利用复合抛物面聚光器（CPC）的非跟踪聚光及脉动热管的高热流密度传热能力，提出了CPC脉动热管太阳能集热器。通过对CPC聚光比的合理设计及脉动热管的小管径，一方面保证脉动热管吸热段表面有足够的热流密度，使其工作在较低热阻状态；另一方面，在4倍聚光比下，整个集热器的厚度与平板集热器相当。论文建立了CPC脉动热管太阳能集热器的三维漏热数值模型，并与实验结果进行了对比验证。然后，分析了太阳辐射强度、风速、材料厚度（玻璃和隔热板）以及倾角等因素对新型集热器热性能的影响。结果表明，CPC脉动热管太阳能集热器的理论集热效率可达74.5%。太阳辐射强度和环境风速是集热器漏热的主要影响因素，而增加保温板和玻璃盖板的厚度对集热器的集热效率影响不大。其中，太阳辐射强度影响了脉动热管吸热表面温度，从而影响了空气夹层的自然对流，进一步影响了通过空气夹层的对外漏热。而环境风速一方面增加了玻璃盖板表面对流换热强度，同时也减弱了空气夹层的自然对流强度。当集热器倾角为45°、太阳辐射强度为1000 W/m2时，集热性能最好。论文对小尺度下太阳能聚光集热提供了参考。
XU Rongji
,
CHEN Jingyan
,
ZHANG Xiaohui
,
WANG Ruixiang
,
XU Shuhui
. Heat Leakage Numerical Investigation of a Compound Parabolic Concentrator- Pulsating Heat Pipe Solar Collector[J]. 热科学学报, 2022
, 31(5)
: 1318
-1326
.
DOI: 10.1007/s11630-020-1293-3
As a new type of equipment for solar medium temperature utilization, the compound parabolic concentrator-pulsating heat pipe solar collector (CPC-PHPSC) uses pulsating heat pipe (PHP) as an endotherm, which can realize efficient energy conversion. The design of proper concentration ratio of compound parabolic concentrator (CPC) ensures that the incident sunlight can be concentrated on the evaporator section surface of PHP without solar tracking system. The objective of the present work is to study the influence of solar radiation intensity, air speed, material thickness (glass and insulation board) and tilt angle on the thermal performance of the new collector, which is difficult to control in the experiment. The heat leakage process and characteristics of the CPC-PHPSC were numerically studied by establishing a 3D numerical model of the collector unit. The results show that the theoretical collector efficiency of CPC-PHPSC reaches 74.5%, which is consistent with the experimental results. During operation, the heat collection performance is the best when the tilt angle is 45° and the solar radiation intensity is 1000 W/m2, while the excessive air speed will increase the convective heat loss. Increasing the thickness of insulation board and glass has little effect on the collector efficiency.
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