Laboratory study of the effects of moisture content on heat transfer and combustion efficiency of three biomass cook stoves

2008 ◽  
Vol 12 (2) ◽  
pp. 66-77 ◽  
Author(s):  
Ernestine A.T. Yuntenwi ◽  
Nordica MacCarty ◽  
Dean Still ◽  
Jürgen Ertel
Keyword(s):  
Heat Transfer ◽  
Moisture Content ◽  
Laboratory Study ◽  
Combustion Efficiency ◽  
Cook Stoves

scholarly journals Using Design Thinking to Improve Cook Stoves Development in Mexico

2021 ◽  
Vol 13 (7) ◽  
pp. 3843
Author(s):  
Elena Ferriz Bosque ◽  
Luisa M. Muneta ◽  
Gregorio Romero Rey ◽  
Berta Suarez
Keyword(s):  
Developing Countries ◽  
Design Thinking ◽  
Combustion Efficiency ◽  
Residential Energy ◽  
Traditional Use ◽  
Design Changes ◽  
Need To Evaluate ◽  
Cook Stoves ◽  
Design Options ◽  
Theoretical Analyses

A traditional use of bioenergy is the main source of residential energy in developing countries, essentially using firewood to cook, boil water or heating affecting people in developing countries. Improved kitchens are more efficient and less polluting, and there is a need to evaluate different design options to facilitate their adoption. There are different types of very economical improved cook stoves with high combustion efficiency. In Mexico, multiple projects about cook stoves have been carried out, the root of this study being one of them, the Patsari cook stoves. The goal of this project was to modify previous designs to align with the habits and traditions. This study shows the importance of including the participation of the users in the design of the portable model of the Patsari cook stoves, applying Design Thinking methodology. Many designs or design changes have been done on cook stoves by different researchers, but users do not adapt to them. This article, through a field study, shows the importance of theoretical analyses along with user experiences to facilitate the adoption of these improves cook stoves and ensure their success.

scholarly journals Thermal conductivity and deformation of Taxodium hybrid ‘Zhongshanshan’ during heat transfer process

BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 2645-2655
Author(s):  
Yuehua Zhu ◽  
Yaoli Zhang ◽  
Biao Pan
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Moisture Content ◽  
Transfer Process ◽  
Dimensional Change ◽  
Testing Temperature ◽  
Scientific Basis ◽  
Heat Transfer Process ◽  
Wood Moisture Content ◽  
Wood Moisture

The thermal conductivity and the deformation of wood from the Taxodium hybrid ‘Zhongshanshan’ were studied in the process of heat transfer. The results showed that the average thermal conductivity of this wood was 0.1257 W/(m·K) under the condition of 12% wood moisture content and 30 °C heat transfer temperature. When the testing temperature exceeded 0 °C, the thermal conductivity increased linearly with both temperature and wood moisture content and was affected by the moisture content of the wood. During the heat transfer process, the deformation of features caused repeated swelling and shrinkage in the longitudinal, radial, and tangential directions. The dimensional change was greatly affected by the wood’s moisture content and was less affected by the temperature. These results are of great meaning for the study of the heat transfer process of Taxodium hybrid ‘Zhongshanshan’ wood. Furthermore, it provides a scientific basis for the heat preservation effect, drying treatment, and pyrolysis treatment of Taxodium hybrid ‘Zhongshanshan’ wood for use as a building material.

scholarly journals Isotopic composition of H2from wood burning: Dependency on combustion efficiency, moisture content, andδD of local precipitation

2010 ◽  
Vol 115 (D17) ◽  
Author(s):  
Thomas Röckmann ◽  
Catalina X. Gómez Álvarez ◽  
Sylvia Walter ◽  
Carina van der Veen ◽  
Adam G. Wollny ◽  
...  
Keyword(s):  
Moisture Content ◽  
Isotopic Composition ◽  
Combustion Efficiency ◽  
Wood Burning

scholarly journals Feasibility Study of Co-Firing of Torrefied Empty Fruit Bunch and Coal through Boiler Simulation

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3051
Author(s):  
Yu Jiang ◽  
Kyeong-Hoon Park ◽  
Chung-Hwan Jeon
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Power Plants ◽  
Combustion Efficiency ◽  
Combustion Characteristics ◽  
Unburned Carbon ◽  
Empty Fruit Bunch ◽  
Oxides Of Nitrogen ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics

