POWER PLANT PW1100G PRESENTATION
(1) INTRODUCTION
The PW1100G engine is an axial flow, dual-rotor, geared fan, variable stator, ultra high bypass ratio power plant. The PW1100G engines power the A319, A320 and A321 aircraft of the Single Aisle New Engine Option (NEO) family. PW1100G engines are available in several thrust ratings. The geared turbo fan engine reduces fuel consumption, air pollution and noise. Each engine comes with a Data Storage Unit (DSU) which is connected onto the Electronic Engine Control (EEC). It provides engine parameters, thus the possibility of changing the thrust rating.
INSTALLATION The power plant installation includes the engine, the engine inlet cowl, the fan cowls, the thrust reverser assemblies and the exhaust nozzle and centerbody. The engine is attached to the pylon by forward and aft mounts to transmit the engine and thrust loads. The pylon connects the engine to the wing structure. The forward engine mount is located on the Compressor Intermediate case. The rear engine mount is located on the Turbine Exhaust Case.
MODULAR CONCEPT
The PW1100G engine assembly modules are: - Fan rotor - Fan and Intermediate Case - Fan Drive Gear System (FDGS) - Low Pressure Compressor (LPC) - Compressor Intermediate Case (CIC) - High Pressure Compressor (HPC) - Gearboxes under engine core - Diffuser and combustor - High Pressure Turbine (HPT) - Turbine Intermediate Case (TIC) - Low Pressure Turbine (LPT) - Turbine Exhaust Case (TEC)
LP ROTOR, HP ROTOR AND COMBUSTION CHAMBER The Low Pressure (LP) rotor comprises a fan driven by the FDGS, the Low Pressure compressor and the LP shaft, all driven by the LP turbine. The speed of the LP rotor is indicated on the ECAM as N1. The fan supplies most of the engine thrust. The air produced by the fan is known as secondary airflow or bypass airflow. To improve the propulsive efficiency and fuel consumption, the FDGS reduces the fan speed thanks to reduction gear mechanism. The 3-stage Low Pressure (LP) compressor supplies air to the engine core. This is primary airflow. The LP compressor rotates at the same speed as the 3 stage LP turbine. The High Pressure (HP) rotor is made up of 8 stage HP compressor driven by two stage HP turbine. The speed of the HP rotor is indicated on the ECAM as N2. The LP and the HP rotors are supported by roller and ball bearings which are lubricated and cooled. The annular combustion chamber is installed between the HP compressor and HP turbine. It has ports for 18 fuel nozzles and 2 igniter plugs.
TRANSFER & ACCESSORY GEARBOXES The accessory gearbox is installed under the core engine and is driven by the HP rotor through the Angle gearbox. The fuel pumps, oil pumps, hydraulic pump, Integrated Drive Generator (IDG) and FADEC alternator are all driven by the gearbox. During engine starting, the air turbine starter rotates the HP compressor through the gearboxes.
PROPULSION CONTROL SYSTEM (PCS) The Propulsion Control System (PCS) regroups the following subsystems: - The FADEC system consists of an Electronic Engine Control (EEC) and a Prognostic Health Monitoring Unit (PHMU), - The Engine Interface Unit (EIU). In order to increase engine reliability and efficiency, the FADEC gives the full range of engine control to achieve steady state and transient engine performances when operated in combination with aircraft subsystems. The EEC controls the operation of the following: - Engine control for thrust setting in Manual and Auto thrust Modes, - Thrust Control Malfunction protection, - Engine airflow control, - Combustor fuel metering valve, - Control and monitoring sensing, - Ignition and starting systems, - Command and monitoring of the thrust reverser system, - Fault detection, isolation, annunciation and transmission to the A/C (BITE). When the engine is running, power for FADEC operation is supplied by a dedicated alternator driven by the gearbox. The PHMU interfaces with the EEC. It monitors the Engine vibrations and the Oil debris.
EIU The EIU is an interface concentrator between the airframe and the corresponding engine. Two EIUs are installed in the A/C. EIU-1 interfaces with Engine 1 and EIU-2 interfaces with Engine 2. The main functions of the EIU are: - To concentrate data from cockpit panels and different aircraft systems to the associated EEC on each engine, - To ensure the segregation of the two engines, - To give to the airframe the necessary logic and information from engine and to other systems (APU, ECS, Bleed Air, Maintenance), - To give to the FADEC system some necessary logic and information from systems (example: flight/ground status). The Fan Cowl latches of the A320 NEO are monitored by proximity switches which send their position signals to the EIU. The EIU transfers signals to the FWC for associated cockpit warnings based on specific logic conditions.
