scholarly journals Low Emissions Resulting from Combustion of Forest Biomass in a Small Scale Heating Device

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5495
Author(s):  
Karol Tucki ◽  
Olga Orynycz ◽  
Andrzej Wasiak ◽  
Antoni Świć ◽  
Leszek Mieszkalski ◽  
...  
Keyword(s):  
Combustion Process ◽  
The Other ◽  
Screw Conveyor ◽  
Small Scale ◽  
Heat Output ◽  
Maximum Heat ◽  
Heating Device ◽  
Air Supply ◽  
Low Emission ◽  
Secondary Air

The paper concerns the analysis of harmful emissions during the combustion process in households. The subject of the analysis is a low emission heating device with an output of 50 kW for burning biomass of forest origin (low-quality hardwoods or softwoods). The proposed boiler is automatically fed from the connected container by means of a screw conveyor. In this way, the optimum amount of fuel is supplied for maximum heat output (adjustment of the ratio of primary air to fuel). The proposed biomass heating system is equipped with a primary and secondary air supply system and exhaust gas sensors. This ensures optimal regulation of the air mixture and efficient and clean combustion. Proper control of the combustion process, control of the air supply by means of a lambda sensor and power control of the system ensure a low-emission combustion process. The system precisely adjusts to the heat demand. This results in highly efficient heating technology with low operating costs. In the presented work, the emission of exhaust gases from the proposed heating device during the combustion of woodchips and beech–oak pellets were measured. It is demonstrated that the proposed design of the boiler equipped with intelligent control significantly reduces emissions when the biomass solid fuels are used, e.g., CO emissions from beech and oak chips and pellets in the low-emission boiler—18 extract pipes shows the value <100 ppm, which is even lower than when gas is burned in the other boilers; on the other hand, the pine chips show even higher emission when burned in the low-emission burner. Consequently, the choice of biomass source and form of the fuel play some role in the emissions observed.

Numerical Simulation of Combustion Process in a 350t/d MSW Incinerator

2012 ◽  
Vol 268-270 ◽  
pp. 898-901
Author(s):  
Shui E Yin ◽  
Jun Wu
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Combustion Process ◽  
Species Distributions ◽  
Complete Combustion ◽  
Operational Conditions ◽  
Furnace Outlet ◽  
Air Supply ◽  
Total Temperature ◽  
Secondary Air

A mathematical model was presented for the combustion of municipal solid waste in a 350t/d MSW-burning incinerator. Numerical simulations were performed to predict the temperature and the species distributions in the furnace, with practical operational conditions taken into account. When the total air supply is constant, reducing primary air and increasing secondary air properly results in the higher total temperature of the furnace and the more oxygen concentration at the furnace outlet, and thereby contributes to the complete combustion of combustibles so that an optimal combustion effect can be achieved.

scholarly journals Investigations of combustion process in combined cooker-boiler fired on solid fuels

2006 ◽  
Vol 10 (4) ◽  
pp. 121-130
Author(s):  
Dragoslava Stojiljkovic ◽  
Vladimir Jovanovic ◽  
Milan Radovanovic ◽  
Nebojsa Manic ◽  
Ivo Radulovic
Keyword(s):  
Flue Gas ◽  
Combustion Process ◽  
Solid Fuels ◽  
Gas Temperature ◽  
Weight Changes ◽  
Complete Combustion ◽  
Air Supply ◽  
Class 1 ◽  
Secondary Air ◽  
Co Emission

The aim of the investigation was to make some reconstructions on the existing stove used for cooking and baking and to obtain the combined cooker-boiler which will fulfill the demands of European standard EN 12815. Implementation of modern scientific achievements in the field of combustion on stoves and furnaces fired on solid fuels was used. During the investigations four various constructions were made with different fresh air inlet and secondary air supply with the intention to obtain more complete combustion with increased efficiency and reduced CO emission. Three different fuels were used: firewood, coal, and wood briquette. A numerous parameters were measured: fuel weight changes during the combustion process, temperature of inlet and outlet water, flue gas composition (O2, CO, SO2, CO2, NOx), flue gas temperature, ash quantity etc. The result of the investigations is the stove with the efficiency of more than 75% - boiler Class 1 (according EN 12815) and CO emission of about 1% v/v. The results obtained during the measurements were used as parameters for modeling of combustion process. .