Torrefied empty fruit bunch (EFB) co-firing is a promising technology to reduce emissions from coal-fired power plants. However, co-firing can influence the combustion and heat transfer characteristics in a coal boiler. In order to study the feasibility of co-firing application of torrefied EFB (T-EFB) in boilers, the combustion characteristics, gas emissions and heat flux distribution were analyzed, respectively. First, the kinetic parameters of T-EFB devolatilization and char oxidation were obtained by experimental analysis. Second, the computational fluid dynamics (CFD) analysis was applied to the actual 500 MWe boiler simulation to further evaluate the differences in the co-firing performance parameters (combustion characteristics and emissions) of the T-EFB and the heat transfer characteristics within the boiler. Numerical results show that T-EFB co-firing can improve the ignition characteristics of pulverized coal, reduce the formation of unburned particles. When the blending ratio was increased from 10% to 50%, significantly NOx (oxides of nitrogen) reduction (levels from 170 to 98 ppm at 6% O2) was achieved. At a blending ratio above 40%, boiler combustion efficiency decreases as the total heat flux of the boiler decreases due to an increase in the amount of unburned carbon. In addition, T-EFB co-firing can affect the heat transfer characteristics of the boiler.

Analysis of Flow Dynamics of Carbon Monoxide Emitted from Cook Stoves in Closed Room Using CFD

2020 ◽  
Vol 15 (3) ◽  
pp. 69-72
Author(s):  
Saurav Raj Bista ◽  
Bivek Baral ◽  
Utsav Raj Aryal ◽  
Nischal Chaulagain
Keyword(s):  
Developing Countries ◽  
Indoor Air ◽  
Indoor Air Pollution ◽  
Heating System ◽  
Combustion Efficiency ◽  
Flow Dynamics ◽  
Indoor Space ◽  
Air Pollutions ◽  
Cook Stoves ◽  
Solid Biomass

Wood being one of the major sources for cooking in developing countries has also been key for indoor air pollutions. Many studies and improvements on the stove have been conducted to enhance combustion efficiency and minimize emission. Although many Improved Cooking Stoves (ICS) programs has been widespread, due to design limitation together with operational and fuel factors have hindered the targeted emission reduction. Several studies in developing countries have shown that the even ICS have not been able to reduce the adverse impact on human health due to the use of solid biomass fuel. Despites the limitation in stove performance, alternatives have to be used to reduce the indoor air pollution till better cooking and heating system is in place in the developing countries. Proper ventilation and stove placement might be one of the few solutions. To provide an effective passive ventilation scheme, flow dynamics of the pollutants from stove to indoor space and outdoor needs to be predicted. This paper discusses about the application of Computational Fluid Dynamics (CFD) tool to predict the pollution flow pattern and dispersion dynamics with different ventilation placement and stove location. The study also considers potential thermal energy conservation in the living space with optimum ventilation.

Convective heat transfer in fire spread through fine fuel beds

2010 ◽  
Vol 19 (3) ◽  
pp. 284 ◽  
Author(s):  
W. R. Anderson ◽  
E. A. Catchpole ◽  
B. W. Butler
Keyword(s):  
Heat Transfer ◽  
Wind Speed ◽  
Moisture Content ◽  
Flame Front ◽  
Free Stream ◽  
Surface Wind ◽  
Surface Wind Speed ◽  
Fuel Moisture ◽  
Fire Front ◽  
Fuel Moisture Content

An extensive set of wind-tunnel fires was burned to investigate convective heat transfer ahead of a steadily progressing fire front moving across a porous fuel bed. The effects of fuel and environmental variables on the gas temperature profile and the ‘surface wind speed’ (gas velocity at the fuel bed surface) are reported. In non-zero winds, the temperature of the air near the fuel bed surface decays exponentially with distance from the fire front. In zero winds, the temperature decreases rapidly within a very short distance of the flame front, then decays slowly thereafter. The maximum air temperature decreases as the free stream wind speed, packing ratio and fuel moisture content increase. The characteristic distance of the exponential decay increases strongly with the free stream wind speed and decreases with the packing ratio and surface area-to-volume ratio of the fuel. The surface wind speed depends strongly on the free stream wind speed, and to a lesser extent on packing ratio, fuel bed depth and fuel moisture content. There are three general regimes for the surface flow: (1) a constant velocity flow of approximately half the free stream flow, far from the flame front; (2) an intermediate zone of minimum flow characterised by low or reversed flow; and (3) a region near the flame front where the velocity rises rapidly almost to the free stream velocity. The boundaries between the three regions move further from the flame front with increasing wind speed, in a way which is only slightly affected by fuel geometry.

