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出 处:《长江蔬菜》2013年第8期21-26,共6页Journal of Changjiang Vegetables
基 金:河北省"十一五"科技支撑计划项目(07220701D)
摘 要:以日光温室空间地面作物受光点为核心,根据半地下立窗型日光温室的结构特点,建立日光温室采光性能实用型优化的数学模型,并以定州地区(北纬38°31')为例,根据温室平均采光效率ηs、采光屋面保温效率τ和有效升温效率υ、温室采光面下土地使用效率φ4个评价参数,结合模型模拟运算结果进行了实用型优化。结果表明,半地下立窗型日光温室前屋面的曲线类型可以在立窗+圆弧面、立窗+椭圆面和立窗+抛物线面3种采光面中任选其一;日光温室内跨和半地下深度对ηs和τ的影响较大,半地下深度超过30 cm时,τ呈线性锐减趋势;脊高增加,υ呈线性锐减趋势;脊高和内跨增加,则φ呈明显线性增加趋势;立窗高度增加,则φ呈明显线性增加且最后呈饱和趋势;半地下深度超过75 cm时,φ呈线性锐减趋势。据此,半地下立窗型日光温室的优型结构参数选定为:脊高以340~360 cm为宜、日光温室内跨以900~1 000 cm为宜、立窗高度以75~115 cm为宜、半地下深度以30~45 cm为宜。Taking light acceptance spots of crops in solar greenhouse as the core, a practical optimized mathematic model of lighting performance was established according to the structural characteristics of semi-underground vertical window type solar greenhouse. Taking Dingzhou region (north latitude 38°31') for example, the results of practical optimization combined with model simulation showed that, we could chose one of three lighting roof curve types for semi-underground vertical window type solar greenhouse optionally, including vertical window+arc surface, vertical window+elliptical surface and vertical window+parabolic surface, according to four evaluation parameters, average lighting efficiency in greenhouse ηs, insulation efficiency of lighting roof (τ), effective temperature-rising efficiency (v) and soil utilization ratio φ. The internal span and semi-underground depth had great influence on ηs and τ.τ showed a linearly decreasing trend when the semi-underground depth exceeded 30 cm, and v decreased linearly as the ridge height increased. φ showed an obviously linearly increasing trend as the ridge height and intemal span increased, and as the vertical height increased, φ obviously increased linearly and finally reached the saturation value, however, φ decreased linearly when the semi-andergroand depth exceeded 75 cm. Accordingly, the optimum structural parameters, ridge height, intemal span, vertical window height and semi-underground depth of semi-underground vertical window type solar greenhouse were 340-360 cm, 900-1 000 cm, 75-115 cm and 30-45 cm, respectively.
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