2.3k likes | 5.28k Views
CFM56-5A/B. Curso Electromecânicos A320 FAM CFM56-5A/B. Ignição. AVISO: Só trabalhar no sistema, 5 min. após o corte de corrente ao circuito. Curso Electromecânicos A320 FAM CFM56-5A/B. IGNITION AND STARTING SYSTEM
E N D
AVISO: Só trabalhar no sistema, 5 min. após o corte de corrente ao circuito.
Curso Electromecânicos A320 FAM CFM56-5A/B IGNITION AND STARTING SYSTEM The ignition system provides the electrical spark needed to start or continue engine combustion. The ignition system is made up of two independent subsystems. Each subsystem includes an ignition box and a spark igniter. The pneumatic starting system drives the engine HP rotor at a speed high enough for a ground or air start to occur. The start system is made up of the start valve and the starter. CONTROL AND INDICATING The Electronic Control Unit (ECU) controls the ignition and starting systems either in automatic or manual mode. The operation of the start valve and of the ignition system is displayed on the ENGINE ECAM page. AUTOMATIC START During an automatic start, the Electronic Control Unit opens the start valve, then the ignition box is energized when the HP rotor speed is nominal. The ECU provides full protection during the start sequence. When the automatic start is completed, the ECU closes the start valve and cuts off ignition. In case of an incident during the automatic start the ECU aborts the start procedure. MANUAL START During a manual start, the start valve opens when engine MANual START pushbutton is pressed in, then the ignition system is energized when the MASTER control lever is set to the ON position. NOTE : there is automatic shut down function in manual mode only for EGT overlimit.
Curso Electromecânicos A320 FAM CFM56-5A/B CRANKING Engine motoring could be performed for dry cranking or wet cranking sequences. NOTE : during cranking ignition is inhibited. CONTINUOUS IGNITION With engine running, continuous ignition can be selected via the Electronic Control Unit either manually using the rotary selector or automatically by the FADEC. SAFETY PRECAUTIONS Safety precautions have to be taken prior to working in this area. WARNING : the Electronic Control Unit sends 115 volts to the ignition boxes, which convert it and send high voltage, high energy pulses through the ignition leads to the igniters. MAINTENANCE PRACTICES To increase aircraft dispatch, the start valve is equipped with a manual override. For this manual operation, the mechanic has to be aware of the engine safety zones. WARNING: MAKE SURE THAT THE IGNITION BOXES ARE DE-ENERGIZED BEFORE WORKING ON THE IGNITION SYSTEM. THE VOLTAGE OUTPUT CAN BE DANGEROUS. DO NOT TOUCH THE ELECTRICAL CONTACTS, THE IGNITION BOXES CAN CONTINUE TO CONTAIN NA ELECTRICAL CHARGE WHEN THEY ARE NOT ENERGIZED.
Curso Electromecânicos A320 FAM CFM56-5A/B IGNITION BOXES - Upper box for system A. - Lower box for system B. The ignition boxes transform 115V-400Hz AC into high voltage (15 to 20 KV), to charge internal capacitors. The discharge rate is of one discharge per second and energy delivered is 1.5 joules. IGNITION LEADS They are of the insulated wire type and fan air cooled in the core area. They transmit electrical energy for ignition sparks. IGNITERS - right igniter for system A. - left igniter for system B. - precautions have to be taken before removal/installation. - an ignition test is available through MCDU menus to verify the ignition circuit, without removing it.
CAIXAS DE IGNIÇÃO: -Circuito de recepção -Rectificador e armazenamento (condensador) -Circuito de descarga Input Voltage: 105-122VAC 380-420 Hz Output Voltage: 1a 5 descargas por seg. de 15-20KV
Fan air introduction Condutor de cobre, envolvido em manga de cobre, manga de metal e exterior de Níquel. Fan air introduction
Sistema A Sistema B Cada canal pode controlar o switch de cada sistema de ignição.
Engine Warning Display Engine Man Start Panel Engine Control Panel System Display
Se N2<50% e EGT>725ºC ECU aborta arranca.
