The NOx emissions of a 40,000 BTU/hr (11.7kW) natural gas water heater are studied at different primary equivalence ratios (Φ). CO emission, O2 content in the flue gas and other related parameters are measured to assess the potential for NOx emission reductions with relatively modest changes in current burner and combustion chamber designs. In addition, N2 is introduced into the primary fuel and air flow to simulate flue gas recirculation (FGR) in order to estimate what benefit such a strategy might provide. NOx concentration in the exhaust decreases from 84 ppm to 34 ppm (at 3% dry O2) when the primary equivalence ratio is decreased from 4.8 to 1.3. The flame structure also varies with primary equivalence ratio. When Φ is lower than 2.1, the flame starts to show a highly unsteady structure, and NOx emissions fluctuate at this range of Φ. However, the observed NOx emissions decrease with a decreasing Φ indicates a potential method of significant NOx reduction in natural gas water heaters if the flame could be stabilized. Introducing 10 standard liters per minute (SLPM) N2 (15% of the primary air at Φ = 3) into the primary fuel and air flow further decreases NOx emission levels by 20% to 29%, which indicates that flue gas recirculation (FGR) may be a viable method of reducing NOx of natural gas water heaters using on pancake burners.
|Commitee:||Borg, John, Bowman, Anthony|
|School Location:||United States -- Wisconsin|
|Source:||MAI 51/04M(E), Masters Abstracts International|
|Keywords:||Combustion, Flue gas recirculation, Natural gas water heater, Nox emission, Pancake burner, Primary equivalence ratio|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be