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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-421-2

International Heat Transfer Conference 15
August, 10-15, 2014, Kyoto, Japan

An Analytical Study of the Heat Transfer in a Regular-Shaped Micro-Channel Type Stirling Regenerator

Get access (open in a dialog) DOI: 10.1615/IHTC15.fcv.008952
pages 3063-3074

Аннотация

In order to avoid the high flow frictional loss associated with conventional wire mesh Stirling regenerators, a micro-channel type Stirling regenerator, formed by hundreds of stacked and aligned porous sheets that are fabricated through an etching process is introduced. An analytical solution is derived for the transient heat transfer characteristics of the reciprocating laminar flow under prescribed wall temperature profiles. The temporal Nusselt number is expressed in terms of crank angle, kinetic Reynolds number, dimensionless fluid oscillating amplitude and Prandtl number. The obtained cycle-averaged Nusselt number has an almost constant value of 6.0 in the kinetic Reynolds number range of 0.01~1.0, significantly higher than the known analytical values of 4.36 and 3.66 for fully developed unidirectional laminar flow under constant temperature and constant heat flux wall boundary conditions respectively, which might be attributed to the disturbance and reduction of boundary layer by the reciprocating flow. Subsequently, optimization based on the first and the second thermodynamic laws is carried out for given design criteria and operating condition. The results show that, the micro-channel type porous-sheets regenerator has remarkably lower flow friction loss than the traditional wire mesh regenerators while maintaining high thermal effectiveness, thus leading to significantly lower total entropy generation rate and higher comprehensive performance.