Accelerated heat exchanger

A heat transfer device comprising:

• a tube arranged in a serpentine path of elongated straight segments joined by u-shaped returns to form a plurality of parallel straight segments of the tube to carry a first fluid from a first fluid inlet to a first fluid outlet,
• a plurality of fins arranged in engagement with an exterior surface of the tube, each fin lying in a plane generally perpendicular to a length of the straight segments of the tube, the fins arranged to guide a second fluid flowing over the exterior surface of the tube to effect a heat transfer from one of the fluids to the other via thermal conduction through the fins and tube,
• an enclosure enclosing the tube and fins to define at least a part of a flow path for the second fluid in a region of the tube and fins from a second fluid inlet to a second fluid outlet,
• a wall interior of the enclosure to define a first section of the flow path for the second fluid in the enclosure which first section leads from the second fluid inlet and extends in a first direction substantially perpendicular to a length of the elongated segments of the tube, the wall further defining a second section of the flow path for the second fluid in the enclosure which second section extends in an opposite direction from the first section substantially perpendicular to the length of the elongated segments of the tube and leads to the second fluid outlet, the interior wall being shaped and arranged in the enclosure such that a cross sectional area of the flow path for the second fluid in the enclosure changes along its length from the second fluid inlet to the second fluid outlet.

A refrigeration appliance having a refrigeration circuit with

• a compressor, a condenser and an evaporator, wherein at least one of the condenser and evaporator includes a heat transfer device comprising:
• a tube having a first fluid inlet and a first fluid outlet, the tube arranged to form a plurality of generally parallel elongated segments of the tube,
• an enclosure enclosing the tube to define at least a part of a flow path for a second fluid over an exterior surface of the tube from a second fluid inlet to a second fluid outlet,
• a wall interior of the enclosure to define a first section of the flow path for the second fluid in the enclosure which first section leads from the second fluid inlet and extends across at least a first portion of a length of substantially all of the elongated segments of the tube, the wall further defining a second section of the flow path for the second fluid in the enclosure which second section extends across at least a second portion of the length of substantially all of the elongated segments of the tube and leads to the second fluid outlet, the interior wall being shaped and arranged in the enclosure such that a cross sectional area of the flow path for the second fluid in the enclosure changes along its length from the second fluid inlet to the second fluid outlet.