"Stack/Heat-Exchanger for a Thermoacoustic Heat Engine"

 

Inventors:  Dr. Julian D. Maynard et al.

PSU Invention Disclosure No. 97-1774

Licensing Contact:  Richard M. Weyer

 

 

Field of Invention:

            An improved convective heat-exchanger design for a thermoacoustic refrigerator.

 

Description:

            The level of interest in the thermoacoustic effect has heightened in recent years as alternatives for refrigeration technologies are sought to replace the use of chloro-flouro-carbons (CFC’s).  A key to the success of a thermoacoustic refrigerator is the heat-exchanger unit at the ends of the thermal stack.  Dr. Maynard has invented a design for a heat-exchanger that has the following advantages:

 

·         the heat-exchanger is incorporated directly into the stack

·         the heat-exchanger/stack unit is anisotropic promoting lateral heat flows

·         the heat-exchanger carries a fluid allowing for convective heat transfer

·         the heat-exchanger and stack have matching length scales for improved thermal contact with the thermoacoustic gas

 

The schematic below shows the stack/heat-exchanger design.  The design consists of “pin-stack” of thin plates with etched openings and thin-walled tubes (0.025 mm) of diameter 0.60 mm.  The small diameter tubing allows for the transport of high heat loads via laminar flow and provides the opportunity for graded exchanges with an external heat exchanger.