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Dynamic Behavior Analysis of Complex-Configuration Organic Rankine Cycle Systems Using a Multi-Time-Scale Dynamic
1School of Marine Engineering Equipment, Zhejiang Ocean University, Zhoushan 316022, China.
Entropy (Basel, Switzerland)
|November 26, 2025
Summary
This study introduces a multi-time-scale modeling framework for complex Organic Rankine Cycle (ORC) systems. The method efficiently simulates ORC dynamics, improving control strategy development.
Area of Science:
- Thermodynamics
- Energy Systems Engineering
- Computational Modeling
Background:
- Complex Organic Rankine Cycle (ORC) systems present significant computational challenges for dynamic analysis due to strong multi-physics coupling.
- Accurate dynamic modeling is crucial for optimizing performance and developing advanced control strategies in ORC applications.
Purpose of the Study:
- To develop a computationally efficient and accurate multi-time-scale modeling framework for complex ORC systems.
- To reduce the simulation burden associated with dynamic analysis of ORC systems with intricate configurations.
Main Methods:
- A multi-time-scale modeling framework was proposed, partitioning the ORC system into second-, decisecond-, and hybrid-scale subsystems.
- Dynamic models were developed for key ORC components including heat exchangers, expanders, pumps, generators, and converters.
- The framework was validated using operational data from a basic ORC system and subsequently applied to dual-loop and multi-heat-source ORC configurations.
Main Results:
- The proposed multi-time-scale framework achieved a mean absolute error of 2.12% on a basic ORC system, demonstrating high accuracy.
- Application to a series dual-loop ORC showed enhanced disturbance rejection capabilities against fluctuations in heat sources and sinks.
- Analysis of a multi-heat-source ORC revealed that system dynamics are primarily influenced by the second heat source.
Conclusions:
- The multi-time-scale modeling framework offers an efficient and accurate approach for simulating complex ORC architectures.
- This framework provides a solid foundation for the development and testing of advanced control strategies for ORC systems.
- The study highlights the benefits of specific ORC configurations, such as dual-loop systems, for improved operational stability.
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