A fuel oil fired boiler's steam rate averages 114 lb of steam per gallon of fuel oil. The boiler operates 24 hr/day, 350 days/yr. The fuel cost is $0.58/gal and the load is 50,000 lb/hr. What is the annual fuel cost?

• A. $2,137,000/yr
• B. $2,136,000/yr
• C. $2,139,000/yr
• D. $2,150,000/yr

Answer: (A)

The amount of fuel needed is determined by how much steam you produce per gallon of fuel. If you need 50,000 lb of steam per hour and each gallon of fuel yields 114 lb of steam, you burn about 50,000 / 114 ≈ 438.6 gallons per hour.

The boiler runs 24 hours a day for 350 days a year, which is 24 × 350 = 8,400 hours annually. So annual fuel consumption is 438.6 gal/hr × 8,400 hr ≈ 3,684,210 gallons per year.

Multiplying by the fuel cost of $0.58 per gallon gives about 3,684,210 × 0.58 ≈ $2,136,842 per year, which rounds to roughly $2,137,000 per year.