Thermal performance of a single stage double inlet pulse tube refrigerator: experimental investigation and CFD simulation

Abstract

ABSTRACT The pulse tube refrigerator is a closed cycle mechanical refrigerator with no mobile components working in a low-temperature area. The pulse tube refrigerator provides significant potential and has certain benefits viz., vibration-free, huge reliability, and economical for long span performance. In this paper, the experimental investigations performed on a single-stage Gifford-McMahon type double inlet pulse tube refrigerator (DIPTR) are reported. The experimental test-rig is built and operated to characterize the system performance at different values of average pressure, orifice valve opening, and double inlet valve opening. A three-dimensional comprehensive time-related computational fluid dynamic (CFD) DIPTR model is developed and the numerical simulation is performed in FLUENT to predict the performance with helium gas as a refrigerant. The CFD study helped to explain the thermal periodic characteristics occurring in the system and determined the cooling rate and phase relation between the pressure and flow rate. Experimental studies indicated that with an increase in the pressure (1.2 MPa) and at optimal valve openings of the double inlet (80%) and orifice (35%), 198 K lower temperature is attained. The computational outcome has been corroborated with the experimental observations. The comparison showed that the experimental observation is quite comparable with the computational prediction.