Impingement heat exchanger for stirling cycle machines

A heat exchanger for a Stirling cycle machine comprising:

• an inlet for receiving working fluid;
• an impingement baffle having a plurality of apertures thereon;
• a manifold formed in the space between the interior wall of said Stirling cycle machine and said impingement baffle;
• wherein said working fluid is caused by the impingement baffle to impinge upon said interior wall of said Stirling cycle machine when said working fluid is flowing in a first direction, thereby increasing heat transfer, and said working fluid is caused by the impingement baffle to be directed into said manifold when said working fluid is flowing in a second direction, thereby decreasing heat transfer.

A method for transferring heat to and from working fluid within a Stirling cycle machine comprising the steps of:

• providing an expansion chamber defined in a cylinder by a piston;
• providing a compression chamber defined in said cylinder by said piston;
• causing said working fluid to flow between said compression chamber and said expansion chamber via at least one passageway;
• wherein said passageway comprises a heat exchanger, said heat exchanger including an impingement baffle arranged to direct said working fluid so as to provide a substantially higher heat transfer function when said working fluid flows in a first direction due to the impingement baffle causing impingement of the working fluid on a heat transfer surface during flow in the first direction, as opposed to a lower heat transfer function when said working fluid flows in a second direction, due to said working fluid flowing past the heat transfer surface and through the impingement baffle away from the heat transfer surface during flow in the second direction.

A Stirling cycle machine operating via the compression and expansion of a working fluid, said Stirling cycle machine comprising:

• an expansion chamber defined in a first cylinder by a piston;
• a compression chamber defined in a second cylinder by said piston;
• said expansion chamber and said compression chamber in communication via at least one passageway;
• said passageway comprising an impingement heat exchanger which includes an impingement baffle arranged to direct said working fluid so as to provide a substantially higher heat transfer function when said working fluid flows in the direction toward said compression chamber, due to the impingement baffle causing impingement of the working fluid on a heat transfer surface during flow in the direction toward said compression chamber, as opposed to a lower heat transfer function when said working fluid flows toward said expansion chamber, due to said working fluid flowing past the heat transfer surface and through the impingement baffle away from the heat transfer surface during flow in the direction toward said expansion chamber.