|关键词: 日光温室 后墙 放热量 放热机理 驱动 被动放热
|Theoretical analysis on difference of heat-releasing volume at different height of the back Wall in solar greenhouse at Night
ZHANG Chuankun, WEI Min1, LIU Fusheng2, 徐平丽 3, LI Yan1
1.Horticulture and engineering college,Shandong agricultural university;2.College of water conservancy and civil engineering,Shandong agricultural university;3.Bio-tech Research Centre of Shandong Academy of Agricultural Sciences
|Aiming at the phenomenon that the heat-releasing volume of the back wall at different heights in solar greenhouse were quite different, this study first deduced the heat-releasing mechanism of the back wall formed by the outer low temperature through greenhouse cover with the physics vector principle and the gas molecular movement theory as foundation, and then analyzed the heat-releasing data of back wall under the guidance of heat-releasing mechanism, improving the theory of heat-releasing from the back wall and providing theoretical basis to improve the temperature environment of greenhouse. The results showed that the temperature of the back wall decreases continuously after releasing heat, and the heat-releasing volume from the back wall increased gradually from the top side to the bottom side, and the heat-releasing volume from the bottom side was 2~3 times higher than that from the top side. The data analysis shows that the deduced exothermic mechanism can explain the heat-releasing difference at different height of the back wall, and the heat release of the back wall is a passive heat release process driven by the external low temperature. The heat-releasing volume is affected by the heat release drive and the temperature of the back wall when the temperature of back wall is high, and the heat-releasing volume in the middle of the back is also much; the heat-releasing volume of the back wall is mainly driven by the heat release drive of the back wall when the temperature of the back wall is low.
|Key words: solar greenhouse back wall heat-releasing volume exothermic mechanism drive passive heat release