This invention relates generally to refrigeration systems and, more particularly, to condensers for refrigerators.
Refrigeration systems typically include a compressor coupled to a condenser so that a compressed refrigerant flows to the condenser. See, for example, U.S. Pat. No. 5,711,159. A condenser fan circulates air over a surface of the condenser to cool the compressed refrigerant and is powered by a condenser fan motor.
Condenser surfaces for refrigerators are typically of tube and wire construction in which a refrigerant tube, or condenser coil, including a plurality of U-shaped segments is attached to a plurality of substantially parallel wires. In one type of condenser, a plurality of tube and wire members are placed in parallel rows underneath a refrigerator cabinet in an air flow path extending from a front of the refrigerator cabinet. See, for example, U.S. Pat. No. 5,592,829 However, this requires an increased distance between the refrigerator cabinet and a floor to provide adequate air access to the condenser surfaces, and, more importantly, suffers from reduced efficiency due to unevenly distributed airflow across the condenser surfaces and airflow parallel to the refrigerant tubes and/or wires. Air flowing through a relatively small air path through a lower front of the refrigerator produces relatively high air velocity and pressure drop of the air, which reduces an airflow rate across the condenser, increases noise, and reduces condenser efficiency. The reduced condenser efficiency results either in a decreased energy efficiency of the refrigerator or an increased cost in the condenser because of extra coil that is required to obtain a required heat transfer to the air.
Rectangular or cube shaped condensers have been developed to reduce the condenser volume and conserve space. See, for example. U.S. Pat. No. 5,685,166. However, these condensers also suffer efficiency losses due to uneven airflow over the condenser surfaces and airflow parallel to the condenser surfaces. Thus, extra coil is often required to achieve a desired heat transfer to the air. Also, a considerable number of U-shaped elbows with small radiuses are required to fabricate the rectangular condenser shape, which increases condenser cost and decreases condenser reliability.
Accordingly, it would be desirable to provide a refrigerator condenser that more effectively transfers heat to the air, promotes even air flow across the condenser surface, reduces the need for extra condenser coil, and avoids the need for U-shaped elbows of small radius that compromise condenser reliability and increases condenser cost.
In an exemplary embodiment of the invention, a refrigerator condenser includes a longitudinal axis and a tube and wire member spiraled about the longitudinal axis. A passage extends through the tube and wire member between a first end and a second end. The second end is closed to prevent longitudinal air flow through the second end. Thus, when used with a condenser fan mounted in the first end, air is drawn into the passage substantially perpendicularly to an outside surface of the condenser and through the spiraled tube and wire member. The perpendicular airflow through the condenser surface maximizes heat transfer to the air, increases the efficiency of the condenser, and reduces the need for extra coil to achieve a selected heat transfer to the air. Moreover, the spiraled tube and wire member produces a compact condenser while avoiding the use of small radius elbows that increase the cost of the condenser and reduce condenser reliability.
In one embodiment, wraps 48 are layered about longitudinal axis 42 in an Archimedes spiral defined by the relationship
R=Aθ
where A is a selected constant, θ is an angular distance from a beginning, or center, of the spiral, and R is a radial distance to a point in the spiral from the center of the spiral. Therefore, R constantly increases along each wrap 48, and a distance between adjacent wraps 48 is approximately equal from one wrap to the next. In a further embodiment, each wrap includes segments of an Archimedes spiral having different center points to facilitate manufacturing of spiraled tube and wire member 10. Other types of spirals, with or without multiple centers for the wraps, and with or without substantially uniform distance between the wraps, are employed in various alternative embodiments without departing from the scope of the invention.
A baffle 68 is mounted at condenser second end 18 to prevent longitudinal air flow parallel to wires 14 that decreases heat transfer efficiency. Fan blade 62 is mounted at condenser first end 16 external of opening 44 and draws air through condenser 40 substantially perpendicular to condenser outer surface 24 and longitudinally after condenser 40 and toward compressor 64 to cool compressor 64 as well. In alternative embodiments, other closure members besides baffle 68 are used to close condenser second end.
Thus, a compact, energy efficient and inexpensive condenser 40 is provided. Condenser 40 is easily fabricated by bending flat tube and wire member 10 (shown in
While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.
Number | Name | Date | Kind |
---|---|---|---|
1189470 | O'Brien | Jul 1916 | A |
1691180 | Carrey | Nov 1928 | A |
2311947 | Kucher | Feb 1943 | A |
2453448 | McTurk | Nov 1948 | A |
2561278 | Hill | Jul 1951 | A |
2620170 | Brickman | Dec 1952 | A |
2779173 | Wurtz | Jan 1957 | A |
3159213 | Wurtz | Dec 1964 | A |
3162023 | Smith | Dec 1964 | A |
3173479 | Heuer | Mar 1965 | A |
3388562 | Harle | Jun 1968 | A |
3460225 | Beauvais | Aug 1969 | A |
3524329 | Smith et al. | Aug 1970 | A |
3828575 | Mallosky | Aug 1974 | A |
3865517 | Simmons et al. | Feb 1975 | A |
3907025 | Malcosky et al. | Sep 1975 | A |
3908393 | Eubank | Sep 1975 | A |
3943728 | Maudlin | Mar 1976 | A |
4047393 | Hanson et al. | Sep 1977 | A |
4321803 | Smith | Mar 1982 | A |
4340115 | Wright et al. | Jul 1982 | A |
4723419 | Kessler et al. | Feb 1988 | A |
5038854 | Peterson, III | Aug 1991 | A |
5097678 | Aubuchon | Mar 1992 | A |
5211219 | Kawabata et al. | May 1993 | A |
5538075 | Eubank et al. | Jul 1996 | A |
5592829 | Kim | Jan 1997 | A |
5685166 | Li | Nov 1997 | A |
5778973 | Shin | Jul 1998 | A |
5806334 | Shin | Sep 1998 | A |
6435269 | Hancock | Aug 2002 | B1 |