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Design and Feasibility Study of a Real-Time Controlled Kinetic Facade System for Natural Lighting and Ventilation
자연 채광 및 환기를 위한 실시간 제어 키네틱 파사드 시스템 설계 및 적용 가능성 검토
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Jeongyun Hwang, Dohun Lim, Gaeun Kim, Hyunwoo Lim
황정윤, 임도훈, 김가은, 임현우
- Many studies have been conducted to improve indoor environments using kinetic façades that move in response to changes in the external environment. …
- Many studies have been conducted to improve indoor environments using kinetic façades that move in response to changes in the external environment. However, existing studies are limited to analyzing indoor environments at specific times; consequently, fully understanding indoor environments that change in real time is difficult. Among these, studies that simultaneously analyzed indoor lighting and ventilation are relatively insufficient. Herein, we proposed a real-time integrated control system for kinetic façades and natural ventilation systems that satisfied appropriate standards of lighting and ventilation in response to continuous environmental changes. The proposed system used external hexagonal panels and internal windows to control the indoor lighting and ventilation. Real-time proportional-integral-derivative control, according to internal and external environmental changes, was implemented in Grasshopper, and Ladybug simulation was used to evaluate indoor lighting, natural ventilation, and energy analysis according to the control. The analysis showed that satisfying 56% and 80% of the target illuminance range for summer and winter occupancy times, respectively, was possible with natural light through kinetic façade control. Additionally, internal window control provided the required airflow for natural ventilation and reduced the power of the ventilation fan. The application of the integrated control system saved approximately 9% energy consumption in summer and increased approximately 6% energy consumption in the winter. The proposed kinetic façade and natural ventilation system can assist in providing improved indoor comfort. - COLLAPSE
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Design and Feasibility Study of a Real-Time Controlled Kinetic Facade System for Natural Lighting and Ventilation
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Analysis the Effect of Water Reflection with Bifacial Module in Floating PV
수상태양광 양면형 모듈 적용을 통한 수면반사 효과 분석
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Jieun Lee, Hyunsik Jo, Jiyeon Im, Hyun Jun Kim
이지은, 조현식, 임지연, 김현준
- Renewable energy is major agenda to reduce the Carbon Emissions the world. Photovoltaic energy has high potential to achieve the goal. One …
- Renewable energy is major agenda to reduce the Carbon Emissions the world. Photovoltaic energy has high potential to achieve the goal. One of issue in Photovoltaic is increase the power density, in which, bifacial module is took account. Bifacial modules have the optical advantage of greater light collection compared to mono-facial modules. Therefore, bifacial photovoltaic technology has been receiving increasing interest because it promises a higher performance yield and lower levelized cost of energy than mono-facial photovoltaic (PV) technology. Herein, the effect of the bifacial module was compared with that of the monofacial module of a floating photovoltaic located in the valley of a reservoir near a Dam in South Korea. The system consisted of a mono-facial module, bifacial modules, a micro-inverter for checking the power of each module, and insolation for measuring the irradiation and reflection of water. Consequently, the bifacial gain with power generation of the bifacial PV was 4% ~ 5% and the performance ratio was 3.8% ~ 4%. The bifacial gain with only water reflection was maximum 2.74%. - COLLAPSE
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Analysis the Effect of Water Reflection with Bifacial Module in Floating PV
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Effects of Plenum Load on Cooling Capacity Design of Ceiling Radiant Cooling Panels
천장복사냉방 패널의 냉방용량 설계에서 플레넘 부하의 영향
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Kyu-Nam Rhee, Jae-Han Lim, Seong-Ryong Ryu
이규남, 임재한, 류성룡
- This study investigated the impact of the plenum load on the cooling capacity of ceiling radiant cooling panel (CRCP) systems. A two-dimensional …
- This study investigated the impact of the plenum load on the cooling capacity of ceiling radiant cooling panel (CRCP) systems. A two-dimensional simulation model using Physibel BISCO was developed to represent a small room (3.8 m (L) × 2.9 m (H)) equipped with CRCPs. To analyze the plenum load impact depending on the CRCP type (top insulation, and open- or closed-type installation), three cases were considered: closed-type with top insulation (Case 1), closed-type without top insulation (Case 2), and open-type without top insulation (Case 3). The simulation results showed that the presence of the plenum load increased the plenum air temperature and caused the CRCP to absorb part of the plenum load, consequently leading to the enhanced cooling capacity of the CRCPs. When the plenum load increased to 10%–20% of the room load, the cooling capacity was enhanced by 7.9% ~ 16.8%, compared to the case without a plenum load. This implied that CRCPs could be undersized when they are designed without considering the plenum load. Furthermore, the cooling capacity showed a greater enhancement in the CRCPs without top insulation (Cases 2 and 3) than in those with top insulation (Case 1). Particularly, a higher cooling capacity was obtained with a higher water temperature when applying CRCPs without top insulation. The results suggested that open-type CRCPs without top insulation would be a good cooling solution for a room with a plenum because they are suitable for removing the plenum load even at relatively high water temperatures. - COLLAPSE
