• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 추계학술대회
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• pp.507-510
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• 2006

본 논문은 신재생에너지의 한 분야로서 청정에너지인 소수력 발전시스템 운영시 수용가 부하의 변동에 따른 발전기의 특성변화를 해석한 것이다. 모의에 사용된 동기발전기-전동기가 부하의 변동에 따라 토크, 속도, 전류 등이 어떤 영향을 받는지 전자계 과도해석 프로그램을 사용하여 나타내었다.

• Journal of Electrical Engineering and Technology
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• 제7권6호
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• pp.852-858
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• 2012

This paper describes evaluation results of the wind power penetration limit (WPPL) and the wind energy penetration (WEP) in the Mongolian central power system (MCPS). A wind power plant (WPP) in a power system possesses an output power limit because the power system must maintain a balance between the generation and consumption of electricity at all times in order to achieve an adequate level of quality. The instantaneous penetration limit (IPL) of wind generation at a load is determined as the minimum of the three technical constraints: the minimum output, the ramp rate capability, and the spinning reserve of the conventional generating units. In this paper, a WPPL is defined as the maximum IPL divided by the peak load. A maximal variation rate (VR) of wind power is a major factor in determining the IPL, WPPL, and WEP. This paper analyzes the effects of the maximal VR of wind power on the WPPL, WEP, and capacity factor (CF) in the MCPS. The results indicate that a small VR can facilitate a large amount of wind energy while maintaining a high CF with increased wind power penetration.

• 에너지공학
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• 제21권3호
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• pp.211-220
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• 2012

본 연구에서는 창문을 통한 건물의 에너지손실을 알아보기 위해서 창호시스템의 구조체를 모델링하여 구조체 재질에 따른 열적 손실부분을 분석하였고, 건물에서 창문을 통한 난방부하변화량을 알아보기 위해서 시뮬레이션을 통하여 건물을 모델링하여 창문의 종류와 구조체의 재질에 따른 건물의 에너지 변화량과 온도 변화를 분석하였다.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.789-794
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• 2006

The potential impacts of climate change on heating and cooling energy demand were investigated by means of transient building energy simulations and hourly weather data scenarios for Inchon. Future trends for the 21 st century was assessed based oil climate change scenarios with 7 global climate models(GCMs), We constructed hourly weather data from monthly temperatures and total incident solar radiation ($W/m^2$) and then simulated heating and cooling load by Trnsys 16 for Inchon. For 2004-2080, the selected scenarios made by IPCC foresaw a $3.7-5.8^{\circ}C$rise in mean annual air temperature. In 2004-2080, the annual cooling load for a apartment with internal heat gains increased by 75-165% while the heating load fell by 52-71%. Our analysis showed widely varying shifts in future energy demand depending on the season. Heating costs will significantly decrease whereas more expensive electrical energy will be needed of air conditioning during the summer.

• Earthquakes and Structures
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• 제26권6호
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• pp.449-461
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• 2024

The vertical reinforcement connection between the precast reinforced concrete shear wall and the cast-in-place reinforced concrete member is vital to the performance of shear walls under seismic loading. This paper investigated the structural behavior of three precast reinforced concrete shear walls, with different levels of connection (i.e., full connection, partial connection, and no connection), subjected to quasi-static lateral loading. The specimens were subjected to a constant vertical load, resulting in an axial load ratio of 0.4. The crack pattern, failure modes, load-displacement relationships, ductility, and energy dissipation characteristics are presented and discussed. The resultant seismic performances of the three tested specimens were compared in terms of skeleton curve, load-bearing capacity, stiffness, ductility, energy dissipation capacity, and viscous damping. The seismic performance of the partially connected shear wall was found to be comparable to that of the fully connected shear wall, exhibiting 1.7% and 3.5% higher yield and peak load capacities, 9.2% higher deformability, and similar variation in stiffness, energy dissipation capacity and viscous damping at increasing load levels. In comparison, the seismic performance of the non-connected shear wall was inferior, exhibiting 12.8% and 16.4% lower loads at the yield and peak load stages, 3.6% lower deformability, and significantly lower energy dissipation capacity at lower displacement and lower viscous damping.

