• 교육녹색환경연구
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• 제11권2호
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• pp.19-27
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• 2012

This study was carried out in order to establish the estimation equation for school power consumption using regression analysis based on collected power consumption for two years of weather data and schools are located in Central Changwon and Masan district in Changwon city. (1) The power consumption estimation equation for Heating and cooling is calculated using power consumption per unit volume, the difference between actual power consumption and results of estimation equations is 4.1%. (2) The power consumption estimation equation for heating load is showed 2.6% difference compared to actual power consumption in Central Changwon and is expressed 2.9% difference compared to that in Masan district. Therefore, the power consumption prediction for each school using the power consumption estimation equation is possible. (3) The power consumption estimation equation for cooling load is showed 8.0% difference compared to actual power consumption in Central Changwon and is expressed 2.9% compared to that in Masan district. As the power consumption estimation equation for cooling load is expressed difference compared to heating load, it needs to investigate influence for cooling load.

• 한국건축시공학회지
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• 제18권5호
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• pp.463-469
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• 2018

기존의 다층으로 구성되어 시공성이 낮은 옥상녹화 공법의 개선을 위해 개발한 방수 방근 시트 일체화 옥상녹화박스 유닛공법의 일체화를 위해 사용하는 전자기 유도가열방식의 금속 고정구와 콘 형상 고정구의 부착성능을 평가하기 위해 엔지니어링 PE, TPO, PVC 시트 등 3종류의 시트에 가열온도에 따른 부착성능 및 동일한 시험체로 냉열반복 후 부착성능을 측정하였다, 그 결과는 엔지니어링 PE시트에 부착한 고정구의 부착성능이 가장 우수하게 나타났으며, 금속고정구는 가열온도가 올라갈수록, 콘 형상 고정구는 가열온도가 낮을수록 우수한 부착성능을 보여주었고, 냉열 반복 후 부착시험 결과는 상온 부착시험 결과와 동일하게 나타났다. 기존의 양면 부틸테이프 고정방식의 콘 형상 고정구는 낮은 부착하중과 냉열반복에 의한 뚜렷한 성능저하가 발생하는데 비하여 전자기 유도가열방식의 고정구는 우수한 성능을 유지하였다.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.825-832
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• 2008

A simulation program is developed for analysing thermal networking process between the District heating and the CES(Community Energy Supply) systems. The effects of thermal networking on the District heating facilities previously being operated are implemented using mathematical correlations in terms of the fuel consumption and energy load such as heating and electricity. The operational characteristics according to the prime movers is modeled based on the materials of efficiency as a function of operational load. The unit energy load model is also developed extensively for several building types such as apartment complex, hotel, hospital, buildings for business and commercial use respectively. The specific features of the newly developed program in simulation of thermal networking process in district heating is described in terms of the reliability and the easiness for operating it etc.

• 설비공학논문집
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• 제20권4호
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• pp.245-251
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• 2008

The cooling load in winter is significant in buildings and hotels because of the usage of office equipments and the high efficiency of wall insulation. Hence, the development of a multi-heat pump that can cover heating and cooling simultaneously for each indoor unit is required. In this study, the operating characteristics and performance of a simultaneous heating and cooling heat pump in the heating-main operating mode were investigated experimentally. The system adopted a variable speed compressor with four indoor units and one outdoor unit with R-410A. In the heating-main mode, the cooling capacity was lower than the design cooling capacity due to the reduction of the flow rate in the indoor unit for the cooling, with the increase of the heating capacity. To solve these problems, the performance characteristics of the simultaneous heating and cooling heat pump in the heating-main mode were investigated by varying the flow rate to the indoor unit for the cooling and the compressor rotating speed. In addition, the adequate control methods were suggested to improve the system efficiency.

• 설비공학논문집
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• 제26권12호
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• pp.572-578
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• 2014

Heating energy was measured in an apartment housing unit with a district heating system, varying the kind of hot water distributors. Ondol coils passing through a living room raised the temperature of the room where the heating was turned off. Including this characteristic of Ondol heating into the modeling, we performed simulations and showed a verification by comparison with the results of measurements. As a result, a main flow control method, which changes hot water flow rate supplied to a housing unit according to the thermal load, can reduce the supplied flow rate and lower the return temperature, compared with a constant flow method. That can result in decreased heat loss in utility-pipe conduits even though the heating energy supplied is almost the same. An outdoor reset control that raises the temperature of the supplied hot water if the outdoor temperature falls has the effect of a quicker response in heating than the reduced flow rate and return temperature.

