• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.1136-1145
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• 1996

This study was to develop the most effective cooling system which is needed to cool greenhouse during summer night to get early blooming of strawberries. Various cooling systems were designed and constructed to utilize the cool air and water from tan abandoned coal mine. Cooling systems built for this study were an evaporative cooling system with pad, cooling system using a small or large radiator , and duct cooling system using cool are drawn from coal mine. These systems were individual tested to investigate their effects on cooling greenhouse during summer night. Also, a combined cooling system was tested with operating an evaporative cooling system, small radiator, and duct cooling system simultaneously. The results in this study showed that individual cooling systems such as evaporative cooling system, small radiator, and cooling duct had about the same effect on cooling greenhouse. The combined system had little better cooling effect than that of individual cooling syst m except the large radiator . The most effective system for cooling of greenhouse was obtained with using a large a large radiator as the heat exchanger. With operating a large radiator, temperature inside the greenhouse was dropped to about 15-16$^{\circ}C$ while outside temperature was 23-24$^{\circ}C$ during summer night.

• 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.

• 생물환경조절학회지
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• 제2권2호
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• pp.99-109
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• 1993

Cooling of nutrient solution is essential to improve the growth environment of crops in hydroponic culture during summer season in Korea. This study was carried out to provide fundamental data for development of the cooling system satisfying the required cooling load of nutrient solution in hydroponic greenhouse. A numerical model for prediction of the cooling load of nutrient solution in hydroponic greenhouse was developed, and the results by the model showed good agreements with those by experiments. Main factors effecting on cooling load were solar radiation and air temperature in weather data, and conductivity of planting board and area ratio of bed to floor in greenhouse parameters. Using the model developed, the design cooling load of nutrient solution in hydroponic greenhouse of 1,000$m^2$(300pyong) was predicted to be 95,000 kJ/hr in Suwon and the vicinity.

• 한국농공학회지
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• 제41권1호
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• pp.60-71
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• 1999

This study was performed to improve underirable warm greenhouse environment by fog cooling system in summer season. The resultsof droplet size analysis and cooling effects for fog cooling system are summarized as follows ; 1. At the pump pressure of 70kgf/$\textrm{cm}^2$ , the mean (SMD) drop size was 22.6${\mu}{\textrm}{m}$ and the maximum and minimum drop size was 45.68${\mu}{\textrm}{m}$ and 1.73${\mu}{\textrm}{m}$ , respectively, and almost all of the drop size was less than 40${\mu}{\textrm}{m}$. 2. The temperature of fog cooling greenhouse with 60% shading was dropped more than 2$^{\circ}C$ below the ambient temperature , while the greenhouse temperature without shading was 1$^{\circ}C$ higher than the ambient temperature. 3. It was found that fog spraying intervals were significantly influential on cooling effect. 4. When the greenhouse was ventilated sufficiently by natural vent system, green house temperature could be maintained by 2.5$^{\circ}C$ lower than the ambient temperature, while it was difficult to drop the greenhouse temperature below ambient temeperature without sufficient ventilation. 5. It was found that the temperature of experimental greenhouse could be maintained 3$^{\circ}C$ to 14$^{\circ}C$ lower that of control greenhouse though there were variations depending on experimental and weather conditions.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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• pp.399-404
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• 1999

This study were performed to find the cooling effect and to provide design data during summer season for the Pad& Fan system of greenhouse . The temperature variation along the greenhouse width were analyzed. Also, the effect of the pad location and fan capacity on the cooling of the greenhouse were analyzed. While Pad &Fan systems were operating the temperatures in greenhouse were very different along the meausring locations. It is recommeded that PAD location and FAN capacity should be considered to design the Fan and Pad system in order to provide greenhouse the optimum temperature condition.

• 생물환경조절학회지
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• 제29권3호
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• pp.265-276
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• 2020

본 연구는 여름철 고온기에 작물을 정상적으로 재배할 수 있는 환경을 조성하여 농산 가격이 가장 높은 여름철에 수확량을 높이고 재배기간을 연장시켜 농가소득을 올릴 수 있는 방안을 제시하고자 수행하였다. 바닥면적 504㎡의 연동온실의 최대 냉방부하는 462,609W로 나타났으며, 고온기에 온실을 차광하지 않고도 32℃ 이하로 유지하기 위해서는 시간당 472L의 물을 포그 분무해야 하는 것으로 나타났다. 포그 냉방 시스템은 포그 장치, 유동팬, 차광장치로 구성하고, 이들 장치를 효과적으로 제어할 수 있는 포그 냉방 자동제어장치를 개발하였다. 포그 냉방시스템의 냉방 성능은 온실 외기온 보다 내부온도를 6℃ 낮출 수 있는 것으로 나타났다. 포그 온실의 내부 상대습도는 주간에는 40~80%로 대조 온실의 20~60% 보다 약 20% 높게 나타나 오이의 생육에 기여하는 것으로 나타났다. 오이의 생육상태는 포그 온실에서 재배한 오이가 대조 온실에 비해 초장, 엽장, 엽폭, 엽수, 엽록소 값이 전체적으로 높게 나타났다. 포그 온실의 오이 수확량은 대조 온실에 비해 단동 온실에서는 1.8배, 연동 온실에서는 2배 높게 나타났다.

