Performance Analysis of a Novel Hybrid Ejector Refrigeration System Driven by Medium- to High-Temperature Industrial Waste Heat

The thermally driven ejector refrigeration system is generally used to recover industrial waste heat to improve the energy efficiency of industrial processes. However, for conventional single-stage ejector refrigeration systems (ERSs), the higher-pressure steam derived from high-temperature waste heat elevates the primary fluid pressure, resulting in significant pressure mismatch with the secondary fluid, which consequently leads to large irreversible losses and substantial degradation in system performance. To address this issue, a novel hybrid ejector refrigeration system (NHERS) is proposed and analyzed under design and off-design conditions using thermodynamics. The results indicate that under design conditions, compared to the conventional single-stage ejector refrigeration system, the proposed hybrid ejector refrigeration system can achieve increases of about 20.6% in the entrainment ratio, around 15.2% in the coefficient of performance (COP), and about 21.4% in exergetic efficiency. Analyzing its performance under off-design conditions to provide technical solutions for the flexible operation of the hybrid ejector refrigeration system proposed in this paper can broaden its application scenarios. Consequently, the proposed NHERS demonstrates remarkable superiority in energy conversion and transfer processes, showing certain application prospects in the field of medium- to high-temperature industrial waste heat recovery.