• 한국태양에너지학회 논문집
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• 제32권6호
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• pp.60-67
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• 2012

Government Geothermal Cooling-Heating Projects has made efforts to reduce GHG(Greenhouse Gas) emissions and to manage cost of greenhouse farm households. This study evaluated the economic benefits of heating load rate of change by comparing Geothermal Cooling-Heating System with the existing system(greenhouse diesel heating) in the Government Geothermal Cooling-Heating Projects. Economic analysis results shows that, 1) When installing the Cooling-Heating system according to the ratio of 70% heating load in policy standards, the geothermal cooling-heating system has economic efficiency with greenhouse type or scale independent because the investment cost is recovered within 7 years. And It was more economic efficiency the ratio of 50% heating load than70% heating load. 2) When installing the Cooling-Heating system according to the glass greenhouse of the ratio of 90% heating load, pay period of investment cost is recovered within 5 years. Therefore it is necessary to apply flexible heating sharing according to greenhouse type or scale.

• 감성과학
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• 제18권3호
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• pp.93-106
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• 2015

최근 고기능성 제품에 대한 수요가 증가함에 따라 ICT 기능과의 융합을 통한 스마트 의류는 일상생활 분야로 확대되고 있다. 그 중 하나로, 발열 텍스타일 및 제어 모듈을 통해 의복 내 발열기능을 조절하는 스마트 의류에 대한 관심이 높아지고 있으며, 발열 기능을 갖는 스마트 의류의 시장 전망이 높아지고 있으나, 발열 패드 부착위치에 따른 발열 기능의 효용성 및 온열감에 대한 연구는 부족한 실정이다. 본 연구에서는 발열 패드의 위치에 따른 피부온의 변화와 온열감에 대한 실증적 연구를 통하여 발열기능의 스마트 의류 개발을 위한 최적의 발열 위치를 도출하고자 하였다. 이를 위하여 20대 표준체형의 남성 10명을 피험자로 선정하였으며, 영하 $5^{\circ}C$의 인공기후실에서 20분의 안정기, 20분의 처치기, 40분의 회복기를 통해 11군데에서의 피부온, 직장온과 주관적 온열감을 측정, 평가하였다. 최종적으로, 발열패드를 위한 최적의 위치를 도출하고 제시하였다.

• 한국식생활문화학회지
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• 제15권2호
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• pp.95-100
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• 2000

This study was attempt to improve the quality of rapid- and low salt-fermented liquefaction of sardine (Sardinops melanoslicta). Effect of pretreatment methods such as water adding, heating, and intermittent NaCl adding on fermented liquefaction of chopped whole sardine were investigated. The divisions of the experimental samples by pretreatment methods were as follows; Sample A (water adding and heating): chopped whole sardine adding 20% water and then adding 3 and 5% NaCl consecutively at the intervals of 3 and 6 hrs during heating for 9 hrs at $50^{\circ}C$ and then fermented at $33^{\circ}C$ for 90 days. Sample B (preheating): chopped whole sardine with 8% NaCl and heating at $50^{\circ}C$ for 9 hrs and then fermented at $33^{\circ}C$ for 90 days. Sample C (control): neither pretreatment methods of water adding nor preheating on chopped whole sardine with 13% NaCl and then fermented at $33^{\circ}C$ for 90 days. Comparison of the appropriate fermentation period, yield of hydrolysate, chemical composition of fermented liquefied products were carried out. The highest content of amino nitrogen appeared at 60 days in the sample A, 75 days in the sample B, and 90 days in the sample C during the fermentation period. The appropriate fermentation period of the sample A was shorten 15 days than the sample B and 30 days than the sample C in the processing of sardine. The product A was lower NaCl (8.5%) and lower histamine content (25mg/100g) than the sample B and C. Possibly, three kinds of pretreatment methods such as water adding, heating, and intermittent NaCl adding, might be recommend as the processing of rapid- and low salt-fermented liquefaction product of chopped whole sardine.

• Journal of Information Display
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• 제10권2호
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• pp.76-79
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• 2009

In Joule-heating-induced crystallization, solid-to-solid or liquid-to-solid phase transformation could occur. It was found that novel physical phenomena that randomly nucleated liquid seeds, followed by rapid solidification in an amorphous matrix, during the Joule-heating-up period play an important role especially in liquid-to-solid transformation. Under some processing conditions, super-grains sized 6-8 ${\um}m$ were produced by the lateral growth from the initial seeds, without any artificially control.

