下挖式日光温室夜间土壤非稳态导热过程

Soil unsteady heat conduction process in deep-bed solar greenhouse at night

针对日光温室土壤温度不均衡的问题,运用传热学非稳态导热理论,测定分析跨度方向上不同测点地面温度变化率和土壤放热量之间的关系,对下挖式日光温室土壤夜间的非稳态导热过程进行研究。结果表明:1)日光温室地面放热量受地面温度和跨度位置综合作用,地面温度越高、跨度位置越大,土壤放热量越多;2)不同测点地面温度变化率和土壤放热量不成比例,土壤存在水平方向上的热量流动;3)土壤边际效是受到后墙下土壤、温室外土壤缓冲作用引起的;4)本试验中,受后墙下土壤缓冲,土壤放热增加量占土壤放热量比例为6.06%～7.34%;受温室外土壤缓冲,土壤放热减少量占土壤放热量比例为31.8%～50.28%;边际效应对土壤温度环境具有不利影响。

In view of the imbalance of soil temperature, this study analyzed the relationship between the change rate of temperature and soil heat-releasing volume of test points in span direction with unsteady heat conduction theory as foundation and took deep-bed solar greenhouse as trial subject, and conducted research on the process of the soil unsteady heat conduction. The results showed that the heat-releasing volume was affected by the ground temperature and the span position. The higher the surface temperature and the larger the span position, the more heat was released. The change rate of temperature and the heat-releasing volume were not proportional, and there was heat flowing in horizontal direction. The marginal effect of soil was caused by buffer from the soil under the back wall and the soil outside the greenhouse. In this experiment, the heat-releasing volume increased by soil buffer under the back wall was 6.06%-7.34% of total soil heat-releasing volume, and the heat-releasing volume reduced by soil buffer from outside greenhouse was 31.8%-50.28% of total soil heat-releasing volume. The marginal effect had a negative effect on the soil temperature environment.