全流道式平板型太阳能集热器的试验研究与模拟分析

Experimental investigation and numerical simulation study on full-channel flat plate solar thermal collector

以全流道式平板型太阳能集热器为研究对象,首先进行了集热性能试验测试,在此基础上,利用CFD技术对不同排管管径全流道吸热板内传热介质的流动与传热进行模拟。试验结果表明,全流道集热器集热性能好、保温性能优,最高瞬时集热效率可达86.1%,热损失系数仅为4.179 W/(m^2·℃);与有关国家标准比较,最高瞬时集热效率高14.1%,热损失系数低1.82 W/(m^2·℃)。模拟结果表明:全流道板芯在增大流体传热接触面积的同时产生了横向导流作用,使各排管间流体流量分布更为均衡;全流道板芯热阻小,壁面上热流分布均匀,有效地增大了板芯的对流换热。

A full-channel flat plate solar thermal collector（also completely flooded absorber） is studied in this paper. Firstly, a test on the collector performance of capturing solar radiation has been carried out. Then, the flow of heat transfer medium and heat transfer in different diameter pipe of full-channel absorber plate are simulated by CFD technology. The results show that the full-channel heat absorbing plate has strongly absorbing performances, good insulation properties, and the maximum instantaneous absorbing efficiency is up to 86.1% and the heat loss coefficient is only 4.179 W/（m^2·℃）,14.1% higher and 1.82 W/（m^2·℃） lower than those of the national standard. In addition, a lateral diversion role is produced while the full-channel plate increases the contact area of the heat transfer fluid, which promotes more balanced distribution of the fluid flow among the calandrias. The well-distributed heat flow and lower thermal resistance on the full-channel plate core wall can increase the convective heat transfer efficiency.