air conditioning systems Flashcards
(34 cards)
the human body is not capable of withstanding the cold temperatures and lack of oxygen at these altitudes. if exposed to these conditions, a person would soon succumb to problems such as ________ and __________, eventually leading to unconsciousness and death
the human body is not capable of withstanding the cold temperatures and lack of oxygen at these altitudes. if exposed to these conditions, a person would soon succumb to problems such as HYPOXIA and HYPOTHERMIA, eventually leading to unconsciousness and death
air conditioning air supplies on commercial aircraft: (4)
- gas turbine compressors
- engine driven blowers
- APU compressors
- ambient ram air inlets
the major components of gas turbine beed air conditioning systems: (6)
- air selector valves from engine/APU
- isolation and non-return valves
- air conditioning packs
- mixer chambers
- distribution systems
- recirculation fans
air conditioning. the cooling packs are controlled by ________-pneumatic pack valves
the cooling packs are controlled by ELECTRO-pneumatic pack valves
air conditioning. the pack valves are opened initially or closed by switches on the pilots ________ panel
air conditioning. the pack valves are opened initially or closed by switches on the pilots OVERHEAD panel
air conditioning. each cooling pack supplies cold air to the main ____________ manifold
air conditioning. each cooling pack supplies cold air to the main DISTRIBUTION manifold
air conditioning. cold air is ducted through the _______ system
air conditioning. cold air is ducted through the GASPER system
air conditioning pack valves. they also meter the airflow to the pack. when the APU is supplying the air, the flow rate is _________
air conditioning pack valves. they also meter the airflow to the pack. when the APU is supplying the air, the flow rate is INCREASED
air conditioning pack valves. the valves are ___________ operated and _____________ controlled
air conditioning pack valves. the valves are PNEUMATICALLY operated and ELECTRICALLY controlled
when the engine low pressure stage cannot supply the required amount of air, the pneumatic system will automatically open the engine _____ pressure stage to satisfy the needs of the air conditioning system
when the engine low pressure stage cannot supply the required amount of air, the pneumatic system will automatically open the engine HIGH pressure stage to satisfy the needs of the air conditioning system
overheat protection. if the ACM (air cycle machine) compressor _________ overheat switch, or the ACM _______ inlet overheat switch are actuated, the pack valve will close. the air cycle machine will then stop.
overheat protection. if the ACM (air cycle machine) compressor DISCHARGE overheat switch, or the ACM TURBINE inlet overheat switch are actuated, the pack valve will close. the air cycle machine will then stop.
cold air units/air cycle machines. the hot air is cooled in the ________ heat exchanger and enters the cold air unit via the _____ inlet of the compressor and is compressed by the action of the compressor ________ and passes through the secondary heat exchanger which dissipates a large proportion of the heat produced by compression
cold air units/air cycle machines. the hot air is cooled in the PRIMARY heat exchanger and enters the cold air unit via the AXIAL inlet of the compressor and is compressed by the action of the compressor IMPELLER and passes through the secondary heat exchanger which dissipates a large proportion of the heat produced by compression
cold air units/air cycle machines. the air also _______ in passing through the turbine wheel; the pressure drop causing further _______ of the air.
the heat energy extracted is converted into __________ energy by the turbine
cold air units/air cycle machines. the air also EXPANDS in passing through the turbine wheel; the pressure drop causing further COOLING of the air.
the heat energy extracted is converted into MECHANICAL energy by the turbine
cabin humidity control. on relatively _____ flights at high altitude, the relative humidity in the cabin is maintained at a comfortable level by ___________ of moisture from furnishings, clothing, etc. and humidifiers are not normally provided.
however, aircraft which normally undertake long flights at high altitudes may be provided with humidifiers to maintain the relative humidity at about __%
cabin humidity control. on relatively SHORT flights at high altitude, the relative humidity in the cabin is maintained at a comfortable level by EVAPORATION of moisture from furnishings, clothing, etc. and humidifiers are not normally provided.
however, aircraft which normally undertake long flights at high altitudes may be provided with humidifiers to maintain the relative humidity at about 30%
cabin humidity control. when humidification is required, the water control is opened either manually or automatically, and the water jet impinges at _____ angles on the high pressure ___ jet which is also operating
cabin humidity control. when humidification is required, the water control is opened either manually or automatically, and the water jet impinges at RIGHT angles on the high pressure AIR jet which is also operating
operation of three wheel air cycle machine system. three wheel air cycle machines, or cold air units, incorporate a ___ which is used to induce airflow across the heat exchangers.
this allows what is basically a ________ cooling system to function of the ground when ram air cooling for the heat exchangers is not available
operation of three wheel air cycle machine system. three wheel air cycle machines, or cold air units, incorporate a FAN which is used to induce airflow across the heat exchangers.
