• 한국가스학회지
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• 제25권6호
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• pp.35-44
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• 2021

반도체 공정 중 PR (Photo Resist) 공정은 여러 인화성 물질을 혼합하여 사용하는 공정으로, 공정 장비가 Clean Room 내 설치되어 인화성 물질이 누출되는 경우 질식, 화재, 폭발 사고로 이어질 위험성이 크므로, 물질 누출시 발생할 수 있는 사고에 대한 영향을 분석하고, 작업자들의 안전을 보장할 수 있는지 평가하는 것이 필요하다. 본 연구는 FLACS CFD - Fire Module을 이용하여 10개의 누출, 화재 시나리오에 대한 CFD Simulation을 통해 Clean Room 내부 가상으로 설정한 Monitor Point에서의 복사열 및 온도 변화 값을 확인하였다. Clean Room 내부에서 발생한 화재는 층간 구조물에 높은 복사열을 전달하지만, 그 범위가 상당히 제한적이며, 단일 화재 사고로 인해 붕괴될 가능성이 희박하다. 화재 사고로 인해 탈출구로 이어지는 2 곳의 계단이 동시에 높은 복사열에 노출되는 시나리오는 없어, 화재 발생시 작업자가 탈출 가능하였다. 또한 복사열 및 온도 상승의 수준은 아래층으로 이동하면서 급격하게 낮아지는 것을 확인하였으며, API 520의 기준에 따라 작업자가 30초 동안 버틸 수 있는 복사열인 6.31 kW/m²에 노출된 작업자도 화재가 발생한 Clean Room 내부에서 충분히 탈출할 수 있음을 확인하였다.

• 설비공학논문집
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• 제18권4호
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• pp.287-296
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• 2006

In this paper, optimal control strategy of the air-conditioning system with slab thermal storage was investigated based on the optimal control theory. An optimal heat output to the plenum chamber and the air-conditioned room was determined based on two kinds of criterion functions. The first one requires small deviation in room air temperature from a set-point value and low energy consumption. It is shown that the optimized control is to store heat through the whole storage time and to increase storage rate gradually with time. As the second case, a criterion that both a deviation of operative temperature from a set-point temperature and the energy consumption should be minimized was adopted. The room air temperature was a little high and the cooling load during storage time was reduced, compared with the results when a criterion function considering only the room air temperature is used.

• 한국의류학회지
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• 제21권7호
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• pp.1153-1161
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• 1997

The insulation provided by clothing system is usually expressed in terms of a coo units and its distribution of the body, directly affect convective, conductive, and radiant heat loss from the skin to the environment Evaporated heat loss is dependent upon fabric permeability, the amount of body surface area covered by clothing, and the pumping of air between the body and garment layers. Persons at low to medium activity levels, dressed in conventional apparel in door environments, usually do not lose a large amount of heat through evaporation. Thermal manikin technology is used to measure the resistance to heat transfer provided by clothing systems. The reciprocal of this value, 6.45 W/m2.$^{\circ}C$ is often used in calculations for convenience. The purpose of this study was to implement a research program for calculation the insulation value (clo), body surface area and basal metabolic rate of selected clothing system. The project provided for the building of an insulation data base for use in evaluating and comparing new and improved garments.

• 동력기계공학회지
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• 제21권3호
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• pp.30-36
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• 2017

Carbon fiber shows excellent heat generation value and thermal efficiency comparing with the metallic materials because of its far infrared-rays and radiant heat. So, high performance and economic steam boiler system for the industry can be manufactured by using the carbon fiber heater. The far infrared ray radiation rate was more than 90 % of carbon fiber. Steam boiler system with carbon fiber heater in this study is made up of heating section. In the proof test of steam boiler, the aimed temperature and dwelling time were at $500^{\circ}C$ for 8,000 hours, $600^{\circ}C$-3,000 hours, and $700^{\circ}C$-1,000 hours. The temperature rise rate of steam boiler with carbon fiber heater was about 40% faster than that of the conventional boiler.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.278-283
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• 2003

Analysis has been carried out to investigate the temperature variation and the uniformity of the temperature distribution of the glass panel by infrared radiant heating. Halogen lamps are used to heat the panel and located near the top and bottom of the rectangular chamber. The thermal energy is transfered only by radiation and the radiation exchange occurs only on the solid surfaces and is considered by using the view factor. The results show that the uniformity of the temperature distribution of the panel is improved but the time for heating increases as the wall reflectivity is large. The temperature difference reaches a maximum in the early stage of the heating process and then decreases until it reaches the uniform steady-state value.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1524-1529
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• 2003

We was made 150L an water storage electric boiler and obtained various performances of the storage, radiant and keeping by experimentation, The storage performance is that the heat were off about 50 minutes after heating start, Then the temperature of outlet was arrived the stead state at $91^{\circ}C$ and the storage performances was appeared 93.64%, In the radiant performance, the water temperature was decreased from $90^{\circ}C$ to $44.8^{\circ}C$ after 960 minutes, Then the calorific value changed from 675kcal/h to 72kcal/h and the temperature decreased about 50%, The keeping performance showed mean temperature, $67.06^{\circ}C$ according to progress 800 minutes and the maximum temperature drop were $0.2^{\circ}C$, By the results of the performance valuation, the water storage electric boiler was verified fitted quality on the test prescription of KERI(Korea Electrotechnology Research Institute).

