Cirrus Design
Section 7
SR22T
Systems Description
P/N 13772-005
7-37
P/N 13772-005
7-37
Air Induction System
Induction air enters the engine compartment through two NACA ducts
located in the lower engine cowls. The air continues to the air boxes
where it is filtered and ducted into the compressor housing where the
compressor wheel, spinning at a high RPM, increases the air pressure
which provides a greater mass of air available to the engine for the
combustion cycle. From the compressor housing, the air is ducted
through the intercoolers where the air temperature is lowered which
further increases the density of the induction air. Downstream of the
intercoolers the airflow joins at the “Y” junction of intake tubes, then
passes through the throttle body and into the intake manifold where it
is divided by the intake pipes flowing to each cylinder.
In the case of filter blockage or induction ice, alternate air can enter
the engine via the alternate air assembly located in the lower front of
the engine and connected to the LH and RH air boxes. Under normal
conditions, the alternate air assembly door is held closed by magnetic
force. If the air induction system should become blocked, suction
created by the engine will open the door and draw unfiltered air from
inside the cowl. When the door opens, a switch opens which causes
an annunciation on the Primary Flight Display to alert the pilot.
Use of alternate air will result in a reduction of engine power due to
lower inlet air pressure and higher air temperature. Additionally loss of
manifold pressure will occur when operating at high altitude and low
RPM where the turbocharger wastegate is closed.
Engine Exhaust System
After leaving the cylinders, exhaust gases flow through the exhaust
collector to the turbocharger turbine housing inlet. The exhaust gas
flow provides turbine wheel rotation then exits through the turbine
housing discharge port and overboard through tailpipes exiting
through the lower cowling.
Engine Fuel Injection
The multi-nozzle, continuous-flow fuel injection system supplies fuel
for engine operation. An engine driven fuel pump draws fuel from the
selected wing tank and passes it to the mixture control valve integral to
the pump. The mixture control valve proportions fuel in response to the
pilot operated mixture control lever position. From the mixture control,
fuel is routed to the fuel-metering valve on the air-induction system
throttle body. The fuel-metering valve adjusts fuel flow in response to
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