Co-combustion of anthracite coal and wood pellets: Thermodynamic analysis, combustion efficiency, pollutant emissions and ash slagging

2018 ◽  
Vol 239 ◽  
pp. 21-29 ◽  
Author(s):  
Feihong Guo ◽  
Zhaoping Zhong
Keyword(s):  
Thermodynamic Analysis ◽  
Combustion Efficiency ◽  
Pollutant Emissions ◽  
Wood Pellets ◽  
Anthracite Coal

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.

Effect of Air Distribution on Solid Fuel Bed Combustion

1997 ◽  
Vol 119 (2) ◽  
pp. 120-128 ◽  
Author(s):  
J. T. Kuo ◽  
W.-S. Hsu ◽  
T.-C. Yo
Keyword(s):  
Combustion Efficiency ◽  
Pollutant Emissions ◽  
Air Distribution ◽  
Gas Temperature ◽  
One Dimensional ◽  
Supply And Distribution ◽  
Air Supply ◽  
Burning Rates ◽  
Side Walls ◽  
Detailed Chemical

One important aspect of refuse mass-burn combustion control is the manipulation of combustion air. Proper air manipulation is key to the achievement of good combustion efficiency and reduction of pollutant emissions. Experiments, using a small fix-grate laboratory furnace with cylindrical combustion chamber, were performed to investigate the influence of undergrate/sidewall air distribution on the combustion of beds of wood cubes. Wood cubes were used as a convenient laboratory surrogate of solid refuse. Specifically, for different bed configurations (e.g., bed height, bed voidage, bed fuel size, etc.), burning rates and combustion temperatures at different bed locations were measured under various air supply and distribution conditions. One of the significant results of the experimental investigation is that combustion, with air injected from side walls and no undergrate air, has the maximum combustion efficiency. On the other hand, combustion with undergrate air achieves higher combustion rates but with higher CO emissions. A simple one-dimensional model was constructed to derive correlation of combustion rate as a function of flue gas temperature and oxygen concentration. Despite the fact that the model is one-dimensional and many detailed chemical and physical processes of combustion are not considered, comparisons of the model predictions and the experimental results indicate that the model is appropriate for quantitative evaluation of bed-burning rates.

100% Test Burn of Torrefied Wood Pellets at a Full-Scale Pulverized Coal Fired Utility Steam Generator

2018 ◽  
Author(s):  
Rod Hatt ◽  
David A. T. Rodgers ◽  
Randy Curtis
Keyword(s):  
Electrostatic Precipitator ◽  
Combustion Efficiency ◽  
Pulverized Coal ◽  
Powder River Basin ◽  
Wood Production ◽  
Wood Pellets ◽  
Front End ◽  
Combustion Emissions ◽  
And Storage ◽  
Test Fuel

Portland General Electric’s (PGE) Boardman plant is a nominal 600 megawatt (MW) coal fired unit that burns sub-bituminous Powder River Basin (PRB) coal from Wyoming. This paper will cover the experience and results of PGE’s Boardman plant operating on 100% torrefied wood (TW) pellets at 255 MW consuming almost 5000 tons of pellets. Results were positive and include suitable handing after inclement weathering for months. Pulverizers were able to handle the TW pellets with adjustments, resulting in near 100% combustion efficiency. Particulates were controlled with an electrostatic precipitator (ESP). Topics investigated include torrefied wood production, fuel handling and storage on the front end of the test. Fuel handling, pulverization, combustion, emissions, and ESP performance were monitored during the test and are reported here. Several one mill tests were conducted prior to the 100% test to evaluate and improve mill performance. This test showed that a pulverized coal (PC) boiler can operate on 100% TW fuel with minimal operational changes.

Intake-Air Oxygen-Enrichment of Diesel Engines as a Power Enhancement Method and Implications on Pollutant Emissions

2009 ◽  
Author(s):  
Theodoros C. Zannis ◽  
Dimitrios T. Hountalas ◽  
Elias A. Yfantis ◽  
Roussos G. Papagiannakis ◽  
Yiannis A. Levendis
Keyword(s):  
Theoretical Investigation ◽  
Diesel Engines ◽  
Equivalence Ratio ◽  
Combustion Efficiency ◽  
Oxygen Enrichment ◽  
Pollutant Emissions ◽  
Particulate Emissions ◽  
Engine Simulation ◽  
Hc Emissions ◽  
Experimental Findings

