ABB HT608780, Operation Instructions Manual

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Operation Manual / Power2 850-M / 4 Product description
1 Introduction / 1.3 Layout and function of the low-pressure stage
© Copyright 2020 ABB. All rights reserved. HZTL4061_EN Rev.D March 2020
Mode of operation of the low-pressure stage (Power2 LP)
Fig. 3: Power2 LP diagram
Power2 Two-stage turbocharging 21 HP compressor
Power2 LP Low-pressure stage 22 HP turbine
Power2 HP High-pressure stage 24 LP turbine
A Exhaust gas inlet from internal combus-
tion engine 25 LP compressor
B Exhaust gas outlet 26 Intercooler
C Air or air/gas mixture inlet
D Air or air/gas mixture outlet and supply
to the charge air cooler - - - Not included in the ABB scope of
delivery
The low-pressure stage (Power2 LP) is a turbomachine and its main components are a tur-
bine and a compressor. These components are installed on a common shaft and form the ro-
tor.
In the low-pressure stage (Power2 LP) shown in the illustration (see Fig. 2: Layout and func-
tion of the low-pressure stage → 6) , the exhaust gas coming from the high-pressure
stage (Power2 HP) flows through the gas inlet casing (06) and the nozzle ring (07) and
reaches the turbine (08). The LP turbine uses the energy contained in the exhaust gas to
drive the rotor. The exhaust gases then reach the atmosphere through the gas outlet cas-
ing (05) and the exhaust gas pipe connected to it.
The rotor runs in two radial plain bearings, which are located between the compressor and
the turbine. The axial bearing is also in the form of a plain bearing. 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 lies at the deepest point of the bearing casing (09).
The LP compressor wheel (02) connected to the shaft sucks in fresh air or an air/gas mixture
through the filter silencer (01) or the air suction branch. The air is compressed in the LP com-
pressor and the downstream diffuser (03). The compressed air is passed on to the inter-
cooler (26) via the compressor casing (10). The air is cooled in the intercooler (26) and sub-
sequently supplied to the HP compressor (21).
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