• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 추계학술대회 논문집
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• pp.171-173
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• 2008

The amount of incident solar rays on inclined surfaces with various directions has been widely utilized as important data in installing solar collector, hot water system, and designing solar buildings and house. This is because the performance of the solar energy applied systems is much affected by angle and direction of incident rays. Recognizing those factors mentioned above are of importance, actual experiment has been performed in this research to obtain the angle of inclination with which the maximum incident rays can be absorbed. The results obtained in this research could be used in designing optimal solar thermal systems.

• 한국지리정보학회지
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• 제13권2호
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• pp.146-156
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• 2010

본 연구의 목적은 효율적 태양광발전시설의 입지를 위하여 가장 큰 변수인 일사량 및 일조시간의 계산 및 추정 정확성을 향상시키는 것이다. 신재생에너지와 관련하여 태양에너지에 관한 연구는 활발히 이루어지고 있지만 태양광발전시설의 입지에 대한 연구는 미흡한 실정이다. 이에 본 연구에서는 GIS환경에서 태양에너지에 가장 영향을 미치는 요인 중 하나인 지리적 요인을 대상으로 일조시간 및 일조량을 계산하였으며, 이 때 산란 일사량을 이용하여 분석 결과를 보정하였다. 또한 입력 데이터가 제공하는 공간해상력을 벗어나는 부분에 대한 값을 추정하기 위하여 공간통계분석방법인 정규 크리깅을 수행하였으며, 정확한 값을 추정하기 위해 데이터들의 공간적 상호관계와 연속성을 파악할 수 있는 베리오그램을 이용하였다. 이 과정에서 베리오그램 인자 값 및 적용 가능한 베리오그램 모델의 추정치 비교를 통하여, 오차율이 가장 작은 모델을 선정하였다. 이는 정확한 태양광발전시설의 입지에 대한 의사결정에 도움을 줄 것으로 사료된다.

• 한국공간구조학회논문집
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• 제16권1호
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• pp.53-64
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• 2016

Solar power is being spotlighted recently as a new energy source due to environmental problems and applications of solar power to curved structures are increasing. Solar panels installed on curved surfaces have different efficiencies depending on its position and the efficient positioning of solar panels plays a critical role in the design of solar power generation systems. In this study, the changing characteristics of solar irradiance were analyzed for hemispherical dome with a large curvature and the positioning of solar panels that can efficiently utilize solar energy was investigated. With an icosahedron-based hemispherical dome consisting of triangular elements as target model, a program for calculating solar irradiance using a normal vector of the solar module on each face was developed. Furthermore, the change of solar irradiance according to the sun's path was analyzed by time and season, and its effects on shades were also examined. From the analysis results, the effective positioning could be determined on the basis of the efficiency of the solar panels installed on the dome surfaces on solar irradiance.

• 한국측량학회지
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• 제38권2호
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• pp.141-151
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• 2020

Since it was first studied in 1980, solar energy analysis model for geographic information systems has been used to determine the approximate spatial distribution of terrain. However, the spatial pattern was not able to be grasped in 3D (three-dimensional) space with low accuracy due to the limitation of input data. Because of computational efficiency, using a constant value for the brightness of the sky caused the simulation results to be less reliable especially when the slope is high or buildings are crowded around. For the above reasons, this study proposed a model that predicts solar energy of vertical surfaces of buildings with four stages below. Firstly, CIE (Commission Internationale de l'Eclairage) luminance distribution model was used to calculate the brightness distribution of the sky using NREL (National Renewable Energy Laboratory) solar tracking algorithm. Secondly, we suggested a method of calculating the shadow effect using ray tracing. Thirdly, LOD (Level of Detail) 3 of 3D spatial data was used as input data for analysis. Lastly, the accuracy was evaluated based on the atmospheric radiation data collected through the ground observation equipment in Daejeon, South Korea. As a result of evaluating the accuracy, NMBE was 5.14%, RMSE 11.12, and CVRMSE 7.09%.

• 신재생에너지
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• 제4권4호
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• pp.72-79
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• 2008

A numerical and experimental studies are carried out to investigate the transient heat transfer characteristics of 5kWth dish type solar air receiver. Measured solar radiation and temperatures at several different locations are used as boundary conditions for numerical a. Many parameters' effects (reflectivity of the reflector, the thermal conductivity of the receiver body, transmissivity of the quartz window, etc.) on the thermal performance are investigated. Discrete Transfer Method is used to calculate the radiation heat exchange in the receiver. A transient heat transfer model is developed and the rate of radiation, convection and conduction heat transfer are calculated. Comparing of the experimental and the numerical results, results of both are in good agreement. Using the numerical model, the transient heat transfer characteristics of volumetric air receiver for dish type solar thermal systems are known and the transient thermal performance of the receiver can be estimated.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 추계학술대회 논문집
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• pp.167-170
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• 2008

