• 제목/요약/키워드: thermal transmittance

검색결과 355건 처리시간 0.035초

염료감응형태양전지 모듈 적용 PVT 집열기의 열적 성능 분석 (Analysis Thermal Performance of PV/Thermal Collector with Dye-sensitized Solar Cell Module)

  • 장한빈;문종혁;강준구;김진희;김준태
    • 한국감성과학회:학술대회논문집
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    • 한국감성과학회 2009년도 추계학술대회
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    • pp.273-276
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    • 2009
  • Photovoltaic-thermal(PVT) collectors are a combination of photovoltaic modules with solar thermal collectors, forming one device that receives solar radiation and produces electricity and heat simultaneously. Of various PV modules, dye-sensitized solar cell(DSC) is a relatively new type of solar cell technology that can transmit light while they can generate electricity. With this aspect, DSC can be applied into solar thermal collectors. The object of this study is to evaluate the thermal performance of PVT collector with DSC. The thermal performance of the DSC PVT combind collector was measured in outdoor conditions with the solar radiation of over $700W/m^2$. In this study, the PVT collector with the 30% light transmittance of DSC achieved its thermal efficiency of about 36%.

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프로젝션 TV 적용을 위한 액정 디스플레이의 열적 안정성에 관한 연구 (Study on Thermal Stability of Liquid Crystal Display for Projection TV Application)

  • 강희진;황정연;오용철;서대식
    • 한국전기전자재료학회논문지
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    • 제19권11호
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    • pp.1033-1036
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    • 2006
  • We have investigated electro-optical characteristics in three kinds of twisted nematic (TN) cells on the polyimide surface. The threshold voltage and the response time of thermal stressed TN cells were same that of no thermal stressed TN cells. There were little change of value in these TN cells. On the other hand, transmittance of no thermal stressed TN cells were better than that of thermal stressed TN cells. Transmittances of TN cells on the polyimide surface decreased by increasing thermal stress time. Moreover, the residual DC of the thermal stressed TN cells increased as increasing thermal stress temperature and time. Therefore, thermal stability of TN cells were decreased gradually by giving high thermal stress for a long time.

무기 필러가 유연기판용 폴리에틸렌나프탈레이트 필름 치수안정성에 미치는 영향 (Effect of Inorganic Fillers on the Dimensional Stability of Poly(ethylene naphthalate) Film as a Flexible Substrate)

  • 김종화;김홍석;강호종
    • 폴리머
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    • 제36권6호
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    • pp.733-738
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    • 2012
  • 광전소자용 유연기판으로 사용되는 폴리에틸렌나프탈레이트 필름의 치수안정성 향상을 위하여 첨가된 유리 비드와 유리 섬유가 필름의 열팽창계수와 광투과도에 미치는 영향을 살펴보았다. 첨가된 무기 필러의 함량이 증가할수록 열팽창계수와 광투과도가 감소함을 알 수 있었다. 무기 필러의 크기, 입도 분포 또한 유연기판의 치수안정성과 광투과도에 영향을 미치는 주요한 요인임을 확인할 수 있었다. 본 연구 결과, 유연기판으로 사용 가능한 85% 이상의 광투과도를 유지하면서 폴리에틸렌나프탈레이트의 고유 치수안전성을 50% 이상 감소시키는 무기 필러의 함량은 5 wt% 내외임을 알 수 있었다.

다중층 나노구조체를 통한 열차단 특성 제어 (Analysis of suppressed thermal conductivity using multiple nanoparticle layers)

