摘要
为了提高聚光光伏系统的能量利用效率,本文提出了一种新型的聚光光伏/光热混合发电系统.该系统主要由带有蒸发冷却装置的聚光光伏模块、光热接收器和有机朗肯循环组成.液体有机工质在冷却聚光光伏模块时吸热蒸发,而后流经外围低聚光光热接收器时加热成为过热蒸汽,最终经由有机朗肯循环发电.针对该混合发电系统,本文提出了稳态模型,并进行了系统能量分析.结果表明利用聚光光伏模块外围的低聚光能量可以有效产生较高温度的过热蒸汽.当聚光比为500倍时,该系统可以将整体光电转换效率从传统的聚光光伏电池的28.4%显著提高到44%.因此,该混合发电系统为太阳能的更高效率发电提供了新的发展方向.
This study presents a novel solar concentrating photovoltaic/concentrating solar power （CPV/CSP） hybrid system, which mainly contains CPV modules with an evaporative cooling subsystem, a thermal receiver and an organic Rankine cycle （ORC）. The cooling fluid is boiled when cooling the CPV modules, and superheated vapor that is effective for power generation with an ORC is generated after absorbing low-concentration solar radiation in the thermal receiver. A steady-state physical model is developed to carry out energy analysis of the hybrid sys- tem. The results show that when saturated vapor is fed into the thermal receiver, the peripheral low-concentration solar radiation that is discarded in conventional CPV or CPV/ thermal systems is effective to get a high-temperature superheated vapor （e.g., above 120 ℃）. The overall solar- to-electricity efficiency can be increased from 28.4 % for the conventional CPV system to 44 % for the hybrid sys- tem with 500 suns. Even though the overall efficiency decreases from 44.0 % to 36.8 % when the concentration ratio increases from 500 to 2,000 suns, there is still a considerable efficiency improvement compared with the conventional CPV systems. The results indicate that the proposed hybrid system provides a viable solution for solar power generation with high efficiencies.
基金
supported by the National Natural Science Foundation of China(51106149 and 51406051)
the Fundamental Research Funds for the Central Universities
the Foundation of Key Laboratory of Thermo-Fluid Science and Engineering(Xi’an Jiaotong University),Ministry of Education,Xi’an710049,China
