For Retrofit Applications of Biomass Briquette Industrial Boilers

2014 ◽  
Vol 716-717 ◽  
pp. 813-816
Author(s):  
Chao Cheng ◽  
Guo Min Fu ◽  
Wei Lv ◽  
Xi Yu Lin
Keyword(s):  
Combustion Efficiency ◽  
Front Wall ◽  
Boiler Furnace ◽  
Biomass Boiler ◽  
Air Supply ◽  
Before And After ◽  
Industrial Boiler ◽  
Industrial Boilers ◽  
Secondary Air ◽  
Lower Biomass

Lower biomass briquette fuel Combustion efficiency for Stream-chain Boiler furnace burning dyeing factory,the existing Furnace arch configuration easily lead the front burning,easy to burn coal gate and ignite fuel bin.Proposed through the transformation of traditional industrial boiler feed systems,before and after the boiler arch configuration,add dedusting equipment,add the secondary air system and adjust primary air supply system to improve the boiler,which can effectively improve the combustion efficiency,to solve the question of coal gate back burning bad front wall and ignite fuel bin.Ease dust accumulation and slagging problems in the biomass boiler.

Research on Energy-Saving Control Technology of Boiler

2011 ◽  
Vol 383-390 ◽  
pp. 2603-2607
Author(s):  
Yao Yi ◽  
Guang Jian Chen ◽  
Jin Ling Jia
Keyword(s):  
Energy Saving ◽  
Intelligent Control ◽  
Flue Gas ◽  
Combustion Efficiency ◽  
Wind Pressure ◽  
Boiler Furnace ◽  
Door Opening ◽  
Boiler Efficiency ◽  
Secondary Air ◽  
Energy Saving Control

Focusing on energy-saving issues of boiler, this paper finds out the combustion conditions inside boiler furnace by monitoring and analysis on oxygen content of flue gas, carbon content of fly ash, CO and CO2 contents. The intelligent control of boiler combustion was achieved and combustion efficiency was rosen. Using neural network controlling model, automatic optimization of oxygen delivery volume,coal delivery volume, the total wind pressure of primary air, the secondary air-door opening degree and furnace negative pressure were achieved, and the boiler efficiency increasing by 5 ~ 7%.

scholarly journals An adaptive approach to duct optimization of an industrial boiler air supply system using airfoils

2021 ◽  
pp. 157-157
Author(s):  
Branimir Stojiljkovic ◽  
Marta Trninic
Keyword(s):  
Numerical Solutions ◽  
Measured Data ◽  
Supply System ◽  
Experimental Measurements ◽  
Cfd Simulations ◽  
Air Supply ◽  
Industrial Boiler ◽  
Industrial Boilers ◽  
Volume Method ◽  
Level Of Agreement

The purpose of this paper is to examine the pressure drop caused by placing an airfoil at different angles of attack in the straight part of the rectangular air duct, as the first step of investigating the possibility of using a staggered cascade of airfoils for gradual deflection of the airflow in radial elbows of an air supply system used in industrial boilers. The initial problem was approached by using the commercial CFD code based on the Finite Volume Method (FVM) to numerically simulate a 2D incompressible turbulent flow and by conducting direct experimental measurements in the wind tunnel. The results of CFD simulations have been compared to experimentally measured data for two considered cases of inlet velocities and five different angles of attack. Numerical solutions show an adequate level of agreement with experimental measurements. The obtained results indicate the possibility of using a staggered cascade of airfoils for gradual deflection of the airflow.

Optimization of Secondary Air Distribution in Biomass Boiler by CFD Analysis

2016 ◽  
Vol 832 ◽  
pp. 231-237 ◽  
Author(s):  
Martin Lisý ◽  
Jiří Pospíšil ◽  
Otakar Štelcl ◽  
Michal Špilaček
Keyword(s):  
Combustion Chamber ◽  
Flue Gas ◽  
Gas Flow ◽  
Air Distribution ◽  
Cfd Modelling ◽  
Biomass Boiler ◽  
Air Supply ◽  
Secondary Air ◽  
Emission Limits ◽  
The Impact

This paper deals with a use of CFD modelling for optimization of supply of secondary combustion air in the two-chamber biomass boiler combusting very wet biomass (capacity ca. 200 kW). Objective of the analyse is to observe the impact of diameter of a secondary air supply pipe and air flow velocity on mixing of the secondary air with flue gas in the combustion chamber. The numerical model of the experimental boiler was build up for subsequent utilizing of CFD computation based on finite element method. The commercial code STAR-CD was used for carried out parametrical studies. Series of calculations were carried out for four different diameters of air distribution pipes and for 3 different air velocities in distribution orifice. Quality of air dispersion in flue gas flow was assessed in the vertical cross section lead in the end of the combustion chamber. The results of calculation were verified on the experimental installation of the boiler. Influence of secondary air mixing on emission production was measured and analysed. Emissions of pollutants for recommended air distribution comply with emission limits stipulated in the most stringent class 5 according to ČSN-EN 303-5 as well as with emission limits under Regulation No. 405/2012 Sb.

