• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.648-651
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• 2009

탄소섬유강화플라스틱(CFRP:Carbon Fiber Reinforced Plastic)용기의 외부에 화재가 발생할 경우 함침된 수지(Resin)가 탄화되면서 자체 강도가 약화되고 충전된 가스가 외부 온도 상승에 따라 압력 상승이 발생하여 용기의 폭발로 이어지는 사고가 발생할 개연성이 높다. 화염 노출조건에서 복합재료 용기의 폭발을 방지하기 위하여 용기용 밸브에 내장된 온도감응식 압력안전장치(TPRD:Thermally activated Pressure Relief Device) 작동 성능을 검증하기 위한 방법으로 화염실험(Bonfire test)를 실시하고 있으나, 개방 공간에서 실시되는 이 실험은 표면 온도 변화가 매우 크게 발생하여 실험에 대한 재현성(Reproducibility)에 의문이 제기되고 있다. 따라서, 표면 온도를 일정하게 유지하기 위한 실험 방법의 개선이 필요하다. 본 연구에서는 경유+heptane을 이용한 전체 화염에 노출되는 경우와, 천연가스를 이용한 단일화염에 노출되는 경우의 실험 결과 비교를 통하여 화염 노출 표면 온도를 일정하게 유지하기 위한 가열 방법의 타당성을 검토하였다. 또한, 복합재료 라이너(Liner)의 온도 변화 비교를 통하여 집중화염 노출 조건에서 열전달 특성을 알아보았다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2009년도 추계 학술논문 발표대회
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• pp.93-96
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• 2009

The objective of this study is to analyze the insulation characteristics of the polylon hybrid fiber inserted high-strength RC beam and slab produced as a single body and the results of this study can be summarized as follows. In the spalling mechanism as an insulation characteristic, the slab of the single body type specimen shows an exposure in concrete covers at the center of slab and that leads to the spalling, which exposures reinforcing bars. In the case of the beam, the spalling was presented at several sections as a type of peel spalling before and after 10 minutes from the insulation test. Whereas, although the internal temperature history of concrete represents the highest range as 581℃ in the case of the center of the bottom of beam base, it can be considered that it satisfies the regulation of insulation certification.

• 콘크리트학회논문집
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• 제20권3호
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• pp.325-333
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• 2008

본 연구에서는 강섬유와 서로 다른 직경 및 길이를 가진 폴리프로필렌섬유를 혼합한 하이브리드 섬유보강 콘크리트의 압축강도, 수축균열 및 고온에서 화재저항성을 평가하였다. 압축강도, 쪼갬인장강도, 휨시험 및 수축균열저항성을 평가하기 위하여 실시하였으며 또한 400$^{\circ}C$, 600$^{\circ}C$, 800$^{\circ}C$ 및 1,200$^{\circ}C$에 노출 후 물리 역학정 특성을 평가하기 위하여 표면관찰, 질량손실 및 잔류압축강도 시험을 실시하였다. 시험 결과 하이브리드 섬유보강 콘크리트는 역학적 성능, 수축균열저항성 및 화재저항성을 향상시켰으며 온도 변화에 따른 콘크리트의 성능 저하는 온도가 $600\sim800^{\circ}C$의 범위일 때 가장 컸다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.436-437
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• 2006

Porcelain insulators have generally been used in Korea but polymer insulators which are superior in that they are light weight, explosion proof, impact proof, economical with construction characteristics, have been in use for the 154kV transmission line since 1999 following a worldwide trend towards the reduced weight, simplification and compact usage of new material insulators. However there have been approximately 500 cases of forest fires in Korea, so the transmission lines that for the most part pass through mountainous areas have been highly effected and the highly polymerized compound polymer insulator has raised concern about reliability in cases of exposure to forest fires. Therefore for the reliability assessment of the effect of forest fires on polymer insulators, mechanical and electrical characteristics are analyzed by an artificial flare test device and transmission facility surrounding conditions along with forest fire characteristics are surveyed. In addition to this, actual 90kV energized transmission line was tested with an artificial forest fire and the expanded usage of polymer insulators is presented through the analysis of mechanical and electrical characteristics and physical properties, and a study on the influence of forest fires on polymer insulators.

