Indirect Heat Exchanger Pressure Vessel with Controlled Wrinkle Bends

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.

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.