Turbine Package Operators Manual
Chapter 1
Turbine Package System Overview
1-25
Turbine Underbase, Enclosure and Air Supply/Exhaust
Systems
Introduction
The underbase forms a structure for mounting the turbine, auxiliary gearbox and associated
systems.
An acoustic enclosure is provided over the turbine, interfacing with the underbase, to reduce
noise levels from the machinery to an acceptable level.
A ventilation system is used to purge the turbine enclosure prior to a start, to cool the turbine
during running and for a period following shutdown, and to ventilate the enclosure should a gas
leak occur. The ventilation air is discharged from the enclosure through the ventilation outlet.
The intake system filters and ducts combustion air to the turbine inlet casing and incorporates a
silencer to reduce noise emissions from the turbine intake.
The exhaust system ducts the exhaust gases from the turbine to atmosphere and incorporates a
silencer to reduce noise emissions
A schematic diagram of the ventilation and combustion air systems is located in this Manual
Volume.
Underbase
A single piece underbase of fabricated steel construction, which incorporates an integral
lubricating oil tank, provides mounting points for the main turbine/gearbox support and the
turbine combustion casing support. Torque reactions from the turbine/gearbox are transmitted
from the fabrication to the foundations through the multiple mounting pads and foundation
bolting.
The underbase incorporates mounting features/points for all the turbine support systems. System
supply, vent, and drain connections are integrated into the main side members of the fabrication.
The underbase also incorporates integral plating on the underside of the fabrication, which forms
a spillage collection feature for any system leakage.
Turbine Acoustic Enclosure
The turbine acoustic enclosure comprises a load bearing framework, with removable paneling
and hinged doors, mounted on the turbine underbase. Sound attenuation is achieved by a
combination of material thickness, acoustic infill and, if required, the provision of an acoustic
skirt.
Ventilation System
The ventilation system draws air from the atmosphere and directs it through ducting and system
components before discharging it back to atmosphere in a safe area.
