Environmental Control System Testing and Performance Evaluation of a Transport Aircraft

摘要

Environmental Control System (ECS) or Air Management System is a generic term used in aircraft industry for system and equipment associated with cooling, heating, ventilation, humidity/contaminant control and pressurization within aircraft occupied compartments, cargo compartments and electronic equipment bays. It also caters to other pneumatic demands like windshield demisting, aerofoil anti-icing, door-sealing, fuel-tank pressurization and engine bay ventilation. The real challenge for an ECS is to operate and supply adequate cooling over a wide range of ground and flight conditions in a most reliable and efficient manner. udVentilation to the cabin is normally through Environmental Control System (ECS), emergency back-up pressurization system and by ram air. Engines bleed air is used by the environmental control system to provide pressurization to the cabin. Refrigeration of the air is produced by a single bootstrap air cycle system (Air Conditioning Pack). The bleed air temperature control is accomplished automatically by an electronic controller in conjunction with an Electro Pneumatic Temperature Control Valve (TCV). This system is designed to maintain the cabin and crew compartment temperature in the range of 18 to 30°C up to the aircraft ceiling of altitude of 30,000 ft. This paper covers the system performance evaluation carried out for various engine power settings during ground tests on the aircraft and by empirical method. Further, instrumentation scheme adapted for measuring pressure and temperature for the above said evaluation has been discussed. Results of the tests show that the required mass flow rate and condition of the air entering in to the cabin is met, thus ECS performance is satisfactory.ud