• Asian Journal of Atmospheric Environment
• /
• v.11 no.4
• /
• pp.270-282
• /
• 2017

To evaluate the deposition amount on a ground surface, mesoscale numerical models coupled with atmospheric chemistry are widely used for larger horizontal domains ranging from a few to several hundreds of kilometers; however, these models are rarely applied to high-resolution simulations. In this study, the performance of a dry and wet deposition model is investigated to estimate the amount of deposition via computational fluid dynamics (CFD) models with high grid resolution. Reynolds-averaged Navier-Stokes (RANS) simulations are implemented for a cone and a two-dimensional ridge to estimate the dry deposition rate, and a constant deposition velocity is used to obtain the dry deposition flux. The results show that the dry deposition rate of RANS generally corresponds to that observed in wind-tunnel experiments. For the wet deposition model, the transport equation of a new scalar concentration scavenged by rain droplets is developed and used instead of the scalar concentration scavenged by raindrops falling to the ground surface just below the scavenging point, which is normally used in mesoscale numerical models. A sensitivity analysis of the proposed wet deposition procedure is implemented. The result indicates the applicability of RANS for high-resolution grids considering the effect of terrains on the wet deposition.

• New & Renewable Energy
• /
• v.6 no.4
• /
• pp.50-60
• /
• 2010

With the development of wind industry, rated power of the wind turbine also increases gradually. Accordingly, size of the wind turbine tower is becoming larger. Tower base diameter of the 2MW wind turbine is about 4m. Larger tower is expected for 4MW or 5MW turbines. Due to limitation of transportation, new type of tower with smooth transportation and effective cost is needed. In this work, a hybrid tower consisting of steel and concrete is designed and analyzed. The optimum ratio of steel and concrete of the hybrid tower is calculated as well as the thickness of the concrete part. Different FE analysis including modal analysis, buckling analysis and static analysis are performed to check the design of hybrid tower comparing with the steel tower. Redesign is also expected after various analyses.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.57 no.10
• /
• pp.1738-1743
• /
• 2008

Environmental issue is one of the key factors to industry area using fossil fuels, because it accelerates the global warming. So it is supposed to reduce greenhouse gases around the developed nations of the world at times go. This issue is especially for the power industry. Under this background, MicroGrid system that consists of Distributed Energy Resources (DER) system, such as natural power system (wind, solar) and fuel-cell, co-generation, also known as CHP (Combined heat and power), has been developed greatly during the last 10 years. This paper adopts optimal model using GAMS to develop methods for conducting an integrated assessment of MicroGrid system.

• 한국신재생에너지학회:학술대회논문집
• /
• 2011.11a
• /
• pp.150.2-150.2
• /
• 2011

본 연구에서는 풍력에너지 보급을 위한 신재생에너지정책의 포트폴리오의 구성이라는 최종 목적 하에 먼저 적용 가능 수단 및 주요 쟁점사항에 대하여 고찰해 보았다. 먼저 FIT(Feed in Tariff)와 RPS(Renewable Energy Portfolio) 등 대표적인 신재생에너지 보급 정책들과 선진국 사례들을 중심으로 적용 가능한 그 외의 정책에 대하여 검토해보았다. 또한 이러한 정책을 시행하였을 때 성공여부에 영향을 미칠 수 있는 국내 주요 정책 변수에 대하여 조사해 보고, 향후 예상되는 국내 산업환경변화를 고려하여 장기적 전략수립을 위한 기초 연구를 수행하고자 하였다. 특히 이 과정에서 신재생에너지산업정책에서 공통된 주요 이슈들과 블레이드의 대형화나 해상풍력발전 등 풍력산업에서 차별화되어 나타나는 이슈에 대하여 검토하고 이러한 이슈들을 정책 포트폴리오 구성에 충분히 반영할 수 있도록 함으로써 현실과 동떨어진 정책연구가 되지 않도록 노력하였다. 이러한 연구는 신재생에너지 강국으로 도약하기 위하여 태양광과 풍력산업을 중심으로 다양한 발전전략을 세우고 있는 우리나라에서 풍력발전산업의 활성화를 위한 장기전략 수립에 기여할 수 있는 정책적 함의를 제공할 수 있을 것이다.

• 한국신재생에너지학회:학술대회논문집
• /
• 2008.10a
• /
• pp.369-371
• /
• 2008

Environmental issue is one of the key factors to industry area using fossil fuels, because it accelerates the global warming. So it is supposed to reduce greenhouse gases around the developed nations of the world at times go. This issue is especially for the power industry. Under this background, CHP system that consists of Distributed Energy Resources (DER) system, such as natural power system (wind, solar) and fuel-cell, co-generation, also known as CHP (Combined heat and power), has been developed greatly during the last 10 years. This paper adopts optimal model using GAMS to develop methods for conducting an integrated assessment of MicroGrid system.

