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.

主权项

1. A method for conditioning cabin air comprising the steps of:
driving a primary air treatment unit with bleed air from an engine of an aircraft; wherein the primary air treatment unit includes a primary compressor, a first primary turbine, a second primary turbine, and a primary condenser; introducing a first portion of first primary turbine discharge air directly into an inlet of the primary compressor; driving the primary compressor simultaneously with both the first portion of the first primary turbine discharge air and with the bleed air; selectively driving a secondary air treatment unit with bleed air from the engine; wherein the secondary air treatment unit includes a secondary compressor, a secondary turbine, and a secondary condenser; cooling compressed air from the primary compressor with a second portion of the first primary turbine discharge air; cooling compressed air from the secondary compressor with the second portion of first primary turbine discharge air; driving the second primary turbine with the second portion of first primary turbine discharge air; selectively combining air outputs from both the primary and the secondary air treatment units; and delivering the combined outputs to the cabin.