MAN B&W L28/32H, Руководство пользователя

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08028-0D/H5250/94.08.12
General
98.20
B 16 01 1
Water Washing of Turbocharger - Turbine
1607517-7.4
Page 1 (2)
The tendency to fouling on the gas side of turbochar-
gers depends on the combustion conditions, which
are a result of the load on and the maintenance
condition of the engine as well as the quality of the
fuel oil used.
Fouling of the gas ways will cause higher exhaust
gas temperatures and higher surface temperatures
of the combustion chamber components and will
also lead to a lower performance.
Tests and practical experience have shown that
radial-flow turbines can be successfully cleaned by
injecting water into the inlet pipe of the turbine. The
cleaning effect is based on the water solubility of the
deposits and on the chemical action of the impinging
water droplets and the water flow rate.
The necessary water flow is dependent on the gas
flow and the gas temperature. Enough water must
be injected per time unit so that, not the entire flow
will evaporate, but about 0.25 l/min. will flow off
through the drainage opening in the gas outlet.
Ensuring that sufficient water has been injected.
Washing time : max. 10 min.
Service experience has shown that the above men-
tioned water flow gives the optimal cleaning effect. If
the water flow is reduced, the cleaning effect will be
reduced or dissappear. If the recommended water
flow is exceeded, there is a certain risk of an
accumulation of water in the turbine casing which
may result speed reduction of turbocharger.
The best cleaning effect is obtained by cleaning at
low engine load approx. 20% MCR. Cleaning at low
load will also reduce temperature shocks.
Experience has shown, that washing at regular
intervals is essential to successful cleaning, as exces-
sive fouling is thus avoided. Washing every week
during operation is therefore recommended.
The cleaning intervals can be shorter or longer
based on operational experience.
The water should be supplied from the fresh water
sanitary system and not from the fresh cooling wa-
ter system or sea water system. No cleaning agents
or solvents need to be added to the water. Water
consumption 1.5-5 l/min.
Water Washing System
The water washing system consists of a pipe system
equipped with a regulating valve, a valve, a 3-way
cock and a drain pipe with a ball valve from the gas
outlet.
The water for washing the turbine is supplied from
the external fresh water system through a flexible
hose with couplings. The flexible hose must be
disconnected after water washing.
By activating the valve and the regulating valve,
water is led through the 3-way cock to the exhaust
pipe intermediate flange which is equipped with a
channel to lead the water to the gas inlet of the
turbocharger.
The water which has not evaporated is led out
through the drain pipe in the gas outlet.