Condenser Ice Removal for Environmental Control System

摘要

Environmental control system bleed air is cooled by a heat exchanger. A fan pulls ambient air from a ram inlet duct across the at least heat exchanger and to an outlet. An air cycle machine drives the fan. The bleed air passes downstream of the at least heat exchanger to a compressor, and then drives a first stage turbine. The first stage turbine has an outlet communicating with a condenser, and then a second stage turbine. An icing control system taps hot air downstream of the compressor. An add heat valve is selectively moveable between a first position blocking flow from the tap passage. A second position where it passes air from the tap passage to the condenser inlet, and to a point downstream of the condenser and to the second stage turbine. In a third position, the valve only communicates air from the tap passage into the condenser.

主权项

1. An environmental control system comprising:
an inlet duct for receiving inlet hot air, at least one heat exchanger in the path of the hot air between the inlet duct and an outlet to cool the hot air, a fan to pull ram air for cooling the hot air as it passes the at least one heat exchanger; an air cycle machine for driving said fan, the hot air passing downstream of the at least one heat exchanger to be compressed by a compressor, and then drives a first stage turbine, said first stage turbine having an outlet communicating with a condenser, and said condenser having an outlet communicating with a second stage turbine; and an icing control system including a tap passage for tapping hot air downstream of said compressor, and to an add heat valve, the add heat valve being selectively moveable between three positions, including a first position where it blocks flow from said tap passage into a condenser line leading to an inlet to said condenser, a second position where it passes air from said tap passage both into said condenser line, and further to a point downstream of said condenser and passing to said second stage turbine, and a third position wherein said add heat valve only communicates air from said tap passage into said condenser line leading to said condenser inlet.