Study on a new type of sealing - regeneration-labyrinth sealing for displacer in cryocoolers: Part II - Experimental study

The regeneration-labyrinth sealing has been employed in the G-M refrigerato r first with the cold regenerator outside the displacer. Sealing effects of the new structure, the sealing rings with opening, and the ones without op ening have been compared. The performance of the cryocooler with these thre e sealing structures has also been contrasted. At the same time, influences of the displacer-cylinder gap and regenerative capacity of displacers on t he performance of the cryocooler have been researched experimentally. The r egeneration-labyrinth sealing is used in the G-M refrigerator with the cold regenerator inside the displacer (general structure) consequently. Influen ces of some parameters of the new type of sealing on the performance of the refrigerator were studied experimentally. The results of experiments illus trate that the cooling temperature of the second stage of the G-M refrigera tor reaches 3.70 K, which marks the success of applying the regeneration-la byrinth sealing to the G-M refrigerator. (C) 2000 Elsevier Science Ltd. All rights reserved.