Heat exchanger

Abstract

The heat exchanger uses multi-layer tubes, performing efficient heat exchange. Each heat transfer tube includes an outer tube and an inner tube. Header unit directs first fluid through gaps between the inner tube and the outer tube from outer circumferences of the inner tube. The header units are stacked in a top-bottom direction with gap-forming members therebetween, leaving predetermined gap portion. Furthermore, a header cover directs the second fluid through the inner tubes extending from the header units, and is fitted from the outer side, and the second fluid is introduced. With this configuration, the second fluid flowing from the header cover is directed through the inside of the inner tubes and over outer surfaces of the outer tubes along the axial direction via the gap portions, enabling heat exchange to be performed from both inside and outside of the outer tubes.

1 . A heat exchanger using heat transfer tubes each including an outer tube and an inner tube, the heat exchanger performing heat exchange between first fluid flowing through a gap between the outer tube and the inner tube and second fluid flowing through the inner tube, the heat exchanger comprising:
 header units that direct the first fluid through the gaps between the inner tubes and the outer tubes from the outer circumferences of the inner tubes, the ends of the inner tubes extending from the outer tubes;   second headers that direct second fluid through the inner tubes extending from the header units; and   gap portions provided between the stacked header units, through which the second fluid from the second headers flows,   wherein the second fluid from the second headers is directed through the inside of the inner tubes and over outer surfaces of the outer tubes along the axial direction via the gap portions.   
     
     
         2 . A heat exchanger using heat transfer tubes each including an outer tube and an inner tube, the heat exchanger performing heat exchange between first fluid flowing through a gap between the outer tube and the inner tube and second fluid flowing through the inner tube, the heat exchanger comprising:
 header units each holding portions near ends of the outer tubes at a first wall and allowing the inner tubes, which extend from the outer tubes, to extend through a second wall facing the first wall, the header units directing the first fluid through the gaps between the inner tubes and the outer tubes from a space enclosed by the first wall and the second wall;   second headers that direct the second fluid through the inner tubes extending from the second walls of the header units; and   gap portions provided between the stacked header units, through which the second fluid from the second headers flows,   wherein the second fluid from the second headers is directed through the inside of the inner tubes and over outer surfaces of the outer tubes along the axial direction via the gap portions.   
     
     
         3 . The heat exchanger according to  claim 1 ,
 wherein the gap portions are provided by disposing gap-forming members between the stacked header units.   
     
     
         4 . The heat exchanger according to  claim 1 ,
 wherein the gap portions are formed by projections or recesses that are formed as an integral part of the header units.   
     
     
         5 . The heat exchanger according to  claim 1 ,
 wherein splitting members that split and direct the second fluid flowing from the gap portions toward the heat transfer tubes are provided between the heat transfer tubes of the header units.   
     
     
         6 . The heat exchanger according to  claim 1 ,
 wherein splitting members that are in contact with the heat transfer tubes and split and direct the second fluid flowing from the gap portions toward the heat transfer tubes are provided between the heat transfer tubes of the header units.   
     
     
         7 . The heat exchanger according to  claim 2 ,
 wherein the gap portions are provided by disposing gap-forming members between the stacked header units.   
     
     
         8 . The heat exchanger according to  claim 2 ,
 wherein the gap portions are formed by projections or recesses that are formed as an integral part of the header units.   
     
     
         9 . The heat exchanger according to  claim 2 ,
 wherein splitting members that split and direct the second fluid flowing from the gap portions toward the heat transfer tubes are provided between the heat transfer tubes of the header units.   
     
     
         10 . The heat exchanger according to  claim 2 ,
 wherein splitting members that are in contact with the heat transfer tubes and split and direct the second fluid flowing from the gap portions toward the heat transfer tubes are provided between the heat transfer tubes of the header units.