• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.420-428
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• 2019

This study is the heating energy saving test of the high-bed strawberry crown heating system. The system consists of electric hot water boiler, thermal storage tank, circulation pump, crown heating pipe(white low density polyethylene, diameter 16mm) and a temperature control panel. For crown heating, the hot water pipe was installed as close as possible to the crown part after planting the seedlings and the pipe position was fixed with a horticultural fixing pin. In the local heating type, hot water at $20{\sim}23^{\circ}C$ is stored in the themal tank by using an electric hot water boiler, and crown spot is partially heated at the setting temperature of $13{\sim}15^{\circ}C$ by turning on/off the circulation pump using a temperature sensor for controlling the hot water circulation pump which was installed at the very close to crown of strawberry. The treatment of test zone consisted of space heating $4^{\circ}C$ + crown heating(treatment 1), space heating $8^{\circ}C$(control), space heating $6^{\circ}C$ + crown heating(treatment 2). And strawberries were planted in the number of 980 for each treatment. The heating energy consumption was compared between November 8, 2017 and March 30, 2018. Accumulated power consumption is converted to integrated kerosene consumption. The converted kerosene consumption is 1,320L(100%) for space $8^{\circ}C$ heating, 928L(70.3%) for space $4^{\circ}C$ + crown heating, 1,161L($88^{\circ}C$) for space $6^{\circ}C$ + crown heating). It was analyzed that space $4^{\circ}C$ + pipe heating and space $6^{\circ}C$ + crown heating save heating energy of 29.7% and 12% respectively compared to $8^{\circ}C$ space heating(control).

• Journal of Bio-Environment Control
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• v.20 no.2
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• pp.72-77
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• 2011

The objective of the present study is to provide the basic data necessary for estimating the overall heat transfer coefficient of commercial plastic greenhouse. The heat flow through covering of greenhouses was measured and the variation of overall heat transfer coefficient was analyzed. Because the inside-outside temperature difference of greenhouse to indicate the stabilized overall heat transfer coefficient was different depending on the number of covering layers, the actual overall heat transfer coefficient should be decided in range of inside-outside temperature difference to make the coefficient constant for each covering method. The variation trend of the overall heat transfer coefficient according to the inside-outside temperature difference corresponded with the existing research results, but the specific values of temperature difference to present the stabilized overall heat transfer coefficient were different each other. The increase rates of overall heat transfer coefficient with wind speed were quite dissimilar among several research results and the quantity of heat loss through covering according to the wind speed in the double layers covered or curtained greenhouse was less than that in the single layer covered greenhouse. Because there was large variations among the values of overall heat transfer coefficient for the polyethylene film greenhouses, it was required to establish the standardized environmental condition for experiment measuring heat flow through covering in commercial greenhouse.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1999.07a
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• pp.320-325
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• 1999

세계기후협약으로 인하여 우리나라는 화석연료 사용량을 최소한 2010년까지 2000년 수준으로 감축시켜야할 처지에 놓여 있다. 따라서 지구 온난화의 주 요인이 되고 있는 이산화탄소 배출량을 2010년 예상배출량의 21%정도를 감축해야 하며, 경제활동은 1/4이상이 축소되는 영향을 받게 된다(차재호, 1998). 따라서 현재의 화석에너지에 의존하는 난방법은 자연에너지 또는 전기에너지 등으로 대부분이 전환되어야 할 것으로 전망하고 있다 그러나 농업에 이용되고 있는 난방에너지는 화석에너지에 집중되어 있으며, 온실, 축사, 버섯재배사 등에서 겨울철 난방에 소요되는 에너지 비용은 총경영비의 10-40%를 차지하고 있다. (중략)

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1151-1158
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• 2017

The Effluent Heat Pipe integral with the heater is a device that recreates unused thermal energy from the plant in winter, and thus reuses unused energy before releasing the exhaust heat. Through the establishment of facility horticulture and glass greenhouses, we identified the problems of our agricultural heaters, and we proposed efficient agricultural efficiency and smart control systems for optimum agricultural efficiency and smart house.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2003.04a
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• pp.44-47
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• 2003

시설재배에서 가장 시급한 과제를 꼽는다면 난방에너지 비용의 절감 대책을 들 수 있다. 시설원예농가의 경영비의 30% 이상을 차지하는 난방에너지 비용이야말로 시설원예농가의 경쟁력을 떨어뜨리고, 시설농업의 발전을 가로막는 주원인이라고 할 수 있다. 더욱이 최근의 이라크 전쟁과 화석연료자원의 고갈 예고 등 세계적인 경향 또한 우리나라 시설원예 산업의 발전에 부정적인 영향을 미치고 있는 실정이다. (중략)

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2000.10b
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• pp.124-127
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• 2000

시설원예의 궁극적인 목적은 인위적인 환경조절을 통해 주년생산과 단위면적당 생산성을 증대시키면서 품질향상을 극대화시키는 것이라 할 수 있다. 특히, 시설원예의 주년생산과 관련하여 냉ㆍ난방에너지의 절약에 관한 많은 연구가 수행되어 왔으며, 현재 많은 냉ㆍ난방장치들이 실용화되어지고 있다. 그 중에서, 여름철의 적극적인 냉방방법으로 증발냉각방식, 히터펌프, 에어컨 등이 농가에 보급되어 널리 이용되고 있으나 항상 경제성에 있어서 문제점으로 제기되고 있으며 이런 경제적인 부담을 줄이고자 냉방장치의 보조적 수단으로서 차광시스템이 널리 이용되고 있는 실정이다. (중략)

