• Title/Summary/Keyword: Dew-Condensation

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Study on Improvement of Dew Point within ESS Container for Fire Prevention (컨테이너형 ESS 화재방지를 위한 내부 응결점 개선 관한 연구)

  • Kim, Woonhak;Kang, Seokwon;Shin, Giseok
    • Journal of the Society of Disaster Information
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    • v.15 no.2
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    • pp.165-174
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    • 2019
  • Purpose: In this study, we investigated the relationship between the causes of ESS container fire accidents. Method: We investigated the possibility of reducing the container fire accident by improving the air environment of the container which is necessary for improvement of these. Result: Through this study, we can be confirmed that the condensing condition of water in the air caused by the difference of internal and external temperature is improved and the dielectric strength of BMS board is reduced. Conclusion: The correlation between the BMS board condensation and the dielectric strength was confirmed.

A Study on the Problems of the Occupants for the Aspects of the Improper Construction of Housing ( II ) - The Relations between the Actual Conditions (주택의 하자발생으로 인한 소비자문제에 관한 연구( II ) - 주택특성에 따른 하자실태와 피해유형과의 관계 -)

  • 강순주
    • Journal of the Korean housing association
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    • v.3 no.2
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    • pp.75-88
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    • 1992
  • The purpose of this study is to analyze the relations between the conditions of the flaws and the types of damage according to the characteristics of housing, and then to provide with some basic data for the construction of houses of good quality. The effective analytic data for this research are 558 of all 700 questionnaires gathered through distribution collection and personal interviews conducted from June 22, 1992 Through to July 6, towards the first occupants in apartment houses, tenement houses, multidetached houses, multifamily houses and detached houses that last 10 years after construction, located in Seoul and Kyungki-Do. Our major findings are as under:1) Our data reveal that the ratio of flaw occurrence by general type breaks down into noise 53.7%, crack 39.3%, dew condensation 36.9%, windows and doors 36.6%, structure and frame 35.3%, built-in materials 33.3%, the inferiority of equipments/facilities 29.0%, ill drainage 22.0%, and the leakage of water 19.3% average number of flaw occurrence, multi detached house is the highest as 13.7, apartment house 10.5, tenement house 10.5, detached house 10.51 and multifamily house 8.7.3) As regards the degree of flaw occurrence, the flaw of noise is as serious in the degree of occurence as it is high in the ratio of occurrence. Particularly, the following contrastive phenomena are found: multidetached house is normal (2.0) in the degree of occurrence but it is high in the ratio of occurrence: while multifamily house is 2.9 in the degree of occurrence but it is low in the ratio of occurrence.4) In view of the relations between the types of flaws and those of damage, the flaw type which significantly influences on the injury of spirit and health is built-in materials; the flaw types that have considerable effect on the damage of house and home life are the inferiority of equipments/facilities, due condensation, and inferior windows and doors; and the flaw types that have a bad influence over the reliance on the constructors are the inferiority of equipments/facilities, due condensation and built-in materials.

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The diameter and direction of jumping droplets from condensing water on lotus leaves

  • Park, Hyeon-U;Jo, Sam-Geun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.384.2-384.2
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    • 2016
  • Recent publications reported the self-propelled jumping of coalescing dew droplets on superhydrophobic surfaces [1-2]. We further investigated the initial growth, coalescence, and removal by self-propelled ejection of nano and microscopic water droplets on the superhydrophobic surface of lotus leaves under condensing conditions. By using a high-speed digital camera mounted on an optical microscope, we have found: (1) sub-micrometer droplets form and grow on nanoscale waxy hairs; (2) growing droplets coalesce rapidly upon contact, but never jump off the surface unless the diameter of merged droplets exceeds ${\sim}15{\mu}m$; (3) the diameter and direction of jumping droplets are very narrowly distributed, centered at $20-30{\mu}m$ and ${\sim}20$ degrees from the surface normal, respectively. We present a rationale for these observations on the basis of: (a) the hierarchically rough surface structure on nano- and micro-scales; (b) its chemical composition; and (c) the balance among competing forces of cohesion (surface tension), adhesion and gravity.

