외기냉수냉방 시스템의 에너지 절약효과에 관한 연구

김세훈,이언구,최윤경,원종연 대한건축학회 2006 대한건축학회논문집 Vol.22 No.2

Recently the cooling load in buildings is increasing even in winter. Free cooling can be a very energy efficient way for buildings that are high in cooling load all year round. In this research economical aspects of free cooling and problems of operation were studied through surveys of buildings that need all year round cooling load. Through TRNSYS simulation program, energy using patterns of free cooling system combined with other cooling systems are compared and energy saving effects of free cooling system are reviewed. Also energy conservation variables that effects the building energy cost were set and analyzed. The results are as follows, 1) Energy savings are high in December to March. 2) It is desirable to apply Free Cooling system to where the continuous inside heat gain is occurred. 3) Free Cooling system can be operated efficiently when web bulb temperature of outside air is below 8℃. If systems can be operated with automatic control system, Free cooling system can save more energy. 4) Using lower approach temperature in heat exchanger is suitable for saving energy.

건물용도별 냉방에너지 소비량 차이에 관한 연구

김기중,이창효 서울연구원 2019 서울도시연구 Vol.20 No.2

이 연구의 목적은 건물용도별 단위면적당 냉방에너지소비량 차이와 영향요인의 차이를 실증 분석하는 것이다. 연구의 공간적인 범위는 서울시내 필지 65,729개이며, 시간적 범위는 2015년 8월로 설정하였다. 크리스칼-왈리스 검증을 이용하여 건물용도별 냉방에너지 소비량 차이를 분석하고, 감마회귀분석을 활용해 건물용도별 냉방에너지 소비량 영향력 차이를 분석하였다. 분석 결과, 공동주택과 근린생활시설, 판매업무시설의 냉방에너지소비량은 통계적으로 차이가 있는 것으로 밝혀졌다. 건물에너지 소비 영향요인 측면에서 볼 때, 모든 건물용도에서 공시지가는 냉방에너지 소비를 늘리는 요인으로 분석됐다. 공동주택의 냉방에너지는 주변환경 특성보다 물리적 요인에 영향을 크게 받는 반면, 근린생활시설의 냉방에너지는 물리적 요인보다 주변환경 특성의 영향을 많이 받았다. The purpose of this study is to analyze the difference of cooling energy consumption according to building use. The spatial scope of the study was 65,729 parcels in Seoul, and the time range was August 2015. We analyzed the difference of cooling energy consumption by building use by using Kruskal-Wallis test. Furthermore, this study found the difference in factors affecting cooling energy consumption by building use using gamma regression. As a result of analysis, cooling energy consumption of apartment, neighborhood facility, and sales/work facility is statistically different. Regarding influencing factors of building energy consumption, the factor that increases the cooling energy consumption for all buildings is the land price. The cooling energy of the apartment is more affected by the physical factors than the characteristics of the surrounding environment. In contrast, cooling energy of neighborhood facilities is more influenced by environmental characteristics than physical factors.

건물의 냉각탑 제어 변경에 따른 연간 냉방 에너지 사용량 절감에 관한 연구

하주완,박경순,김환용,송영학 한국건축친환경설비학회 2019 한국건축친환경설비학회 논문집 Vol.13 No.6

The purpose of this study is to find out the efficiency improvement of the cooling system and cut-off of cooling energy consumption by changing the design method of the cooling tower system applied in Korea. The quantitative analysis was carried out on the cooling energy consumption saved by changing the Korea Standard design temperature of cooling tower system through EnergyPlus simulation. As a result of the simulation, when the condenser water temperature difference from the existing cooling tower design standard is 5K to 7K, the annual cooling energy consumption is reduced by 27,084 kWh, approximately 7.6%. Also, additionally, when the condenser water leaving temperature form the existing cooling tower design standard is 32°C to 23.9°C according to ASHRAE 90.1, the annual cooling energy consumption was reduced by 59.419 kWh, and approximately 16.7%.

