BACKGROUND OF THE INVENTION
This invention relates generally to refrigerators, and more particularly, to condenser systems for refrigerators.
Refrigerators typically include a refrigeration unit including a condenser, a compressor, and an attached evaporator. The compressor and condenser are typically located in a machinery compartment formed into a refrigerator cabinet below a chilled refrigeration compartment for food storage. A fan induces a forced draft through the machinery compartment and across the condenser and compressor to remove heat from exterior surfaces of the compressor and condenser. See, for example, U.S. Pat. Nos. 4,156,352 and 5,117,523.
Conventional condenser systems are disadvantaged in several aspects. For example, increased condenser tube lengths are often employed to increase heat transfer efficiency. However, increasing the length of the condenser tube decreases the compactness of the condenser, which increases the required size of the machinery compartment and hence reduces available space inside the refrigeration compartment for food storage. Also, increasing a length of the condenser tube often entails increasing the number of tube joints, thereby introducing additional labor and material costs, presenting potential leaks in a refrigeration circuit, and negatively affecting a pressure drop of refrigerant through a transition portion of the tube and pressure drops across the compressor fan. Further, an increased number of joints may lead to undesirable rattling noises from tube dressings and decreased reliability of the condenser due to faulty or failed tube joints. Further still, many conventional condenser systems require periodic maintenance such as cleaning the coils of dust, dirt, and other debris that settles on the surface of the coils, decreases heat transfer efficiency and increases an operating temperature of the condenser system.
- BRIEF SUMMARY OF THE INVENTION
Accordingly, it would be desirable to provide a condenser system that increases heat transfer efficiency while maintaining a compact machinery compartment size, minimizing the number of tube joints, and minimizing system maintenance.
In an exemplary embodiment of the invention, a condenser system includes an integral condenser coil and hot gas loop for installation between an outer shell and an inner liner of a refrigerator cabinet. Integral construction of the hot gas loop with the condenser coil increases the condenser system heat transfer efficiency while minimizing the number of tube joints.
BRIEF DESCRIPTION OF THE DRAWINGS
More specifically, the refrigerator cabinet outer shell and inner liner together form a refrigeration compartment and a machinery compartment for housing a refrigeration unit. The refrigeration compartment includes a floor having a lower shelf surface, an upper shelf surface adjacent the machinery compartment and a substantially vertical wall extending from at least one of the upper and lower shelf surfaces. The integral condenser coil and hot gas loop includes a first portion coinciding with the floor upper shelf, a second portion coinciding with the floor lower shelf, and a third portion coinciding with the vertical wall when the integral condenser and hot gas loop is installed in the outer shell. The integral condenser coil and hot gas loop is foamed in place with the inner liner so that that the condenser system is embedded in the floor and a vertical wall of the refrigeration compartment, thereby forming a sealed, maintenance free refrigerator condenser system.
FIG. 1 is a perspective view partially broken away of a refrigerator cabinet including a condenser system;
FIG. 2 is a side sectional view of the refrigerator cabinet shown in FIG. 1;
FIG. 3 is a broken away rear view of the refrigerator cabinet shown in FIG. 1;
FIG. 4 is a perspective view of the condenser system shown in FIGS. 1-3;
FIG. 5 is a partial perspective view of a second embodiment of a condenser system; and
DETAILED DESCRIPTION OF THE INVENTION
FIG. 6 is a perspective view partially broken away of a refrigerator including a third embodiment of a condenser system.
FIG. 1 is a perspective view partially broken away of a refrigerator 10 including a generally rectangular cabinet 12 including an upper refrigeration compartment 14 and a lower machinery compartment 16 formed therein. Cabinet 12 includes a ceiling 18, a floor 20, a rear wall 22 connecting ceiling 18 and floor 20, a pair of side walls 24 adjacent rear wall 22 and connecting ceiling 18 and floor 20. A center wall 26 partitions an interior 28 of refrigerator 10 into refrigeration compartment 14 and a freezer compartment 30 accessible through a front face 32. A door (not shown in FIG. 1) is mounted to front face 32 to seal each of refrigeration compartment 14 and freezer compartment 30.
