Approximately how many gallons of fuel oil are consumed per year given a load of 50,000 lb/hr, 8,400 hours/year, and a steam rate of 114 lb/gal?

• A. 3,500,000
• B. 3,600,000
• C. 3,800,000
• D. 3,684,000

Answer: (D)

Think in terms of how many gallons of fuel oil are needed to produce the given amount of steam. If the boiler produces 50,000 lb of steam per hour and one gallon of fuel oil yields 114 lb of steam, then the gallons of fuel per hour is 50,000 divided by 114, which is about 438.6 gal/hour. Multiply by the yearly operating hours: 438.6 × 8,400 ≈ 3,684,000 gallons per year. The precise calculation is 50,000/114 = 438.5965; times 8,400 gives about 3,684,210 gallons, which rounds to 3,684,000.