• 자원환경지질
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• 제51권1호
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• pp.67-76
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• 2018

본 연구는 해외 친환경에너지타운에서 보어홀 지중열 저장(BTES) 기술을 활용한 융복합 열에너지 공급 시스템의 3가지 사례로서 캐나다의 ADEU(Alexandra District Energy Utility) 및 DLSC(Drake Landing Solar Community)와 덴마크의 Brædstrup Solpark를 조사하였다. 이들 지역 냉난방 시스템들은 효율과 지속가능성을 높이기 위하여 다중 에너지원을 활용하고 있다. ADEU는 리치몬드시에서 726 개의 지중열교환기로 이루어진 지열필드 및 천연 가스 백업 보일러를 이용한 대규모 지역에너지 공급을 위해 개발되었다. 그리고 캘거리시 인근 Okotoks에 위치한 DLSC는 여름철에 풍부한 태양열 에너지를 144 개의 지중열교환기를 통하여 지중에 저장하고 겨울철 난방을 위해 각 주택에 열에너지를 분배하는 계간축열 방식의 지역난방 시스템이다. Brædstrup Solpark 지역난방 시스템은 태양열, 히트 펌프, 보일러 플랜트 및 계간축열을 위한 48 개의 지중열교환기로 구성되며 다중 에너지원을 이용하여 열을 저장한다. BTES 시추공의 심도와 축열량은 지하수 유동과 지반의 열물성에 따라 영향을 많이 받는다. 이러한 시스템들은 경쟁력 있는 에너지 가격으로 장기적인 에너지를 공급함으로서 신뢰성과 경제성을 평가 받았다. 그리고 ADEU와 Brædstrup Solpark는 서비스 영역 확장을 위한 장기 에너지 공급 계획을 기반으로 확장이 진행중이다. 본 조사를 통하여 이러한 시스템들은 사회 경제적인 이익 뿐만아니라 환경적인 관점이 설계에 반영되어 있는 것을 알 수 있었다. 국내에서도 이러한 프로젝트를 실시하기 위해서는 지방 정부 또는 관련 기관의 에너지 정책 지원 뿐만아니라, 관리 기관 설치를 통한 장기적인 협력이 필요하다.

• 태양에너지
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• 제18권3호
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• pp.197-203
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• 1998

A 5 ton/day pilot scale two-phase anaerobic digester was constructed and tasted to treat Korean food wastes in Anyang city. The process was developed based on 3 years of lab-scale experimental results on am optimim treatment method for the recovery of biogas and humus. Problems related to food waste are ever Increasing quantity among municipal solid wastes(MSW) and high moisture and salt contents. Thus our food waste produces large amounts of leachate and bed odor in landfill sites which are being exhausted. The easily degradable presorted food waste was efficiently treated in the two-phase anaerobic digestion process. The waste contained in plastic bags was shredded and then screened for the removal of inert material such as fabrics and plastics, and subsequently put into the two-stage reactors. Heavy and light inerts such as bones, shells, spoons and plastic pieces were again removed by gravity differences. The residual organic component was effectively hydrolyzed and acidified in the first reactor with 5 days space time at pH of about 6.5. The second, methanization reactor part of which is filled with anaerobic fillters, converted the acids into methane with pH between 7.4 to 7.8. The space time for the second reactor was 15 days. The effluent from the second reactor was recycled to the first reactor to provide alkalinities. The process showed stable steady state operation with the maximum organic rate of 7.9 $kgVS/m^3day$ and the volatile solid reduction efficiency of about 70%. The total of 3.6 tons presorted MSW containing 2.9 tons of food organic was treated to produce about $230m^3$ of biogas with 70% of methane and 80kg humus. This process is extended to full scale treating 15 tons of food waste a day in Euiwang city and the produced biogas is utilized for the heating/cooling of adjacent buildings.

