Tubular heat exchanger having multiple shell-side and tube-side fluid passes

A tubular heat exchanger comprising:

• a shell comprising a shell cavity, a shell inlet to introduce a shell-side fluid into the shell cavity, and a shell outlet to exhaust the shell-side fluid from the shell cavity, the shell extending along a longitudinal axis and having a length;
• the shell cavity comprising a plurality of longitudinal baffles dividing the shell cavity into multiple vertically stacked shell-side flow passes, wherein the shell-side fluid traverses the length of the shell cavity more than twice between the shell inlet and the shell outlet;
• a stationary head attached to the shell and comprising an internal tube-side plenum fluidly isolated from the shell cavity, a tube-side inlet to introduce a tube-side fluid into the tube-side plenum, and a tube-side outlet to discharge the tube-side fluid from the tube-side plenum;
• a plurality of vertically stacked horizontal rows of tube bundle sets inside the shell and in fluid communication with the tube-side plenum, each tube bundle set comprising an outer tube bundle array and an inner tube bundle array nested inside the outer tube bundle array;
• each shell-side flow pass including a tube bundle set which forms a plurality of tube-side flow passes in each shell-side flow pass;
• wherein the tube-side fluid flows in a vertically cascading pattern from an uppermost tube bundle set fluidly coupled to the tube-side inlet, through a plurality of intermediate tube bundle sets, and to a lowermost tube bundle set fluidly coupled to the tube-side outlet;
• wherein the tube-side fluid flows horizontally in each tube bundle set before cascading to a next tube bundle set;
• and
• wherein the tube-side fluid in the uppermost tube bundle set flows from the tube-side inlet to the inner tube bundle array and then to the outer tube bundle array, the tube-side fluid in the intermediate tube bundle set adjacent the uppermost tube bundle set flows from the outer tube bundle array to the inner tube bundle array, and the tube-side fluid in the lowermost tube bundle set flows from the outer tube bundle array to the inner tube bundle array and then to the tube-side outlet.

A method for operating a tubular heat exchanger, the method comprising:

• providing a heat exchanger including a shell defining a plurality of vertically stacked shell-side fluid passes, a tube-side plenum fluidly isolated from the shell-side and comprising a plurality of tube-side fluid passes, and a plurality of vertically stacked horizontal rows of tube bundle sets inside the shell and in fluid communication with the tube-side plenum;
• receiving a tube-side fluid in a first one of the tube-side fluid passes;
• the tube-side fluid flowing horizontal through a first set of horizontally arranged tube-side fluid passes in a first one of the tube bundle sets in a first one of the vertically stacked shell-side fluid passes;
• the tube-side fluid cascading vertically to an adjacent second one of the vertically stacked shell-side fluid passes;
• the tube-side fluid flowing horizontally through a second set of horizontally arranged tube-side fluid passes in a second one of the tube bundle sets in the second one of the vertically stacked shell-side fluid passes;
• the tube-side fluid cascading vertically to an adjacent third one of the vertically stacked shell-side fluid passes;
• and
• the tube-side fluid flowing horizontally through a third set of horizontally arranged tube-side fluid passes in a third one of the tube bundle sets in the third one of the vertically stacked shell-side fluid passes;
• and
• wherein the tube-side fluid progresses from an inner portion of the first one of the tube bundle sets to an outer portion in flowing horizontally through the first set of horizontally arranged tube-side fluid passes, wherein the tube-side fluid progresses from an outer portion of the second one of the tube bundle sets to an inner portion in flowing horizontally through the second set of horizontally arranged tube-side fluid passes, and wherein the tube-side fluid progresses from an inner portion of the third one of the tube bundle sets to an outer portion in flowing horizontally through the third set of horizontally arranged tube-side fluid passes.