Combustion Modelling of a 20 kW Pellet Boiler

2018 ◽  
Author(s):  
João Silva ◽  
Lelis Fraga ◽  
Manuel Eduardo Ferreira ◽  
Sergio Chapela ◽  
Jacobo Porteiro ◽  
...  
Keyword(s):  
Cfd Simulation ◽  
Combustion Process ◽  
Packed Bed ◽  
Pollutant Emissions ◽  
Cfd Modeling ◽  
Ansys Fluent ◽  
Fully Integrated ◽  
Complex Process ◽  
Combustion Modelling ◽  
Physical And Chemical

In a domestic boiler that uses pellets as fuel, it is important to control the efficiency of the combustion process. The combustion process in the boiler is a complex process that involves several and simultaneous phenomena such as fluid flow, physical and chemical reactions and heat and mass transfer. Computational Fluid Dynamics (CFD) modeling in combination with detailed sub-models for the solid fuel conversion is a useful tool to study the combustion performance and to study, for instance, the pollutant emissions. This paper presents the CFD simulation of the combustion in a 20 kW pellet boiler using the ANSYS Fluent software with a fully integrated packed-bed model. Furthermore, an experimental test was performed to contrast the results obtained. The CFD results were able to predict the arrangement of the particles on the grate, temperature profile of the particles and, the main gas species concentration inside of the boiler with reasonable accuracy when compared with the experimental measurements.

scholarly journals POSSIBILITIES TO REDUCE POLLUTANT EMISSIONS IN NAVAL DIESEL ENGINES

2020 ◽  
Vol 10 (3) ◽  
pp. 5-9
Author(s):  
Mihail Lucian DUMITRACHE ◽  
Catalin FAITAR
Keyword(s):  
Mathematical Models ◽  
Computer Technology ◽  
Combustion Process ◽  
Difficult Problem ◽  
Production Costs ◽  
Pollutant Emissions ◽  
Mixture Formation ◽  
Complex Process ◽  
Emission Estimation ◽  
Over Time

The combustion process is, by far, the most important and complex process that takes place in engines. Its importance is given by the fact that it provides the flow of energy used in the engine and is the source of all pollutant emissions, the efficiency of the engine being directly influenced by it. The mechanisms of combustion are particularly complex and are not fully known even today, the most difficult problem being the mechanisms of mixture formation and the chemistry of the combustion process. Over time, depending on the evolution of knowledge in the field and computer technology, various mathematical models have been developed, which have. Emission estimation and theoretical verification, in the first phase, of the solutions applicable to in-service enginescould greatly reduce research and production costs, given that there are a variety of engines onboard ships and measurements in operation are very difficult.

scholarly journals Design improvement of an airbox for a passenger vehicle

2021 ◽  
Vol 2120 (1) ◽  
pp. 012010
Author(s):  
J Tan ◽  
N Z Abu Bakar
Keyword(s):  
Numerical Simulation ◽  
Pressure Drop ◽  
Simulation Model ◽  
Cfd Simulation ◽  
Pollutant Emissions ◽  
Passenger Vehicle ◽  
Repeated Testing ◽  
Road Transportation ◽  
Ansys Fluent ◽  
Testing Cost

Abstract The purpose of an airbox is to provide the engine with a clean air flow for combustion. The high velocity of the fluid flow across the airbox will create a pressure drop resulting a decline in the vehicle’s performance. This project collaborates with an Original Equipment Manufacturer (OEM) to develop a numerical simulation model for a new airbox design and to compare its pressure drop with OEM production design. Reducing the pressure drop across the airbox can increase the efficiency of a vehicle, hence, reducing CO2 emissions. This research focuses on the passenger type vehicle as it is the highest source of carbon dioxide (CO2) being emitted for road transportation and these pollutant emissions have also caused many health problems on human. ANSYS Fluent program was used to carry out Computational Fluid Dynamics (CFD) simulation for both OEM and the new design. Then, the same simulation setup was used for the new design. The inlet size of the new design is larger when compared to the OEM design. After analysing both models, it was determined that the main reason behind the pressure loss was caused by the shape of the airbox and turbulent flow inside. The new airbox design shows reduction of 96% in the pressure drop within it and in return, enhancing the performance of the passenger vehicle. This conclude that numerical simulation model is able to provide a good indicator for the designer to choose the best design and proceed with fabrication and conduct actual test, thus saving a lot of prototyping and repeated testing cost.

