수소는 기후변화 위기에 대응하기 위한 에너지원 중 하나로 주목받고 있다. 그러나, 수소는 밀폐된 공간에 누출되면 천장으로 상승하여 축적되고, 점화원과 만나면 화재나 폭발의 위험이 있다. 특히, 수소를 운송하거나 연료로 사용하는 선박은 여러 밀폐된 공간으 로 구성되어 있기 때문에 수소를 안전하게 사용하기 위해서는 공간 내에서의 확산 특성을 파악해야 한다. 본 연구는 선박 내 밀폐된 공간 에서 수소와 유사한 특성을 가진 헬륨의 누출방향에 따른 확산 특성을 실험적으로 파악하고, CFD 시뮬레이션을 통해 환기횟수가 25, 30, 35, 40, 45ACH로 증가함에 따라 누출방향에 따른 산소농도 변화를 파악하는 것이 목적이다. 연구 결과, 산소농도감소율은 -z 방향의 누출 이 2%, +x와 +z 방향의 누출이 1%였으며, 환기소요시간은 -z 방향 누출이 15분 30초, +x 방향 누출이 7분, +z 방향 누출이 9분으로 누출방 향에 따라 산소농도와 환기소요시간에 차이가 있음을 보여준다. 또한, 실험공간에서 환기횟수 35ACH 이상부터는 모든 누출 방향에서의 산소농도감소율과 환기소요시간에 유의미한 차이가 없었다. 따라서, 환기횟수를 증가하여도 산소농도와 환기소요시간이 개선되지 않았기 때문에 본 실험환경에서의 적정 환기횟수는 35ACH임을 알 수 있었다.

Senior citizens are reported to be highly sensitive to environmental pollutants, including fine particulate matter. The purpose of this study is to investigate the distributions of fine particulate matter concentrations in town halls and senior citizens’ halls, where senior citizens typically spend a lot of time. The results of this investigation will serve as fundamental data for conducting indoor air quality studies and establishing a regional environmental health policy governing senior citizens’ facilities in Yeongwol county in the future. From January 4 to February 1, 2017, PM10 and PM2.5 concentrations in 170 seniors’ facilities located in Yeongwol county were measured. The average concentrations of PM10 and PM2.5 that were measured from each seniors’ facility chosen from Yeongwol county were 25.1 ± 18.9 μg/m3and 12.5 ± 9.3 μg/m3 respectively. Average concentrations and the average of maximum concentrations were lower than the living space standard of 100 μg/m3 for PM10 and the atmospheric environment standard of 50 μg/m3 for PM2.5, which were set by the Ministry of Environment for populations vulnerable to environmental pollution. As a result of analyzing the sources in seniors’ facilities in Yeongwol county during the winter months, it was found that indoor sources of air pollution such as cooking is main sources rather than outdoor sources of air pollution.

Correct air diffusion is essential for good air quality, comfortable conditions and energy efficiency in mechanical ventilation system. One general method to improve indoor air quality is to simply increase the ventilation rate. This approach, however, often conflicts with building energy efficiency requirement because conditioning outdoor air to the proper temperature, humidity level count for use as ventilation air consumes energy. Therefore, it is necessary for designers to predict the air movement properly. Successful predictions of room airflow yield such information as velocities and temperature distributions, which are useful to building design and analysis. In this paper, the application of computational fluid dynamic (CFD) techniques to large space design and analysis was investigated by comparing the results of CFD simulations and experimental results.

본 연구는 토지피복현황과 수림의 계층구조 등이 다양한 도시녹지를 대상으로 기온 및 급도에 미치는 영향물 점성 빛 정량적으로 파악하기 위해 녹지내의 기온 및 습도를 관측하였다. 그 데이터클 바탕으로 녹지내의 토지피복현황과 기온 및 습도분포, 녹지내의 수목그루와 녹적량및 습도와의 관련성을 회귀분석 둥에 의해 해석 하였다. 그 결과, 고온역은 인공구조물과 나지 주변에서, 저온역은 수림지와 수면 주변에서 형성되었다. 습도는 기온분포에 거의 대응하는 형태로 고온

The purpose of this study is to understand the formation of internal wind paths of open space and its effect on meteorological factors and the generation of negative air ions. Various types of internal wind paths of open space were formed. Subsequently, changes in meteorological factors in each type were measured and the generated negative air ions were analyzed. The four key findings of the study are summarized as follows. First, the average wind speed formed inside the open space was analyzed such that the difference in wind speed was dependent on the difference in the composition of the wind path. Second, the negative air ion generation was observed to have the same trend as the average wind speed difference. Third, changes to the meteorological factors were more evident depending on the difference in wind path formation patterns. Solar radiation was expected to be highly affected by the physical structure (direction) of the target site. The relative humidity was found to show large difference depending on the different wind path type; however, this difference was significantly reduced when converting to absolute humidity. Fourth, it was found that the wind path formation type of open space affects meteorological factors through path analysis, and the changed meteorological factors affect the amount of generated negative air ions. Two conclusions can be obtained based on these results. First, the changes in internal wind speed formation of open space directly reduced the amount of generated negative air ions. Second, the changes in wind speed affect meteorological factors as well as the amount of generated negative air ions.

This study analyzed the placement shape and correlation of green space focusing on anion that is one of curing substances. As its result, it was found out that the meteorological element becomes different and the generated amount of anion also gets different along such different meteorological element in case the shape of placing green space. As the result of analyzing the correlation with meteorological element , it was analyzed that it was the positive correlation in case of time, temperature and relative humidity and it was also analyzed that it was negative correlation in case of wind velocity and amount of light. But, in case of wind velocity, it was considered that the further complement research is required as the sampling distribution was shown as so biased by the windproof effect of the trees planted at the outskirts of green space in case of wind velocity. Based on th analyzed results as above, it suggested the model of generating anion by implementing multiple regression analysis such as y = -2462.383 + 0.304x1 x 72.746x2 x 7.315x3 x - 0.138x4 (x1; time, x2; air temperature, x3; relative humidity, x4; luminous intensity, R2; 0.691).

CFD code are used for numerically testing a new concept of large space air control system. A workshop with air-conditioners products lines and air-conditioned by several floor type air-containers is tested. The whole room air distribution is controlled by boosters installed in a middle height horizontal plane. First, calculated results are compared with measured data to confirm the validity and applicability of the prediction method. Next, the method is applied to case studies heating seasons. Results under some operating conditions show effectiveness in avoid the temperature stratification in winter.

본 실험은 질소시용수준에 따른 수도절간의 조직구조에 미치는 영향과 품종간차이 및 조계구조와 수상특성과의 관련성을 구명코자 실시하였는바 다음과 같은 결과를 얻었다. 1. 각 절간의 대유관속수 및 크기는 질소무비구에 비하여 질소증시구에서 증가하였고, 특히 그 수는상위제 1절간에서, 크기는 상위제3·4·5절간에서 뚜렷한 차이를 나타냈다. 통일계품종은 일반계품종보다 대유관속수가 많았고. 크기가 컸다. 2. 통기강수는 질소를 증시함에 따라 질소무비구에 비하여 많았다. 상위제3·4절간에서 통기강수 및 크기의 품종간차이를 보였고, 특히 상위제 3절간에서 풍산벼와 추청벼는 통기공이 발달되었으나 유신과 진흥은 발달되지 않았다. 3. 대유관속수와 크기 및 절간굵기와 수상특성(수장, 1·2차지경 및 영화수)과는 밀접한 정의 상관을 나타냈다