구체축열시스템과 외기전담공조시스템이 통합 적용된 오피스건물에서 냉방에너지 소비량 특성

이윤선,이겨레,임재한 한국건축친환경설비학회 2019 한국건축친환경설비학회 논문집 Vol.13 No.2

Thermally activated building system (TABS) has been regarded as one promising technology for energy saving and green-house gas reduction due to the efficiency improvement of a cooling/heating equipment, and feasibility of combining other promising technologies such as ground source heat pumps or cooling towers. TABS can be achieved by running hot/cold water through pipes embedded in a building’s construction. Compared to conventional HVAC systems, TABS delivers higher water temperatures for cooling, and lower water temperatures for heating due to large heat exchange areas. Furthermore, water systems have less transport energy and ductwork spaces compared to existing air systems, due to high thermal capacitance of water. Because of the surface condensation problems in hot and humid weather conditions, TABS needs to be integrated with dehumidification system such as variable air volume (VAV) system or dedicated outdoor air system (DOAS). This study aims to evaluate the cooling energy consumption characteristics of thermally activated building system (TABS) integrated with DOAS in office building compared to the TABS with VAV system. In this study, the design cooling load in office building was firstly evaluated and indoor thermal environment was discussed by considering the surface condensation risk. Finally the cooling energy consumption of TABS with DOAS was compared with TABS and VAV system operation. When the total cooling energy consumption during the cooling period is compared, it is found that the integrated operation of TABS with DOAS is 24% more energy-efficient than integrated operation of TABS with VAV. Night-time electric energy consumption accounts for 34% of the total cooling energy consumption.

가압식 바닥공조 시스템과 야간 외기냉방의 병용에 따른 에너지저감 성능에 관한 연구

윤성훈(Yoon Seong-Hoon) 한국태양에너지학회 2020 한국태양에너지학회 논문집 Vol.40 No.1

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(To) of NPC. As a result, i t 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 To was 16 ~ 20℃. However, when To 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 To was below 20℃ was reduced by 27% compared to that of operating NPC continuously for 8 hours.

사례 분석을 통한 해양심층수의 지역냉방시스템 적용 방안

진수휘(Jin Su-Hwuy),박진영(Park Jin-Young),김삼열(Kim Samuel),김현주(Kim Hyeon-Ju) 한국태양에너지학회 2011 한국태양에너지학회 학술대회논문집 Vol.2011 No.4

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.

스마트온실의 에너지 분석 모델 개발 및 냉방 패키지 성능 분석

구자빈(Goo Ja-Bin),신학종(Shin Hak-jong),곽영훈(Kwak Young-Hoon),허정호(Huh Jung-Ho) 한국태양에너지학회 2021 한국태양에너지학회 논문집 Vol.41 No.6

Through active cooling, smart farms equipped with environmental control systems can overcome the limitations of existing greenhouses that are closed due to heat damage in summer. The control system can extend the crop harvest period by maintaining growth temperature and maintain fixed crop quality throughout the year. Accordingly, there is an increasing need for a cooling performance analysis model for smart farm cooling system applications. Therefore, in this study, a cooling package applicable to greenhouses was proposed, and the energy consumption of the cooling package was analyzed using EnergyPlus. Through consideration and analysis of previous studies, three cooling packages, which included natural ventilation and shading – basic cooling methods – were set up. A greenhouse energy model was developed for a smart farm in Naju. Prior to modeling the cooling packages, the predicted temperature and relative humidity performance of the greenhouse model was verified based on 24-hour measurement data from 9/16 to 9/17 for greenhouses without cooling. The greenhouse model showed performance that satisfied the recommended error value of MBE = -5.8, -6.3% and Cv(RMSE) = 8.7, 8.9% at the dry bulb temperature and relative humidity, respectively. On the basis of the verified model, plant evapotranspiration was simulated using the Stanghellini model, and cooling performance was analyzed using the three cooling package models. Package 1 showed an energy consumption of 20 W/㎡, which is advantageous in terms of energy cost, but cannot maintain an appropriate growth environment. Packages 2 and 3 were found to be disadvantageous in terms of energy cost because of their relatively high energy consumption, but could be advantageous in maintaining growth temperature.

