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.

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.

Development and Validation of an Ignition Model for SI Engines

2006 ◽  
Author(s):  
Stefania Falfari ◽  
Gian Marco Bianchi
Keyword(s):  
Cfd Simulation ◽  
Combustion Process ◽  
Three Dimensional ◽  
Electrical Energy ◽  
Combustion Model ◽  
Test Case ◽  
Ignition Process ◽  
Mean Flow ◽  
Flame Kernel ◽  
Si Engines

In SI engines the ignition process strongly affects the combustion process. Its accurate modelling becomes a key issue for a design-oriented CFD simulation of the combustion process. Different approaches to simulate ignition have been proposed. The common base is decoupling the physics related to the very first ignition phase when a plasma is formed from that of the development of the flame kernel. The critical point of ignition models is related to the capability of representing the effect of ignition system characteristics, the criterion used for flame deposit and the initialisation of the combustion model. This paper aims to present and validates extensively an ignition model suited for CFD calculation of premixed combustion. The ignition model implemented in a customized version of the Kiva 3 code is coupled with ECFM Flamelet combustion model. The ignition model simulates the plasma/kernel expansion based on a lump evaluation of main ignition processes (i.e., breakdown, arc-phase and glow phase). A double switch criterion based on physical and numerical consideration is used to switch to the main combustion model. The Herweg and Maly experimental test case has been used to check the model capability. In particular, two different ignition systems having different amount of electrical energy released during spark discharge are considered. Comparisons with experimental results allowed testing the model with respect to its capability to reproduce the effects of mixture equivalence ratio, mean flow, turbulence and spark energy on flame kernel development as never done before in three-dimensional RANS CFD combustion modelling of premixed flames.

Effects of combustion temperature on air emissions and support fuel consumption in full scale fluidized bed sludge incineration: with particular focus on nitrogen oxides and total organic carbon

2018 ◽  
Vol 36 (4) ◽  
pp. 342-350
Author(s):  
Margit Löschau
Keyword(s):  
Nitrogen Oxides ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
Combustion Temperature ◽  
Air Pollutant ◽  
Fuel Oil ◽  
Pollutant Emissions ◽  
Oil Consumption ◽  
Incineration Plant ◽  
Sludge Incineration

This article describes a pilot test at a sewage sludge incineration plant and shows its results considering the impacts of reducing the minimum combustion temperature from 850°C to 800°C. The lowering leads to an actual reduction of the average combustion temperature by 25 K and a significant reduction in the fuel oil consumption for support firing. The test shall be used for providing evidence that the changed combustion conditions do not result in higher air pollutant emissions. The analysis focusses on the effects of the combustion temperature on nitrogen oxides (NOx) and total organic carbon emissions. The evaluation of all continuously monitored emissions shows reduced emission levels compared to the previous years, especially for NOx.

scholarly journals The Prototype of Non-thermal Plasma After treatment System for Simultaneous Reduction of Nitrogen Oxide Emission in Flue Gas

2021 ◽  
Vol 302 ◽  
pp. 01010
Author(s):  
Dararat Laohalertdecha ◽  
Kampanart Theinnoi ◽  
Sak Sittichompoo
Keyword(s):  
Nitrogen Oxides ◽  
Nitrogen Oxide ◽  
Flue Gas ◽  
Thermal Plasma ◽  
Power Plants ◽  
Gas Flow ◽  
Nox Reduction ◽  
Combustion Process ◽  
Operating Conditions ◽  
Non Thermal Plasma

Nowadays, global warming is the main environmental problems all over the world. The air pollutants mainly from the burning of fossil fuels and coal in power plants, transportation, and automobiles. There are release major point emission of the atmosphere. The nitrogen oxides are the most relevant for air pollution that contribute to the formation of photochemical smog and acid rain. Numerous methods have been studied to eliminate the nitrogen oxides such as the use low-nitrogen fuels technology, the selective catalytic reduction (SCR), wet scrubbing. The aim of this research is investigated non-thermal plasma (NTP) techniques offer an innovation to eliminate both nitrogen oxide (NOx) and soot emissions from combustion. This study is used to selectively transfer input electrical energy to electrons without expending this in heating the entire gas flow which creates free radicals in the flue gases. The simulated flue gas from combustion process is applied to the system. The results showed that the prototype of nonthermal plasma system is shown the highly efficient of NOx removal was achieved. However, the optimised of NTP operating conditions are required to enhance the NOx reduction activities.

