• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.3446-3451
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• 2007

The thermal behavior of a building in response to heat input from an active solar space heating system is analysed to determine the effect of the variable storage tank temperature on the cycling rate, on and off temperature of a heating cycle and on the comfort characteristics of room air temperature. A computer simulation of the system behavior has been performed and verified by comparisons with various parameters. Especially, this study is focused on the effect of the system's performance when subjected to dynamic cooling loads. The heat input to the absorption system is provided by an array of solar collectors that coupled to a thermal storage tank.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 춘계학술발표대회 논문집
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• pp.155-161
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• 2009

Desiccant systems have been proposed as energy saving alternatives to vapor compression air conditioning for handling the latent load. Use of liquid desiccants offers several design and performance advantages over solid desiccants, especially when solar energy is used for regeneration. The liquid desiccants contact the gas inside the packed column and the heat transfer and mass transfer will occur. This proposal is try study the mass transfer and heat transfer inside the packed column of dehumidifier and regenerator systems. And later on, the rates of dehumidification and regeneration that were affected by desiccant flow rates, air temperature and humidity, and desiccant temperature and all that variation will influence the performance of the systems.

• 한국태양에너지학회 논문집
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• 제21권3호
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• pp.61-68
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• 2001

This study represents numerical analysis on the thermal and fluid flow of the air layer in a solar collector. The boundary conditions was assumed that the top and bottom wall of the air layer have a heating and cooling surface, respectively, and this calculation model have a solid body with a cooling temperature of $20^{\circ}C$. As the results of simulations, the magnitudes of the velocity vectors and isotherms are increased proportionally to the tilt angles. As the tilt angle is increased, the mean Nusselt numbers are increased and the maximum value of the mean Nusselt number was appeared at tilt angle $\theta=75^{\circ}$.

• 한국태양에너지학회 논문집
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• 제34권3호
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• pp.89-97
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• 2014

Recently design standard for energy-saving in apartment buildings has been consolidated gradually on the basis of evaluation and certification standards of energy efficiency of buildings, the energy-saving policy of building at home and abroad. Performance criteria for thennal insulation as well as fenestration has been progressively enhanced, and performance criteria for ventilation and airtightness of the building have also been re-developed. Therefore, heating and cooling load characteristics of the apartment building can be changed. For the design of the upcoming heating and cooling equipment in apartment buildings, it is necessary to evaluate the heating and cooling load characteristics according to the design strategies for energy saving in apartment buildings. As a result, in this study, it is intended to use as a resource for analyzing the impact that the adoption of energy-saving design variables for each of the apartment buildings, to predict the heating and cooling load characteristics in the apartment building.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.64.1-64.1
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• 2010

In this study, the energy and economic analysis of KIER Zero Energy Solar House (KIER ZeSH) was carried out. KIER ZeSH was designed and constructed in the end of 2009 for the purpose of more than 70% energy self-sufficiency in total load as well as less than 20% of additional construction cost. The several building energy conservation technologies like as super insulation, high performance window, wast heat recovery system, etc and renewable energy system. The renewable heating and cooling system is a kind of solar thermal system combined with geo-source heat pump as a back-up device. The capacity of 3.15kW solar BIPV system was also installed on the roof. The measurement by monitering system of ZeSH was conducted for one year from November 2009 to October 2010. The energy self-sufficiency and economic analysis were conducted based on the this monitering result. As a result, the energy self sufficiency is about 83% which is higher than that of the target and the payback period is 11 years.

• 설비공학논문집
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• 제26권10호
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• pp.481-485
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• 2014

Low solar gain glazing should be applied on windows in order to reduce the solar radiation load. In a country where a cooling and a heating load coexist throughout the year, such as in Korea, a high solar gain glazing is need to reduce the heating load, but a low solar gain glazing should be applied to reduce the cooling load. Recently, dynamic windows have been developed for which the solar shading performance switches according to the amount of solar radiation flowing into the indoor space through the glazing, and these have been used in building to solve such problems. The purpose of this research is to analyze the energy performance of the electrochromic glazing for dynamic windows that has been extensively commercialized for office buildings in Incheon and Ulsan through an energy simulation implemented in the eQUEST program.

