Study On The Physical Design And The Warming And Thermal Insulation Properties In The Solar Greenhouse Of Different Span

The span of greenhouse affects the land use rate, unit area cost, lighting capacity andthermal insulation property. Actually, the larger span leads to the higher land use rate andlower unit area cost, but the lighting capacity and thermal insulation property declining. Thespan of solar greenhouse was6.5m to7.5m in the early development stage in GansuProvince, while the span of new greenhouse was8.0m to8.5m. All these greenhouses cannot adapt the requirement of upsizing structure and simplified greenhouse operation. In thisstudy, the stone wall and steel-work solar greenhouse of four different span (8,9,10,11meters)was designed and constructed in Suzhou District, Jiuquan City to improve greenhouse spaceand properties. By the comparison of the thermal insulation properties of four greenhouses during the winter (from2012to2013and from2013to2014), the study expect to screen outsuitable solar greenhouse structure for Hexi Corridor in Gansu Province. The test results ofthermal insulation property were as follows:1. In early winter (mid to late November)2012, compared to control, the averagetemperature of four test greenhouses were increased by0.63-1.66℃, the average maximumtemperature was reduced by7.17-4.84℃and the average minimum temperature was increasedby2.53-3.70℃. During the winter (From November2012to February2013), the days ofminimum night temperature under5℃and8℃lasting more than1h of four test greenhouseswere2d,1d,0d and8d, and20d,20d,14d and41d, respectively.2. In overwintering stage (from November2013to February2014), compared to control,the average temperature of four test greenhouses were increased by0.84-3.39℃, the averagemaximum temperature was reduced by4.98-4.07℃and the average minimum temperaturewas increased by0.42-2.47℃. The days of minimum night temperature under5℃and8℃lasting more than1h of four test greenhouses were5d,4d,0d and10d, and21d,21d,15dand43d, respectively.