PVT墙流道结构优化的数值模拟研究

Numerical study on the optimization of air channels in PVT wall

为了确定PVT墙的最优流道结构,建立了4种流道类型PVT墙的数学模型(分别命名为M1~M4),并进行热/电性能的比较分析。首先,通过与文献报道的关联式进行对比,证实了所建立数学模型的准确性。其次,分析了流道结构对集热效率、发电效率以及[火用]效率的影响。结果表明:流道结构对PVT墙的性能有显著影响。M4在集热效率方面表现最佳,当空气流量为3.7×10^(-2) kg/s时,达到了44.06%。在发电效率方面,M1表现最佳,其次为M3和M2,M4最低。在[火用]效率方面,当空气流量小于0.0184 kg/s时,M1的[火用]效率最高;当空气流量超过0.0184 kg/s时,M3的[火用]效率最高。由此可以发现,很难做到在一种PVT墙的流道结构内同时达到高发电效率与集热效率,但综合考虑PVT墙产生的能源数量与质量,可以认为M3的结构最佳。

In order to determine the optimal flow channel structure for PVT(Photovoltaic-Thermal)walls,mathematical models are established for four different types of flow channels(designated as M1~M4),and comparative analysis is conducted on their thermal/electrical performance.Firstly,the accuracy of the mathematical models is confirmed by comparing them with correlations reported in the literature.Secondly,the influence of the flow channel structure on the collection efficiency,electricity generation efficiency,and exergy efficiency is analyzed.The results indicate that the flow channel structure significantly affected the performance of PVT walls.M4 performed the best in terms of collection efficiency,reaching 44.06%when the air flow rate is 3.7×10^(-2)kg/s.In terms of electricity generation efficiency,M1 performed the best,followed by M3 and M2,with M4 being the lowest.Regarding exergy efficiency,when the air flow rate is less than 0.0184 kg/s,M1 shows the highest exergy efficiency;while when the air flow rate exceeded 0.0184 kg/s,M3 exhibites the highest exergy efficiency.It is thus difficult to achieve high electricity generation efficiency and collection efficiency simultaneously within the flow channel structure of a single PVT wall.However,considering both the quantity and quality of energy produced by PVT walls,the structure of M3 could be considered the best.