초록 ▼

Ⅳ. 연구개발결과
연동온실의 곡부는 지붕의 2배 하중이 적용되었으며, 눈에 미끄러져 슬립이 발생하지 않도록 원뿔 모양 스터드가 달린 구동 롤러가 모노레일을 따라 이동하는 제설대차 방식을 선정하였으며, 제설대차의 마찰계수와 눈의 전단계수를 측정하고 소요 동력을 산정하였음. 조설 장치가 설치된 농업공학부 항온항습실에서 1/10의 적설하중을 1/16 동력으로 제설할 수 있었음. 또한 농업공학부 포장에 20 m 연동온실 곡부를 설치하고 13 cm 눈이 적설 되었을 때 성능시험을 수행한 결과 제설이 가능하였음. 또한, 온수 보일러 이용

Ⅳ. 연구개발결과
연동온실의 곡부는 지붕의 2배 하중이 적용되었으며, 눈에 미끄러져 슬립이 발생하지 않도록 원뿔 모양 스터드가 달린 구동 롤러가 모노레일을 따라 이동하는 제설대차 방식을 선정하였으며, 제설대차의 마찰계수와 눈의 전단계수를 측정하고 소요 동력을 산정하였음. 조설 장치가 설치된 농업공학부 항온항습실에서 1/10의 적설하중을 1/16 동력으로 제설할 수 있었음. 또한 농업공학부 포장에 20 m 연동온실 곡부를 설치하고 13 cm 눈이 적설 되었을 때 성능시험을 수행한 결과 제설이 가능하였음. 또한, 온수 보일러 이용, 전기 온상선 이용, 나노 히팅 파이프 이용, 온풍 난방기 덕트 이용, 분수호스 이용 등 5가지 방법에 대하여 융설 효과를 시험하였고, 온풍난방기 덕트 처리구가 실내와 현장 설치 시험에서 가장 우수한 것으로 나타남. 온풍난방기 덕트 처리구에서 상대적으로 효과가 큰 것으로 나타난 것은 비닐하우스 내부에 축적된 열이 곡부 물받이 판에 면상으로 전달되면서 위에 쌓인 눈을 녹인 것으로 추정됨. 연동온실의 설계 적설심에 따른 곡부 쌍꽂이 선택기준과 쌍꽂이 이외의 곡부 하중 내력 강화 방안을 제시하였음

Abstract ▼

RDA developed and disseminated the standard design and specification for horticultural facilities to minimize losses from climatic disaster. A safe depth of snow cover for multi-span greenhouse was between 53 cm and 57 cm by regional groups. However, recently a depth of snow was more than the safety

RDA developed and disseminated the standard design and specification for horticultural facilities to minimize losses from climatic disaster. A safe depth of snow cover for multi-span greenhouse was between 53 cm and 57 cm by regional groups. However, recently a depth of snow was more than the safety depth in local. For example the depth of snow in Daegwallyeong was 126.2 cm in 2005, Donghae 102.9 cm in 2011 and Gangneung 110 cm in 2014. Specifically the snow load on valley of multi-span greenhouse is more dangerous than roof because the snow load on valley is between 1.5 and 3 times more than on the roof. Therefore, the mechanical and melting devices removing the snow on the valley and preventing losses of structure were studied. The results were as follows:
1. The existing results which researched removal of the snow on the greenhouse were inspected. Merits and demerits were compared. The electric motor powered vehicle which is driven through driving roller with studs on the monorail was selected.
2. The coefficient of friction between the driving roller and the monorail and shear factor between sliced horizontal sections of snow was measured at constant temperature and humidity room in National Academic of Agricultural Science. Test results showed that the shear factor of the snow was between 1.60 and 2.37, and the coefficient of friction was linearly proportional to the travelling speed of the vehicle.
3. The required motor power to remove the snow was calculated against 100 m length and 2 cm depth of snow cover and was 2 kW except safety factor. Small scale vehicle was driven with 90 W power and removed the 1/10 snow load. Outdoor test was performed at 15 cm depth of snow on multi-span green house. The snow was removed clearly.
4. Five snow-melting systems which consisted of a hot-water boiler, a electric heating wire, a nano heating pipe, a hot-air duct and a fountain pipe were set up and tested in the constant temperature and humidity room. They were set up and tested on the valley of multi-span greenhouse.
5. Test results showed that the hot air duct had the most impact on the snow-melting system because the accumulated heat inside the greenhouse was transferred to a scupper and melted the snow.
6. In order to reinforce the structure, pair insert must be inserted on the connected greenhouse according to depth of snow cover in region, two fixing pipes must connected or a bent of rafters must be propped up with a movable pipe.