A condenser coil 34 is located under cabinet floor 20 of refrigeration compartment 14 and above an exterior surface 36 of machinery compartment 16. A plurality of fins 38 are attached to machinery compartment external surface 36 to enhance heat transfer through cabinet floor 20. Machinery compartment 16 is positioned a distance D, above a bottom 40 of refrigerator cabinet 12 to allow air to flow along an air path 42 below cabinet floor 20. A grill (not shown) in cabinet lower front face 44 allows passage of air to and from air path 42.
While the present invention is illustrated and described herein in the context of a side-by-side refrigerator, the invention could be practiced and the benefits accrued in other types of refrigerators. Therefore, the invention is not restricted to a particular type of refrigerator, such as refrigerator 10. Also, it is contemplated that the present invention could be used as a stand-alone system or in combination with conventional condenser systems to increase heat transfer efficiency.
FIG. 2 is a side sectional view of refrigerator 10 including cabinet 12 fabricated according to known methods and including an outer shell 60 fabricated from, for example, metal, and an inner liner 62 fabricated from, for example, plastic, with a foam insulation 64 therebetween, such as polyurethane foam. Condenser system condenser coil 34 is foamed-in-place adjacent a floor 66 of cabinet outer shell 60. Cabinet outer shell floor 66 includes an upper shelf surface 68 above machinery compartment 16, a substantially vertical wall surface 70, i.e., a wall surface having a vertical component, and a lower shelf surface 72 extending from substantially vertical wall surface 70. Cabinet inner liner 62 includes a corresponding floor 74 including an upper surface 76 and a lower surface 78 joined by a substantially vertical wall 80. In a particular embodiment, shell floor vertical wall surface 70 is substantially perpendicular to upper shelf surface 68, thereby forming a substantially rectangular machinery compartment 16. In alternative embodiments, one or more of outer shell floor surfaces 68, 70, and 72 are angled, curved, or otherwise oriented differently from exemplary refrigerator 10 without departing from the scope of the present invention.
Condenser coil 34 is generally planar adjacent each surface 68, 70, and 72 of outer shell floor 66 and includes substantially horizontal first and second portions 82 and 84 adjacent upper and lower shelf surfaces 68 and 72, respectively, and a vertical third portion 86 adjacent substantially vertical wall surface 70 of outer shell floor 66. Sheet metal fins 38 are attached to machinery compartment exterior surface 36 opposite shell floor surfaces 68, 70 and 72, including an interior 88 of machinery compartment 16, to increase a surface area for heat transfer through outer shell floor 66. Hence, metal fins 38 also include substantially horizontal portions 90 opposite substantially horizontal upper and lower shelf surfaces 68 and 72, respectively, and a vertical portion 92 opposite substantially shell floor vertical wall surface 70. A refrigeration unit 94 occupies machinery compartment 16 as described more fully below, and a door 96 seals closed refrigeration compartment 14.
FIG. 3 is a rear view of refrigerator 10 with cabinet 12 broken away. Refrigeration unit 94 includes a motor compressor unit 120 that accepts refrigerant from a condenser system discharge tube 122 and discharges compressed refrigerant into a condenser system inlet tube 124. From condenser system inlet tube 124, refrigerant flows thorough condenser coil 34 and an integral hot gas loop 126 extending upwardly through refrigerator center wall 26 between refrigeration compartment 14 and freezer compartment 30, across cabinet ceiling 18, and extending downwardly to outer shell lower shelf surface 72 (not shown in FIG. 3) and to condenser system discharge tube 122. A filter dryer 128 is connected to condenser system discharge tube 122, and a discharge line 130 carries refrigerant passed through filter dryer 128 to a suction line 132 connected to an evaporator (not shown) according to known methods in the art. A condenser fan 134 is driven by a fan motor (not shown) to force air across a surface 136 of motor compressor unit 120 and across surfaces of fins 38 (shown in FIG. 2) to enhance heat transfer from compressor surface 136 and fins 38, respectively to ambient air.