• New & Renewable Energy
• /
• v.18 no.4
• /
• pp.38-53
• /
• 2022

T Recently, the government has been promoting the expansion and supply of renewable energy as an alternative for achieving carbon neutrality and the nationally determined contributions by 2030. In 2020, the Ministries of Industry and Environment and the Korea Forest Service collaborated to build a nationwide onshore wind energy siting atlas considering wind resources and forestry and environmental regulations focused on central regulations. In this study, the ordinances of the local governments were analyzed to examine the effects of regional location regulations on the expansion of onshore wind power energy generation facilities, in addition to those of central regulations. A development permit standard survey of 226 urban plan ordinances of the local governments nationwide showed that presently in 2022, 52 municipalities are applying regulations on wind energy generation facilities by ordinances. This is twice more than that in 2018, when renewable energy power generation facility development was difficult. Additionally, the location regulations applied by these ordinances were organized by items and regions, and regulatory characteristics, such as the number and scope, were analyzed by regions. To analyze the spatial distribution characteristics, JeollaNamdo was selected as the case area. A spatial DB was established for regulated areas based on the regional and central regulations, and the spatial distribution characteristics and the regulatory scope were compared and analyzed.

• Journal of the Korean Society of Industry Convergence
• /
• v.27 no.2_1
• /
• pp.269-276
• /
• 2024

Many countries across the world are making efforts beyond reducing CO₂ levels and declaring 'net zero,' which aims to cut greenhouse gas emissions to zero by not emitting any carbon or capturing carbon, by 2050. Hydrogen is considered a key energy source to achieve carbon neutrality goals. Korean companies are also interested in building overseas green ammonia production plants and importing hydrogen into Korea in the form of ammonia. Green hydrogen production uses renewable energy sources such as solar and wind power, but the variability of power production poses challenges in plant design. Therefore, optimization of the configuration of a green ammonia production plant using renewable energy is expected to contribute as basic information for securing the economic feasibility of green ammonia production.

• Journal of the Korean Society of Industry Convergence
• /
• v.27 no.3
• /
• pp.547-553
• /
• 2024

Hydrogen is considered a key energy source to achieve carbon neutrality through the global goal of 'Net Zero'. Due to limitations in domestic green hydrogen production, Korean companies are interested in importing green hydrogen produced overseas. Because Australia and the Middle East possess high-quality renewable energy resources, they are attracting attention as suitable regions for producing green hydrogen using renewable energy. The cost of constructing and operating a green ammonia plant varies depending on the region. In this study, an economic feasibility comparison of green ammonia plant construction in Australia and the Middle East is conducted. Through this, it is expected to contribute to the economic analysis and feasibility analysis of the project to import hydrogen in the form of green ammonia into Korea.

• Journal of the Korean Society of Industry Convergence
• /
• v.26 no.4_2
• /
• pp.715-724
• /
• 2023

Solar energy forecasting is essential for (1) power system planning, management, and operation, requiring accurate predictions. It is crucial for (2) ensuring a continuous and sustainable power supply to customers and (3) optimizing the operation and control of renewable energy systems and the electricity market. Recently, research has been focusing on developing solar energy forecasting models that can provide daily plans for power usage and production and be verified in the electricity market. In these prediction models, various data, including solar energy generation and climate data, are chosen to be utilized in the forecasting process. The most commonly used climate data (such as temperature, relative humidity, precipitation, solar radiation, and wind speed) significantly influence the fluctuations in solar energy generation based on weather conditions. Therefore, this paper proposes a hybrid forecasting model by combining the strengths of the Prophet model and the GRU model, which exhibits excellent predictive performance. The forecasting periods for solar energy generation are tested in short-term (2 days, 7 days) and medium-term (15 days, 30 days) scenarios. The experimental results demonstrate that the proposed approach outperforms the conventional Prophet model by more than twice in terms of Root Mean Square Error (RMSE) and surpasses the modified GRU model by more than 1.5 times, showcasing superior performance.

• Journal of the Korean Society of Industry Convergence
• /
• v.2 no.2
• /
• pp.173-180
• /
• 1999

When Automobile runs high velocity, it causes sleepy velocity profile then that generates lift force and drag force. Lift force reduce tire friction force. Drag force increase consumed power. For improve automobile performance, reduction of Lift force and Drag force was seriously considered. It measured experimently using wind tunnel, numerically using numerical analysis. Finite difference method is using difference equation and simplifed mesh. This method require less calculation time and computer power than other method.