  • 노태호;심이레
    • 한국표면공학회지
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    • 제56권4호
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    • pp.233-242
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    • 2023
  • In recent years, energy-management studies in buildings have proven useful for energy savings. Typically, during heating and cooling, the energy from a given building is lost through its windows. Generally, to block the entry of ultraviolet (UV) and infrared (IR) rays, thin films of deposited metals or metal oxides are used, and the blocking of UV and IR rays by these thin films depends on the materials deposited on them. Therefore, by controlling the thicknesses and densities of the thin films, improving the transmittance of visible light and the blocking of heat rays such as UV and IR may be possible. Such improvements can be realized not only by changing the two-dimensional thin films but also by altering the zero-dimensional (0-D) nanostructures deposited on the films. In this study, 0-D nanoparticles were synthesized using a sol -gel procedure. The synthesized nanoparticles were deposited as deep coatings on polymer and glass substrates. Through spectral analysis in the UV-visible (vis) region, thin-film layers of deposited zinc oxide nanoparticles blocked >95 % of UV rays. For high transmittance in the visible-light region and low transmittance in the IR and UV regions, hybrid multiple layers of silica nanoparticles, zinc oxide particles, and fluorine-doped tin oxide nanoparticles were formed on glass and polymer substrates. Spectrophotometry in the UV-vis-near-IR regions revealed that the substrates prevented heat loss well. The glass and polymer substrates achieved transmittance values of 80 % in the visible-light region, 50 % to 60 % in the IR region, and 90 % in the UV region.

니켈박막의 두께에 따른 광투과율변화 (Optical Transmittance Variation to Thickness of Nickel Thin Films)

  • 양기원;손정식;곽호원;이행기;박상철
    • 한국안광학회지
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    • 제13권1호
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    • pp.49-52
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    • 2008
  • 목적: 이 논문은 다양한 두께에 따른 니켈박막에 대한 광투과율을 연구한 논문이다. 방법: 다양한 두께를 가진 니켈박막을 통과하는 광투과율을 측정하였다. 결과: 열증착법으로 만든 니켈박막을 통과하는 광투과율의 두께의존성을 연구하였다. 니켈박막의 두께가 70 nm 이하인 경우에 니켈의 박막두께가 증가할수록 광투과율이 급격히 감소하는 경향을 보였고, 70 nm 이상의 경우에는 박막의 두께가 증가할수록 선형적으로 조금씩 감소하는 모습을 보여주었다. 광분산에 대한 실험에서는 빛의 입사하는 방향으로 대부분의 빛이 투과되었다. 이 결과로부터 니켈박막에서는 빛의 분산현상이 거의 없다는 것을 확인할 수가 있었다. 결론: 니켈박막두께가 증가할수록 광투과율이 급격히 감소하였다.

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난방도일 기반 대한민국 행정구역별 기후존 구분 기준 정립에 관한 연구 (A Study on the Classification Criteria of Climatic Zones in Korean Building Code Based on Heating Degree-Days)

  • 노병일;최재완;서동현
    • 설비공학논문집
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    • 제27권11호
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    • pp.574-580
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    • 2015
  • Climatic zone in building code is an administrative district classification reflecting regional climatic characteristics. Use of Degree-Days is a fundamental method that can be used in various building design codes, analysis of building energy performance, and establishment of minimum thermal transmittance of building envelopes. Many foreign countries, such as the USA, the EU, Australia, Italy, India, China, etc., have already adapted climatic zone classification with degree-days, precipitation or amount of water vapor based on the characteristics of their own country's climate. In Korea, however, the minimum requirements for regional thermal transmittance are classified separately for the Jungbu area, Nambu area and Jeju Island with no definite criterion. In this study, degree-days of 255 Korean cities were used for climatic zone classification. Outdoor dry-bulb temperature data from the Korea Meteorological Administration for 1981~2010 was used to calculate degree-days. ArcGIS and the calculated degree-days were utilized to analyze and visualize climatic zone classification. As a result, depending on the distribution and distinctive differences in degree-days, four climatic zones were derived : 1) Central area, 2) Mountain area of Gyeonggi and Gangwon provinces, 3) Southern area, and 4) Jeju Island. The climatic zones were suggested per administrative district for easy public understanding and utilization.

