Investigation on the dynamic adsorption characteristics of activated carbon to Helium-4 for 4-20 K regenerator of cryocoolers

Abstract

With the advantages of long life and high reliability, cryocoolers gradually substitute cryogenic liquids to become a critical guarantee for the stable operation in space exploration. For cryocoolers, the regenerator is a key component that strongly influences its refrigeration performance. The specific heat of current commonly-used regenerator materials below 20 K is significantly lower than that of the working gas Helium-4, resulting in insufficient cold storage capacity of the regenerator and further limiting the cryocooler’s ability to obtain lower temperatures and larger cooling capacity. In this paper, activated carbon is used to absorb a part of helium in the regenerator to replace the traditional magnetic regenerator materials. By establishing a low-temperature dynamic adsorption model, the dynamic adsorption characteristics of activated carbon to Helium-4 in the temperature range of 4-20 K were studied, and the effect of its microscopic adsorption/desorption heat effect on the performance of the regenerator was investigated.