Multi-cross sectional fluid path condenser

Abstract

A refrigerant condenser having multiple sections of straight tubes terminating in segmented headers, each subsequent section having an overall cross-sectional area less than an initial section with the overall cross section of the initial section large enough to substantially reduce vapor velocity thus reducing the refrigerant pressure drop; the total cross-sectional area dimensioned to cause entrance vapor velocity, to be sufficient to establish an internal film heat transfer coefficient greater than the external heat transfer coefficient while limiting the internal pressure drop for the heat rejection intended.

1 . A heat exchange bundle for a refrigerant condenser comprising:
 a first condenser section comprising a first set of straight refrigerant passages having a first total cross-sectional area;   a second condenser section comprising a second set of straight refrigerant passages having a second total cross-sectional area;   an inlet header;   a first intermediate header;   said first set of straight refrigerant passages each connected at a first end to said inlet header and connected at a second end to said intermediate header;   said second set of straight refrigerant passages each connected at a first end to said intermediate header;   said second total cross-sectional area less than said first total cross-sectional area.   
     
     
         2 . A heat exchange bundle for a refrigerant condenser according to  claim 1 , further comprising:
 an outlet header;   said second set of straight refrigerant passages each connected at a second end to said outlet header.   
     
     
         3 . A heat exchange bundle for a refrigerant condenser according to  claim 1 , further comprising
 a third condenser section comprising a third set of straight refrigerant passages having a third total cross-sectional area;   a second intermediate header;   said second set of straight refrigerant passages each connected at a second end to said second intermediate header;   said third set of straight refrigerant passages each connected at a first end to said second intermediate header;   said third total cross-sectional area less than said second total cross-sectional area.   
     
     
         4 . A heat exchange bundle for a refrigerant condenser according to  claim 3 , further comprising:
 an outlet header;   said third set of straight refrigerant passages each connected at a second end to said outlet header.   
     
     
         5 . A heat exchange bundle for a refrigerant condenser according to  claim 3 , further comprising
 a fourth condenser section comprising a fourth set of straight refrigerant passages having a fourth total cross-sectional area;   a third intermediate header;   said third set of straight refrigerant passages each connected at a second end to said third intermediate header;   said fourth set of straight refrigerant passages each connected at a first end to said third intermediate header;   said fourth total cross-sectional area less than said second total cross-sectional area.   
     
     
         6 . A heat exchange bundle for a refrigerant condenser according to  claim 5 , further comprising:
 an outlet header;   said fourth set of straight refrigerant passages each connected at a second end to said outlet header.   
     
     
         7 . A heat exchange bundle for a refrigerant condenser according to  claim 1 , wherein said first condenser section and said second condenser section have an identical number of refrigerant passages, and a cross-sectional area of each refrigerant passage in said second condenser section is less than a cross-sectional area of each refrigerant passage in said first condenser section. 
     
     
         8 . A heat exchange bundle for a refrigerant condenser according to  claim 1 , wherein a cross-sectional area of each refrigerant passage in said second condenser section is less than a cross-sectional area of each refrigerant passage in said first condenser section, and a number of refrigerant passages in said first condenser section and said second condenser section is the same. 
     
     
         9 . A heat exchange bundle for a refrigerant condenser according to  claim 1 , wherein a cross-sectional area of each refrigerant passage in said second condenser section is less than a cross-sectional area of each refrigerant passage in said first condenser section, and said second condenser section has fewer refrigerant passages than said first condenser section. 
     
     
         10 . An evaporative refrigerant condenser comprising:
 a housing defining an indirect heat exchange section situated above a plenum section;   a fan situated on top of said housing and configured to draw ambient air said plenum section through openings at a bottom of said housing, through said coil section and out through a top of said housing through said fan;   a water distribution assembly located in said housing and above said coil section for selectively distributing water over said coil section;   a water collection section located at a bottom of said housing for collecting water distributed by said water distribution assembly;   a water pump for pumping water from said water collection section to said water distribution assembly;   a heat exchange located in said indirect heat exchange section, said heat exchange assembly comprising a heat exchange bundle according to  claim 1 .   
     
     
         11 . A method of improving the heat exchange efficiency for an evaporative refrigerant condenser having a housing defining an indirect heat exchange section situated above a plenum section;
 a fan situated on top of said housing and configured to draw ambient air said plenum section through openings at a bottom of said housing, through said coil section and out through a top of said housing through said fan;   a water distribution assembly located in said housing and above said coil section for selectively distributing water over said coil section;   a water collection section located at a bottom of said housing for collecting water distributed by said water distribution assembly;   a water pump for pumping water from said water collection section to said water distribution assembly;   a first coil assembly located in said indirect heat exchange section, said coil assembly comprising a plurality single serpentine heat exchange tubes tightly packed adjacent to one-another;   each serpentine heat exchange tubes connected at a first end to an one inlet header and connected at a second end to an outlet header,   said method comprising replacing said first coil assembly with a heat exchange bundle according to  claim 1 .   
     
