Turbine cooling air from a centrifugal compressor

A gas turbine engine turbine cooling system comprising:

• an annular centrifugal compressor impeller of a high pressure rotor and a diffuser directly downstream of the impeller,
• a cooling air bleed means for bleeding clean cooling air from a bleed location downstream of an outlet of the diffuser,
• one or more channels in fluid communication with the cooling air bleed means, each of the one or more channels having a generally radially extending section followed by a generally axially aftwardly extending section,
• the one or more channels terminating at and in fluid communication with an annular cooling air plenum having one or more accelerators,
• an annular combustor stator assembly including a radially extending forward end wall extending radially outwardly from and joined to an inner combustor casing,
• a radially outer portion of the forward end wall being an aft wall of the diffuser,
• a stator plenum disposed between and in fluid communication with the impeller and an annular cavity extending radially between the inner combustor casing and the high pressure rotor and extending axially between forward and aft thrust balance seals,
• the stator plenum being bounded by a radially inner portion of the forward end wall and an annular cover spaced axially aftwardly of the radially inner portion of the forward end wall, and
• each of the cooling channels having a channel inner wall running along a radially outer portion of the forward end wall, the annular cover, and the inner combustor casing.

A gas turbine engine turbine cooling system comprising:

• an annular centrifugal compressor impeller of a high pressure rotor and a diffuser directly downstream of the impeller,
• a cooling air bleed means for bleeding clean cooling air from a bleed location downstream of an outlet of the diffuser,
• one or more channels in fluid communication with the cooling air bleed means, each of the one or more channels having a generally radially extending section followed by a generally axially aftwardly extending section,
• the one or more channels terminating at and in fluid communication with an annular cooling air plenum having one or more accelerators,
• the generally radially and axially aftwardly extending sections being connected by a bend section of the cooling air channel and the generally axially aftwardly extending section being angled radially inwardly going from the bend section to the cooling air plenum,
• an annular combustor stator assembly including a radially extending forward end wall extending radially outwardly from and joined to an inner combustor casing,
• a radially outer portion of the forward end wall being an aft wall of the diffuser,
• a stator plenum disposed between and in fluid communication with the impeller and an annular cavity extending radially between the inner combustor casing and the high pressure rotor and extending axially between forward and aft thrust balance seals,
• the stator plenum being bounded by a radially inner portion of the forward end wall and an annular cover spaced axially aftwardly of the radially inner portion of the forward end wall, and
• each of the cooling channels having a channel inner wall formed by and running along a radially outer portion of the forward end wall, the annular cover, and the inner combustor casing.

A gas turbine engine assembly comprising:

• a combustor between a high pressure compressor and a high pressure turbine,
• a high pressure rotor including a centrifugal compressor having an annular centrifugal compressor impeller directly adjacent to and downstream of a diffuser,
• a cooling air bleed means for bleeding clean cooling air from a bleed location downstream of an outlet of the diffuser,
• one or more channels in fluid communication with the cooling air bleed means,
• each of the one or more channels having a generally radially extending section followed by a generally axially aftwardly extending section,
• the one or more channels terminating at and in fluid communication with an annular cooling air plenum having one or more accelerators, and
• a generally axially aftwardly extending section of each of the one or more channels terminating at an aft conical section including cooling air apertures of an inner combustor casing diverging outwardly with respect to an engine centerline and disposed between the one or more channels and the annular cooling air plenum.

A gas turbine engine assembly comprising:

• a combustor between a high pressure compressor and a high pressure turbine,
• a high pressure rotor including a centrifugal compressor having an annular centrifugal compressor impeller directly adjacent to and downstream of a diffuser,
• a cooling air bleed means for bleeding clean cooling air from a bleed location downstream of an outlet of the diffuser,
• one or more channels in fluid communication with the cooling air bleed means, each of the one or more channels having a generally radially extending section followed by a generally axially aftwardly extending section,
• the one or more channels terminating at and in fluid communication with an annular cooling air plenum having one or more accelerators,
• an annular combustor stator assembly including a forward end wall extending radially outwardly from and joined to an inner combustor casing,
• a radially outer portion of the forward end wall being an aft wall of the diffuser,
• a stator plenum disposed between and in fluid communication with the impeller and an annular cavity extending radially between the inner combustor casing and the high pressure rotor and extending axially between forward and aft thrust balance seals, and
• the stator plenum being in part bounded by a radially inner portion of the forward end wall.