d. Cryogenic temperature thermosyphons
The cryogenic heat pipes are used for the thermal control of radiation sensors in space. Radiation
sensors are used in satellites in order to measure infrared radiation emitted by the Earth. Their
efficiency is as high as their temperature is low. Usually, sensors operate in cryogenic temperatures
(< -150ºC). In order to refrigerate the sensor, it is necessary the use of a radiator or a cryogenic
refrigerator. However, very often the sensor and the refrigerator are placed relatively far away from
one another, due to the lack of physical space in the satellite. In this case, the heat pipe links
the sensor and the refrigerator in order to transfer the sensor heat to the refrigerator as efficiently
as possible.
The working fluid can be Helium, Hydrogen, or other gases. The LABTUCAL develop both theoretical and
experimental studies on cryogenic heat pipes. Such studies have become one Ph.D. thesis as well as
several articles published in national and international Journals and Conferences.
Publications:
COUTO, P.; MANTELLI, M. B. H.; OCHTERBECK, J. M. Experimental Analysis of Supercritical Startup of Nitrogen/Stainless Steel Cryogenic Heat Pipes. Journal of Thermophysics and Heat Transfer, v. 20, n. 4, p. 842-849, 2006.
COUTO, P.; OCHTERBECK, J. M.; MANTELLI, M. B. H. Analysis of Supercritical Startup of Cryogenic Heat Pipes With Parasitic Heat Loads. Journal of Thermophysics and Heat Transfer, v. 19, n. 4, p. 497-508, 2005.
COUTO, P.; MANTELLI, M. B. H.; MAROTTA, E. E.; FULLER, J. J. Parametric Analysis of Heat Transfer on Multistage Cryogenic Radiator. Journal of Thermophysics and Heat Transfer, 2002. vol.16, no.3, p.313-323.
COUTO, P.; MANTELLI, M. B. H. Transient Temperature Behavior of Multistage Cryogenic Radiators: Model and Experimental Validation. Journal of Thermophysics and Heat Transfer, 2000. vol.14, no.3, p.313-321.
