• 신재생에너지
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• 제17권1호
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• pp.40-49
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• 2021

In this study, the optical properties, heat transfer capabilities and chemical reaction performance of a methane thermal decomposition reactor using solar heat as a heat source were numerically analyzed on the basis of the cavity shape. The optical properties were analyzed using TracePro, a Monte Carlo ray tracing-based program, and the heat transfer analysis was performed using Fluent, a CFD program. An indirect heating tubular reactor was rotated at a constant speed to prevent damage by the heat source in the solar furnace. The inside of the reactor was filled with a porous catalyst for methane decomposition, and the outside was insulated to reduce heat loss. The performance of the reactor, based on cavity shape, was calculated when solar heat was concentrated on the reactor surface and methane was supplied into the reactor in an environment with a solar irradiance of 700 W/㎡, a wind speed of 1 m/s, and an outdoor temperature of 25℃. Thus, it was confirmed that the heat loss of the full-cavity model decreased to 13% and the methane conversion rate increased by 33.5% when compared to the semi-cavity model.

• 생물환경조절학회지
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• 제22권3호
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• pp.220-227
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• 2013

본 연구는 온실 운영에 필요한 전력량을 확보함으로서 온실경영비 절감을 목적으로 태양광발전시스템을 온실에 인접한 건물의 옥상에 설치하여 일사량에 따른 발전량을 실험적으로 검토하였다. 연구결과를 요약하면 다음과 같다. 실험기간 동안 수평면 일사량의 최대, 평균 및 최소값은 각각 $26.1MJ{\cdot}m^{-2}$, $14.0MJ{\cdot}m^{-2}$ 및 $0.6MJ{\cdot}m^{-2}$ 정도였고, 일일 전력량은 각각 약 6.1kWh, 3.7kWh 및 0.01kWh 이었다. 그리고 누계 일사량과 전력량은 각각 약 $4,378.2MJ{\cdot}m^{-2}$ 및 1,163.2kWh 정도이었다. 그리고 부하에 의해 소비된 적산전력량의 최대, 평균 및 최소값은 각각 4.5kWh, 2.4kWh 및 0.0kWh 정도이었고, 누계전력량은 739.2kWh 정도로서 발생 전력량의 약 63.5%에 해당하였다. 본 실험에 사용된 시스템의 평균 소비전력량을 기준으로 보면, 온풍기의 용량 및 작동시간이 작은 경우는 충분하지만 큰 경우는 부족한 것으로 나타났다. 어레이 표면온도가 상대적으로 높아지면 일사량에 비례해서 발생 전력이 증가하지 않은 것으로 나타났지만, 두 인자 간에 상관계수는 0.851 정도로서 상관관계가 높은 것으로 나타났다.

• 한국태양에너지학회 논문집
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• 제27권4호
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• pp.147-155
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• 2007

It is essential to investigate the structure and the main characteristic of Home USN (Ubiquitous Sensor Network) technologies in built ubiquitous environment while designing future residential space. For this study, three different housing types have been selected to implement ubiquitous technologies for residential space; those are regular, elderly, and single residence units. It is certain that efficiency of ubiquitous home design is improved if main components of each specific housing type are analyzed precisely in digital way and design models are prepared accordingly. Ubiquitous technology, in conclusion, has to be applied not on)r with systematical mechanism or electronic setting but in human-centered atmosphere as well, keeping with deep consideration for bio-housing service factors in eco-friendly surrounding; we call this Ubiquitous Humanism.

• 한국태양에너지학회 논문집
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• 제36권5호
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• pp.31-50
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• 2016

To develope a greenhouse fog cooling system to control the temperature and relative humidity simultaneously to the target value, a theoretical analysis and experiments were done. The control process includes the measuring of environmental variables, setting and coding of the water and heat balance equations to maintain the target temperature and relative humidity in greenhouse, calculating of the open level of the greenhouse roof window that governs the natural ventilation and spray water quantity, and operating of the motor to open/close the roof window and pump to spray for water. The study results were shown to be very good because the average air temperature in the greenhouse was kept to be about $28.2^{\circ}C$ with the standard deviation of about $0.37^{\circ}C$ compared to the target temperature of $28^{\circ}C$ and the average relative humidity was about 75.2% compared to the target relative humidity was 75% during the experiments. The average outside relative humidity was about 41.0% and the average outside temperature was $27.2^{\circ}C$ with the standard deviation of about $0.54^{\circ}C$. The average solar intensity in the greenhouse was 712.9 W. The wind velocity of outside greenhouse was 0.558 m/s with the standard deviation of 0.46 m/s.