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2010년도 학술발표회
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• pp.91-100
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• 2010

To investigate the thermal properties of a water-retentive artificial turf system (W-ATS), we estimated hydrologic parameters including thermal conductivity, heat capacity, and surface albedo for both the W-ATS and natural grass. We used a model experiment to measure surface temperature and evaporation for both the W-ATS and natural grass. We found that the W-ATS had lower thermal conductivity than natural grass did, and it was difficult for the W-ATS to convey radiant heat to the ground. Compared to natural grass, the W-ATS also had lower heat capacity, which contributed to its larger variation in surface temperature: the W-ATS had higher surface temperatures during daytime and lower surface temperatures during nighttime. The albedo of the W-ATS was one-quarter that of natural grass, and reflected shortwave radiation from the W-ATS surface was lower than that from the surface of natural grass. These results indicate that the W-ATS caused the soil temperature to increase. Furthermore, evaporation from the W-ATS was one-quarter the value of evapotranspiration from natural grass.

• 한국방재학회 논문집
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• 제10권5호
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• pp.75-82
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• 2010

본 연구에서는 화재강도에 따른 산림연료의 연소특성을 고찰하기 위하여 산불에 가장 취약한 소나무 생엽을 대상으로 복사열을 변수(25 kW/$m^2$, 50 kW/$m^2$, 75 kW/$m^2$)로 하여 연소특성 실험을 수행하였다. 콘칼로리미터 장비를 이용하여 착화특성, 발열 특성, 발연량 및 CO, $CO_2$ 방출특성, 중량감소특성 등을 분석하였다. 60.66% 수분을 함유한 소나무 생엽은 25 kW/$m^2$, 50 kW/$m^2$, 75 kW/$m^2$ 복사열에서 착화가 일어나지 않았으며, 복사열 크기가 클수록 발열량과 열방출율은 2배 빠른 시간에 급격하게 최대값에 도달하고 최대값은 2배 정도 높은 것으로 나타났다. 발연량은 복사열 크기가 작을수록 불완전 연소로 인한 연기방출량은 많은 것으로 나타났다. CO 및 $CO_2$ 방출량은 복사열이 증가할수록 최대값이 급격히 높고, 빠른 시간에 최대값에 도달하는 것으로 나타나 복사열이 증가할수록 탄소산화물은 많은 것으로 나타나 산불발생 시 대형산불의 경우 많은 양의 CO와 $CO_2$를 방출할 것으로 사료된다.

• 한국태양에너지학회 논문집
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• 제28권3호
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• pp.35-44
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• 2008

In this study, the experiment of the measuring of four different types of flooring materials' thermal characteristics was conducted and examined during the summer. The experimental materials were arranged on the existing slab of the roof, and then its thermal characteristics were examined from the point of view of thermal radiation analysis. The aim of this study is ultimately to draw the fundamental data for improvements in a building's thermal function and reduce the urban heat island phenomena through optimizing the thermal characteristics of the surface covering materials of a building. The results from this study are as follows; 1) Each experimental material's albedo was calculated as 0.83 on the aluminum panel, 0.40 on the rock block, 0.37 on the wood deck and 0.21 on the concrete. It shows that the concrete material, which has the lowest short wave reflective rate, absorbed the most radiation energy and the aluminium panel has absorbed the lowest radiation energy. 2) From the each experimental object's value of the long wave radiation, the concrete material measured the highest, at $628W/m^2$, and the aluminium panel measured the lowest at $412W/m^2$. Therefore, it verifies that the experimental objects' own radiation rate determines the amount of the long wave radiation. 3) The degree of energy absorbency of a building's surface covering materials is greatly influenced by its own albedo and radiation rate, Therefore, it needs to be considered for the improvements in a building's thermal function and reducing the urban heat island phenomena. 4) According to the evaluation result of the each experimental object's overall heat transmission screening function on the roof of a building, the wooden deck is proven to be an excellent material for excluding the outside temperature differences effectively with its characteristic of low heat capacity and conduction. Also its surface temperature on the roof slab and the temperature difference during the day were both measured at low.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.157-159
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• 2014

This article describes an investigation of basic combustion characteristics of radiant burner with various firing rate and equivalence ratios in porous metal. As a main experimental condition, firing rates and equivalence ratios each were adjusted from 204 to $408kW/m^2$ and 0.6 to 1.3. The purpose of this study is to investigate radiation efficiency using two experiment methods. The first way is to calculate the radiation efficiency by measuring the temperature of the burner surface, and the second is to compute the radiation efficiency by measuring the radiation intensity of the burner surface with a radio meter. The value of the radiation efficiency did not exactly match in the two cases. But we figured out that in accordance with increasing heat power, radiation efficiency was decreased. And additional complementary experiment on the relationship between these values is needed.