新型制冷工质R450A用于喷射制冷循环性能研究

The new refrigerant R450A is an alternative to R134a for environmental protection. However, related research is limited which mainly focuses on simple compression refrigeration cycle. In this study, a mathematical model of ejector was constructed and the performance of R450A under different working conditions and ejector characteristics in a new ejector refrigeration cycle was studied. The results show that the secondary fluid pressure drop and area ratio between primary fluid and secondary fluid have parabolic profiles on COP, volumetric refrigerating capacity and ejector compression efficiency. The optimal secondary fluid pressure drop is 10 kPa and the area ratio is 7. Moreover, these values increase with the increase of condensing temperature. In addition, the COP and volumetric refrigerating capacity of R450A increase 14.6%~20.6% and 21.1%~21.7% respectively in the new ejector refrigeration cycle when compared with traditional vapor compression refrigeration cycle. Ejector nozzle efficiency and diffuser chamber have significant effects on system performance, and the nozzle efficiency shows stronger effect than the diffuser chamber.