• 생물환경조절학회지
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• 제26권4호
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• pp.258-267
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• 2017

The price competitiveness of photovoltaic system (PV system) has risen recently due to the growth of industries, however, it is rarely applied to the greenhouse compared to other renewable energy. In order to evaluate the application of PV system in the greenhouse, power generation and optimal installation area of PV panels should be analyzed. For this purpose, the prediction of the heating and cooling loads of the greenhouse is necessary at first. Therefore, periodic and maximum energy loads of a multi-span greenhouse were estimated using Building Energy Simulation(BES) and optimal installation area of PV panels was derived in this study. 5 parameter equivalent circuit model was applied to analyzed power generation of PV system under different installation angle and the optimal installation condition of the PV system was derived. As a result of the energy simulation, the average cooling load and heating load of the greenhouse were 627,516MJ and 1,652,050MJ respectively when the ventilation rate was $60AE{\cdot}hr^{-1}$. The highest electric power production of the PV system was generated when the installation angle was set to $30^{\circ}$. Also, adjustable PV system produced about 6% more electric power than the fixed PV system. Optimal installation area of the PV panels was derived with consideration of the estimated energy loads. As a result, optimal installation area of PV panels for fixed PV system and adjustable PV system were $521m^2$ and $494m^2$ respectively.

• 한국기후변화학회지
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• 제8권4호
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• pp.377-384
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• 2017

Amid growing concerns about energy security, energy prices, economic competitiveness, and climate change, district heating (DH) system has been recognized for its significant benefits and the part it can play in efficiently meeting society's growing energy demands while reducing environmental impacts. Policy makers often need to quantify the fuel and carbon dioxide ($CO_2$) emissions savings of DH system compared to conventional individual heating (IH) system in order to estimate its actual emissions reductions. The objective of this paper is to calculate energy efficiency and $CO_2$ emissions saving, and to propose the future direction for DH system in Korea. DH system achieved total system efficiencies of 67.9% compared to 54.1% for IH system in 2015. DH system reduced $CO_2$ emissions by $381,311ton-CO_2$ (4.1%) compared to IH system. The results suggest that DH system is more preferred than IH system using natural gas. In Korea, the aim is to reduce dependence on fossil fuels and to use energy more efficiently. DH system have significant potential with regard to achieving this aim, because DH system are already integrated with power generation in the electricity since combined heating and power (CHP) are used for heat supply. Although the future conditions for DH may look promising, the current DH system in Korea must be enhanced in order to handle future competition. Thus, the next DH system must be integrated with multiple renewable energy and waste heat energy sources.

• 태양에너지
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• 제19권1호
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• pp.59-65
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• 1999

The zone of greenhouse in Korea increase on a scale yearly. Particularly, greenhouse take up a important value on the agriculture economy. Greenhouse of scale, material, heating system, and drain is progressing to industrialization. The dry bulb temperature, humidity, photosynthesis and so forth are necessary to maintain environment control of greenhouse. The dry bulb temperature among them greatly affects growing of a plant. The purpose of this study is to analyzed the indoor environment control system and the characteristic of dry bulb temperature distribution on a large scale greenhouse in summer season.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.305-310
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• 2012

In 2009, The Ministry of Land, Transport and Maritime Affairs, Korea opens apartment maintenance fee to public in "Apartment Management Info System". The high energy consumption component of apartment, which is hot water, water, electricity and heating, is released to public on this system. Through this system, apartment energy consumption and greenhouse gas emissions data can be compiled and expected to be accurately analyzed. Energy consumption and greenhouse gas emissions statistics of the apartment are collected being made to reduce energy and gas emissions. However, The accurate survey of energy consumption trends have not been accomplished. The energy consumption and greenhouse gas emissions survey in Apartment should be made first in order to reduce energy consumption. and then the correlation factors analysis which is affecting energy consumption is required. The purpose of this study is to analyze energy consumption characteristics of apartment in Bundann-gu, Seongnam, Korea in monthly, unit area and building built year basis. And then the research can be used as the basis of policy to Reduce energy consumption and greenhouse gas emissions.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 추계학술발표대회 논문집
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• pp.199-204
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• 2009

