The flat plate collector (FPC) has a low economic cost, while the parabolic trough collector (PTC) has a high heat collection temperature. To reduce costs, improve efficiency, and promote the use of solar energy, this study proposes a new two-stage solar collector that couples FPC and PTC. The main objective of this paper is to verify the performance of this two-stage solar collector when containing nanofluids. This collector drives the organic Rankine cycle (ORC) with four nanoparticles (Cu, CuO, TiO, and AlO) in the oil heat transfer fluid. The FPC outlet temperature in the two-stage solar collector is optimized, the exergy of ORC is analyzed, and the economics of the new system using nanofluid are calculated and compared with those of the new system without nanofluid. Results show that Cu-oil outperforms the other nanofluids in terms of heat transfer. At a rated output power of 5 kW, the new two-stage solar collector with 5 % Cu-oil can reduce economic costs by 6.8 % compared with a single PTC. Meanwhile, the ORC with a two-stage solar collector using 5 % Cu-oil reduces the economic costs by 5.7 % compared with the ORC equipped with PTC without nanofluid. The new system has a minimum payback period of 17.3 years, and increasing the output power of the ORC is beneficial for reducing the investment payback period of the system.

中文翻译：

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使用新型两级纳米流体太阳能集热器对有机朗肯循环进行热经济分析

平板集热器（FPC）经济成本低，而抛物槽式集热器（PTC）集热温度高。为了降低成本、提高效率并促进太阳能的使用，本研究提出了一种新型的将 FPC 和 PTC 耦合的两级太阳能集热器。本文的主要目的是验证这种两级太阳能集热器在含有纳米流体时的性能。该收集器利用油传热流体中的四种纳米粒子（Cu、CuO、TiO 和 Al2O）驱动有机朗肯循环 (ORC)。对两级太阳能集热器中的FPC出口温度进行了优化，分析了ORC的火用，计算了使用纳米流体的新系统的经济性，并与不使用纳米流体的新系统进行了比较。结果表明，铜油在传热方面优于其他纳米流体。在额定输出功率为5kW时，采用5%铜油的新型两级太阳能集热器与单个PTC相比可降低6.8%的经济成本。同时，使用5%铜油的两级太阳能集热器的ORC与配备不使用纳米流体的PTC的ORC相比，经济成本降低了5.7%。新系统的最小投资回收期为17.3年，增加ORC的输出功率有利于缩短系统的投资回收期。