Reduction in Pollutants Emissions From Domestic Boilers—Computational Fluid Dynamics Study

This study is concerned with building a computational fluid dynamics (CFD) model to simulate the combustion process occurring in the combustion chamber of some domestic boilers. The burner used in this boiler is a conventional cylindrical premix burner with small inlet holes on its surface. A two-dimensional CFD model is built to simulate the combustion chamber domain, and the partially premixed combustion model with a postprocessor for NOx calculations is used to simulate the combustion process inside the combustion chamber. A complete description of the formation characteristics of NOx produced from the boiler is discussed in detail. A comparison between the CFD numerical results and the experimental measurements at different boiler loads is performed in order to validate the numerical model and investigate the accuracy of the CFD model. The validated CFD model is used to investigate the effect of different boundaries temperatures and the mixture inlet velocity on the flue gas average temperature, residence time, and hence the CO and NOx concentrations produced from the combustion chamber. The concept of changing the mixture inlet velocity is found to be an effective method to improve the design of the burner in order to reduce the pollutant emissions produced from the boiler with no effect on the boiler efficiency.

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Reduction of Pollutants Emissions From Domestic Boilers: CFD Study

Volume 3: Combustion Science and Engineering ◽

10.1115/imece2008-68780 ◽

2008 ◽

Author(s):

Gasser Hassan ◽

Mohamed Pourkashanian ◽

Derek Ingham ◽

Lin Ma ◽

Stephen Taylor

Keyword(s):

Combustion Chamber ◽

Combustion Process ◽

Pollutant Emissions ◽

Combustion Model ◽

Cfd Model ◽

Inlet Velocity ◽

Average Temperature ◽

Partially Premixed Combustion ◽

Boiler Efficiency ◽

Computational Fluid Dynamics Cfd

This study is concerned with building a computational fluid dynamics (CFD) model to simulate the combustion process occurring in the combustion chamber of some domestic boilers. The burner used in this boiler is a conventional cylindrical premix burner with small inlet holes on its surface. A two-dimensional (2D) CFD model is built to simulate the combustion chamber domain and the partially premixed combustion model with a postprocessor for NOx calculations is used to simulate the combustion process inside the combustion chamber. A complete description of the formation characteristics of NOx produced from the boiler is discussed in detail. A comparison between the CFD numerical results and the experimental measurements at different boiler loads is performed in order to validate the numerical model and investigate the accuracy of the CFD model. The validated CFD model is used to investigate the effect of different boundaries temperatures and the mixture inlet velocity on the flue gas average temperature, residence time and hence the CO and NOx concentrations produced from the combustion chamber. The concept of changing the mixture inlet velocity is found to be an effective method to improve the design of the burner in order to reduce the pollutant emissions produced from the boiler with no effect on the boiler efficiency.

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Simulation of Combustion Process in Diesel Engines Based on Eddy Dissipation Model

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.823.315 ◽

2016 ◽

Vol 823 ◽

pp. 315-318

Author(s):

Mahran Dawwa

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Combustion Chamber ◽

Diesel Engines ◽

Combustion Process ◽

Premixed Combustion ◽

Dissipation Model ◽

Simulation Results ◽

Dynamics Method

The aim of this study is to simulate the combustion process in the combustion chamber of diesel engines by using eddy dissipation model (EDM) and computational fluid dynamics method (CFD). Computational fluid dynamics has been used wieldy in the recent years for simulating the strokes of diesel engines including the combustion process. Eddy dissipation model can be used for simulating non-premixed combustion cases such as the combustion in diesel engines. The simulation steps and the simulation results will be discussed and illustrated. ANSYS program is the software which used for performing this simulation.

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Study of Combustion Instabilities Imposed by Inlet Velocity Disturbance in Combustor Using LES

Volume 2: Combustion, Fuels and Emissions ◽

10.1115/gt2009-59132 ◽

2009 ◽

Author(s):

Kenji Sato ◽

Ed Knudsen ◽

Heinz Pitsch

Keyword(s):

Transfer Function ◽

Flow Field ◽

Heat Release ◽

Combustion Chamber ◽

Combustion Process ◽

Variable Density ◽

Combustion Model ◽

Combustion Instabilities ◽

Inlet Velocity ◽

Good Agreement

Stable combustion is one of the most important requirements for the development of heavy duty gas turbine engines that comply with stringent environmental regulations at high firing temperatures. In this research, one of the typical combustion instabilities which is caused by an acoustically forced velocity disturbance is investigated using variable density LES simulations. The G-equation approach for LES is used as the combustion model [1], and an experiment by Balachandran et al. [2, 3] is selected for case study. The velocity profiles in the experimental combustion chamber are compared with experimentally measured data at non-reacting conditions and it is confirmed that these are in good agreement. At the reacting conditions, predicted flame shapes are compared with OH PLIF measurements. The transfer function of the heat release due to inlet velocity forcing at 40 Hz and 160 Hz frequencies is also compared with the experimental data. These are in good agreement, including the nonlinear response of heat release. The transfer function is highly related to the flow field. The non-linearity of the transfer function can be traced to the interaction of the flow field in the combustion chamber with the combustion process itself.

