| Abstract: |
Industrial processes are responsible for a large fraction of global primary energy consumption and even larger portion of that is rejected to the environment as waste heat. Consequently, the design and optimization of Waste Heat Recovery (WHR) systems have emerged as one of the imperative strategies for energy efficiency improvement and reducing fossil-fuel reliance and greenhouse-gas emissions in energy intensive sectors like cement, iron and steel, glass, ceramics, chemical and food industries. This review provides an organized framework, synthesis, and meta-analysis of earlier works on the design and optimization of a waste heat recovery (WHR) system from fundamental thermodynamic studies to recent advances in multi-objective optimization, predictive control with data science, analysis based on advanced exergy costing, etc. The analyzed recovery technologies are due to their importance in the industry recuperators, regenerators, heat-pipe heat exchangers, economizers, waste heat boilers, Organic Rankine Cycle units, Kalina cycles thermoelectric generators and absorption chillers. The current paper reviews selection criteria, working-fluid screening, exergoeconomic indicators and process-integration tools including pinch analysis. Methods The Methods section outlines the systematic literature search comprising a screening protocol and meta-analytical approach for comparably integrating reported energy savings, exergy efficiencies, and payback periods. The critical review points out continuing deficiencies such as variable boundary considerations, concerns with transient operating conditions, insufficient experimental validation at industrial scale and sluggish market entry of low temperature recovery technologies. The study points out trends converging toward hybrid and cogeneration architectures, digitalization, and life-cycle-aware optimization. Conclusion The authors of the paper conclude that an integrated, multi-objective and data-driven design philosophy is key to realizing the full potential of waste heat recovery in modern sustainable industrial processes. |
