A coil-wound heat exchanger comprising: a shell (415/515); a first bundle (412/512) comprising a first bundle end (476/574) and a second bundle end (474/576) located distal to the first bundle end; a mandrel (430/530) centrally located within the first bundle (412/512), a first bundle shell space extending from the first bundle end (476/574) to the second bundle end (474/576) and extending from the first bundle mandrel to the shell (415/515); a plurality of tubes (429a-c,431a-c) located in the first bundle shell space, each of the plurality of tubes having a first tube end located at the first bundle end (476/574) and a second tube end located at the second bundle end (474/576), the plurality of tubes being wound around the mandrel (430/530) forming a plurality of wound layers, the plurality of wound layers being divided into a plurality of zones (450,452,454/550,552,554) that are concentrically arranged in the first bundle shell space, the plurality of tubes comprising a plurality of tube sets, each of the plurality of tube sets being located in a different one of the plurality of zones; a first group of tube sheets (432,435,434/526,533,528) located at the first bundle end (476/574); a plurality of valves (462,464,466/562,564,566), each of the plurality of valves being in fluid flow communication with each of the first group of tube sheets (432,435,434/526,533,528) and located at the first bundle end (476/574); and a second group of tube sheets (426,428/532,534) located at the second bundle end (474/576), at least one of the second group of tube sheets being in fluid flow communication with more than one of the plurality of tube sets at the second tube end; characterized in that each of the first group of tube sheets (432,435,434/526,533,528) is in fluid flow communication with only one of the plurality of tube sets at the first tube end. a shell (415/515); a first bundle (412/512) comprising a first bundle end (476/574) and a second bundle end (474/576) located distal to the first bundle end; a mandrel (430/530) centrally located within the first bundle (412/512), a first bundle shell space extending from the first bundle end (476/574) to the second bundle end (474/576) and extending from the first bundle mandrel to the shell (415/515); a plurality of tubes (429a-c,431a-c) located in the first bundle shell space, each of the plurality of tubes having a first tube end located at the first bundle end (476/574) and a second tube end located at the second bundle end (474/576), the plurality of tubes being wound around the mandrel (430/530) forming a plurality of wound layers, the plurality of wound layers being divided into a plurality of zones (450,452,454/550,552,554) that are concentrically arranged in the first bundle shell space, the plurality of tubes comprising a plurality of tube sets, each of the plurality of tube sets being located in a different one of the plurality of zones; a first bundle end (476/574) and a second bundle end (474/576) located distal to the first bundle end; a mandrel (430/530) centrally located within the first bundle (412/512), a first bundle shell space extending from the first bundle end (476/574) to the second bundle end (474/576) and extending from the first bundle mandrel to the shell (415/515); a plurality of tubes (429a-c,431a-c) located in the first bundle shell space, each of the plurality of tubes having a first tube end located at the first bundle end (476/574) and a second tube end located at the second bundle end (474/576), the plurality of tubes being wound around the mandrel (430/530) forming a plurality of wound layers, the plurality of wound layers being divided into a plurality of zones (450,452,454/550,552,554) that are concentrically arranged in the first bundle shell space, the plurality of tubes comprising a plurality of tube sets, each of the plurality of tube sets being located in a different one of the plurality of zones; a first group of tube sheets (432,435,434/526,533,528) located at the first bundle end (476/574); a plurality of valves (462,464,466/562,564,566), each of the plurality of valves being in fluid flow communication with each of the first group of tube sheets (432,435,434/526,533,528) and located at the first bundle end (476/574); and a second group of tube sheets (426,428/532,534) located at the second bundle end (474/576), at least one of the second group of tube sheets being in fluid flow communication with more than one of the plurality of tube sets at the second tube end; characterized in that each of the first group of tube sheets (432,435,434/526,533,528) is in fluid flow communication with only one of the plurality of tube sets at the first tube end.