Exergy efficiency design for multi-stream plate-fin heat exchangers based on entropy generation assessment

The fundamental concepts of energy, entropy and exergy are progressively introduced for deepening. Furthermore, the state corresponding to the designated exergy is creatively defined as the referential assessment benchmark so as to asymptotically reckon the optimal rigorous operation decisions. Inspired by bionics design, the different types of lateral perforated fins and wavy fins are designed for various application scenarios. The temperature, T-Q diagram, entropy generation, dimensionless entropy generation, exergy loss and exergy efficiency within either stream or system hierarchy are observed to evaluate the adjustable design portfolio, for trade-off between benefits and costs. The proposed entropy generation assessment (EGA) is verified by physical experiment under different Reynolds number. The results prove that, the net cost of multi-stream plate-fin heat exchangers (MPFHE) is reduced from 20,813 $/kW to 19,072 $/kW after using EGA by -8.36%, while maintaining exergy efficiency. Therefore, EGA herein has important perspicacity for energy availability utilisation and operating economical assessment among heat exchange fields.y