• 한국화재소방학회논문지
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• 제28권4호
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• pp.97-103
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• 2014

소방보호복은 고열유속에 의한 화상방지를 위해 3층 이상의 복합소재로 구성되어 있으며, 각 소재 사이는 공기 간극이 존재한다. 화재에 의한 고열유속 노출 시 공기 간극 내에서의 열전달은 대류와 복사에 의해 주로 발생하며, 그로 인해 간극의 크기에 따라서 비선형 특징의 열 저항 크기를 갖게 된다. 그러므로 본 연구에서는 보호복 소재 사이의 여러 가지 공기 간극(0~7 mm)에 대한 보호복의 열 보호성능을 자세히 파악하기 위한 실험을 수행하였다. 복사 열 유속 입사시에 시간에 따른 각 소재의 온도 변화뿐만 아니라, 열 보호성능을 가장 효과적으로 나타낼 수 있는 지표(Radiant Protective Performance, RPP) 값의 공기간극에 대한 변화 특성을 파악하였다. 공기간극이 증가할수록 단열효과가 커짐으로 인해 후면의 온도는 낮아지고, RPP는 커짐을 확인할 수 있었다. 특히 일정 열유속 조건에서 공기간극에 대한 RPP 값은 선형적인 특성을 나타내었고, 그러한 결과를 바탕으로 다양한 입사 열유속 및 공기 간극 조건에 대해 비교적 간단한 형태의 RPP 지표 예측 식을 제안하였고, 좋은 예측 결과를 얻을 수 있었다.

• International Journal of Concrete Structures and Materials
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• 제10권sup3호
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• pp.19-31
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• 2016

The objective of this paper is to investigate the effect of thickness and moisture on temperature distributions of reinforced concrete walls under fire conditions. Toward this goal, the first three wall specimens having different thicknesses are heated for 2 h according to ISO standard heating curve and the temperature distribution through the wall thickness is measured. Since the thermal behavior of the tested walls is influenced by thickness, as well as moisture content, three additional walls are prepared and preheated to reduce moisture content and then tested under fire exposure. The experimental results clearly show the temperatures measured close to the fire exposed surface of the thickest wall with 250 mm thickness is the highest in the temperatures measured at the same location of the thinner wall with 150 mm thickness because of the moisture clog that is formed inside the wall with 250 mm of thickness. This prevents heat being transferred to the opposite side of the heated surface. This is also confirmed by the thermal behavior of the preheated walls, showing that the temperature is well distributed in the preheated walls as compared to that in non-preheated walls. Finite element models including moisture clog zone are generated to simulate fire tests with consideration of moisture clog effect. The temperature distributions of the models predicted from the transient heat analyses are compared with experimental results and show good agreements. In addition, parametric studies are performed with various moisture contents in order to investigate effect of moisture contents on the thermal behaviors of the concrete walls.

• 한국수소및신에너지학회논문집
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• 제35권3호
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• pp.310-317
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• 2024

In this study, Aimed to develop technology to ensure the safety of firefighters responding to hydrogen incidents and to review the performance of protective super absorbent polymer (SAP) that could help maintain the thermal protection performance of equipment with protective properties. Tests were conducted, including bench-scale and full-scale thermal exposure tests, to review the protective performance of SAP using firefighting garments commonly used by firefighters. The results showed that without SAP application, 2nd degree burn areas were measured at 9.4%, and 3rd degree burn areas at 7.7%. In contrast, when SAP was applied, the percentage of 2nd degree burn areas decreased to 7% on the lower body, and there was no temperature rise causing 3rd degree burns. Therefore, it is expected that by applying SAP to the outer surface of firefighter garments, even under temporarily high temperature conditions such as hydrogen jet flames, thermal damage to firefighters could be protected for a certain period.

