Evaporator with enhanced condensate drainage
AssigneeDelphi Technologies, Inc.
InventorsSteven R. Falta, Mohinder Singh Bhatti, Shrikant Mukund Joshi, Gary Scott Vreeland
Life of this patent
Estimating the term…
Abstract
An evaporator (10) with opposed pairs of generally vertically oriented flow tube surfaces (14) has corrugated air fins in which the tube surface spacing c, the interior radius r of a crest (20) joining adjacent pairs of fin walls (18), the fin pitch p separating adjacent crests (20), and the length l of louvers (22) cut out of the fin walls (18) bear the following relationship: 0≦r/c≦0.057, 0.89≦l/c≦1.01, and 0.29≦p/c≦0.43. This has been found to substantially improve condensate drainage, while not significantly penalizing heat transfer or air side pressure drop.
Claims2
In an evaporator (10) having substantially parallel, substantially vertically oriented refrigerant flow tubes (12), said tubes having opposed pair of surfaces (14) spaced apart by a distance c, between which tube surfaces (14) corrugated air fins (16) are located, said fin corrugations comprised of adjacent pairs of fin walls (18) joined at integral crests (20) having an interior radius r and a fin pitch p, said fin walls (18) also comprising louvers (22) having a length l, characterized in that,
- said tube surface spacing c, crest interior radius r, fin pitch p, and fin louver length l have the following relationship:
- 0≦r/c≦0.057
- 0.89≦l/c≦1.01
- 0.29≦p/c≦0.43,
- said louver length l further being sufficient that that the ends of said louvers (22) partially overlap when viewed in a direction substantially parallel to said fin crests (20).
In an evaporator (10) having substantially parallel, substantially vertically oriented refrigerant flow tubes (12) that carry refrigerant sufficiently cold to cause condensation from humid air forced over said tubes (12) and on surfaces in thermal contact with said tubes (12), said tubes (12) having opposed pair of surfaces (14) spaced apart by a distance c and between which tube surfaces (14) corrugated air fins (16) are located, said fin corrugations comprised of adjacent pairs of fin walls (18) having facing interior surfaces joined at integral crests (20), said crests (20) having an interior surface radius r and a fin pitch p and the exterior surfaces of which crests (20) are in thermal contact with said tube surfaces (14), and in which a meniscus of retained condensed water forms in the interior surface of said crest (20) and bridging between the majority of said fin wall facing interior surfaces to form a restricted open space O bounded by the terminal edge of said meniscus, the exterior surfaces of the crests of adjacent crests (20), and the tube surfaces (14), said fin walls (18) also comprising louvers (22) having a length l and a louver opening adjacent to said louvers (22), characterized in that,
- said fin crest interior radius r, fin pitch p and tube spacing c have a relative relationship such that said fin walls (18) form a general V shape with a radius r small enough to create sufficient surface tension force to pull said meniscus of condensed water continually toward the interior surface of said crest (20), and said louver length l is long enough to overlap sufficiently with said meniscus to provide a drainage path that continually drains water from said meniscus, reducing the size thereof and enlarging the size of said open space O, said values of r, p c and l having the following relationship:
- 0≦r/c≦0.057
- 0.89≦l/c≦1.01
- 0.29≦p/c≦0.43,
- said louver length l further being sufficient that that the ends of said louvers (22) partially overlap when viewed in a direction substantially parallel to said fin crests (20).
Dependencies are inferred from the claim text.