Curso Electromecânicos A320 FAM CFM56-5A/B 3 AVISO: Só trabalhar no sistema, 5 min. após o corte de corrente ao circuito.
Curso Electromecânicos A320 FAM CFM56-5A/B 4 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 5 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.
7 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.
Curso Electromecânicos A320 FAM CFM56-5A/B 8 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
Curso Electromecânicos A320 FAM CFM56-5A/B 9 Condutor de cobre, envolvido em manga de cobre, manga de metal e exterior de Níquel. Fan air introduction
Curso Electromecânicos A320 FAM CFM56-5A/B 27 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.
Curso Electromecânicos A320 FAM CFM56-5A/B 41 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 44 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.
Curso Electromecânicos A320 FAM CFM56-5A/B 50 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)
Curso Electromecânicos A320 FAM CFM56-5A/B 51 Instalada entre os Strut’s 10 e 11.
Curso Electromecânicos A320 FAM CFM56-5A/B 55 Rev Idle => increase open VBV Reduz desgaste mecânico Abrem mais em condições de gelo ou ingestão de água
Curso Electromecânicos A320 FAM CFM56-5A/B 56 Bad Weather Abertas em baixa rotação, fecham com o aumento da velocidade N1.
Curso Electromecânicos A320 FAM CFM56-5A/B 57 Curso Electromecânicos A320 FAM CFM56-5A/B VSV: Variable Stator Vane VSV ACTUATORS There are two VSV actuators and linkage assemblies, one on each side of the engine. (RH side - channel A) (LH side - channel B) Each VSV actuator is hydraulically actuated by the HMU and position feedback is sent to the ECU by an LVDT contained in the actuator. NOTE: For removal/installation, the actuator rod is set in the extended position which corresponds to the VSV fully closed position. Note that there are no specific rigging tasks because the LVDT defines the actuator position. VSV BELLCRANK ASSEMBLIES NOTE: One unit for each actuator. The bellcrank has pre-rigging rods to provide correct positioning when installed.
Curso Electromecânicos A320 FAM CFM56-5A/B 58 Para optimizar a eficiência do HPC, posicionando o escoamento de ar com o ângulo apropriado. Melhora margem de Stall. #2 #8 horas
Curso Electromecânicos A320 FAM CFM56-5A/B 67 Curso Electromecânicos A320 FAM CFM56-5A/B ACTIVE CLEARANCE CONTROL There are three systems independently controlled by the ECU and actuated from the HMU which provide the engine clearance adjustment and transient bleed. The clearance between the blade tips and the casings is actively controlled in order to optimize engine performance using cooling air to shrink the LP and HP turbine casings. HPTACC SYSTEM The High Pressure Turbine Active Clearance Control (HPTACC) system uses stage 4 and stage 9 HP compressor air to heat or cool the High Pressure Turbine shroud support structure. The shroud support structure temperature is monitored by the ECU using the T case sensors. LPTACC SYSTEM The Low Pressure Turbine Active Clearance Control (LPTACC) system uses fan air for external case cooling of the LP turbine. TRANSIENT BLEED SYSTEM (TBV) The Transient Bleed Valve (TBV) improves the compressor stall margin during transient and start conditions. The Transient Bleed Valve unloads the HP compressor by discharging stage 9 HP compressor air in the LP turbine cavity.
Curso Electromecânicos A320 FAM CFM56-5A/B 71 Curso Electromecânicos A320 FAM CFM56-5A/B HPTACC: High Pressure Turbine Active Clearance Control HPTACC VALVE The HPTACC valve has integrated a dual butterfly valves driven by a single fuel powered actuator. Position feedback to the ECU is provided by a dual channel LVDT installed on the actuator. One butterfly valve controls the flow from the 4th stage compressor bleed while the other butterfly valve controls the flow from the 9th stage compressor bleed. The 4th stage air is mixed with the 9th stage air downstream of the valve. NOTE: On CFM56-5A model, instead of 4th stage, 5th stage is used to HPT Clearance Control.
Curso Electromecânicos A320 FAM CFM56-5A/B 81 Curso Electromecânicos A320 FAM CFM56-5A/B LPTACC: Low Pressure Turbine Active Clearance Control LPTACC VALVE Low Pressure Turbine Active Clearance Control valve is a butterfly valve. The valve consists of an outer housing, a control plate, a linear actuator, 2 RVDT sensors for feedback signals and a butterfly valve actuation. Under control of the PCR pressure applied at its head end and a PC/PB modulated pressure applied at its rod end, the linear actuator moves a rack controlling both the opening and closing of the butterfly valve which regulates the amount of air required for cooling the turbine as a function of the engine operating configuration (engine rating).
Curso Electromecânicos A320 FAM CFM56-5A/B 92 Curso Electromecânicos A320 FAM CFM56-5A/B TRANSIENT BLEED VALVE The Transient Bleed Valve is a butterfly valve driven from the HMU by a fuel powered actuator. Position feedback to the ECU is provided by a dual channel LVDT installed on the actuator. The TBV normal and fail safe position is closed. The TBV controls the air flow from the HP compressor 9th stage to the LP turbine cavity to improve compressor stall margin during start and transient conditions.
Curso Electromecânicos A320 FAM CFM56-5A/B 93 Transient Bleed Valve Melhora Stall Margin durante o arranque e Accel/Decel rápido.
Curso Electromecânicos A320 FAM CFM56-5A/B 97 Pode abrir <80% Abre até N2<80%: -Rápida aceleração -Bodie decel -Flame-out during decel (non- BSV) diminui ar na câmara para não apagar motor. -N2+100 rpm < N2 min -Ps3+3psi < Ps3 dmd