Increasing the in-cylinder oxygen availability of diesel engines is an effective method to improve combustion efficiency and to reduce particulate emissions. Past work on oxygen-enrichment of the intake air, revealed a large decrease of ignition delay, a remarkable decrease of soot emissions as well as reduction of CO and unburned hydrocarbon (HC) emissions while, brake specific fuel consumption (bsfc) remained unaffected or even improved. Moreover, experiments conducted in the past by authors revealed that oxygen-enrichment of the intake air (from 21% to 25% oxygen mole fraction) under high fuelling rates resulted to an increase of brake power output by 10%. However, a considerable increase of NOx emissions was recorded. This manuscript, presents the results of a theoretical investigation that examines the effect of oxygen enrichment of intake air, up to 30%v/v, on the local combustion characteristics, soot and NO concentrations under the following two in-cylinder mixing conditions: (1) lean in-cylinder average fuel/oxygen equivalence ratio (constant fuelling rate) and (2) constant in-cylinder average fuel/oxygen equivalence ratio (increased fuelling rate). A phenomenological engine simulation model is used to shed light into the influence of the oxygen content of combustion air on the distribution of combustion parameters, soot and nitric oxide inside the fuel jet, in all cases considered. Simulations were made for a naturally aspirated single-cylinder DI diesel engine “Lister LV1” at 2500 rpm and at various engine loads. The outcome of this theoretical investigation was contrasted with published experimental findings.

scholarly journals Thermodynamic Analysis of Iron Ore Sintering Process Based on Biomass Carbon

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5988
Author(s):  
Mi Zhou ◽  
Zhenyu Yu ◽  
Panlei Wang ◽  
Huaqing Xie ◽  
Yongcai Wen ◽  
...  
Keyword(s):  
Thermodynamic Analysis ◽  
Iron Ore ◽  
Sinter Process ◽  
Great Influence ◽  
Pollutant Emissions ◽  
Coke Breeze ◽  
Maximum Temperature ◽  
Biomass Carbon ◽  
Metallurgical Properties ◽  
Pollutant Gases

The sinter process of iron ore with biomass carbon instead of coke breeze as fuel was investigated via thermodynamic analysis in this paper through a comparison of sinter composition indexes, metallurgical properties, and pollutant emissions. Straw charcoal was used in this paper, and its replacement does not adversely affect the composition index of iron ore, namely Fe, FeO, basicity, S, nor the metallurgical properties, namely reduction degradation index and reduction index. However, the replacement has a great effect on the emissions of pollutant gases, including SO2, NOx, CO, and CO2. The thermodynamic analysis result shows that emissions of pollutant gases produced in the sinter process significantly decrease by using straw charcoal instead of coke breeze in sinter. The sintering maximum temperature has a great influence on sintering technical indicators. The best sintering maximum temperature is between 1300 and 1400 °C, where sinter ore with high quality can be obtained.

scholarly journals Experimental and Computational Study of Trapped Vortex Combustor Sector Rig with High-Speed Diffuser Flow

2001 ◽  
Vol 7 (6) ◽  
pp. 375-385 ◽  
Author(s):  
R. C. Hendricks ◽  
D. T. Shouse ◽  
W. M. Roquemore ◽  
D. L. Burrus ◽  
B. S. Duncan ◽  
...  
Keyword(s):  
Gas Turbine ◽  
High Speed ◽  
Fuel Injection ◽  
Computational Study ◽  
Combustion Efficiency ◽  
Flame Stabilization ◽  
Performance Data ◽  
Pollutant Emissions ◽  
Choked Flow ◽  
Trapped Vortex

The Trapped Vortex Combustor (TVC) potentially offers numerous operational advantages over current production gas turbine engine combustors. These include lower weight, lower pollutant emissions, effective flame stabilization, high combustion efficiency, excellent high altitude relight capability, and operation in the lean burn or RQL modes of combustion. The present work describes the operational principles of the TVC, and extends diffuser velocities toward choked flow and provides system performance data. Performance data include EINOx results for various fuel-air ratios and combustor residence times, combustion efficiency as a function of combustor residence time, and combustor lean blow-out (LBO) performance. Computational fluid dynamics (CFD) simulations using liquid spray droplet evaporation and combustion modeling are performed and related to flow structures observed in photographs of the combustor. The CFD results are used to understand the aerodynamics and combustion features under different fueling conditions. Performance data acquired to date are favorable compared to conventional gas turbine combustors. Further testing over a wider range of fuel-air ratios, fuel flow splits, and pressure ratios is in progress to explore the TVC performance. In addition, alternate configurations for the upstream pressure feed, including bi-pass diffusion schemes, as well as variations on the fuel injection patterns, are currently in test and evaluation phases.

