Simplified engine bleed supply with low pressure environmental control system for aircraft
An environmental control system includes a low pressure tap at a location on a first compressor section of a main compressor section. The low pressure tap communicates airflow to a first passage leading to a downstream outlet. A compressor is driven by an electric motor. A combined outlet intermixes airflow from the first passage and from the compressor driven by the electric motor and passes the airflow downstream to be delivered to an aircraft use.
1. A gas turbine engine assembly for an aircraft comprising:
a fan section delivering air into a main compressor section, said main compressor section including a first compressor section and a second compressor section operating at a higher pressure than the first compressor section, said main compressor section compressing the air and delivering the air into a combustion section where the air is mixed with fuel and ignited to generate products of combustion that are passed over a turbine section to drive said fan section and main compressor section;
an environmental control system including a low pressure tap at a location on the first compressor section of the main compressor section, wherein the low pressure tap communicates airflow to a first passage leading to a downstream outlet, and a compressor driven by an electric motor;
a first control valve downstream the low pressure tap for controlling the airflow into the compressor driven by the electric motor;
a second control valve for controlling the airflow to the compressor driven by the electric motor;
a combined outlet intermixing airflow from the first passage and from the compressor driven by the electric motor and passing the airflow downstream to be delivered to an aircraft use; and
an electronic controller configured for controlling the first control valve and the second control valve in response to a signal indicative of an overspeed condition of the electric motor.
2. The gas turbine engine assembly as recited in claim 1 , including a gearbox driven by a fan drive turbine of the turbine section to drive said fan section, wherein the gearbox provides a gear reduction.
3. The gas turbine engine assembly as recited in claim 1 , wherein the turbine section includes a first turbine section driving the second compressor section, an intermediate turbine section driving the first compressor section and a third turbine section driving the fan section.
4. The gas turbine engine assembly as recited in claim 1 , wherein the first compressor section includes at least four (4) stages and no more than eight (8) stages.
5. The gas turbine engine assembly as recited in claim 4 , wherein bleed air is taken from a third stage of the first compressor section.
6. The gas turbine engine assembly as recited in claim 1 , including a check valve between the low pressure tap and the combined outlet.