Theoretical And Experimental Study On The Ejector Refrigeration System With Binary Fluids

Ejection refrigeration is one of the most promising technologies.It can use industrial waste heat and other low-grade heat to obtain cold energy,but it has very low thermal efficiency.The binary fluids ejection refrigeration system proposed in this paper can effectively improve the performance of the ejection refrigeration system.Based on the laws of engineering thermodynamics such as Raoul's Law,a theoretical system for calculating the performance of a binary fluids ejection refrigeration system is formed.In this paper,the R 134a/R32 refrigerant pairs are used to compare the binary fluids ejection refrigeration system with conventional single-stage and two-stage ejection refrigeration systems.Research indicates:1)Under the same operating conditions,the performance of the binary fluids ejection refrigeration system is superior to the conventional one-stage ejection refrigeration system;2)The performance of the binary fluids ejection refrigeration system is not as good as that of the conventional two-stage ejection refrigeration system under the condition of low evaporation temperature and high condensing temperature.The performance of the binary fluids ejection refrigeration system is superior to that of the conventional two-stage injection refrigeration system under the condition of high evaporation temperature.The performance of the binary fluids ejection refrigeration system is studied theoretically.The results show that:1)The COP of the system increased with the increase of the generation temperature.2)The COP of the system increases with the increase of the evaporation temperature.3)The COP of the system decreases with the increase of the condensing temperature.These laws are in accordance with the rules of the conventional refrigeration system.In order to study the performance of the binary fluids ejection refrigeration system experimentally,an experimental platform was set up.The design and manufacture of the generator and the ejector are carried out.The heat exchanger,the throttle valve and the circulation pump are selected.The design power of the platform evaporator is 0.9 kW.The test bed has two operating modes,one mode is a single-stage jet refrigeration cycle in which the high-pressure stage operates independently,and the other mode is a binary fluids ejection refrigeration cycle.Switching between the two modes is possible using the valve switching method.The experimental results show that:1)Under the same operating conditions,the performance of R32 single-stage ejector refrigeration system is better than that of R134a single-stage ejector refrigeration system,in line with the theoretical research results;2)Under the same experimental conditions,the performance of the binary fluids ejection refrigeration system is improved by 10%-20%in the performance of single-stage ejection refrigeration system.The experimental results demonstrate the superiority of the binary fluids ejection refrigeration system.