Products
Rewards
from HOLOOLY

We are determined to provide the latest solutions related to all subjects FREE of charge!

Enjoy Limited offers, deals & Discounts by signing up to Holooly Rewards Program

HOLOOLY

HOLOOLY
TABLES

All the data tables that you may search for.

HOLOOLY
ARABIA

For Arabic Users, find a teacher/tutor in your City or country in the Middle East.

HOLOOLY
TEXTBOOKS

Find the Source, Textbook, Solution Manual that you are looking for in 1 click.

HOLOOLY
HELP DESK

Need Help? We got you covered.

## Q. 8.2

The boiler of Example 8.1 uses 1,500,000 L of fuel oil per year. An instrumentation kit is purchased at a cost of $20,000 and is used to adjust the boiler operation so its excess of $O_{2}$ is only 3 percent. Determine the payback of the instrumentation if the cost of fuel oil is$0.20/L.

## Verified Solution

From Example 8.1, the existing boiler has excess $O_{2}$ of 6 percent and an overall boiler thermal efficiency of about 78 percent (i.e., $η_{std}$ = 0.78 ).

After the boiler tune-up, the excess $O_{2}$is 3 percent. Using the monograph of Figure 8.1, the new boiler efficiency can be determined from the flue gas temperature (343°C or 650°F) and the excess $O_{2}$(3 percent). It is found to be $η_{eff}$ = 84% = 0.84 . Using Eq. (8.4), the fuel savings can be calculated:

$ΔFU=\frac {η_{eff}-η_{std}}{η_{eff}}.FU_{std}$             (8.4)

$ΔFU=\frac {0.84-0.78}{0.84}, 1,500,000=107,104L/yr$

Therefore, the simple payback period for the instrumentation is:

$SBP=\frac{\20,000}{107,104L/yr *\0.20/L}=1.0 year$