Advanced nuclear technologies are crucial for the future. They drive decarbonization and support renewable energy integration. They also enable efficient hydrogen production, which is predicted to provide a clean and reliable energy source for future generations. Small modular reactors and advanced modular reactors operate at higher temperatures than traditional reactors, so innovative cooling solutions for advanced nuclear technologies are vital.
In this article, we explore how fluid topology optimization can revolutionize the design of high-temperature heat exchangers.
Case study: Designing a fluid topology-optimized heat exchanger
Figure 1: The ToffeeX cloud-based fluid topology optimization platform. Processing an optimization job to minimize pressure loss and volume temperature.
The project described in the whitepaper used fluid topology optimization (a key feature of the ToffeeX platform) to design heat exchangers for hydrogen cogeneration from high-temperature gas reactors.
The ToffeeX generative design software facilitated the creation of two distinct heat exchanger designs: cross-flow and counter-flow. High-fidelity conjugate heat transfer analysis estimated performance, incorporating fluid flow and heat transfer through the heat exchanger’s solid parts.
The simulations used helium/helium as working fluids and high-temperature nickel alloy for the heat exchanger material. The simulations demonstrated that heat exchangers designed using fluid topology optimization outperformed traditional designs. They achieved up to 8.5% increased heat transfer with only a 4% rise in pressure losses.
The application of fluid topology optimization
We applied fluid topology optimization and generative design to design a printed circuit heat exchanger (PCHX) capable of handling high-temperature and high-pressure gas flows such as carbon dioxide or helium. Engineers construct PCHXs with hot and cold media on opposite sides of diffusion-bonded plates, optimizing for specific heat transfer and pressure loss requirements.
The ToffeeX platform facilitated the optimization of these layers by processing design domains and fluid boundary conditions (flow rates, pressures, and temperatures). This process enabled quick iterations through designs, generating counter-flow and cross-flow configurations in a matter of hours.
Validation of optimized heat exchanger performance
We conducted high-fidelity conjugate heat transfer (CHT) simulations to validate the optimized heat exchanger designs. These simulations couple computational fluid dynamics (CFD) with heat conduction simulations to model fluid flow and heat transfer within the solid parts of the heat exchanger. This method minimizes assumptions and maximizes simulation accuracy, providing a robust performance prediction.
Figure 3: Comparison between the illustrative diagrams of the temperature and velocity streamlines in a conventional counter-flow PCHX design and a fluid-topology optimized counter-flow heat exchanger design.
The fluid topology-optimized design and conventional PCHX designs were analyzed under laminar and turbulent flow conditions, using helium as the working fluid and an Inconel alloy for the heat exchanger. Consequently, the simulations revealed that the fluid topology-optimized design PCHX offered a 3% higher Nusselt number at low Reynolds numbers and an 8.5% higher Nusselt number at high Reynolds numbers compared to conventional designs. These gains were achieved with only a 4% increase in the Fanning friction factor, indicating superior heat transfer efficiency with manageable pressure losses.
This project demonstrated that fluid topology optimization can effectively design high-performance printed circuit heat exchangers for such applications. Moreover, these designs succeed in both laminar and turbulent conditions and are manufacturable using traditional techniques.
Conclusion: advancing heat management in nuclear technologies
The exploration of fluid topology optimization shows its transformative potential in cooling solutions for advanced nuclear technologies. These designs enhance heat transfer efficiency while maintaining manageable pressure losses, paving the way for efficient and sustainable nuclear reactors.
This highlights how ToffeeX’s generative design software outperforms traditional models. It showcases increased heat transfer with minimal pressure loss increases. These advancements are crucial for high-temperature demands in small modular reactors (SMRs) and advanced modular reactors (AMRs). This supports broader applications like hydrogen cogeneration.
Fluid topology optimization’s success in cooling solutions for advanced nuclear technologies underscores its role in future-proofing heat management. This approach addresses higher operating temperatures and aligns with global decarbonization efforts, enhancing nuclear energy’s role in sustainable development.
By leveraging technologies like ToffeeX, the nuclear industry can achieve significant strides forward. This ensures advanced nuclear technologies continue to play a pivotal role in clean energy.
