Heat exchange system for an aircraft turbine engine

A turbine engine for an aircraft having a heat exchange system, the system comprising:

• two annular walls, external and internal respectively, which extend around each other and around a same axis (X), and which are configured to define between them a flow duct (V2) for a gas flow (F2),
• a first annular heat exchange device which extends around the axis (X) and is carried by one of said walls, and which is located in the duct (V2), the first device comprising a heat exchange matrix interposed between the wall and a cowl which has a predetermined diameter D1 measured at the axial center of the heat exchange matrix of the first device,
• a second annular heat exchange device which extends around the axis (X) and is located in the duct (V2), the second device comprising a heat exchange matrix which is axially spaced from the heat exchange matrix of the first device and which is interposed between the cowl of the first device and the opposite wall or another cowl of the second device, the cowl of the first device having a predetermined diameter D2 measured at the axial center of the heat exchange matrix of the second device,
• wherein D2 is greater than D1 when the first device is carried by the external wall, or
• D2 is less than D1 when the first device is carried by the internal wall.