Patent ID: 10011361

Abstract:
An Environmental Control System (ECS) which includes a heat exchanger (HX) and an air conditioning unit (ACU) upstream of the heat exchanger. The heat exchanger receives flows of hot air bled from a plurality of aircraft engines and flows of cold ambient air drawn from the aircraft exterior for use by the heat exchanger and the air conditioning unit for heating and cooling the interior cabin of the aircraft. The environmental control system may operate in one of several modes, whether the heat exchanger and air conditioning unit are operating normally or have failed. In a normal mode, the air conditioning unit and heat exchanger operate in series. In an “ACU only” mode, the air conditioning unit operates without the heat exchanger. In an “HX only” mode, the heat exchanger operates without the air conditioning unit. In an “ECS off” mode, both the heat exchanger and air conditioning unit are bypassed.