14-02-2013, 03:26 PM
Exhaust Gas Turbocharger
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Characteristics of the TCR Series
Exhaust Gas Turbocharger
Economic operation of modern engines without exhaust gas
turbochargers is inconceivable. MAN Diesel turbochargers
are equally tried and tested with marine main engines, auxiliary
engines and in stationary systems under the most various operating
conditions. Reliability, easy maintenance and long inspection
intervals have been confirmed through-out decades
of experience.
Principles of Exhaust Gas Turbocharging
The exhaust gas turbochargers of the TCR Series are intended
for constant and pulse pressure turbocharging.
Constant pressure turbocharging:
With constant pressure turbocharging, the engine exhaust gases
flow into a common exhaust manifold, are accumulated there
and flow with minor pressure fluctuations to the exhaust turbine.
Performance Characteristics
The following operating lines are distinguished:
• Generator curve (constant engine speed),
• Standard propeller curve (variable engine speed),
• Propeller curve at reduced engine speed (high torque),
• Combinator curve (combination of generator and propeller curve),
• as well as vehicle engine curve.
Regardless of the engine’s application purpose, a safety margin
of all possible operating points to the surge line of the
compressor is always required. This is ensured by the respective
dimensioning of the compressor
Turbine Wheel
The turbine wheel, which is precision casted, consists of a
high temperature nickel-based alloy and is connected to the
rotor shaft by means of friction welding. CFD simulations, FEM
calculations, as well as extensive operational testing with testbed
load measurement ensure maximum reliability.
Bearing Casing
The bearing casing is manufactured of cast iron with spheroid
graphite. It contains the distribution ducts for the lube oil
which is also used for cooling of the casing.
For special applications, e.g., for gas engines with high exhaust
gas temperatures, water-cooled bearing casings can
be provided.
Silencer with Air Filter
Exhaust gas turbochargers for marine engines, as a standard,
are equipped with silencers that are surrounded by a filter mat.
Silencer characteristics:
• High turbocharger efficiency due to low pressure loss,
especially at high air-flow,
• Effective sound level reduction,
• Low air-flow velocity at the silencer intake,
• Integrated cleaning device for compressor.
The completely new developed silencer casing dampens the
sound immission to less than 105 dB(A).
Air filter mat characteristics:
• The effective filtration widely keeps the compressor, diffuser
and charge-air cooler free from dirt particles,
• Easy replacement and installation,
• In case filter particles are drawn in, there is no danger of
damage to any leading edges of the compressor,
• Cleaning of the air filter mat is required only every 250
operating hours (approx.).
Containment Safety
With modern diesel engines, turbochargers are one of the
components that are subject to the highest loads. The high
speeds of turbocharger rotors lead to high centrifugal forces
and high component temperatures at the same time.
All assemblies of a MAN Diesel turbocharger are designed to
provide optimal burst protection. Extensive calculations and
operational testing ensure maximum safety.
MAN Diesel turbochargers comply with the required containment
safety according to the regulations of the classification societies
so that particles cannot be expelled in case of damage.