Indirect Heat Exchanger Pressure Vessel with Controlled Wrinkle Bends

Abstract

In one aspect of the present disclosure, an indirect heat exchanger pressure vessel is provided that includes an inlet header to receive a pressurized working fluid, such as water, glycol, ammonia, and/or CO 2 . The indirect heat exchanger pressure vessel includes an outlet header to collect the pressurized working fluid and a serpentine circuit tube connecting the inlet and outlet headers. The serpentine circuit tube permits the pressurized working fluid to flow from the inlet header to the outlet header. The serpentine circuit tube includes runs and a return bend connecting the runs. The return bend has a controlled wrinkled portion comprising alternating ridges and grooves. The alternating ridges and grooves strengthen the return bend and permit the indirect heat exchanger pressure vessel to facilitate working fluid heat transfer at a high internal operating pressure.

1 - 28 . (canceled) 
     
     
         29 . An indirect heat exchanger pressure vessel comprising:
 an inlet header to receive a pressurized working fluid;   an outlet header to collect the pressurized working fluid;   a serpentine circuit tube connecting the inlet and outlet headers to permit flow of pressurized working fluid from the inlet header to the outlet header, the serpentine circuit tube including runs and a return bend connecting the runs;   the serpentine circuit tube having tangent points at junctures between the return bend and the runs, wherein the return bend comprises:
 a bend angle; 
 a controlled wrinkled portion; 
 the controlled wrinkled portion spaced from the tangent points along the serpentine circuit tube; and 
 wherein the controlled wrinkled portion has an angular extent about an inside of the return bend that is less than the bend angle. 
   
     
     
         30 . The indirect heat exchanger pressure vessel of  claim 29  wherein the controlled wrinkled portion of the return bend includes ridges and grooves; and
 wherein the ridges include end ridges spaced from the tangent points. 
 
     
     
         31 . The indirect heat exchanger pressure vessel of  claim 29  wherein the controlled wrinkled portion of the return bend includes end ridges spaced from the tangent points; and
 at least one of the end ridges including a tapered lead-in portion to smooth working fluid flow about the wrinkled portion. 
 
     
     
         32 . The indirect heat exchanger pressure vessel of  claim 31  wherein the end ridges both include a tapered lead-in portion to smooth working fluid flow about the wrinkled portion. 
     
     
         33 . The indirect heat exchanger pressure vessel of  claim 29  wherein the controlled wrinkled portion of the return bend includes alternating ridges and grooves, the ridges and grooves having amplitudes that vary about the return bend. 
     
     
         34 . The indirect heat exchanger pressure vessel of  claim 33  wherein the ridges and grooves include a first plurality of ridges and grooves that increase in amplitudes as the first plurality of ridges and grooves extend away from one of the tangent points about the return bend. 
     
     
         35 . The indirect heat exchanger pressure vessel of  claim 34  wherein the ridges and grooves include a second plurality of ridges and grooves intermediate the first plurality of ridges and grooves and the other tangent point; and
 wherein the second plurality of ridges and grooves decrease in amplitude as the second plurality of ridges and grooves extends away from the first plurality of ridges and grooves toward the other tangent point. 
 
     
     
         36 . The indirect heat exchanger pressure vessel of  claim 29  wherein the controlled wrinkled portion of the return bend has an angular extent about the inside of the return bend that is at least five degrees less than the return bend angle. 
     
     
         37 . The indirect heat exchanger pressure vessel of  claim 29  wherein the serpentine circuit tube has an outer diameter (OD) and a wall thickness (WT);
 wherein the return bend has a centerline radius and the controlled wrinkled portion of the return bend provides a constructive centerline radius (CCLR) of the return bend that is greater than the centerline radius; and 
 the return bend has a bend complexity factor (C B ) that is determined by the following relationship: 
 
       
         
           
             
               
                 C 
                 B 
               
               = 
               
                 
                   OD 
                   2 
                 
                 
                   CCLR 
                   × 
                   
                     WT 
                     2 
                   
                 
               
             
           
         
         wherein C B  permits bending of the return bend without an internal mandrel. 
       
     
     
         38 . The indirect heat exchanger pressure vessel of  claim 37  wherein C B  is approximately 10 or less. 
     
     
         39 . The indirect heat exchanger pressure vessel of  claim 29  wherein the serpentine circuit tubes each include an outer diameter (OD) and a wall thickness (WT), wherein: OD≥20×W. 
     
     
         40 . The indirect heat exchanger pressure vessel of  claim 29  wherein the inlet header, outlet header, and serpentine circuit tube are configured to operate at internal pressure of at least 150 psig. 
     
