Foul-Resistant Condenser Using Microchannel Tubing

Abstract

A condenser coil for a refrigerated beverage and food service merchandiser includes a plurality of parallel flat, multichannel heat transfer tubes and a plurality heat transfer fins extending between adjacent tubes in a generally V-shaped zig-zag pattern. In order to reduce the likelihood of fouling by the bridging of fibers therebetween, the fins are spaced apart at a dimension, w, as measured from apex to apex, of at least about 0.25 inches. In an embodiment, the plurality of heat transfer fins extend between adjacent tubes in a generally V-shaped zig-zag pattern at a spacing, as measured from apex to apex, in the range of from about 0.4 to about 0.8 inches. In an embodiment, the plurality heat transfer fins extend between adjacent tubes in a generally V-shaped pattern at a spacing, as measured from apex to apex, in range of from about ⅓ inches to about ½ inches.

1 . A refrigerated merchandiser comprising:
 an enclosure defining a refrigerated display cabinet and having an access opening for providing access to the refrigerated display cabinet;   an evaporator coil disposed in operative association with the refrigerated display cabinet; and   a condenser coil connected in refrigerant flow communication with said evaporator coil, said condenser coil having a plurality of refrigerant carrying members aligned in generally parallel relationship and a plurality of fins connected in heat transfer relationship with and extending between adjacent members of said plurality of refrigerant carrying members, said plurality of fins being spaced apart at a spacing of at least 0.4 inches between adjacent fins.   
   
   
       2 . A refrigerated merchandiser as recited in  claim 1  wherein said plurality of fins comprises a plurality of fins extending generally orthogonally relative to said plurality of refrigerant carrying members and being disposed in generally parallel relationship. 
   
   
       3 . A refrigerated merchandiser as set forth in  claim 2  wherein said plurality of fins are spaced apart in the range of 0.4 to 0.8 inches between adjacent fins. 
   
   
       4 . A refrigerated merchandiser as set forth in  claim 2  wherein said plurality of fins are spaced apart at a spacing of at least 0.6 inches between adjacent fins. 
   
   
       5 . A refrigerated merchandiser as set forth in  claim 2  wherein said plurality of fins are spaced apart in the range of 0.7 to 0.8 inches between adjacent fins. 
   
   
       6 . A refrigerated merchandiser as set forth in  claim 2  wherein said plurality of fins are spaced apart substantially 0.75 inches between adjacent fins. 
   
   
       7 . A refrigerated merchandiser as recited in  claim 1  wherein said plurality of fins comprises a plurality of generally V-fins being spaced apart at a spacing of at least 0.4 inches between adjacent fins as measured from apex to apex. 
   
   
       8 . A refrigerated merchandiser as set forth in  claim 7  wherein said plurality of fins are spaced apart in the range of 0.4 to 0.8 inches between adjacent fins as measured from apex to apex. 
   
   
       9 . A refrigerated merchandiser as set forth in  claim 7  wherein said plurality of fins are spaced apart at a spacing of at least 0.6 inches between adjacent fins as measured from apex to apex. 
   
   
       10 . A refrigerated merchandiser as set forth in  claim 7  wherein said plurality of fins are spaced apart in the range of 0.7 to 0.8 inches between adjacent fins as measured from apex to apex. 
   
   
       11 . A refrigerated merchandiser as set forth in  claim 7  wherein said plurality of fins are spaced apart substantially 0.75 inches between adjacent fins as measured from apex to apex. 
   
   
       12 . A refrigerated merchandiser as set forth in  claim 1  wherein said plurality of refrigerant carrying members comprises a plurality of flat tubes aligned in generally parallel relationship, each tube having a plurality of longitudinally extending channels that are fluidly connected at a first end to receive refrigerant flow from an inlet header and at a second end to discharge refrigerant flow to an outlet header. 
   
   
       13 . A refrigerated merchandiser as set forth in  claim 12  wherein said flat tubes are spaced in the range of 0.4 to 0.8 inches between adjacent tubes. 
   
   
       14 . A refrigerated merchandiser as set forth in  claim 12  wherein said flat tubes are spaced in the range of 0.7 to 0.8 inches between adjacent tubes. 
   
   
       15 . A refrigerated merchandiser as set forth in  claim 12  wherein said flat tubes are spaced substantially 0.75 inches between adjacent tubes. 
   
   
       16 . A refrigerated merchandiser as set forth in  claim 1  wherein said plurality of refrigerant carrying members comprises a serpentine tube having a plurality of flat tube segments aligned in generally parallel relationship with adjacent tube members being interconnected at their respective ends to form a serpentine refrigerant flow path, the serpentine tube having a plurality of longitudinally extending channels that are fluidly connected at a first end to receive refrigerant flow from an inlet header and at a second end to discharge refrigerant flow to an outlet header. 
   
   
       17 . A refrigerated merchandiser as set forth in  claim 16  wherein said flat tube segments are spaced at a spacing of at least 0.6 inches between adjacent tube segments. 
   
   
       18 . A refrigerated merchandiser as set forth in  claim 16  wherein said flat tube segments are spaced in the range of 0.4 to 0.8 inches between adjacent tube segments. 
   
   
       19 . A refrigerated merchandiser as set forth in  claim 16  wherein said flat tube segments are spaced in the range of 0.7 to 0.8 inches between adjacent tube segments. 
   
   
       20 . A refrigerated merchandiser as set forth in  claim 1  wherein each of said plurality of refrigerant carrying members comprises a flat tube segments having a plurality of longitudinally extending channels defining flow passages, each channel having a hydraulic diameter of about 1 millimeter to about 2 millimeters. 
   
