... Classic Solutions for Combustion Control ... Control by " Simple Cross Limits " and Control by " Double Limits Cross ".

1. Combustion Control for Petrochemical Furnace
Furnace
Air Combustion
Fuel
Combustion Control Panel
&
Safety System Panel

2. Combustion Control by Cross Limits

3. Combustion Control by Cross Limits
Air Fuel Ratio calculation:
- FLOWAIR = FLOWSTOICHIOMETRIC AIR + FLOWAIR EXCESS
- AFR = FLOWAIR / FLOWFUEL => FLOWAIR = AFR x FLOWFUEL
=> FLOWFUEL = FLOWAIR / AFR
Equilibrium Condition => When SP of Combustion Air is Equal SP of Fuel;
Increase Load => First it increase SP of Combustion Air, after confirmation it by Flow
Transmitter, it increase SP of Fuel; " Safety Condition “
Decrease Load => First it decreases SP of Fuel, after confirmation it by Flow Transmitter, it
decreases SP of Combustion Air. " Safety Condition “
FLOWAIR FLOWFUELLOAD
FLOWFUEL FLOWAIRLOAD

4. Combustion Control by Double Cross Limits

5. Combustion Control by Double Cross Limits
Air Fuel Ratio calculation:
- FLOWAIR = FLOWSTOICHIOMETRIC AIR + FLOWAIR EXCESS
- AFR = FLOWAIR / FLOWFUEL => FLOWAIR = AFR x FLOWFUEL
=> FLOWFUEL = FLOWAIR / AFR
Equilibrium Condition => SP of Combustion Air is Equal SP of Fuel;
Increase Load => It increase SP Combustion Air and SP Fuel at the same time, but it is made
between Low Limit and High Limit for ensure the operation condition.
... Safety condition: The measured AFR must not be
too different than the adjusted AFR ...
Decrease Load => It decrease SP Combustion Air and SP Fuel at the same time, but it is made
between Low Limit and High Limit for ensure the operation condition.
... Safety condition: The measured AFR must not be
too different than the adjusted AFR ...
FLOWAIR FLOWFUELLOAD
FLOWAIR FLOWFUELLOAD