Coil Wound Heat Exchanger Deformable Support System And Method

Abstract

A coil wound heat exchanger utilizing a deformable support system and method for making a tube bundle for the same includes a mandrel, a first tube layer formed by winding one or more tubes around the mandrel, and a plurality of supports and spacers circumferentially-arranged in an alternating pattern on an outer surface of the first tube layer. A second tube layer is formed by winding one or more tubes around the mandrel, whereby the second tube layer contacts an opposite side of the supports. A deforming force is applied to the second tube layer in a direction normal to the outer surface of each support, which causes the one or more tubes forming the second tube layer to deform the outer support surface of each support.

1 . A method of forming a tube bundle for a coil wound heat exchanger, wherein the tube bundle comprises multiple tube layers, each layer comprises at least one tube, and the method comprises:
 (a) providing a mandrel that extends along a mandrel longitudinal axis;   (b) forming a first tube layer by winding at least one of the at least one tubes around the mandrel, the at least one tube having a tube height H;   (c) placing a plurality of first layer supports and a plurality of first layer spacers on an outer tube surface of the first tube layer, each of the first layer supports having a support longitudinal axis, an inner support surface that is in contact with the outer tube surface and an outer surface that is distal to the inner support surface, each of the plurality of first layer spacers having a spacer height S;   (d) forming a second tube layer by winding at least one of the at least one tubes around the mandrel, the first tube layer, and the plurality of first layer supports; and   (e) applying at least one deforming force to the second tube layer in a direction normal to the outer support surface of each of the plurality of first layer supports sufficient to cause the at least one tube forming the second tube layer to deform at least one of the outer support surface and the inner support surface of each of the plurality of first layer supports without deforming the at least one tube forming the second tube layer.   
     
     
         2 . The method of  claim 1 , wherein a radial layer spacing between the first tube layer and the second tube layer is greater than the spacer height S prior to performing step (e) and is equal to the spacer height S after performing step (e). 
     
     
         3 . The method of  claim 1 , further comprising:
 (f) placing a plurality of mandrel layer supports on the mandrel prior to performing step (b), so that the mandrel layer supports are positioned between the mandrel and the first tube layer.   
     
     
         4 . The method of  claim 1 , wherein the application of the deforming force moves at least one of the outer support surface or the inner support surface of at least one of the plurality of first layer supports from an initial contact position to a recessed position, and wherein the distance E between the initial contact position and the recessed position is at least 5% of the tube height H. 
     
     
         5 . The method of  claim 4 , wherein the distance E is less than 50% of the tube height H. 
     
     
         6 . The method of  claim 1 , wherein the deforming force of step (e) is a result of applying tension to the second tube layer during step (d). 
     
     
         7 . The method of  claim 1 , wherein at least a portion of the deforming force of step (e) is applied by an external device that is passed over the second tube layer during or after the performance of step (d). 
     
     
         8 . The method of  claim 1 , wherein step (b) further comprises winding the at least one first layer tube around the mandrel at a winding angle α relative to the mandrel longitudinal axis and step (d) further comprises winding the at least one second layer tube at a winding angle-a relative to the mandrel longitudinal axis. 
     
     
         9 . The method of  claim 1 , wherein each of the at least one tubes has a tube radial crush strength and each of the plurality of first layer supports has a support outer layer having a support outer layer radial crush strength that is less than the tube radial crush strength. 
     
     
         10 . The method of  claim 8 , wherein the outer support surface of each support of the plurality of first layer supports is adapted to deform via the deforming force to create a tube seat oriented at an angle corresponding to either of the winding angle α or the winding angle-a during the performance of step (b). 
     
     
         11 . The method of  claim 1 , wherein each of the plurality of first layer supports comprises a non-deformable spacer portion that does not substantially deform during the performance of step (e). 
     
     
         12 . The method of  claim 1 , wherein step (b) further comprises arranging the plurality of first layer supports and the plurality of first layer spacers in a circumferentially-alternating arrangement on the outer tube surface of the first tube layer. 
     
     
         13 . The method of  claim 1 , further comprising:
 (g) prior to performing step (d), applying a pre-winding force to each of the plurality of first layer supports that results in a deformation of each of the plurality of first layer supports on only the inner support surface.   
     
     
         14 . The method of  claim 1 , further comprising forming one or more additional tube layers in the tube bundle by repeating steps (c) through (e) for each additional tube layer in the tube bundle. 
     
     
         15 . The method of  claim 1 , wherein each of the plurality of first layer supports placed in step (c) is also one of the plurality of first layer spacers. 
     
     
         16 . The method of  claim 15 , wherein each of the plurality of first layer supports comprises an inner layer and at least one outer layer, the inner layer having a maximum inner layer radial crush strength that is greater than an outer layer maximum radial crush strength of each of the at least one outer layers. 
     
     
         17 . A method of forming a tube bundle for a coil wound heat exchanger, wherein the tube bundle comprises multiple tube layers, each layer comprises at least one tube, and the method comprises:
 (a) providing a mandrel that extends along a mandrel longitudinal axis;   (b) forming a first tube layer by winding at least one of the at least one tubes around the mandrel, the at least one tube having a tube height H;   (c) placing a plurality of first layer supports and a plurality of first layer spacers on an outer tube surface of the first tube layer in a circumferentially-alternating arrangement, each of the plurality of first layer supports having an undeformed support height H 2  and each of the plurality of first layer spacers having a spacer height H 1 ;   (d) forming a second tube layer by winding at least one of the at least one tubes around the mandrel, the first tube layer, and the plurality of first layer supports; and   (e) applying at least one deforming force to the second tube layer sufficient to deform each of the plurality of first layer supports without deforming the at least one tube forming the second tube layer;   wherein the first and second tube layers have an initial layer spacing at each of the plurality of first layer supports prior to performing step (e) and a final layer spacing at each of the plurality of first layer supports after performing step (e), the final layer spacing being less than the initial layer spacing.   
     
     
         18 . The method of  claim 17 , wherein each support of the plurality of first layer supports comprises a plurality of separate support structures, such that each support of the plurality of first layer supports is discontinuous along the axial direction of the tube bundle. 
     
     
         19 . The method of  claim 17 , wherein the final layer spacing is substantially equal to the spacer height H 1 . 
     
     
         20 . The method of  claim 17 , wherein the initial layer spacing is substantially equal to the undeformed support height H 2 .