Session: 30-07 Heat Pumps

Submission Number: 176987

Multiobjective Optimization of Supercritical CO2 Cycles Coupled With Green Ammonia Production Processes Based on Thermodynamic and Artificial Intelligence Models 

Abstract: Green ammonia(NH₃) co-firing can substantially curtail carbon emissions from coal-fired power plants and thus constitutes a viable pathway for power sector decarbonization; however, green NH₃ synthesis is energetically demanding and produces considerable thermal waste. To enhance system energy utilization and reduce reliance on external heat inputs, this study proposed the deployment of a supercritical CO₂ (sCO₂) power cycle as a bottoming cycle to recuperate waste heat from green NH₃ production. The proposed coupling leverages the heat of compression inherent to the sCO₂ compressor to heat and vaporize liquid NH₃, enabling direct injection of NH₃ gas into the boiler. This arrangement both obviated the auxiliary thermal supply normally required for NH₃ vaporization and, by reducing compressor inlet temperature and improving thermodynamic coupling, augmented the bottoming cycle’s net power output and the overall system thermodynamic efficiency. To mitigate uncertainty in the admissible bounds of decision variables, a multilayer perceptron (MLP) surrogate of the thermodynamic system model, trained on simulation data to approximate the input–output mapping, is embedded within NSGA-III as a fast evaluator to accelerate multi-objective optimization. Case-study analyses demonstrated that the proposed coupling significantly enhanced thermal efficiency, reduced external heat demand, and improved system thermodynamic performance, thereby providing a robust reference for the integrated design of sCO₂ cycles and green NH₃ production.

Keywords: Supercritical CO₂ power cycle; Green ammonia; Waste heat recovery; Energy efficiency improvement；Multi-objective optimization

Presenting Author: Kang Zhou Southeast University

Presenting Author Biography: Kang Zhou is a second-year Ph.D. candidate in Power Engineering at Southeast University. His research focuses on supercritical CO₂ power cycles, waste-heat recovery, and thermodynamic optimization.

Authors:

Kang Zhou Southeast University
Yue Cao Southeast University
Jianxin Zhou Southeast University
Fengqi Si Southeast University