Development of Rain Shelter for Chinese Cabbage Rainproof Cultivation

Abstract

This study was carried out to develop rain shelter which can make an appropriate size and environment for Chinese cabbage rainproof cultivation. Fifty three farms with chinese cabbage rainproof cultivation system have been investigated to set up width and height of rain shelter. Mostly the width of 6m was desired for rain shelter and the height of 1.6m for their eaves, so these values were chosen as the dimensions for rain shelter. After an analysis of their structural safety and installation costs by the specifications of the rafter pipe, Ø25.4×1.5t and 90cm have been set as the size of rafter that such size costs the least. This size is stable with 27m•s −1 of wind velocity and 17cm of snow depth. Therefore it is difficult to apply this dimension to area with higher climate load. In order to sort out such problem, the rain shelter has been designed to avoid damage on frame by opening plastic film to the ridge. Once greenhouse band is loosen by turning the manual switch at the both sides of rain shelter and open button of controller is pushed then switch motor rises up along the guide pipe and plastic film is opened to the ridge. Chinese cabbage can be damaged by insects if rain shelter is opened completely as revealed a field. To prevent this, farmers can install an insect-proof net. Further, the greenhouse can be damaged by typhoon while growing Chinese cabbage therefore the effect of an insect-proof net on structural safety has been analyzed. And then structural safety has been analyzed through using flow-structure interaction method at the wind condition of 40m•s −1 . And it assumed that wind applied perpendicular to side of the rain shelter which was covered by insect-proof net. The results indicated that plastic film was directly affected by wind therefore high pressure occurred on the surface. But wind load on insectproof net was smaller than on plastic film and pressure distribution was also uniform. The results of structural analysis by applying pressure data extracted from flow analysis indicated that the maximum stress occurred at the end of pipe which is the ground part and the value has been 54.6MPa. The allowable stress of pipe in the standard of structural safety must be 215 MPa or more therefore structural safety of this rain shelter is satisfied.

Damage index estimation by analysis of meteorological disasters on film plastic greenhouses

“…Studies were also conducted on the development of safe greenhouses suitable for crop cultivation considering heavy rain, wind, and snow loads. Yu et al [11] investigated the specifications of a greenhouse for crop cultivation and developed a structurally embedded multi-span greenhouse that meets the design standards [12,13] .…”

Effect of Combined Pallet Unit MAP and Plasma Treatment for Extending the Freshness of Spring Kimchi Cabbage

“…최근 기후 온난화로 인하여 점차적으로 온도가 상승하고 잦은 이상기상으로 인하여 작 황이 매우 불안정하다 Lee et al, 2012). 그래서 연차 간에 수급이 불안정하고 가격 차이가 심한데, 신선채소 가격이 연일 폭등하던 2010년에는 배추 가격이 2009년에 비해 197%까지 급등하기도 했다 (Yu et al, 2014). 배추는 생산량 변 동에 따라 가격편차가 매우 크기 때문에 10% 정도의 생산량 변동만으로도 가격은 3배까지 차이가 날수가 있다 (Kim et al, 2015).…”