• 한국항공우주학회지
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• 제36권12호
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• pp.1216-1221
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• 2008

본 논문에서 고려된 저궤도 위성은 고정형 태양 전지판을 가지기 때문에 낮구간(daylight) 동안에 태양전지판이 태양지향(sun-pointing) 자세를 유지하고, 관측 임무 수행을 위해 태양 전지판 방향과 반대방향에 위치한 탑재체가 지구지향(nadir-pointing)이 되도록 자세를 변경한다. 이 때 낮기간의 대부분을 차지하는 태양지향 자세에서는 위성 패널(panel)로 입사하는 외부 열환경 요인이 지구 복사열과 알비도(Albedo)이기 때문에, 비교적 안정적인 열환경 조건을 가지고 있다. 이에 반하여, 관측 임무를 수행하는 궤도 10% 정도의 지구지향 자세에서는 위성의 열환경 조건에 가장 지배적인 영향을 주는 태양광이 위성 패널에 영향을 준다. 비록 위성이 비교적 짧은 시간 동안에 지구 지향의 자세를 유지하지만, 이러한 열한경 조건의 변화 때문에 위성의 열설계에서 지구지향의 임무 자세에 따른 열적 영향에 대한 검토가 필요하다. 본 연구에서는 열해석 모델에 관측 임무 구간 동안의 지구지향 자세를 반영한 열해석 결과를 통하여 그 영향을 알아보았다.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 춘계학술발표대회 논문집
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• pp.311-317
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• 2008

As outdoor environment become worse due to concentration of population in large cities, the importance of environmental control strategies such as the arrangement of green space or water space and ventilation paths, has been increasingly recognized. However, most of the studies focus on the assessment on outdoor thermal environment, few studies focus on the interrelationship between thermal environment in residential block and human thermal comfort. The aims of this study is to develop the outdoor planning method to reduce the heating/cooling load in an apartment unit or entire block by the sustainable approaches in outdoor environmental design. In this paper, on the basis of the prior studies, the effect of the outdoor thermal environment on human thermal comfort will be analysed.

• 한국태양에너지학회 논문집
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• 제30권5호
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• pp.56-62
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• 2010

The integration of PV modules into building facades or roof could raise their temperature that results in the reduction of PV system's electrical power generation. Hot air can be extracted from the space between PV modules and building envelope, and used for heating in buildings. PV/thermal collectors, or more generally known as PVT collectors, are devices that operate simultaneously to convert solar energy from the sun into two other useful energies, namely, electricity and heat. This paper compares the experimental performance of BIPVT((Building-Integrated Photovoltaic Thermal) collectors that applied on building roof and facade. There are four different cases: a roof-integrated PVT type and a facade-integrated PVT type, the base models with an air gap between the PV module and the surface, and the improved models for each types with aluminum fins attached to the PV modules. The accumulated thermal energy of the roof-integrated type was 15.8% higher than the facade-integrated regardless of fin attachment. The accumulated electrical energy of the roof-integrated type was 7.6% higher, compared to that of the facade-integrated. The efficiency differences among the collectors may be due to the fact that the pins absorbed heat from the PV module and emitted it to air layer.

• 설비공학논문집
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• 제27권7호
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• pp.369-374
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• 2015

This study analyzed analyzes the energy performance of six houses in Daejeon completed which were built in 2011. Observed The observed houses, which were all designed and constructed inof the same size and structure, are were highly insulated with triple Low-E coating windows; the insulation level of the walls is was $0.13W/m^2K$ and that of the roof is was $0.10W/m^2K$. As electric houses, all of the energy supplied to the houses, including for cooking, is was supplied by electricity. A and 3~4 kWp of photovoltaic system and a 3~5 kW of ground source heat pump (GSHP) were installed in each house tofor providing provide space heating/and cooling and hot water are installed. We constructed a Web-based remote monitoring system in order to understand energy consumption and the dynamic behavior of the energy system. T, and the results of our metering data analysis of 2013 are as follows. First, the annual residential energy consumption is was 4,400 kWh (${\sigma}=1,209$) and GSHP energy consumption is was 5,182 kWh (${\sigma}=1,164$). Second, residential energy consumption ranked highest in average energy usage, with at 45% of the total, followed by heating with at 30%, hot water supply with at 17% and cooling with at 6%. Third, the average energy independence rate is was 51.8%, the GFA (Gross gross floor area) criteria average energy consumption unit is was $48.7kWh/m^2yr$ (${\sigma}=10.1$), and the net energy consumption unit (except the energy yield of the PV systems) is was $24.7kWh/m^2yr$ (${\sigma}=8.8$).

