The influence of fuel moisture content on the combustion of Eucalyptus foliage

2013 ◽  
Vol 22 (3) ◽  
pp. 343 ◽  
Author(s):  
Malcolm Possell ◽  
Tina L. Bell
Keyword(s):  
Moisture Content ◽  
Dry Weight ◽  
Co2 Concentration ◽  
Combustion Products ◽  
Combustion Efficiency ◽  
Emission Factors ◽  
Fuel Moisture ◽  
Time To Ignition ◽  
Fuel Moisture Content ◽  
Co Concentrations

Leaves from three species of Eucalyptus were combusted in a mass-loss calorimeter to characterise the effect of fuel moisture on energy release and combustion products for this genus. Increasing moisture content reduced peak heat release and the effective heat of combustion in a negative exponential pattern while simultaneously increasing time-to-ignition. Estimates of the probability of ignition, based upon time-to-ignition data, indicated that the critical fuel moisture content for a 50% probability of ignition ranged from 81 to 89% on a dry-weight basis. The modified combustion efficiency of leaves (the ratio of CO2 concentration to the sum of the CO2 and CO concentrations) decreased exponentially as fuel moisture increased. This was because CO2 concentrations during combustion declined exponentially while CO concentrations increased exponentially. However, CO2 mixing ratios were always greater by at least one order of magnitude. Emission factors for CO2 declined exponentially with increasing fuel moisture content while CO emission factors increased exponentially to a maximum. The emission factors for volatile organic compounds increased in a pattern similar to that for CO with increasing fuel moisture content. The empirical relationships identified in this study have implications for fire-behaviour modelling and assessing the effect of fire on air quality and climate.

A Theoretical Analysis of Predrying of Solid Fuels With Flue Gas

1988 ◽  
Vol 110 (2) ◽  
pp. 119-123 ◽  
Author(s):  
C. M. Kinoshita
Keyword(s):  
Moisture Content ◽  
Flue Gas ◽  
Air Entrainment ◽  
Combustion Efficiency ◽  
Solid Fuels ◽  
Fuel Moisture ◽  
Gas Temperature ◽  
Ambient Conditions ◽  
Dimensionless Parameters ◽  
Fuel Moisture Content

Combustion efficiency and flue-gas drying of solid fuels are analyzed. A simple, universal arithmetic expression for combustion efficiency is developed. This expression involves four primary dimensionless parameters which relate to (and are fixed for given) fuel and ambient conditions, and three secondary dimensionless parameters which relate to (and vary with) fuel moisture content, excess air, and flue-gas temperature. Additional expressions involving the same primary parameters are developed to calculate the decrease in fuel moisture content due to flue-gas drying with and without entrainment of air into the dryer system and the decrease in flue-gas temperature with air entrainment. Values for the four primary parameters are presented for various fuels; their values do not vary much for most biomass fuels.

scholarly journals Análise do conteúdo de umidade foliar de fitofisionomias do Cerrado com uso de imagens do multispectral instrument do satélite Sentinel 2

2020 ◽  
Vol 13 (07) ◽  
pp. 3315
Author(s):  
Leidiane De Paula Rezende ◽  
Ricardo Vicente Ferreira
Keyword(s):  
Moisture Content ◽  
Dry Weight ◽  
Short Wave ◽  
Fuel Load ◽  
Fuel Moisture ◽  
Reflectance Analysis ◽  
Short Wave Infrared ◽  
Atmospheric Variations ◽  
Fuel Moisture Content ◽  
Sentinel 2