• Architectural research
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• 제19권4호
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• pp.89-94
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• 2017

In Korea, it is necessary to improve the performance of buildings with respect to the energy efficiency while improving the quality of occupants' lives through a sustainable built environment. During the design and development process, building projects must have a comprehensive, integrated perspective that seeks to reduce heating, cooling and lighting loads through climate-responsive designs. The aim of this study is to assess the optimal window-to-wall ratio of multi-rise residential units in the early design phase in Korea. The study analyzed the variation of annual heating and cooling energy load in two apartment prototype units located in Seoul city using different WWRs. The analysis was conducted using Autodesk Ecotect Analysis 2011 tool. The study found for total annual building load reductions WWR on the south and north face should be studied independently based on the room function. It also found reducing the WWR for bedrooms and windows on the northern façade resulted in reduced total annual building load.

• International Journal of Air-Conditioning and Refrigeration
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• 제9권1호
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• pp.58-64
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• 2001

This study is to examine the emission quantity of $CO_2$ gas as the environmental load in office buildings. After the investigation of monthly consumption of each energy source(electricity and natural gas), it is analyzed that the $CO_2$ emission quantity of 34 office buildings surveyed is 22.4 kg-c/$m^2$-year, which consists of 17.5 kg-c/$m^2$-year by consurunlelectncif. and 4.9 kg-c/$m^2$-year by consuming natural gas. And the $CO_2$ emission quantity of each load in those buildings consists of 68% emitted by general electricity, 16% by cooling load and 16% by beating load. It is also proposed that the $CO_2$ emission quantity of cooling and heating load is profoundly pertinent to the variation of outdoor temperature.

• 설비공학논문집
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• 제11권2호
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• pp.244-249
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• 1999

This study is to examine the emission rate of $CO_2$gas as the environmental load in office buildings. After the investigation of monthly consumption of each energy source(electricity and natural gas), it is analyzed that the $CO_2$emission rate of 34 office buildings surveyed is 22.4kg-$c/m^2$.year, which consists of 17.5kg-$c/m^2$.year by consuming electricity, and 4.9kg-$c/m^2$.year by consuming natural gas. And the $CO_2$emission rate of each load in those buildings consists of 68% emitted by general electricity, 16% by cooling load and 16% by heating load. It is also proposed that the $CO_2$emission rate of cooling and heating load is profoundly pertinent to the variation of outdoor temperature.

• KIEAE Journal
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• 제10권6호
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• pp.27-32
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• 2010

Approximately 20 percentage of energy consumptions in buildings is consumed as lighting energy. Thus, most of the corporations of lighting fixture have launched low energy products. However, many researchers focused on the only luminous efficacy for energy conservation and used the evaluating tool of study. This can not gauge the precise cooling load related on generated heat of artificial lighting. In order to assess an effect of the temperature variation of lighting resources, the main purpose of this study is to predict the generated heating energy from lighting by measuring the thermal variation in scale model to reduce external noise. Also this paper used MX100 data logger to record at an interval of 1 minute for 60 minutes for the temperature of interior lightings such as incandescent lamp, fluorescent light, halogen lamp and LED lamp. As a result, LED lamp generated the lowest heat. On the other hand, incandescent lamp did the highest.

• 한국지하수토양환경학회지:지하수토양환경
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• 제21권3호
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• pp.64-81
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• 2016

To analyze the influence of various groundwater flow rates (specific discharge) on BHE system with balanced and unbalanced energy loads under assuming same initial temperature (15℃) of ground and groundwater, numerical modeling using FEFLOW was used for this study. When groundwater flow is increased from 1 × 10⁻⁷ to 4 × 10⁻⁷m/s under balanced energy load, the performance of BHE system is improved about 26.7% in summer and 22.7% at winter time in a single BHE case as well as about 12.0~18.6% in summer and 7.6~8.7% in winter time depending on the number of boreholes in the grid, their array type, and bore hole separation in multiple BHE system case. In other words, the performance of BHE system is improved due to lower avT in summer and higher avT in winter time when groundwater flow becomes larger. On the contrary it is decreased owing to higher avT in summer and lower avT in winter time when the numbers of BHEs in an array are increased, Geothermal plume created at down-gradient area by groundwater flow is relatively small in balanced load condition while quite large in unbalanced load condition. Groundwater flow enhances in general the thermal efficiency by transferring heat away from the BHEs. Therefore it is highly required to obtain and to use adequate informations on hydrogeologic characterristics (K, S, hydraulic gradient, seasonal variation of groundwater temperature and water level) along with integrating groundwater flow and also hydrogeothermal properties (thermal conductivity, seasonal variation of ground temperatures etc.) of the relevant area for achieving the optimal design of BHE system.