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Effects of Plenum Load on Cooling Capacity Design of Ceiling Radiant Cooling Panels
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Analysis of Volatility Characteristics of Wind Power Capacity Factors in Korea
국내 풍력발전 이용률의 변동성 특성 분석
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Chunhyun Paik, Yongjoo Chung, Young Jin Kim
백천현, 정용주, 김영진
- The high volatility caused by the intermittent nature of wind power generation adds uncertainty to power grid systems. Herein, we analyzed the …
- The high volatility caused by the intermittent nature of wind power generation adds uncertainty to power grid systems. Herein, we analyzed the characteristics of domestic wind power output by focusing on the volatility of capacity factors. Initially, the average characteristics and the number and duration of ramps, which are representative measures of the volatility of the capacity factors, were analyzed by year and month, using the data for 2018 ~ 2022 with a temporal resolution of 1 h. Subsequently, we generated data at various resolution levels using the 2019 data with a temporal resolution of 5 min and analyzed how the number and duration of ramps were affected according to the resolution. The results showed that the frequency and duration of ramps strongly depended on the time resolution of the data, and that evaluating and considering ramp characteristics can assist in enhancing the flexibility of power system operations by mitigating rapid ramp events. - COLLAPSE
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Analysis of Volatility Characteristics of Wind Power Capacity Factors in Korea
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Current Status of Green Remodeling Project and ECO2-OD: A Study on the Comparison of Characteristics by Buildings Using the Program
그린리모델링 사업의 현황과 ECO2-OD 프로그램을 활용한 건물별 비교에 관한 연구
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Ain Yoo, Kanghyun Kim, Youngjin Choi
유아인, 김강현, 최영진
- As environmental pollution increases globally, there is an increasing interest to reduce greenhouse gases. Accordingly, the government is aiming to expand carbon …
- As environmental pollution increases globally, there is an increasing interest to reduce greenhouse gases. Accordingly, the government is aiming to expand carbon neutrality by 2050, with the goal of achieving a low recycling rate by 2050. This study investigated the expansion status of the green remodeling section of carbon-neutral pillars and converted the results after expanding each pillar to the right using the ECO2-OD program. The results revealed several problems while conducting green remodeling projects. Additionally, because expansion was considered using the ECO2-OD program, the effect of the converted file modeling business in the older age group was higher. The results of this study suggest that the corrosive effects and problems associated with green remodeling can be improved and used as basic data for green remodeling projects. - COLLAPSE
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Current Status of Green Remodeling Project and ECO2-OD: A Study on the Comparison of Characteristics by Buildings Using the Program
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Comparing the Performance of Dimensional Reduction and Model Prediction Performance Due to Missing Data Handling for Building Energy Data Analysis
건물 에너지 데이터 분석에서 결측치 처리방식에 따른 차원 축소 및 모델 예측 성능 비교
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Kyungjae Lee, Hyunwoo Lim
이경재, 임현우
- Handling missing values during data analysis is an important issue that directly affects the prediction performance of models and research results. However, …
- Handling missing values during data analysis is an important issue that directly affects the prediction performance of models and research results. However, research on the differences between the dimensionality reduction rate and model prediction performance is still lacking for building energy-related data. Therefore, this study compared the dimensionality reduction rate and model prediction performance by handling missing values in weather information datasets, which is related to building energy. The missing value-handling methods were divided into removal, k-nearest neighbors (KNN) imputation, and no handling. Dimensionality reduction methods were classified based on principal component analysis and feature selection using the model. Further, the eXtreme Gradient Boosting (XGBoost) algorithm, a gradient boosting method with its own missing data handling capabilities, was used. Consequently, few principal components were required to explain 95% of the variance in the raw data when the missing values were removed than when they were replaced with KNN. Moreover, the dimensionality reduction methods of model building and feature selection outperformed principal component analysis in terms of dimensionality reduction rate and model predictive accuracy. Particularly, the XGBoost model without missing values had the highest accuracy, suggesting that the missing-value handling method of XGBoost may be superior to conventional missing-value handling methods. These results may have important implications for selecting imputation methods in building energy data analysis, considering the effort and cost of missing value handling, and can significantly reduce the cost and effort of data preprocessing. - COLLAPSE
