The first experimental tests of novel bivalent hybrid ejector-compressor refrigeration system

A sustainable approach to refrigeration involves hybrid systems combining heat driven ejector and electrically driven compressor technologies to leverage low-grade heat effectively. However, practical implementation of such systems is limited. This study presents the experimental validation of a 23 kW bivalent hybrid vapor ejector-compressor refrigeration system designed to produce chilled water at 6/12 °C for air-conditioning applications. The system can operate as ejector-driven and compressor-driven based on operational conditions, addressing the ejector limitations under high condensation pressures. Experimental results demonstrate the system capability to maintain a cooling output, achieving a coefficient of performance (COP) of 0.30 in an ejector mode and average 4.70 in a compressor mode. The mode-switching, i.e. bivalent point, corresponds to a condensation temperature of approximately 25 °C. Energy analysis reveals significant potential savings during ejector operation, highlighting its efficiency under favorable conditions. This work bridges the gap between theoretical modeling and practical application by experimentally validating the hybrid system performance. Additionally, a simple economic analysis underscores the viability of the system, estimating annual energy consumption at 42,836 kWh for continuous operation. These findings provide valuable insights for the design and deployment of hybrid refrigeration systems aimed at reducing environmental impact while maintaining operational flexibility.