Tube heat exchanger using 3-tube bundles

A process of utilizing a heat exchanger, the process comprising:

• providing a primary inlet manifold and a primary outlet manifold supporting at least one tube bundle at opposite ends;
• fluidly coupling an inlet end piece of said at least one tube bundle with an outlet end piece of said at least one tube bundle;
• and
• fluidly coupling in series the inlet end piece with each of a first tube, a second tube and a third tube to the outlet end piece, wherein said outlet end piece includes a first turn portion fluidly coupled between the first tube and the second tube, wherein said inlet end piece includes a second turn portion fluidly coupled between the second tube and the third tube.

A heat exchanger comprising:

• a primary inlet manifold and a primary outlet manifold supporting at least one tube bundle at opposite ends;
• said at least one tube bundle comprising:
• an inlet end piece with each of a first tube, a second tube and a third tube fluidly coupled in series to an outlet end piece;
• and
• the first tube, the second tube and the third tube forming one of a coiled tube arrangement and a straight tube arrangement, wherein each of the first tube, the second tube and the third tube includes a first end opposite a second end with a central section spanning between the first end and second end;
• the central section is configured to be exposed to the external flow;
• and each of the first tube, the second tube and the third tube includes a first straight section proximate the first end and a second straight section proximate the second end;
• wherein each of the first tube, the second tube and the third tube includes a first transition zone located between the first straight section and the central section;
• wherein each of the first tube, the second tube and the third tube includes a second transition zone located between the second straight section and the central section;
• wherein the first transition zone and second transition zone are shaped with a smooth helical pitch that transitions from a straight walled configuration to a constant pitch of the central section.