一种槽式太阳能空气集热器热性能的试验研究

Experimental study on thermal performance research of a trough solar air collector

为了研究日光温室用槽式太阳能空气集热器的热性能,基于TracePro光学模拟软件设计了一种槽式太阳能空气集热器,对其进行试验研究,分析了不同因素对集热性能的影响规律。实验结果表明,管中空气流速的变化对集热器集热效率和集热量的影响规律是相同的,在不同的流速下,存在最佳空气流速约为4.4 m/s,使得集热器的集热量和集热效率最大,集热量达到373.2 W,集热效率约为25%,此时集热性能最好。对于不同太阳辐照度,正午时刻之前,太阳辐照度越大,集热器的集热效率越大,正午时刻之后,集热器的集热效率基本保持不变,15:40之后集热器集热效率逐渐减小。当太阳辐照度和管中流速相同时,室外温度越高,集热器集热效率越大,集热性能越好。集热管中空气温度沿着集热管出口方向不断增大,太阳辐照度越大,集热管相同位置空气温度越高。该研究结果可为此种槽式太阳能空气集热器在日光温室的应用中提供参考。

In order to study the thermal performance of trough solar air collectors used solar greenhouses,a trough solar air collector was designed based on TracePro optical simulation software, and experimental research and analysis was conducted for the influence of different factors on thermal performance. The experimental results show that the air flow rate in the tube has the same effect on the thermal efficiency and heat collection of collector. Under different flow rates, there is an optimum flow rate of 4.4 m/s, which makes the heat collector and heat collection efficiency of the collector the largest. It is 373.2 W, and the heat collecting efficiency is 25%. At this time, the heat collecting performance is the best. For different solar irradiances, before the noon time, the greater the solar irradiance, the greater the heat collecting efficiency of the collector. After the noon time, the collector efficiency of the collector remains basically the unchanged, and the collector set after 15:40,the thermal efficiency is gradually reduced. When the solar irradiance is the same as the flow rate in the tube, the higher the outdoor temperature, the greater the heat collecting efficiency of the collector, and the better the heat collecting performance. The air temperature in the heat collecting tube increases continuously along the outlet direction of the heat collecting tube, and the greater the solar irradiance, the higher the air temperature at the same position of the heat collecting tube. The results of this study can provide a reference for the application of such trough solar air collectors in solar greenhouses.