Supplemental fuel required calculator

The supplemental fuel supplies the useful-energy deficit.

Units

M_{\text{needed}} = \frac{Q_{\text{demand}} - Q_{\text{waste useful}}}{2000 \times \mathrm{HV} \times \eta}

Calculator

Enter the values you know and leave one box empty. Calculate finds the empty one, the result or any input.

Given

M_{\text{needed}} = \frac{60{,}000{,}000{,}000 - 20{,}000{,}000{,}000}{2000 \times 12{,}000 \times 0.82} \approx 2{,}033

Symbol	Meaning	Unit
$M_{\text{needed}}$	supplemental fuel mass	short ton/yr
$Q_{\text{waste useful}}$	usable waste-fuel heat	Btu/yr
$Q_{\text{demand}}$	annual useful heat needed	Btu/yr
$\mathrm{HV}$	supplemental fuel heating value	Btu/lb
$\eta$	supplemental boiler efficiency	—

Symbol	Meaning	Unit
$M_{\text{needed}}$	supplemental fuel mass	kg/year
$Q_{\text{waste useful}}$	usable waste-fuel heat	GJ/year
$Q_{\text{demand}}$	annual useful heat needed	GJ/year
$\mathrm{HV}$	supplemental fuel heating value	kJ/kg
$\eta$	supplemental boiler efficiency	—

Results are estimates for study and screening. Check the inputs, units and assumptions before you use them for design, billing or contract decisions.