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.678-683
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• 2005

Korea is utilizing geothermal resources mainly in the bathing and swimming facilities with very few applications for industrial processes or space heating. It is estimated that geothermal capacity and annual utilization are 36.2MWt and 761TJ/year as compared to global capacity and annual utilization of 15,145MWt and 190,699 TJ/year. RETScreen software is a user's friendly tool for analyzing the technical and financial pre-feasibility of potential Renewable Energy (RE) projects that promotes the use of RE applications through the capacity building of planners, decision-makers and industries for successful implementation of RE projects. Strong ties between Canada and Korean organizations such as Korean Solar Energy Society (KSES) and the Korea Institute of Energy Research (KIER) exist for knowledge transfer about RETScreen. In this paper, an overview of RETScreen and its ground source heat pump (GSHP) model with a practical example of an existing project of a community hall in Canada are described to illustrate effectiveness of RETScreenin the implementation of RE technologies. The same community hall project is then evaluated hypothetically considering its location at Kangnyng, Korea. The main objective is to demonstrate how RETScreen GSHP model can also be utilized effectively for GSHP applications in Korea.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 춘계학술발표대회 논문집
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• pp.184-189
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• 2008

These days, Apartment is altered oversized and high-rise through construction techniques development. Also, the cost of cooling and heating load would be expected by balcony expansion into inner space caused by legalization. In specially, HVAC systems of high-rise residential building almost apply to pre-existence techniques of middle and low residential building except for consideration and methods of the air inflow minimization into indoor through mechanical ventilation is used in ventilation system. From these cause, window systems of high-rise apartments stands high in estimation of components. Thus, purpose of this study is to make a comparative study through difference of window systems.

• KIEAE Journal
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• 제7권4호
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• pp.57-62
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• 2007

At the moment, the reduction of building energy consumption is a unavoidable task of mankind for conserving global environment. Decreasing overall U-value of building envelope and air infiltration, especially in Korean climate condition with clear four seasons, are the obvious solutions for the objective. Thus low glazing ratio with small window openings are required for heating and cooling load reduction in buildings. Using larger window openings could provide better natural ventilation but it also increases the direct solar radiation penetration into indoor space, heat gain in summer and heat loss in winter. On the other hand, the ventilation rates decreasing problem with smaller window openings could be occurred. As a solution for it, the use of casement window can cause increasing natural ventilation rates by wing wall effect. This paper focuses on deduce the most efficient opening type of casement window in Korean climate. To estimate ventilation performance of each opening types, CFD simulation was used. The best performance of opening type in every wind direction is opening both windows to the center and the most appropriate opening type for Korean climate is also opening both windows to center.

• 항공우주기술
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• 제3권2호
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• pp.42-49
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• 2004

발사단계 중 fairing jettison에서 separation에 이르는 과정에서 위성체의 부품박스가 가지는 온도를 worst hot 조건에 대하여 해석적 방법을 이용하여 구하였다. Fairing jettison 이후에 위성체에 가해지는 외부 열환경과 박스 자체 내부에서의 발열, 박스 자체의 온도에 의한 방사열을 고려하여, 하나의 질량으로 가정할 수 있는 박스에 대한 온도 지배방정식을 해석해가 존재하는 1차 상미분 방정식으로 단순할 수 있었다. 특히, 고려하는 박스의 질량의 변화여부에 따라 해석해가 다른 지배방정식이 유도되었고, 각 경우에 대하여도 단순화된 식 내의 상수항의 조건에 따라 서로 다른 해석해가 존재하였다. 또한, 유도된 해석해를 실제 위성체인 STSAT-1의 worst hot 발사 조건에 대하여 적용하여 위성체 상단에 부착한 부품 박스의 온도를 예측하여 보았고, 이를 통하여 해석해의 유용성을 검증하였다.