• 한국태양에너지학회 논문집
• /
• 제32권6호
• /
• pp.113-119
• /
• 2012

The heat from PV modules should be removed for better electrical performance, and can be converted into useful thermal energy. A photovoltaic-thermal(PVT) module is a combination of PV module with a solar thermal collector which forms one device that produce thermal energy as well as electricity. In many studies various water type PVT collectors have been proposed in effort to increase their electrical and thermal efficiency. The aim of this study is to evaluate the heating performance of heating system combined with PVT collectors that on integrated building roof. For this study, the BIPVT system of 1.5kWp was installed at the experimental house, and it was incorporated with its heating system. From the experimental results, the solar fraction of the heating system with BIPVT was 15%. It was also found that was analyzed that the heating energy for the house can be reduced by 47%, as the heat gained from BIPVT system pre-heated the water used for heating system.

• 한국태양에너지학회 논문집
• /
• 제32권2호
• /
• pp.1-10
• /
• 2012

A photovoltaic/thermal (PVT)solar system is the solar technology that allows for simultaneous conversion of solar energy into both electricity and heat. This paper compared the performance of PVT system with a conventional PV module and solar collector and analyzed electrical and thermal efficiency of PVT system in terms of solar irradiance and inlet temperature of the working fluid. Based on the experimental data, thermal and electrical efficiencies of he glazed PVT system were57.9% and14.27% under zero reduced temperature condition which were lower by 13.6% than the solar thermal absorber plate and by 0.08% than the PV module respectively. For the unglazed PVT system it had lower thermal efficiency than the solar thermal absorber plate but higher electrical performance than the PV module due to the cooling effect by the working fluid. However, total efficiency of the glazed PVT system was72.2% which was higher than combined efficiencies of the solar collector and PV module. Besides, total efficiency of the PVT system would be much higher if calculated based on unit area.

• 한국태양에너지학회 논문집
• /
• 제25권2호
• /
• pp.53-62
• /
• 2005

In this study, the thermal performance of multi-story double-skin facade(DSF) with variation of cavity height is evaluated to offer useful data in determining cavity height of multi-story DSF. For this, thermal criteria for multi-story DSF is adopted and a DSF model for evaluation of the thermal performance is established. Through the evaluation of CFD simulation, the recommended height of multi-story DSF is 5 stories or less to improve the thermal performance during the intermediate season.

• 터널과지하공간
• /
• 제25권2호
• /
• pp.115-124
• /
• 2015

열에너지 저장은 고온 또는 저온의 잉여 열에너지를 저장하여 수요 발생 시 사용하기 위한 기술로서 에너지의 수요와 공급 사이의 불균형을 해소하고, 이를 통해 에너지 시스템의 효율을 향상시킬 수 있다. 특히 간헐적인 신재생에너지 자원을 열에너지 형태로 변환하거나 저장함으로써 에너지 믹스에서 신재생에너지의 비중을 제고할 수 있으며, 이를 위해서는 열에너지 저장 장치와의 조합이 반드시 필요하다. 지하 암반공동을 이용한 열에너지 저장은 높은 건설비용이 수반되어 그 활용이 제한적이지만, 대규모의 열에너지를 장기간 저장할 수 있는 가장 현실적인 방법이다. 또한 기후조건에 따라 외부로의 열손실이 영향을 받는 지상의 열저장소와는 달리, 열저장 지하 암반공동은 장기 운영 시 주변 암반의 히팅에 따른 열손실의 감소를 기대할 수 있다. 본고에서는 열저장 암반공동의 형상 및 다중배치 설계 시 고려해야 할 주요 인자들을 소개하고, 저장공간의 설계에 대한 가이드라인을 제안하였다.

• 한국태양에너지학회:학술대회논문집
• /
• 한국태양에너지학회 2008년도 추계학술발표대회 논문집
• /
• pp.75-80
• /
• 2008

Recently, Energy savings in buildings has received much attention in response to the increased needs for global warming and better comforts of the occupants in apartment housing. This study proposes the method which uses the sun control window film to reduce the cooling load and heating load improving the thermal performance of the building and it improves an energy efficiency. The film which used in actual measurement has a low shading coefficient and a solar energy transmission. so we measured the surface temperature of the triple Low-e glazing system used and inside temperature according to the change of outside temperature and solar energy to study thermal performance evaluation. As a result, it was helpful to use window film insulation to reduce inside temperature in summer and to keep room warm in winter.