• 한국산학기술학회논문지
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• 제14권9호
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• pp.4197-4203
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• 2013

본 실험연구는 인버터 압축기를 적용한 실내기 3실을 가진 멀티형 열펌프 시스템의 난방운전 시 열펌프의 난방성능을 연구하였다. 멀티형 열펌프의 운전특성은 항온항습 기능을 가진 공기엔탈피방식의 멀티형 칼로리미터를 이용하여 측정되었다. 난방표준 및 난방저온 온도조건에서 실내기 운전조합에 따른 실험을 수행하여 난방성능 변화를 관찰하였다. 실내기 3실을 가진 열펌프의 실내기 운전조합에 따른 난방표준 및 난방저온 운전에서 난방능력, 난방 COP, P-h선도로부터, 3실을 가진 열펌프의 운전특성과 냉매 사이클의 거동을 조사하였다. 열펌프의 운전부하와 성능은 실내기 조합에 의한 부분부하에 의존하므로 열펌프의 난방능력과 사이클의 거동은 다르게 관찰되었다. 표준온도 시험조건 대비 저온 시험조건의 난방능력과 난방 COP는 감소하였다. 또한 실내기 조합에 대한 냉매사이클은 P-h 선도를 사용하여 분석되었다.

• 설비공학논문집
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• 제20권11호
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• pp.718-726
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• 2008

The cooling load in winter is significant in buildings and hotels because of the usage of office equipments and the high efficiency of wall insulation. Hence, the development of a multi-heat pump that can cover heating and cooling simultaneously for each indoor unit is required. In this study, the performance of a simultaneous heating and cooling heat pump was investigated in the heat recovery mode (HR mode). The system adopted a variable speed compressor using R410A with four indoor units and one outdoor unit. In the HR mode, the capacity and COP were improved as compared with those in the cooling or heating mode because the waste heat in the outdoor unit was utilized as useful heat in the indoor units. However, energy imbalance between heating and cooling capacity of each indoor unit was observed in the 2H-1C HR mode. Therefore, the performance of the system in the 2H-1C HR mode was enhanced by controlling refrigerant flow rate through the outdoor unit.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 추계학술발표대회 논문집
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• pp.147-154
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• 2008

A simulation program is developed for the optimal design of small scale district heating and cooling system. Main features for the simulation program are the reliability and the easiness for the optimal design of the DHC(District Heating and Cooling) systems. In order for implementing those features, the operational characteristics according to the prime movers is modeled based on the materials of efficiency as a function of operational load. The unit energy load model is also developed extensively for several building types, of which the corresponding district consist, such as apartment complex, hotel, hospital, buildings for business and commercial use respectively. The specific features and the overall procedure of the simulation are described in brief in this paper. The results of the simulation for several test cases will be presented in subsequent study.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2002년도 학술대회논문집
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• pp.293-296
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• 2002

This paper describes the instantaneous current resultant type load parallel high frequency resonant inverter consisting of three unit half-bridge serial and parallel resonant inverter can be used as power source of induction heating. This proposed inverter can reduce distribution of the switching current because of using the current of serial resonant circuit to the input current of the parallel one. The analysis of the proposed circuit is generally described by using the normalized parameters. Also, the principle of basic operating and the its characteristics are estimated by the parameters such as switching frequency($\mu$), load resistance(λ). Experimental results are presented to verify theoretical discussion. This proposed inverter will can be practically used as a power supply in various fields as induction heating application, DC-DC converter etc.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 추계학술발표대회 논문집
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• pp.263-268
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• 2008

In a residential complex case, the efficiency of land use are maximized, but a variation of external condition such as load in-equality, the increase in wind velocity and solar radiation by a height causes increasing energy in a building. Besides, because of increasing window size for a lighting and a view, it comes heating load in winter and cooling load in summer. A choice of cooling-system is important for this reason. Recently an internal high-rise residential complex installs an air-cooling system and operates individual heating. However, this study applies water-cooling used one public cooling-tower instead of an air-cooling system, also with an efficiency test of an air and a water-cooling system, consider an internal applicability.