• Journal of Forest and Environmental Science
• /
• 제39권4호
• /
• pp.235-245
• /
• 2023

Forest fuel moisture content is a crucial factor influencing the combustion rate and fuel consumption during forest fires, significantly impacting the occurrence and spread of wildfires. In this study, meteorological data were gathered using a meteorological measuring device (HOBO data logger) installed in the south and north slopes of Kangwon National University Forest, as well as on bare land outside the forest, from November 1, 2021, to October 31, 2022. The objective was to analyze the relationship between meteorological data and fuel moisture content. Fuel moisture content from the ground cover on the south and north slopes was collected. Fallen leaves on the ground were utilized, with a focus on broad-leaved trees (Prunus serrulata, Quercus dentata, Quercus mongolica, and Castanea crenata) and coniferous trees (Pinus densiflora and Pinus koraiensis), categorized by species. Additionally, correlation analysis with fuel moisture content was conducted using temperature (average, maximum, and minimum), humidity (average, minimum), illuminance (average, maximum, and minimum), and wind speed (average, maximum, and minimum) data collected by meteorological measuring devices in the study area. The results indicated a significant correlation between meteorological factors such as temperature, humidity, illuminance, and wind speed, and the moisture content of fuels. Notably, exceptions were observed for the moisture content of the on the north slope and that of the ground cover of Prunus serrulata and Castanea crenata.

• 대한원격탐사학회지
• /
• 제23권1호
• /
• pp.21-32
• /
• 2007

Fire fuel map is one of the most critical factors for planning and managing the fire hazard and risk. However, fuel mapping is extremely difficult because fuel properties vary at spatial scales, change depending on the seasonal situations and are affected by the surrounding environment. Remote sensing has potential to reduce the uncertainty in mapping fuels and offers the best approach for improving our abilities. Especially, Hyperspectral sensor have a great potential for mapping vegetation properties because of their high spectral resolution. The objective of this paper is to evaluate the potential of mapping fuel properties using Hyperion hyperspectral remote sensing data acquired in April, 2002. Fuel properties are divided into four broad categories: 1) fuel moisture, 2) fuel green live biomass, 3) fuel condition and 4) fuel types. Fuel moisture and fuel green biomass were assessed using canopy moisture, derived from the expression of liquid water in the reflectance spectrum of plants. Fuel condition was assessed using endmember fractions from spectral mixture analysis (SMA). Fuel types were classified by fuel models based on the results of SMA. Although Hyperion imagery included a lot of sensor noise and poor performance in liquid water band, the overall results showed that Hyperion imagery have good potential for wildfire fuel mapping.

• 한국화재소방학회:학술대회논문집
• /
• 한국화재소방학회 2008년도 춘계학술논문발표회 논문집
• /
• pp.333-336
• /
• 2008

This study is the result between the variation of fuel moisture and the risk of forest fire through measuring the change of moisture containing ratio on-site and its average analysis for each diameter of surface dead fuels in the forest. The measurement was performed on six days from the day after a rainfall. The fuel moisture on-site was measured on the day when the accumulated rainfall was above 5.0mm, and the measurements was 2 times in spring. From the pine forest which were distributed around Samcheok and Donghae in Kangwondo, three regions were selected by loose, medium, and dense forest density, and the fuel moisture was measured on the ranges which are less than 0.6cm, 0.6-3.0cm, 3.0-6.0cm, and more than 6.0cm in the forest for six days from the day after a rainfall. The study showed that the moisture containing ratio converged on 3 - 4 days for surface deads fuels which diameter are less than 3.0cm and the convergence was made more than six days for ones which diameters are more than 3.0cm except the surface dead fuel of 3.0-6.0cm diameter of loose forest density.

