Authors: C. du Sart, P. Rousseau
Year: 2026
Industry: SCO2
Keywords: Use FSE, Dynamic, Two-phase
ABSTRACT
Despite increasing interest in supercritical carbon dioxide (sCO2) cycles in place of Rankine cycles for power generation, especially for concentrated solar power (CSP) applications, there are limited studies on the dynamic performance and control of utility-scale air-cooled heat exchangers (ACHEs) for sCO2-CSP plants. In this work, a combined fan on-off and bypass control system is proposed and demonstrated for an ACHE system of a 50 MWe sCO2 CSP plant. At off-design conditions, the control system prevents the formation of undesirable two-phase flow within the finned-tube bundles and ensures that the supercritical state and design temperature of the fluid are maintained at the ACHE exit, where it enters a compressor. The demonstration is performed using the commercial code Flownex and includes a stress test of the performance of the ACHE system during changing ambient conditions. The results show that the proposed control system, which leverages a classic proportional integral (PI) controller, can effectively be used for the control of sCO2 ACHEs.