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Comparing the Performance of Dimensional Reduction and Model Prediction Performance Due to Missing Data Handling for Building Energy Data Analysis
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Analysis of Heat Transfer Characteristics and Electrical Performance of BIPV Systems Using a 3D Thermal Analysis
3차원 동적 열전달해석 방법론을 이용한 BIPV 시스템의 열전달특성 및 발전성능 분석
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Subin Jeong, Jinhee Kim, Juntae Kim
정수빈, 김진희, 김준태
- A building-integrated photovoltaic (BIPV) system integrates solar modules into the exterior structure of buildings. Particularly, in countries with limited land area and …
- A building-integrated photovoltaic (BIPV) system integrates solar modules into the exterior structure of buildings. Particularly, in countries with limited land area and many high-rise buildings, such as Korea, BIPV is a favorable technology for securing building energy production capacity. Herein, a three-dimensional dynamic thermal analysis was conducted on the most widely applied curtain wall-integrated and spandrel-integrated BIPV systems in Korea. The analysis involved deriving the rear temperature of the module to examine the power-generation efficiency and output under actual operating conditions. The power generation efficiency of the curtain wall-integrated BIPV system decreased by a maximum of 4.35% compared with that of the individual modules, whereas it decreased by a maximum of 5.10% for the spandrel-integrated system. - COLLAPSE
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Analysis of Heat Transfer Characteristics and Electrical Performance of BIPV Systems Using a 3D Thermal Analysis
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Development of High-Efficiency Flat Plate Collector with Double Glazing
이중 투과체를 갖는 고효율 평판형 집열기 개발
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Song Seop Lee, Wang Je Lee, Deuk Won Kim, Kyung Ho Lee, Ji Hyeon Kim, U Cheul Shin
이송섭, 이왕제, 김득원, 이경호, 김지현, 신우철
- Conventionally, solar thermal systems in South Korea have primarily focused on domestic hot water supply and partial space heating. However, with the …
- Conventionally, solar thermal systems in South Korea have primarily focused on domestic hot water supply and partial space heating. However, with the recent expansion of applications to include industrial process heat and space heating in greenhouses with seasonal heat storage, there is an increasing requirement for developing highly efficient solar collectors that can operate effectively throughout the year. A solar thermal collector absorbs incoming solar radiation, converts it into thermal energy, and then transfers the energy to a heat-transfer fluid. The entire process should be optimized to minimize energy loss and ensure economic efficiency. A flat plate collector with single glazing is highly efficient at low temperatures and high solar intensities, whereas an evacuated tube collector is relatively efficient at high temperatures and low solar intensities. Therefore, in this study, we proposed a flat plate collector with double glazing that exhibited excellent thermal performance under all operating conditions. We validated the thermal performance through theoretical analysis and empirical experiments. In the theoretical analysis, we presented an analytical model for the comprehensive modeling of the flat plate collector and examined its thermal performance based on key design parameters, such as solar transmittance, emissivity, and gas fill. The thermal performance was confirmed, and an optimal design solution was derived. Furthermore, to validate the accuracy of our analysis, we conducted thermal performance testing on an optimized flat plate collector with double glazing, according to the specifications outlined in KS B 8295. The results showed a correlation between the simulation and experimental results. - COLLAPSE
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Development of High-Efficiency Flat Plate Collector with Double Glazing
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Analysis of Occupant Satisfaction and Energy Use Characteristics of Fire Fighting Facilities Based on Energy Efficiency Remodeling
소방 업무시설 에너지 효율화 리모델링에 따른 재실자 만족도 및 에너지 사용 특성 분석
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Su Jin Im, Ga Young Cho
임수진, 조가영
- In this study, after applying passive and active remodeling technologies to firefighting facilities, we analyzed their energy use characteristics by analyzing tenant …
- In this study, after applying passive and active remodeling technologies to firefighting facilities, we analyzed their energy use characteristics by analyzing tenant satisfaction and energy use patterns. According to the satisfaction survey, occupants were most satisfied with the use of new and renewable energy-based hot water among the remodeling elements and the building insulation performance. According to the seasonal energy use analysis, electricity use increased in winter compared to that before remodeling owing to the use of air conditioning and heating, and electricity use decreased in summer compared to that before remodeling owing to better electric heat pump efficiency. By analyzing the 24 h energy use patterns, we found different energy use patterns according to the characteristics of the space based on the daily schedule of firefighters. Based on this, firefighting facilities are characterized by high energy use for seasonal air conditioning and heating. Therefore, when remodeling firefighting facilities in the future, designing them by prioritizing air conditioning efficiency, hot water supply, and insulation performance is necessary. - COLLAPSE
