摘要
提出一种内置式PV-Trombe墙结构,并运用CFD技术对垂直入口内置式PV-Trombe墙在宽度变化时的自然通风和对流换热进行数值模拟。结果表明,烟囱内气流的温度与速度沿着烟囱通道宽度的方向变化很不均匀。在太阳电池表面存在一个空气温度和速度边界层,使得局部的温度梯度和速度梯度较大。烟囱的通风量随着宽度的增加先逐渐增加到一个极大值,然后随宽度的继续增加而减小。对于该文模型,获得最大通风量的最佳的烟囱的宽度与高度的比为(d/H)_(opt)=1/5。随着宽度的增加,烟囱的自然对流换热增强,空气对电池表面的冷却效果得到改善,因而PV的发电效率略有增加。对多组条件下的计算结果进行多元线性拟合,得到表征通风量与传热特性的无量纲参数Nu数、Re数随Ra*变化的拟合公式,为自然通风设计提供依据。
A novel built-in PV-Trombe wall with vertical inlet was proposed and the natural convective heat transfer and natural ventilation was numerically simulated based on computational fluid dynamics （CFD） method for different channel widths. Results showed that the air temperature and velocity along the channel width was very uneven. On the surface of the PV, there were a thermal and velocity boundary layers, which resulted to higher temperature and velocity gradients. The ventilation rate through the built-in PV-Trombe wall increased first to a maximum value as the channel width increased, then decreased as the channel width increased further. In the present model, the optimal ration of the channel width to the channel height, （d/H）op, = 1/5 to gain the maximum ventilation rate. As the channel width increased, the natural convective heat transfer was enhanced and the PV surface was better cooled by the air which improved the PV electricity efficiency slightly. A muhivariable regression analysis was used to correlate the calculated results of several cases. Dimensionless expressions to calculate the rate in term of a Reynolds number were correlated natural ventilation design. averaged heat transfer coefficient, Nusseh number, and the air flow according to a modified Rayleigh number, which could be used to the natural ventilation design.
出处
《太阳能学报》
EI
CAS
CSCD
北大核心
2015年第7期1710-1716,共7页
Acta Energiae Solaris Sinica
基金
国家自然科学基金(51278095)
上海市自然科学基金(11ZR1401000)
作者简介
通信作者：苏亚欣（1972-），男，博士、教授，主要从事建筑暖通空调能源利用与节能等方面的研究。
