A research team led by Prof. GUO Bin from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences has designed and optimized an organic Rankine cycle (ORC) system specifically for recovering low-grade waste heat from the steady-state Chinese Fusion Engineering Testing Reactor (CFETR) based on organic fluid R245fa, achieving enhanced thermal efficiency and reduced heat loss. 

Their findings were recently published in Energy.

CFETR, a steady-state magnetic fusion reactor, is a crucial step toward realizing commercial fusion energy. However, managing the large amount of low-grade waste heat produced by components such as the divertor and blanket remains a key challenge. 

In this study, to solve the thermodynamic and heat integration issues, the researchers developed advanced simulation models using Engineering Equation Solver for cycle analysis and MATLAB-based LAMP modeling for dynamic system configuration. These tools enabled a comprehensive investigation and optimization of the ORC configuration, leading to significantly improved thermal performance. 

The researchers addressed the challenge by designing and optimizing a thermal cycle that efficiently converts this residual heat into useful electricity using an ORC system. They demonstrated how this approach improves thermal efficiency and supports the sustainable operation of future fusion power plants. 

The innovative design of ORC for waste heat recovery not only demonstrates how low-grade waste heat can be effectively utilized in future fusion reactors but also provides a model framework that can be adapted to other high-temperature energy systems. 

"Our proposed cycle not only improves the overall energy utilization of CFETR, but also demonstrates a pathway for integrating low-grade heat into power generation," said Prof. GUO Bin.

This innovation provides a new route to tap into waste heat resources and contributes to the broader goal of developing clean, efficient fusion energy systems.

Flow chart for ORC design (Image by Muhammad Salman Khan)