CFD Simulation of a Microturbine Annular Combustion Chamber Fuelled With Methane and Biomass Pyrolysis Syngas: Preliminary Results

2009 ◽  
Author(s):  
Francesco Fantozzi ◽  
Paolo Laranci ◽  
Michele Bianchi ◽  
Andrea De Pascale ◽  
Michele Pinelli ◽  
...  
Keyword(s):  
Experimental Data ◽  
Natural Gas ◽  
Combustion Chamber ◽  
Gas Turbines ◽  
Cfd Simulation ◽  
Combustion Process ◽  
Calorific Value ◽  
Methane Combustion ◽  
Pollutant Emissions ◽  
Preliminary Results

Micro gas turbines could be profitably used, for distributed energy production, also exploiting low calorific value biomass-derived fuels, obtained by means of integrated pyrolysis and/or gasification processes. These synthesis gases show significant differences with respect to natural gas (in terms of composition, low calorific value, hydrogen content, tar and particulate matter content) that may turn into ignition problems, combustion instabilities, difficulties in emission control and fouling. CFD simulation of the combustion chamber is a key instrument to identify main criticalities arising when using these gases, in order to modify existing geometries and to develop new generation combustion chambers for use with low calorific value gases. This paper describes the numerical activity carried out to analyze the combustion process occurring inside an existing microturbine annular combustor. A CFD study of the combustion process performed with different computational codes is introduced and some preliminary results are reported in the paper. A comparison of results obtained with the different codes is provided, for the reference case of methane combustion. A first evaluation of the pollutant emissions and a comparison with the available experimental data is also provided in the paper, showing in particular a good matching of experimental data on NOx emissions at different load conditions. Moreover, the carried out investigation concerns the case of operation with a syngas fuel derived from pyrolysis of biomass and finally the case of syngas and natural gas co-firing. This combustion condition is simulated with a simple reduced chemical kinetic scheme, in order to assess only the key issues rising with this fuel in comparison with the case of methane combustion. The analysis shows that in case of syngas operation the combustor internal temperature hot spots are reduced and the primary zone flame tends to stabilize closer to the injector, with possible implications on the emission release.

CFD Modeling of Flame Structures in a Gas Turbine Combustion Reactor: Velocity, Temperature, and Species Distribution

2017 ◽  
Vol 15 (4) ◽  
Author(s):  
Alireza Bahramian ◽  
Mozhdeh Maleki ◽  
Bijan Medi
Keyword(s):  
Temperature Profile ◽  
Gas Turbine ◽  
Cfd Simulation ◽  
Flame Structure ◽  
Combustion Process ◽  
Three Dimensional ◽  
Species Distributions ◽  
Kinetic Mechanism ◽  
Cfd Modeling ◽  
Laser Measurements

Abstract This paper presents the computational fluid dynamics (CFD) simulation of a gas turbine combustor with methane-air fuel at atmospheric pressure. The velocity fields, temperature profile and species distributions have been numerically studied. The mathematical combustion models, namely Eddy Dissipation Concept (EDC) model coupled with detailed kinetic mechanism, and Finite Rate/Eddy Dissipation (FR-ED) model coupled with a simple global kinetic mechanism, have been used in numerical analysis considering a two-step oxy-combustion reaction kinetics model. Moreover, a series of CFD results with consideration of EDC model have been obtained by two- and three-dimensional simulations. An error analysis showed that the 3-D simulation with EDC model can accurately predict the velocity components, temperature profile, and species distributions of the combustion process and allow detailed investigation of the flame structure. The CFD results are in agreement with the experimental data obtained from laser measurements.

CFD Simulation of Confined Non-Premixed Flames

2012 ◽  
Author(s):  
Tanaji M. Dabade ◽  
Xianchang Li ◽  
Daniel Chen ◽  
Helen Lou ◽  
Christopher Martin ◽  
...  
Keyword(s):  
Cfd Simulation ◽  
Flame Structure ◽  
Combustion Process ◽  
Premixed Combustion ◽  
Flame Height ◽  
Combustion Model ◽  
Ansys Fluent ◽  
Innovative Strategies ◽  
Precise Control ◽  
Fuel Jet