Development of a Low NOx Combustor for 300kW-Class Ceramic Gas Turbine (CGT302)

1998 ◽  
Author(s):  
A. Okuto ◽  
T. Kimura ◽  
I. Takehara ◽  
T. Nakashima ◽  
Y. Ichikawa ◽  
...  
Keyword(s):  
Research And Development ◽  
Gas Turbine ◽  
Flow Rate ◽  
Gas Turbines ◽  
Combustion Efficiency ◽  
Development Project ◽  
Pollutant Emissions ◽  
Inlet Temperature ◽  
Outlet Temperature ◽  
Nox Emissions

Research and development project of ceramic gas turbines (CGT) was started in 1988 promoted by the Ministry of International Trade and Industry (MITI) in Japan. The target of the CGT project is development of a 300kW-class ceramic gas turbine with a 42 % thermal efficiency and a turbine inlet temperature (TIT) of 1350°C. Three types of CGT engines are developed in this project. One of the CGT engines, which is called CGT302, is a recuperated two-shaft gas turbine for co-generation use. In this paper, we describe the research and development of a combustor for the CGT302. The project requires a combustor to exhaust lower pollutant emissions than the Japanese regulation level. In order to reduce NOx emissions and achieve high combustion efficiency, lean premixed combustion technology is adopted. Combustion rig tests were carried out using this combustor. In these tests we measured the combustor performance such as pollutant emissions, combustion efficiency, combustor inlet/outlet temperature, combustor inlet pressure and pressure loss through combustor. Of course air flow rate and fuel flow rate are controlled and measured, respectively. The targets for the combustor such as NOx emissions and combustion efficiency were accomplished with sufficient margin in these combustion rig tests. In addition, we report the results of the tests which were carried out to examine effects of inlet air pressure on NOx emissions here.

The Development of a Neural Network Based System for the Optimal Control of Chain-Grate Stoker-Fired Boilers

2000 ◽  
Author(s):  
A. Z. S. Chong ◽  
S. J. Wilcox ◽  
J. Ward
Keyword(s):  
Neural Network ◽  
Steady State ◽  
Pilot Scale ◽  
Combustion Efficiency ◽  
Fine Tuning ◽  
Pollutant Emissions ◽  
Test Facility ◽  
Test Results ◽  
Load Following ◽  
Online Implementation

Abstract A novel Neural Network Based Controller (NNBC) was developed following a comprehensive set of experiments carried out on a pilot-scale stoker test facility at CRE Group Ltd., U.K. The NNBC mimicked the actions of an expert boiler operator, by providing ‘near optimum’ settings of coal feed and air flow, as well as ‘staging’ these parameters during load following conditions, before fine tuning the combustion air under quasi-steady-state conditions. Test results from the online implementation of the NNBC have demonstrated that improved transient and steady-state combustion conditions were attained. The prototype NNBC thus provides both stoker manufacturers and users with a means of reducing pollutant emissions, as well as improving the combustion efficiency of this type of coal firing equipment.

Effects of Firing Mode on the Performance of Flameless Combustion: A Review Paper

2013 ◽  
Vol 388 ◽  
pp. 206-212
Author(s):  
Ali Abuelnuor Abdeen Abuelnuor ◽  
Mazlan Abdul Wahid ◽  
Aminuddin Saat ◽  
Mohsin M. Sies ◽  
Mohamed Osman Abdalla ◽  
...  
Keyword(s):  
Energy Savings ◽  
High Efficiency ◽  
Review Paper ◽  
Combustion Efficiency ◽  
Pollutant Emissions ◽  
Pollutant Emission ◽  
Flameless Combustion ◽  
Auto Ignition ◽  
Firing Mode ◽  
Industrial Heating

Flameless combustion is of a great interest since it simultaneously provides higher thermal efficiency together with controlling the pollutant emission such as NOX. This technology has been used to provide large energy savings in power system and industrial heating applications. In this technology, the preheat temperature of the combustion air must be higher than the auto-ignition temperature of the reactant mixture. In this review, papers concern the effect of firing mode to reduce pollutant emissions such as NOX emission and combustion efficiency for flameless combustion were reviewed. Summaries on the influences of the firing mode in the flameless combustion were presented, discussed and analyzed. The review concludes that all the previous studies have asserted that a parallel firing mode gives much lower pollutant emissions and high efficiency compared with staggered and counter modes.

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