| Auto-cascade refrigeration cycle system can effectively produce a satisfactory low temperature environment.This paper makes a theoretical analysis of the thermodynamic properties of the refrigerant,and A three-stage auto-cascade refrigeration system cycle experiment was conducted.With the help of computer software,the process of the three-stage auto-cascade refrigeration cycle system is simulated.Although the reliability of simulation calculation results needs to be further studied,with the improvement of the phase balance theory of mixed working fluid and the improvement of experimental data,the use of computer software for the simulation of a three-stage auto-cascade refrigeration cycle system has great advantages.The advantage of this method is that it saves costs and time,and also avoids danger compared with traditional experiments,ensuring our safety and unnecessary losses.The main contents are as follows:1.The research progress of the auto-cascade refrigeration cycle system and the current research situation at home and abroad are briefly described,and the advantages of the autocascade refrigeration cycle system and its significance to the refrigeration industry are pointed out.2.A three-stage auto-cascade refrigeration cycle system test bench was set up,and experiments were performed using R22/R23/R14 as mixed refrigerants.The evaporation temperature of-90℃ was prepared,the experimental data was obtained,and the COP of the system was calculated.3.Established the three-stage auto-cascade refrigeration system process,and used computer software to simulate the R22/R23/R14 three-stage auto-cascade refrigeration system.The results of the simulation calculation are compared with the experimental data,which proves the accuracy of the experiment and the feasibility of the simulation software used in the three-stage auto-cascade refrigeration system.4.Select R290 instead of R22 for system simulation.The R290/R23/R14 three-stage autocascade refrigeration system process was constructed,the factors that influence the operation of the system are obtained,and the proportion of non-azeotropic mixed refrigeration is the main factor.5.Calculate the theoretical ratio of mixed refrigerants for two three-stage auto-cascade refrigeration systems.When the ratio of the two mixed refrigerants is the same,through the comparison of the two three-stage auto-cascade refrigeration systems,it is found that under the same operating conditions,all aspects of the performance of the three-stage auto-cascade refrigeration system with R290 as the high-temperature refrigerant are better than the R22 autocascade refrigeration system. |