scholarly journals Aerodynamic Characteristics of the Combustion Process of Sawdust in a Vortex Furnace with Counter-Swirling Flows

2021 ◽  
pp. 68-78
Author(s):  
Rafael Dzhyoiev ◽  
◽  
Andrei Redko ◽  
Igori Redko ◽  
Iuryi Pivnenko ◽  
...  
Keyword(s):  
Numerical Study ◽  
Angular Rate ◽  
Combustion Process ◽  
Aerodynamic Characteristics ◽  
Vortex Furnace ◽  
Saw Dust ◽  
Air Supply ◽  
Air Flows ◽  
Secondary Air ◽  
Furnace Height

The aim of this work is to study the working processes of burning the low-quality fuels, namely, the saw dust in the swirling-type furnaces with an opposite twisted motion of the air. The goal was achieved using the physical and mathematical modeling of the flows interaction. The article presented the results of numerical study of aerodynamic characteristics of burning the saw dust in the swirling-type furnace with the opposite twisted air flows. For the research, the facility was used for the saw dust burning with the air supply into the lower and upper zones of burning. The most essential result of the work was modeling of the working process at the ratio of the flows of the primary air and secondary air without the fuel admixture, equal to 0.2. The tangential rate of the flow changed according to the horizontal sections from 3-5 m/s to 40-42 m/s and with respect to the furnace height from 51 m/s to 30 m/s. The average angular rate of the mixture changed relatively the furnace height in the ranges of 171-500 l/s to 100—300 l/s. The significance of the results obtained consists in determination of the possibility of increasing the efficiency of the work of the furnace facilities at the expense of the introduction of the primary and secondary air flows. In this situation, the optimal ratio of consumptions of primary and secondary air was 0.2. Thus, in this work the consumption of primary air was 1.285 kg/s, the consumption of the secondary air was 0.255 kg/s.

Optimization of a Small Scale Pellet Boiler

2010 ◽  
Author(s):  
Jose´ Carlos Teixeira ◽  
Rui Ferreira ◽  
Manuel Eduardo Ferreira
Keyword(s):  
Heat Dissipation ◽  
High Efficiency ◽  
Raw Materials ◽  
Direct Conversion ◽  
Pollutant Emissions ◽  
Small Scale ◽  
Air Supply ◽  
Wide Range ◽  
Great Relevance ◽  
Secondary Air

Environmental concerns and the drive to reduce the dependence on petroleum based fuels brought the use of renewable energies to the forefront. Biomass appears as a very interesting option for direct conversion into heat. In this context, densified forms of biomass such as pellets are of great relevance because of their easy of use, high efficiency and low emissions. Expected trends in the biomass market suggest that equipments should operate over a wide range of thermal loads and with fuels derived from lower quality raw materials; simultaneously, a high efficiency and low emissions are taken for granted. Currently, biomass domestic boilers prove to be very sensitive to fuel characteristics and load conditions. This work reports on the development of a 15 kW net pellet boiler. A prototype was built that enables the independent control of the air supply into various regions of the combustion chamber and an accurate supply of fuel. The test rig also includes: boiler and flue gases extraction system; feeding system; heat dissipation system; flue gas analyzer; data acquisition system and all sensors. In order to optimize the combustion conditions, pollutant emissions and their relation with feeding conditions, primary and secondary air flow rate and excess of air was analyzed. The results suggest that this burner is a promising for implementation in domestic boilers. The advantages are: CO emissions well below those observed in similar equipments and the capacity to maintain the emissions level constant under different loading conditions.

