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Abstract
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Advanced exergy analysis, alongside energy and conventional exergy methods, is critical for identifying the true potential of energy conversion systems. This study pioneers the application of advanced exergy analysis to a high-temperature Kalina cycle for the first time, for waste heat recovery from turbocharged diesel engine exhaust gases and coolant water, offering a comprehensive perspective on energy losses and optimization opportunities. The results highlight that over 82 % of the system's exergy destruction is endogenous, with approximately 47 % being avoidable through technological improvements. Moreover, nearly 45 % of total exergy destruction can be reduced, demonstrating substantial potential for efficiency enhancement. Notably, all cycle components (except recuperator 1) exhibit higher endogenous than exogenous exergy destruction, indicating that internal irreversibilities are the dominant cause of exergy loss, while inter-component interactions are less significant. Minimizing these irreversibilities is therefore essential for performance improvement. This work introduces a novel improvement strategy prioritizing avoidable endogenous exergy destruction. Unlike conventional exergy analysis, which ranks the evaporator as the top improvement target, the proposed method identifies the turbine as the primary focus, followed by the evaporator, recuperator 2, condenser 1, condenser 2, pump 2, and preheater. By presenting a groundbreaking advanced exergy analysis for this high-temperature Kalina cycle application, the study provides innovative insights into optimizing heat recovery systems and lays the foundation for future designs.
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