스마트윈도우용 대면적 액정셀 제작과 특성에 대한 연구 (A Study on Fabrication and Characteristics of Large Area Liquid-Crystal Cell for Smart-Window)

  • 이승우
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2019년도 추계학술대회
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    • pp.166-167
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    • 2019
  • Smart windows are used as windows and doors to determine cooling and heating efficiency in the construction field. It's characteristics can increase the energy saving efficiency. In addition, the function of the smart window that can control the light transmittance transmitted from the external environment of the building to the building according to the needs of the user is attracting attention. In this study, a liquid crystal cell capable of controlling light transmittance of 297 × 210 ㎟ was fabricated by using a liquid crystal device as an optical shutter. Analysis of transmittance change according to driving voltage and driving stability according to thermal environment, We confirmed the applicability of building exterior materials as smart windows.

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펨토초 레이저에 의한 폴리이마이드 가공 특성 (Micromachined Properties of a polyimide by a femtosecond laser)

  • 민철기;이만섭
    • 한국레이저가공학회지
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    • 제11권2호
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    • pp.20-25
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    • 2008
  • Polyimide is one of the useful materials in industry. The surface treatment of polyimide by a femtosecond laser can help accurate and fine fabrication of microstructure. And it can change the transmittance and reflectance of polyimide, too. We put femtosecond laser pulses on polyimide for rectangular or square type surface treaments and observe the change of transmittance and reflectance. Pulsewidth is 172 fs, laser power changes for fabrication are from 5 mW to 20 mW, and transmittance and reflectance are measured under 20m W, 300m W, and 920 mW. Pulse patterning is stable and almost no unwanted surface damage is shown. As power increases, working depth increases but working line width does not increase significantly. As speed changes, they also have same results. It shows the efficiency of a femtosecond laser is good and thermal damage is small for polyimide.

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Synthesis, Photophysical and Aggregation Properties of Novel Phenanthrene and Pyrene Substituted Phthalocyanines

  • Kumar, Rangaraju Satish;Son, Young-A
    • Korean Chemical Engineering Research
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    • 제56권6호
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    • pp.792-797
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    • 2018
  • We have explained the synthesis of novel phenanthrene and pyrene substituted phthalocyanines (PC-PHE and PC-PYR) and fully confirmed the structures by its spectral, photo physical and elemental analysis. For these phthalocyanines we checked the UV-Visible absorbance in PGMEA and chloroform and transmittance checked in PGMEA. The transmittance results suggested that these phthalocyanines are showing more than 90% transmittance at the 450-550 nm region. These synthesized molecules are nicely soluble in almost all industrial solvents. We checked the aggregation property of these phthalocyanines in PGMEA, and the results suggested no any aggregation for these molecules in PGMEA. The thermogravimetric analysis results concluded that PC-PHE and PC-PYR had high thermal stability. All studies explain that these new phthalocyanines are more suitable for LCD green color filter application.

현대건축경향에 입각한 건축물녹화시스템 유형의 열적물성치에 관한 연구 (A Study on the Thermal Properties of Architectural Greenery System Typology Based on the Contemporary Architectural Trend)

  • 김태한;이주희;김철민
    • KIEAE Journal
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    • 제13권1호
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    • pp.65-74
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    • 2013
  • Recently, greenery system is frequently applied on buildings and artificial grounds to improve urban ecological functionality. Specifically, architectural greenery is also known as an architectural language that can meet the sustainable design concept of architects. Although the architectural greenery system can be optimized through an interdisciplinary approach between architecture, horticulture and landscape- architecture, there is a problem of communication on the ideal gap between them. Therefore, this study is expected to establish the comtemporary architecture as hi-tech and the organic architecture in internationalism. Moreover, it can analyze the case study on architectural greenery system designed by a Pritzker Prize winner who represents the comtemporary architectural trend. In this analysis, we calculate and compare the U-value of the free-form surface system based on the international standards: ISO and CIBSE etc. Moreover, we calculate a change of artificial soil transmittance respect on compounding ratio of the bottom ash and pearlite. In the case of California Academy of Science by Renzo Piano, total transmittance of the greenery system results in 48% of domestic thermal insulation standard in dry condition. This result will be used as a basic study to promote developing the advanced system based on the concept of consilience.