DE-13-034 — Assessing the Causes of Combustion Drien Oscillations in Boilers using a Feedback Loop Stability Model (RP-1517)

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This paper is based on findings resulting from ASHRAE Research Project RP-1517.

Combustion-driven oscillations are a common problem with boilers, water heaters, and furnaces. Sound is produced by the flame and is reflected downstream from the combustion chamber. The reflected sound waves disturb the mixture flow or equivalence ratio, increasing the heat-release pulsations and the accompanying sound produced by the flame. This phenomenon has been described using a positive feedbackloop in prior work. The current paper applies the feedbackloop stability model to two boilers, which exhibited combustion oscillations. Additionally, a feedback loop model was developed for equivalence ratio fluctuations and validated. For the first boiler, the combustion oscillation problem was likely related to the geometry of the burner and the intake system, though results are inconclusive. For the second boiler, the model indicated that the combustion oscillations were due to equivalence ratio fluctuations. Accordingly, the combustion oscillations could be alleviated by changing the geometry of the intake system.

Product Details

Published:

2013

Number of Pages:

11

File Size:

1 file , 2.3 MB

Product Code(s):

D-DE-13-034

Note:

This product is unavailable in Russia, Belarus