• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.47-49
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• 2014

발전소에서 설계 규격을 벗어나는 저등급 석탄을 사용하기 시작하면서, 보일러에서의 연소특성을 예측하기 어려운 다양한 성질의 석탄이 들어오게 되어 각종 연소 문제가 증가하고 있다. 이 중 약 점결 특성을 가지는 저등급 석탄의 사용은 대형 클링커로 인한 보일러 하부의 튜브 손상 사고, 재열증기온도 상승으로 인한 출력감발 등의 문제를 발생시켰다. 또한 현재 개발 중인 무회분석탄 역시 점결 특성을 가지고 있는 것으로 알려져 있어 보일러 내부의 다양한 문제를 일으킬 것으로 예상되고 있다. 발전소에서는 강점결탄 수입 규제를 위해 CSN(Crucible Swelling Number)를 이용하여 제철용으로 사용되는 강점결 석탄의 도입을 규제해왔으나, 발전소 운영에 악 영향을 미치는 약 점결탄에 대한 규제 및 대응으로는 그 효과가 미미한 실정이다. 따라서 본 연구에서는 석탄의 점결 특성 중 팽창 특성을 분석할 수 있는 Microdilatometer와 TGA를 이용한 연소반응성 분석을 통해 석탄의 점결 특성이 연소반응성에 미치는 영향을 분석하였다.

• Journal of the Society of Disaster Information
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• v.13 no.3
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• pp.296-304
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• 2017

In order to predict about forest fire behavior we constructed a database for combustion characteristic of forest fuels in Samcheok, Gangwon-do and prepared fire risk map and fire risk rating using GIS method in this study. For the mapping autoignition temperature, ignition time, flame duration time, total heat release and total smoke release are selected as the standardized parameters and the overall risk rating was made up of the ignition risk parameters(autoignition temperature, ignition time) and the spread risk parameters(flame duration time, total heat release, total smoke release). Forest fire risk was classified into 5 grades and lower grade of fire risk rating mean to correspond to more dangerous forest fire. As a result, the overall risk rating of Samcheok was classified into three grades from 1 to 3 and Nogok-myeon and Miro-myeon were turned out the most dangerous areas for forest fire. Because of the colony of pine and oak trees and the higher fire loads, the flame propagation will be carried out quickly in these areas.

• Journal of the Society of Disaster Information
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• v.15 no.4
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• pp.531-539
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• 2019

Purpose: The purpose of this study is to present the commodity classification method of domestic rack-type warehouse for sprinkler system design. Method: On-site surveys and classification criteria of the NFPA, FMDS, EN and Japan were analysed and ISO 12949 test were carried out with proposed each classification commodity. Result: Based on a heat of combustion, a classification method for extra high, high, medium and low are proposed. Conclusion: Sprinkler design criteria to secure the maximum extinguishing strength for each class of commodity need to be applied.

• Journal of Energy Engineering
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• v.23 no.3
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• pp.211-220
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• 2014

This study reports the formation characteristics of tar, ash and clinker due to a wood pellet grade and the performance analysis of wood pellet boiler in terms of the moisture contents change of the wood pellet. Tar was accumulated on the heating surface according to combustion of wood pellet, the ash was yielded on the floor of combustion chamber in a wood pellet boiler and the clinker was solidified at the burner due to combustion of the 3rd grade wood pellet. Especially, the moisture contents is important factor to define the grade. Wood of logging residues has a non-uniform moisture contents after the field process, yields of tar, ash and clinker are increased in case of combustion due to the high ash contents. For these reasons, emission of harmful compounds in the exhaust gas, decrease of boiler efficiency and the system operating errors are observed. In the performance analysis of wood pellet boiler in terms of the moisture contents change of the 1st grade wood pellet, the boiler efficiency was reduced by 27.08% with 6.6% moisture contents increase. The optimum moisture contents of wood pellet is needed to improve the boiler performance and efficiency.

• 한국연소학회:학술대회논문집
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• 2000.05a
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• pp.45-56
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• 2000

미분탄 연소시 발생하는 질소산화물(NOx)은 석탄의 형태 및 등급에 따라 다르게 나타난다. 석탄에 함유되어 있는 질소 성분은 준역청탄인 경우 촤보다 휘발분에 많이 분포되어 있으며, 역청탄인 경우 촤에 많이 분포되어 있음을 확인하였다. 석탄에 함유되어 있는 질소의 분포에 따라 연속과정에 의해 최대로 발생할수 있는 질소산화물의 양과 질소산화물로 전환되는 정도를 예측할 수 있었다. NOx 방출은 석탄중에 함유되어 있는 질소성분의 양에 영향을 받으며, 고온 노출 시 방출되는 휘발성분의 양의 증가 그리고 공기비를 감소함으로서 질소산화물의 저감율을 증가시킬 수 있었다. 특히 질소산화물의 환원은 연료가 풍부한 조건에서 연소초기 고온으로 연소하는 경우 효과적이었다. 또한 2단 연소에 의한 방법으로 1단에서는 저공기비로 유지하고 2단에서 추가적인 공기를 공급함으로서 최종 공기비는 1.2인 조건에서 효과적으로 NOx를 저감할 수 있었다.

