Integration, Control, and Testing of a High-Temperature Particle-to-sCO2 Heat Exchanger

The development of a particle-to-sCO(2) heat exchanger is a critical step toward the realization of a particle-based CSP system. In this paper, the work on the integration and future testing of a 100 kWi moving packed-bed heat exchanger prototype is reported. The device will be integrated with the falling particle receiver test loop at Sandia National Laboratories and integrated with a high-pressure sCO(2) flow loop for heat rejection. A testing campaign is described including low-temperature (< 700 degrees C) ground-based testing where the particles will be heated using electrical energy prior to lifting the heat exchanger to the top of the tower for on-sun testing targeting sCO(2) temperature > 700 degrees C. Furthermore, the development of an sCO(2) mixing Tee is described, which allows for the sCO(2) flow loop to be operated at temperatures over 700 degrees C without requiring high-temperature heat rejection or significant amounts of high-nickel piping.