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A Si/Glass Bulk-Micromachined Cryogenic Heat Exchanger for High Heat Loads: Fabrication, Test, and Application Results.
- Source :
- Journal of Microelectromechanical Systems; Feb2010, Vol. 19 Issue 1, p38-47, 10p, 5 Black and White Photographs, 1 Chart, 11 Graphs
- Publication Year :
- 2010
-
Abstract
- This paper reports on amicromachined Si/glass stack recuperative heat exchanger with in situ temperature sensors. Numerous high-conductivity silicon plates with integrated platinum resistance temperature detectors (Pt RTDs) are stacked, alternating with low-conductivity Pyrex spacers. The device has a 1 × 1-cm<superscript>2</superscript> footprint and a length of up to 3.5 cm. It is intended for use in Joule-Thomson (J-T) coolers and can sustain pressure exceeding 1 MPa. Tests at cold-end inlet temperatures of 237 K-252 K show that the heat exchanger effectiveness is 0.9 with 0.039-g/s helium mass flow rate. The integrated Pt RTDs present a linear response of 0.26%-0.30%/K over an operational range of 205 K-296 K but remain usable at lower temperatures. In self-cooling tests with ethane as the working fluid, a J-T system with the heat exchanger drops 76.1 K below the inlet temperature, achieving 218.7 K for a pressure of 835.8 kPa. The system reaches 200 K in transient state; further cooling is limited by impurities that freeze within the flow stream. In J-T self-cooling tests with an external heat load, the system reaches 239 K while providing 1 W of cooling. In all cases, there is an additional parasitic heat load estimated at 300-500 mW. [ABSTRACT FROM AUTHOR]
- Subjects :
- HEAT exchangers
HEAT transfer
DETECTORS
CRYOELECTRONICS
COOLING
Subjects
Details
- Language :
- English
- ISSN :
- 10577157
- Volume :
- 19
- Issue :
- 1
- Database :
- Complementary Index
- Journal :
- Journal of Microelectromechanical Systems
- Publication Type :
- Academic Journal
- Accession number :
- 48381515
- Full Text :
- https://doi.org/10.1109/JMEMS.2009.2034322