Modeling and Experiment on Combustion Characteristics for Biomass Rotary Burner

2020 ◽  
Vol 04 ◽  
Author(s):  
Guohai Jia ◽  
Lijun Li ◽  
Li Dai ◽  
Zicheng Gao ◽  
Jiping Li
Keyword(s):  
Combustion Chamber ◽  
Combustion Temperature ◽  
Combustion Efficiency ◽  
Middle Part ◽  
Combustion Characteristics ◽  
Maximum Temperature ◽  
Excess Air ◽  
Element Simulation ◽  
Excess Air Coefficient ◽  
Secondary Air

Background: A biomass pellet rotary burner was chosen as the research object in order to study the influence of excess air coefficient on the combustion efficiency. The finite element simulation model of biomass rotary burner was established. Methods: The computational fluid dynamics software was applied to simulate the combustion characteristics of biomass rotary burner in steady condition and the effects of excess air ratio on pressure field, velocity field and temperature field was analyzed. Results: The results show that the flow velocity inside the burner gradually increases with the increase of inlet velocity and the maximum combustion temperature is also appeared in the middle part of the combustion chamber. Conclusion: When the excess air coefficient is 1.0 with the secondary air outlet velocity of 4.16 m/s, the maximum temperature of the rotary combustion chamber is 2730K with the secondary air outlet velocity of 6.66 m/s. When the excess air ratio is 1.6, the maximum temperature of the rotary combustion chamber is 2410K. When the air ratio is 2.4, the maximum temperature of the rotary combustion chamber is 2340K with the secondary air outlet velocity of 9.99 m/s. The best excess air coefficient is 1.0. The experimental value of combustion temperature of biomass rotary burner is in good agreement with the simulation results.

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.

High Fidelity Modeling of the Acceleration of a Turboshaft Engine During a Restart

2018 ◽  
Author(s):  
Antoine Ferrand ◽  
Marc Bellenoue ◽  
Yves Bertin ◽  
Radu Cirligeanu ◽  
Patrick Marconi ◽  
...  
Keyword(s):  
Initial Conditions ◽  
Combustion Efficiency ◽  
High Fidelity ◽  
Gas Generator ◽  
Idle Speed ◽  
Flight Mode ◽  
System States ◽  
Secondary Air ◽  
Turboshaft Engine ◽  
High Level

In order to decrease the fuel consumption, a new flight mode is being considered for twin-engine helicopters, in which one engine is put into sleeping mode (a mode in which the gas generator is kept at a stabilized, sub-idle speed by means of an electric motor, with no combustion), while the remaining engine operates at nominal load. The restart of the engine in sleeping mode is therefore deemed critical for safety reasons. This efficient new flight mode has raised the interest in the modeling of the restart of a turboshaft engine. In this context, the initial conditions of the simulations are better known relative to a ground start, in particular the air flow through the gas generator is constant, the fuel and oil system states are known and temperatures of the casings are equal to ambient. During the restart phase of the engine, the gas generator speed is kept at constant speed until the light-up is detected by a rise in inter-turbine temperature, then the starter torque increases, accelerating the engine towards idle speed. In this paper, the modeling of the acceleration of the gas generator from light-up to idle and above idle speeds is presented. Details on the light-up process are not addressed here. The study is based on the high-fidelity aero-thermodynamic restart model that is currently being developed for a 2000 horse power, free turbine turboshaft. In this case, the term high-fidelity refers not only to the modeling of the flow path components but it also includes all the subsystems, secondary air flows and controls with a high level of detail. The physical phenomena governing the acceleration of the turboshaft engine following a restart — mainly the transient evolution of the combustion efficiency and the power loss by heat soakage — are discussed in this paper and modeling solutions are presented. The results of the simulations are compared to engine test data, highlighting that the studied phenomena have an impact on the acceleration of the turboshaft engine and that the model is able to correctly predict acceleration trends.

scholarly journals OPTIMALIZATION OF AFTERBURNER CHANNEL IN BIOMASS BOILER USING CFD ANALYSIS

2016 ◽  
Vol 56 (5) ◽  
pp. 379-387 ◽  
Author(s):  
Jiří Pospíšil ◽  
Martin Lisý ◽  
Michal Špiláček
Keyword(s):  
Cross Sections ◽  
Flue Gas ◽  
Air Distribution ◽  
Cfd Analysis ◽  
Mixing Process ◽  
Rectangular Duct ◽  
Biomass Boiler ◽  
Cross Section Area ◽  
Section Area ◽  
Secondary Air

This contribution presents the results of parametrical studies focused on the mixing process in a small rectangular duct within a biomass boiler. The first study investigates the influence of a local narrowing located in the central part of the duct. This narrowing works as an orifice with very simple rectangular geometry. Four different free cross sections of the orifice were considered in the center of the duct, namely 100%, 70%, 50%, 30% of free cross section area in the duct. The second study is focused on the investigation of the influence of secondary air distribution pipe diameter on the mixing process in a flue gas duct without a narrowing.