   
       21 . A refrigerated merchandiser comprising:
 an enclosure defining a refrigerated display cabinet and having an access opening for providing access to the refrigerated display cabinet;   an evaporator coil disposed in operative association with the refrigerated display cabinet; and   a condenser coil connected in refrigerant flow communication with said evaporator coil, said condenser coil having at least one serpentine shaped refrigerant carrying member having a plurality of flat segments aligned in generally parallel relationship, said plurality of flat segments being spaced apart at a spacing of at least 0.4 inches between adjacent flat segments.   
   
   
       22 . A refrigerated merchandiser as recited in  claim 21  wherein said flat tube segments are spaced apart at a spacing of at least 0.6 inches between adjacent flat segments. 
   
   
       23 . A refrigerated merchandiser as recited in  claim 21  wherein said flat tube segments are spaced apart at a spacing in the range of 0.4 to 0.8 inches between adjacent flat segments. 
   
   
       24 . A refrigerated merchandiser as recited in  claim 21  wherein said flat tube segments are spaced apart at a spacing in the range of 0.7 to 0.8 inches between adjacent flat segments. 
   
   
       25 . A refrigerated merchandiser as recited in  claim 21  wherein each of said flat tube segments has a plurality of longitudinally extending channels providing a corresponding plurality of refrigerant flow passages. 
   
   
       26 . A refrigerated merchandiser as recited in  claim 25  wherein each of said channels has a hydraulic diameter in the range from about 200 microns to about 5 millimeters. 
   
   
       27 . A refrigerated merchandiser comprising:
 an enclosure defining a refrigerated display cabinet and having an access opening for providing access to the refrigerated display cabinet;   an evaporator coil disposed in operative association with the refrigerated display cabinet; and   a condenser coil connected in refrigerant flow communication with said evaporator coil, said condenser coil having a plurality of refrigerant carrying members aligned in generally parallel relationship and a plurality of generally V-shaped fins connected in heat transfer relationship with and extending between adjacent members of said plurality of refrigerant carrying members, said plurality of generally V-shaped fins being spaced apart at a spacing of at least 0.25 inches between adjacent fins.   
   
   
       28 . A refrigerated merchandiser as set forth in  claim 27  wherein said plurality of fins are spaced apart in the range of about 0.4 to about 0.8 inches between adjacent fins as measured from apex to apex. 
   
   
       29 . A refrigerated merchandiser as set forth in  claim 27  wherein said plurality of fins are spaced apart at a spacing of about ⅓ to about ½ inches between adjacent fins as measured from apex to apex. 
   
   
       30 . A refrigerated merchandiser as set forth in  claim 27  wherein said plurality of refrigerant carrying members comprises a plurality of flat tubes aligned in generally parallel relationship, each tube having a plurality of longitudinally extending channels that are fluidly connected at a first end to receive refrigerant flow from an inlet header and at a second end to discharge refrigerant flow to an outlet header. 
   
   
       31 . A refrigerated merchandiser as set forth in  claim 30  wherein said flat tubes are spaced in the range of 0.4 to 0.8 inches between adjacent tubes. 
   
   
       32 . A refrigerated merchandiser as set forth in  claim 30  wherein said flat tubes are spaced in the range of 0.7 to 0.8 inches between adjacent tubes. 
   
   
       33 . A refrigerated merchandiser as set forth in  claim 30  wherein said flat tubes are spaced substantially 0.75 inches between adjacent tubes. 
   
   
       34 . A refrigerated merchandiser as set forth in  claim 27  wherein said plurality of refrigerant carrying members comprises a serpentine tube having a plurality of flat tube segments aligned in generally parallel relationship with adjacent tube members being interconnected at their respective ends to form a serpentine refrigerant flow path, the serpentine tube having a plurality of longitudinally extending channels that are fluidly connected at a first end to receive refrigerant flow from an inlet header and at a second end to discharge refrigerant flow to an outlet header. 
   
   
       35 . A refrigerated merchandiser as set forth in  claim 34  wherein said flat tube segments are spaced at a spacing of at least 0.6 inches between adjacent tube segments. 
   
   
       36 . A refrigerated merchandiser as set forth in  claim 34  wherein said flat tube segments are spaced in the range of 0.4 to 0.8 inches between adjacent tube segments. 
   
   
       37 . A refrigerated merchandiser as set forth in  claim 34  wherein said flat tube segments are spaced in the range of 0.7 to 0.8 inches between adjacent tube segments. 
   
   
       38 . A refrigerated merchandiser as set forth in  claim 27  wherein each of said plurality of refrigerant carrying members comprises a flat tube segments having a plurality of longitudinally extending channels defining flow passages, each channel having a hydraulic diameter of about 1 millimeter to about 2 millimeters. 
   
   
       39 . A refrigerated merchandiser as recited in  claim 38  wherein each of said channels has a hydraulic diameter in the range from about 200 microns to about 5 millimeters. 
   
   
       40 . A refrigerated merchandiser comprising:
 an enclosure defining a refrigerated display cabinet and having an access opening for providing access to the refrigerated display cabinet;   an evaporator coil disposed in operative association with the refrigerated display cabinet; and   a condenser coil connected in refrigerant flow communication with said evaporator coil, said condenser coil having a plurality of refrigerant carrying members aligned in generally parallel relationship and a plurality of fins connected in heat transfer relationship with and extending between adjacent members of said plurality of refrigerant carrying members, said plurality of fins being arranged in a zig-zag pattern and spaced apart at a spacing in the range of from ⅓ inches to ½ inches apex to apex.