汚染物質 放出量 측정챔버 製作 및 輕量칸막이벽의 VOCs 放出特性

방승기(Seung-Ki Pang),손장열(Jang-Yeol Sohn),백용규(Yong-Kyu Baik),조현(Hyun Cho) 한국생활환경학회 2004 한국생활환경학회지 Vol.11 No.1

In this research, the purpose was to understand the emission characteristics of VOCs from lightweight panel in different experimental condition, in order to compare and evaluate VOCs emitting from indoor construction materials in buildings. (l) First of all, we analyzed the problems related to the present measurement systems for VOCs, made a new measurement system, and verified the performance of the system. (2) With the new measurement system, we evaluated the emission rate of VOCs which is the basic material composing lightweight panel. (3) After we made various types of lightweight panel using the materials selected in process (2), we compared and evaluated the emission rate of VOCs in different temperature (20℃, 28℃), relative humidity (40%, 60%), and air exchange rate (0.5 time/h, 0.7 time/h) condition. We acquired the following conclusion as a result of the experiment. In case of constant temperature and relative humidity condition, the emission rate of VOCs from general oil paint was 250 times higher than that from vegetable water paint. As air exchange rate, temperature, and relative humidity rose, the emission rate of VOCs rose simultaneously. In case of the experiment of lightweight panel, the emission rate of Type Ⅰ composed of general paint and general adhesive was higher than that of Type Ⅱ, Ⅲ, Ⅳ. Therefore, it would be well-advised to use vegetable paint, vegetable adhesive, and general water paint for the improvement of Indoor Air Quality.

EMP 차폐를 위한 비상발전기 연도의 최적 형상 결정

방승기(Seung-Ki Pang),김재훈(Jae-Hun Kim) 한국에너지학회 2015 에너지공학 Vol.24 No.4

어린이 전용병원의 열원설비 대안별 Life Cycle Cost 분석

방승기(Seung-Ki Pang),채영태(Young-Tae Chae),이철구(Chul-goo Lee) 한국생활환경학회 2006 한국생활환경학회지 Vol.13 No.1

By increasing energy resource cost, the annual energy consumption for a HVAC has been an important factor as well as an initial cost of mechanic system to select a primary plant system. Hence, Life Cycle Cost (LCC) analysis is inevitable and needs to evaluate the efficiency of plant system. In this study, an economical efficiency of various plant system was validated to present the optimized plant solution for the new hospital for children. An annual HVAC energy consumption was calculated by energy simulation program (DOE 2.lE) and an economic efficiency of each plant system evaluated by LCC analysis method. The essential conclusions of this study are as follows; I) Because of many specific rooms which need 24 hour HAVC, energy consumption per area of the design building is higher than other buildings, 2) A totally hot and chilled water generator (HCWG) system (ALT-I) is the most profitable system in the point of initial cost, However 3) Considering a annual gross energy bill, which is fluctuated by energy source type and a initial cost of system, a composit system (ALT-2), a coupled system by an ice storage system and a HCWG system, is more effective than other systems during system life cycle, 4) A totally absorption system (ALT-3) has no merits of installing the plant system in the point of initial and running cost. Consequently, it is revealed that a composit system (ALT-2) is the most economical plant system for the new constructed building.

수치해석을 이용한 바닥공조 시스템의 공기환경 평가

방승기(Seung-Ki Pang),안혜린(Hye-Rin Ahn),이원근(Won-Keun Lee),문기선(Ki-Sun Moon),김종률(Jongryul Kim),이광호(Kwang-ho Lee) 한국지열·수열에너지학회 2016 한국지열에너지학회논문집 Vol.12 No.4

In order to improve air quality of indoor environment, studies of the underfloor air distribution (UFAD) system for application in buildings are actively in progress based on temperature and air flow distribution. However, although the age of air is the major evaluation parameter, there has been very little study on this parameter for the UFAD system. In this study, we investigated the age of air to reach the air diffuser, which is installed at the bottom of the interior by the UFAD system. Computational fluid dynamics simulations showed no regular pattern to the maximum value of the age of air in accordance with air flow rate and the velocity at air diffuser. These factors can be deduced from air movement by considering that air emitted from air conditioners was rotated according to the bottom shape of the floor, and then, the age of air in the rotation center was increased. The average age of air of internal interior was reduced considerably as the flow velocity at the underfloor air diffuser was increased from 0.5 m/s to 1.0 m/s However, the age of air was not substantially affected with change in the air volume. Moreover, when the flow velocity at the underfloor air diffuser was higher than 1.0 m/s, the age of air showed no significant difference with change in air volume or height of measurement. These results imply that indoor air quality is more substantially influenced by flow velocity than air volume, and the appropriate flow velocity is 1 m/s or more.

