Experimental study on ejector design and performance of its refrigeration system

• The ejector-integrated refrigeration system was developed and analyzed. • Based on 1-D thermodynamic model, the ejector optimal design was completed. • The system performance improvement with ejector was verified through the experiment. • The system showed nearly 20.8% COP improvement and 5% higher refrigeration capacity. Propelled by low-grade energy, the ejector-integrated refrigeration system offers advantages such as an uncomplicated structure, stable operation, little maintenance requirements, and low operating costs, making them a recent research hotspot. Performance severely degrades under off-design operating conditions, limiting their wider application in the refrigeration field. To enhance the performance of the ejector-integrated refrigeration system and broaden their application scope, this paper optimized and manufactured an ejector based on a one-dimensional thermodynamic model. An experimental platform was constructed to study the operating parameters impact on system performance. The experimental system can operate normally if the generator temperature is higher than 73 °C, the evaporator temperature can drop to as low as 12℃. Experimental results show that with increasing generator and evaporator temperatures, the system’s entrainment ratio and coefficient of performance (COP) increase; however, they decrease with a rise in condenser temperature, as well as with a reduction in working fluid flow rate and an increase in cooling water temperature. The study found that reducing the condenser temperature and pressure is an effective approach to boosting system efficiency. Furthermore, in comparison with a conventional refrigeration system, the ejector-integrated refrigeration system demonstrated a COP improvement rate approaching 20.8 % and a refrigeration capacity increase of nearly 5 %. These research findings can provide valuable references for researching ejector-integrated refrigeration system.