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STUDI PERBANDINGAN SIMULASI PROSES PEMBAKARAN BATUBARA DAN VINASSE METODE NON-PREMIX COMBUSTION MODEL

Konversi ◽

10.20527/k.v4i1.262 ◽

2015 ◽

Vol 4 (1) ◽

pp. 25

Author(s):

Bayu Triwibowo ◽

Abdul Halim ◽

Annie Mufyda Rahmatika

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Combustion Process ◽

Two Dimensions ◽

Combustion Characteristic ◽

Combustion Model ◽

Premix Combustion ◽

Computational Fluid Dynamics Cfd ◽

Dynamics Method

Abstrak-Vinasse merupakan limbah dari industri gula dengan debit yang sangat besar sehingga harus diolah dengan berbagai metode. Salah satu alternatif metode yang dapat digunakan adalah pembakaran. Pembakaran merupakan reaksi kimia yang memproduksi panas dan dapat digunakan sebagai suplai energi untuk proses selanjutnya. Berdasarkan analisis proksimat dan ultimat, vinasse memiliki karakteristik yang hampir sama dengan batubara setelah mengalami proses evaporasi. Penelitian ini mempelajari perbandingan dari karakteristik pembakaran antara batubara dan vinasse sebagai bahan bakar yang dilihat dari aspek distribusi temperatur, distribusi spesies, dan vektor kecepatan. Proses pembakaran dijalankan dengan metode computational fluid dynamics (CFD) khususnya model pembakaran non-premix. Geometri dari ruang bakar yang digunakan adalah 84 x 5,2 m dengan kualitas ortogonal mesh yang digunakan mendekati 1 dan bentuk cell segiempat 100 persen. Simulasi pembakaran dijalankan dengan geometri 2D (dua dimensi) dengan udara sebagai oksidator. Hasil dari simulasi menunjukkan bahwa vinasse memiliki potensi untuk digunakan sebagai bahan bakar alternatif karena lebih cepat terbakar dibandingkan dengan batubara serta karakteristik lain yang sedikit berbeda. Kata kunci : pembakaran, vinasse, batubara, CFD, non-premix Abstract-Vinasse as a sugarcane waste has large amount of debit that must be treated through various methods. One of the methods is combustion. Combustion is a chemical reaction that produced heat which is can be used as energy supply for further process. Vinasse according to proxymate and ultimate analysis has characteristic similar to coal after being evaporated. This paper is studied about the comparassion of combustion characteristic between vinasse and coal as a fuel in terms of temperature distribution, species distribution, and velocity vector. Combustion process conducted with computational fluid dynamics method especially non-premix combustion model. The geometry of furnace is 84 m x 5.2 m with the orthogonal quality of mesh is close to 1 and 100 percent of quad cells. The simulation of combustion process conducted in 2D (two dimensions) with air as oxydizer. The results of the simulation shows that vinasse were very potential to use as a fuel with quicker combustion compared to coal but with slightly different characteristic. Keywords : Combustion, vinasse, coal, CFD, non-premix

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The Study of Waste-to-Energy Plant Combustion Characteristics Based on Computational Fluid Dynamics

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.871.259 ◽

2013 ◽

Vol 871 ◽

pp. 259-262

Author(s):

Gui Chuan Hu

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Mass Fraction ◽

Combustion Process ◽

Waste To Energy ◽

Pollutant Emissions ◽

Plant Design ◽

Detailed Understanding ◽

Energy Plant ◽

Proximate And Ultimate Analyses

The combustion process for using municipal solid waste as a fuel within a waste to energy plant calls for a detailed understanding of the following phenomena. Firstly, this process depends on many input parameters such as proximate and ultimate analyses, the season of the year, primary and secondary inlet air velocities and, secondly, on output parameters such as the temperatures or mass fraction of the combustible products. The variability and mutual dependence of these parameters can be difficult to manage in practice. Another problem is how these parameters can be tuned to achieving optimal combustible conditions with minimal pollutant emissions, during the plant-design phase. In order to meet these goals, a waste-to-energy plant with bed combustion was investigated by using computational fluid-dynamics approach.

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

Energies ◽

10.3390/en12061036 ◽

2019 ◽

Vol 12 (6) ◽

pp. 1036 ◽

Cited By ~ 4

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.

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Design of Road-Side Barriers to Mitigate Air Pollution near Roads

Applied Sciences ◽

10.3390/app11052391 ◽

2021 ◽

Vol 11 (5) ◽

pp. 2391

Author(s):

Jose I. Huertas ◽

Javier E. Aguirre ◽

Omar D. Lopez Mejia ◽

Cristian H. Lopez

Keyword(s):

Fluid Dynamics ◽

Air Pollution ◽

Computational Fluid Dynamics ◽

Sulfur Hexafluoride ◽

Computational Domain ◽

Cfd Model ◽

Near Surface ◽

The Road ◽

Pollutant Concentrations ◽

Highly Correlated

The effects of using solid barriers on the dispersion of air pollutants emitted from the traffic of vehicles on roads located over flat areas were quantified, aiming to identify the geometry that maximizes the mitigation effect of air pollution near the road at the lowest barrier cost. Toward that end, a near road Computational Fluid Dynamics (NR-CFD) model that simulates the dispersion phenomena occurring in the near-surface atmosphere (<250 m high) in a small computational domain (<1 km long), via Computational Fluid Dynamics (CFD) was used. Results from the NR-CFD model were highly correlated (R2 > 0.96) with the sulfur hexafluoride (SF6) concentrations measured by the US-National Oceanic and Atmospheric Administration (US-NOAA) in 2008 downwind a line source emission, for the case of a 6m near road solid straight barrier and for the case without any barrier. Then, the effects of different geometries, sizes, and locations were considered. Results showed that, under all barrier configurations, the normalized pollutant concentrations downwind the barrier are highly correlated (R2 > 0.86) to the concentrations observed without barrier. The best cost-effective configuration was observed with a quarter-ellipse barrier geometry with a height equivalent to 15% of the road width and located at the road edge, where the pollutant concentrations were 76% lower than the ones observed without any barrier.

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