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1999.11a
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• pp.95-99
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• 1999

자연에너지와 전기에너지를 조합하여 냉방과 난방을 수행할 수 있는 방법중의 하나로 히트펌프 이용기술이 있으며, 국내의 경우 히트펌프는 주로 냉방 또는 냉동을 목적으로 이용되고 있으나, 1980년 이후 전기가 풍부한 경제선진국을 중심으로 난방 또는 냉난방겸용의 히트펌프가 개발되어 주택, 빌딩, 온실 등의 공조시스템에 이용되고 있다. (중략)

• Journal of Practical Agriculture & Fisheries Research
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• v.6 no.1
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• pp.143-154
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• 2004

The value of daily heating degree hour(described as DH hereafter) is essential for calculating the heating load of a greenhouse during the winter months. Many researchers have so for proposed different models for estimating DH value. Models for estimating DH have been investigated DH(unit, ℃·h·year^-1) in this paper. The comparisons of standard and existed DH values were made to know the estimation error of each model proposed so far. The standard DH values and other proposed DH values have were obtained for the inside setpoint temperatures of 9, 13, 16 and 20℃ in greenhouse, estimated based on meterological data from 1961 to 2000 according to locals, and standard DH values were independent and existed DH values were dependent. Among the various model, the one developed theoretically by Mihara modified to author was the best fitting for standard DH values. The DH values were obtained for the inside setpoint temperature of 9, 13, 16 and 20℃ by Modified Mihara's model. A new DH contour line graph was proposed using Modified Mihara's model. Using the DH contour line graph, the DH values can be obtained easily for any setpoint according to local.

• Journal of Bio-Environment Control
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• v.29 no.4
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• pp.320-325
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• 2020

This study aimed to analyze thermo-keeping and economic feasibility by utilizing silica aerogel, which has been attracting attention as a new material, complementing the disadvantages of the conventional multi-layered thermal screen, and producing and installing multi-layered thermal screen. The multi-layered thermal screen used in the experiment was produced in two combinations using a non-woven fabric containing silica aerogel and measured and compared the temperature and fuel consumption changes due to differences in practice with the multi-layered thermal screen being sold and used on the market. Experimental results show that the temperature and relative humidity changes due to the differences of the multi-layered thermal screens in the single-span greenhouse and the multi-span greenhouse were small but remained almost the same temperature and relative humidity. It is judged that this shows that the multi-layered thermal screen using silica aerogel is not inferior to the conventional multi-layered thermal screen. As a result of a comparative analysis of heating energy, the aerogel-based multi-layered thermal screen reduced fuel consumption by about 15% in the single-span greenhouse and about 20% in the multi-span greenhouse compared to the conventional multi-layered thermal screen. It is clear that heating energy is saved as a greenhouse size and duration increase. It was found that the silica aerogel-based multi-layered screen was more breathable and warmer than the conventional multi-layered thermal screen, but It was found that the multi-layered screen used in the multi-span greenhouse was heavier and stiff compared with the conventional multi-layered thermal screen, indicating less workability and operability. Therefore, improvements were applied to the multi-layered screens used in the single-span greenhouses. It was confirmed that the replacement of internal insulation materials reduced thickness and improved stiffness so that there could be sufficient possibility for farmers to use.

• Journal of agriculture & life science
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• v.46 no.2
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• pp.179-190
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• 2012

This study was performed to obtain a heat saving effect and enhance the efficiency of a greenhouse by using a hot water piping in order to minimize the operating costs of a greenhouse as oil prices continue to rise. This method also reduces the likelihood of accidents caused by snowdrifts in regions with heavy snowfall. In general, the experimental plot was $2.0{\sim}6.0^{\circ}C$ higher than the control plot. When the skylight felt was opened, the minimum temperature was in the range of $3.0{\sim}12.0^{\circ}C$. Therefore, we judged that damage caused by snowdrifts may be prevented partly by active heating. The temperature difference inside of the greenhouse by height was insignificant. The maximum heating load of the greenhouse according to crop was respectively about $37,000kcal{\cdot}h^{-1}$ and $41,700kcal{\cdot}h^{-1}$. During the experiment, the heat value of each designed temperature in the range of the minimum ambient temperature $-11.9{\sim}4.0^{\circ}C$ was about 95,000~322,000 kcal and it was in the range of $6,050{\sim}20,900kcal{\cdot}h^{-1}$. If it is compared with the maximum heating load, it can be shown that about 15~56% of the heating energy can be supplied. The total heat value and the amount of power consumption were 2,629,025 kcal and 677.3 kWh respectively during the experiment. If it is heated with diesel, a fossil fuel, the consumption during the experiment was 291 L and the cost was 331,700won. Total cost of using electric power was about 24,400 won and it is shown that it is about 7.5% of the cost of diesel consumption. Also, if the total amount of power consumption is converted into energy, it is approximately 582,200 kcal and the energy was just about 22% of the total heat value.