Comparative analysis on evaporator design and heat pump system performance under different zeotropic mixture flow boiling correlations: Waste heat recovery for tobacco factory air compressor

With rising concerns about energy shortages and pollution, an efficient use of industrial waste heat is now a key research focus. This paper studied the effects of zeotropic mixture heat transfer correlations of flow boiling on plate evaporator design and performance parameters of the heat pump system for waste heat recovery for tobacco factory air compressors. At the optimal design condition, the Huang et al. [“Experimental analysis of high temperature flow boiling of zeotropic mixture R134a/R245fa in a plate heat exchanger,” Appl. Therm. Eng. 220, 119652 (2023)] correlation predicts the longest plate length at 2.34 m and the highest cost, while the Lee et al. [“Evaporation heat transfer and pressure drop characteristics of R1234ze(E)/R32 as a function of composition ratio in a brazed plate heat exchanger,” Int. J. Heat Mass Transfer 140, 216–226 (2019)] correlation predicts the shortest at 0.79 m. Under off-design conditions, higher temperatures and flow rates increase superheat degrees and reduce heat exchange rates and efficiencies. The Huang et al. correlation achieves superior performance with a coefficient of performance (COP) of 3.83, exergy efficiency of 47.90%, payback time of 5.38 yrs, and heat supply cost of 43.5 €/MW h at a heat source temperature of 56 °C. Conversely, the Lee et al. correlation predicts less favorable outcomes, including a COP of 3.51 and a payback time of 5.6 yrs. The findings emphasize the importance of correlation selection for optimizing heat pump design, thermodynamic performance, and economic viability.