Reduction of Pollutant Emissions From Industrial Boilers by Combustion Modification

1977 ◽  
Vol 99 (3) ◽  
pp. 320-328 ◽  
Author(s):  
G. A. Cato ◽  
R. E. Hall ◽  
L. J. Muzio
Keyword(s):  
Flue Gas ◽  
Pollutant Emissions ◽  
Particulate Emissions ◽  
Test Program ◽  
Utility Boilers ◽  
Boiler Efficiency ◽  
Before And After ◽  
Particulate Size ◽  
Oil And Natural Gas ◽  
Industrial Boilers

The use of combustion modification has enabled many utility boilers to meet the emission standards for NOx. Its usefulness in reducing NOx emissions from industrial boilers (ranging from 11 GJ/hr to 528 GJ/hr) has been investigated during a recently completed field test program. The gaseous and particulate emissions from coal, oil, and natural-gas fuels were measured both before and after the combustion modification. Data were taken on particulate size as well as concentration. The principal combustion modification methods that were investigated included reduced excess combustion air, staged combustion air, recirculated flue gas, tuned burners, and reset burner registers. Staging was implemented by the use of overfire air ports or by turning off the fuel to some burners and increasing the fuel to others, thus creating zones of fuel-rich combustion. All of the combustion modification methods were effective to varying degrees in reducing the nitrogen oxides emissions, and reductions of as much as 50 percent were obtained with several of the modifications. In most instances the boiler efficiency was not degraded, although the particulate emissions increased by up to 50 percent in some cases. There was no substantive effect on the other pollutant emissions that were measured.

Coal-Oil Mixtures for Industrial Boilers

1980 ◽  
Author(s):  
Jon Wilda ◽  
Joe Cochran
Keyword(s):  
Department Of Energy ◽  
Private Firms ◽  
Petroleum Resources ◽  
Oil Mixtures ◽  
Industrial Boiler ◽  
Industrial Boilers ◽  
The One

As petroleum resources become more costly and less plentiful, alternative forms of energy are being considered. Composite fuels, of which coal-oil mixtures is the most common, have received relatively minor attention until now even though it is the one alternative utilizing existing technology. Industrial boiler demonstrations of COM fuel are being performed by the Department of Energy and a number of private firms. Ideally, COM can be handled by the same equipment currently used by No. 6 oil systems. Environmental and operating problems occur, due to the coal portion of the mixture, but these are being quickly resolved. Paper published with permission.

The Study of Combustion of Municipal Waste in a Fluidised Bed Combustor

2003 ◽  
Author(s):  
I. Gulyurtlu ◽  
T. Crujeira ◽  
P. Abelha ◽  
D. Boavida ◽  
J. Seabra ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Combustion Efficiency ◽  
Solid Particles ◽  
Gaseous Pollutants ◽  
Fluidised Bed ◽  
Combustion Gases ◽  
Air Supply ◽  
Control Devices ◽  
Emission Limits ◽  
Bed Material

The combustion behaviour of municipal solid waste was studied in a pilot fluidised bed combustor. The waste was pelletised prior to its use. Both co-firing with coal and combustion of waste alone were under taken. The combustion studies were carried out on the pilot installation of INETI. The fluidised bed combustor is square in cross section with each side being 300 mm long. Its height is 5000 mm. There is a second air supply to the freeboard at different heights to deal with high volatile fuels. There was a continuous monitoring of the temperatures in the bed, as well as the composition of the combustion gases. The combustion gases leaving the reactor were let go through the recycling cyclone first to capture most of particulates elutriated out of the combustor. There was a second cyclone which was employed with the aim of increasing the overall efficiency of collecting solid particles. The gaseous pollutants leaving the stack were sampled under iso-kinetic conditions for particulate matter, chlorine compounds and heavy metals. The ash streams were characterised for heavy metals. The results obtained were compared with national legislation. The results obtained suggest that i) the combustion efficiency was very high, ii) there was an enrichment of ashes with heavy metals in the cyclones compared to the bed material, iii) in general, the gaseous pollutants were below the permited limits, and iv) for the compliance with the new European Directive for stricter emission limits adequate control devices, like bag filters, should be integrated with RDF combustion.

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