O estudo realizou uma análise comparativa entre o índice de reflectância de duas fitofisionomias (Macega e Cerradão) do Cerrado nas bandas de imagens do Instrumento Multiespectral (MSI) do satélite Sentinel 2 das bandas Short-wave infrared (SWIR) 1 e 2 e Near Infra-Red (NIR) de duas fitofisionomias do Cerrado em consonância com os dados in situ de Fuel Moisture Content (FMC) afim de contribuir com técnicas de Sensoriamento Remoto para monitorar combustíveis vegetais e perigos de incêndio. Dados adicionais de variáveis ambientais como temperatura e umidade do ar, e de satélites como precipitação e conteúdo de umidade de solo foram consideradas neste estudo. A análise dos dados foi feita com a aplicação de correlação linear e de regressão múltipla. No FMC, os resultados ficaram acima de 100% para o Cerradão e para a Macega atingiu valor mínimo de 20%. Na análise de correlação, a banda NIR se correlacionou positivamente (R² = 0,32) ao FMC do Cerradão, enquanto na Macega, a melhor correlação foi identificada nas bandas do SWIRs (R² = 0,36) inversamente ao FMC. Na análise de regressão, o FMC do Cerradão indicou correspondência à umidade de solo. Conclui-se que vegetais vivos tendem a recorrer a umidade do solo, enquanto que os vegetais mortos são mais afetados por variáveis atmosféricas e, por isso, são mais propensos a incêndios, como a Macega. O monitoramento do FMC por Sensoriamento Remoto requer maior amostragem em relação ao bioma Cerrado, cuja fisiologia complexa mostra ser influenciada por variáveis ambientais e climáticas que deverão ser levadas em conta em análises e estudos posteriores.  Leaf moisture content analysis of Cerrado phytophysiognomies using Sentinel 2 satellite multispectral instrument images   A B S T R A C T Moisture content of living or dead plant material is a fundamental element in the characterization of the fire's fuel load in wildfire episodes. Satellite imagery and field surveys can help to estimate Fuel Moisture Content (FMC) in different environments. FMC is computed as wet weight over dry weight of vegetation samples. In this study, 24 FMC samples of Brazilian Savana vegetation were collected between May and October 2019 in two phytotypes: Cerrado Típico and Campo Limpo, in the municipality of Sacramento / MG. We applied an statistic correlation to reflectance of the Sentinel-2 MSI spectral bands (Multispectral Instrument). Data on soil moisture, temperature, precipitation and air humidity were tested in a Multiple Linear Regression to verify possible impacts of these elements on FMC results. SWIR 1 band had a better correlation (R² = 0.33) with Campo Limpo samples, the reflectance increases as the plant's humidity decreases, turning to dead leaves. In Cerrado Típico, FMC increased during the period, keeping leaves alive. Dead leaves are affected by atmospheric variations and are more prone to burning. The risk of fire is imminent in Campo Limpo and reflectance analysis of short wave infrared (SWIR) is a strategy to predict risk of fires in this environment.Keywords:  wildfire risk; fuel moisture content; reflectance

scholarly journals Computational and theoretical analysis of the fuel moisture influence on the fire-tube boiler unit efficiency at wood chips combustion

2021 ◽  
Vol 18 (2) ◽  
pp. 173-180
Author(s):  
V. A. Yakovlev ◽  
◽  
A. V. Osipov ◽  
Keyword(s):  
Theoretical Analysis ◽  
Moisture Content ◽  
Solid Fuel ◽  
Combustion Products ◽  
Wood Chips ◽  
Convective Heating ◽  
Fuel Moisture ◽  
Boiler Unit ◽  
Operating Modes ◽  
Fuel Moisture Content

The article presents the results of a computational and theoretical analysis of the performance of the solid fuel boiler unit intended for wood chips combustion, the input fuel moisture content being of 10% to 50%. The authors consider the main design features of the solid fuel boiler unit equipped with a shielded furnace and fire-tube two-pass convective heating surfaces without turbulent movement intensifiers of combustion products. The influence of changes in the moisture content and the operating modes of the boiler unit on the main balance and operating values responsible for the thermal efficiency and economy of the boiler is analyzed.

