• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.198.1-198.1
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• 2010

우리나라 남부지방은 대체적으로 태양 일사량이 풍부하여 태양열 시스템의 설치조건으로는 가장 좋은 지역이다. 현재까지 국내에 보급된 태양열 시스템은 외기조건이 불량한 경우에는 비효율적이다. 최근 태양열 온수기는 전국적으로 매우 활발히 보급되고 있고 태양열 온수기에 대한 일반인들의 인식은 그 어느 때보다 높다고 할 수 있다. 태양열이용 열펌프시스템 기술은 소형 온수기에의 적용 뿐 아니라 건물의 난방기술에도 적용되고 있다. 본 연구에서는 태양열 집열기 직접 팽창식 열펌프시스템(이하 '태양열 시스템')의 열성능 효율 향상에 가장 많이 기여하는 팽창장치와 롤본드형 태양열집열기에 대하여 실험하였고 현장 적용가능성을 분석하였다. 또한 태양열 열펌프식 온수 및 난방시스템의 한국의 남부지방에서의 적용가능성은 지난 관련연구결과를 분석하여 비교하여 모색하였다.

• International Journal of Air-Conditioning and Refrigeration
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• 제12권4호
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• pp.206-213
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• 2004

Cycle test for developed phase change material (PCM) is necessary in order to assess the variation of latent heat, which decreases with time by deterioration. T-history method and measurement using heat-flux meter are appropriate for the cycle test in a tube filled with PCM because they do not need an extraction of sample in measuring heat of fusion. In the present study, these methods were applied to a PCM having a melting point below a room temperature, different to the past studies for PCMs melting above a room temperature. As a result of experiment using pure water as specimen, we can obtained rea-sonable values for heat of fusion.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 1995년도 춘계학술발표회 초록집
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• pp.213-222
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• 1995

Korean traditional Ondol with the sensible heat storage medium has been for a long time used as residential heating system, in these days the concrete Ondol without the heat storage medium was realized as the heating system in the private houses and the apartments. This floor heating system is good for our health. But the concrete Ondol is not desirable for the energy saving and for the maintenance of comfortable room temperature because the heat storage medium is not employed in the concrete Ondol. And as the hot water circulating pipes ate buried under the the concrete floor, the concrete Ondol system has some kind of problems to be improved. Therefore the new type of Ondol system was developed in this study. And the new Ondol was consisted of latent heat storage material as heat storage medium with a great heat capacity and bioceramics as medium to maintain comfortable room temperature. In this study, the heat transfer characteristics of latent heat storage-bioceramic Ondol was analyzed theoretically.

• 설비공학논문집
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• 제15권7호
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• pp.604-610
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• 2003

Cycle test for developed phase change material (PCM) is necessary in order to analyze the variation of latent heat, which decreases with time by deterioration. 7-history method and measurement using heat flux meter are appropriate for the cycle test in a tube filled with PCM because they do not need an extraction of sample in measuring the heat of fusion. In the present study, these methods were applied to a PCM having a melting point below a room temperature, different from the past studies for PCMs melting above a room temperature. As a result of experiment using pure water as specimen, we can obtain reason-able values for heat of fusion by both methods.

• 한국태양에너지학회 논문집
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• 제27권4호
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• pp.67-75
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• 2007

This study intends to the adequacy inspection of the room temperature variation rate that is available in the building heat performance evaluation index, so we performed the sensitivity analysis about the room temperature variation rate and the energy consumption in the room. For these purpose, we supposed the models which are composed of the various window area, insulation thickness and ventilation rate. Then we analyzed the simulation using the ESP-r and Seoul weather data. In this research, the pattern of the increasing & decreasing rate of annual load according to the change of the various design factors is similar to the pattern of increasing & decreasing rate of not the K-values but the room temperature variation rate. Also we derive the optimum value of the various design factors and the room temperature variation rate in this analysis model. Further study is to be required the development of convenient tool to use in the real design.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 정기총회 및 창립40주년기념 학술대회 학회본부
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• pp.293-295
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• 1987