Em Cruise, o impulso remanescente é 1/5 do nominal em Sea Level
Curso Electromecânicos A320 FAM CFM56-5A/B ROTOR ACTIVE CLEARANCE CONTROL SYSTEM (RACC) The Rotor Active Clearance Control system (RACC) is controlled by the FADEC system which maintains HPC rotor blade clearance relative to HPC stator compressor case. The RACC system modulates the fifth stage High Pressure (HP) compressor bleed air into the compressor rotor bore to vary and control the clearances. The air flow to the rotor is mixed with the booster discharge air. By heating the compressor rotor with fifth stage bleed air, the compressor clearances are reduced. This improves the efficiency of the compressor and the overall Specific Fuel Consumption (SFC) of the engine. When the RACC valve is closed, the total air flow through the rotor is from the booster discharge air and the clearances are maximized. As the RACC valve opens, the amount and temperature of the air through the rotor is increased due to the introduction of fifth stage bleed air: then the clearances are closed to optimize performance. Rotor Active Clearance Control Valve The Rotor Active Clearance Control (RACC) valve is a butterfly valve with one inlet port and one outlet port. The valve has a RACC port and a PCR port. It consists of an outer housing, a rotating plate, and an integral fuel powered actuator with dual independent transducers for position feedback. The inlet port receives 5th stage compressor bleed air which is modulated by rotating the plate. The RACC valve outlet port supplies modulated bleed air. The RACC valve is located on the HPC compressor case at 12:00 oclock.
-5A RACC Valve Schematic
-5A RACC Valve Localização #12 horas HPC case
-Queima eficiente -Evita pontos quentes -Respeita normas emissão NOx -Boa capacidade light-up -Nunca provocar Stall
Ceramic Coating Convergente, para acelerar os gases da combustão, aumentando a energia cinética que vai ser convertida em binário no rotor HPT.
Efeito Venturi Importante drenagem dos air seals para evitar condições de fogo.
Curso Electromecânicos A320 FAM CFM56-5A/B AIR SYSTEM The engine air system covers the compressor airflow control, turbine clearance control, transient bleed and cooling. COMPRESSOR AIRFLOW CONTROL To limit compressor surge and to provide good acceleration, the engine is equipped with a Variable Bleed Valve (VBV) system and a Variable Stator Vane (VSV) system. Both systems are fuel operated by the HydroMechanical Unit (HMU) and controlled by the Electronic Control Unit (ECU). VBV SYSTEM The Variable Bleed Valve (VBV) system controls airflow from the LP compressor to the HP compressor by using 12 valves. The VBVs discharge the LP compressor air into the fan air stream to match LP/HP compressor airflow at low speed and transient operations. VSV SYSTEM The Variable Stator Vane (VSV) system controls airflow through the HP compressor by using the first four rows of pivoting vanes. The first stage is called Inlet Guide Vanes (IGV). The VSVs provide aerodynamic matching of the HP compressor stages to prevent engine surge.
Curso Electromecânicos A320 FAM CFM56-5A/B AIR SYSTEM SAFETY PRECAUTION: For Removal operation: - Warning notices must be put to tell persons not to start engine 1(2) and not to set the ENGine FADEC GrouND PoWeR 1(2) ON. - Make sure that engine 1(2) has been shut down for at least 5 minutes. VBV: Variable Bleed Valve. The Variable Bleed Valves are driven by flexible shafts from the master VBV. The master VBV is driven by a fuel gear motor assembly which consists of a positive displacement gear motor and end-of-stroke stop mechanism. The motor converts pressurized fuel into rotary shaft power driving the gear reduction stage of the VBV and master ballscrew actuator assembly through the VBV stop mechanism. CAUTION (Removing the VBV stop mechanism and gear motor): use a second wrench to apply countertorque to the nipple when you disconnect/connect hydraulic lines on nipples. Take care not to damage the protecting boot on the VBV fuel gear motor assembly during removal. CAUTION (Installing the VBV stop mechanism and gear motor): be careful not to cause damage to the protecting boot on the VBV fuel gear motor assembly during installation. Keep the motor perpendicular to the mounting surface to prevent damage to the splines, when you install the VBV fuel gear motor on the VBV stop mechanism. Use a second wrench to apply countertorque to the nipple when you disconnect/connect hydraulic lines on nipples.
Entre o strut 10 e 11 Evita Stall em condições de baixa velocidade. O LPC fornece um caudal demasiado elevado para o HPC aceitar.
Curso Electromecânicos A320 FAM CFM56-5A/B VBV AND MASTER BALLSCREW ACTUATOR ASSEMBLY RIGGING: During installation of the VBV and master ballscrew actuator assembly, use a special wrench, ratchet-dual purpose VBV man control, to close the VBV door until it contacts the scoop (refer to AMM 75-31-50). VBV AND BALLSCREW ACTUATOR ASSEMBLIES RIGGING: During installation of a VBV and ballscrew actuator assembly, set the VBV door in closed position using the wrench, ratchet-dual purpose VBV man control (refer to AMM 75-31-50). VBV FEEDBACK ROD RIGGING: The VBVs must be rigged in the closed position before adjusting the feedback rod. To adjust the feedback rod with the RVDT, check that the sensor arm is well aligned with the sensor mark. If not aligned, loosen the adjustment nut, remove the bolt and set the assembly by turning the clevis by half-turns until the sensor arm is aligned with the mark. (Refer to AMM 75-31-70)