• 한국방재학회:학술대회논문집
• /
• 한국방재학회 2008년도 정기총회 및 학술발표대회
• /
• pp.149-152
• /
• 2008

This study is the result between the variation of fuel moisture and the risk of forest fire through measuring the change of moisture containing ratio on-site and its average analysis for fallen leaves layer, humus layer, and soil layer in the forest. The measurement was performed on six days from the day after a rainfall. The fuel moisture on-site was measured on the day when the accumulated rainfall was above 5.0mm, and the measurements was 2 times in spring and 1 time in fall. From the pine forest which were distributed around Samcheok and Donghae in Kangwondo, three regions were selected by loose, medium, and dense forest density, and the fuel moisture was measured on fallen leaves layer, humus layer, and soil layer in the forest. for six days from the day after a rainfall. The study showed that the moisture containing ratio converged on 3 - 4 days in spring and fall for fallen leaves layer, and the convergence was made more than six days in spring and fall for the humus layer. In the other case of soil layer, the variation of moisture containing ratio after rainfall was not distinguishable regardless of season.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 1999년도 제19회 KOSCO SYMPOSIUM 논문집
• /
• pp.81-91
• /
• 1999

Fuel characteristics of sewage sludge as required for the fluidized bed incinerators have been evaluated. Sewage sludge is basically a solid fuel with high percentage of moisture. Moisture content of the fuel directly affects the heating value of the fuel and the exhaust gas composition. When the sludge of transported into the incinerator, sludge cake is subject to the mixing, break-up and heat-up. Fluidization process would enhance these physical processes. The sludge fuel could then undergo the moisture evaporation and devolatilization process. Subsequent oxidation of volatiles as well as the remaining char would then follow. Sludge samples are characterized with high percentage of volatiles out of total combustibles. Quantitative understanding of above listed subprocesses would certainly help in the utilization of fluidized bed incinerators. A limited set of fuel characterization tests including calorimetric analysis, proximate analysis, elemental analysis and thermogravimetric analysis were conducted for the selected sludge samples. The measurement reasults of sludge samples were reported along with some published data. Limited experience in the actual incinerator plant is also presented.

• 한국화재소방학회논문지
• /
• 제26권1호
• /
• pp.49-60
• /
• 2012

강우 후 경과일수에 따른 연료습도 변화는 산불위험도 예측과 산불감시원 활용에 매우 중요하다. 따라서 이러한 산불발생위험 조건을 구명하기 위해 2008, 2009년 봄 가을철 영동지역 활엽수림에서 임분 밀도별로 5.0 mm 이상 강우 후 낙엽층, 부식층, 토양층, 직경별 지표연료 0.6 cm 이하, 0.6~3.0 cm, 3.0~6.0 cm, 6.0 cm 이상에 대한 산불위험도를 분석하였다. 연구결과 봄철 낙엽층의 소임분 지역은 강우 3일 후부터, 중 밀임분 지역은 5일 후부터 산불발생 위험수준인 17 % 정도의 연료 습도를 나타냈다. 반면, 부식층은 계절에 상관없이 6일이 경과 되어도 40 % 이상의 연료 습도를 나타냈으나, 토양 상 하층은 미비한 변화가 있었다. 봄철 직경별 지표연료 0.6 cm 이하의 소임분 지역은 강우 3일 후부터, 중 밀임분 지역은 4일후부터 산불발생 위험수준 연료습도를 나타냈고, 가을철 직경별 지표연료 0.6~3.0 cm의 소임분 지역은 강우 3일 후부터, 중 밀임분 지역은 5일 후부터 산불발생 위험수준의 연료습도를 나타냈다. 봄 가을철 직경별 지표연료 3.0~6.0 cm의 경우 6일차가 되어도 소, 중, 밀임분 공히 높은 연료습도를 유지하고 있어 산불위험성은 매우 적은 것으로 조사되었으며, 6.0 cm 이상의 경우 계절에 상관없이 6일이 경과되어도 25 % 이상의 연료 습도를 나타냈다.

