• 한국수소및신에너지학회논문집
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• 제29권6호
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• pp.606-619
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• 2018

This study focuses on the performance of hydrogen energy based hybrid system in terms of system reliability of electricity generation. With this aim to evaluate the off-grid system of photovoltaic (PV), wind turbine, electrolyzer, fuelcell, $H_2$ tank and storage batteries, 14 different sites in South Korea are simulated using HOMER. Performance analysis includes simulation on the different sites, verification of operational behaviors on regional and seasonal basis, and comparison among a control group. The result shows that the generation performance of hydrogen powered fuelcell is greatly affected by geographical change rather than seasonal effect. In addition, as the latitude of the hybrid systems location decrease, renewable power output and penetration ratio (%) increase under constant electrical load. Therefore, the hydrogen based hybrid system creates the stability of electricity generation, which best suits in the southern part of South Korea.

• KEPCO Journal on Electric Power and Energy
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• 제5권1호
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• pp.11-15
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• 2019

최근 송전전압 격상으로 인해 차단기 또한 정격이 높아지고 있다. 이에 차단부의 전압 정격을 높이기 위한 방법으로 차단부 2개 이상을 직렬로 구성하는 다점절 차단기가 설치되어 운용되고 있다. 다점절 차단기에서 차단부 극간에 설치되는 균압용 콘덴서는 점절간 균등한 전압분배와 초기 과도회복전압을 저감하는 기능을 수행한다. 하지만, 세계적으로 실계통 사용에서 균압용 콘덴서는 기계적인 손상, 절연파괴에 의한 폭발 등 다수의 고장이 발생하고 있어, 이에 대한 원인 규명과 새로운 성능 검증방법에 대한 연구 필요성이 제기 되고 있다. 본 논문에서는 한전 계통에서 주로 발생한 균압용 콘덴서의 절연파괴 원인을 규명하고 이에 대한 제품 성능검증 방법을 제안하고자 한다.

• Nuclear Engineering and Technology
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• 제49권7호
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• pp.1537-1546
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• 2017

Many thermal-hydraulic tests have been conducted at the Korea Atomic Energy Research Institute for verification of the SMART (System-integrated Modular Advanced ReacTor) design, the standard design approval of which was issued by the Korean regulatory body. In this paper, the contributions of these tests to the standard design approval of SMART are discussed. First, an integral effect test facility named VISTA-ITL (Experimental Verification by Integral Simulation of Transients and Accidents-Integral Test Loop) has been utilized to assess the TASS/SMR-S (Transient and Set-point Simulation/Small and Medium) safety analysis code and confirm its conservatism, to support standard design approval, and to construct a database for the SMART design optimization. In addition, many separate effect tests have been performed. The reactor internal flow test has been conducted using the SCOP (SMART COre flow distribution and Pressure drop test) facility to evaluate the reactor internal flow and pressure distributions. An ECC (Emergency Core Coolant) performance test has been carried out using the SWAT (SMART ECC Water Asymmetric Two-phase choking test) facility to evaluate the safety injection performance and to validate the thermal-hydraulic model used in the safety analysis code. The Freon CHF (Critical Heat Flux) test has been performed using the FTHEL (Freon Thermal Hydraulic Experimental Loop) facility to construct a database from the $5{\times}5$ rod bundle Freon CHF tests and to evaluate the DNBR (Departure from Nucleate Boiling Ratio) model in the safety analysis and core design codes. These test results were used for standard design approval of SMART to verify its design bases, design tools, and analysis methodology.

• 한국태양에너지학회 논문집
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• 제37권5호
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• pp.1-11
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• 2017

A study on Nacelle Lidar (Light detection and ranging) measurement error and the data reliability verification was carried out at Haengwon wind farm on Jeju Island. For measurement data error processing, the characteristics of Nacelle Lidar measurements were analyzed by dividing into three parts, which are weather conditions (temperature, humidity, atmosphere, amount of precipitation), mechanical movement (rotation of wind turbine blades, tilt variation of Nacelle Lidar) and Nacelle Lidar data availability. After processing the measurement error, the reliability of Nacelle Lidar data was assessed by comparing with wind data by an anemometer on a met mast, which is located at a distance of 200m from the wind turbine with Nacelle Lidar. As a result, various weather conditions and mechanical movement did not disturb reliable data measurement. Nacelle Lidar data with availability of 95% or more could be used for checking Nacelle Lidar wind data reliability. The reliability of Nacelle Lidar data was very high with regression coefficient of 98% and coefficient of determination of 97%.

