摘要
为了摸清番茄果实与空气间传热的对流换热系数,在人工气候室控温、控光环境下,测定了番茄果实不同风速时的表面温度与空气温度的温差,根据热平衡原理计算番茄果实表面的对流换热系数。用Porter和Mitchell模式计算对流换热系数,并计算了模式的回归系数。用称重法测定1 d中番茄果实水分损失量,分析了番茄水分损失产生的潜热交换量。结果表明,采样后24 h内番茄果实水分蒸发产生的潜热交换量平均为2.3 W/m2;番茄果实的对流换热系数随风速增加而线性增加。Porter的模式回归系数修正后,可用Porter公式计算对流换热系数。这为以后的对流传热分析提供了较为确切的热物性参数。
To obtain the convection between tomato fruitage and air,the differences in temperature of tomato fruitage surface and air on controlled environment temperature,light intensity in different wind speeds were measured.The convection coefficient between tomato fruitage and air was calculated according to heat balance law,and kc,ks parameters of the models were calculated using Porter and Mitchell′s models.The influence of hidden heat coming from tomato water loss was analyzed through 24 h time interval weight loss of the tomato fruitage.The result showed the hidden heat of the tomato fruitage was 2.3 W/m2.The measurement result of the convection coefficient increased according to the increase of wind speed,which confirms the view point of former researchers about convection coefficient.It gives a definite parameter for convection heat analyses.Not only did this paper provide a measurement method of the convection coefficient,it settled a base for tomato fruitage climate space study also.
出处
《华北农学报》
CSCD
北大核心
2012年第6期229-232,共4页
Acta Agriculturae Boreali-Sinica
基金
国家自然科学基金项目(31071321)
