ENVIRONMENTAL CONTROL SYSTEM WITH CLOSED LOOP PRESSURE CYCLE

摘要

An environmental control system (ECS) for providing conditioned air to a cabin of an aircraft at a desired rate may include a bleed-air driven primary air treatment unit configured to produce pack supply air and to recirculate a portion of the pack supply air into a compressor of the primary air treatment unit. The ECS may also include a bleed-air driven secondary air treatment unit configured to compress ram air at a rate that corresponds to the rate of recirculation. The ECS may be configured to selectively deliver conditioned air from both the primary and the secondary air treatment units to the cabin.