A novel organic Rankine cycle system with coupled dual vortex tubes: A comprehensive 5E analysis, life cycle assessment, and multi-objective optimization

To enhance the comprehensive utilization of industrial waste heat and residual pressure resources, this paper proposes a novel organic Rankine cycle (ORC) system coupled with dual vortex tubes and a pneumatic booster pump (DVT-ORC). A comprehensive evaluation model covering energy, exergy, exergoeconomic, economic, and environmental aspects was established, and combined with life cycle assessment (LCA) and multi-objective optimization, the system performance under design conditions and the influence mechanisms of key parameters were analyzed. The results show that under the set conditions, the system achieves an exergy efficiency of 52.84%, a net power output of 175.50 kW, a payback period of only 3.58 years, a levelized cost of electricity as low as 0.030 $/(kW·h), and an annual CO2 emission reduction of 3.71 × 106 kg, outperforming five comparative ORC systems in overall performance. Parameter analysis indicates that heat source pressure and vortex-tube cold flow ratios significantly affect system efficiency and economic performance. Multi-objective optimization further yields optimal operating conditions that balance exergy efficiency, payback period, and emission reduction. The study confirms that the DVT-ORC system offers notable advantages in improving the comprehensive conversion efficiency of low-grade energy, reducing costs, and enhancing environmental benefits, providing an effective technical pathway for the synergistic recovery of industrial waste heat and pressure.