Here Are The Change Over Questions And Answers Which Will Help You To Understand So Many Things –
Question: What Do You Mean By Change Over? Why It Is Required On-board?
Answer: Changeover Of An Engine Is Related To Change The Fuel Oil On Which It Is Operating. It May Be From Diesel Oil To Heavy Or Vice Versa. Due To Greater Cost Of Diesel Oil It Is More Economic To Run Engine On Heavy Oil. But During Long Port Stay Or Where Environmental Legislation Requires The Use Of Low Sulphur Fuels, Diesel Oil Is Used. Hence Engine Often Requires Changing Over From One Type Of Fuel To The Other.
Question: Is There Any Difference In Change Over Procedure For An Engine With Mixing Column And An Engine Without It?
Answer: Yes, There Are Some Differences In The Change Over Procedures For An Engine With A Mixing Column And An Engine Without Mixing Column.
Question: What Are The Steps Involved During Change Over From Diesel Oil To HFO For A Running Engine?
Answer:
Engines Without Mixing Column
1. Heavy Oil Is Heated To 75 Degree C In The Heavy Oil Service Tank. 2. By Means Of Thermostatic Valve In The Steam Line Or Manual Control Of Viscosity Regulator, Diesel Oil Is Heated To About 60 Degree C. This Pre Heating Should Be Regulated With A Temperature Rise 1-2 Degree C/minute. 3. Reduce Engine Load To Harbor Full And Change Over To HFO. 4. Now Raise The Temperature Of HFO At A Rate Of 1-2 Degree C/minute To The Proper Service Temperature Of The HFO. 5. Maintain The Service Temperature And Raise The Engine Load Gradually.
Engines Fitted With Mixing Column.
1. With Mixing Tank Change Over From Diesel Oil To Heavy Oil May Be Done At Full Engine Rpm. 2. Start Circulating Pump Of Mixing Tank. 3. Set Change Over To Heavy Fuel Oil. 4. Open Steam Supply To The Pre-heater.
Question: What Are The Steps Involved In Change Over From Heavy Oil To Diesel Oil For Running Engine?
Answer:
Engines Without Mixing Column
1. Cutoff The Stem Supply To Pre-heater. 2. Reduce Engine Load To Harbor Full. 3. As The Heavy Oil Temperature Drops By 5 Degree C. 4. Change Over To Diesel Oil. If Temperature Suddenly Drops Considerably, It Must Be Moderated By Supplying Steam To Pre Heater.
Engines Provided With Mixing Column
1. It Can Be Done At Full Load Condition. 2. Keep Circulating Pump To Mixing Tank On. 3. Set Change Over To Diesel Oil. 4. Close Steam Supply To The Pre-heater.