大尺寸平板太阳集热器集热效率研究

STUDY ON THERMAL EFFICIENCY OF LARGE-SCALE FLAT PLATE SOLAR COLLECTORS

平板型太阳集热器集热效率除了与内部结构参数、运行参数等因素有关外,还受集热器外形尺寸大小的影响。通过建立相同集热面积条件下单一大尺寸平板集热器、并联常规平板集热器的三维物理模型,分析了2类集热系统集热效率、集热量、热损失随尺寸规模的变化关系。发现相同集热面积条件下,相比并联常规平板集热器形式,大尺寸平板集热器集热效率有所增加,约增大4%;但对于常规并联平板集热器,随着并联面积增大其热损失所占比例均有所增大,集热效率也有一定的降低;而对于单一大尺寸平板集热器,随着外形尺寸增大,热损失所占比例降低,且集热效率有所升高。研究结论可对大型平板集热器的尺寸设计提供设计指导。

The collector efficiency of flat plate solar collector was affected by the size of the collector in addition to the internal structural parameters,operating parameters and other factors.3-D physical models of large-scale flat plate solar collectors and parallel conventional flat plate collectors under the same heat-collecting area were established.Moreover,the relationship between the collector efficiency,heat collecting capacity and the heat losses with the change of scale of the two types of collector systems was studied and analyzed.It was found that under the same heat collecting area condition,the collector efficiency of the large-scale flat plate solar collector was increased about 4%compared with the parallel conventional flat plate collector.However,for the conventional flat plate collectors in parallel,the proportion of heat losses was increased and the collector efficiency was decreased to a certain extent with the increase of heat collecting area.On the other hand,the large-scale flat plate collectors the heat loss was decreased and the collector efficiency was increased with the increase of heat collecting area.The research conclusions could provide guidance on the size design of large-scale flat plate collectors.