1.7.3 AIR INLET SYSTEM OPERATION - 9HA GAS TURBINE -COMBINE CYCLE POWER PLANT OPERATION

1. SYSTEM OPERATION

1.0 General

The gas turbine software controls automatically all the devices of this system.

1.2 Start-up

Initial state before start up is as follow:
· Air filter clean air path, inlet duct and inlet plenum clean, free of water, dust, and FOD
· Filter elements of each stage correctly installed to avoid any air by-pass
Housing and duct correctly assembled with gaskets to avoid air bypass
Access doors and hatches closed
· Filter Housing implosion doors closed
· Anti-icing/Bleed-Heating system operational, correctly installed to allow free expansion
· Electrical supply ON
· Sensors and transmitters functional
· Speedtronic operational

Start-up procedure:

• All access doors should be fully closed
• The by-pass doors should be closed.
• Heating cables should be ON
• Speedtronic should be operational and at initial state
• Control panels should be powered on

The filter housing is a static system with no need of start-up instruction. As soon as the GT is ON, inlet air is going through the filtration system, what makes it operational. The filtration system start with the GT.

1.3 Normal Operation

Continuous measurement of inlet pressure drop which increases with fouling of filters. For each filtration stage, an alarm signal will be initiated when final pressure drop level recommended for filters replacement will be reached.

1.4 Shut-Down

No specific instruction is needed for filtration system normal shutdown. It occurs when the GT is turned OFF.

1.5 Manual Operation

1. Before GT Start-Up

To be checked :

· Filter housing : airtightness of door seals, by-pass doors and between all modules

· Electrical equipment : lights and warnings

· Control of sensors : calibration of sensors and transmitters

· Filter assembly : correct assembly of coalescers, prefilters and final filters, no final filters by-pass

· General checks : no risk of foreign object damage

     2. During  Normal  Operation

The pressure drop increase due to filter fouling should be controlled. If the pressure drop is too high an alarm signal is initiated and the filters should be replaced.

Insect screen, AI coils system, BH manifold, by-pass doors and especially filter elements should be checked to detect any potential damage.

During normal operation, pressure transmitters and dew point transmitters calibration shall also checked.

1.6  FILL  UP  AND  DRAINAGE

The inlet system use only water with anti-freeze as heating fluid in the AI/Heater coils system. Fill up or drainage of coils will be part of the complete AI loop commissioning and maintenance operation.

A draining system of modules floors is provided. Water retention (if any) inside the filter hoes should be identified during filter inspection. Draining system shall be then improve to resolve the water retention issues.

1.7.4 SYSTEM TECHNICAL DATA/ALLOWABLE LIMITS

1.0 PRESSURE DROP

Differential pressure drop measurement is performed at the outlet of the filter housing by two pressure drop transmitters (96 TF-1/2). Global air inlet filter pressure drop value is indicated through a numerical signal to the GT control panel. In case of very high pressure drop:

An alarm is generated after a time delay of 2 sec when the pressure drop reaches 1500 pa.

A GT Fast Run back followed by a GT Shutdown if necessary is performed after a time delay of 2 Sec  at 2100Pa. At 2300Pa, the implosion doors will open as electromagnets will be unpowered.