This revision keeps a connected burner, chamber and flue topology while limiting the calculator to declared combustion-air mass-flow bookkeeping.
Declared Furnace Air-Flow Worksheet
Enter fuel mass rate, a declared stoichiometric air requirement and a declared excess-air percentage. The worksheet reports only the resulting mass-flow identities.
Equation Used
- Fuel and air mass rates use kg/h and the declared stoichiometric requirement uses kg air per kg fuel.
- Excess air is defined relative to the declared stoichiometric air mass.
- Lambda is actual declared air divided by declared stoichiometric air.
- The connected furnace drawing is qualitative and does not scale flame or gas properties.
- Flue oxygen, combustion completeness, temperature, emissions, efficiency, burner settings, equipment sizing and safety are excluded.
Removes the fuel-independent flue-O2 shortcut and fabricated penalty; outputs are only declared mass-flow identities.
Burner, chamber and flue form one connected path
An oil-fired furnace brings atomized fuel and combustion air together at a burner, contains the flame in a chamber, transfers heat to the surrounding process or boiler surfaces, and routes products toward a flue. DOE notes that oil combustion depends on atomization and pressure conditions.
The animation preserves this topology but does not simulate combustion, flame size, gas composition, heat transfer or controls.
A mass-flow identity, not a furnace design
EPA AP-42 documents distillate and residual oil combustion across stationary sources and shows that emissions and combustion controls depend on the equipment and operating conditions. This worksheet does not select equipment or prescribe settings.
Declared stoichiometric and excess-air bookkeeping
DOE defines excess air as air introduced relative to the theoretical stoichiometric amount. Here both the fuel's stoichiometric requirement AFRs and excess-air percentage EA are explicit user inputs.
The resulting lambda equals mair/mstoich, and excess-air mass is mair minus mstoich. These identities do not predict flue oxygen or combustion quality.
A declared mass-flow example
For 1.0 kg/h fuel, a declared stoichiometric requirement of 14.4 kg air/kg fuel gives 14.4 kg/h stoichiometric air. With 15% declared excess air, lambda is 1.15, actual declared air is 16.56 kg/h and the excess-air portion is 2.16 kg/h.
Real tuning requires measurements
DOE says the correct amount of excess air is determined from flue-gas oxygen or carbon-dioxide analysis. Too little or too much air can have different consequences, but no universal penalty follows from EA alone.
The former flue-O2 shortcut, clean-band penalty, efficiency ranges, operating settings, repair instructions, safety claims and fabricated sugar-refinery example are removed.
Petroleum-furnace worksheet questions
Does declared excess air set a safe operating point?
No.
Can the worksheet calculate flue oxygen?
No. Fuel chemistry, combustion completeness, moisture and measurement basis are omitted.
Does lambda predict efficiency or emissions?
No.
Can it tune or diagnose a furnace?
No. Follow the equipment manufacturer and qualified combustion-testing procedures.
Petroleum-furnace references
- US DOE CIBO Energy Efficiency Handbook: oil atomization and pressure-condition cautions.
- US DOE Steam System Survey Guide: definition of excess air relative to stoichiometric air.
- US DOE Steam Tip Sheet 4: real excess-air evaluation by flue-gas analysis.
- US EPA AP-42 Section 1.3: fuel-oil combustion sources and equipment-specific controls.
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