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 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 key idea is converting steam demand into fuel usage with the given steam-to-fuel ratio, then multiplying by operating time and fuel cost.

Fuel consumption per hour = steam load / steam per gallon

= 50,000 lb/hr ÷ 114 lb steam per gallon ≈ 438.60 gallons/hour.

Annual operating hours = 24 hours/day × 350 days/year = 8,400 hours/year.

Annual fuel gallons = 438.60 × 8,400 ≈ 3,684,210 gallons.

Annual fuel cost = 3,684,210 gallons × $0.58/gallon ≈ $2,136,842, which rounds to about $2,137,000 per year.