A heat exchanger , in particular a shell-and-tube heat exchanger, for arrangement in a rotor having an axis of rotation , comprising: first heat-exchange channels for guiding a first heat-exchange medium, in particular a liquid; second heat-exchange channels for guiding a second heat-exchange medium, in particular a gas, preferably a noble gas, wherein the second heat-exchange channels comprise, in the assembled usage state, at least one inner heat-exchange channel, which is closer to the axis of rotation , and one outer heat-exchange channel, which is further away from the axis of rotation ; a distribution element , which expands, preferably conically expands, in the direction of flow of the second heat-exchange medium for feeding the second heat-exchange medium from an entry opening in the distribution element into inflow openings in the second heat-exchange channels ; a merger element , which tapers, preferably tapers substantially conically, in the direction of flow of the second heat-exchange medium for discharging the second heat-exchange medium from outflow openings in the second heat-exchange channels into an exit opening in the merger element , characterised by a device for homogenising the flow through the second heat-exchange channels , comprising a throttle member for throttling, to different extents, an inner flow of the second heat-exchange medium that passes through the inner one of the second heat-exchange channels , and an outer flow of the second heat-exchange medium that passes through the outer one of the second heat-exchange channels between the entry opening in the distribution element and the exit opening in the merger element . first heat-exchange channels for guiding a first heat-exchange medium, in particular a liquid; second heat-exchange channels for guiding a second heat-exchange medium, in particular a gas, preferably a noble gas, wherein the second heat-exchange channels comprise, in the assembled usage state, at least one inner heat-exchange channel, which is closer to the axis of rotation , and one outer heat-exchange channel, which is further away from the axis of rotation ; a distribution element , which expands, preferably conically expands, in the direction of flow of the second heat-exchange medium for feeding the second heat-exchange medium from an entry opening in the distribution element into inflow openings in the second heat-exchange channels ; a merger element , which tapers, preferably tapers substantially conically, in the direction of flow of the second heat-exchange medium for discharging the second heat-exchange medium from outflow openings in the second heat-exchange channels into an exit opening in the merger element , characterised by a device for homogenising the flow through the second heat-exchange channels , comprising a throttle member for throttling, to different extents, an inner flow of the second heat-exchange medium that passes through the inner one of the second heat-exchange channels , and an outer flow of the second heat-exchange medium that passes through the outer one of the second heat-exchange channels between the entry opening in the distribution element and the exit opening in the merger element . <EOS>