A thermal management system including: - a housing having a hollow interior (3, 21), an inlet and an outlet for a fluid, and, disposed in said hollow interior (3, 21): - a plurality of heat exchange and positioning devices, each comprising: -- a central body containing a material for storing thermal energy by latent heat accumulation, to be placed in thermal exchange with the fluid, and -- a structure for positioning the central body in said hollow interior, the positioning structure being connected to the central body around which it extends and reserving passages enabling contact between the central body and the surrounding fluid and a circulation of said fluid, characterized in that: - the positioning structure comprises an external structure defining a cylinder and connected by transverse arms to the central body, or - the positioning structure comprises an external structure defining a ring and connected by transverse arms to the central body, or - the positioning structure includes a peripheral structure (270, 35) extending circumferentially around the central body, in several planes, to separate it from a surrounding support in several directions, or - the positioning structure comprises an external structure: -- defining a discontinuous sphere, -- and connected to the central body by transverse arms around the central body, or - the positioning structure includes a cellular structure surrounding the central body, in contact with it, or - the positioning structure includes one or more linear beads surrounding the central body, in contact with it, or recesses formed in said body. - a housing having a hollow interior (3, 21), an inlet and an outlet for a fluid, and, disposed in said hollow interior (3, 21): - a plurality of heat exchange and positioning devices, each comprising: -- a central body containing a material for storing thermal energy by latent heat accumulation, to be placed in thermal exchange with the fluid, and -- a structure for positioning the central body in said hollow interior, the positioning structure being connected to the central body around which it extends and reserving passages enabling contact between the central body and the surrounding fluid and a circulation of said fluid, -- a central body containing a material for storing thermal energy by latent heat accumulation, to be placed in thermal exchange with the fluid, and -- a structure for positioning the central body in said hollow interior, the positioning structure being connected to the central body around which it extends and reserving passages enabling contact between the central body and the surrounding fluid and a circulation of said fluid, - the positioning structure comprises an external structure defining a cylinder and connected by transverse arms to the central body, or - the positioning structure comprises an external structure defining a ring and connected by transverse arms to the central body, or - the positioning structure includes a peripheral structure (270, 35) extending circumferentially around the central body, in several planes, to separate it from a surrounding support in several directions, or - the positioning structure comprises an external structure: -- defining a discontinuous sphere, -- and connected to the central body by transverse arms around the central body, or -- defining a discontinuous sphere, -- and connected to the central body by transverse arms around the central body, or - the positioning structure includes a cellular structure surrounding the central body, in contact with it, or - the positioning structure includes one or more linear beads surrounding the central body, in contact with it, or recesses formed in said body.