Cooling the upstream end plate of a high pressure turbine by means of a system of dual injectors at the end of the combustion chamber

A ventilation device for a high pressure turbine rotor of a turbomachine, said turbine being disposed downstream from the combustion chamber and comprising firstly a turbine disk presenting an internal aperture and an upstream flange for fixing to the downstream cone of a high pressure compressor, and secondly an end plate disposed upstream from said disk and separated therefrom by a cavity, said end plate comprising a solid radially inner portion likewise having an internal aperture, through which the upstream flange of said disk extends, and an upstream flange for being fixed to said downstream cone, said device comprising a first circuit for cooling blades fed with a first flow of air taken from the end of the combustion chamber and delivering said first flow of air into said cavity via main injectors disposed upstream from said end plate, and ventilation holes formed through said end plate, and a second circuit for cooling the end plate fed with a second flow of air through a discharge baffle situated downstream from the high pressure compressor, at least a fraction of said second air flow serving to ventilate the upstream top face of said end plate through a second baffle situated beneath the injectors,

• the device further comprising a branch connection between the first circuit and the enclosure situated downstream from the second baffle, said branch connection delivering a third flow of air for cooling the upstream top face of the radially inner portion of said end plate, said third flow of air being entrained into pre-rotation by means of additional injectors.