Noninvasive and continuous method of binary and ternary mixture composition measurement

• New method of noninvasive, continuous mixture composition measurement was proposed • Method was checked for binary mixture and then extended to ternary mixture • Method was validated against gas chromatography for binary mixture • Method was preliminarily validated against gas chromatography for ternary mixtures • The influence of system parameters on binary mixture composition was investigated The shift between the composition of a mixed-refrigerant charged into the system and the composition during its operation is not fully recognized phenomena in mixed-refrigerant Joule-Thomson (MR JT) cryocoolers. This phenomenon introduces significant uncertainty in the measurement and analysis of MR JT cryocoolers. This can also significantly affect the performance of the cryocooler. Currently, the most popular and widely used method is to probe the mixture and analyze it on gas chromatography. However, this method has drawbacks, including influence on the remaining portion of MR in the system. Moreover, this method is valid only for the given moment of probing, and it is not suitable for continuous measurements that are critical for the analysis of transient phenomena. This paper presents a novel method for the continuous determination of the composition of binary and ternary mixtures. The method has been validated against the chromatography method.