설계단계에서 건축물의 종합성능 평가

방승기(Seung-Ki Pang),백용규(Young-Gyu Baik),이철구(Chul-Goo Lee),조현(Hyun Cho) 한국생활환경학회 2005 한국생활환경학회지 Vol.12 No.4

We carried out this research in order to examine life-time cost of the building after its completion, its acoustical performance, and the time required for evacuation in the event of a fire. Our research was based on the data obtained from buildings for teenagers. We obtained the following results. First, the analysis of the total cost estimates showed that the most economical case was the case when we used a hot and chilly water generator. Second, the simulation results from an auditorium experiment indicated that the reverberation time at 500 ㎐ was 1.34 seconds when all seats were not occupied whereas it reached 1.1 seconds when all seats were occupied. The differences between the calculated RTs and target RTs were respectively 0.04 and 0.02 seconds. Third, we found that the sound pressure level was relatively uniform because it was located within 4 ㏈. Fourth, simulation results showed that the ZONE 3 turned out to be most effective because its occupants were able to go through each emergency exit within regulated time.

설계단계에서 Multiplex Cinema의 화재 및 피난 성능 평가

방승기(Seung-Ki Pang),안창환(Chang-Hwan Ahn),채영태(Young-Tae Chae) 한국생활환경학회 2006 한국생활환경학회지 Vol.13 No.1

In this study, It is need a phased approach which divided three steps to estimate a appropriate time for evacuating when the fire is occurred in a theater at the Multiplex cinema. First of all, the present status data of the Multiplex Cinema in Korea is collected by statistics to perceive the conditions of the building type. The geometry data and the basic condition on a fire simulation are analyzed. In addition, the simulation research is conducted to predict critical items such as a height of the smoke, fluctuations of the indoor air temperature and optical density, when the fire is ignited a certain position in the theater. Finally, a required evacuation time for total occupants in the building is estimated by SIMULEX to evaluate the location and size of the exit and the distances for evacuation. As the results, the target building could satisfy the several limitations for the occupant's evacuation.

EMP 방호시설의 덕트 및 배관 최적 설계 방안

방승기(Seung-Ki Pang),김재훈(Jae-Hoon Kim) 한국지열·수열에너지학회 2014 한국지열에너지학회논문집 Vol.10 No.4

This study conducted a computational fluid dynamics(CFD) analysis to find an appropriate diameter or sectional area of air ducts and fluid pipes which have an electromagnetic pulse(EMP) shied to protect indoor electronic devices in special buildings like military fortifications. The result shows that the optimized outdoor air intake size can be defined with either the ratio of the maximum air velocity in the supply duct to the air intake size, or the shape ratio of indoor supply diffuser to the outdoor air intake. In the case of water channel, the fluid velocity at EMP shield with the identical size of the pipe, decreases by 25% in average due to the resistance of the shield. The enlargement of diameter at the shield, 2 step, improves the fluid flow. It illustrated that the diameter of downstream pipe size is 1step larger than the upstream for providing the design flow rate. The shield increases friction and resistance, in the case of oil pipe, so the average flow velocity at the middle of the shield increase by 50% in average. In consideration of the fluid viscosity, the oil pipe should be enlarged 4 or 5 step from the typical design configuration. Therefore, the fluid channel size for air, water, and oil, should be reconsidered by the engineering approach when EMP shield is placed in the middle of channel.

EMP 차폐를 위한 도파관 형상과 SE에 따른 유동 특성 평가

방승기(Seung-Ki Pang),안혜린(Hye-Rin Ahn),육종관(Jong-Gwan Yook) 한국지열·수열에너지학회 2016 한국지열에너지학회논문집 Vol.12 No.3

In this study, we evaluated the flow characteristics of various types of waveguide-below-cutoff (WBC) arrays and their shielding effectiveness (SE) of electromagnetic pulses (EMP) based on computational fluid dynamics (CFD). Three types of waveguides were selected for analysis: (1) grid type, (2) honeycomb type, and (3) multi-layer types (2-ply, 4-ply, 6-ply, and 8-ply). To analyze the air flow characteristics, the flow velocities in the longitudinal center of the WBC and the differential pressures between the WBC array inlet and outlet were evaluated. Consequently, we derive the following conclusions: (1) despite an increase in the inlet velocity, the pressure drop of the 6-ply multi-layer type did not significantly increase as compared to that of other types of waveguides (waveguide thickness of 0.1 mm, SE of 100 dB); (2) the grid and honeycomb type had the fastest flow rate of 17.5 m/s, which is approximately 2.5 m/s faster than that at the inlet (waveguide thickness of 1 mm, module size of 30 mm); and (3) the average pressure drop of the grid type waveguide is the lowest in the overall model, whereas that of the 8-ply is the highest (waveguide thickness of 1 mm, module size of 30 mm, and SE of 80, 100 dB).