• 한국유기농업학회:학술대회논문집
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• 한국유기농업학회 1999년도 하반기 심포지엄
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• pp.5-24
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• 1999

There are severl types of Eco-village developed in abvanced countries including urban, suburban and rural style. For the establishment of Eco-village in Korea, it was focussed to introduce the rural style which has been developed inyersively in European countries such as Denmark, England and Germany. As a key cencept for Eco-villge it was explained briefly and discussed on the renewable energy(wind power park, bio-mass and solar energy collector and heating system), eco-architure, methane gas device, living machine (wastewater treatment facility) and organic farming. It was also discussed how important the basic standard and guidelines for organic agriculture to run essential for the system. For this reason major principles of international applicable standard(draft) for organically grown foods by FAO/WHO Codex alimentarius was shortly desidered. as one of very suitable type for Environmental Agriculture Districts Program which Korean govenment is going to establish in the near future. In conculusion it was also suggested that positive participation of organic famers, enthusiastic eneagement of inhabitans and support strategy of govemment /NGO groups might play very important role for successful managment of Eco-village ecologically sustainable after establishment.

• 한국유기농업학회지
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• 제9권2호
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• pp.39-54
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• 2001

For the development of Eco-village in Korean rural area, it was focussed to introduce the rural style which has been developed intensively in European countries such as Denmark, England and Germany. As the main concept for Eco-village it was explained briefly in the paper on the renewable energy(wind power park, bio-mass and solar energy collector and heating system), eco-architecture, methane gas device, living machine(wastewater treatment facility) and organic farming. It was also discussed how important the basic standard and guidelines for organic agriculture to run Eco-village environmentally soundly as a whole system and why it is so much essential for the system. For this reason major principles of international applicable standard for organically grown foods by FAO/WHO Codex alimentarius was also shortly described. In the paper the Eco-village concept was considered as a suitable model for Environmental Agriculture Districts Project which Korean government is going to establish at rural area in the near future. In conclusion it was suggested that the positive participation of organic farmers, enthusiastic engagement of inhabitants and support strategy of government/NGO groups might play very important role for successful management of Eco-village ecologically benign and economically sustainable after establishment.

• 생물환경조절학회지
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• 제22권2호
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• pp.91-99
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• 2013

본 연구는 주간동안 온실 내에서 발생되는 잉여 태양에너지 축열 시스템 설계에 필요한 기초자료를 제공할 목적으로 확보한 표준기상년 데이터를 이용하여 벤로형 온실을 대상으로 잉여 태양에너지를 분석하였다. 파프리카의 경우, 지역별 난방부하는 제주, 진주 및 대관령지역에 대해 각각 약 1,107.8GJ, 1,010.0GJ 및 3,118.5GJ로 분석되었다. 잉여 태양에너지의 경우, 제주지역 1,845.4GJ, 진주지역 1,881.8GJ, 대관령지역은 2,061.8GJ로 나타나 대관령지역이 제주 및 진주지역에 비해 각각 11.7% 및 9.6% 정도 크게 나타났다. 국화의 경우, 지역별 난방부하는 제주지역 1,202.5GJ, 진주지역 1,042.0GJ, 대관령지역은 3,288.6GJ 정도인 것으로 분석되었으며 지역별 차이는 파프리카의 경우와 유사였다. 잉여 태양에너지는 제주, 진주 및 대관령지역에 대해 각각 1,435.2GJ, 1,536.2GJ, 및 1,734.6GJ로 나타나 대관령 지역이 제주 및 진주지역에 비해 각각 20.9% 및 12.9% 정도 크게 나타났다. 파프리카를 재배하는 경우가 국화에 비해 상대적으로 지역에 관계없이 난방에너지가 차지하는 비중은 적고 잉여 태양에너지는 많은 경향이 있음을 알 수 있다. 또한 대관령지역을 제외하면 잉여 태양에너지가 난방에 소요되는 에너지보다 많은 것을 알 수 있다. 소요 난방에너지는 지역 및 재배작물별로 다소 차이는 있지만, 오이가 일반적으로 많게 나타났으며, 그 다음으로 국화 및 파프리카 순이었다. 잉여 태양에너지는 대체적으로 파프리카, 오이 및 국화 순으로 많게 나타났다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.70-70
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• 2011