Material processing furnaces are the key component of the manufacturing industries. The burners used in these furnaces require precise control over the flame structure such as flame shape, height, and width. This study mainly focused on the simulation of the flame structure with Computational Fluid Dynamics (CFD) approach. ANSYS Fluent 13.0 was used to predict the flame characteristics in an enclosed cylinder. Non-premixed combustion model was applied to this combustion phenomenon. To control the flame structure, a micro jet at the centre of the burner is introduced. The effect on flame parameters with varying flow rates of micro jet, fuel jet and co-flow jet is examined. This study confirms the experimental study by Sinha et al. [1], which concluded that an air micro jet at the center of a non-premixed flame can control the flame height and luminosity. Moreover, this paper visualizes the thermo chemistry and transport phenomenon of non-premixed combustion process. Emissions from the combustion are monitored for different boundary conditions. This study shows that innovative strategies can be developed for the precise control over the different types of flames with the help of numerical modeling.

scholarly journals Computational Fluid Dynamics-Based Efficiency Evaluation of Ammonia Containing Gas Combustion in the Claus Reaction Furnaces

2021 ◽  
Vol 134 (3) ◽  
pp. 29-34
Author(s):  
I. R. Karimov ◽  
◽  
А. V. Klinov ◽  
L. R. Minibaeva ◽  
◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Cfd Simulation ◽  
Combustion Process ◽  
Acid Gases ◽  
Ansys Fluent ◽  
Gas Combustion ◽  
Actual Performance ◽  
Recovery Unit ◽  
Sulphur Recovery

Based on the computational fluid dynamics method using ANSYS Fluent software, we carried out a simulation of acid gases combustion process in the Claus furnaces with further combustion of ammonia containing gas originated from sour water stripper. The sulphur recovery unit of the heavy residue conversion complex owned by TAIF-NK was considered as a research subject. As per the results of CFD-simulation, the optional scenarios were defined for utilization of ammonia containing acid gases in the sulphur recovery unit by adjustment of gas composition, thermodynamic conditions, as well as by controlling the flow pattern in the Furnace. The data obtained agree quite well with the actual performance parameters of the existing unit and the findings in the public domain.

CFD Simulation of Pollutant Emission in Power Plant Boilers

2011 ◽  
Author(s):  
Iva´n F. Galindo-Garci´a ◽  
Ana K. Va´zquez-Barraga´n ◽  
Alejandro G. Mani´-Gonza´lez ◽  
Miguel Rossano-Roma´n
Keyword(s):  
Power Plant ◽  
Nitrogen Oxides ◽  
Gas Flow ◽  
Cfd Simulation ◽  
Combustion Process ◽  
Fuel Oil ◽  
Pollutant Emissions ◽  
Pollutant Emission ◽  
Mean Flow ◽  
Flow Equations

A computational model is developed in order to investigate pollutant emissions from power plant boilers to the atmosphere. A well-known method of pollutant reduction is the modification of the combustion conditions to prevent their formation, and 3D computational fluid dynamics (CFD) codes provide an effective tool for the analysis of the combustion process. In this paper CFD calculations were performed to analyze the effect of the amount of combustion air on the production and emission of nitrogen oxides, one of the main pollutants produced during the combustion process. For this analysis the appropriate modeling of the chemical and physical phenomena involved is important, because the production and transport of pollutant species strongly depend on the flow and temperature distributions in the furnace. Two case studies are presented: a pulverized coal-firing tangential boiler and a fuel-oil frontal boiler. The CFD calculations adopt a 3D-formulation of the mean flow equations in combination with the standard high-Reynolds-number k-ε turbulence model. The model domain consists of the whole boiler, from the burner nozzles up to the exit of the economizer. Due to their complex geometrical features and computational limitations bank tubes are not modeled individually, but are grouped in a total volume. A porous media region approach is then undertaken to model gas flow and heat transfer in each heat exchanger. Model validation is a difficult task due to the lack of available data from commercial utilities. Validation has been done using routinely measured global parameters. Relatively good agreement is obtained. Results show that increasing the amount of air reduce nitrogen oxides formation for the case of the tangential boiler, however for the frontal boiler case this behavior is not as evident. These results demonstrate that CFD simulations are a viable tool to study the effect some combustion parameters have on the production of pollutants. CFD results may help to establish trends that, in turn, may help to reduce pollutant emissions from power plant boilers.

