Study On Performance In Asymmetric Water Control Fermentation Plastic Greenhouse

Greenhouse is one of the main agricultural facilities which is widely used in northern China.In order to improve the land use rate,unit area cost and thermal insulation property.Most scholars studied and proved on the strure of greenhouse.This paper mainly studied on the property of Large-span Asymmetric Water Control Fermentation Plastic Greenhouse(GH-F),Large-span Double-covered Plastic Greenhouse(GH-D) and Common Sunlight Greenhouse(GH-P) in Shanxi Yangling.Environmental parameters such as temperature, humidity and light intensity of the three greenhouses were monitored. Then the paper analyzed the heat transfer of Large-span Asymmetric water control fermentation plastic greenhouse,and found out the main way of heat loss.The main results were as follows:1.Temperature of January:mean temperature: GH-F 14.2℃, GH-D 10.9℃, GH-P 14.6℃.Maximum temperature: GH-F 36.8℃, GH-D 34.8℃, GH-P 36.5℃.Minimum temperature:GH-F 4.3℃, GH-D 2.2℃, GH-P 4.0℃.Clear days in winter,As span increased,the temperature distribution in the horizontal direction were not uniform in GH-F and GH-D.Overcast day and snowy weather, the temperature distribution in the horizontal direction were no significant differences.2. The characters of different illumination conditions in three greenhouses were studied.As span increased,the temperature distribution in the horizontal direction were not uniform in Asymmetric Water control fermentation Greenhouse and Double-covered Plastic Greenhouse.3.Clear days in winter, relative humidity of three greenhouse in daytime were:45.2%,49.1%,47.5%; at night, were around 80%-85%.Overcastday and snowydays were about 90%.4.Large-span asymmetric water control fermentation plastic greenhouse’s soil was the biggest heat retainer that can storage heat in daytime and release heat at night; heat dissipating capacity of the north roof wer account for 40.7% in total,light surface was 53.4%.