US Patent 9623974 Aircraft environmental control system and method

An environmental control system including a turbomachine assembly having a shaft, motor, turbine and compressor, the compressor outputting a compressed air stream, a first valve that splits the compressed air stream into first and second compressed air streams, a heat exchanger to cool the first compressed air stream and output a cooled air stream, a second valve positioned to receive the cooled air stream and split the cooled air stream into first and second cooled air streams, wherein the first cooled stream is expanded in the turbine to produce an expanded air stream that is combined with the second compressed air stream and the second cooled air stream to provide a combined air stream having a temperature and a flow rate, and a controller that communicates control signals to the compressor, motor and first and second valves to control the temperature and flow rate of the combined air stream.