     
         41 . The indirect heat exchanger pressure vessel of  claim 29  wherein the inlet header, outlet header, and serpentine circuit tube are configured to operate at internal pressure of at least 410 psig. 
     
     
         42 . The indirect heat exchanger pressure vessel of  claim 29  wherein the inlet header, outlet header, and serpentine circuit tube are configured to operate at internal pressure of at least 1200 psig. 
     
     
         43 . The indirect heat exchanger pressure vessel of  claim 29  wherein the return bend comprises a first return bend adjacent one of the runs, a second return bend adjacent another run, and a connecting portion connecting the first bend and the second bend;
 wherein the bend angle comprises a first bend angle of the first bend and a second bend angle of the second bend; 
 wherein the controlled wrinkled portion comprises a first controlled wrinkled portion of the first bend and a second controlled wrinkled portion of the second bend; and 
 wherein the first wrinkled portion has a first angular extent about an inside of the first bend that is less than the first bend angle; and 
 wherein the second controlled wrinkled portion has a second angular extent about an inside of the second bend that is less than the second bend angle. 
 
     
     
         44 . The indirect heat exchanger pressure vessel of  claim 29  wherein the bend angle is 180 degrees and the angular extent of the controlled wrinkled portion is less than 170 degrees. 
     
     
         45 . The indirect heat exchanger pressure vessel of  claim 29  wherein the return bend has a bend complexity factor greater than or equal to 10. 
     
     
         46 . The indirect heat exchanger pressure vessel of  claim 29  wherein the return bend has a bend complexity factor of less than or equal to 20. 
     
     
         47 . An indirect heat exchanger pressure vessel comprising:
 an inlet header to receive a pressurized working fluid;   an outlet header to collect the pressurized working fluid;   a serpentine circuit tube connecting the inlet header and the outlet header to permit flow of the pressurized working fluid from the inlet header to the outlet header, the serpentine circuit tube including runs and a return bend connecting the runs, the return bend comprising:
 an inner portion having a sinusoidal wave pattern at an intrados of the return bend, the sinusoidal wave pattern including peaks and valleys; 
 wherein the inner portion of the bend includes an arc pattern intersecting the sinusoidal wave pattern, the arc pattern comprising peak arcs intersecting the peaks and valley arcs intersecting the valleys. 
   
     
     
         48 . The indirect heat exchanger pressure vessel of  claim 47  wherein the peak arcs have a first radius of curvature and the valley arcs have a second radius of curvature; and
 wherein the peak arc first radius of curvature and the valley arc second radius of curvature are substantially the same. 
 
     
     
         49 . The indirect heat exchanger pressure vessel of  claim 47  wherein the peak arcs have an angular extent that is greater than an angular extent of the valley arcs. 
     
     
         50 . The indirect heat exchanger pressure vessel of  claim 47  wherein the serpentine circuit tube has a centerline;
 wherein the peak arcs each have a center radially inward of the centerline; and 
 wherein the valley arcs each have a center radially outward of the centerline. 
 
     
     
         51 . The indirect heat exchanger pressure vessel of  claim 47  wherein the return bend has a midline plane, the sinusoidal pattern being in the midline plane;
 wherein the peak arcs are normal to the midline plane; and 
 wherein the valley arcs are normal to the midline plane. 
 
     
     
         52 . The indirect heat exchanger pressure vessel of  claim 47  wherein the sinusoidal pattern includes end peak portions adjacent the runs; and
 wherein at least one of the end peak portions includes a tapered lead-in segment. 
 
     
     
         53 . The indirect heat exchanger pressure vessel of  claim 47  wherein the sinusoidal pattern has a period and an amplitude; and
 wherein at least one of the period and the amplitude varies about the return bend. 
 
     
     
         54 . The indirect heat exchanger pressure vessel of  claim 53  wherein the sinusoidal pattern includes a first minimum amplitude adjacent one of the runs, a second minimum amplitude adjacent another one of the runs, and a maximum amplitude intermediate the first and second minimum amplitudes along the intrados of the bend. 
     
     
         55 . The indirect heat exchanger pressure vessel of  claim 47  wherein the peak and valley arcs each have an angular extent of at least 100 degrees. 
     
     
         56 . (canceled) 
     
     
         57 . The indirect heat exchanger pressure vessel of  claim 47  wherein the peak arcs have a shape defined by a portion of a first ellipse; and
 wherein the valley arcs have a shape defined by a portion of a second ellipse. 
 
     
     
         58 - 64 . (canceled)