A numerical and experimental studies are carried out to investigate the transient heat transfer characteristics of 5kWth dish type solar air receiver. Measured solar radiation and temperatures at several different locations are used as boundary conditions for numerical simulation. Many parameters' effects (reflectivity of the reflector, the thermal conductivity of the receiver body, transmissivity of the quartz window, etc.) on the thermal performance are investigated. Discrete Transfer Method is used to calculate the radiation heat exchange in the receiver. A transient heat transfer model is developed and the rate of radiation, convection and conduction heat transfer are calculated. Comparing the experimental and numerical results, good agreement is obtained. Using the numerical model, the transient heat transfer characteristics of volumetric air receiver for dish type solar thermal systems are known and the transient thermal performance of the receiver can be estimated.

• 한국태양에너지학회 논문집
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• 제31권4호
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• pp.57-65
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• 2011

This study proposes a Passive Solar Chamber System (PSCS) as a passive method for reduction of building energy consumption. Through numerical analysis, the study quantitatively analyzes system performance and aims to provide foundational data for system design. For this purpose, the study configures different system operation modes seasonally and also computes thermal and ventilation performance of the system in accordance with design factors(solar radiation, air channel height and distance). System and ventilation efficiency increases along with increase in solar radiation and air channel distance; however, as the air channel height increases, the efficiencies showed a tendency to decrease. Upon installation of PSCS, an average of $98.23W/m^2$ of heat flux was introduced in the daytime for the month of January in comparison to walls with no PSCS installed. For the month of August, natural ventilation of $56.68m^3/h$ was shown to be supplied to the room.

• 한국추진공학회지
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• 제21권5호
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• pp.29-36
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• 2017

본 연구에서는 수치해석을 통해 장기체공 무인기(HALE UAV)에 사용되는 태양전지에 대해 유동 및 열전달 해석을 수행하였다. 무인기가 운용되는 성층권에서는 강한 태양복사에너지가 유입되며, 자연대류에 의한 열전달이 감소하고 주위 유동에 의한 강제대류의 지배를 받는다. 이러한 환경에서의 태양전지 온도범위를 예측하기 위해 주익에 부착되어 있는 태양전지모듈을 대상으로 복합열전달 해석을 수행하였으며, 성층권 환경에서 시간에 따른 태양복사에너지, 비행속도, 밀도, 온도 등의 외기환경이 태양전지의 온도분포와 열전달 특성에 미치는 영향을 분석하였다.

• 대한기계학회논문집B
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• 제35권12호
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• pp.1383-1389
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• 2011

본 연구는 태양열 발전에 사용하는 공기식 다채널 체적식 흡수기의 일관성 있는 열전달 해석에 초점을 두고 있다. 이를 위해 흡수 소재 물성과 채널 형상 변화의 영향을 몬테카를로 광선추적법에 기반한 광학 모델과 전도, 대류, 복사를 고려한 1 차원 열전달 모델에 동시에 반영하였다. 광학 모델 결과는 채널 반경 대비 길이의 형상비가 매우 커서 대부분의 태양 에너지는 15 mm 이내의 짧은 길이에서 흡수됨을 증명하고 있다. 복사 열손실 분류를 통해 채널의 낮은 흡수율에서는 방사 손실은 줄지만 반사손실이 증가하여 흡수기 효율이 감소하는 것을 보였다. 큰 채널 반경이나 작은 질량 유량으로 인해 흡수기 평균 온도가 상승할 때, 방사 손실과 반사 손실 모두 증가하지만 방사 손실의 영향이 더 큰 것으로 나타났다.

• 한국산업융합학회 논문집
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• 제4권3호
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• pp.319-327
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• 2001

The objective of this study is to clarify the effect of thermal radiation environments on human thermal comfort, depending on different canyon types and surface materials on the human thermal comfort in a housing complex in Pohang city, Korea. For this purpose, the operative temperature and new effective temperature were calculated based on the modified mean radiant temperature of canyon models variated by the existence of direct radiation existence, surface materials, and the width and length of the street spaces in a housing complex. These indices for the canyon have been calculated from the meteorological data of Pohang city, which include air temperature, relative humidity, air velocity, global solar radiation and cloud. And the monthly averages of these climate factors measured at noon have been used. The results are as follows: (1) It is revealed that the short-wave radiosity reached the human body is affected by direct solar radiation and surface materials, and the long-wave radiosity by canyon types. (2) The existence of direct solar radiation, the kinds of surface materials and canyon types affect operative temperature($OT_n$) and new effective temperature($ET^*{_n}$). (3) The analysis of the human heat balance in the canyon indicates that the influence of radiation on human body is marc likely to be affected by the existence of direct solar radiation on human model.