A tube heat exchanger for exchanging heat from a first fluid to a second fluid, comprising a tubular shell; an inner wall extending around a center axis of said tubular shell and forming a central chamber internally of said inner wall, and an annular heat exchange space extending externally of said inner wall and enclosed by said tubular shell, wherein the heat exchange space comprises a plurality of axially extending heat exchange sectors separated by radially extending separating walls, and flow paths of the first fluid and the second fluid extend in the heat exchange space, wherein adjacent heat exchange sectors communicate; a set of flow tubes extending axially in each of said heat exchange sectors in said heat exchange space; a first connection for inlet of the first fluid to a first set of flow tubes, and a second connection for outlet of said first fluid; at least one radially extending baffle dividing said heat exchange sectors into at least two axially displaced heat exchange segments, wherein the central chamber communicates with at least one opening in a tubeplate, and wherein a flow passage is provided between adjacent heat exchange segments to provide a flow path of the second fluid in a vertical direction between the adjacent heat exchange segments; a third connection for inlet of the second fluid to a first heat segment of a heat exchange sector, and a fourth connection for outlet of said second fluid; wherein a first flow path of said first fluid and a second flow path of said second fluid are divided to flow by a first portion clockwise and a second portion anti-clockwise through the axially extending heat exchange sectors, wherein a flow path of the second fluid extends radially in opposite directions in adjacent heat exchange segments in the heat exchange sectors, and a flow path of the first fluid extends perpendicular to the flow path of the second fluid. a tubular shell; an inner wall extending around a center axis of said tubular shell and forming a central chamber internally of said inner wall, and an annular heat exchange space extending externally of said inner wall and enclosed by said tubular shell, wherein the heat exchange space comprises a plurality of axially extending heat exchange sectors separated by radially extending separating walls, and flow paths of the first fluid and the second fluid extend in the heat exchange space, wherein adjacent heat exchange sectors communicate; a set of flow tubes extending axially in each of said heat exchange sectors in said heat exchange space; a first connection for inlet of the first fluid to a first set of flow tubes, and a second connection for outlet of said first fluid; at least one radially extending baffle dividing said heat exchange sectors into at least two axially displaced heat exchange segments, wherein the central chamber communicates with at least one opening in a tubeplate, and wherein a flow passage is provided between adjacent heat exchange segments to provide a flow path of the second fluid in a vertical direction between the adjacent heat exchange segments; a third connection for inlet of the second fluid to a first heat segment of a heat exchange sector, and a fourth connection for outlet of said second fluid; wherein a first flow path of said first fluid and a second flow path of said second fluid are divided to flow by a first portion clockwise and a second portion anti-clockwise through the axially extending heat exchange sectors, wherein a flow path of the second fluid extends radially in opposite directions in adjacent heat exchange segments in the heat exchange sectors, and a flow path of the first fluid extends perpendicular to the flow path of the second fluid.