Performance and cost assessment of Integrated Solar Combined Cycle Systems (ISCCSs) using CO2 as heat transfer fluid
Performance and cost assessment of Integrated Solar Combined Cycle Systems (ISCCSs) using CO2 as heat transfer fluid
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DOI：
10.1016/j.solener.2012.07.004
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发表时间：
2012-10
期刊：
影响因子：
6.7
通讯作者：
G. Cau;D. Cocco;Vittorio Tola
中科院分区：
文献类型：
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作者：
G. Cau;D. Cocco;Vittorio Tola
在本文中，报告了基于使用二氧化碳作为传热流体的抛物线槽的集成太阳能联合循环系统（ISCCS）的性能和成本评估。使用二氧化碳代替更传统的导热油作为传热流体可以提高传热流体的温度，从而提高太阳能转换效率。特别是，这里考虑的 ISCCS 发电厂是在额定功率约为 250MW 的三压再热联合循环发电厂的基础上开发的。考虑并比较了太阳能蒸汽发生器的两种不同解决方案。性能评估结果表明，CO2最高温度为550°C时，太阳能转换效率为23%至25%。当二氧化碳温度为 450°C 时，太阳能效率下降约 1.5-2.0%。使用仅包括蒸发部分而不包括预热、蒸发和过热部分的太阳能蒸汽发生器可以实现稍微更好的转换效率。然而，采用该解决方案后，ISCCS 电力输出中太阳能份额的最大值约为 10%。这里考虑的 ICCS 系统的太阳能转换效率略高于基于蒸汽循环的更传统的聚光太阳能发电 (CSP) 系统 (20-23%)，并且与更先进的直接蒸汽发电太阳能发电厂的预测转换效率 (22-27%) 非常相似。初步成本分析结果表明，由于安装了太阳能场，ISCCS发电厂的电能生产成本与天然气联合循环（NGCC）相比有所增加。特别是，由太阳能产生的电能的具体成本比由天然气产生的电能高得多（大约两倍）。
In this paper, a performance and cost assessment of Integrated Solar Combined Cycle Systems (ISCCSs) based on parabolic troughs using CO2as heat transfer fluid is reported on. The use of CO2instead of the more conventional thermal oil as heat transfer fluid allows an increase in the temperature of the heat transfer fluid and thus in solar energy conversion efficiency. In particular, the ISCCS plant considered here was developed on the basis of a triple-pressure, reheated combined cycle power plant rated about 250MW. Two different solutions for the solar steam generator are considered and compared. The results of the performance assessment show that the solar energy conversion efficiency ranges from 23% to 25% for a CO2maximum temperature of 550°C. For a CO2temperature of 450°C, solar efficiency decreases by about 1.5–2.0% points. The use of a solar steam generator including only the evaporation section instead of the preheating, evaporation and superheating sections allows the achievement of slightly better conversion efficiencies. However, the adoption of this solution leads to a maximum value of the solar share of around 10% on the ISCCS power output. The solar conversion efficiencies of the ISCCS systems considered here are slightly greater than those of the more conventional Concentrating Solar Power (CSP) systems based on steam cycles (20–23%) and are very similar to the predicted conversion efficiencies of the more advanced direct steam generation solar plants (22–27%). The results of a preliminary cost analysis show that due to the installation of the solar field, the electrical energy production cost for ISCCS power plants increases in comparison to the natural gas combined cycle (NGCC). In particular, the specific cost of electrical energy produced from solar energy is much greater (about two-fold) than that of electrical energy produced from natural gas.