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Analysis of Occupant Satisfaction and Energy Use Characteristics of Fire Fighting Facilities Based on Energy Efficiency Remodeling
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Peak Shaving Methods to Reduce Aerodynamic Loads for Pitch-controlled 20 MW Class Horizontal Axis Wind Turbine Rotor
20 MW 급 피치제어형 수평축 풍력터빈 로터의 공력하중 저감을 위한 첨두절삭 방법 및 영향 연구
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Kang-Ho Jang, Ki-Wahn Ryu
장강호, 유기완
- In this study, we propose a peak shaving method for reducing aerodynamic loads in a pitch-controlled 20 MW class horizontal-axis wind turbine. …
- In this study, we propose a peak shaving method for reducing aerodynamic loads in a pitch-controlled 20 MW class horizontal-axis wind turbine. The wind turbine rotor experiences maximum aerodynamic loads at the rated wind speed, and minimizing these loads is crucial for structural integrity and levelized cost of energy (LCoE) reduction. The peak shaving method involves additional pitch or rpm control near the rated wind speed to reduce these peak loads. Various cases of the peak shaving method were compared using the comprehensive wind turbine aeroelastic analysis code, FAST. We focused on analyzing the impact on aerodynamic, inertial, and gravitational loads, particularly rotor thrust and flap-wise bending moment, and investigated changes in the P-V curve. The variations in annual energy production due to changes in the P-V curve were estimated, and a comparative analysis was conducted from the LCoE perspective. The results demonstrate that the peak shaving method effectively reduces aerodynamic loads on the wind turbine, offering improved performance and cost benefits, thereby promoting sustainable wind energy production. - COLLAPSE
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Peak Shaving Methods to Reduce Aerodynamic Loads for Pitch-controlled 20 MW Class Horizontal Axis Wind Turbine Rotor
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A Study on Enhancement of Electrochemical Performance of EDLC by Cell Optimization
셀 최적화 공정을 통한 전기이중층 커패시터의 성능 향상 연구
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Seongki Ahn, Minseong Bae, Sunkyung You, Jinjoo Park, Hyeongjun Kim, Daewon Kim, Hanjoo Kim, Hong-Il Kim
안성기, 배민성, 유선경, 박진주, 김형준, 김대원, 김한주, 김홍일
- Electric double-layer capacitors (EDLCs) are widely used as electrochemical energy storage devices for various electric devices because of their excellent electrochemical properties, …
- Electric double-layer capacitors (EDLCs) are widely used as electrochemical energy storage devices for various electric devices because of their excellent electrochemical properties, such as fast charging, greater power density than that of lithium-ion batteries, and superior cyclability. Cell optimization is necessary for enhancing the electrochemical performances of EDLCs. In this study, cell optimization was performed using cathode/anode balancing and several electrolyte additives. Cathode and anode balancing is conducted by controlling the cathode thickness from 140 to 220 μm. Consequently, EDLCs assembled with a cathode (200 μm) and anode (120 μm) show good cyclability at 3.2 V. Furthermore, the EDLC prepared with 1.0 M SBPBF4/ACN + PS showed favorable cycle stability for 500 cycles. - COLLAPSE
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A Study on Enhancement of Electrochemical Performance of EDLC by Cell Optimization
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Analysis of the Effect on Wake Decay Constant of Jensen Wake Model in a Wind Farm
풍력단지에서의 Jensen 후류모델 후류감소계수 영향 분석
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Kyoungboo Yang, Kyungnam Ko
양경부, 고경남
- Wind turbines exchange wake effects with each other on wind farms, resulting in wake loss that reduces the power production of the …
- Wind turbines exchange wake effects with each other on wind farms, resulting in wake loss that reduces the power production of the wind farm. Various wake models have been developed to calculate these wake effects. Among them, the Jensen wake model is the most widely used. The model has a wake decay constant parameter for considering the topographical environment of the wind farm. However, setting this wake decay constant relies on the subjective judgment of the designer. In this study, a simulation program was developed to examine the effect of the wake decay constant of the Jensen wake model. The simulation results were compared with data collected from an actual wind farm. Consequently, the output of the downstream wind turbine was reduced due to the wake. By analyzing the effect of the wake decay constant, when the recommended value was applied, the results matched the measured values in certain cases but did not in others. However, when the wake decay constant calculated using the turbulence intensity was applied, the results were generally similar to those of the actual data. - COLLAPSE
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Analysis of the Effect on Wake Decay Constant of Jensen Wake Model in a Wind Farm
Journal Informaiton
Journal of the Korean Solar Energy Society
Journal of the Korean Solar Energy Society
Korean Solar Energy Society
한국태양에너지학회
SJ Tower 804, 249, Hannuri-daero, Sejong-si, 30127, Korea
Tel: +82-44-864-1977 / Fax: +82-44-864-1978 / E-mail: solar@kses.re.kr Copyright© Korean Solar Energy Society. Powered by APUB
Tel: +82-44-864-1977 / Fax: +82-44-864-1978 / E-mail: solar@kses.re.kr Copyright© Korean Solar Energy Society. Powered by APUB