北方日光温室北墙和后坡热通量日变化的谐波特征

为了确定日光温室北墙和后坡热通量日变化的谐波组成与相应周期,采用谐波分析法,以辽沈Ⅰ型日光温室为研究用温室,分别进行了有无作物条件下的试验.结果表明,无作物区日变化曲线由以π/72、π/36和π/24为周期的正弦曲线组成；作物区日变化曲线由以π/72、π/36为周期的正弦曲线组成,作物明显影响了日光温室北墙和后坡热通量日变化的谐波成分和相应周期.其中选定谐波所占比重均达到90％以上,说明日光温室北墙和后坡的热通量日变化可以用相应周期的谐波组合表达,并且可以利用谐波分析法进行日光温室热通量的日变化特征的研究.

Harmonic Characteristics of Heat Flux Diurnal Variation of North Wall and Back Slope in Northern Solar Greenhouse

To investigate harmonic component and corresponding period of heat flux diurnal variation on north wall and back slope in solar greenhouse, the experiment was eondueted with Liaoshen Greenhouse Ⅰ under different conditions with crops and without crops by using Harmonic analysis method. The results showed that diurnal variation curve was composed of sinusoids by π/72, π/36 and π/24 cycles without crops, and by π/72 and π/36 cycles with crops. Crops affected harmonic component and corresponding period significantly. Moreover, investigated harmonic aceounted for more than 90%, which indicated that heat flux diurnal variation on north wall and back slope could be expressed by harmonic component during corresponding period, and harmonic analysis could be used to research for heat flux diurnal variation in solar greenhouse.