An Experimental Investigation of Wood Combustion

1994 ◽  
Vol 116 (3) ◽  
pp. 186-193 ◽  
Author(s):  
A. Dadkhah-Nikoo ◽  
D. J. Bushnell
Keyword(s):  
Experimental Investigation ◽  
Particle Size ◽  
Moisture Content ◽  
Combustion Products ◽  
Combustion Efficiency ◽  
Particulate Emissions ◽  
Fuel Particle ◽  
Wood Combustion ◽  
Part Load ◽  
Excess Air

This paper presents the results from an experimental investigation of wood combustion. Variables chosen for investigation are fuel moisture content, fuel particle size, excess air, fraction and temperature of under-fire air. Influence of the off-design (part load) operation of the combustion unit on combustion efficiency and particulate emission is also investigated. Data recorded during the experiments include the composition and temperature of the combustion products, particulate emissions, and combustible fraction of the particulate. Based on the experimental data, a linear regression model was developed to investigate the variables affecting the combustion process. A computer model was used to calculate the temperature and composition of the combustion products under adiabatic conditions. Results of the adiabatic model and the experimental regression analysis are compared and discussed. According to the results presented, it is concluded that the combustion efficiency and particulate emissions are most influenced by the factors that increase the volume of the combustion products in the combustion chamber. These variables include excess air, moisture content of the fuel, and the combustion air temperature. Fuel particle size and the fraction of under-fire air did not significantly affect the combustion efficiency and particulate emissions. It is also concluded that the off-design (part-load) operation of the combustion unit, results in higher particulate emissions and lower combustion efficiency.

Effect of moisture content on ammonia emissions from broiler litter: A laboratory study

2007 ◽  
Vol 58 (1) ◽  
pp. 41-53 ◽  
Author(s):  
Zifei Liu ◽  
Lingjuan Wang ◽  
David Beasley ◽  
Edgar Oviedo
Keyword(s):  
Moisture Content ◽  
Laboratory Study ◽  
Ammonia Emissions ◽  
Broiler Litter ◽  
Effect Of Moisture

Analysis on Heat Transfer Intensity of Bamboo Structure Wall in Warm and Humid Environment

2013 ◽  
Vol 639-640 ◽  
pp. 721-726
Author(s):  
Ji Bo Long ◽  
Ping Wang ◽  
Yu Lou Li ◽  
Si Yi Huang
Keyword(s):  
Heat Transfer ◽  
Temperature Gradient ◽  
Moisture Content ◽  
Heat Storage ◽  
Temperature Wave ◽  
Storage Coefficient ◽  
Humid Environment ◽  
Heat Transfer Capacity ◽  
Bamboo Structure ◽  
Total Moisture Content

Based on the fundamentals of heat and moisture transfer in porous media, characteristics of heat transfer intensity of a bamboo structure wall are analyzed when the moisture content changes under the action of natural warm and humid environment. The results show that: when the moisture content changes, the effective coefficient of heat conductivity and specific heat capacity of bamboo both change, and physical parameters (e.g., heat transfer capacity, heat storage capacity, temperature distribution, attenuation coefficient of temperature wave, delay coefficient of temperature wave) all change accordingly. When the total moisture content of the wall increases, the temperature difference between inside and outside surfaces of the wall is reduced, and attenuation and delay coefficient of temperature wave both increase. All of these improve the thermal comfort of indoor environment, but the heat transfer capacity through the wall increases. If the total moisture content of the wall is constant and the moisture distribution along the thickness direction of the wall changes, the temperature gradient decreases and the heat storage coefficient increases in bamboo layer of high moisture content, and the temperature gradient increases and the heat storage coefficient decreases in bamboo layer of low moisture content.

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