Numerical Simulation of Turbulent Biogas Combustion

2007 ◽  
Author(s):  
Beibei Yan ◽  
Xuesong Bai ◽  
Guanyi Chen ◽  
Changye Liu
Keyword(s):  
Numerical Simulation ◽  
Mass Flow ◽  
Flame Temperature ◽  
Combustion Process ◽  
Methane Combustion ◽  
Operational Parameters ◽  
Heating Value ◽  
Air Supply ◽  
Methane Flame ◽  
Secondary Air

Operating parameters are considered important for the biogas combustion process and the resulted flame features. The paper investigated the influence of typical parameters through numerical simulation, which include the dimension of combustor, fuel and air mass flow, and secondary air supply. The results from the simulations show that the biogas combustion behaves, to some extent, similarly to the methane combustion, yet significant differences exist between their flames. The combustion process is fairly sensitive to the geometrical and operational parameters. Biogas flame temperature is even lower compared to the methane flame temperature because biogas contains CO2 resulting in low heating value, therefore it is not straightforward to obtain stable combustion. Preheated secondary air or reduced its mass flow may have to be used in this case.

Simulation of a Small Scale Pellet Boiler

2009 ◽  
Author(s):  
J. C. F. Teixeira ◽  
B. N. Vasconcelos ◽  
M. E. C. Ferreira
Keyword(s):  
Combustion Chamber ◽  
Flue Gases ◽  
Fine Tuning ◽  
Small Scale ◽  
Dynamics Model ◽  
No Formation ◽  
Air Supply ◽  
Wide Range ◽  
Secondary Air ◽  
Solid Biomass

A Computational Fluid Dynamics model, implemented in the FLUENT code, has been used to describe with detail the combustion inside the furnace of a 15 kW pellet boiler. The solid biomass is modeled by the reaction of the volatile mater. The air supply is split into two regions with varying AF ratios. It was also observed that the NO formation in the combustion chamber is essentially due to the fuel-NO path and therefore the variations of excess air did not affect the concentration levels of NO at the exit of the combustion chamber. However by increasing the air supply in the vicinity of the grate (by moving the secondary air supply closer to the primary air supply) the NO levels increased. The emissions of the flue gases were measured and compared with the computed results. The results enable the optimization of the combustion chamber design and the efficient fine tuning of a pellet boiler for a wide range of power levels.

scholarly journals Influence of Primary and Secondary Air Supply on Gaseous Emissions from a Small-Scale Staged Solid Biomass Fuel Combustor

2017 ◽  
Vol 32 (4) ◽  
pp. 4212-4220 ◽  
Author(s):  
Thomas Kirch ◽  
Cristian H. Birzer ◽  
Philip J. van Eyk ◽  
Paul R. Medwell
Keyword(s):  
Biomass Fuel ◽  
Small Scale ◽  
Gaseous Emissions ◽  
Air Supply ◽  
Secondary Air ◽  
Solid Biomass Fuel ◽  
Solid Biomass

COMPUTATIONAL AND EXPERIMENTAL STUDIES OF A LOW-EMISSION BURNER FOR A PERSPECTIVE TURBOJET ENGINE WITH THE COMPRESSION RATIO EXCEEDING 40

2020 ◽  
Author(s):  
M. A. Danilov ◽  
◽  
M. V. Drobysh ◽  
A. N. Dubovitsky ◽  
F. G. Markov ◽  
...  
Keyword(s):  
Compression Ratio ◽  
Experimental Studies ◽  
The Other ◽  
Aircraft Engines ◽  
Engine Efficiency ◽  
Other Hand ◽  
Turbojet Engine ◽  
Low Emission ◽  
Civil Aircraft ◽  
The One

Restrictions of emissions for civil aircraft engines, on the one hand, and the need in increasing the engine efficiency, on the other hand, cause difficulties during development of low-emission combustors for such engines.

scholarly journals Analysis of Operational Efficiencies and Costs for Extracting Thinned Woods in Small-Scale Forestry, Nasunogahara Area, Tochigi Prefecture, Japan