• 한국농공학회지
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• 제43권6호
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• pp.120-126
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• 2001

This experiment was carried out to analyse on the cooling and dehumidifying effects of greenhouse by air-to-water heat pump system employing the air as cooling source. following results were obtained ; 1. The coefficients of performance (COP) of heat pump itself and total heat pump system were approximately 2.71~2.88 and 1.99~2.22, respectively. 2. The night-time cooling load of experimental greenhouse was 64.9 MJ/h, and the heat absorbed (cooling load) from heat pump system was 816.3~1,004.6 MJ/day. 3. The dehumidified moisture amount from experimental greenhouse was 7.0~15.0 kg/h. 4. The night time temperature of experimental greenhouse cooled by heat pump system could be maintained 4~6$^{\circ}C$ lower than that of control greenhouse which was almost equal to outside air temperature.

• 생물환경조절학회지
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• 제10권1호
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• pp.10-14
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• 2001

포그냉방시스템의 냉방효과는 온실 내부의 상대습도, 공기유동과 밀접한 관계가 있다. 냉방설계용 VETH선도에서 냉발효율은 환기회수의 증가와 그에 상응하는 분무수량의 증가로 인하여 개선될 수 있다. 시간제어방식을 이용한 무차광 실험온실에서 분당 환기회수가 평균 0.77회, 분무수량이 2,009g 일 때 온실 내부의 기온이 31$^{\circ}C$로 외부기온과 거의 같게 나타났으며, 이 때의 증발효율은 82%이다. 분당 환기회수가 평균 0.26회, 분무수량이 1.256g인 경우 무냉방 온실의 기온과 비슷한 37.1$^{\circ}C$였다. 차광율 70%인 실험온실의 분당 환기환수가 평균 2.59회, 분무수량이 2,009g 일 때, 내부의 상대습도는 증가하나 기온은 하강하지 못했다. 그러나 분당 환기회수가 평균 2.33회, 분무수량이 2,009g인 경우 내부의 기온이 31.4$^{\circ}C$로 이 때 온실의 유입구 풍속은 최고 1.9m.s$^{-1}$였다. 시간제어의 경우 일정간격으로 일정한 수량을 분무하기 때문에 분무입자가 모두 증발하지 못하고 온실 내부에 누적되어 온실 내부의 상대습도를 증가시켜 냉방효율을 감소 시키는 원인이 되고 차광망이 온실내부의 공기흐름을 차단하여 증발효율을 감소시키는 것으로 나타났다. 포그냉방시스템의 냉방효율을 높이기 위해서는 온실 내부의 상대습도에 의한 제어방식과 내부 공기의 순환에 대한 연구가 필요하다.

• 생물환경조절학회지
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• 제24권3호
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• pp.147-152
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• 2015

온실의 냉방부하 산정방법 개발을 위하여 열수지 방법에 기초한 냉방부하 산정식을 구성하고, 포그냉방 온실에서 냉방부하를 실측하여 검증하였다. 포그냉방 온실의 냉각열량은 포그분사에 의한 증발수량에 물의 증발잠열을 곱하여 구할 수 있다. 여기서, 증발수량은 포그 분사량에 증발효율을 곱하면 구할 수 있으며, 즉 분무수량을 계측하고 포그시스템의 증발효율을 알면 온실의 냉방부하를 실측할 수 있다. 따라서 온실의 냉방부하 실측을 위하여 실험온실에서 포그시스템의 증발효율을 실험하고, 실험온실의 열환경 계측과 더불어 포그 분사량을 계측하여 냉방부하 산정방법을 검토하였다. 먼저 냉방부하 산정식의 환기전열량을 검토하기 위하여 냉방을 실시하지 않은 상태에서 환기량 실측 실험을 통해 비교한 결과 열수지식을 이용한 환기전열량 예측은 비교적 양호한 결과를 보이는 것으로 나타났다. 이류체 포그시스템의 증발효율은 0.3~0.94의 범위를 보였으며 평균 0.67로 나타났고, 환기율이 증가함에 따라 커지는 것으로 나타났다. 포그냉방을 실시하면서 온실의 환경을 계측하여 열수지식으로 냉방부하를 계산하고, 분무량 실측치로부터 증발 냉각열량을 구하여 비교한 결과 냉방부하 계산치와 실측치는 대체로 유사한 경향을 보이는 것으로 나타났다. 냉방부하가 낮은 경우에는 실측치에 비하여 약간 크게 예측되었고, 냉방부하가 높은 경우에는 실측치보다 작게 예측되었다. 온실의 냉방시스템 설계 시에는 최대냉방부하를 이용하여 냉방설비의 용량을 결정하게 된다. 따라서 냉방부하가 큰 쪽에서 실측치보다 작게 예측되는 부분은 검토가 필요하지만 설비용량 산정시의 안전계수를 고려하면 본 연구에서 제시한 냉방부하 산정방법은 온실의 환경설계에 적용할 수 있는 것으로 판단된다.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2000년도 학술발표회 발표논문집
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• pp.308-314
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• 2000

Objects of this study were to find the cooling effect of solar-heated greenhouse with rock bed storage in summer season and to suggest operation method of cooling energy saving in summer cropping greenhouse. Experiments were performed to analyze inside environment variation of solar-heated greenhouse. When we took account of different shading and ground conditions of greenhouse, we could conclude that inside average daytime temperature of the solar-heated greenhouse was 2.0∼2.4$^{\circ}C$ lower than the general greenhouse in summer season.