Steam generator and method of securing tubes within a steam generator against vibration

Abstract

A steam generator includes a tube bundle having a plurality of tubes, arranged in rows and columns. The first column of tubes includes a first tube having a curved center line disposed in a first plane. The second column of tubes includes a second tube having a curved center line disposed in a second plane, the second plane being parallel to and spaced a distance from the first plane. The steam generator further includes a first number of solid anti-vibration bars disposed between the first column of tubes and the second column of tubes; wherein each of the tubes has a tube outer diameter; and wherein each of the first number of anti-vibration bars has a thickness generally transverse to the first and second planes, the thickness being greater than the distance between the first and second planes minus the tube outer diameter.

What is claimed is: 
     
         1 . A steam generator having a primary side for circulating a heated fluid and a secondary side for circulating a fluid to be heated by the heated fluid circulating in the primary side, the steam generator comprising:
 a channel head for receiving the heated fluid;   a tube sheet that separates the channel head from the secondary side;   a tube bundle having a plurality of tubes, arranged in rows and columns, the tube bundle extending from the channel head, through the tube sheet and through at least a portion of the secondary side; and   a first number of solid anti-vibration bars;   wherein the plurality of tubes comprises:
 a first column of tubes, the first column of tubes comprising a first tube having a curved center line disposed in a first plane, and 
 a second column of tubes, each of the first number of anti-vibration bars being disposed between the first column of tubes and the second column of tubes, the second column of tubes comprising a second tube having a curved center line disposed in a second plane, the second plane being parallel to and spaced a distance from the first plane, 
   wherein each of the tubes has a tube outer diameter;   wherein each of the first number of anti-vibration bars has a thickness generally transverse to the first and second planes; and   wherein the thickness of each of the first number of anti-vibration bars is greater than the distance between the first and second planes minus the tube outer diameter.   
     
     
         2 . The steam generator of  claim 1  wherein each of the first number of anti-vibration bars comprises a number of bends; wherein the bends of each of the first number of anti-vibration bars wind between the first column of tubes and the second column of tubes; and wherein the bends of each of the first number of anti-vibration bars are curved. 
     
     
         3 . The steam generator of  claim 1  wherein each of the first number of anti-vibration bars comprises a number of bends; wherein the bends of each of the first number of anti-vibration bars wind between the first column of tubes and the second column of tubes; and wherein the bends of each of the first number of anti-vibration bars are substantially jagged. 
     
     
         4 . The steam generator of  claim 1  further comprising a second number of solid anti-vibration bars;
 wherein the plurality of tubes further comprises a third column of tubes; 
 wherein each of the second number of anti-vibration bars is disposed between the second column of tubes and the third column of tubes; 
 wherein the third column of tubes comprises a third tube having a curved center line disposed in a third plane; 
 wherein the third plane is parallel to and spaced a distance from the second plane; 
 wherein each of the second number of anti-vibration bars has a thickness generally transverse to the second and third planes; and 
 wherein the thickness of each of the second number of anti-vibration bars is greater than the distance between the second and third planes minus the tube outer diameter. 
 
     
     
         5 . The steam generator of  claim 4  wherein the plurality of tubes have a triangular pitch; wherein the tube bundle comprises a U-shaped bend; and wherein each of the first number of anti-vibration bars and the second number of anti-vibration bars is disposed in the U-shaped bend. 
     
     
         6 . The steam generator of  claim 4  wherein the plurality of tubes have a rotated square pitch; wherein the tube bundle comprises a U-shaped bend; and wherein each of the first number of anti-vibration bars and the second number of anti-vibration bars is disposed in the U-shaped bend. 
     
     
         7 . The steam generator of  claim 4  wherein each of the first number of anti-vibration bars and the second number of anti-vibration bars comprises a number of bends; wherein the bends of each of the first number of anti-vibration bars wind between the first column of tubes and the second column of tubes; and wherein the bends of each of the second number of anti-vibration bars wind between the second column of tubes and the third column of tubes. 
     
     
         8 . The steam generator of  claim 1  further comprising a second number of anti-vibration bars;
 wherein the plurality of tubes further comprises a third column of tubes; 
 wherein each of the second number of anti-vibration bars is disposed between the second column of tubes and the third column of tubes; 
 wherein the third column of tubes comprises a third tube having a curved center line disposed in a third plane; 
 wherein the third plane is parallel to and spaced a distance from the second plane; 
 wherein each of the second number of anti-vibration bars has a thickness generally transverse to the second and third planes; and 
 wherein the thickness of each of the second number of anti-vibration bars is less than the thickness of each of the first number of anti-vibration bars. 
 
     
     
         9 . The steam generator of  claim 8  wherein the thickness of each of the second number of anti-vibration bars is substantially equal to the distance between the second and third planes minus the tube outer diameter. 
     
