Question

The steam requirements of a manufacturing facility are being met by a boiler whose rated heat input is 5.5 x 3^106 Btu/h. The combustion efficiency of the boiler is measured to be 0.7 by a hand-held flue gas analyzer. After tuning up the boiler, the combustion efficiency rises to 0.8. The boiler operates 4200 hours a year intermittently. Taking the unit cost of energy to be $4.35/10^6 Btu, determine the annual energy and cost savings as a result of tuning up the boiler.

Answer 1

Energy Saved = 6.93 x 10⁹ Btu

Cost Saved = $ 30145.5

Step-by-step explanation:

The energy generated by each boiler can be given by the following formula:

`Annual\ Energy = (Heat\ In)(Combustion\ Efficiency)(Operating\ Hours)`

Now, the energy saved by the increase of efficiency through tuning will be the difference between the energy produced before and after tuning:

`Energy\ Saved = (Heat\ In)(Efficiency\ After\ Tune - Efficiency\ Before\ Tune)(Hours)`
`Energy\ Saved = (5.5\ x\ 3\ x\ 10^(6)\ Btu/h)(0.8-0.7)(4200\ h)`

Energy Saved = 6.93 x 10⁹ Btu

Now, for the saved cost:

`Cost\ Saved = (Energy\ Saved)(Unit\ Cost)\\Cost\ Saved = (6.93\ x\ 10^(9)\ Btu)(\$4.35/10^(6)Btu)\\`

Cost Saved = $ 30145.5