• 한국화재소방학회논문지
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• 제25권2호
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• pp.88-94
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• 2011

건축물 적재가연물의 연소성상 및 발열특성은 건물 내부의 화재전파속도와 화재규모 등을 크게 좌우하는 중요한 요인이다. 그러나 대형 서점의 적재가연물은 다른 건축용도에 비해 다량 적재되어 있기 때문에 화재시 건물 전체의 화재피해가 대형화할 가능성이 있지만 연소발열성상이 화재실험 등으로 파악되어 있지 않다. 따라서 본 연구는 대형서점의 적재가연물인 목재 서가 등을 재현한 시험체를 대상으로 연소실험을 실행하여 연소발열성상을 파악하였다. 또한 이 결과를 바탕으로 대형서점의 화재시 화재안전성을 검토하고 대형 서점의 화재안전설계에 필요한 적재가연물의 연소표면적당 최대열방출률과 화재성장률 등을 제시하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제28권7호
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• pp.1101-1110
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• 2004

An one-zone heat release analysis was applied to a 4 cylinder indirect injection diesel engine. The objective of the study is to calculate heat release accurately considering the effect of specific heat ratio. heat transfer and crevice model and to find out combustion characteristics of an indirect diesel engine considering the effect of the pressures in main and swirl chambers. Especially specific heat ratio indicating combustion characteristics is adapted. instead of that indicating matter properties, which has been used in former studies Moreover by adaption of blowby model, cylinder gas mass became accurately calculated. Therefore, with ideal gas equation, calculating cylinder gas temperature, it was found to affect heat transfer loss and heat release. Determining heat transfer constants $C_1$. $C_2$ as 0.6 respectively. the integrated gross heat release values were predicted well for the measured value at various engine speed, full load operating conditions. The curve of heat release rate was similar to SI engine rather than DI engine. That is originated from that swirl chamber reduce an instant combustion which occurs in DI engine due to ignition delay on early stage of combustion.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.206-212
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• 2009

Chemical behaviors of each surface material for interior facilities affect to fire initiation and growth in general fire situation. These chemical behaviors were characterized by thermal properties (Heat release rate, Pyrolysis rate, specific heat, etc) which could be derived from experimental test. Especially, Heat release rate which indicates aspect of fire size is one of the most important property to asses fire hazard and protection needs. The cone calorimeter test (ISO 5660) has recently assumed to a dominant role in bench scale fire testing to obtain the Heat release rate of materials. This value could be calculated by the 'Oxygen Consumption Method' under various producing irradiances to each surface of materials. In this study, Process of the cone calorimeter test was simulated by Pyrolysis model of FDS (Fire Dynamics Simulator by NIST) base on the ISO 5660 international standard. Then, we could estimate the simulation method of FDS in case of single materials through the comparative study with test results.

• 한국산학기술학회논문지
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• 제21권11호
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• pp.349-356
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• 2020

ISO 9705 룸코너 시험을 통해 복합소재 고체 가연물의 화재발생시 발생되는 열방출률을 측정하고 화재성장율을 계산하여 Fire Dynamics Simulator (FDS)에서 제공하는 열방출률 예측 모델을 사용자가 시험을 통해 얻어진 질량 소모율을 직접 입력하고 점화원에 의해 가연물의 표면 온도가 점화 온도에 도달하게 되면 정해진 연료를 소모하게 됨으로써 열방출률이 계산되는 단순 모델 (Simple model)과 질량 소모율을 직접 계산하는 방식으로 고체 가연물의 온도를 계산하고 고체 가연물의 열분해율을 조절하여 직접 열방출률을 계산하는 열분해 모델 (Pyrolysis model)로 구분하고 각각의 열방출률 모델에 필요한 입력 인자를 적용하여 동일한 조건에서 밀폐된 구획 환경에 따라 FDS 전산 해석을 수행하였다. 복합소재 고체 가연물로는 PU 폼과 PP, 철재로 대부분 구성되어있는 영화관 의자를 선정하였다. 동일한 조건에서 밀폐된 구획 환경에 따라 각각의 열방출률 예측 모델을 해석한 결과, 밀폐된 구획에서 단순 모델을 통해 예측된 열방출률과 화재성장율이 열분해 모델을 이용하는 경우에 비해 다소 과예측되는 것을 확인 할 수 있었다.

