How can a Boiler Tune Up Improve Efficiency and Save on Costs?

[Adam Bourque]

Homework Statement

BTU input: 2.5 MMBtu/hr
Annual Gas usage: 8,525 MMBtu
Average Natural Gas Cost (Previous 12 months): $7.59/MMBtu
Manufacturing Plant – 7am-7pm, 7 days/week, 50 weeks/yr
Assembly/warehouse - 7:00am-10:00pm, 7 days/week, 363 days/yr
The gas analyzer was used to check the O2 and temperature of the boiler exhaust during the on-site visit. The O2 level was found to be 10% and the exhaust temperature rise was 510°F.
a.) How would you go about doing a Boiler Tune up for the following system? Be specific to what values and specifications you alter.
b.) What is the cost savings from improving the efficiency.

Homework Equations

a.)[/B]

b.)
ΔFuel Used = (new - old / new) (Old Fuel Used)

The Attempt at a Solution

a.) My recommendation is to lower the O2 level to 2% and lower the exhaust temperature rise to 87.5 to create an efficiency of 87.8% from the existing 81%. Is this possible and if so, does my readings seem right? I used the graph below. Also, is there anything else we can do to make it more efficient such as a different BTU input?
b.) (50 weeks * 7 days * 12 hours) = 4200 hours, & $7.59 MMBtu / 1.032 MCF = $7.35 per MCF
(64,704.75 Cost Year) / (4200hrs)($7.35) = 2.0960 MCF per hour
Fuel Used = (87.8 - 81 / 87.8) (2.0960) = .162332 MCF per hour
Savings = (.162332/hr)(4200 hrs/year)(7.35/MCF) = $5011/yr

I know this is a good bit of info in one problem, so I really do appreciate any feedback on this. Thanks so much.

 

[Adam Bourque]

bring up my post