• 한국연소학회지
• /
• 제13권2호
• /
• pp.23-32
• /
• 2008

Gasification characteristics in the fluidized bed reactor are essential for the design of a gasification furnace to optimize the operation condition. Moisture content of the solid fuel is one of the important factors to influence directly the gasification characteristics. So it is necessary to investigate the effect of moisture content of solid fuel in partial oxidation condition. Gasification characteristics are investigated with results from thermogravimetric analyzer and lab-scale fluidized bed reactor for wood and RDF samples along with changing moisture contents. Additionally lab-scale fluidized bed reactor was run continuously and gas concentrations at the exit were measured. It is observed that the rate of reaction in partial oxidation condition is between the results from the combustion environment and from the inert condition. Moisture content in a particle slows down the heating rate of a particle. So, reaction is delayed by the moisture content. However, RDF samples those are easy to break-up don't show the effect of moisture content. The result of continuous operation condition shows that proper moisture content promotes gasification because steam from the particles helps gasification of the solid fuel. A simulation to predict the syn-gas composition was conducted by the Aspen Plus process simulator. The cold gas efficiency of the experiment was compared with results from the simulation.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2007년도 제34회 KOSCO SYMPOSIUM 논문집
• /
• pp.161-167
• /
• 2007

Gasification characteristics in the fluidized bed reactor are essential for the design of a gasification furnace to optimize the operation condition. Moisture content of the solid fuel is one of the important factors to influence directly the gasification characteristics. So it is necessary to investigate the effect of moisture content of solid fuel in gasification process. Gasification characteristics are investigated with results from thermogravimetric analyser and lab-scale fluidized bed reactor for wood and RDF samples along with changing moisture contents. Additionally lab-scale fluidized bed reactor was run continuously and gas concentrations at the exit were measured. It is observed that the rate of reaction in partial oxidation condition is in between the results from the combustion environment and from the inert condition. Moisture content in a particle slows down the heating rate of a particle. So, reaction time is delayed by the moisture content. However, RDF samples that are easy to break-up doesn't show the effect of moisture content. The results of continuous operation condition shows that proper moisture content promotes gasification because steam from the particles helps gasifcation of the sold fuel.

• 한국화재소방학회논문지
• /
• 제24권4호
• /
• pp.18-26
• /
• 2010

강우 후 경과일수에 따른 연료습도 변화는 산불위험도 예측과 산불감시원 활용에 매우 중요하다. 따라서 이러한 산불위험 조건을 구명하기 위해 2007년 봄철 영동지방 소나무림에서 임분 밀도별로 5mm 이상 강우 후 지표에 떨어져 있는 고사한 나뭇가지의 직경이 0.6cm 이하, 0.6~3.0cm, 3.0~6.0cm, 6.0cm 이상에 대한 연료습도변화 예측모델을 개발하였다. 연구결과 지표연료의 직경이 작고, 소임분일수록 연료습도의 감소가 빠르게 진행되었으며 산불위험 연료습도에 도달하는 날짜도 소임분 직경 0.6cm 이하의 경우 2일차, 직경 0.6~3.0cm의 경우 3일차로 나타났다. 이러한 결과를 토대로 각 직경별 연료습도변화 예측모델($R^2=0.76{\sim}0.92$)을 개발하였으며, 2008년 동일기간의 강우 후 기상 실측자료를 적용하여 예측모델을 검증한 결과 1% 수준에서 유의성이 있음을 알 수 있었다.

• 한국연소학회지
• /
• 제14권3호
• /
• pp.16-23
• /
• 2009

It is strongly desired for coal-fired power plants to utilize not only low-rank coals with high moisture contents, but also lowering cost with diversifying fuel sources. In this study, combustion characteristics of low rank coal with high moisture, and standard pulverized coals are experimentally investigated using TGA (Thermogravimetric Analysis) and DTF (drop tube furnace). The coals tested are three kinds of coal with moisture content ranging from 8.32 to 26.82%. The results show that under the air combustion condition, the burn-out time at TGA rises as moisture content increases, and standard pulverized coal with 8.32% moisture content showed the lowest activation energy of 55.73 kJ/mol. In case of the high amount of moisture, the combustion efficiency decreases due to evaporation heat loss, and unburned carbon in ash produced at combustion process in DTF increased. Aslo, initial deformation temperature of slag attached in alumina tube of DTF decreased with lowering the crytallinity of anorthite and augite. To improve the combustion reactivity and efficiency, it is effective to upgrade through drying the high moisture coal to moisture level (less than 10%) of standard pulverized coal.