• No results found

PNEUMATIC SYSTEM (CHAPTER – 36)

In document A320 Notes (Page 129-132)

• Bleed air system got 3 different sauces

• APU

• Engines

• Ground cart Engine

• Two different stages

• IP – 7th HP stage

• HP – 10th HP stage, HP valve

• Opens and regulates at 36psi when IP pressure is low

• Spring loaded to close in absence of up stream pressure

• Closer of PRV leads HP valve to close by PRV – HPV sense line

• In flight EEC maintain HPV close by energizing solenoid located on the sense line if

• Engine speed > Idle speed

• Altitude > 15000 ft

• Wing anti-ice close

• Normal pack configuration (2 pack operation)

• In case of low and excessive up stream pressure (closer pneumatically)

• Position indication goes to ECAM via BMC Intermediate pressure valve

• Protects IP stage by reverse flow when HP valve open Engine Bleed valve (PRV)

• HP & IP bleed pressure goes through PRV

• Operates pneumatically, control down stream pressure to 44psi

• Spring loaded to close in up stream pressure is lost

• Position indication goes to ECAM via BMC

• CTS powered by 28VDC via BMC

• Pneumatically Controlled by CTS located in down stream of precooler. CTS operation in TWO modes

• Pneumatically

• Over temp. protection of down stream of precooler by thermostat to reduce PRV flow rate

• Over heat protection of down stream of the precooler

• Controlled close in case of reverse flow

• Electrical Mode

• PRV shut off function solenoid energized by

• Flight deck panel (engine bleed valve P/B select OFF or Fire P/B push)

• BMC if

• Over temperature

• Over pressure

• Leak detected

• Engine starter valve open

• APU bleed set to ON

ENG BLEED Fault LT ON – Down stream of bleed valve hi bleed temp. or pressure

- Wing leak detection

- Engine bleed leak detection - Engine bleed not closed - Pylon leak detection

- If one loop inoperative then other detects fire - Bleed valve not close during engine start - Bleed valve not close with APU bleed ON Switch pressed IN – Bleed valve opens if

- Upstream pressure > 8 psi.

- APU bleed P/B switch OFF or APU bleed valve close

- No on side wing or pylon leak and no over pressure or over temperature has detected - Engine fire P/B not pop out

- Engine start valve closed FAULT

OFF

Pressure transducers

• Located down stream of the PRV (one in each side) to provide ECAM bleed pressure via BMC 1 & 2 and SDAC

• Located down stream of HPV (one in each side) and provides signal to BMCs to monitor HPV and PRV Precooler

• Located in pylon, air to air heat exchanger regulates temp. at 200 °C

• Cooled by fan air and air controlled by FAN AIR VALVE Precooler outlet temp. sensor

• Provide ECAM indication and used to system monitoring via BMC (one for each side) Fan Air Valve

• Controlled by CT (control thermostat) pneumatically located down stream of precooler

• Spring loaded to close in the absence of air pressure APU

• Bleed passes through APU bleed valve, electrically controlled and operated by fuel pressure

• APU bleed valve got priority over engine bleed valves APU Bleed valve

APU BLEED

Fault Lt. ON – APU bleed leak detected (APU bleed valve and cross bleed valve close)

Valv If engine was running own bleed valve opens Vvvvv Sw. pressed IN – APU bleed valve open if

- APU fire P/B not released

- No L/H & APU leak detection (if leak dection on R/H side cross bleed valve closes)

- APU RPM > 95%

- NO shut command Cross Bleed Valve

AUTO SHUT OPEN

AUTO – Open & Close with APU bleed valve Auto open if

- Mode selector auto - APU bleed not close

- Engine Fire P/B not released - No leak inhibition during engine start Manual Mode

OPEN – Valve open CLOSE – Valve close

• Cross bleed valve located in L/H side of the cross bleed duct allows to interconnect engine air systems

• Electrically controlled by 2 motors

• Primary motor – Auto mode

• Secondary motor – Manual mode (can OVRD auto mode) Leak Detection

• Provides to detect over heat in the vicinity of hot air ducts in the wings, pylons and fuselage

• Monitors following zones

• Wing and Packs – Double loop

• Left loop monitors bleed ducts, cross bleed valve and APU check valve

• Right loop monitors bleed ducts and cross bleed valve

• Pylons – Single loop with one sensing element

• APU bleed duct – Single loop

• BMC 1 receive Loop “A” , Eng.1 Pylon and APU loop leak detection signals

• BMC 2 receive Loop ”B”, Eng. 2 Pylon leak detection signals

• BMC 1 & 2 cross talk then via AND logic provide warnings FAULT

ON

Wing leak detection causes

• Bleed valve of the related side to close automatically

• Associated Fault Lt. located on the air-condition panel comes ON

• Cross bleed valve closes automatically except engine start

• APU bleed valve goes to close automatically if leak concerns at the left wing except engine start Pylon leak signal causes

• Bleed valve on the related side closes automatically

• Associated Fault Lt. located on the air-condition panel comes ON

• Cross bleed valve closes automatically except engine start APU leak signal causes

• APU bleed valve closes automatically except engine start

• Associated Fault Lt. located on the air-condition panel comes ON

• Cross bleed valve closes automatically except engine start BMC • Monitoring by 2 BMCs

• Bleed pressure

• Bleed Temperature

• Leek detection

• Normal configuration

• BMC 1 – Monitors left side of cross bleed system

• BMC 2 – Monitors right of cross bleed system

• If BMC 1 fails other will monitor except APU and Pylon

• Both BMC fail no aural warning only ECAM message + crosses on system page

• BMC interfaces

• With SDAC to provide ECAM indication

• CFDIU for maintenance data

• Opposite BMC to provide wing loop leak status, bleed parameters

• APU ECU to bleed valve control

• Zone controller

IF one BMC failed monitoring of main parameters kept valid

• HPV

• PRV

• Precooler outlet temp. sensor

• Following ECAM warnings will be avail

• Over pressure

• Over temperature

• Wing leak

• Automatic control of PRV will be lost

• Associated Fault Lt. on air-condition panel lost

• Pylon leak warning for associated engine

• If BMC 1 APU bleed leak warning will be lost

In document A320 Notes (Page 129-132)