Experimental and Numerical Analysis of a Motorcycle Air Intake System Aerodynamics and Performance

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
M. A. Abd Halim ◽  
N. A. R. Nik Mohd ◽  
M. N. Mohd Nasir ◽  
M. N. Dahalan
Keyword(s):  
Combustion Process ◽  
Three Dimensional ◽  
Engine Performance ◽  
Internal Flow ◽  
Rapid Expansion ◽  
Navier Stokes ◽  
Turbulent Fluctuation ◽  
Ansys Fluent ◽  
Induction System ◽  
Acceleration And Deceleration

Induction system or also known as the breathing system is a sub-component of the internal combustion system that supplies clean air for the combustion process. A good design of the induction system would be able to supply the air with adequate pressure, temperature and density for the combustion process to optimizing the engine performance. The induction system has an internal flow problem with a geometry that has rapid expansion or diverging and converging sections that may lead to sudden acceleration and deceleration of flow, flow separation and cause excessive turbulent fluctuation in the system. The aerodynamic performance of these induction systems influences the pressure drop effect and thus the engine performance. Therefore, in this work, the aerodynamics of motorcycle induction systems is to be investigated for a range of Cubic Feet per Minute (CFM). A three-dimensional simulation of the flow inside a generic 4-stroke motorcycle airbox were done using Reynolds-Averaged Navier Stokes (RANS) Computational Fluid Dynamics (CFD) solver in ANSYS Fluent version 11. The simulation results are validated by an experimental study performed using a flow bench. The study shows that the difference of the validation is 1.54% in average at the total pressure outlet. A potential improvement to the system have been observed and can be done to suit motorsports applications.

scholarly journals Combustion Optimization for Coal Fired Power Plant Boilers Based on Improved Distributed ELM and Distributed PSO

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1036 ◽  
Author(s):  
Xinying Xu ◽  
Qi Chen ◽  
Mifeng Ren ◽  
Lan Cheng ◽  
Jun Xie
Keyword(s):  
Power Plant ◽  
Combustion Process ◽  
Optimization Method ◽  
Combustion Efficiency ◽  
Pollutant Emissions ◽  
Combustion Model ◽  
Nox Emissions ◽  
Coupling Characteristics ◽  
Learning Machine ◽  
Combustion Optimization

Increasing the combustion efficiency of power plant boilers and reducing pollutant emissions are important for energy conservation and environmental protection. The power plant boiler combustion process is a complex multi-input/multi-output system, with a high degree of nonlinearity and strong coupling characteristics. It is necessary to optimize the boiler combustion model by means of artificial intelligence methods. However, the traditional intelligent algorithms cannot deal effectively with the massive and high dimensional power station data. In this paper, a distributed combustion optimization method for boilers is proposed. The MapReduce programming framework is used to parallelize the proposed algorithm model and improve its ability to deal with big data. An improved distributed extreme learning machine is used to establish the combustion system model aiming at boiler combustion efficiency and NOx emission. The distributed particle swarm optimization algorithm based on MapReduce is used to optimize the input parameters of boiler combustion model, and weighted coefficient method is used to solve the multi-objective optimization problem (boiler combustion efficiency and NOx emissions). According to the experimental analysis, the results show that the method can optimize the boiler combustion efficiency and NOx emissions by combining different weight coefficients as needed.

scholarly journals Performance Study of Grass-Derived Nano-Cellulose and Polycaprolactone Composites for 3D Printing

2021 ◽  
Vol 11 (3) ◽  
pp. 1273
Author(s):  
Chen Feng ◽  
Jiping Zhou ◽  
Xiaodong Xu ◽  
Yani Jiang ◽  
Hongcan Shi ◽  
...  
Keyword(s):  
3D Printing ◽  
Mechanical Test ◽  
Chemical Properties ◽  
Test Results ◽  
Performance Study ◽  
Compression Process ◽  
Ansys Fluent ◽  
Nano Cellulose ◽  
Physical And Chemical ◽  
And Chemical Properties

In recent years, 3D printing has received increasing attention from researchers. This technology overcomes the limitations of traditional technologies by printing precise and personalized scaffold with arbitrary shapes, pore structures, and porosities for the applications in various tissues. The cellulose nanocrystal (CNC) is extracted from Humulus Japonicus (HJS) and mixed with poly(ε-caprolactone) (PCL) to prepare a series of CNC/PCL composites for printing. Based on the analysis of the physical and chemical properties of the series of the CNC/PCL composites, an optimal mass ratio of CNC to PCL was obtained. The Solidworks was used to simulate the stretching and compression process of the scaffolds with three different patterns under an external force. The flow of nutrient solution in the scaffolds with different patterns was simulated by ANSYS FLUENT, and then a new optimization scaffold pattern with a concave hexagon shape was advised based on the simulation results. Collectively, the mechanical test results of the material and scaffold confirmed that the optimal filling amount of the CNC was 5%, and the scaffold pattern with concave hexagon shape exhibited better mechanical properties and suitable for the transport of cells and nutrients, which is expected to be more widely used in 3D printing.

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