圆柱吸热体真空管集热器管中心距与能量收益关系的研究

在实验测定吸热板表面相对太阳辐照强度和涂层太阳吸收率的基础上，分析研究了圆柱形吸热体具有圆形和半圆形吸收涂层的真空管集热器在不同管中心距下的能量收益因子随光线入射角变化的规律，依据晴天辐射模型，对北半球不同纬度和倾角、朝南放置的上述两种真空管的日年能量收益，以及由上述两种真空管组成的太阳能集热器中心距与能量收益的关系进行了分析研究，给出了两种真空管日、年能量收益和两种集热器不同管中心距在各纬度和倾角下集热器日能量收益及其年变化规律。结果表明：在无遮挡时，圆形吸收涂层管比半圆形吸收涂层管年能量收益高9％。当圆形吸收涂层管中心间距等于2倍管径、半圆形吸收涂层管中心间距等于1．3倍管径时，可得到管无遮挡时年能量收益的95％。

A Study on the Relation Between Absorbed Energy and Center-to-Center Distance of Evacuated Tubes in Integral-Collector-Storage Solar Water Heater

Based on measuring data of solar irradiance ratio on absorbers with cylindric shape in evacuated collector tube(ETC) as well as that solar absorbtivity changing with incident angle on the coating,this paper has analyzed and investigated regular patterns of absorbed energy factor changing with incident angle at different center-to-center distances of ICSET with full-circular and semi-circular selective coating shape absorbers.According to the Clear-Day Model,daily and annual absorbed energy for different center-to-center distance of ICSET with full and semi-circular coating southward cylindrical absorbers at different northern latitudes and various inclined angles have been calculated and compared.The results showed that the annual absorbed energy of ICSET with full circular coating absorber is 9% higher than that with semi-circular coating absorber in out of sunshade between tubes and when the center-to-center distance of ICSET foul and semi-circular coating absorbers were 2 and 1.3 times the outer diameter of tube,the annul absorbed energy of two shape coating absorber is 95% as high as that out of sunshade.