Heat transfer enhancing device
AssigneeUnited Technologies Corporation
InventorsWalter M. Presz, Jr., Robert W. Paterson, Michael J. Werle
Life of this patent
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Abstract
In a heat exchanger, a convoluted plate disposed in a fluid stream flowing in an axial direction generates adjacent counterrotating, large scale axial vortices downstream thereof adjacent a wall over which the fluid flows. The convoluted plate is constructed to produce minimum pressure losses, while the vortices increase the heat transfer rate between the fluid and the wall.
Claims20
Heat exchanger apparatus comprising:
- wall means defining a fluid flow channel and having a first surface portion over which a first fluid is adapted to flow in a downstream direction for transferring heat energy between the fluid and said wall means;
- and
- heat transfer means disposed upstream of said first surface portion for enhancing the exchange of heat energy between the fluid and said wall means, said heat transfer means comprising a thin vortex generating wall having oppositely facing sides, the fluid adapted to flow over both of said sides in a downstream direction, said vortex generating wall being a thin plate having an exposed downstream edge such that fluid flowing over both of said sides can mix together at said downstream edge, said plate comprising a plurality of adjoining, alternating lobes and troughs, each lobe and trough extending in the downstream direction to said downstream edge, said troughs increasing in depth in the downstream direction from a minimum at said troughs' upstream ends, said first surface portion being disposed downstream of said downstream edge, each lobe on one side of said wall having a corresponding trough opposite thereto on the other side of said wall such that said wall and said downstream edge are wave shaped, the contour and dimensions of said troughs and lobes being selected to insure that each trough flows full throughout its length, said vortex generating wall being located and said lobes and troughs being configured to generate a plurality of adjacent vortices downstream of said downstream edge adjacent said first surface portion, adjacent vortices rotating in opposite directions about respective axes extending in a first direction which is the direction of bulk fluid flow adjacent said lobes and troughs.
A tube and plate type heat exchanger including a plurality of spaced apart, parallel, thin first plates defining a plurality of first fluid flow channels therebetween adapted to have a first fluid flow therein, said plates each having a downstream end portion and an upstream edge, said end portion having an exposed downstream edge such that a fluid flowing over both of said sides can mix together at said downstream edge, said downstream end portion comprising a plurality of adjoining, alternating lobes and troughs, each lobe and trough initiating downstream from said upstream edge and extending in the downstream direction to said downstream edge, each lobe on each side of said wall having a corresponding trough opposite thereto on the other side of said wall such that said wall and said downstream edge are wave shaped, said troughs increasing in depth in the downstream direction from a minimum depth at their upstream ends, the contour and dimensions of said troughs and lobes being selected to insure that each trough flows full throughout its length and generates a pair of adjacent vortices downstream of said downstream edge and which rotate in opposite directions about respective axes extending in the downstream direction, said heat exchanger also including a plurality of thin, parallel, spaced apart second pates disposed immediately downstream of said first plates and defining a second fluid flow channel between each pair of adjacent second plates, each of said second channels having an upstream, inlet end aligned with the downstream edge of a respective one of said first plates such that the counterrotating vortices generated by each of said first plates is directed into said second channel aligned therewith.
Dependencies are inferred from the claim text.