옥상온실과 통합된 소규모 호텔의 냉/난방 부하 산정을 위한 에너지 해석에 관한 연구

최석민,임병주,이유환,도규형 대한설비공학회 2020 설비공학 논문집 Vol.32 No.11

This study conducted a building energy simulation (BES) to compare the heating and cooling loads of a stand- alone greenhouse with a small hotel with an integrated rooftop greenhouse. The TRNSYS program was used to calculate the heating and cooling loads of the buildings. Numerical simulations were conducted for the stand-alone greenhouse model, a stand-alone small hotel model, and a small hotel with an integrated rooftop greenhouse model to compare the heating and cooling loads of each building. The results showed that the heating loads and total loads of the integrated model were reduced 20% and 15.7% than stand-alone model, respectively. Furthermore, if the temperature setting of the greenhouse was changed for different vegetables, the heating and cooling loads of the buildings varied. The setting temperature for high-temperature vegetables showed the largest energy reduction in the heating and cooling loads of the buildings. In conclusion, the integrated rooftop greenhouse had the advantage of energy reduction when it was installed on a conventional small hotel. 본 연구에서는 소규모 호텔 건물과 유리온실이 통합된 건물의 냉난방 부하 산정을 위해 에너지 부하 해석을 수행하였다. 이를 위해 소규모 호텔과 유리온실이 통합된 해석 모델과 분리된 해석 모델을 개발하고 이를 상용 BES 프로그램인 TRNSYS를 이용하여 에너지 부하 해석을 수행하였다. 이에 따른 결론은 다음과 같다. (1) 호텔 건물과 유리온실을 단순 통합시킨 모델의 경우, 난방 에너지 부하량은 약 177 GJ(17.8%) 감소하는 결과를 보였으나 냉방 에너지 부하량은 약 38 GJ(14.5%) 증가하는 경향을 보였다. 이에 따른 전체 에너지 부하량은 약 139 GJ(11%) 감소하는 경향을 보였다. (2) 호텔 건물의 옥상과 유리온실 바닥면의 단열층을 제거하여 에너지 교환을 원활하게 한 경우, 난방 에너지 부하량은 약 200 GJ(20.1%) 감소하는 결과를 보였으며, 냉방 에너지는 29 GJ(9.9%) 증가하는 경향을 보였다. 이에 따른 전체 에너지 부하량은 171 GJ(15.7%) 감소하는 경향을 보였다. 즉, 단열층을 제거하는 경우 유리온실의 에너지 절감량이 더 효과적인 것을 확인하였다. (3) 유리온실 내부의 생육 작물에 따라 기준 온도가 변할 시의 에너지 부하량 변화를 추가적으로 확인하였다. 기준 온도가 변함에 따라 에너지 부하의 절감량은 120~220 GJ까지 변하는 것을 확인하였으며, 에너지 절감률도 10.6%~18.7%까지 변하는 것을 확인하였다. 이를 통해 고온성 작물을 유리온실에서 재배하는 경우 에너지 절감량과 절감률이 크게 나타나는 것을 확인하였다. 위와 같이 소규모 호텔 건물위에 유리온실을 설치하여 에너지 교환이 원활이 이뤄지도록 설계하는 경우 에너지 부하량의 절감하는 효과가 있는 것을 확인하였다. 또한 본 시뮬레이션 결과를 바탕으로 생육 작물에 따른 옥상 유리온실의 냉난방에 필요한 에너지 산정 및 설비 시스템 설계에 활용 될 수 있을 것으로 판단된다. 다만 현 시스템을 국내 실정에 맞게 적용하기 위해서는 실증 실험 및 적용 타당성을 검증하는 추가 연구가 수행되어야 할 것으로 판단된다.

패시브 공동주택 세대 위치별 에너지요구량에 따른 냉난방 에너지비용 비교 연구

이명주(Lee, Myoung-Ju),임인혁(Lim, In-Hyok),허다운(Hur, Da-Woon) 대한건축학회 2015 대한건축학회논문집 Vol.31 No.11

We analyzed and compared the cooling/heating energy demand and cost of nine households of different positions in a passive house Apartment. To do this, the Passive House Planning Package(PHPP) was used on Building 102 of the Net Zero Energy Housing Complex located in Hagye-dong, Nowon-gu, Seoul, Korea. For the heating energy demand, it was analyzed that the middle floor and the first floor have the lowest and highest demands, respectively, and the highest demand was about twice as the lowest. On the same floor, the units in the middle had the lowest demand, while the units on the right and left of the building had little difference. For the cooling energy demand, the higher floors had higher demand, and the highest cooling energy demand was about 40% higher than the lowest. There was not much difference between the units on the same floor when it comes to cooling energy. By analyzing the cooling and heating costs of each household, we concluded that the household with the highest electricity bills payed about 50% higher cost than the one with the lowest bills.

공동주택에서 바닥복사냉방의 적정 운영방안에 관한 연구

조영흠,석호태,여명석,김광우 대한설비공학회 2004 설비공학 논문집 Vol.16 No.6

In this study, the operation strategy of the radiant floor cooling is evaluated in terms of indoor environmental conditions and energy consumption through simulations using the TRNSYS comparing the existing cooling operation. The operation strategy during continuously operated for cooling is proposed that a representative room had additional equipments and other rooms were operated with only a radiant floor cooling system and that system and control method for cooling are varied with period while intermittently operated for cooling. Specifically, when there are no people in the room, rooms were operated by only radiant floor cooling system using cooling storage and when people are occupied, rooms were operated by dehumidification and supplementary cooling device with radiant floor cooling system. The results of this study show that proposed operation strategy can stably maintain the set room air temperature and can reduce the energy consumption compared to the existing cooling method during continuously operated for cooling. While intermittently operated for cooling, the difference of set room air temperature by proposed operation strategy does not happen, satisfying comfort standards and the radiant floor cooling can expect to supply stable electric power because of decreasing demand for peak electric power of energy consumption.