Chemical looping reactor superheater modelling and optimization
Crete, Mikhail (2026)
Kandidaatintyö
2026
School of Energy Systems, Energiatekniikka
Kaikki oikeudet pidätetään.
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi-fe20260629106766
https://urn.fi/URN:NBN:fi-fe20260629106766
Tiivistelmä
Chemical looping combustion with oxygen uncoupling (CLOU) is a novel combustion and carbon capture concept in which an oxygen carrier transfers oxygen between air and fuel reactors and releases gaseous oxygen under fuel reactor conditions. This thesis aims to develop a steady-state thermohydraulic model for a CLOU fuel reactor superheater with integrated feedwater desuperheating and optimize it with constrained optimization algorithm (CS3).
The superheater is represented as a staged crossflow heat exchanger divided into threedimensional control volumes. The model combines gas-side convection, participating-gas radiation, wall conduction, steam-side convection, pressure-loss calculation, material-temperature limits, fouling correction, and spray-water mixing. The evaluation framework is coupled with a modified CS3 constrained population search using epsilon-based feasibility ranking and mixed fidelity surrogate screening.
The reported numerical results focus on the first superheater stage. Across five optimization runs, the best strictly feasible designs converged to a narrow objective range and showed similar thermohydraulic behaviour: outlet steam temperature near the lower edge of the admissible band, gas velocity close to the target range, moderate tube-side velocity, compact heat-transfer area, and minimized spray-water flow. The results demonstrate the feasibility of the modelling and optimization framework, while full three-stage optimization and detailed validation are reserved future work.
The superheater is represented as a staged crossflow heat exchanger divided into threedimensional control volumes. The model combines gas-side convection, participating-gas radiation, wall conduction, steam-side convection, pressure-loss calculation, material-temperature limits, fouling correction, and spray-water mixing. The evaluation framework is coupled with a modified CS3 constrained population search using epsilon-based feasibility ranking and mixed fidelity surrogate screening.
The reported numerical results focus on the first superheater stage. Across five optimization runs, the best strictly feasible designs converged to a narrow objective range and showed similar thermohydraulic behaviour: outlet steam temperature near the lower edge of the admissible band, gas velocity close to the target range, moderate tube-side velocity, compact heat-transfer area, and minimized spray-water flow. The results demonstrate the feasibility of the modelling and optimization framework, while full three-stage optimization and detailed validation are reserved future work.