High pressure compressor diffuser for an industrial gas turbine engine
A gas turbine engine with an air cooled turbine part in which spent cooling air for the turbine part is discharged into the combustor instead of into the hot gas stream of the turbine in order to increase efficiency of the engine. Turbine rotor blades and stator vanes are cooled. The spent cooling air is passed into a diffuser located between the HPC outlet and the combustor inlet where the spent cooling air is discharged along the inner and outer endwalls of the diffuser in directions substantially parallel to the inner and outer diffuser endwalls and at a greater velocity in order to energize the diffuser endwall boundary layers so that they can sustain higher diffusion rates and levels.
1 : A diffuser for a gas turbine engine in which compressed air from a compressor is decreased in velocity and increased in pressure prior to passage into a combustor, the diffuser comprising:
an inlet end to receive compressed air from the compressor and an outlet end to discharge compressed air at a higher pressure to a combustor;
an inner turn channel to receive compressed air from a first source and discharge the compressed air substantially parallel to the diffuser inner endwall; and,
an outer turn channel to receive compressed air from a second source and discharge the compressed air substantially parallel to the diffuser outer endwall.
2 : The diffuser for a gas turbine engine of claim 1 , and further comprising:
the diffuser has inner and outer endwalls angled at about 8 degrees from the engine centerline.
3 : The diffuser for a gas turbine engine of claim 1 , and further comprising:
the diffuser length is about 7 times the inlet height of the diffuser.
4 : The diffuser for a gas turbine engine of claim 1 , and further comprising:
the area ratio of the diffuser is around 3 to 3.5.
5 : A gas turbine engine comprising:
a compressor to produce a compressed air flow;
a turbine to drive the compressor using a hot gas flow;
a combustor to produce the hot gas flow;
an air cooled component of the turbine;
a diffuser located between the compressor and the combustor to diffuse the compressed air flow from the combustor; and,
the diffuser having a turn channel to discharge spent cooling air from the air cooled turbine component into the diffuser at an angle substantially parallel to the diffuser endwall.
6 : The gas turbine engine of claim 5 , and further comprising:
the turbine includes a first air cooled component and a second air cooled component;
the diffuser includes an inner turn channel to receive spent cooling air from the first air cooled turbine component; and,
the diffuser includes an outer turn channel to receive spent cooling air from the second air cooled turbine component.
7 : The gas turbine engine of claim 6 , and further comprising:
the first air cooled turbine component is a turbine rotor blade; and,
the second air cooled turbine component is a turbine stator vane.
8 : The gas turbine engine of claim 6 , and further comprising:
the inner turn channel and the outer turn channel both discharge the spent cooling air into the compressed air flow from the compressor in directions substantially parallel to the inner and outer diffuser endwalls, respectively.
9 : The gas turbine engine of claim 5 , and further comprising:
the gas turbine engine is an industrial gas turbine engine; and,
the industrial gas turbine engine drives an electric generator to produce electrical power.