scholarly journals Influence of the Thermal State of Vehicle Combustion Engines on the Results of the National Inventory of Pollutant Emissions

2021 ◽  
Vol 11 (19) ◽  
pp. 9084
Author(s):  
Katarzyna Bebkiewicz ◽  
Zdzisław Chłopek ◽  
Hubert Sar ◽  
Krystian Szczepański ◽  
Magdalena Zimakowska-Laskowska
Keyword(s):  
Carbon Monoxide ◽  
Volatile Organic Compounds ◽  
Nitrogen Oxides ◽  
Organic Compounds ◽  
Thermal State ◽  
Pollutant Emissions ◽  
Pollutant Emission ◽  
Combustion Engines ◽  
Warm Up ◽  
Volatile Organic

The article presents the results of studies on the influence of the thermal state of vehicle combustion engines on pollutant emissions. This influence was analyzed based on data from Poland’s inventory of pollutant emissions for the years 1990–2017. The results show that during engine warm-up, carbon monoxide emission constitutes the largest share (up to 50%) in the national annual total emission. Volatile organic compounds are next in the ranking, whereas the share of nitrogen oxides is the lowest (less than 5%). Under the model traffic conditions, close to those in Poland’s cities in winter, simulation tests regarding additional pollutant emissions from passenger cars during engine warm-up were also carried out. As a result of the cold-start emissive behavior of internal combustion engines, emissions of carbon monoxide and volatile organic compounds showed a considerably greater impact on national pollutant emission, as compared to carbon dioxide, nitrogen oxides and particulate matter. This is particularly evident for the results of the inventory of pollutant emissions from road transport.

KESAN SUDUT PUSARAN TERHADAP PEMBAKARAN MENGGUNAKAN PEMUSAR JEJARIAN DWI ALIRAN

2015 ◽  
Vol 77 (8) ◽  
Author(s):  
Muhammad Roslan Rahim ◽  
Mohammad Nazri Mohd Ja’afar
Keyword(s):  
Swirling Flow ◽  
Combustion Process ◽  
Combustion Efficiency ◽  
Flame Length ◽  
Pollutant Emissions ◽  
Pollutant Emission ◽  
Flame Stability ◽  
Wide Spread ◽  
Blue Colour ◽  
The One

Development of combustion systems which involves retrofitting or design of new burners, is made to reduce the formation of pollutant emissions. The reduction of this pollutant emission results from the complete mixing of fuel and air during the combustion process. Meanwhile, non-complete mixing of fuel and air during combustion process can cause ignition problem and create problems in terms of flame stability and combustion efficiency. This article describes a study on the effects of swirling flow generated by a double radial swirler on flame characteristics that is related to the emission of NO. The double radial swirlers used in this study have the angles of 30°/40°, 30°/50° and 30°/60°. Diesel is used as a fuel in this study. The results show that all double radial swirlers used have different effects on the flame characteristics and temperature profile. From all these double radial swirlers, the one with an angle of 30°/60° produces flame with high temperature, short flame length with blue colour and wide spread.

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.

Benefits of MS 6001B Gas Turbine in Cogeneration: The UEM Power Plant Case

1994 ◽  
Author(s):  
Pierre M. Remy ◽  
Yves M. Bolssenin ◽  
Michel M. Molière
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Steam Injection ◽  
Turn Of The Century ◽  
Fuel Oil ◽  
Pollutant Emissions ◽  
Flexible System ◽  
Major Turning Point ◽  
Heavy Duty Gas Turbine ◽  
The City

Long before the neologism “Cogeneration” was coined (around 1978), UEM’s Chambière Power Plant — which dates back to the turn of the century — was already supplying the city of Metz, east of France, with combined heat and power. In 1992, Chambière experienced a major turning point in its history with the installation of a new unit based on one MS 6001B “Heavy Duty” gas turbine. This model, rated 38 MWe - ISO and burning natural gas or fuel oil has become the core of a new cogeneration unit exhibiting an outstanding performance: - efficiency higher than 80% (LHV) providing a 20% energy saving in comparison to a conventional plant, - low pollutant emissions (NOx, CO, HC) and low contribution to the greenhouse-effect (CO2). The gas turbine has been equipped with two steam injection devices, for DeNOx and power augmentation respectively, resulting in a very flexible system. After describing the power plant and giving its main achievements in the fields of energy and emissions, the paper briefly presents several improvements intended to protect both the turbine and the environment.

