ENGINE BLEED AIR SYSTEM

摘要

An engine bleed air system (3) has one or more taps in the compressor section of an aircraft engine, for example a low pressure tap (19) and a high pressure tap (20). The low pressure tap (19) is fluidly connected to the compressor (21) of a turbo-compressor and the high pressure tap (20) is fluidly connected to the turbine (22) of the turbo-compressor. A bypass line (30) connects the high pressure air to the outlet (32) of the compressor (21), with a heat exchanger (31) used to remove excess heat from the bypass line (30). An additional heat exchanger (37) is used to remove any excess heat from the compressed air, dumping the heat to a fan stream (33) or to the expanded air exiting the turbine (22). The system is controlled to minimize the amount of high pressure air extracted from the engine.