• KIEAE Journal
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• 제17권4호
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• pp.41-48
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• 2017

Purpose : Currently, 25% of the domestic energy consumption structure is used as building energy, and more than 18% of this energy is consumed in the residential. Accordingly, various efforts and policies that can save energy of the building is being performed. The various researchers are conducting research to diagnose the thermal performance of existing buildings. This study is to apply in the field of precision thermal insulation performance diagnostic method for thermal performance analysis of existing detached house in Seoul, Gangreung, Gyeongju, Pohang. And this paper is analyzed quantitatively measure the existing detached house energy performance. Method: Research methodology analyzed the thermal performance over the Heat Flow Meter method by applying the measurement process and method by applying the criteria of ISO 9869-1 & ASTR method. In this study, the surface heat transfer coefficient was calibrated by applying indoor surface heat transfer resistance with reference to ISO 6946 standard. The measurement error rate between the HFM diagnosis method and the ASTR diagnosis method was reduced and the measurement reliability was obtained through measurement method error verification. Result : As a result of the study, the thermal performance vulnerable parts of the building were quantitatively analyzed, and presented for methods which can be improved capable of efficient energy use buildings.

• 환경정책연구
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• 제6권2호
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• pp.27-45
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• 2007

본 연구에서는 효과적인 에너지 관리를 위한 경제학적 일반방법론을 기초로 경제적 주요 변수가 고려된 목표조정 및 이행실적 평가 방법론을 제시하였다. 에너지소비 및 원단위는 생산량, 생산구조 등 요인에 의해 직접 영향을 받는다. 따라서 본 연구에서는 목표달성시점의 실질 생산량을 반영해 베이스라인 및 목표 재조정을 하고 이에 기초해 목표달성 도를 평가하였다. 사례분석 결과, 생산량 변동을 고려한 베이스라인 및 목표조정 유무에 따라 평가결과의 차이가 있음을 확인하였다. 본 연구는 성과의 지속적 개선을 축으로 한 적합성 평가제도와 교토메카니즘 활용 과정에서 최근 활발하게 수행되고 있는 온실가스 배출량 검인증 제도에서 핵심이 되는 검증기준 마련에 활용될 수 있을 것으로 기대된다.

• KIEAE Journal
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• 제12권6호
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• pp.39-47
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• 2012

Recently, the green building and energy connection system are establishing. But, National certification system for environment-Friendly Buildings is indicated hangup about energy efficiency of building. Commissioning, energy conservation, renewable energy, carbon dioxide emissions, it is determined that the energy associated with LEED and GBCC four items of the comparative analysis showed the following results. First, on the practical performance of the system after the completion of commissioning of the energy associated with the system completed until after the final performance for secure operation from the planning stage to verify and document systematically how to perform, but the domestic review and verification is incomplete. Second, the use of energy-saving and renewable energy is directly related to the energy consumption of the building, but GBCC the strengthening of standards on how to evaluate it is deemed necessary. Finally, the evaluation of the reduction of carbon dioxide emissions, LEED Unlike GBCC the life-cycle of the system without considering the global warming index only because a substantial step in the operating efficiency can not be assessed. Based on this study GBCC energy savings through efficiency to actively carry out research through a systematic analysis of the basic guidelines to proceed.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2003년도 춘계학술대회 논문집
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• pp.260-264
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• 2003

The application of solar energy, in the field of alternative energy, was on the increase tendency. In the case of advanced nations, through continuous R&D, solar-heat hot-water-boiler with high efficiency has been used for the house and the industrial process on business, advanced nations on reached up the experimental stage of solar generation system. But the actual circumstance of the domestic has been not accomplished the popularization of solar-heat hot-water-boiler and the settlement of it which is the fundamental stage of the solar energy usage. This trouble, the domestic was flooded with small enterprise for producing solar-heat hot-water-boiler, was caused by the popularization and the production without verification of performance. To supply the monitoring program for evaluating solar-heat hot-water-boiler, this research was purpose to improve the technical development of the enterprise for producing solar-heat hot-water-boiler and served as an aid f3r the enlargement and the popularization on solar energy.

• 한국태양에너지학회 논문집
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• 제23권3호
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• pp.93-102
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• 2003

One of the promising optical daylighting systems is light shelf type daylighting system, Two types of lighting performance analysis methods are 1) Ray-Tracing method and 2) Radiosity method. The purpose of this paper is to compare two methods in terms of advantages and disadvantages by further looking at the detail algorithm. Also. model verification with Lightscape simulations has been conducted. Effectiveness of light penetration factor in terms of daylighting factor has been investigated and quantified. In summer time. the performance of the light shelf was twice better than the case without it.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2005년도 동계학술발표대회 논문집
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• pp.217-222
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• 2005

Building energy consumption according to the ventilation has been considered to be an important subject. The purpose of this study is to investigate the cooling loads in a test space with a forced ventilating system. In the test space, on/off controlled air-conditioning and forced ventilating facility were operated between 8:30 to 21:00 during 4 days and some important data like temperatures and energy consumption were measured to obtain actual cooling loads. The simulation was carried out in a mode of temperature level control using a TRNSYS 15.3 with a precisely measured air change amount and performance data of air-conditioner. Cooling loads including sensible and latent were compared between by experiment and by simulation. Both of cooling loads associated with ventilation show a close agreement within an engineering tolerance.