Heat exchanger

Abstract

A heat exchanger is formed with tessellating conduits 4 passing therethrough. The tessellating conduits having transverse cross-sectional shapes which together substantially completely cover the transverse plane to the heat exchange 2 . The tessellating conduits may be the outer conduits 18 within conduit pairs formed of an outer conduit 18 and an inner conduit 22 . The outer conduits may have a cross-section that is a regular hexagon and the inner conduits may have a cross-section that is a circle. The heat exchanger can advantageously be formed by selective remelting of material with an energy beam.

1 . A heat exchanger comprising:
 a body with a portion having a plurality of substantially parallel fluid carrying tessellating conduits passing therethrough, wherein   said tessellating conduits have transverse cross-sections with one or more shapes that substantially completely cover a plane through said portion of said body transverse to said tessellating conduits by repeated use of said one or more shapes.   
     
     
         2 . A heat exchanger as claimed in  claim 1 , wherein said tessellating conduits have transverse cross-sections with one shape that regularly tessellates to cover said plane. 
     
     
         3 . A heat exchanger as claimed in  claim 2 , wherein said tessellating conduits have regular hexagonal transverse cross-sections. 
     
     
         4 . A heat exchanger as claimed in  claim 1 , wherein said tessellating conduits are outer conduits of respective conduit pairs, each conduit pair being an outer conduit and an inner conduit disposed within said outer conduit over at least a part of said outer conduit. 
     
     
         5 . A heat exchanger as claimed in  claim 4 , wherein said outer conduit and said inner conduit within a conduit pair are connected to receive respective different fluids. 
     
     
         6 . A heat exchanger as claimed in  claim 4 , wherein said inner conduits have a substantially circular transverse cross-section. 
     
     
         7 . A heat exchanger as claimed in  claim 4 , wherein within a conduit pair a plurality of arms extend from said inner conduit to said outer conduit to hold said inner conduit in position. 
     
     
         8 . A heat exchanger as claimed in  claim 1 , wherein said tessellating conduits are arranged in concentric rings with tessellating conduits in adjacent rings being connected to receive respective different fluids. 
     
     
         9 . A heat exchanger as claimed in  claim 1 , wherein neighbouring tessellating conduits have polygonal transverse cross-sections and walls between neighbouring tessellating conduits are shared such that all walls of a tessellating conduit completely surrounded by neighbouring tessellating conduits are shared walls. 
     
     
         10 . A heat exchanger as claimed in  claim 1 , wherein an edge conduit being a tessellating conduit not completely surrounded by other tessellating conduits has a transverse cross-section differing from said one or more shapes. 
     
     
         11 . A heat exchanger as claimed in  claim 10 , wherein said edge conduit has at least one wall shared with a neighbouring tessellating conduit and at least one wall not shared with a neighbouring tessellating conduit and thicker than said at least one wall shared with a neighbouring tessellating conduit. 
     
     
         12 . A heat exchanger as claimed in  claim 1 , wherein conduit walls of said tessellating conduits thicken proximal to vertices of said one or more shapes. 
     
     
         13 . A heat exchanger as claimed in  claim 12 , wherein said conduit walls are curved at said vertices. 
     
     
         14 . A heat exchanger as claimed in  claim 1 , wherein said body is formed of remelted material being layers of material remelted with an energy beam to form part of said body prior to addition of a successive layer. 
     
     
         15 . A heat exchanger as claimed in  claim 1 , comprising one or more fluid manifolds connected to said tessellating conduits, said one or more fluid manifolds being formed of remelted material being layers of material remelted with an energy beam to form part of said manifold prior to addition of a successive layer. 
     
     
         16 . A heat exchanger as claimed in  claim 1 , wherein said heat exchanger has surface area to volume ratio of greater than one of:
 5000 m 2 /m 3 ;   10000 m 2 /m 3 ; and   15000 m 2 /m 3 .   
     
     
         17 . A method of making at least a portion of a heat exchanger, said portion having a plurality of tessellating conduits passing therethrough, said method comprising the steps of:
 providing a plurality of successive layers of a material to be remelted; and   energy beam remelting predetermined regions of each layer in accordance with a predetermined design, said energy beam remelting of each layer being performed prior to addition of a successive layer;   wherein said predetermined regions of each layer subjected to energy beam remelting form solid structures within said layer and said energy beam remelting of each layer fuses said predetermined regions of each layer to remelted regions of a preceding layer; and   said tessellating conduits have transverse cross-sections with one or more shapes that substantially completely cover a plane through said portion of said body transverse to said tessellating conduits by repeated use of said one or more shapes.