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A Study of Dew Condensation Characteristics to Switchboard due to Environmental Conditions (환경 조건변화에 따른 배전반 결로 특성에 관한 연구)

  • Kim, Jae-Dol;Oh, Kab-Suk
    • Proceedings of the KAIS Fall Conference
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    • 2011.12b
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    • pp.540-542
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    • 2011
  • 본 논문은 결로 방지 기능을 가진 배전반 개발을 위해 다양한 온습도 환경 조건에서 결로의 생성 및 제거에 관한 특성을 파악하였다. 획득된 결과는 외부 온도변화에 따라 배전반 내부의 온도도 변화되며, 내외부의 온도차는 일정한 차이를 나타내었다. 결로 생성의 특성은 초기에는 미세한 분무상에서 시간이 경과함에 따라 주위 물방울들과 결합하여 성장하며, 최종적으로는 표면장력이 작용하지만 중력에 의해 하부로 처지면서 떨어지는 과정으로 진행되었다. 또한 히터 등으로 결로 생성조건을 파괴시키면 생성시와 동일한 온습도 조건이 유지되어도 결로는 제거되는 것을 알 수 있었다.

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Insulation Method and Performance Evaluation for Fastening Unit of ALC Pannel-Curtain wall (ALC 패널 커튼월의 패스닝 유닛의 단열 방법과 성능 평가)

  • Kim, Bongl-Joo;Kim, Kyeong-A;Park, Je-Min
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2011.05a
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    • pp.107-110
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    • 2011
  • In this study is to improve insulation performance that are the most weak insulation part of fastening unit of the curtain wall. It was produced that thought out to minimize mullion and connecting part, and evaluated performance that make a layer of insulation in the middle by using vibration-proof rubber or silicon. Vibration-proof rubber insulation is 2.6℃~4.0℃ higher and silicon insulation is 2.4℃ higher than non-insulation. Therefore the insulating layer of fastening unit is necessary.

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Economic Study on Heating load by Balcony Remodeling in use of Energy Simulation Program (에너지 시뮬레이션을 이용한 발코니 개조에 따른 난방부하 경제성 고찰)

  • Kim, Sung-Woo;Park, Sang-Hyun;Lim, Jung-Hee;Kim, Byung-Seon
    • Proceedings of the SAREK Conference
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    • 2006.06a
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    • pp.801-806
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    • 2006
  • Balcony space effects indoor thermal environment. When balcony is extended, problems would be made such as noise, dew condensation, over heating energy, and etc. Extend of balcony increase heating load about 47%. occupants must consider remodeling for their balcony. This paper compare extended balcony with unextended balcony on heating load in use of energy simulation program. According to increase heating load, we expected that building heating cost would be increased by extend balcony. To consider extend balcony, occupants must be funished with better date between healing cost increasing and floor area increasing.

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Intelligent Diagnostic System of Photovoltaic Connection Module for Fire Prevention (화재 예방을 위한 태양광 접속반의 지능형 진단 시스템)

  • Ahn, Jae Hyun;Yang, Oh
    • Journal of the Semiconductor & Display Technology
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    • v.20 no.3
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    • pp.161-166
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    • 2021
  • To prevent accidents caused by changes in the surrounding environment or other factors, various protection facilities are installed at the photovoltaic connection module. The main causes of fire are sparks due to foreign substances inside the photovoltaic connection module through high temperature rise and dew condensation in the photovoltaic connection module, and fire due to heat from the power diode. The proposed method can predict the fire by measuring flame, carbon dioxide, carbon monoxide, temperature, humidity, input voltage, and current on the photovoltaic connection module, and when the fire conditions are reached, fire alarm and power off can be sent to managers and users in real time to prevent fire in advance.

