AIRCONDITIONING SYSTEM
-The system is fully automatic.
-Provides continuous air renewal and maintains a constant, selected temperature
in the following three (3) zones: COCKPIT, FWD CABIN, AFT CABIN. These three
(3) zones are independently controlled.
-The purpose is to supply:
1. Fresh air at the correct temperature and pressure.
2. To provide ventilation and pressurization in the cockpit and cabin.
SIMPLIFIED OPERATION:
PNEUMATIC AIR > PACK FLOW CONTROL VALVE > PACKS > MIXING UNIT
(PACKS+CABIN AIR+EMERGENCY RAM AIR+LP GROUND CONNECTION) + TRIM
AIR > TRIM AIR VALVE > ZONE
OVERVIEW OF OPERATION
1. Receives air supply from the pneumatic system via the PACK FLOW
CONTROL VALVE.
2. From the PACK FLOW CONTROL VALVE, it feeds the hot pneumatic air to
its respective PACK.
3. The PACK cools the hot pneumatic air to a basic temperature.
4. Cooled air from the PACKS is sent to the MIXING UNIT which mixes cold
air from the PACKS with RECIRCULATING CABIN AIR to regulate the air
temperature. Also receives conditioned air from a low-pressure ground
connection and fresh ambient air from the EMERGENCY RAM AIR INLET.
5. The HOT AIR PRESSURE REGULATING VALVE and TRIM AIR VALVE enable
fine adjustment of temperature of the air that leaves the mixing unit.
1. PACK FLOW CONTROL VALVE
- Pneumatically-operated and
Electrically-controlled.
- regulates the air flow in accordance
with the ACSC.
- spring loaded closed when the air
pressure is not available.
- closes automatically in the event of
pack overheating, engine starting or
operation of the fire or ditching
switch.
2. PACKS (PNEUMATIC AIR CYCLE KIT)
- operates automatically and
independently of each other and
is controlled by their respective
Air
Conditioning
System
Controller (ACSC).
HOW DOES IT WORK?
1. Bleed air enters the
PACK FLOW CONTROL
VALVE.
2. Air flows to the
PRIMARY
HEAT
EXCHANGER
and
temperature decreases.
3. Air flows to the
COMPRESSOR; air is
then compressed and
both
air
and
temperature increases.
4. Air goes to the MAIN HEAT EXCHANGER, air temperature decreases,
pressure remains the same.
5. Air is dried in the WATER SEPARATOR SYSTEM before it goes to the
TURBINE; air expands and both temperature and pressure decreases
then it powers to drive the COMPRESSOR and FAN in the AIR CYCLE
MACHINE.
2.1 PRIMARY HEAT AND MAIN HEAT EXCHANGER