This study analyzed the central heating system and the cogeneration system among the methods of supplying energy which have application to the Hydrogen Fuel Cell system and apartment complexes for performance evaluations. Therefore, a feasibility study on the first application of this system in an apartment complexes was considered to evaluate the energy performance by the amount of fuel consumed by the system using Hydrogen Fuel Cell energy and environmental performance by the amount of greenhouse gas emissions. As a result, the Hydrogen Fuel Cell system consumes 83% of fuel while the cogeneration system consumes 81% of fuel comparison to conventional central heating system. The Hydrogen Fuel Cell and the cogeneration system produce 73%t and 70% of greenhouse gas emissions in comparison to conventional central heating system.

• Journal of Advanced Marine Engineering and Technology
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• 제41권1호
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• pp.99-104
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• 2017

본 연구는 태양일사에 의하여 가열되는 온실상단에 고온의 태양잉여열을 축열조에 축열한 후 이를 이용하여 온실을 난방하는 히트펌프시스템의 실증연구에 관한 것으로 히트펌프시스템은 축열조를 구비하고, 각종 열교환을 위한 판형열교환기, 팬코일유닛 그리고 부가적인 에너지원으로 태양일사를 직접 집열할 수 있는 태양집열기로 구성되어 있다. 히트펌프시스템은 R410a냉매를 사용하며 일반적인 히트펌프시스템과 마찬가지로 외기열원만으로도 운전될 수 있으며, 온실내부의 설정온도에 따른 제어로직에 따라 외부조작없이 온실상단열의 축열운전, 외기공기에 의한 외기열원 및 축열조의 온수를 히트펌프의 작동 없이 난방하는 다수의 운전방식이 자동적으로 운전되도록 하였다. 개발된 축열식 히트펌프의 현장평가 성능실험을 위하여 제주시 조천리에 있는 $100m^2$ 크기의 온실에 설치하고 10월부터 12월까지 운전하였다. 실증연구 실험을 수행한 결과로써 외기열원을 이용하여 난방 할 경우 난방열량은 19.9 kW의 용량을 얻을 수 있었으며, 온실상단의 잉여열에 의하여 축열조의 온수로 히트펌프운전 없이 직접 난방 할 경우에 난방열량은 21.4 kW로 외기난방과 비슷한 난방용량을 나타내는 것을 알 수 있었다.

• 한국전자통신학회논문지
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• 제10권5호
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• pp.623-628
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• 2015

현재의 시설하우스에서의 난방 방식은 한 곳에 고정되어져서 위치에 따른 온도 편차가 심해 질 수밖에 없는 실정이다. 채소나 과일 작물 등을 재배하는 시설하우스는 적정 온도의 유지가 필수적인데 하우스 내부의 상하 온도 차이로 인해 적정 난방 또는 냉방을 위한 에너지 소모가 많다. 본 논문에서는 하우스 내부의 공기 순환을 효율적으로 할 수 있는 새로운 형태의 난방 방식인 수직형 교반 히터 자동 제어 시스템을 제안한다. 시설하우스 상 하부의 온도를 이용하여 수직형 교반 히터의 공기 순환 팬과 히팅을 상황에 맞게 독립적으로 제어함으로써 최소한의 전기 소비로 난방의 효율을 극대화 시켜 계획 가능한 작물 생산과 난방비 절감이 가능하다.

• 한국태양에너지학회 논문집
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• 제21권2호
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• pp.27-34
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• 2001

The greenhouse heating system using solar energy has been realized in the protective agriculture in this study in order to analyse the thermal energy characteristics of the system the effects of ambient air temperature, solar radiation, relative humidities and water content of ambient air on the greenhouse air temperature were investigated through computer simulation experimental analysis for validation of the simulation. The results from this study are summarized as follows: 1) The expected values of inside air temperature for the system solar energy were very much close to the experimental values. 2) In the system using solar energy, the expected values of daytime surface temperature of soil by computer simulation were very much similar to the measured values, but those of nighttime were higher than the measured value by almost $2.5^{\circ}C$. 3) Heat loss of daytime was found to be larger than that of night time as much as 2.0 to 4.2 times for the system using solar energy. 4) In the system using solar energy. while the ambient air temperature varied between $-7^{\circ}C$ and $-3.8^{\circ}C$, the temperature of the inside air was maintained between $0^{\circ}C$ and $22^{\circ}C$. 5) At the minimum ambient temperature of $-7^{\circ}C$, the temperature of the inside air was $0^{\circ}C$.

