Evaluation of Noise and Vibration in Boilers at High Loads

Abstract

Various components inside the boiler are required to promote efficient combustion and heat transfer. Their design depends on factors such as the type of fuel and the method selected to transfer thermal energy. The maximum power output from any thermal power plant is top priority for engineers, and maximum power output means maximum loads which related to maximum fuel consumption and air flow control system (A/F ratio). Vibration and noises resulted from the over dose of air –fuel ratio in boilers is the main consideration of this research project. The demands for electricity in peak-loads generate an unacceptable noise and vibration. This research tries to find a solution for noise and vibration in the boilers when operate on high load with high efficiency and safe mode for tools and operators. Physical measurement of the vibrations in the boilers by measuring probes is difficult in the running boiler due to high temperature. So, there is a need to evaluate vibrations in affected regions theoretically. Computational Fluid Dynamics (CFD) tools have been found appropriate to perform the flow analysis. Owing to recent improvements in CFD and by analysis the type of air flow in the boilers component of air duct, wind-box and burners we found the flow induced is the source of the noise and vibration, to reduce the effect of flow induce inside the boiler system we used CFD modeling and by partition of the duct of the inlet air for boiler number 5 by sheet metal and run ANSYS software before and after partition the flow dramatically change after partition, then the solution install in boiler number 5 therefore the problem was totally solve and the boiler operate with standard levels of noise and vibration. The recommendation is to implement the same solution of partition in boiler 3 &4 when the system is ready for installation of partition in the wind-box before burners the flow induce will be eliminated and the boiler will operate on the high load without noise and vibration.