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

The regeneration-labyrinth sealing has been employed in the G-M refrigerator first with the cold regenerator outside the displacer. Sealing effects of the new structure, the sealing rings with opening, and the ones without opening have been compared. The performance of the cryocooler with these three sealing structures has also been contrasted. At the same time, influences of the displacer-cylinder gap and regenerative capacity of displacers on the performance of the cryocooler have been researched experimentally. The regeneration-labyrinth sealing is used in the G-M refrigerator with the cold regenerator inside the displacer (general structure) consequently. Influences of some parameters of the new type of sealing on the performance of the refrigerator were studied experimentally. The results of experiments illustrate that the cooling temperature of the second stage of the G-M refrigerator reaches 3.70 K, which marks the success of applying the regeneration-labyrinth sealing to the G-M refrigerator.