2020 ◽  
Vol 3 (1) ◽  
pp. 61
Author(s):  
Kazuhiro Aruga
Keyword(s):  
Transportation Costs ◽  
The Other ◽  
Small Scale ◽  
Light Truck ◽  
Operation Costs ◽  
Other Hand ◽  
Light Trucks ◽  
The Cost ◽  
Manual Extraction ◽  
Truck Transportation

In this study, two operational methodologies to extract thinned woods were investigated in the Nasunogahara area, Tochigi Prefecture, Japan. Methodology one included manual extraction and light truck transportation. Methodology two included mini-forwarder forwarding and four-ton truck transportation. Furthermore, a newly introduced chipper was investigated. As a result, costs of manual extractions within 10 m and 20 m were JPY942/m3 and JPY1040/m3, respectively. On the other hand, the forwarding cost of the mini-forwarder was JPY499/m3, which was significantly lower than the cost of manual extractions. Transportation costs with light trucks and four-ton trucks were JPY7224/m3 and JPY1298/m3, respectively, with 28 km transportation distances. Chipping operation costs were JPY1036/m3 and JPY1160/m3 with three and two persons, respectively. Finally, the total costs of methodologies one and two from extraction within 20 m to chipping were estimated as JPY9300/m3 and JPY2833/m3, respectively, with 28 km transportation distances and three-person chipping operations (EUR1 = JPY126, as of 12 August 2020).

scholarly journals The Synergy of Two Biofuel Additives on Combustion Process to Simultaneously Reduce NOx and PM Emissions

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2784
Author(s):  
Jerzy Cisek ◽  
Szymon Lesniak ◽  
Winicjusz Stanik ◽  
Włodzimierz Przybylski
Keyword(s):  
Heat Release ◽  
Combustion Rate ◽  
Combustion Process ◽  
The Other ◽  
Fuel Additive ◽  
Exhaust Gas ◽  
Synergy Effect ◽  
Engine Exhaust ◽  
Other Hand ◽  
Heat Released

The article presents the results of research on the influence of two fuel additives that selectively affect the combustion process in a diesel engine cylinder. The addition of NitrON® reduces the concentration of nitrogen oxides (NOx), due to a reduction in the kinetic combustion rate, at the cost of a slight increase in the concentration of particulate matter (PM) in the engine exhaust gas. The Reduxco® additive reduces PM emissions by increasing the diffusion combustion rate, while slightly increasing the NOx concentration in the engine exhaust gas. Research conducted by the authors confirmed that the simultaneous use of both of these additives in the fuel not only reduced both NOx and PM emissions in the exhaust gas but additionally the reduction of NOx and PM emissions was greater than the sum of the effects of these additives—the synergy effect. Findings indicated that the waveforms of the heat release rate (dQ/dα) responsible for the emission of NOx and PM in the exhaust gas differed for the four tested fuels in relation to the maximum value (selectively and independently in the kinetic and diffusion stage), and they were also phase shifted. Due to this, the heat release process Q(α) was characterized by a lower amount of heat released in the kinetic phase compared to fuel with NitrON® only and a greater amount of heat released in the diffusion phase compared to fuel with Reduxco® alone, which explained the lowest NOx and PM emissions in the exhaust gas at that time. For example for the NOx concentration in the engine exhaust: the Nitrocet® fuel additive (in the used amount of 1500 ppm) reduces the NOx concentration in the exhaust gas by 18% compared to the base fuel. The addition of a Reduxco® catalyst to the fuel (1500 ppm) unfortunately increases the NOx concentration by up to 20%. On the other hand, the combustion of the complete tested fuel, containing both additives simultaneously, is characterized, thanks to the synergy effect, by the lowest NOx concentration (reduction by 22% in relation to the base). For example for PM emissions: the Nitrocet® fuel additive does not significantly affect the PM emissions in the engine exhaust (up to a few per cent compared to the base fuel). The addition of a Reduxco® catalyst to the fuel greatly reduces PM emissions in the engine exhaust, up to 35% compared to the base fuel. On the other hand, the combustion of the complete tested fuel containing both additives simultaneously is characterized by the synergy effect with the lowest PM emission (reduction of 39% compared to the base fuel).

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