BOMBARDIER BD-100-1A10, Operating Manual

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AIR CONDITIONING/PRESSURIZATION
Volume 2 Flight Crew Operating Manual Sep 13/2004
02-03-02
CSP 100-6
REV 1
AIR CONDITIONING SYSTEM (Cont)
AIR CONDITIONING PACK
The air conditioning pack (PACK) provides conditioned air for the fuselage compartments by decreasing the temperature
and water content of the bleed air used in the conditioning process.
The PACK is supplied with pre-cooled bleed air, for cabin air conditioning and cabin pressurization.
On leaving the precooler, bleed air is ducted into the PACK, at the primary heat exchanger inlet. The primary heat exchang-
er is used to reduce bleed air temperature. On leaving the primary heat exchanger, the bleed air is directed into the com-
pressor of the air cycle machine, where the temperature and pressure increases.
The air then flows through the secondary heat exchanger, where a pressure loss occurs and the temperature is reduced by
exchanging heat with the ram air before flowing to the reheater/condenser.
At the condenser outlet, the condensed water is extracted by centrifugal effect in the water extractor then routed to the re-
heater cold air pass where air temperature increases prior to entering the air cycle machine.
The air is then expanded through the turbine of the air cycle machine to a pressure close to cabin air pressure, and subse-
quently, the air temperature is reduced.
From the turbine outlet, the air flows through the condenser heat exchanger where it is used as a coolant for the water sep-
aration loop.
The air temperature at the PACK discharge can be adjusted by opening or closing the temperature control valve. The tem-
perature control valve modulates the hot air flow which by-passes the air cycle machine between the primary heat exchang-
er inlet and the air cycle machine turbine outlet.
The ram air is supplied upstream of the dual heat exchanger by the ram air system. It then flows through the dual heat ex-
changer and is collected by the plenum.
On ground static aircraft operation, the ram air flow is generated by the suction effect of the air cycle machine fan. This
suction closes the plenum check valve. Whenever dynamic air is available at ram air inlet, the plenum check valve opens,
and the air cycle machine fan is by-passed; the ram air is then driven by the total pressure available at ram air inlet.
Upon leaving the plenum, the air is ducted towards the dual pre-cooler heat exchanger, then ducted overboard.
FLOW CONTROL VALVES
Flow control valves (FCVs), are used to control the mass airflow through the PACK and TRIM AIR system. The flow con-
trol valves are electrically controlled, pneumatically operated, modulating shutoff valves. The AIR SOURCE selector on
the AIRCOND/BLEED control panel operate the opening and closing of these valves.
The FCVs are automatically closed when the engine START switch is selected. Shutting down the air conditioning system,
ensures that the air turbine starters (ATS) receive sufficient airflow for starter operation. When the start valve closes, the
air source returns to the previous selection.
C
FO0203
000_002
DUAL HEAT
EXCHANGER
PLENUM
AIR CYCLE
MACHINE
TEMPERATURE
CONTROL VALVE
REHEATER/
CONDENSER
WATER
EXTRACTOR