Problem
Find fuel required to generate 12,000 kg/h steam when enthalpy rise is 2,300 kJ/kg, fuel CV is 40,000 kJ/kg and boiler efficiency is 80%.
Given Data
Write all quantities in consistent SI units before substitution.
Formula and Solution
Heat to steam = 12,000 × 2,300 = 27,600,000 kJ/h. Fuel heat input = 27,600,000/0.80 = 34,500,000 kJ/h. Fuel = 34,500,000/40,000 = 862.5 kg/h.
Engineering Check
Check units, magnitude and physical meaning. State any simplifying assumptions and avoid mixing mass flow per hour with energy per second.
Practice Variation
Repeat the problem after changing one input by 10% and explain how the answer responds.