7–11 Jul 2014
Europe/Amsterdam timezone

40 K liquid Neon Energy Storage Unit

8 Jul 2014, 16:45
15m
WA2

WA2

Oral presentation (15min) C-14: New devices and novel concepts Tue-Af-Orals Session 5

Speaker

Mr Daniel Martins (CEFITEC, Departamento de Física, FCT - Universidade Nova de Lisboa, 2829-516 Caparica, Portuga)

Description

To attenuate temperature fluctuations, inherent to the cryocooler working or due to sudden heat bursts, a thermal Energy Storage Unit (ESU) could be used. The ESU directly coupled to the cold source actuates as a thermal buffer increasing temporarily its cooling capacity and providing a better thermal stability of the cold finger (“Power Booster mode”). The energy storage units presented here uses an enthalpy reservoir based on the high latent heat of the liquid to vapour transition of neon (38 K- 44 K) to store up to 900 J and a 6-liter expansion volume at RT in order to work as a closed system. Experimental results in the power booster mode will be described: the low temperature cell was directly coupled to the cold finger, its volume (≈12 cm3 of liquid neon) allowing to store 450 J around 40 K. 10 W heat bursts were applied, leading to liquid evaporation, with reduced temperature changes. The liquid neon reservoir can also provide a temporary cold source to be used after stopping the cryocooler allowing a vibration-free environment. In this case the enthalpy reservoir implemented (≈24 cm3) was linked to the cryocooler cold finger through a gas gap heat switch for thermal coupling/decoupling of the cold finger. We will show that, by controlling the enthalpy reservoir’s pressure, 900 J is stored at a constant temperature of 40 K as in a triple-point ESU.

Primary author

Mr Daniel Martins (CEFITEC, Departamento de Física, FCT - Universidade Nova de Lisboa, 2829-516 Caparica, Portuga)

Co-authors

Prof. Grégoire Bonfait (CEFITEC, Departamento de Física, FCT - Universidade Nova de Lisboa, 2829-516 Caparica, Portuga) Prof. Isabel Catarino (CEFITEC, Departamento de Física, FCT - Universidade Nova de Lisboa, 2829-516 Caparica, Portugal) Ms Patrícia Borges de Sousa (CEFITEC, Departamento de Física, FCT - Universidade Nova de Lisboa, 2829-516 Caparica, Portugal)

Presentation materials