Numerical investigation of superheating secondary flow on performance of steam ejector by considering non-equilibrium condensation in renewable refrigeration cycle

Abstract The escalating global concern over climate change and the urgent need for sustainable solutions have propelled renewable energy technologies into the spotlight. Among these, renewable refrigeration cycles have emerged as a promising research area, offering environmentally friendly alternatives to traditional refrigeration systems. Ejector refrigeration cycles (ERCs), particularly those employing water as the working fluid, have garnered significant attention due to their inherent advantages. To further optimize the performance of ERCs, a comprehensive understanding of the underlying flow phenomena and their impact on system efficiency is crucial. The primary objective is to explore the impact of secondary flow superheating on the ejector’s performance and flow characteristics. A parametric study is conducted by varying the secondary flow superheating degree from 0 K to 30 K while maintaining constant secondary flow pressures of 1,200 Pa and 1,800 Pa. The results revealed that while the overall flow pattern remained relatively unaffected by the increase in superheating, the ejector’s performance and exergy destruction were significantly impacted. A noteworthy observation is the inverse relationship between secondary flow superheating and entrainment ratio. As the superheating degree increases, the entrainment ratio exhibits a corresponding decrease. For instance, a 30-degree increase in superheat resulted in a 2.8 % and 3.9 % reduction in entrainment ratio at 1,200 Pa and 1,800 Pa, respectively.