• 한국농공학회논문집
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• 제59권6호
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• pp.1-8
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• 2017

The purpose of this study was to provide basic data for development of environmental design technology for greenhouses constructed in reclaimed lands. We analyzed the climatic conditions around seven major reclaimed land areas in Korea, which have a plan to install advanced horticultural complexes. The characteristics of heating load through the thermal environment measurement of the greenhouse in Saemangeum were analyzed. The part to be applied to the environmental design of the greenhouses in reclaimed lands were reviewed. The overall heat transfer coefficient of the experimental greenhouse with the aluminum screen and multi-layer thermal curtain averaged $3.79W/m^2^{\circ}C$. It represents a 44 % heat savings rate compared with plastic greenhouses with a single covering, which was significantly lower than that of the common greenhouses with 2-layer thermal curtains. This is because the experimental greenhouse was installed on reclaimed land and wind was stronger than the inland area. Among the total heating load, the transmission heat loss accounted for 96.4~99.9 %, and the infiltration loss and the ground heat exchange were low. Therefore, it is necessary to take countermeasures to minimize the transmission heat loss for greenhouses constructed in reclaimed lands. As the reclaimed land is located on the seaside, the wind is stronger than the inland area, and the fog is frequent. Especially, Saemangeum area has 2.6 times stronger wind speed and 3.4 times longer fog duration than the inland area. In designing the heating systems for greenhouses in reclaimed lands, it is considered that the maximum heating load should be calculated by applying the wind coefficient larger than the inland area. It is reasonable to estimate the operation cost of the heating system by applying the adjustment factor 10 % larger than the average in calculating the seasonal heating load.

• 생물환경조절학회지
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• 제22권4호
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• pp.328-334
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• 2013

본 연구에서는 온실 내부의 태양 잉여열과 외부의 공기열을 선택적으로 열원으로 이용함으로써 히트펌프의 성능을 향상시키고, 온실의 환기 지연을 통해 이산화탄소 시용비용을 절감할 수 있는 온실 공조시스템을 개발하고자 하였다. 본 시스템의 축열 과정은 태양 잉여열을 이용하는 내부순환모드와 외기열을 이용하는 외부순환모드가 온실 내부온도에 따라 자동으로 절환되도록 구성하였으며, 히트펌프 가동, 축열모드 절환, 난방 가동을 위한 6개의 온도값을 입력함으로써 축열과 난방이 자동으로 수행되도록 설계하였다. 단동온실을 대상으로 무환기 조건에서 기초시험을 수행한 결과, 태양 잉여열을 이용한 축열은 약 11시부터 시작되어 평균 3시간 30분 정도 유지되었으며, 주간의 온실 내부온도는 환기를 수행하지 않음에도 대부분 약 $20{\sim}28^{\circ}C$ 범위를 유지하였다. 주간 내부순환모드에서 시스템의 난방성능계수는 약 3.35로 야간 외부순환모드의 2.46 및 주간 외부순환모드의 2.67에 비해 각각 36% 및 25% 향상됨을 확인하였다. 본 시스템의 개선사항으로 태양 잉여열의 효율적 이용을 위해 축열조 관리온도를 상승시킬 수 있는 고효율 히트펌프의 적용이 필요하며, 온실의 무환기 운용에 따른 과습환경의 조성을 방지하고 태양 잉여열 수준이 높은 시기에 온실의 온도상승을 방지하기 위해 강제환기를 운전모드에 추가할 필요가 있는 것으로 판단되었다.