• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2003.07a
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• pp.238-246
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• 2003

우리나라 농산물 저온저장고 설치비 중 70% 이상이 저장고내 열관리를 위한 자재와 설비에 소요되며, 저온저장고의 가동에는 많은 에너지가 소요되므로 열관리 설비 및 에너지 비용의 최소화로 저온저장 비용을 절감화 시킬 필요가 있다. 더욱이, 우리나라는 에너지의 대부분을 수입에 크게 의존하는 나라로 에너지를 효율적으로 관리하는 것이 매우 중요하다. (중략)

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.617-626
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• 1993

Energy saving is a very important subject for research workers nowadays. While most people are concerning with the modern methods, the authors investigated this problem from another angle- the chinese traditional methods of energy saving. The tunnel with technique and its combination with computer simulation and fuzzy compressive judgement methods are discussed. Earth heat green house, marsh gas, solar energy underground storage system, storing of nature cold sources, have been introduced in this paper.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.627-636
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• 1993

The so-called northern Agricultural Engineering of Farmer's courtyard Energy Ecological System is a courtyard-type energy ecological synthetic application system, that combines into one the biogas pool, pig house, toilet and plastic -membrane greenhouse in a fully-closed condition in farmer's court yard, a combination of farming with breeding industry, with bioga as the key linkage , by taking full advantage of solar energy and through bioenergy conversion technique in accordance with ecological principle.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• v.10 no.1
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• pp.341-344
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• 2005

• Journal of Biosystems Engineering
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• v.28 no.3
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• pp.225-230
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• 2003

This study was carried out to analyze the environmental variation of layer house at Iowa State in the USA. The analyzed seasons for this study were summer and winter. Analyzing factors are inside temperature and relative humidity, carbon dioxide concentration, ammonia concentration and emission. All factors were collected every 30 second from each house with portable monitoring units. In this study, two types of laying hen houses were monitored at the same season. One was a manure belt house, the other was a high-rise house. In order to estimate the ventilation rates of the laying hen houses, carbon dioxide concentration balance was used in this study. Ammonia concentrations and emission rates of the manure belt house are much lower than those of the high rise house. Daily mean ammonia concentrations in the manure belt house and high-rise house ranged from 3 to 7 ppm and 5 to 34 ppm, respectively. The daily ammonia emission rates averaged 0.68g/h$\cdot$500kg and 0.73g/h$\cdot$500kg for the manure belt house and 0.93g/h$\cdot$500kg and 2.89g/h$\cdot$500kg for the high-rise house in summertime and wintertime, respectively. Summertime is associated with much higher ammonia emission rates than wintertime because of much higher ventilation rates and ambient air temperature, even though the concentrations may be lower.

• The KSFM Journal of Fluid Machinery
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• v.15 no.2
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• pp.20-29
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• 2012

The green house on the waterfront is air-conditioned by a water-source heat pump system with riverbank filtration water. In order to supply riverbank filtration water in alluvium aquifer, the riverbank filtration facility for water intake and recharge, two pumping wells and one recharge well, has been constructed. The research site in Jinju, Korea was chosen as a good site for riverbank filtration water supply by the surface geological survey, electrical resistivity soundings, and borehole surveys. In the results of two boreholes drilling at the site, it was revealed that the groundwater table is about 3 m under the ground, and that the sandy gravel aquifer layer in the thickness of 6.5 m and 3.5 m occurs at 5 m and 7 m in depth below the ground level respectively. To prevent the recharge water from affecting the pumped water which might be used as heat source or sink, the distance between pumping and recharge wells is designed at least 70 m with a quarter of recharged flow rate. It is predicted that the transfer term, the recharge water affects the pumping well, is over 6 months of heating season. Hydrogeological simulation and underground water temperature measurement have been carried out for the pumping and recharge well positions in order to confirm the capability of sustainable green house heating and cooling.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.487-494
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• 1993