This paper deals with the dielectric properties dielectric breakdown strength and mechanical tensile properties according to heat - treatment condition of polyurethane resin. This resin is heat - treated over a range of temperature from $50^{\circ}C$ to $150^{\circ}C$. It is shown that the dielectric dissipation factor decreases with increase of heat - treatment temperature of the sample exept for the sample heat - treated at $150^{\circ}C$. The maximum dielectric breakdown strength is appeared for the sample heat - treated for 10 hours at $100^{\circ}C$, after curing for 24 hours at room temperature. The optimal heat - treatment condition in the view point of the electrical and mechanical properties is appeared for the sample heat - treated for 10 hours at $100^{\circ}C$, after curing for 24 hours at room temperature.

• 설비공학논문집
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• 제18권4호
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• pp.287-296
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• 2006

In this paper, optimal control strategy of the air-conditioning system with slab thermal storage was investigated based on the optimal control theory. An optimal heat output to the plenum chamber and the air-conditioned room was determined based on two kinds of criterion functions. The first one requires small deviation in room air temperature from a set-point value and low energy consumption. It is shown that the optimized control is to store heat through the whole storage time and to increase storage rate gradually with time. As the second case, a criterion that both a deviation of operative temperature from a set-point temperature and the energy consumption should be minimized was adopted. The room air temperature was a little high and the cooling load during storage time was reduced, compared with the results when a criterion function considering only the room air temperature is used.

• 설비공학논문집
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• 제18권11호
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• pp.896-905
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• 2006

An optimal control of an air-conditioning system with slab thermal storage is investigated by making use of the Maximum Principle. An optimal heat input to a plenum chamber and an air-conditioned room is determined by minimizing a criterion function which is given as integral sum of two terms. The first term is the square of the deviation in the room air temperature from the set-point value, and the second is the absolute value of the heat input. The result indicates that it tries to keep a room air temperature in set-point value by heating as much as possible at the time of a setup of a room air temperature or just before that, in order to avoid a heat loss arising at the time of the non-air conditioning. The result is compared with that of the case when the square of the heat input is used as a criterion.

• 한국화재소방학회논문지
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• 제26권1호
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• pp.16-22
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• 2012

화재시험에 있어서 정확한 발열량의 측정은 시험체의 화재 안정성을 결정하기 위한 중요한 정보이다. 발열량 측정값은 측정 인자들의 오차에 기인하여 영향을 받는다. 본 연구에서는 한국철도기술연구원에 설치된 룸코너 시험기에 대한 불확도의 인자를 분석하였고 이를 이용하여 KTX 내장재 화재시험의 발열량 측정 불확도를 계산하였다. 화재 발열량 불확도 계산 결과, 화재시작단계에서 불확도가 매우 높은 값으로 나타났고 화재가 성장하면서 불확도는 점차적으로 감소하였다. 불확도 인자들 중 산소 농도가 발열량 측정 불확도에 가장 크게 기여하는 것으로 나타냈다.

• International Journal of Air-Conditioning and Refrigeration
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• 제12권4호
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• pp.184-191
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• 2004

In order to improve the performance of a 2 room heat pump with a constant speed compressor, the optimum refrigeration circuit of the heat pump with different cooling and heating capacities is developed by applying capillary tubes. The refrigeration circuit is composed of four parts; a heating circuit, a cooling circuit, a by-pass circuit and a balance circuit. The performance of the 2 room heat pump are investigated from a rating experiment and a reliability experiment, using the calorimeter. Results of the rating experiment show that the capacity of heat pump is about $93\%$ of the design value. In particular, the capacity of the cooling single operation is about $13\%$ higher than the design value, and the capacity of the heating multi operation is about $5\%$ higher than the design value. From the reliability experi-ment, it is found that the lowest driving voltage of the compressor is about $75\%$ of the rating voltage. Also the compressor is reoperated normally under the flood back and the over load.