• 대한임상독성학회지
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• 제18권1호
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• pp.34-41
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• 2020

Purpose: This study evaluated aggressive hyperbaric oxygen therapy (HBOT) by understanding various exposure routes of acute carbon monoxide (CO) poisoning, the risk factors causing acute cardiovascular, and neurological toxicity caused by poisoning. Methods: A retrospective study was conducted based on the medical records of 417 acute CO poisoning patients who visited the emergency care unit from March 2017 to August 2019. The exposure routes, HBOT performance, age, sex, medical history (hypertension, diabetes mellitus, ischemic heart disease, heart failure), intentionality, loss of consciousness (LOC), intake with alcohol or sedatives, and initial test results (carboxyhemoglobin (COHb), troponin-I, electrocardiography, echocardiography, brain MRI) were examined. Comparative analysis of the clinical information was conducted between the groups that showed acute cardiovascular toxicity and neurological toxicity, and groups that did not. Results: Among 417 patients diagnosed with acute CO poisoning, 201 cases (48.2%) were intentional, and charcoal briquette was the most common route (169 patients (40.5%)). Two hundred sixteen cases (51.8%) were accidental, and fire was the most common route (135 patients (32.4%)). The exposure route was more diverse with accidental poisoning. Three hundred ninety-nine patients were studied for acute cardiovascular toxicity, and 62 patients (15.5%) were confirmed to be positive. The result was statistically significant in intentionality, LOC, combined sedatives, initial COHb, HTN, and IHD. One hundred two patients were studied for acute neurological toxicity, which was observed in 26 patients (25.5%). The result was statistically significant in age and LOC. Conclusion: Active HBOT should be performed to minimize damage to the major organs by identifying the various exposure routes of CO poisoning, risk factors for acute cardiovascular toxicity (intentionality, LOC, combined sedatives, initial COHb, HTN, IHD), and the risk factors for acute neurological toxicity (age, LOC).

• 조명전기설비학회논문지
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• 제19권2호
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• pp.138-144
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• 2005

본 논문에서는 산불이 송전용 폴리머애자에 미치는 영향을 연구하기 위해 인공화염 시험장치를 제작하여 화염의 가열 시간에 따른 폴리머애자의 갓(shed) 변화와 자기애자의 disc 변화를 관찰하고, 전기적$\cdot$기계적 실험을 통하여 특성변화를 확인하였다. 실험결과 다음과 같은 결론을 얻을 수 있었다. 첫째, 화염의 가열시간이 5분정도 경과하였을 때, 자기애자의 전기적 특성은 $80(\%)$ 정도 저하된 반면에 폴리머애자의 경우 갓 유실이 있었지만 전기적 특성의 변화는 $10(\%)$ 정도였다. 폴리머애자를 20분 가열하였을 때는 대부분의 갓이 유실되었지만 전기적 특성치는 $20(\%)$ 정도 감소하였다. 둘째, 폴리머애자와 자기애자 모두 전기적 특성치의 감소는 있었지만 기계적 특성치는 양호하게 나타났다.

• Steel and Composite Structures
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• 제44권3호
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• pp.309-324
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• 2022

The post-fire elastic stiffness and performance of concrete-filled steel tube (CFST) columns containing recycled aggregate concrete (RAC) has rarely been addressed, particularly in terms of material properties. This study was conducted with the aim of assessing the modulus of elasticity of recycled aggregate concrete-filled steel tube (RACFST) stub columns following thermal loading. The test data were employed to model and assess the elastic modulus of circular RACFST stub columns subjected to axial loading after exposure to elevated temperatures. The length/diameter ratio of the specimens was less than three to prevent the sensitivity of overall buckling for the stub columns. The gene expression programming (GEP) method was employed for the model development. The GEP model was derived based on a comprehensive experimental database of heated and non-heated RACFST stub columns that have been properly gathered from the open literature. In this study, by using specifications of 149 specimens, the variables were the steel section ratio, applied temperature, yielding strength of steel, compressive strength of plain concrete, and elastic modulus of steel tube and concrete core (RAC). Moreover, parametric and sensitivity analyses were also performed to determine the contribution of different effective parameters to the post-fire elastic modulus. Additionally, comparisons and verification of the effectiveness of the proposed model were made between the values obtained from the GEP model and the formulas proposed by different researchers. Through the analyses and comparisons of the developed model against formulas available in the literature, the acceptable accuracy of the model for predicting the post-fire modulus of elasticity of circular RACFST stub columns was seen.