In order to establish a fully automatized pest control in the a greenhouse , the authors developed a prototype of microcomputer installed spraying vehicle which traveled along the furrows. Since a power sprayer mounted on the vehicle was driven by gasoline engine, plants grown in the greenhouse might be injured by the gas exhausted from the engine. Thus , effects of exhausted gas on photosynthetic rate and the shedding of flowers and buds of plants were examined. At first, effects of exhausted gas on photosynthetic rate of potted sweet pepper (Capsicum annuum L.) and eggplant(Solanum melongena L.) plants were examined. In a closed vinyl house the engine was operated for 5 minutes and plants were exposed to the gas for 2hours in the daytime on a fine day. Photosynthetic rate did not significantly decreased by the treatment in both species. Secondly, effects of ehtylene on the shedding of flowers and buds of sesame (Sesamum indicum L. ) were examined. In the closed and partiall opened vinyl house, the engine was operated for 5 minutes and potted sesame plants were exposed to the gas for 12 hours in the night. In partially opened vinyl house, ethylene concentration decreased to 0 ppm 3 hours after the engine was stopped and flower and bud did not shed. In contrast, when vinyl house was closed ethylene concentration was 0.75 pm even 12 hours after the engine was stopped and flowers and buds shed markedly and epinasty was observed in upper young leaves. As mentioned above , it was revealed that injury of plants in the greenhouse caused by the gas exhausted from a gasoline engine could be prevented by providing suitable ventilation.

• Journal of Biosystems Engineering
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• v.26 no.4
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• pp.323-330
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• 2001

The regular maintenance and repair status of major farm machinery such as power tiller, farm tractor, rice transplanter and combine harvester etc., were surveyed and analyzed for the full-time farmers in order to get basic information for promoting farm machinery productivity. The survey was carried out through 209 farmers from 9 provinces. The results of this study can be summarized as follows; 1. The regular maintenance of farm machinery was conducted at repair shop(49.5%) or dealer agency(12.0%), and also conducted by farmers at their house(34.9%). 2. For the status on the cleanness or exchange times of engine oil, fuel filter and air cleaner, most farmers conducted fewer times than the necessary times. And, 5.3%, 7.7%, and 2.9% of surveyed farmers experienced breakdowns due to the insufficient cleanness or exchange oil, fuel filer, and air cleaner, respectively. 3. Most farmers(76.1%) recognized the necessity of farm machinery training or education, and they preferred one week for the training period, simple or easy maintenance for the training level, agricultural technical center or farm machinery manufacturer for the training agency. 4. Complete recognition of operation manual and sufficient maintenance before-, during-, and after-operation for the farm machinery can minimize the breakdowns, enlarge the endurance prevent the safety accidents, and promote productivity of farm machinery. And, these can be accomplished by the thorough training or education for agricultural machinery.

• Journal of Biosystems Engineering
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• v.34 no.1
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• pp.63-68
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• 2009

This study was carried out to determine necessary conditions for optimal ventilation of small windowless piglet house (5.2 (W) ${\times}$ 12.3 (L) ${\times}$ 2.3 (H) m) with negative tunnel ventilating system using CFD (Computational Fluid Dynamics) simulation. The weaning piglet house for this experiment was consisted of 4 rooms (520 (W) ${\times}$ 300 (L) cm), 3 fences (70 (H) cm), 1 air inlet (350 (W) ${\times}$ 2 (H) cm) and 1 exhaust fan (50 (D) cm), and simulated using CFD code, FLUENT. The simulation results for the original weaning piglet house showed ununiform ventilation for each room. Therefore, to uniformly ventilate all rooms, the heights of the air inlet and first fence were modified to 3 cm and 100 cm, respectively. The simulation result f3r the modified weaning piglet house showed uniform ventilation for all rooms and the optimum air inlet velocity of 1.4 m/s.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.6
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• pp.667-672
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• 2023

This study proposes polymer electrolyte membrane fuel cell (PEMFC) based cogeneration system for greenhouse heating and cooling. The main scope of this study is to examine the proposed cogeneration system's suitability for the 660 m²-class greenhouse. A 25 kW PEMFC system generates electricity for two identical air-cooled heat pumps, each with a nominal heating capacity of 70 kW and a cooling capacity of 65 kW. Heat recovered from the fuel cell supports the heat pump, supplying hot water to the greenhouse. In cooling mode, the adsorption system provides cold water to the greenhouse using recovered heat from the fuel cell. As a result, the cogeneration system satisfies both heating and cooling capability, performing 175 and 145 kW, respectively.