Analysis and Treatment of Inaccurate Measurement of Primary Air Volume of Coal Mill
There was encountered by a 1000 MW unit of an actual plant the problem of inaccurate measurement of coal mill's primary air volume.The present work carried out causal analysis using air flow measuring principle and determined the root of the problem as uneven velocity distribution.Then it numerically simulated the pre-inlet primary air duct and established standard k-εturbulence model.It was found from calculation results that the data of measurement points can represent the entire measurement cross-section,which means there is no data deviation.The measuring tubes at positive and negative pressure sides provided by the manufacturer did not correspond to each other,with only three negative pres-sure sides,resulting in a significant error with average value of the measured cross-sectional velocity.After replacing new measuring tubes,accurate on-site air volume was achieved.
coal millprimary air ductair volume measurementnumerical simulation