WÄRTSILÄ 46DF, Product Manual

Page: 12 / 242

1.2.2 Output limitations due to gas feed pressure and lower
heating value
Fig 1-2 Derating of output for gas feed pressure and LHV
MJ/Nm3
28 30 32 34 36 KGAS
kPa a 599 580 564 552 542 1
338 326 317 309 303 0,5
NOTE
1) Values given in m3 are valid at 0°C and 101.3 kPa.
2) The values for gas feed pressure are valid at the engine inlet i.e. after the gas
regulating unit.
3) Receiver pressure requirement is dependent on humidity. Receiver pressure
level influences on the required gas feed pressure. These values are valid for the
humidity up to 30g water/kg dry air.
4) Fuel gas feed pressure is not allowed to decrease from the level given for 36
MJ/Nm3 with LHV higher than 36 MJ/Nm3.
5) Gas fuel lower heating value refers to the gas quality at the engine inlet. This
may differ from the average gas quality in LNG tank.
6) No compensation (uprating) of the engine output is allowed, neither for gas feed
pressure higher than required in the graph above nor lower heating value above
36 MJ/Nm3.
7) If the gas pressure is lower than required, a pressure booster unit can be installed
before the gas regulating unit to ensure adequate gas pressure. If pressure arise
is not possible the engine output has to be adjusted according to above.
1-4 DBAD209883
Wärtsilä 46DF Product Guide 1. Main Data and Outputs