Fig. 3: Compressor Wheel Cooling - ABB HT846914 Operation Manual

Operation Manual / A150-M56/66/57/67 - A155-M..
1 Introduction / 1.4 Layout and function of the turbocharger
Mode of operation
The turbocharger is a turbomachine and consists of the following main components:
¡
Turbine
¡
Compressor.
These components are installed on a common shaft and form the rotor.
The exhaust gases of the internal combustion engine flow through the turbine casing (10)
and the nozzle ring (09) onto the turbine (07). The turbine (07) uses the energy contained in
the exhaust gas to drive the rotor and, hence, the compressor wheel (13). The exhaust gases
then reach the atmosphere through the exhaust gas pipe connected to the gas outlet
flange (08).
The compressor wheel (13) sucks fresh air through the air suction branch or the filter silen-
cer (01). In the compressor wheel (13), the energy required for building up the pressure is
transferred to the air. By flowing through the diffuser (03) and the compressor casing (02),
the air is compressed further and is then directed to the engine cylinders.
The rotor runs in two radial plain bearings (06) which are located in the bearing casing (04)
between the compressor and turbine. The axial thrust bearing (05) is located between the
two radial plain bearings.
The plain bearings are connected to a central lubricating oil duct which is normally supplied
by the lubricating oil circuit of the engine. The oil outlet always lies at the deepest point of
the bearing casing (04).
Function of the compressor wheel cooling
Fig. 3: Compressor wheel cooling
Depending on the application of an A100 radial turbocharger, the turbocharger is equipped
with compressor wheel cooling. With compressor wheel cooling, after the compressor air
has cooled down by passing through the charge air cooler on the engine side, it is supplied
to the turbocharger for cooling the compressor wheel. Cooling of the compressor wheel is
compulsory to ensure the reliability and replacement intervals for the relevant operating
conditions. In the turbocharger version with compressor wheel cooling, the cooling air is
supplied through a lateral connection in the bearing casing (X).
In addition, the turbocharger version with compressor wheel cooling is indicated by the tur-
bocharger type (M6..) on the rating plate.
© Copyright 2022 ABB. All rights reserved. HZTL4032_EN Rev.S February 2022