Operation Manual / Power2 845-M / Low-pressure stage
7 Periodic maintenance / 7.3 Cleaning turbine and nozzle ring during
operation
© Copyright 2022 ABB. All rights reserved.
HZTL4068_EN
Rev.E
March 2022
7.3.3
Wet cleaning of turbine blades and nozzle ring
Cleaning procedure
The individual phases of the turbine cleaning procedure are shown in the following illustra-
tion.
Fig. 19: Load/time chart
1. Cool down phase
u
Reduction of the engine load to the operating point for turbine cleaning and subsequent
maintenance of the holding time according to the specifications in the following table.
Power2
Gas pulse at
the inlet in the
HP stage
[N/m
2
]
Gas pulse at
the inlet in the
LP stage
[N/m
2
]
Engine load
[%]
Max. gas inlet
temperature
when starting
cleaning
[°C]
Holding time
at reduced
load
[min]
845
9500 ±2500
3200 ±800
25
430
≥
10
Table 18: Operating point for turbine cleaning
Algorithm for the gas pulse
For an optimum cleaning result, the gas pulse adopted when designing the cleaning process
should be set via the control system on the engine side. The algorithm for the gas pulse is
specified in the section
. If this is not possible, the spe-
cified engine load point is to be set as an approximation.
Thermomechanical stress
Due to the thermomechanical stress of the turbine casing, the gas inlet temperature should
not exceed the specified maximum temperature before starting cleaning. If this is the case,
the engine load is to be lowered until the permissible temperature is reached.
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