THRUST REVERSER SYSTEM The flight crew manually selects reverse thrust by lifting the latching levers on the throttle control levers. The thrust reverser system comprises of 2 translating sleeves, 10 blocker doors with cascade vanes per engine. The EEC in accordance with the EIU control valves inside the Hydraulic Control Unit (HCU) for deploy and stow sequences. HCU supplies hydraulic power to operate thrust reverser actuators. The SEC computers authorize unlocking of Tertiary Locks. For maintenance or dispatch the reverser system can be inhibited. Reverse thrust is only available on the ground.
OIL SYSTEM The oil system comprises of an Oil tank, oil pumps located within the Lubrication and Scavenge Oil Pump unit (LSOP), Oil Control Module (OCM), filters and heat exchangers. The oil is used to lubricate and cool the bearings, the Fan Drive Gear System (FDGS), gearboxes and accessories. The supply oil, cooled oil and the return oil parameters are monitored for ECAM warnings and indications.
IGNITION AND STARTING SYSTEMS The Engine starting system is used for normal engine starts, in-flight restarts and ground monitoring. The EEC controls the Starter Air Valve (SAV) to supply air to the Starter for initial N2 rotation. Then the EEC controls the ignition for combustion starting. Parameters are displayed on the ECAM during the sequence. NOTE: Note: The SAV has a manual override function
CONTROL AND INDICATING This section will highlight the control panels and indications for the engines. CONTROL PANELS The engines are controlled by throttle control levers which are installed on the center pedestal. They can only be moved manually. For reverse thrust operation, two latching levers let the throttle control levers move rearward into the reverse thrust section. The A320 family aircraft normally operate in the auto thrust mode, when in flight. The autothrust can be disconnected with an instinctive disconnect pushbutton (2 red buttons are installed on the outside of the lever). This lets the engines be controlled in manual thrust mode. The controls for engine starting and shutdown are installed on the center pedestal immediately behind the throttle control levers. The engine MAN START switches are installed on the overhead panel. These switches are used to start an engine during a manual start procedure. They are also used during a dry or wet motoring procedure.
ECAM ENGINE The engine primary parameters are permanently displayed on the upper ECAM. The engine secondary parameters are presented on the lower ECAM ENGINE page when selected or displayed automatically during engine start or a fault. Some engine parameters are permanently displayed on the CRUISE page in flight.
MAINTENANCE/TEST FACILITIES On the maintenance panel, the ENG FADEC GND PWR permits to supply the FADEC system for maintenance tasks, when the engines are not running. The MCDU is used to do PCS tests and for trouble shooting monitored components (computers, sensors, actuators).
SAFETY PRECAUTIONS When you work on aircraft, make sure that you obey all the Aircraft Maintenance Manual (AMM) safety procedures. This will prevent injury to persons and/or damage to the aircraft. Here is an overview of main safety precautions related to the engines. Make sure that all engine danger areas are as clear as possible to prevent damage to the engine, the aircraft or persons in the area. Be careful: The entry corridor will be closed when the engine power is above the minimum. Make sure that you have fire-fighting equipment available. Do not try to stop the fan from turning by hand. After engine shutdown, let the oil tank pressure bleed off for a minimum of 5 minutes before you remove the tank filler cap. If you do not, pressurized oil can flow out of the tank and cause dangerous burns. The engine ignition system is an electrical system with high energy. You must be careful to prevent electrical shock. Injury or death can occur. Do not do maintenance on the ignition system while the engine operates. Make sure that the engine shutdown occurred more than 5 minutes ago before you continue with the maintenance procedure. Make sure that the thrust reverser is deactivated during maintenance. If not, the thrust reverser can operate accidentally and cause injury to personnel and/or damage to the reverser. When opening the engine cowls: o Respect the wind limitations and the opening/closing sequence, o Always secure cowls with the hold-open rods, o Make sure that the slats are retracted and install a warning notice to prevent slat operation.
STORAGE AND PRESERVATION
Storage and preservation procedures must be applied to engines which are not operated. The preservation procedures protect the engine against corrosion, liquid and debris entering the engine, and atmospheric conditions during period of inactivity.