In the condenser, the air is cooled further by the ACM tubine-outlet air.
The air, which comes from the ACM turbine outlet, has a subzero
temperature. This subzero temperature air cools the air in the condenser
down to a sea level dew point of approximately 0 DEG.C (32.00 DEG.F).
This makes sure that the dew point of the air, which is supplied to the
mixer-unit, is lower than +10 DEG.C (+50.00 DEG.F).
The +10 DEG.C (+50.00 DEG.F) dew point will allow a maximum cabin air
humdity without condensation in the mix manifold or cabin supply air
ducting.
The condensed moisture is collected in the water extractor and sprayed on
the ram inlet air side of the main heat exchanger to increase its cooling
efficiency.
After the water extractor, the air passes through the reheater again
where it increases in temperature and then enters the ACM turbine inlet.
In the ACM turbine, the high pressure air expends its kinetic energy. The
temperature and the pressure decresase. This will cause additional
condensation during ground operation and low altitude flight operation.
This condensation will occur as snow.
The condenser is a tubular heat exchanger with a tube to tube distance,
which is large enough, to prevent the snow from clogging the condenser.
The final pack temperature regulation takes place by mixing the ACM
by-passed air with the turbine outlet air.
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**ON A/C 001-003, 051-054,
To achieve the zone demanded pack discharge-temperature, the pack controller modulates the by-pass valve and the ram air inlet and outlet doors in a predetermined sequence. The sequence is a compromise between a minimized ram air flow while also maintaining adequate heat transfer rates and satisfactory pack air flow. Additionally the by-pass valve always maintains a minimum ACM flow to keep the ACM idling during all operations. In a full cooling mode, the ram air inlet and outlet doors are fully open and the turbine by-pass valve is fully closed. In a full heating mode, the ram air inlet and outlet doors are nearly closed and the by-pass valve is fully open. Between these two extreme conditions, the above mentioned schedule is in effect. In the mixer unit, the pack discharge air is mixed with the cabin recirculation air. The combined air flow supplies the zone ducts where hot trim air is added individually for each of the three zones. The air flow demand is selected by the flight crew with the flow selector which allows a flow setting of 80%, 100% and 120%. The zone controller manipulates the flow between 80% and 100% if the zone duct temperature is limited at its high or low value. It transmits the determined flow demand to the pack controllers which modulate the flow servo of the flow control valve.
R **ON A/C 004-049, 055-099, 101-149, 151-199, 201-299,
To achieve the zone demanded pack discharge-temperature, the pack controller modulates the by-pass valve and the ram air inlet doors in a predetermined sequence. The sequence is a compromise between a minimized ram air flow while also maintaining adequate heat transfer rates and satisfactory pack air flow. Additionally the by-pass valve always maintains a minimum ACM flow to keep the ACM idling during all operations. In a full cooling mode, the ram air inlet doors are fully open and the turbine by-pass valve is fully closed. In a full heating mode, the ram air inlet doors are nearly closed and the by-pass valve is fully open. Between these two extreme conditions, the above mentioned schedule is in effect. In the mixer unit, the pack discharge air is mixed with the cabin recirculation air. The combined air flow supplies the zone ducts where hot trim air is added individually for each of the three zones. The air flow demand is selected by the flight crew with the flow selector which allows a flow setting of 80%, 100% and 120%.
R 1EFF : 001-049, 051-099, 101-149, 151-199, 1 21-60-00Page 31 1201-299, 1Aug 01/05 1 1 1CES 1
The zone controller manipulates the flow between 80% and 100% if the zone
duct temperature is limited at its high or low value. It transmits the
determined flow demand to the pack controllers which modulate the flow
servo of the flow control valve.
R
R **ON A/C 301-399,
To achieve the zone demanded pack discharge-temperature, the pack
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