We know that diesel engine is effective for peak load power plant. A diesel engine can go to full load within 5 minutes but a steam plant unit might need over 12 hours to go to loading. With this advantage diesel engine has its own limitation that it is very uncertain and not reliable. There is always prone to some problems or difficulties. You can stop a good running engine and then might fail to restart it – some problem is likely to occur.
So care should be taken to start, stop, run, loading, unloading & specially preserving preserve a diesel engine.
Start and stop procedure of diesel engine with different fuels.
However, if the engine for some reason is started and stopped on diesel oil (LFO), the engines should be operated at high load and on diesel oil for at least 30 minutes before they are stopped. This will secure that there is only diesel oil in the system.
Diesel Engine low load running and idling time.
DIESEL and HFO Engine might run in low load or without load(idle), but there is some restriction to this type of running operation. Things should do according to the engine manufacturers instruction.
As example -for Wartsila 20 V32 Engine running idle.
If the engine has been idling for more than 5 minutes, high load running (minimum 70%) must be followed for minimum 60 minutes to clean up the engine.
- Recommended idling time: 3–5 minute.
- Maximum idling time: 30 minute.
Maintenance and calibration of engine safety automation system –
The speed fluctuations in diesel engine is dangerous as per mechanical perspective. Only 15% to 19% high to nominal speed is allowed. Say a 75o RPM engine has safety shut down on 840 RPM and auto shut down on 880 RPM. In case of cooling system – jacket water cooling of diesel engine is important. The normal jacket water cooling temperature is 85°C to 100°C , and for 110°C there will be direct shut down of engine. Also lower cooling water temperature will led in to normal shut down.
There are three automatic control modules in wartsila w20 v32 engine. They are namely ESM – Engine safety module, Dedicated to fundamental safety of engine like over speed, lube oil low pressure etc. MCM – Main control module, Basically speed controller of engine and also controls start stop of engine. PDM – Power distribution module, Supply power to ESM, MCM and also other sensors includes in automation system.