中文摘要：

通过建立腔式吸热器热损失性能测试实验台,采用电加热的方法,分别在所有壁面加热和只有底面（开口对面）加热2种情况下,探讨倾角和热流密度等参数对一侧全开式圆柱形腔式吸热器热损失的影响,获得自然对流热损失的努塞尔特数Nuc和辐射热损失的努塞尔特数Nur分别与格拉晓夫数Gr、倾角φ、自然对流热损失的热流密度qc或辐射热损失的热流密度qr的实验关联式。结果表明,输入功率不变时,吸热器的自然对流热损失随着φ的增大而减小,导热损失和辐射热损失随φ的增大而增大,但增大的幅度不大;当qc一定时,Nuc随φ的增大而减小,而当qr一定时,φ对Nur的影响很小;并且2种加热情况下的热损失性能存在一定的差异,加热位置对辐射热损失的影响要比对自然对流热损失的影响小。

英文摘要：

An experimental investigation using electric heating method is carried out to explore the effect of tilt angle and heat flux on heat losses of a fully opened cylindrical cavity receiver.Two cases are examined,i.e.all walls of cavity heated and only the bottom wall（opposite wall of opening）heated.For both cases,the walls are heated at a constant heat flux.The empirical correlations of Nusselt numbers of natural convection and radiation heat losses versus the Grashof number,tilt angle and corresponding heat loss flux are proposed.The results show that,with constant input power,the natural convection heat loss of receiver decreases as the tilt angle increases while the conduction heat loss and the radiation heat loss increase slightly.When the heat flux of natural convection heat loss keeps constant,Nusselt number for determining the natural convection heat loss reduces with increasing tilt angle.However,when the heat flux of radiation heat loss remains constant,the tilt angle has very little effect on the Nusselt number for determining the radiation heat loss.Also,there is a certain difference of heat loss performance between two cases,and the wall heating location has a relatively samll influence on the radiation heat loss in comparison with on the natural convection heat loss.