Conservation Environmental Assessment and Microbial Distribution of the Songsan-ri Ancient Tombs, Gongju, Korea (공주 송산리 고분 내 미생물 분포 및 보존환경 연구)

  • Lee, Min Young;Kim, Dae Woon;Chung, Yong Jae
    • Journal of Conservation Science
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    • v.30 no.2
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    • pp.169-179
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    • 2014
  • After occurrence of Cyanobacteria in 1997, Songsan-ri tombs located in Gonju have been investigated to monitor for biological damage. The room temperature of Tomb No.6 was $18.6{\sim}19.8^{\circ}C$ and the relative humidity was 94.3~99.9%. The temperature of Royal Tomb of King Muryeong was $17.3{\sim}18.53^{\circ}C$ and the relative humidity was 73.2~96.45%. The variation of relative humidity increased after setting up air vents. If the outside temperature increases, dew condensation occurs on the floor and the north side. When conditioning equipment operates, the maximum temperature differences between walls is $2.8^{\circ}C$. Bacteria from the air of the tomb and on the surface of the walls outnumbered fungi. 20 species of fungi including Alternaria sp., Aspergillus sp., Penicillium sp., and 19 species of bacteria including Pseudomonas sp., Arthrobacter sp., are identified. Microbes in the tombs may damage cultural heritage. The growth possibility of microbes should be estimated because the microbes in the tombs may damage mural painting. The interrelation between microenvironmental condition and biological damage of mural painting should be researched to come up with an long-term conservation method.

The study on corrosion of the inner area of closed box-girder for unpainted weathering steel bridges (무도장 내후성 강 교량의 밀폐형 박스거더 내부의 부식에 대한 고찰)

  • Ma, Seung-Hwan;Noh, Young-Tai;Jang, Gun-Ik
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.4
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    • pp.2391-2400
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    • 2015
  • Weather proof steels are used for steel bridges due to its high corrosion resistance under atmospheric conditions. However, instead of forming stabilized rust layers, general rust occurs on weather proof steels under high humidity condition close to seawater or shady places. In Japan, therefore, they perform rust stabilization treatment instead of unpainted treatment due to severe atmospheric conditions. However, most of domestic weather proof steels were constructed unpainted in the form of closed box-girder, which makes the periodical repetition of dry and wet hard to occur. For the steel bridges constructed on the Han river, the evaporation of water, dew condensation due to temperature change, and stagnant water due to rain affect harmfully on the formation of passive film on weather proof steels. Thus, in this research, in order to analyze corrosion properties inside the closed box-girder for the unpainted weather proof steel bridge in the waterworks safety zone, multiple ways of analysis such as observation with eyes, cellophane-tape test, steel thickness measurement, surface corrosion potential measurement, electron microscope analysis, and X-ray diffraction analysis of the rust were performed. As a result, unstable rust layer was observed inside the closed box-girder, and severe corrosion was observed on the top and bottom of the flanges due to the effects of stagnant water caused by rain, dew condensation, and de-icing materials.

Analysis of the Effectiveness on Instructional Program by Water Circulation System Device (물의 순환 시스템 장치 개발 및 수업 프로그램 효과 분석)

  • Kang, Jung Su;Kim, Hyoungbum
    • Journal of the Korean Society of Earth Science Education
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    • v.11 no.1
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    • pp.21-37
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    • 2018
  • The purpose of the study is to visualize the concept of water circulation in elementary school students through science behavioral system. Elementary school students found it difficult to understand concepts related to the water cycle. Most of the elementary school children think it rains because the clouds are heavier. It is most difficult to explain invisible concepts to elementary school children. Also, experiments in current textbooks are likely to disrupt scientific concepts. Accordingly, conventional water cycle, dew, fog, and cloud experiments were integrated into one system. The researchers then developed a device that allowed students to see the water's circulation at a glance. It is intended to enable integrated thinking on evaporation, condensation and precipitation. In addition, a instruction program to guide students using the system has been developed to demonstrate its effectiveness. Employing a quasi-experimental design, the participants were measured on their concepts of evaporation, condensation, and water circulation before and after participation. The findings indicated that the experiment is more effective in changing the concepts of evaporation, condensation, and water circulation than in previous experiments. Also, the optimal conditions for making use of the device were found, and there were no various experimental parameters, such as condensation.