scholarly journals Effects of Swirling Strength of the Premixed Gas Flow on Pollutant Emission in a Heavy-Duty Gas Turbine

2019 ◽  
Vol 118 ◽  
pp. 04038
Author(s):  
Huanhuan Gao ◽  
Zaiguo Fu ◽  
Zhuoxiong Zeng ◽  
Jiang Liu ◽  
Peifen Weng
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Gas Flow ◽  
Swirling Flow ◽  
Combustion Process ◽  
Side Wall ◽  
Pollutant Emission ◽  
Heavy Duty ◽  
Average Mass ◽  
Heavy Duty Gas Turbine

The combustion process and pollutant emission of an annular combustion chamber for a heavy-duty gas turbine were investigated by numerical method. The realizable k-ε model and finite rate/eddy dissipation model were adopted for calculations of turbulence and combustion. The effects of different swirling numbers of the double-swirler inlet on the temperature distribution and the thermal NOx formation in the combustion chamber were analyzed. The results show that the change of the swirling number of the outer swirling flow has a greater influence on the generation of the thermal NOx when compared with that of the inner swirling flow. The maximum average temperature of the central cross section of the combustor does not exceed 1760K. The average mass fraction of the generated thermal NOx at the exit decreases with the increasing outer swirling number. When the outer swirling number is less than 0.8, the generation of the thermal NOx is severe at the side wall of the combustion chamber.

scholarly journals Influence of Molding Technology on Thermal Efficiencies and Pollutant Emissions from Household Solid Fuel Combustion during Cooking Activities in Chinese Rural Areas

Symmetry ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2223
Author(s):  
Juan Qi ◽  
Jianjun Wu ◽  
Lei Zhang
Keyword(s):  
Wheat Straw ◽  
Rice Straw ◽  
Solid Fuel ◽  
Combustion Process ◽  
Pollutant Emissions ◽  
Pollutant Emission ◽  
Molding Pressure ◽  
Process Conditions ◽  
Ignition Point ◽  
Maize Straw

Resident combustion of solid fuel has been widely acknowledged as a high potential for pollutant reduction. However, there is a marked asymmetry between more pollutant emission and less burned volatiles of biomass and coal in the combustion process. To study the solid fuel optimum combustion form in a household stove, both the pollution reduction and energy efficient utilization of crop straws and coals were investigated. Taking the molding pressure and clay addition ratio as variable process conditions, the research of bio-coal briquette (made from the mixture of anthracite and biomass) was implemented in the range of 15~35 MP and 5~15%, respectively. Biomass and coal work complementarily for each other’s combustion property development. In particular, the pyrolysis gas produced by biomass low-temperature devolatilization is featured with low ignition point and is distributed in the bio-coal briquette. Its own combustion provides energy for anthracite particle combustion. Consequently, a positive effect was identified when bio-coal briquettes were used as residential fuel, and further improvement manifested in reducing more than 90% of particle matter (PM) and achieving about twice the thermal efficiencies (TEs) compared with the mass-weighted average values of coal briquettes and biomass briquettes. 88.8 ± 11.8%, 136.7 ± 13.7% and 81.4 ± 17.7% more TEs were provided by wheat straw–coal briquettes, rice straw–coal briquettes and maize straw–coal briquettes. 93.3 ± 3.1% (wheat straw–coal), 97.6 ± 0.2% (rice straw–coal) and 90.4 ± 2.2% (maize straw–coal) in terms of PM2.5 emission factors (EFs) was reduced. For bio-coal briquette, a 25 MPa and 10% addition were determined as the optimum molding pressure and clay addition ratio. Bio-coal briquettes with higher TEs and lower PM EFs will bring about substantial benefits for air quality promotion, human health and energy saving.

Sign in / Sign up

Export Citation Format

Share Document