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This work presents a design of 1000 MW S–CO 2 coal-fired power system, containing not only a new methodology of S–CO 2 power system modeling, but also the specific directions for engineering design. The coupling between computational fluid dynamic simulations at boiler scale and the mathematical modeling of the thermal cycle facilitates a high reliability of the comprehensive design. Our analysis helps identify key questions and then delivers specific directions for engineering design, especially for the pressure drop penalty in tail flue and thermal-hydraulic performance of cooling wall. The proposed flue split method coupled with parallel utilization method can not only effectively reduce the pressure drop penalty but also simplify the system heater configuration. Moreover, the thermal performance of S–CO 2 cooling wall is improved by using the flue gas recirculation and cooling wall arrangement optimization. The optimized position and proportion of flue gas extraction are further obtained. Comprehensively, the proposed design of S–CO 2 coal-fired power system enhances the system net efficiency up to 51.00%, with an efficient utilization of residual heat and cooling wall temperature below 700 °C. • A multiscale modelling platform is proposed for S–CO 2 coal-fired power system. • An improved system is obtained with system net efficiency up to 51.00% and cooling wall temperature all below 700 °C. • Flue split method and parallel utilization are developed for efficient recovery of tail flue heat. • Flue gas recirculation and cooling wall optimization are used to improve thermal safety of S–CO 2 cooling wall. [ABSTRACT FROM AUTHOR]

• A novel optimization algorithm called disturbance inspired equilibrium optimizer was developed. • New hybrid population initialization technique was proposed to generate high-quality initial population. • Novel update rules and adaptive position disturbance mechanism were proposed to improve exploitation and exploration. • Evaluation on representative mathematical benchmark functions and three real-world engineering problems. • Comparisons verified efficiency and superiority of the proposed algorithm. This work proposes a novel adaptive global optimization algorithm called Disturbance Inspired Equilibrium Optimizer. The purpose of this study is to enhance the exploitation ability of the newly developed Equilibrium Optimizer, and to address the issue of getting trapped in local minima. The proposed algorithm is benefited from the novel disturbance-based hybrid initialization strategy, the new form of time factor, and the new update rule of particle's position. In addition, a novel boundary check strategy and an adaptive global position disturbance mechanism are proposed and installed into our algorithm. Based on the disturbance-inspired modifications, the exploration and exploitation ability of the standard Equilibrium Optimizer are significantly improved. The performance of the proposed algorithm is evaluated using representative different benchmark functions, consisting of three well-known mathematical benchmark functions, six complex composite functions, and four challenge functions proposed on 2017 IEEE Congress on Evolutionary Computation. Also, the proposed algorithm is conducted to optimize three engineering designs to examine its applicability in constrained real-world problems. In all experiments, the developed algorithm is compared with six other state-of-the-art metaheuristics. Experimental results and the average rank of Friedman test show that our algorithm provides promising results in solving mathematical problems and constrained real-world engineering optimization problems. Therefore, the proposed algorithm is competitive compared to the other state-of-the-art metaheuristic algorithms and is an effective solution to real-world engineering problems. [ABSTRACT FROM AUTHOR]

• An integration system with adaptive modification module for 1000 MW S-CO 2 Brayton cycle and coal-fired boiler is developed. • The effects of typical layout parameters on thermal-hydraulic performance are obtained. • A layout with the highest thermal-hydraulic performance is proposed. • Accurate engineering design of S-CO 2 coal-fired power plants can be realized based on the integration system. An integration system for 1000 MW S-CO 2 connected-top-bottom power cycle with overlap utilization and coal-fired boiler is developed. The adaptive modification module is introduced to eliminate the non-convergence for S-CO 2 superheater thermal calculation in the system iteration. Thermal-hydraulic performance in terms of thermal performance, cycle efficiency, heater configurations, heater areas and final parameter evenness are discussed. Firstly, the strong constraint effects of inlet and outlet parameters on superheater thermal calculation convergence are demonstrated and the adaptive modification module is established. Secondly, based on the detailed thermal-hydraulic analysis, different layouts are compared to identify the flow path way and the heat absorption of S-CO 2 flow in different heating processes. The midpoint between the two peaks of heat flux is recommended as the start point for the cold fluid placement in cooling wall arrangement. Finally, a new layout is proposed to obtain the highest overall thermal-hydraulic performance, with a net power efficiency up to 47.57% and a total heater area of 316426.18 m2. The design sequences for S-CO 2 coal-fired boiler heaters are recommended as well. [ABSTRACT FROM AUTHOR]