Modeling and Control of a Supercritical CO2 Water Cooler in an Indirect-Fired 10MWe Recompression Brayton Cycle Near Critical Conditions

Abstract A one-dimensional design and dynamic model of a microtube heat exchanger is presented for cooling supercritical CO2 to near critical conditions (35°C and ∼90 bar) with water. A control strategy is designed and implemented to achieve a desired hot-side CO2 outlet temperature, while the cooling-water exit temperature is monitored (ideally kept below 50°C). The control responses during drastic process changes at the boundaries such as sCO2 inlet flow/pressure and cooling water inlet temperature are presented.