Which expression correctly represents the annual fuel cost FC given the steam load, operating hours, price, and steam rate?

Which expression correctly represents the annual fuel cost FC given the steam load, operating hours, price, and steam rate?

• A. FC = (SL x 24 x 350 x P) / SR
• B. FC = (SR x P) / (SL x 24)
• C. FC = SL x P x SR x 24 x 350
• D. FC = (SL x P) / (SR x 24)

Answer: (A)

Think of FC as the yearly fuel bill needed to generate the steam you require. You start with how much steam you produce each hour (the steam load), then figure out how many hours the plant runs in a year, convert that to total steam produced in a year, translate that steam into fuel consumed using the steam rate, and finally multiply by the fuel price. So you multiply the steam load by the annual operating hours: 24 hours per day times 350 days per year, giving the total pounds of steam produced in a year. To convert that to fuel, divide by the steam rate (how many pounds of steam you get per pound of fuel), which yields the pounds of fuel used in the year. Multiply by the price per pound of fuel to obtain the annual cost. This gives FC = (SL × 24 × 350 × P) / SR. This expresses the intuitive relationships: more steam or a higher price increases cost, while a higher steam rate (better fuel efficiency) reduces cost. For a quick check, using numbers as an example shows the calculation steps align with the same result.

Think of FC as the yearly fuel bill needed to generate the steam you require. You start with how much steam you produce each hour (the steam load), then figure out how many hours the plant runs in a year, convert that to total steam produced in a year, translate that steam into fuel consumed using the steam rate, and finally multiply by the fuel price.

So you multiply the steam load by the annual operating hours: 24 hours per day times 350 days per year, giving the total pounds of steam produced in a year. To convert that to fuel, divide by the steam rate (how many pounds of steam you get per pound of fuel), which yields the pounds of fuel used in the year. Multiply by the price per pound of fuel to obtain the annual cost. This gives FC = (SL × 24 × 350 × P) / SR.

This expresses the intuitive relationships: more steam or a higher price increases cost, while a higher steam rate (better fuel efficiency) reduces cost. For a quick check, using numbers as an example shows the calculation steps align with the same result.