Heat recovery steam generator with parallel tube bundles

A heat exchanger, comprising:

• a shell defining an internal room, an inlet for a first heat exchange fluid, and an outlet for the first heat exchange fluid,
• the internal room comprising:
• at least one wall dividing said internal room into separate sections,
• the separate sections including at least one first heat exchange section and at least one second heat exchange section,
• the first heat exchange section having a first heat exchange section inlet for the first heat exchange fluid and a first heat exchange section outlet for the first heat exchange fluid, and
• the second heat exchange section-having a second heat exchange section inlet for the first heat exchange fluid and a second heat exchange section outlet for the first heat exchange fluid,
• wherein at least one first tube bundle is arranged inside the first heat exchange section and at least one second tube bundle is arranged inside the second heat exchange section,
• the first tube bundle having a first tube bundle inlet and a first tube bundle outlet and the second tube bundle having a second tube bundle inlet and a second tube bundle outlet,
• the first tube bundle inlet being connected to a first feed line of a second heat exchange fluid and the second tube bundle inlet being connected to a second feed line of the second or a further heat exchange fluid,
• at least one additional separate section being arranged inside said internal room, in between said first heat exchange section and said second heat exchange section,
• the additional separate section having an additional separate section inlet for the first heat exchange fluid and an additional separate section outlet for the first heat exchange fluid,
• the additional separate section being a first heat exchange fluid bypass section, wherein each heat exchange section is provided with respective flow regulating means.