Study On Double-layer Inflated Film Covering In Greenhouse

In total agricultural system, facility horticulture is an energy-costing industry. To deal with energy problem in product, we should increase the insulation performance of greenhouse. Double-layer inflated film covering is a simple type of heat preservation in greenhouse. Its advantage lies in its good insulation performance and simple operation. It is a direction of covering technique in greenhouse. According to the measurement principle of the stabilized heated box, two insulated model heated boxes were built in this thesis. Though experiments, the influence of temperature difference between inside and outside of box, property of cladding material, the thickness of air, wind speed and net radiation in night on heat transfer coefficient was determined. At the same time, I compared the insulation performance of double- layer inflated film and single-layer film. In order to compare the insulation performance of different materials, this paper put forward the standard condition to determine the heat transfer coefficient. The overall heat-transfer coefficients of double-layer inflated film and single-layer film in standard condition were calculated. Theoretical calculation validated the experiment with model boxes. In addition, the insulation performance of double-layer inflated film and single- layer film greenhouse were compared though measurement in real greenhouses. Though measurement in model greenhouses, I compared the light in double-layer inflated film greenhouse and single-layer film greenhouse. Though experiment in real greenhouses, the connection of solar transmission performance and condensation and cleanness of material was determined. Finally, this paper compared the total investment in double-layer inflated film greenhouse and single-layer film greenhouse and put forward the localization of double- layer inflated film greenhouse.