지하 전산센터의 시설보호를 위한 방폭밸브에 미치는 폭압 평가

방승기(Seung-Ki Pang),신진원(Jin-Won Shin),김외득(Wae-deuk Kim) 한국지열·수열에너지학회 2018 한국지열에너지학회논문집 Vol.14 No.3

This paper presents two-step simulations to calculate the influence of blast-induced pressures on explosion-protection valves installed at the boundary between a protection facility and a tunnel entering the facility. The first step is to calculate the respective overpressure on the entrance and exit of the tunnel when an explosion occurs near the tunnel entrance and exit to approach the protection facility. Secondly, the blast pressures on the explosion-protection valves mounted to walls located near the tunnel inside approaching the protection facility are analyzed with a 0.1 ms time variation using the results obtained from the first-step calculations. The following conclusions could be derived as a results: (1) The analysis of the entrance tunnel scenario, P1, leads to the maximum overpressure of 47 kPa, approximately a half of the ambient pressure, at the inner entrance due to the effect of blast barrier. For the scenario, P2, the case not blocked by the barrier, the maximum overpressure is 628 kPa, which is relatively high, namely, 5.2 times the ambient pressure. (2) It is observed that the pressure for the entrance tunnel is effectively mitigated because the initial blast pressures are partially offset from each other according to the geometry of the entrance and a portion of the pressures is discharged to the outside.

지하 방호시설의 폭압 저감 및 시간 지연을 위한 Expansion Chamber와 Side Chamber 적용

방승기(Seung Ki Pang),신진원(Jin Won Shin) 한국방재학회 2022 한국방재학회논문집 Vol.22 No.6

본 논문에서는 외부에서 폭발이 발생할 경우 지하 방호시설의 side chamber 설치 개수와 expansion chamber의 설치 개수 및 형태를 변화시키고 각 방폭문에 미치는 폭압을 평가하였다. 시뮬레이션은 4가지 기본 형태를 설정하고, 각각의 chamber가 0개, 1개, 2개, 3개 및 4개인 경우에 대해서 평가하였다. 기본형태 지하탄약고는 side chamber가 설치된 경우, 피크의 시간 지연이 40 ms 정도로 나타나 명확하게 나타났지만, 최대값의 저감은 3 kPa로 차이가 크게 나타나지 않았다. 병목장치와 side chamber에 의한 폭압의 저감 및 피크 지연효과를 검토한 결과 지하탄약고 터널의 크기가 일부 축소되기 때문에 효과는 거의 발생하지 않는 것을 알 수 있었다. 통로 폭의 1.1 배 크기의 expansion chamber와 side chamber를 사용한 경우는 피크 지연 및 최대치의 저감 효과가 발생하는 것으로 파악되었으며 이때 설치 개수는 최소 2개 이상 설치해야 효과가 있는 것으로 나타났다. 통로 폭의 120%인 expansion chamber와 side chamber를 동시에 사용하면, 각 chamber를 2개 이상을 사용해야 피크의 지연 및 저감 효과가 큰 것으로 나타났으며, 그 효과는 통로폭의 110%인 경우와 거의 동일한 값으로 나타났다. This study presents numerical investigation of blast overpressures on blast-resistant doors by changing the number of side chambers and the number and shape of expansion chambers for an external detonation. Blast overpressures for four types of door and zero to four chambers were simulated. For the original shape of the underground ammunition magazine with side chamters installed, the peak time delay was approximately 40 ms, showing a clear different, whereas the reduction in the maximum value appeared as small as 3 kPa. Reducing the overpressure and delaying peaks using bottleneck devices and side chambers revealed that, because the size of the tunnel with underground ammunition magazines was partially reduced, the effects of the reduction and time delay of blast overpressures were negligible. When expansion chambers with a size 1.1 times the passage width and side chambers were used, the time delay in the peaks and overpressure reduction were observed. When expansion chambers with a size 1.2 times the passage width and side chambers were used, the delay and reduction effects were significant when two or more chambers were installed, and the effect was almost the same as when the size was 1.1 times the passage width.