     
         12 . A method of improving the heat exchange efficiency for an evaporative refrigerant condenser comprising reducing the total cross-sectional area of a second condenser section as compared to a first condenser section sufficient to establish an internal film heat transfer coefficient greater than the external heat transfer coefficient. 
     
     
         13 . A method according to  claim 12 , comprising reducing the total cross-sectional area of successive condenser sections sufficient to maintain an internal film heat transfer coefficient greater than the external heat transfer coefficient. 
     
     
         14 . A heat exchange bundle according to  claim 1 , wherein said straight refrigerant passages are selected from the group consisting of oval tubes, round tubes, elliptical tubes and microchannel plates. 
     
     
         15 . A heat exchange bundle for a refrigerant condenser comprising:
 a first condenser section comprising first and second sets of straight refrigerant passages having a first total cross-sectional area and connected at one end by a set of first condenser section set of U-bends;   a second condenser section comprising third and fourth set of straight refrigerant passages having a second total cross-sectional area and connected at one end by set of second condenser section set of U-bends;   an inlet header;   a first intermediate header;   said first and second sets of straight refrigerant passages each connected at a first end to said inlet header and connected at a second end to said intermediate header;   said third and fourth sets of straight refrigerant passages each connected at a first end to said intermediate header and connected at a second end to a outlet header;   said second total cross-sectional area less than said first total cross-sectional area.   
     
     
         16 . A heat exchange bundle for a refrigerant condenser comprising:
 a first condenser section comprising a first set of refrigerant passages having a first total cross-sectional area;   a second condenser section comprising a second set of refrigerant passages having a second total cross-sectional area;   an inlet header;   a first intermediate header;   said first set of refrigerant passages each connected at a first end to said inlet header and connected at a second end to said intermediate header;   said second set of straight passages each connected at a first end to said intermediate header;   said second total cross-sectional area less than said first total cross-sectional area.   
     
     
         17 . A heat exchange bundle for a refrigerant condenser according to  claim 16 , further comprising:
 an outlet header;   said second set of refrigerant passages each connected at a second end to said outlet header.   
     
     
         18 . A heat exchange bundle for a refrigerant condenser according to  claim 16 , further comprising
 a third condenser section comprising a third set of refrigerant passages having a third total cross-sectional area;   a second intermediate header;   said second set of refrigerant passages each connected at a second end to said second intermediate header;   said third set of refrigerant passages each connected at a first end to said second intermediate header;   said third total cross-sectional area less than said second total cross-sectional area.   
     
     
         19 . A heat exchange bundle for a refrigerant condenser according to  claim 18 , further comprising:
 an outlet header;   said third set of refrigerant passages each connected at a second end to said outlet header.   
     
     
         20 . A heat exchange bundle for a refrigerant condenser according to  claim 18 , further comprising
 a fourth condenser section comprising a fourth set of refrigerant passages having a fourth total cross-sectional area;   a third intermediate header;   said third set of refrigerant passages each connected at a second end to said third intermediate header;   said fourth set of refrigerant passages each connected at a first end to said third intermediate header;   said fourth total cross-sectional area less than said third total cross-sectional area.   
     
     
         21 . A heat exchange bundle for a refrigerant condenser according to  claim 20 , further comprising:
 an outlet header;   said fourth set of refrigerant passages each connected at a second end to said outlet header.   
     
     
         22 . A heat exchange bundle for a refrigerant condenser according to  claim 16 , wherein said first condenser section and said second condenser section have an identical number of refrigerant passages, and a cross-sectional area of each refrigerant passage in said second condenser section is less than a cross-sectional area of each refrigerant passage in said first condenser section. 
     
     
         23 . A heat exchange bundle for a refrigerant condenser according to  claim 16 , wherein a cross-sectional area of each refrigerant passage in said second condenser section is less than a cross-sectional area of each refrigerant passage in said first condenser section, and a number of refrigerant passages in said first condenser section and said second condenser section is the same. 
     
     
         24 . A heat exchange bundle for a refrigerant condenser according to  claim 16 , wherein a cross-sectional area of each refrigerant passage in said second condenser section is less than a cross-sectional area of each refrigerant passage in said first condenser section, and said second condenser section has fewer refrigerant passages than said first condenser section.