Condenser and tube therefor

Abstract

Disclosed is a condenser and especially a tube therefor which is particularly suited for use in condensers that operate at operating pressures of approximately 20 bar. The condenser is a flat-tube condenser having tubes of substantially flat cross section extending between header tubes and cooling fins supported on the flat surfaces of the tubes. The tubes have a substantially flat cross section and a plurality of flow channels disposed side by side. The flow channels are substantially circular and have a hydraulic diameter of from 1.10 mm to 1.30 mm. Tubes of flat cross section and circular flow channels disposed in series operate with a particular advantageous effect in serpentine condensers.

1 . A tube for a condenser operating under pressures of approximately 20 bar, comprising: 
 a) a cross section having a width that is greater than its height;    b) a substantially flat profile along a width of the tube; and    c) a plurality of flow channels arranged side by side along a width of the tube, wherein the flow channels comprise a substantially round cross section and further comprise a hydraulic diameter of 1.10 to 1.30 mm.    
   
   
       2 . A tube as claimed in  claim 1 , further comprising a continuous web arranged between the flow channels and separating adjacent flow channels from one another.  
   
   
       3 . A tube as claimed in  claim 2 , wherein the tube comprises flow channels disposed side by side in a widthwise direction.  
   
   
       4 . A tube as claimed in  claim 3 , wherein the flow channels comprise a hydraulic diameter of from 1.14 mm to 1.26 mm.  
   
   
       5 . A tube as claimed in  claim 3 , wherein the flow channels comprise a hydraulic diameter of from 1.18 mm to 1.22 mm.  
   
   
       6 . A tube as claimed in  claim 3 , wherein the flow channels comprise a hydraulic diameter of about 1.20 mm.  
   
   
       7 . A tube as claimed in  claim 6 , wherein the cross section of the tube comprises a width of about 16 mm, a height of about 1.8 mm, a minimum thickness, W, of a wall between the flow channels and of an outer wall of the tube of approximately 0.3 mm and a minimum thickness, S, of the webs between the flow channels of approximately 0.2 mm.  
   
   
       8 . A tube as claimed in  claim 1 , further comprising 11 parallel flow channels in a row.  
   
   
       9 . A condenser operating under pressures of approximately 20 bar comprising at least one tube as claimed in  claim 1 .  
   
   
       10 . A condenser as claimed in  claim 9 , further comprising a plurality of said tubes; two header tubes arranged in leak-proof fluid communication with each of the plurality of tubes; and cooling fins arranged between adjacent tubes of the plurality of tubes.  
   
   
       11 . A condenser as claimed in  claim 10 , or wherein the header tubes each comprise a substantially circular cross section, a plurality of apertures, each receiving one of the plurality of tubes to provide fluid communication between a header and one of said tubes, and a fixed connection between each header and the plurality of tubes received thereby.  
   
   
       12 . A condenser as claimed in  claim 10 , further comprising a refrigerant inlet line in fluid communication with one header and a refrigerant outlet line in fluid communication with one header.  
   
   
       13 . A condenser as claimed in  claim 12 , wherein the refrigerant inlet is connected to a first header tube substantially at a first end and the refrigerant outlet is connected to a second header tube substantially at a second end wherein the second end is remote from the end of the second header tube lying opposite the first end of the first header tube.  
   
   
       14 . A condenser as claimed in  claim 12 , wherein the refrigerant inlet is connected to a first header tube at one end and the refrigerant outlet is connected to the other end of the first header tube.  
   
   
       15 . A condenser as claimed in  claim 10 , wherein the header tubes and the plurality of tubes are formed and arranged such that refrigerant entering said condenser passes through a first set of tubes from the first header tube to the second header tube and is then guided back through a second set of tubes from the second header tube to the first header tube.  
   
   
       16 . A condenser as claimed in  claim 15 , further comprising at least n partitions in the second header tube for directing refrigerant flowing therethrough through a set of tubes to the first header tube downstream of the last tube of that set and n-1 further partitions provided in the first header tube for each return of the refrigerant through a further set of tubes to the second header tube downstream of the last tube of this further set, wherein n=1 or 2.  
   
   
       17 . A condenser as claimed in  claim 15 , wherein the number of tubes of each set of tubes is greater than or equal to the number of tubes in a further set of tubes arranged adjacently downstream.  
   
   
       18 . A condenser as claimed in  claim 15 , comprising 6 sets of tubes wherein a first set, which leads away from the refrigerant inlet, comprises 17 tubes, a second set downstream of and adjacent to the first set comprises 10 tubes, a third set downstream of and adjacent to the second set comprises 7 tubes, a fourth set downstream of and adjacent to the third set comprises 6 tubes, a fifth set downstream of and adjacent to a fourth set comprising 4 tubes and a sixth set downstream of and adjacent to the fifth set comprising 4 tubes.  
   
   
       19 . A condenser as claimed in  claim 10 , wherein the refrigerant inlet is suitable for the admission of, refrigerant substantially in vapor form, wherein the header tubes and the tubes are suitable for the condensation of refrigerant vapor and wherein the refrigerant outlet is suitable for the release of, refrigerant substantially in condensed form.  
   
   
       20 . A method of producing a tube as claimed in  claim 1 , comprising extruding the tube.  
   
   
       21 . A method as claimed in  claim 20 , further comprising extruding the tube from aluminum or an alloy thereof.  
   
   
       22 . A motor vehicle comprising a condenser as claimed in  claim 9.