In dual fuel low exhaust will gas trip the engine – once it’s running in diesel we understand that further low exhaust will shutdown the engine – (for a WECS control system). Don’t know if Unic has another control logic.
We don’t have the Unic control, so i’m looking forward to a solution.
Sometime at startup the temperatures are very low, so if the deviation starts these temp are sometime below the deviation and the engines trips. If it was an alarm you can still do something about it.
Have you requested a Wartsila tech to troubleshoot and tune. Your reply made me think of something – if you are a dual fuel facility – are you sure it’s not tripping on reverse power. We’ve tripped on reverse power at start up when a cylinder goes cold and the governor is unable to respond quick enough. Ben Linqvist of Wartsila was able to reset the governor table in the WECS and was able to stop the trip.
Are you questioning what tripped the unit during startup or should a high exhaust temperature deviation trip the unit during startup?
On our W20V34SG machines with either WECs8000 or UNIC we do experience shut downs during startup for “SHD, Low Exh gas temp. cyl xxA/B. I’m not sure if the shut down is a deviation from average temperature or a lower than expected rate of temperature rise.
You should be able to review either your Event list on the WOIS or the EDL log in WECsPlorer to see what is the primary cause of shutdown.
We have experienced some issues with the fuel flushing or the control system delay for fuel flushing in the past on the W20V34SG machines with both WECs8000 or UNIC . The exhaust temperatures near the main fuel gas venting valve does not rise quickly after a 48 hours or longer without operating the engine.
In some cases the venting valve was not opening due to either the solenoid valve failure or the actuator was leaking air and needed to be rebuilt. In other cases the fuel pressure and or the main fuel vent valve open duration needed to be increased to vent the engine fuel system a little more.