• KIEAE Journal
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• 제6권2호
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• pp.43-50
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• 2006

A Double Facade System(DFS) is well known as an innovative solution of ecological facade in the west european countries. There are more than 200 various realized DFS in Germany. At the same time, the korean engineers have researched to find out the physical advantages of DFS in the moderate korean climate, which has a very humid summer with high temperature and a dry winter with low temperature. For example, the monthly mean temperature in Korea comes up to 28K, while that in Germany comes up to only 19K. That is, why a other solution of DFS is needed in Korea. This study has experimented the physical performance of the natural ventilation in the heating period. The preheating function of the cold air by DFS can improve no doubt the performance of the natural ventilation at the cold season as well as spring and autumn. The physical difference between single and double facade on natural ventilation has been tested at the newly constructed laboratory, which can turn $360^{\circ}$ to confirm the characteristic of a facade with the various directions. The results show the natural ventilation of the DFS has definitely much more comfortable than that of the single facade system. The air velocity of the inflow as well as the air temperature in the DFS provide a more stable condition than in the SFS. The theoretical limit(air velocity max 0.2m/s, air temperature min. $18^{\circ}C$, temperature difference between 100mm and 1700mm height max. 3K) on the indoor comfortableness doesn't go over in the DFS. On the other hand, the SFS showed an unstable condition with an excess of comfortableness limit on air velocity as well as temperature. In view of the researching results so far achieved, the research came to a conclusion, that the DFS can provide a more comfortable indoor condition by the preheating in the heating period than a SFS, and the period of natural ventilation in winter time could be definitely increased at the DFS.

• Architectural research
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• 제14권1호
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• pp.11-18
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• 2012

College of Architecture, Georgia Institute of Technology, Atlanta, GA, US Abstract The intermittent heating and cooling energy need calculation of the ISO 13790 monthly method was examined. The current ISO 13790 method applies a reduction factor to the continuous heating and cooling need calculation result to derive the intermittent heating and cooling for each month. This paper proposes a method for the intermittent energy need calculation based on the internal mean temperature calculation. The internal temperature calculation procedure was introduced considering the heat-balance taking into account of heat gain, heat loss, and thermal inertia for reduced heating and cooling period. Then, the calculated internal mean temperature was used for the intermittent heating and cooling energy need calculation. The calculation results from the proposed method were compared to the current ISO 13790 method and validated with a dynamic simulation using EnergyPlus. The study indicates that the intermittent heating and cooling energy need calculation method using the proposed model improves transparency of the current ISO 13790 method and draws more rational outcomes in the monthly heating and cooling energy need calculation.

• 한국주거학회논문집
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• 제2권2호
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• pp.35-40
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• 1991

In this study, the operation(heating) period of heat source(boiler) machineries in apartment building for periodic heat load analysis has been established by investigating their heat source machineries actural operation period, energy consumption, the capacity of heat source machineries, and their building element. Thus, the purpose of this paper is at bring up the various pre-estimate expression for energy conservatiove, efficient operation and amount of water supplied.

• 한국환경과학회지
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• 제30권3호
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• pp.245-255
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• 2021

In this study, we evaluated the effect of the type of sewage sludge (digested, non digested) on drying efficiency according to the polymer injection rate. The drying characteristics were shown using a near-infrared ray (NIR) and a microwave. As a result of the drying characteristics with NIR at a polymer dose ratio of 8%, the heating up period is up to 6 minutes after the start of the drying experiment. Afterwards, the constant rate drying period of the digested sludge (A, C and G sites) was 6 minute → 18 minute, showing a rapid decrease in moisture. On the other hand, non digested sludge (B, D, E, F, H, I, J and K sites) showed gradual drying characteristics compared to digested sludge until complete drying (10%). As the polymer dose ratio of 10% and 12%, the heating up period for digested sludge is up to 6 minute after the start of the experiment. Afterwards, the constant rate drying period of the digested sludge was 6 minute → 20 minute, showing a rapid decrease in moisture. On the other hand, the heating up period of non digested sludge was up to 10 minute after the start of the experiment, and the constant rate drying period was 10 minute → 22 minute, which was shorter than digested sludge. As a result of the drying characteristics with microwave at a polymer dose ratio of 8%, 10% and 12%, the constant rate drying period the digested sludge was 4 minute → 20~22 minute, showing a rapid decrease in moisture. On the other hand, non digested sludge of the constant rate drying period was 4 minute → 22~30 minute, which was longer than digested sludge.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.670-674
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• 1997

Semi-solid forging is a compound forging technology to deventional forging process. Among several steps of semi-solid forging process, the heating step of a billet prior to semi-solid forging step is necessarily required to obtain globular microstructure. For the forming operation to work properly, it is also important to heat the billet uniformly for the uniformity of solid-liquid distribution. To satisfy these requirements, induction heating has been generally used for a long time. This paper presents the method to find heating condition and the temperature distribution inside of a billet with a induction heating apparatus by comparing the computer simulation with experiment for aluminum alloys Al2024 and A356.

• 한국정밀공학회지
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• 제14권8호
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• pp.15-20
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• 1997

Semi-solid forging is a compound forging technology to develop conventional forging process. Among several steps of semi-solid forging process, the heating step of a billet prior to semi-solid forging step is necessarily required to obtain globular microstructure. For the forming operation to work properly, it is also important to heat the billet uniformly for the uniformity of solid-liquid distribution. To satisfy these requirements, induction heating has been generally used for a long time. This paper presents the method to find heating condition and the temperature distribution inside a billet with a induction heating apparatus by comparing the computer simulation with experiment for aluminium alloys A12024 and A356.