Operation Manual / Power2 850-M / 4 Product description
1 Introduction / 1.4 Layout and function of the high-pressure stage
© Copyright 2020 ABB. All rights reserved.
HZTL4061_EN
Rev.D
March 2020
Mode of operation of the high-pressure stage (Power2 HP)
Fig. 5: Power2 HP 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 high-pressure stage (Power2 HP) 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 high-pressure stage (Power2 HP) shown in the illustration
function of the high-pressure stage
, the exhaust gas flows through the gas inlet cas-
ing (06) and the nozzle ring (07) and reaches the turbine (08). The HP turbine uses the en-
ergy contained in the exhaust gas to drive the rotor. The exhaust gases then flow through
the gas outlet casing (05) and the exhaust gas pipe connected to it before reaching the tur-
bine of the low-pressure stage (Power2 LP).
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 HP compressor wheel (02) connected to the shaft sucks in the precompressed air or an
air/gas mixture from the low-pressure stage (25) through the air suction branch (01). The air
is compressed further in the HP compressor and the downstream diffuser (03) and sub-
sequently supplied to the charge air cooler via the compressor casing (10).
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