     
         10 . A method of securing tubes within a steam generator against vibration, the tubes being disposed in a tube bundle and arranged in rows and columns, with lanes between the columns, the method comprising:
 providing a first column of tubes, the first column of tubes comprising a first tube having a curved center line disposed in a first plane;   providing a first number of solid anti-vibration bars; and   providing a second column of tubes, each of the first number of anti-vibration bars being disposed between the first column of tubes and the second column of tubes, the second column of tubes comprising a second tube having a curved center line disposed in a second plane, the second plane being parallel to and spaced a distance from the first plane;   wherein each of the tubes has a tube outer diameter;   wherein each of the first number of anti-vibration bars has a thickness generally transverse to the first and second planes; and   wherein the thickness of each of the first number of anti-vibration bars is greater than the distance between the first and second planes minus the tube outer diameter.   
     
     
         11 . The method of  claim 10  wherein each of the first number of anti-vibration bars comprises a number of bends; wherein the bends of each of the first number of anti-vibration bars wind between the first column of tubes and the second column of tubes; and wherein the bends of each of the first number of anti-vibration bars are curved. 
     
     
         12 . The method of  claim 10  wherein each of the first number of anti-vibration bars comprises a number of bends; wherein the bends of each of the first number of anti-vibration bars wind between the first column of tubes and the second column of tubes; and wherein the bends of each of the first number of anti-vibration bars are substantially jagged. 
     
     
         13 . The method of  claim 10  further comprising:
 providing a second number of solid anti-vibration bars; and 
 providing a third column of tubes, each of the second number of anti-vibration bars being disposed between the second column of tubes and the third column of tubes, the third column of tubes comprising a third tube having a curved center line disposed in a third plane, the third plane being parallel to and spaced a distance from the second plane; 
 wherein each of the second number of anti-vibration bars has a thickness generally transverse to the second and third planes; and 
 wherein the thickness of each of the second number of anti-vibration bars is greater than the distance between the second plane and third planes minus the tube outer diameter. 
 
     
     
         14 . The method of  claim 13  wherein the first number of anti-vibration bars comprises a first anti-vibration bar substantially disposed along a first longitudinal axis; wherein the second number of anti-vibration bars comprises a second anti-vibration bar substantially disposed along a second longitudinal axis parallel to the first longitudinal axis; wherein the first anti-vibration bar is disposed adjacent the first tube and the second tube; wherein the second anti-vibration bar is disposed adjacent the second tube and the third tube; wherein there is a first gap between the first anti-vibration bar and the first tube and a second gap between the first anti-vibration bar and the second tube; and wherein there is a third gap between the second anti-vibration bar and the second tube and a fourth gap between the second anti-vibration bar and the third tube, the method further comprising:
 displacing the first anti-vibration bar in a first direction along the first longitudinal axis; and 
 displacing the second anti-vibration bar in a second direction along the second longitudinal axis, the second direction being opposite the first direction, each of the first gap, the second gap, the third gap, and the fourth gap having a size that decreases as the first anti-vibration bar is displaced in the first direction and the second anti-vibration bar is displaced in the second direction. 
 
     
     
         15 . The method of  claim 14  wherein the tubes have a triangular pitch; wherein the tube bundle comprises a U-shaped bend; and wherein each of the first number of anti-vibration bars and the second number of anti-vibration bars is disposed in the U-shaped bend. 
     
     
         16 . The method of  claim 14  wherein the tubes have a rotated square pitch; wherein the tube bundle comprises a U-shaped bend; and wherein each of the first number of anti-vibration bars and the second number of anti-vibration bars is disposed in the U-shaped bend. 
     
     
         17 . The method of  claim 14  wherein each of the first number of anti-vibration bars and the second number of anti-vibration bars comprises a number of bends; wherein the bends of each of the first number of anti-vibration bars wind between the first column of tubes and the second column of tubes; and wherein the bends of each of the second number of anti-vibration bars wind between the second column of tubes and the third column of tubes. 
     
     
         18 . The method of  claim 10  further comprising:
 providing a second number of anti-vibration bars; and 
 providing a third column of tubes, each of the second number of anti-vibration bars being disposed between the second column of tubes and the third column of tubes, the third column of tubes comprising a third tube having a curved center line disposed in a third plane, the third plane being parallel to and spaced a distance from the second plane; 
 wherein each of the second number of anti-vibration bars has a thickness generally transverse to the second and third planes; and 
 wherein the thickness of each of the second number of anti-vibration bars is less than the thickness of each of the first number of anti-vibration bars. 
 
     
     
         19 . The method of  claim 18  wherein the thickness of each of the second number of anti-vibration bars is substantially equal to the distance between the second and third planes minus the tube outer diameter. 
     
     
         20 . The method of  claim 19  wherein each of the second number of anti-vibration bars has no bend or curvature along a longitudinal axis.