Noise Analysis and Reduction of High-Intensity Combustors for Domestic Use.

Abstract

Noise analyses using sound intensity and other parameters were carried out for the purpose of reducing the noise which increases with the high-intensity combustion of domestic water heaters, and the quantification of sound sources and the propagation path of noise was carried out. Furthermore, based on the results of these analyses combustion noise, which is the main part of low frequency was, examined, and it was clarified that the compatibility of load increase and noise reduction can be attained by properly combining the primary air ratio and secondary air ratio, where in the case of the primary air ratio being constant, the secondary air ratio exerts am influence on the intensity of noise by the second to the fourth power. Additionally, it was shown that the dominant sound emitted during combustion is the pipe resonance where one end is closed and the other end is open, and the effective method of reducing dominant sound was shown.