skip to Main Content

usa+1 (903) 231-3943 ge+995 (593) 675-107

Sale

Gasification CFD Simulation in a Gasifier Chamber

$78.00 $50.00

Rated 0 out of 5
(be the first to review)

The present problem simulates the gasification process inside a gasifier chamber.

 

This ANSYS Fluent project includes CFD simulation files and a training movie.

There are some free products to check the service quality.

To order your ANSYS Fluent project (CFD simulation and training), contact our experts via info@mr-cfd.com, online support, and WhatsApp.

Description

Gasification Project Description

The present problem simulates the gasification process inside a gasifier chamber. The gasification process is a set of chemical reactions in which a carbon-based substance is converted to carbon monoxide, hydrogen, and carbon dioxide. The product of this process is considered as a renewable energy source that has many applications in industry.

In this case, a material is defined as fuel, with a density of 1550 kg.m-3 and a specific heat capacity of 1680 j.kg-1.K-1, which is sprayed into the chamber and reacts with water vapor at high temperature. Water vapor is also created by the process of evaporation of water droplets inside the chamber. Therefore, to simulate this model, it is necessary to define discrete phases within the continuous phase.

Hence, the discrete phase model (DPM) is used along with the injection process for this model. The fuel stream enters the gasifier chamber from the lower area in the form of stagnant particles with a velocity of 30 m.s-1, a temperature of 393.15 K, and mass flow rate of 0.2 kg.s-1; While the flow of liquid water in the form of droplets with a velocity of 122 ms-1, temperature 673.15 K and a flow rate of 0.02 kg.s-1 enters the chamber from the middle area and under the process of evaporation turns into water vapor to react with fuel particles.

The entry of these two flow into the chamber leads to a reaction between them. To strengthen and accelerate the reaction process between them, two conical areas have been used on both sides of these input flows. Also, each input flow enters the chamber from two pipes in opposite directions to each other and at an angle of 180 degrees to each other, both of which lead to a vortex flow and thus strengthen the mixing of the two flows.

Also in the present simulation it is necessary to define the chemical reactions between the input flows and the production of the desired gaseous species. Therefore, for the mentioned modeling, the model of species transport with volumetric reactions has been used and to define the type of reactants and the process of chemical reactions, the CHEMKIN mechanism has been used, which includes 5 chemical reactions involving 8 different types of reactants and products.

The reactions related to this reaction pattern are presented in the table below. This model also assumes that radiation heat transfer due to chemical reactions occurs inside the gasifier chamber, and hence, the P1 model is defined for simulation.

gasification

Gasifier Geometry & Mesh

The present 3-D model is designed using Design Modeler software. The geometry of the model consists of a two-piece cylindrical chamber 7.5 m long and 0.8 m in diameter; So that the upper part has a length equal to 5 m and the lower part has a length equal to 2.5 m. The lower part consists of two cones on either side of it in opposite directions;

So that the cone in the middle of the chamber has a diameter of 0.6 m and a height of 0.3 m, and the cone at the bottom of the chamber has a diameter of 0.8 m and a height of 0.35 m. There are two pipes for fuel inlet in the lower part of the chamber, in the form of a narrow cylinder with a diameter of 0.1 m but in opposite directions to each other and at an angle of 180 degrees.

The two pipes for liquid water inlet are located in the middle of the chamber, in the form of a narrow cylinder with a diameter of 0.05 m but in opposite directions to each other and at an angle of 180 degrees. The product outlet pipe with a diameter of 0.2 m is placed at the top of the chamber. The figure below shows a view of the geometry.

gasification

The meshing of the model has been done using ANSYS Meshing software and the mesh type is unstructured. The element number is 219170. The following figure shows the mesh.

gasification

Gasification CFD Simulation

To simulate the present model, several assumptions are considered:

  • We perform a pressure-based solver.
  • The simulation is steady.
  • The gravity effect on the fluid is ignored.

A summary of the defining steps of the problem and its solution is given in the following table:

Models (Gasification)
Viscousk-epsilon
k-epsilon modelstandard
near-wall treatmentstandard wall function
Radiation modelP1
Species modelSpecies transport
reactionsvolumetric
mixture speciesO2, N2, CH4, H2, CO2, H2O, air
Discrete phase modelOn
Injectionactive
Injection

1 & 2

anthracite

particle typeInert
injection typesurface
point propertiestemperature393.15 K
velocity magnitude30 m.s-1
diameter0.000001 m
total flow rate0.2 kg.s-1
Injection

3 & 4

water-liquid

particle typedroplet
injection typesurface
point propertiestemperature673.15 K
velocity magnitude122 m.s-1
diameter0.000001 m
total flow rate0.02 kg.s-1
EnergyOn
Boundary conditions (Gasification)
Inlet-1 & Inlet 2Velocity inlet
velocity magnitude30 m.s-1
temperature393.15 K
internal emissivity1
all species mass fractions0
discrete phase BC typeescape
Inlet-3 (up – down) &

Inlet 4 (up – down)

Velocity inlet
velocity magnitude122 m.s-1
temperature673.15 K
internal emissivity1
all species mass fractions0
discrete phase BC typeescape
Wall-up

&

Wall-down

Wall
wall motionstationary wall
heat flux0 W.m-2
internal emissivity1
all species boundary conditionszero diffusive flux
discrete phase model conditionsreflect
OutletPressure outlet
gauge pressure0 Pascal
internal emissivity1
discrete phase BC typeescape
Methods (Gasification)
Pressure-velocity couplingSIMPLE
pressuresecond order
momentumsecond order upwind
turbulent kinetic energyfirst order upwind
turbulent dissipation ratefirst order upwind
H2O – O2 – N2 – CH4 – CO – H2 – CO2second order upwind
energysecond order upwind
Initialization (Gasification)
Initialization methodsStandard
velocity (x,y,z)0 m.s-1
temperature400 K
gauge pressure0 Pascal
H2O0.3
O2 – N2 – CH4 – CO – H2 – CO20

Results

At the end of the solution process, three-dimensional temperature and velocity counters, three-dimensional velocity vectors, and a particle track are obtained.

 

All files, including Geometry, Mesh, Case & Data, are available in Simulation File. By the way, Training File presents how to solve the problem and extract all desired results.

Reviews

There are no reviews yet.

Leave a customer review

Your email address will not be published. Required fields are marked *

Back To Top
×Close search
Search
Call On WhatsApp