Modeling and Experimental Analyzes of Two-Phase Recuperation Heat Transfer in Systems Using Mixed-Refrigerant

Efficient heat recuperation is one of the crucial aspects affecting the performance of mixed-refrigerant Joule-Thomson (MR JT) cryocoolers. This becomes even more important in the case of precooled systems which improves the performance, but on the other hand, emphasizes the challenges related to the effectiveness of the recuperation process. Modelling of recuperation process is challenging itself as recuperation concerns both gaseous, liquid phases and two-phase flow. Moreover, application of mixed-refrigerant brings a lot complexity to the modelling of MR thermo-hydraulic properties. At last, experimental validation of modelling results requires very sophisticated measurement setup especially in terms of mixed-refrigerant composition which can significantly differ from charged proportions. This paper present modelling approach of complete two-phase recuperation heat transfer process. In total, 96 correlations combinations were examined. The results are compared with the experimental results achieved using novel validated method of noninvasive, continuous method of determining composition. Carried modelling validated with experimental results provides useful insight concerning heat transfer phenomena in recuperation section of MR JT cryocoolers or other mixed-refrigerant based systems.