Predicting 1-H Dead Fuel Moisture Content at Regional Scales Using Machine Learning from Himawari-8 Data

2021 ◽  
Author(s):  
Chunquan Fan ◽  
Binbin He ◽  
Peng Kong ◽  
Hao Xu ◽  
Qiang Zhang ◽  
...  
Keyword(s):  
Machine Learning ◽  
Moisture Content ◽  
Fuel Moisture ◽  
Fuel Moisture Content

scholarly journals Evaluating the Effects of Projected Climate Change on Forest Fuel Moisture Content

2014 ◽  
Vol 37 ◽  
pp. 65-69
Author(s):  
Kellen Nelson ◽  
Daniel Tinker
Keyword(s):  
Climate Change ◽  
Moisture Content ◽  
Stand Structure ◽  
Canopy Cover ◽  
Fire Season ◽  
Climate Change Scenarios ◽  
Fuel Moisture ◽  
Mature Forest ◽  
Forest Fuel ◽  
Fuel Moisture Content

Understanding how live and dead forest fuel moisture content (FMC) varies with seasonal weather and stand structure will improve researchers’ and forest managers’ ability to predict the cumulative effects of weather on fuel drying during the fire season and help identify acute conditions that foster wildfire ignition and high rates of fire spread. No studies have investigated the efficacy of predicting FMC using mechanistic water budget models at daily time scales through the fire season nor have they investigated how FMC may vary across space. This study addresses these gaps by (1) validating a novel mechanistic live FMC model and (2) applying this model with an existing dead FMC model at three forest sites using five climate change scenarios to characterize how FMC changes through time and across space. Sites include post-fire 24-year old forest, mature forest with high canopy cover, and mature forest affected by the mountain pine beetle with moderate canopy cover. Climate scenarios include central tendency, warm/dry, warm/wet, hot/dry, and hot/wet.

Effects of distribution of bulk density and moisture content on shrub fires

2013 ◽  
Vol 22 (5) ◽  
pp. 625 ◽  
Author(s):  
Ambarish Dahale ◽  
Selina Ferguson ◽  
Babak Shotorban ◽  
Shankar Mahalingam
Keyword(s):  
Moisture Content ◽  
Spatial Variation ◽  
Bulk Density ◽  
Solid Fuel ◽  
Numerical Solutions ◽  
Propagation Speed ◽  
Fire Spread ◽  
Fuel Moisture ◽  
Combustion Heat ◽  
Fuel Moisture Content

Formulation of a physics-based model, capable of predicting fire spread through a single elevated crown-like shrub, is described in detail. Predictions from the model, obtained by numerical solutions to governing equations of fluid dynamics, combustion, heat transfer and thermal degradation of solid fuel, are found to be in fairly good agreement with experimental results. In this study we utilise the physics-based model to explore the importance of two parameters – the spatial variation of solid fuel bulk density and the solid fuel moisture content – on the burning of an isolated shrub in quiescent atmosphere. The results suggest that vertical fire spread rate within an isolated shrub and the time to initiate ignition within the crown are two global parameters significantly affected when the spatial variation of the bulk density or the variation of fuel moisture content is taken into account. The amount of fuel burnt is another parameter affected by varying fuel moisture content, especially in the cases of fire propagating through solid fuel with moisture content exceeding 40%. The specific mechanisms responsible for the reduction in propagation speed in the presence of higher bulk densities and moisture content are identified.

Modelling fine fuel moisture content and the likelihood of fire spread in blue gum (Eucalyptus globulus) litter

2014 ◽  
pp. 353-359
Author(s):  
Anita Pinto ◽  
Juncal Espinosa-Prieto ◽  
Carlos Rossa ◽  
Stuart Matthews ◽  
Carlos Loureiro ◽  
...  
Keyword(s):  
Moisture Content ◽  
Eucalyptus Globulus ◽  
Fire Spread ◽  
Fuel Moisture ◽  
Fuel Moisture Content ◽  
Blue Gum
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