Investigation of flow inside pulverized coal (PC) pipes against coal particle size and air flow rate for a utility boiler

Abstract

This study mainly focuses on investigation on effect coal particle size on flow inside pulverized coal pipes for a utility boiler. The flow that is analyzed here will be the wall shear stress. The objective of the study is to determine the effect of coal particle size and effect of air flow rate on the wall shear stress of pulverized coal pipes. The individual wall shear stress which is computed as area weighted average of the pulverized coal pipes that is studied is compared and analyzed. There are total of 28 pulverized coal pipes in the power plant that is chosen as case study. The study is divided into two parts mainly the effect of coal particle size on the wall shear stress and the other is effect of air flow rate on the wall shear stress. In both configurations the wall shear stress is computed as area weighted average. Prior to simulation the file that is used to study the wall shear stress is modified using Gambit to improve results. The individual wall shear stress of all pipes coming out of a particular mill is observed after contours are developed using CFD tool like Ansys fluent. Parameters like coal flow rate and coal velocity are set in the simulation and results are generated Based on contours and developed graph from the simulation, the effect of both configuration is studied and the range of particle size and range of air flow rate which is suitable for the optimum operation of boiler is suggested.