• 동력기계공학회지
• /
• 제20권2호
• /
• pp.79-84
• /
• 2016

The thermodynamic performance of ocean thermal energy conversion with 1 kg/s geothermal water flow rate as a heat source was evaluated to obtain the basic data for the optimal design of cycle with respect to the classification of the working fluid. The basic thermodynamic model for cycle is rankine cycle and the geothermal water and deep seawater were adapted for the heat source of evaporator and condenser, respectively. R245fa, R134a are better to use as a working fluid than others in view of the use of geothermal water. It is important to select the proper working fluid to operate the ocean thermal energy conversion. So, this paper can be used as the basic data for the design of ocean thermal energy conversion with geothermal water and deep seawater.

• 한국감성과학회:학술대회논문집
• /
• 한국감성과학회 2009년도 추계학술대회
• /
• pp.269-272
• /
• 2009

The temperature of PV modules that integrated into building facades or roof increases that could reduce the electrical efficiency of the PV system. In order to incresae PV system's efficiency it is very important to remove the heat from the PV modules. For this purpose, hot air can be extracted from the space between PV modules and building envelope, and used for heating in buildings. The solar collector utilizing this thermal effect is called photovoltaic-thermal(PVT) solar collector. This paper compares the experimental performance of building-integrated PVT collectors that applied on building roof and facade. There are two different case: a roof-integrated PVT type and a facade-integrated PVT type. The experimental results show that the collected thermal energy of the roof-integrated type was 24% higher, compared to that of the facade-integrated.

• 한국태양에너지학회 논문집
• /
• 제33권3호
• /
• pp.51-57
• /
• 2013

Metal curtain wall systems are widely used in high-rise commercial and residential buildings. While aluminum is the most frequent used frame material, steel framing is also reemerging as a high-performance material in glazed curtain walls due to less thermal conductivity and design flexibility. The purpose of this study is to evaluate thermal performance of a steel frame curtain wall system by comparing with a aluminum frame curtain wall system. The thermal transmittance was measured according to KS 2278, and condensation resistance was calculated by the test results according to KS F 2295. The steel framing test specimen showed lower thermal transmittance and temperature descending factor compared to the aluminum framing test specimen.

• 한국태양에너지학회 논문집
• /
• 제39권2호
• /
• pp.45-55
• /
• 2019

More than 76% of the detached houses in Korea are over 20 years old. These old detached houses have poor energy efficiency. According to the 2017 Housing Census (Statistics Korea), more than 50% of low-income families live in detached houses. Therefore, the improvement of energy efficiency in old detached houses is needed from the viewpoint of energy welfare. The general method of building energy modelling for the verification of energy efficiency is based on the construction year data of "Building Design Criteria for Energy Saving" due to the cost and time involved in collecting the thermal performance data of buildings. There is poor accuracy with the deterioration of long-term aging of building materials. Also, the selection of alternatives for energy performance improvement is based on the items to be applied, not a performance improvement goal. It is difficult to calculate energy performance that reflects variations in various parameters with dynamic energy simulations. In this study, the influence of long-term aging is used to accurately predict the energy performance of old detached houses. The building energy modelling method is called ENERGY#, which is a static analysis method based on ISO13790. Energy performance is evaluated by a combination of input variables including building orientation, insulation of walls and roof, thermal performance of windows and window/wall ratio, and infiltration rate. Finally, this study provides a way to determine alternatives that meet energy performance improvement goals.

• 한국태양에너지학회 논문집
• /
• 제31권2호
• /
• pp.47-52
• /
• 2011

Currently, Exterior wall's U-value about building envelope is 0.36 W/$m^2K$(Central Region), but window's one is 2.1 W/$m^2K$ according to air gap of glazing, filling gas, coating and type of windows. The door"s one is 1.6~5.5 W/$m^2{\cdot}K$ depending on material and configuration of door. As such, energy loss per unit of door is considerably larger like windows. The door for the recognition was relatively low because energy loss through the door is relatively small compared to window area. In this paper, thermal performance was analyzed through simulation targeting the door which has thermal break that can improve the insulation performance and doesn't have one. As a results of simulations, case1 was calculated as the average of 1.63 w/m2k and case 2 was calculated as the average of 4.14 w/m2k. The thermal performance of door depends on the type and condition of insulations. As a results of final simulations, Case1 was calculated as 1.06 w/m2k and Case2 was calculated as 1.27 w/m2k. As a results of the experiments, thermal performance of case 1 was measured as 1.28 w/m2k. Error between experiments and simulations is considered problems encountered when creating the samples. The effect of door frame on the overall thermal performance is slight because it's a small proportion of the door frame.