A Review of Evaluation, Optimization and Synthesis of Energy Systems: Methodology and Application to Thermal Power Plants

Abstract

To reach optimal/better conceptual designs of energy systems, key design variables should be optimized/adapted with system layouts, which may contribute significantly to system improvement. Layout improvement can be proposed by combining system analysis with engineers’ judgments; however, optimal flowsheet synthesis is not trivial and can be best addressed by mathematical programming. In addition, multiple objectives are always involved for decision makers. Therefore, this paper reviews progressively the methodologies of system evaluation, optimization, and synthesis for the conceptual design of energy systems, and highlights the applications to thermal power plants, which are still supposed to play a significant role in the near future. For system evaluation, both conventional and advanced exergy-based analysis methods, including (advanced) exergoeconomics are deeply discussed and compared methodologically with recent developments. The advanced analysis is highlighted for further revealing the source, avoidability, and interactions among exergy destruction or cost of different components. For optimization and layout synthesis, after a general description of typical optimization problems and the solving methods, the superstructure-based and -free concepts are introduced and intensively compared by emphasizing the automatic generation and identification of structural alternatives. The theoretical basis of the most commonly-used multi-objective techniques and recent developments are given to offer high-quality Pareto front for decision makers, with an emphasis on evolutionary algorithms. Finally, the selected analysis and synthesis methods for layout improvement are compared and future perspectives are concluded with the emphasis on considering additional constraints for real-world designs and retrofits, possible methodology development for evaluation and synthesis, and the importance of good modeling practice.

Evaluation of Large-Scale Production of Chitosan Microbeads Modified with Nanoparticles Based on Exergy Analysis

“…For the simulation of large-scale production processes of chitosan microbeads was used the industrial process software Aspen Plus, the chemical species required for the simulations were taken from the software database. For those compounds which are not available in the software database, molecules were created using the Aspen Property Estimator based on the properties reported for these species in the literature [18]. It was necessary to create components such as titanium isopropoxide and chitosan during the development of this work.…”

Optimum Choice of Energy System Configuration and Storages for a Proper Match between Energy Conversion and Demands

“…Wang et al [2] review existing methodologies for the three general topics of: (1) System evaluation, (2) optimization of the system design, and (3) optimization of the system configuration (synthesis). The focus is on thermal power plants, which are still supposed to play a significant role in the near future.…”

“…In this step, the definition of the optimum configuration of each single plant is crucial and involves a proper match among its components according to the purpose of the overall energy system. (2) The definition of the final system configuration, which requires a proper match between sources, plants, and users. Storage capacities are often necessary to find this match, to store fuels or product energy streams.…”

A comprehensive thermodynamic analysis of load‐flexible CHP plants using district heating network

“…Combined heat and power (CHP) generation has been widely adopted because of the reduction of energy losses and environmental benefits . In the countries treating coal as the main energy source, such as China and Germany, coal‐based CHP plants have been highly developed along with the sharp increase of heat and power demand . In recent years, with the rapid development of renewable energy sources, CHP plants are encouraged to enhance operational flexibility to reduce the renewables curtailment, including extending the load range and reducing the start‐up time .…”

“…1,2 In the countries treating coal as the main energy source, such as China [3][4][5] and Germany, 6 coal-based CHP plants have been highly developed along with the sharp increase of heat and power demand. 7,8 In recent years, with the rapid development of renewable energy sources, CHP plants are encouraged to enhance operational flexibility to reduce the renewables curtailment, including extending the load range [9][10][11] and reducing the start-up time. 12 Moreover, the better quick-response ability is also required to follow the changing electric power demand continuously, 13,14 because the rapid expansion of intermittent renewable energy 15 makes the balance between electricity production and consumption in the grid hard to keep.…”