40 K Liquid Neon Energy Storage Unit

D. Martins, P. Borges de Sousa, I. Catarino, G. Bonfait
2015 Physics Procedia  
A thermal Energy Storage Unit (ESU) could be used to attenuate inherent temperature fluctuations of a cold finger, either from a cryocooler working or due to suddenly incoming heat bursts. An ESU directly coupled to the cold source acts as a thermal buffer temporarily increasing its cooling capacity and providing a better thermal stability of the cold finger ("Power Booster mode"). The energy storage units presented here use an enthalpy reservoir based on the high latent heat of the
more » ... of the liquid-vapour transition of neon in the temperature range 38 -44 K to store up to 900 J, and that uses a 6 liters expansion volume at room temperature in order to work as a closed system. Experimental results in the power booster mode are described: in this case, the liquid neon cell was directly coupled to the cold finger of the working cryocooler, its volume ( 12 cm 3 ) allowing it to store 450 J at around 40 K. 10 W heat bursts were applied, leading to liquid evaporation, with quite reduced temperature changes. The liquid neon reservoir can also work as a temporary cold source to be used after stopping the cryocooler, allowing for a vibration-free environment. In this case the enthalpy reservoir implemented ( 24 cm 3 ) was linked to the cryocooler cold finger through a gas-gap heat switch for thermal coupling/decoupling of the cold finger. We show that, by controlling the enthalpy reservoir's pressure, 900 J can be stored at a constant temperature of 40 K as in a triple-point ESU.
doi:10.1016/j.phpro.2015.06.188 fatcat:rwkjo54chzgc5krcwzlzobdvfq