• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.643-649
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• 2008

The purpose of this study is to establish a standard for unit cooling load in central control type apartment applied district cooling. The model of unit household was selected. And the standard of coefficient of overall heat transmission, location of unit household, indoor air temperature, solar radiation & thermal conduction at window and interior load was selected, and region, expansion or non-expansion of balcony, pyeong type, azimuth, rate of window area was applied as parameter. And then cooling load simulation was performed. Based on the result of simulation, the synthetic district cooling load was presented for selecting heat source of apartment applied district cooling, and unit cooling load was analyzed according to design parameter.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.1007-1012
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• 2008

Demand for the highly efficient and high performance urban energy supply system having been continuously increased according to the rise of quality of life and continuously increased energy cost all over the world. The district heating and cooling system is very effective way for energy saving, cost reduction, and demand side management of energy. There are several district cooling supply technologies such as chilled water direct transportation, installation of absorption type chiller in the user side, and desiccant cooling. This study investigates the advantage and technical problems of each district cooling technology. Also, it is necessary political and financial support system for the extension of district cooling system.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.233-238
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• 2006

A new district cooling system using ice slurry for the uncertain cooling load of the future is presented. The chilled water produced by the absorption chillers is used for the base cooling load. The temperature of the chilled water is reduced by mixing of ice slurry depending on increasing of the cooling load. Finally, IPF of the ice slurry is increased up to 10% at the peak load. The transporting mass flow rate is decreased down to 44.7%, and the diameter of the main pipe is decreased down to 66.7%, but the diameter of the branched pipe is designed as the same size of the chilled water.

• 설비공학논문집
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• 제18권10호
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• pp.776-782
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• 2006

A new district cooling system using ice slurry for the uncertain cooling load of the future is presented. The chilled water produced by the absorption chillers is used for the base cooling load. The temperature of the chilled water is reduced by mixing of ice slurry depending on increasing of the cooling load. Finally, IF of the ice slurry is increased up to 10% at the peak load. The transporting mass flow rate is decreased down to 44.7%, and the diameter of the main pipe is decreased down to 66.7%, but the diameter of the branched pipe is designed as the same size of the chilled water.

• 한국조경학회지
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• 제27권2호
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• pp.19-28
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• 1999

This study quantified shading, evapotranspiration and windspeed-reduction effects of trees on use and cost of heating and cooling energy in two residential neighborhoods of Chuncheon different in tree cover. Annual savings per residence of heating energy were approximately 1,210 MJ(1%) and those of cooling energy, 130 kWh(10%) in study district 1 having tree cover of about 10% . For district 2 with tree cover of about 20%, annual heating and cooling savings were 2,130 MJ(2%) and 180 kWh(19%) per residence, respectively. Trees annually saved energy costs by approximately ￦31,000 ($26, $1=￦1,200) per residence in district 1 and by ￦49,000($41) in district 2. One tree taller than 3 m resulted in annual energy savings of ￦8,000($7) in the study districts. Energy savings by trees in district 2, which had higher tree cover by 10% difference than district 1, were about 2 times greater than those in district 1. This implies that more tree plantings could enhance energy saving effects. Of the total costs saved, 58% was attributed to windspeed reduction and 47%, evapotranspiration. However, shading increased energy costs by 5% due to tree plantings at the wrong locations. Full tree plantings on the west and north of buildings and avoidance of shade-tree plantings of use of solar-friendly trees on the south are recommended to increase building energy savings efficiently.

• 생물환경조절학회지
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• 제3권1호
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• pp.36-41
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• 1994

본 시험의 목적은 온실의 주년계획이용을 위해서 하기주간 냉방의 방법으로 heat pump를 이용한 냉수냉방과세무냉방의 효율성을 검사했고 하기 토마토 배꼽썩음병 발생을 억제하기 위하여 냉방과 함께 과실에 송풍처리와 식물체 전체의 공기유동을 촉진시켜주는 처리를 했다. 시험결과는 다음과 같다. 1) 냉수냉방구간 기온은 13시경 온실내 기온보다 약 1$0^{\circ}C$이상 낮았고, 세무냉방구간 하부의 기온은 13시경 온실내 기온보다 약 5$^{\circ}C$ 낮았다. 2) 과실에 송풍처리는 냉방방법에 상관없이 배꼽썩음병이 방지됐고, 냉수냉방 무송풍구의 배꼽썩음병 발생율은 34.5%, 세무냉방 무송풍구는 54.5%, 세무순환냉방구는 78%였다. 냉방효율면에서는 냉수냉방 방법이 충분히 생육한계온도 이하로 냉각되었고, 배꼽썩음병 발생율에서도 세무냉방보다 낮았다. 세무냉방은 재배구간의 공기를 유동시킴으로서 약 24%증가했다. 그러므로 토마토 배꼽썩음병 발생에 관한 환경요인은 온도보다는 습도가 밀접한 관계가 있는 것으로 생각되어진다.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 춘계학술발표대회 논문집
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• pp.179-184
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• 2011