• Journal of Advanced Marine Engineering and Technology
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• 제30권5호
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• pp.572-579
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• 2006

Accurate heat release analysis based on the cylinder pressure trace is important for evaluating combustion process of diesel engines. However, traditional single-zone heat release models (SZM) have significant limitations due mainly to their simplified assumptions of uniform charge and homogeneity while neglecting local temperature distribution inside cylinder during combustion process. In this study, a heat release analysis based on single-zone model has been evaluated by comparison with computational simulation result using Fire-code, which is based on multidimensional model (MDM). The limitations of the single-zone assumption have been estimated, To overcome these limitations, an improved model that includes the effects of spatial non-uniformity has been applied. From this improved single-zone heat release model (Improved-SZM), two effective values of specific heat ratios, denoted by ${\gamma}_V$ and ${\gamma}_H$ in this study, have been introduced. These values are formulated as the function of charge temperature changing rate and overall equivalence ratio. Also, it is applied that each equation of ${\gamma}_V$ and ${\gamma}_H$ has respectively different slopes according to several meaningful periods during combustion progress. The heat release analysis results based on improved single-zone model gives a good agreement with FIRE-code results over the whole range of operating conditions of target engine, Hyundai HiMSEN H21/32.

• 대한기계학회논문집B
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• 제22권8호
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• pp.1183-1194
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• 1998

This paper describes a theoretical model developed for analyzing the heat transfer of automotive cooling systems. From the model, heat transfer rate of automotive cooling systems can be predicted, providing useful information at the early stages of the design and development. The aim of the study is to develop a simulation program for automotive cooling system analysis and a performance analysis program for analyzing heat exchanger. Heat release rate from combustion gas to coolant through cylinder wall in engine cylinder was analyzed by using a two zone combustion model. This paper studied how cooling condition would affect engine heat release rate and measured temperature distribution of coolant in water jacket.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2006년도 전기학술대회논문집
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• pp.41-42
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• 2006

A study on the combustion characteristics by using Emulsion Fuel in Diesel Engine is performed experimentally. In this paper, the experiments are performed at engine speed 1800rpm, emulsion fuel ratio is 0%, 10%, 20%, and main measured items are specific fuel consumption, pressure, ratio of pressure rise, rate of heat release etc. The obtained conclusions are as follows. 1) Specific fuel consumption increase maximum 19.8% at low load, but is not effected at full load. 2) Ratio of pressure rise and rate of heat release are about the same in the case of 10% and 20% of emulsion fuel ratio. 3) Cylinder Pressure increase 11.7%, ratio of pressure rise increase 60.4% in case of emulsion fuel ratio 20% at full load. 4) Rate of heat release increase 76.9% in case of emulsion fuel ratio 20% at full load.

• 한국연소학회지
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• 제22권4호
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• pp.1-8
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• 2017

This study was conducted to evaluate the fire retardant performance of exfoliated graphite nanoplatelets (xGnP) applied for particleboard. This work measured heat release rate(HRR), total heat release(THR) and smoke production rate(SPR) of xGnP added particleboard, using cone calorimeter to assess its fire characteristics according to the KS F ISO 5660-1 standard code. Heat release rates of all specimens treated by xGnP were less than the $200kW/m^2$ for a total experiment period of five minutes. Heat release rates of the specimens coated with xGnP were lower than those of the specimens made by mixing wood particles with xGnP directly. Meanwhile, the total heat release rates of xGnP coated specimen maintained quite lower level than the uncoated so the xGnP coating were effective in improving the fire retardant performance of particleboard. However, the smoke emission peaking problem at the initial combustion period, which was caused by adding base coating materials, should be resolved for further satisfaction as a fire retardant materials.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.609-613
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• 2008

The fire whirl occurring by the instability of atmosphere is a rare phenomenon, but highly destructive because it has high inhalation and lift force, caused by the rotating velocity. And it is difficult to extinguish the fire, because of increment of the spread rate with the flame height. In this study, for investigation of the flow characteristic of fire whirl for various heat release rate, numerical analysis is performed in same conditions with experiments, using the FDS which is developed at NIST. For validating of the numerical study, the results are compared with the experiment. The result shows that the relation between the characteristic length and the ratio of circulation versus the buoyancy force is $z_f$/D$^{\ast}$ = 0.304(${\Omega}/{\alpha}$)^2 - 1.334${\Omega}/{\alpha}$ + 5.516.

• 한국자동차공학회논문집
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• 제13권6호
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• pp.21-30
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• 2005

Heat release analysis is a very importent method in understanding the combustion phenomena inside an engine cylinder. In this study, one-zone heat release analysis was used with the mesured cylinder pressures of an IDI(indirect injection), a HSDI(high speed direct injection) and a SI(spark ignition) engine. It has benefits of simple equation, fast speed, reliability. The object of the study is to compare the combustion characteristics among an IDI, a HSDI and SI engine. Result of analysis, the maximum heat release rate of a HSDI is higher than an IDI because of long ignition delay period. The heat release curve of a IDI is more linear than an HSDI, so the combustion characteristics of a IDI is similiar to that of an SI engine. There is a suggestion here that the combustion efficiency of a HSDI is highest of that of all engines because of the smallest heat transfer loss of all engines.