不同布置方式下真空管太阳能集热器的热性能以及入射角修正系数的对比试验研究

A comparative experimental study on thermal performance and incident angle modifier of two evacuated tube solar collectors arranged in different ways

为了获得真空管太阳能集热器布置方式对其热性能及入射角修正系数的影响规律,文章在室外条件下进行了2组真空管太阳能集热器性能试验。其中:一组试验为真空管太阳能集热器垂直放置;另一组试验为真空管太阳能集热器水平放置。试验结果表明:当集热器安装倾角为30°时,1 d内,水平放置的真空管太阳能集热器的瞬时集热效率呈现出先升高后降低的变化趋势,竖直放置的真空管太阳能集热器的瞬时集热效率呈现出先降低后升高的变化趋势;水平放置的真空管太阳能集热器的入射角修正系数随着入射角的增大而减小;当入射角由0°逐渐增大至45°时,竖直放置的真空管太阳能集热器的入射角修正系数呈现出先增大后减小的变化趋势;当水平放置的真空管太阳能集热器的入射角大于30°,竖直放置的真空管太阳能集热器的入射角大于15°时,将入射角修正系数引入瞬时集热效率拟合公式中,可以明显提高热性能评价结果的准确性。

In order to investigate the influence of tube arrangement moods thermal performance and incident angle modifier of evacuated tube solar collector,two sets of evacuated tube solar collectors were tested on outdoor conditions.The tubes in one collector are vertically arranged,and those in another collector are horizontally oriented.The results showed that when the tilt angle of the evacuated tube collector was 30°,the instantaneous efficiency of the horizontally arranged collector in one day increased first and then decreased,and the instantaneous efficiency of the vertical collector decreased first and then increased.The incident angle modifier of the transverse evacuated tube solar collector decreased as the incident angle increased.The incident angle modifier of the vertical evacuated tube solar collector increased with the increase of incident angle when the incident angle was less than 45°,and then decreased.It was found that the use of the incident angle modifier suggested in this work could significantly improve the thermal performance prediction of evacuated solar collectors when the incident angle of the transverse evacuated tube solar collector was greater than 30°and the incident angle of the vertical evacuated tube solar collector was greater than 15°.