Development of a 15 K hydrogen-based sorption cooler

At the University of Twente, a 15 K hydrogen-based sorption cooler is under development, which has no moving parts and, therefore, is essentially vibration-free. Moreover, it has the potential of a very long life. Although the cooler may operate standalone, it is designed to precool a helium-based sorption cooler thats establishes 5 mW at 4.5 K, requiring a cooling power of 25 mW at the hydrogen stage. Both coolers use microporous activated carbon as the adsorption material. The combination of these two cooler stages needs a total of 5.4 W of input power and is heat sunk at two passive radiators at temperatures of about 50 K and 90 K (1.9 W and 3.5 W, respectively). We developed and built a demonstrator of the helium cooler under a previous ESA-TRP contract, and in 2008 we started a new ESA-sponsored project aiming at the development of the hydrogen stage. In the paper, the preliminary design of this hydrogen-cooler is presented, along with introductory experiments on its Joule-Thomson cold stage. © 2010 American Institute of Physics.