Man VTA - Page 9

Application Functional principle Effect
2. VTA on every turbocharger and power turbine
▪ “Closing” of all VTAs with con-
stant area factor (and thus con-
stant bypass ratio)
▪ In full load range:
“Closing” of the VTA of the
power turbine to throttle the
power turbine output,
“opening” of the VTAs on the
turbochargers to limit the charge
pressure.
▪ At partial load:
“Closing” of the VTA to throttle
the power turbine output, analo-
gous to 1.
▪ Increased power turbine output
and reduced SFOC by increasing
the scavenge air pressure (see
“2-stroke engine” line) and
exhaust gas pressure
▪ Increased turbocharging effi-
ciency at a given power turbine
output, compared with power
turbine control by means of
bypass
▪ Increased turbocharging effi-
ciency at a given power turbine
output – see 1.
Table 6: VTA range of applications on power turbine
Application Functional principle Effect
Plant technology
▪ Compensation of flow rate fluc-
tuations
▪ Closing during a starting opera-
tion
▪ Elimination of control flaps prone
to a high degree of loss
Table 7: VTA range of applications in plant technology
2013-12-04 - de
1 Adjustable turbine nozzle ring (VTA)
1.1 Range of applications
MAN Diesel & Turbo
1
EN-US
7 (38)