquid separation of downhole natural gas. Zhou Guoyan
et al. [
10
,
11
] investigated the effect of pitch and number of spirals on the separation
efficiency of the spiral blades. They compared the indoor test results with the simulation
results and found that the separation efficiency tends to increase and then decrease as the
pitch and number of spirals increase. Moreover, the pressure drop calculation equation of
the separator was fitted based on the Darcy equation using the results simulated for nine
different structural parameters. It was verified that the error was within 20%.
Fu Jing [
12
] investigated the downhole spiral gas-liquid separator for gas wells. She
used Fluent to numerically simulate the downhole gas-liquid separator to optimize the
design of the pitch and number of spiral turns. And she also found that the separator
Processes 2022, 10, 64. https://doi.org/10.3390/pr10010064 https://www.mdpi.com/journal/processes