• 태양에너지
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• 제15권3호
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• pp.59-73
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• 1995

원활한 전력공급을 위해 지중송전케이블에서 발생된 열을 제거하기 위한 방법으로 전력구트라프간접수냉방식이 적용된 지중송전계통에 대한 각 주요 구성요소의 열해석을 수행하였다. 열해석을 수행한 결과, 주어진 조건에서 냉동기가 채택된 냉동장치에서는 냉각수유량은 $2{\sim}3{\ell}/s/pipe$, 팬에 의한 풍속은 $1{\sim}2m/s/fan$인 경우에 지중송전계통의 원활한 전력공급을 위한 냉각계통의 최적조건으로 계산되었다. 반면에 냉각탑만을 설치한 경우에는 냉각수유량 및 풍속이 각각 $2{\sim}3s/pipe$ 및 6 m/s/fan이 최적조건으로 계산되었다. 그러나 냉각탑만이 설치된 경우에는 풍속이 너무 커져서 용량이 큰 팬의 설치 및 전력구내에서 작업자의 작업조건에 적합하지 않다. 따라서 본 연구의 주어진 조건하에서 지중송전계통의 냉동계통은 냉동기가 설치된 냉동장치가 바람직하다.

• 한국태양에너지학회 논문집
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• 제40권1호
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• pp.25-33
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• 2020

It has been reported about the energy saving performance of UFAD(under floor air distribution) system and NPC(night purge cooling) system respectively which are applied for commercial buildings. However, when two systems are used at the same time, the effect of heat transfer from floor plenum to slab may vary depending on the operating conditions of NPC. In this study, cooling energy demands were analyzed for building models with UFAD and NPC by using TRNSYS 17 program. UFAD was applied as a cooling system of the base building model, and the cooling energy demands were compared for 64 cases in which the operating time, supply airflow rate, and outdoor air temperature(T_o) of NPC. As a result, it was confirmed that the cooling energy demands were reduced to 30 ~ 80% level compared to UFAD alone, and in particular, the energy demand was reduced in proportion to the supply airflow rate or the operating time while T_o was 16 ~ 20℃. However, when T_o was 22℃, the increase in the supply airflow rate or the operating time results in a disadvantage in terms of cooling energy demands. In addition, the cooling energy demands for UFAD+NPC model were analyzed by applying weather data from three regions with different average outdoor air temperatures. As a result, the cooling energy demand of operating NPC only when T_o was below 20℃ was reduced by 27% compared to that of operating NPC continuously for 8 hours.

• Current Photovoltaic Research
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• 제6권2호
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• pp.49-55
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• 2018

Recently solar cell industry needs the optimal design of Czochralski process for low cost high quality silicon mono crystalline ingot. Because market needs both high efficient solar cell and similar cost with multi-crystalline Si ingot. For cost reduction in Czochralski process, first of all energy reduction should be completed because Czochralski process is high energy consumption process. For this purpose we studied optimal water-cooling tube design and simultaneously we also check the quality of ingot with Von mises stress and V(pull speed of ingot)/G(temperature gradient to the crystallization) values. At this research we used $CG-Sim^{(R)}$ S/W package and finally we got improved water-cooling tube design than normally used process in present industry. The optimal water-cooling tube length should be 200mm. The result will be adopted at real industry.

• 한국태양에너지학회 논문집
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• 제37권1호
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• pp.71-80
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• 2017

A Data center houses a large number of server computers, storage and etc in racks. With the rapid increase of heat generation rates per rack in a data center, energy consumption rates for cooling have been increased year by year. In this study, energy conservation effects of a MOA (multi-stage outdoor air enabled) cooling system in a data center has been investigated when it is applied to 5 different locations, Korea. As results, Energy conservation effects of the MOA cooling system was achieved at about 20% to 30%. Humidifier operation time was 40 to 55 days when supply air temperature was maintained at 13, and humidity condition was kept within the allowed range even though humidifier was off. Furthermore, humidification was not needed when supply air temperature was maintained at $25^{\circ}C$. In selected 5 locations in Korea, the difference of regional climatic conditions affected no more than 5% in cooling energy consumption rates.