Evaluation of a Cryocooler Simulation Based on In-Situ Measurement of the Working Fluid Inside the Pulse Tube Refrigerator

In this study, a two-stage pulse tube refrigerator was modeled and numerically analyzed using Sage (Gedeon Associates). In addition, a new measurement system was developed to simultaneously measure the pressure, temperature, and mass flow rate of the working gas under reciprocating flow and extremely low-temperature conditions below 4 K, which had previously been considered technically difficult. This system provides deeper insight into the thermodynamic behavior within the refrigerator. This paper presents a comparison between the experimental results obtained using the developed measurement system and the numerical results calculated with Sage, and reports the evaluated applicability and valid operating range of the pulse tube refrigerator simulation model.