The development of new energy has attracted consideration attention due to the high oil price and environmental problems. In advanced country, they have tried to carry out a long range plan for energy. We need to develop new energy for Low Carbon Green Growth in Korea. The building is 30% among ratio of energy consumption in Korea. And in the past, heating energy was high ratio for energy using at home. But recently, the demand for cooling energy keeps growing due to rising average temperature on the earth and improvement of life quality. In this situation, the energy of lake water and ocean water has studied to utilize in advanced country because of low temperature at underwater. But the study for deep water is still a lot left to do. In this study, we analyzed district cooling system and the present condition. Analyzing the deep lake water cooling system in Toronto, we found an application of district cooling system using deep ocean water. Deep lake water uses heat source for district cooling and water source for city in Toronto. So reducing the initial cost, this city had economic effect. When DLWC was applied at existing building, the heat exchanger was installed instead of cooling tower and refrigerator. And the heat exchanger used to connect main pipe with cool water on city. System using deep ocean water can be applied as a similar way to supply cool water from lake to building.

• 설비공학논문집
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• 제12권3호
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• pp.251-257
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• 2000

District heating and cooling systems offer highly efficient energy utilization and maintenance by centralizing heat management. More pumping power, however, is required because the water has to travel long distance from heat source to the users. In the present study, a trace of drag reduction additives is added to the District Cooling system to achieve a significant drag reduction and save pumping power. Water-soluble polymers, surfactants, and environment-friendly degradable polymers are used as effective drag reducing additives. Time dependent percent drag reductions are compared for various additive solutions at 100 wppm concentration for different water velocity. Without as an anionic surfactant, copolymer was most effective in percent drag reduction. It is found that there exists an optimal condition when copolymer is mixed with SDS. An environment-friendly degradable polymer, xanthan gum, is found to be a significant drag reduction additive. Ice slurry systems, can give less pressure drops compared with chilled water system for certain condtions. Drag reduction additives were also effective for the ice slurry system.

• 한국가스학회지
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• 제10권4호
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• pp.34-40
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• 2006

본 논문은 지역집단 냉방에너지 공급시스템과 환경보호정책에 관한 융합기술을 에너지절약과 미이용 에너지인 냉열자원의 활용성을 함께 다루고 있다. 지역집단 냉 난방 시스템은 에너지를 절약하고, 비용을 절감하며, 안전성을 확보할 수 있는 효과적인 기술이다. 에너지가 생활수준의 향상에 긍정적인 영향을 주기 위해서는 에너지 절약과 환경보호정책을 균형감 있게 고려해야 한다. 냉열에너지는 LNG를 기화하는 과정에서 생산할 수 있지만, 바다의 심층수와 빙축열에서도 얻을 수 있다. 지역집단 냉방에너지는 아파트, 사무실, 공장설비 등에 냉열공급 파이프라인을 통하여 공급하게 된다. LNG 냉열에너지는 전기에너지와 냉매를 사용하여 작동하는 기존의 에어컨 시스템을 대체할 수 있는 경쟁력 높은 에너지이다. 청정에너지이고 운전비용을 줄이는 것으로 알려진 LNG 냉열은 $CO_2$와 같은 대기오염원과 자연환경에 유해한 냉매방출을 방지할 수 있다. 본 연구에서는 LNG 냉열에너지의 사용과 에너지 절약, 그리고 환경보존에 중요한 영향을 미치는 융합기술에 대한 유익한 정보를 제공한다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.433-437
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• 2005

This study was carried out the design and analysis of solar thermal system with preheating of returning district heating water for the Chung-ju district heating and cooling system. Two different types of solar collectors are used for this system. TRNSYS simulation program was used for the analysis. As a results, the solar system efficiency is $35.8\%$ for the plate type and $45.1\%$ for the evacuated type solar collector in the case of $50^{\circ}C$ for the returning district heating water temperature. The returning district heating water temperature is on of the very important factors that is influence on the system efficiency. So the effect of the returning district heating water temperature on the system efficiency is analyzed in this study.