Response behaviors of CO2 transcritical Rankine cycle based parabolic trough solar power plant to cloud disturbance

• Published in: Applied thermal engineering Vol. 189; p. 116722
• Main Authors: Rao, Zhenghua, Peng, Cunyue, Wang, Yaqiong, Wang, Yitao, Liu, Gang, Liao, Shengming
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 05.05.2021; Elsevier BV
• Subjects: Carbon dioxide; Cloud cover; Cloud disturbance; Clouds; CO2 transcritical Rankine cycle; Dynamic simulation; Heat conductivity; Heat transfer; Parabolic trough concentrating solar power; Rankine cycle; Recovery time; Solar energy; Stability; Thermal cycling; Thickness; Parabolic trough concentrating solar power; Dynamic simulation; Cloud disturbance; CO2 transcritical Rankine cycle
• ISSN: 1359-4311; 1873-5606
• DOI: 10.1016/j.applthermaleng.2021.116722

•Dynamic behaviors of solar powered transcritical CO2 Rankine cycle are simulated.•Cloud thickness affects variation range and cover duration affects recovery time.•Regenerative system has a higher efficiency but slower response to cloud disturbance.•Sun tracking mode affects the effective operating duration and average efficiency.•Decrease in system efficiency due to moving cloud is smaller than stationary case. The CO2 transcritical Rankine cycle (CO2-TRC) has a great potential for the application in concentrating solar power (CSP) system due to the advantages of using low- and medium- temperature sources and compact structures. However, the cloud passages always lead to the suddenly varied heat input to the system, while understanding the system’s response to the cloud disturbance may enable the operational stability which is viable for driving the advanced CO2-TRC system. In this study, a dynamic thermodynamics model is developed to simulate the response behaviors of the simple and regenerative CO2-TRC based trough CSP systems under various cloud disturbances. The results show that by examining the system’s performances, the cloud thickness mainly affects the variation range, while the cloud cover duration mainly affects recovery time. At the same cloud thickness, the recovery time for the regenerative system could be about three times longer than that for the simple system. Subject to the cloud with same cover duration, the simple system tends to reach the stable state in the shorter time. As the collector is shaded by a moving cloud, the system’s recovery time is almost same but the system efficiency has the smaller decrease as compared to the stationary cloud coverage with the same duration. These results allow determining the optimal design and operating scheme of the CO2-TRC based CSP systems to increase the output power and operating stability.