The prospects of current and coming solar-photovoltaic (PV) technologies are envisioned, arguing this solar-electricity source is beyond a tipping point in the complex worldwide energy outlook. Truly, a revolution in both the technological advancements of solar PV and the deployment of this energy technology is underway; PV is no longer an outlier. The birth of modern photovoltaics (PV) traces only to the mid-1950s, with the Bell Telephone Laboratories' development of an efficient, single-crystal Si solar cell. Since then, Si has dominated the technology and the markets, from space through terrestrial applications. Recently, some significant shift toward technology diversity have taken place. Some focus of this presentation will be directed toward PV R&D and technology advances, with indications of the limitations and relative strengths of crystalline (Si and GaAs) and thin-film (a-Si:H, Si, Cu(In,Ga)(Se,S)2, CdTe). Recent advances, contributions, industry growth, and technological pathways for transformational now and near-term technologies (Si and primarily thin films) and status and forecasts for next-generation PV (nanotechnologies and non-conventional and "new-physics" approaches) are evaluated. The need for R&D accelerating the now and imminent (evolutionary) technologies balanced with work in mid-term (disruptive) approaches is highlighted. Moreover, technology progress and ownership for next generation solar PV mandates a balanced investment in research on longer-term (the revolution needs revolutionary approaches to sustain itself) technologies (quantum dots, multi-multijunctions, intermediate-band concepts, nanotubes, bio-inspired, thermophotonics, ${\ldots}$ and solar hydrogen) having high-risk, but extremely high performance and cost returns for our next generations of energy consumers. This presentation provides insights to the reasons for PV technology emergence, how these technologies have to be developed (an appreciation of the history of solar PV)-and where we can expect to be by this mid-21st century.

• 한국태양에너지학회 논문집
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• 제34권4호
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• pp.57-65
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• 2014

In order to reduce greenhouse gas emissions in recent agricultural energy and increase the energy self-sufficiency rate of each farmer, it is extremely important to expand the supply of solar energy using unused space of agricultural facilities, roof. This study surveyed and analyzed the environmental and administrative factors such as problems according to the structure, azimuth and latitude of broiler houses and stability of standard broiler houses required to use broiler house roof based on the poultry houses in Sangju-si. The results can be summarized as follows: 55.6% of the solar energy facilities of according to the classification of arable lands of broiler houses were available, and 31.7% of them were available by classifying according to the azimuth. However, 20.6% of them were available in the survey considering all the arable land and azimuth. In the roof inclination of the broiler houses, from 20 to $25^{\circ}$ was the most common, 30 broiler houses. The broiler houses with the roof inclination more than $20^{\circ}$ accounted for 63% of the total. It was considered that the inclination was generally proper. In the structural safety, only 3 broiler houses that were constructed as a standard broiler house were available. In practice, all but one broiler house was inappropriate to expand the solar energy project using roof. The solar thermal facility weighed $63.6kg/m^2$ in total: the frame and solar thermal collector weighed $27.8kg/m^2$ and $35.8kg/m^2$, respectively. The standard broiler house required to be internally reinforced. This study suggested a plan for internal reinforcement and a feasible plan because there were problems with structural safety when installing solar thermal and photovoltaic systems.

• 한국생물환경조절학회:학술대회논문집
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• 한국생물환경조절학회 1998년도 정기총회 및 학술논문 발표요지
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• pp.54-60
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• 1998

시설재배의 생육은 지상부의 온도에 주로 영향을 받지만, 토양이 저온일 경우에는 양분의 흡수가 불량하고, 토양미생물의 활동이 떨어진다. 특히 세근의 발달이 억제될 뿐만 아니라 코르크화가 촉진되고, 정식후 묘의 활착이 지연되어 토양수분의 흡수가 불량해지므로 생육이 저하된다. (중략)