4 replies to this topic

[rabindra]

In my unit I have a process stream which is rejecting heat to the atmosphere through an air cooler from 164 Deg C to 100 Deg C. I was wondering if I can use this heat to preheat the Fuel Oil / Fuel Gas to furnace. Both the above utilities are received at the unit battery limit at ambient temperature. My question are:

 

1. Will there be any substantial benefit in increase in the fuel temperature?

2. Will it call for a modification in the burners?

 

Any other things I should consider before implementing the same?

 

thanks

[PingPong]

How much fuel flow are we talking about here? Probably the amount of heat it can take up is not worth mentioning.

It makes much more sense to preheat the combustion air to the heater.

[rabindra]

We are already preheating the combustion air. I will revert on the fuel flow and available heat.

[rahulavyas]

1. Generally fuel gas is not heated
2. Heating Fuel Oil will make sense as you can maintain correct viscosity at the burner tip when you heat, generally if you are using “Fuel oil/ LSHS” temperature of about 120°C is maintained (Check the liquid fuel being used and viscosity needed to be maintain).
3. Word of caution – here you are talking about heat exchange between a clean process fluid and fuel oil (dirty service) check the consequences in case on exchanger leak. Please do carry out a detail PHA for this.

[JMW]

If you have available heat for fuel oil heating, then it means that if you are to maintain the optimum viscosity of the fuel you can consider using a heavier grade of fuel oil. However, this may require a great deal more investment in heat exchangers etc.

It will only make sense if the fuel oil is being heated using heat that is not already recovered from the combustion process via steam raising for example. I would suspetc that the combustion process already generates enough excess heat for this purpose.