Organic Rankine Cycle (ORC) is widely investigated for low-grade waste heat recovery, but its performance deteriorates under heat source with thermal power fluctuations. As the effects of fluctuating heat source on ORC system performance is less investigated, the operating rules of ORC systems under fluctuating heat source are not clear. In this study, the effects of fluctuating amplitude and period for fluctuating heat sources on the performance of a basic ORC system are studied in detail, considering the proposed indicators including safety and efficiency. Afterwards, the allowable fluctuation ranges of heat source are obtained based on requirements of safety and efficiency. Finally, the impact of the average temperature of fluctuating heat sources on the allowable fluctuation range is systematically investigated. The results indicate that the safety limitations and efficiency of the basic ORC system are generally negatively related to fluctuating amplitude and period, and the allowable fluctuation range is generally positively related to average temperature of heat source. To ensure the efficient operation of basic ORC, the allowable relative amplitude is 25–40 K under large fluctuating period while it is higher than 35 K with the fluctuating period smaller than 200 s. This study contributes to provide valuable reference for evaluating the performance of an existing ORC system under different fluctuating heat source conditions.

对有机朗肯循环（ORC）进行了低级废热回收的广泛研究，但是在热功率波动的情况下，其性能会下降。由于较少研究热源波动对ORC系统性能的影响，因此不清楚在热源波动下ORC系统的运行规则。在这项研究中，考虑到包括安全性和效率在内的拟议指标，详细研究了波动幅度和周期对热源的波动对基本ORC系统性能的影响。然后，根据安全性和效率的要求获得热源的允许波动范围。最后，系统地研究了波动热源平均温度对容许波动范围的影响。结果表明，基本ORC系统的安全限制和效率通常与幅度和周期的波动呈负相关，而允许的波动范围通常与热源的平均温度呈正相关。为了确保基本ORC的有效运行，在较大的波动周期内，允许的相对幅度为25–40 K，而在波动周期小于200 s时，则允许的相对幅度大于35K。这项研究为评估现有ORC系统在不同的波动热源条件下的性能提供了有价值的参考。为了确保基本ORC的有效运行，在较大的波动周期内，允许的相对幅度为25–40 K，而在波动周期小于200 s时，则允许的相对幅度大于35K。这项研究为评估现有ORC系统在不同的波动热源条件下的性能提供了有价值的参考。为了确保基本ORC的有效运行，在较大的波动周期内，允许的相对幅度为25–40 K，而在波动周期小于200 s时，则允许的相对幅度大于35K。这项研究为评估现有ORC系统在不同的波动热源条件下的性能提供了有价值的参考。