• Fire Science and Engineering
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• v.23 no.5
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• pp.66-71
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• 2009

In this study, I evaluated toxicity that analyze performance of flame-retardant about flame-retardant painting wood and combustion gas that is based on the toxicity index. Processing condition of flame retardant solution and treatment method of samples didn't affect greatly to performance of flame retardant. Occurrence of combustion gas showed a almost similar result from the sample which spraying flame retardant solution and toxicity corresponds to high level, Hazard Class III, and the flame retardant solution saturation sample which makes put out Hazard Class II which is a low toxicity relatively.

• Applied Chemistry for Engineering
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• v.34 no.4
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• pp.388-396
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• 2023

The evaluation of fire risk for combustible materials was carried out using Chung's equations-X, Chung's equations-XI, and Chung's equation-XII, which were newly established. The fire risk index-XII (FRI-XII) and fire risk rating (FRR) were calculated for specimens including camphor tree, cherry, rubber tree, and elm. The combustion characteristics were determined using a cone calorimeter according to ISO 5660-1. Chung's equations caculated the fire performance index-X (FPI-X) and fire growth index-X (FGI-X) values ranged from 89.34 to 1696.75 s² /kW and from 0.0006 to 0.0107 kW/s² , respectively. In addition, the fire performance index-XI (FPI-XI) and fire growth index-XI (FGI-XI) varied from 0.08 to 1.48 and from 0.67 to 11.89, respectively. The fire risk index-XII (FRI-XII), which is an indicator of fire risk, showed that camphor tree had a value of 148.63 (fire risk rating: G), indicating a very high fire risk. This suggests that combustible materials with a high concentration of volatile organic compounds have lower FPI-X and FPI-XI values, higher FGI-X and FGI-XI values, and consequently higher FRI-XII values, indicating an increased fire risk.

• Applied Chemistry for Engineering
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• v.34 no.2
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• pp.144-152
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• 2023

To evaluate the fire risk of combustible materials, Chung's equations VII, VIII, and IX were newly established. The fire risk index-IX (FRI-IX) and fire risk rating (FRR) were calculated. Ginkgo, dawn redwood, toona, lime, walnut, and polymethylmethacrylate (PMMA) were selected as test specimens. The combustion characteristics were evaluated using a cone calorimeter according to ISO 5660-1. After combustion, the fire performance index-VII (FPI-VII) of the specimens, varied between 15.15 and 182.53 s²/kW, as determined by Chung's equations, and the fire growth index-VII (FGI-VII) varied between 0.0023 and 0.0165 kW/s². The fire performance index-VIII (FPI-VIII) based on PMMA varied between 0.29 and 3.45, and the fire growth index-VIII (FGI-VIII) varied between 2.88 and 20.63. The FRI-IX, which is the fire risk rating, showed dawn redwood has a very high fire risk, with FRI-IX values of 71.14 (fire risk rating: G). Therefore, wood with a large amount of volatile organic compounds and a low bulk density showed a high value of FRI-IX by lowering FPI-VII and FPI-VIII and increasing FGI-VII and FGI-VIII.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.9
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• pp.945-951
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• 2012

A water emulsion fuel can be used to reduce soot and NOx emissions simultaneously because it has a lower combustion temperature and better fuel atomization owing to the evaporative latent heat and microexplosion of water. Moreover, it can be used without making special modifications to conventional diesel engines. Therefore, this fuel has attracted considerable research attention. In addition, lower-grade fuels are being considered for use in conventional engines because of an increase in oil prices. In this study, we investigated the combustion and exhaust characteristics of MDO (marine diesel oil), which has a lower grade than common diesel oil, and ME (MDO water emulsion) under various test conditions in an automotive diesel engine.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.4
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• pp.41-47
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• 2020

This study aims to develop eco-friendly propellant that reduce the generation of harmful gases such as HCl gas and increase the emmision of nitrogen gas emissions. For this purpose, GUDN(N-Guanylurea dinitramide) and BTATz(3,6-bis(1H-1,2,3,4-tetrazol-5-ylamino)-1,2,4,5-tetrazine), which are low carbon high nitrogen materials, were used instead of AP(Ammonium Perchlorate) and Al(Aluminium), which are gernerally used in solid propellant. The prepared propellants were analyzed for mechanical properties and combustion characteristics, performance and AGARD smoke classification. Compared with AP/Al propellant, GUDN/BTATz propellant tended to decrease mechanical and combustion rate. Also, as a result of the static test after the production of the 4-inch motor, the performance of combustion of the GUDN/BTATz propellant decreased, but it was confirmed that the secondary smoke was improved by reducing harmful gases such as HCl gas.