In the present study, a novel combined power cycle for solar power tower (SPT) system consisting of helium Brayton cycle (HBC) and transcritical CO₂ (TCO₂) for waste heat recovery is being studied for carbon-free generation. The performance of the proposed SPT based combined cycle (SPT-HBC-TCO₂ cycle) is compared with SPT based basic cycle (SPT-HBC) based on exergoeconomic and thermodynamic analyses. It is concluded that the SPT-based combined cycle (SPT-HBC-TCO₂ cycle) produces a thermal efficiency of 32.39% and exergy efficiency of 34.68% with an electricity cost of 1.613 UScent kWh⁻¹. The exergy and thermal efficiency of the SPT-based combined cycle are enhanced by 13.18% and 13.21% respectively, while electricity cost is reduced by around 2% as compared to the SPT-based basic cycle (SPT-HBC) configuration at base conditions. A notable finding is that, despite the additional expenditures related to the bottoming cycle, the cost of electricity is lesser for the proposed combined cycle. Additionally, a comparison with the related prior published research exhibits that the performance of the current novel system is superior to that of the systems based on steam rankine cycle and supercritical CO₂ cycles.

中文翻译：

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基于太阳能发电塔的新型组合氦布雷顿循环-跨临界二氧化碳循环的无碳发电的能量经济和热力学分析

在本研究中，正在研究一种新型太阳能塔式联合动力循环（SPT）系统，该系统由氦布雷顿循环（HBC）和用于废热回收的跨临界CO ₂ (TCO _{2 )组成，以实现无碳发电。基于能量经济和热力学分析，将所提出的基于 SPT 的联合循环（SPT-HBC-TCO 2}循环）的性能与基于 SPT 的基本循环（SPT-HBC）进行比较。结论是，基于SPT的联合循环（SPT-HBC-TCO ₂循环）的热效率为32.39%，火用效率为34.68%，电费为1.613 UScent kWh ^-1。基础工况下，与基于SPT的基本循环（SPT-HBC）配置相比，基于SPT的联合循环的火用效率和热效率分别提高了13.18%和13.21%，而电费降低了约2%。一个值得注意的发现是，尽管与底部循环相关的额外支出，但拟议的联合循环的电力成本较低。此外，与先前发表的相关研究的比较表明，当前新颖系统的性能优于基于蒸汽朗肯循环和超临界CO ₂循环的系统。