FIG. 4 is a perspective view of a condenser system 150 including integral condenser coil 34 and hot gas loop 126. Condenser coil 34 is serpentine shaped and fabricated according to known methods. Condenser system inlet tube 124 delivers refrigerant to condenser coil 34 including first portion 82 coinciding with outer shell floor upper shelf surface 68 (shown in phantom), second portion 84 coincident with outer shell floor lower shelf surface 72 (shown in phantom) and third portion 86 coinciding with outer shell vertical wall surface 80 (shown in phantom) when condenser system 150 is installed into cabinet outer shell 60 (shown in FIG. 2) and cabinet 12 is formed. Hence condenser coil 34 includes horizontal portions 82, 84 and a vertical portion 86. Hot gas loop 126 extends upwardly from condenser coil second portion 84 and is coincident with refrigeration compartment front face 32 (shown in FIG. 1) when condenser system 150 is installed into cabinet outer shell 60 and cabinet 12 is formed. A stepped hot gas loop tube 126 extends along outer shell floor 66 from a lower portion 154 of hot gas loop 126 to condenser system discharge tube 122.
In an alternative embodiment, hot gas loop 126 extends upwardly and coincides with another of vertical cabinet side walls 24 or cabinet rear wall 22. In other alternative embodiments, hot gas loop 126 includes portions coincident with cabinet outer shell floor 66 when condenser system 150 is installed and cabinet 12 is formed, and serpentine condenser coil 34 extends upwardly along one or more of cabinet side walls 24 and cabinet rear wall 22 (shown in FIG. 1).
FIG. 5 is a partial perspective view of a second embodiment of a condenser system 200 in which a first set of sheet metal fins 202 extend from a machinery compartment exterior surface 204 opposite a shell floor lower shelf surface 206 and are longitudinally oriented perpendicular to straight segments 208 of a serpentine condenser coil second portion 210. A second set of sheet metal fins 212 are oriented parallel to serpentine condenser coil straight segments 208 to achieve a desired heat transfer rate from condenser coil 214 to ambient air through an outer shell floor 216 and sheet metal fin sets 202 and 212. In various alternative embodiments, sheet metal fin sets 202 and 212 could be oriented at various angles with respect to condenser coil first 218, second 210, and third 220 portions, respectively, to achieve a desired heat transfer rate and to improve or impede airflow across fin sets 202 and 212.
FIG. 6 is a perspective view partially broken away of a refrigerator 300 including a third embodiment of a condenser system 302 including condenser coil 304 extending upwardly along a rear wall 306 of a refrigerator cabinet 308. Vertically extending fins 310 are attached to an exterior surface 312 of rear wall 306 to enhance heat transfer to ambient air. An integral hot gas loop (not shown in FIG. 6) extends from condenser coil 304 along one or more of cabinet ceiling 314, side walls 316, floor (not shown), and front face (not shown) of refrigerator cabinet 308. A condenser fan (not shown) located in a machinery compartment (not shown in FIG. 6) forces ambient air underneath refrigeration compartment floor (not shown) and across fins 310 on cabinet rear wall 306 in a direction indicated by arrows 320.
In all of the described embodiments, integral condenser system with a hot gas loop increases heat transfer efficiency to ambient air while minimizing a number of tube joints that reduce reliability of condenser system. Elimination of joints reduces labor and material cost, as well as potential rattles from tube dressing and imperfect connections. Undesirable pressure drops from extra joints are further avoided, which reduces potential turbulence and noise within condenser system. Also, because condenser system is cast in place in a refrigerator cabinet, condenser system is compact and does not occupy or impede interior space of refrigerator and/or freezer compartments. Cast-in-place installation also immunizes condenser system from dust, dirt, and debris that requires periodic cleaning and maintenance in conventional condenser systems.
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.