this allows what is basically a BOOTSTRAP cooling system to function of the ground when ram air cooling for the heat exchangers is not available
operation of three wheel air cycle machine system. ____________ is a technique though which something is brought into the desired state through its own action. in the case of the air cycle machine, the hot air is cooled through its own action
operation of three wheel air cycle machine system. BOOTSTRAPPING is a technique though which something is brought into the desired state through its own action. in the case of the air cycle machine, the hot air is cooled through its own action
recirculation fan. the fan is an _____ vane type fan. it is fitted within the recirculation air ducting and draws used conditioned air from the cabin. it is placed downstream of the check valve.
the fan drives the cabin air to the mixer where it is mixed approximately __% fresh air to 40% recirculated cabin air, before returning to the cabin
recirculation fan. the fan is an AXIAL vane type fan. it is fitted within the recirculation air ducting and draws used conditioned air from the cabin. it is placed downstream of the check valve.
the fan drives the cabin air to the mixer where it is mixed approximately 60% fresh air to __% recirculated cabin air, before returning to the cabin
ozone converters. atmospheric ozone is separated out by passing through the ___________ stages of the engines, the air conditioning packs and the ozone converters
the ozone separates out further when in contact with air ducting within the aircraft, interior surfaces and the aircrafts recirculation system
the ozone converter separates out the ozone and by the ________ action of the substance contained within the converter (noble metals such as __________) converts the ozone to oxygen
a modern ozone converter is capable of converting up to __% of the ozone entering it to oxygen and has an average life of approximately _____ flying hours
ozone converters. atmospheric ozone is separated out by passing through the COMPRESSOR stages of the engines, the air conditioning packs and the ozone converters
the ozone separates out further when in contact with air ducting within the aircraft, interior surfaces and the aircrafts recirculation system
the ozone converter separates out the ozone and by the CATALYTIC action of the substance contained within the converter (noble metals such as PALLADIUM) converts the ozone to oxygen
a modern ozone converter is capable of converting up to 95% of the ozone entering it to oxygen and has an average life of approximately 12000 flying hours
description and operation of displacement blower system. provided the spill valves are selected to AUTO, a ___ ____ selection will _______ the mass flow controller, _____ the temperature control valve and bring the spill valves under control of the cold air duct pressure and temperature switches
description and operation of displacement blower system. provided the spill valves are selected to AUTO, a MAX COOL selection will ISOLATE the mass flow controller, CLOSE the temperature control valve and bring the spill valves under control of the cold air duct pressure and temperature switches
mass flow control and the spill valve. each blower is capable of maintaining air conditioning and pressurisation of the cabin at ________ altitude.
therefore when both blowers are operating normally, the excess air supplied must be _______ off.
excess air is spilled off by opening or closing a _____ valve
mass flow control and the spill valve. each blower is capable of maintaining air conditioning and pressurisation of the cabin at CRUISING altitude.
therefore when both blowers are operating normally, the excess air supplied must be SPILLED off.
excess air is spilled off by opening or closing a SPILL valve
mass flow control and the spill valve. the spill valves are __________ operated and may be controlled as follows:
- directly via ___ switches on a control panel in the control cabin
- automatically via the ____ ____ _________ which senses the mass flow through the cabin delivery duct
- automatically via _________ switches and a ___________ switch which senses pressure and temperature in the ducting
mass flow control and the spill valve. the spill valves are ELECTRICALLY operated and may be controlled as follows:
- directly via TWO switches on a control panel in the control cabin
- automatically via the MASS FLOW CONTROLLER which senses the mass flow through the cabin delivery duct
- automatically via PRESSURE switches and a TEMPERATURE switch which senses pressure and temperature in the ducting
mass flow controller. the mass flow controller contains a _________ which responds to ________ pressures. duct pressure is applied below the diaphragm and venturi throat pressure above it.
should the flow rate increase above a pre set value, the lower pressure in the venturi will cause the diaphragm to deflect _______ completing the electrical circuit to open the spill valve and ________ the flow
should the flow rate ________ below the pre set vale, the diaphragm will deflect __________, decreasing the amount of air being spilled
mass flow controller. the mass flow controller contains a DIAPHRAGM which responds to VENTURI pressures. duct pressure is applied below the diaphragm and venturi throat pressure above it.
should the flow rate increase above a pre set value, the lower pressure in the venturi will cause the diaphragm to deflect UPWARDS completing the electrical circuit to open the spill valve and DECREASE the flow
should the flow rate DECREASE below the pre set vale, the diaphragm will deflect DOWNWARDS, decreasing the amount of air being spilled
equipment cooling systems. equipment cooling occurs as long as _________ _____ is available
loss of airflow due to failure of an equipment cooling fan causes __________ heat to activate a thermal switch, illuminating the respective equipment cooling ___ light. selecting the _________ fan will restore airflow past the switch and extinguish the OFF light
equipment cooling systems. equipment cooling occurs as long as ELECTRICAL POWER is available
loss of airflow due to failure of an equipment cooling fan causes INCREASING heat to activate a thermal switch, illuminating the respective equipment cooling OFF light. selecting the ALTERNATE fan will restore airflow past the switch and extinguish the OFF light
