Development of refrigerators based on thermo-acoustics phenomenon

• Grant number: 97/07357-7
• Support Opportunities: Research Grants - Innovative Research in Small Business - PIPE
• Start date: January 01, 1998
• End date: August 31, 2001
• Field of knowledge: Engineering - Aerospace Engineering
• Principal Investigator: Humberto Pontes Cardoso
• Grantee: Humberto Pontes Cardoso
• Company: Equatorial Sistemas S/A
• City: São José dos Campos

Abstract

The recent progress in developing long-wave photovoltaic detectors for imagers installed in artificial satellites has created an increasing demand for highly reliable, low-weight and low energy consuming cryogenic refrigeration systems. Micro-cryogenic, thermo-acoustic refrigerators are being developed by the world’s main space research centers as an alternative to the passive refrigeration systems (cryogenic radiators) and thermoelectric refrigerators. Recent progress in microelectronics, especially in microprocessors, also requires highly reliable, lowweight micro refrigerators. Thermo-acoustic micro refrigerators consist of a stainless steel tube containing a mixture of gases (normally helium and xenon), a loud-speaker installed at one end and a thermo-acoustic dephaser (TAD) positioned inside the tube at the opposite end. In triggering the loudspeaker, compression and decompression waves are produced in the gas that give rise to successive heat exchanges between the various layers of TAD and the gas in such a way that, in the end, a quantity of heat is removed from the TAD that is greater than the one produced. This technology, as well as being very promising for use in space and in the local cooling of microcircuits, also seems to be an alternative for domestic refrigerators. (AU)