Papers by Keyword: Aerodynamic Field

Abstract: A new over-fire air (OFA) program is proposed for Foster Wheeler (FW) type arch-fired boiler: the OFA nozzles are setting on arches near the furnace center and emitting OFA flow into the furnace at an inclined angle. Cold airflow experiments were conducted to determine the effect of the OFA velocity on the aerodynamic field in a small-scale furnace modeled for a 660-MWe arch-fired boiler. As the OFA velocity increases, the penetration depth of the OFA flow increases and the turning point of the OFA flow moves to the furnace center. At the same time, the vertical velocity of arch-injected airflow reduced faster because of the attracted effect of the OFA flow with higher velocity. When the OFA velocity is 22.39m/s (corresponding to 30m/s in the actual boiler), the OFA flow could penetrate to the furnace center and mix with the upflowing gas completely, while the arch-injected airflow have sufficient travel distance and enough residence time in the lower furnace. Thus, considering the penetration depth of arch-injected flow and the OFA flow, an OFA velocity of 22.39m/s recommended according to the present work.

Abstract: The characteristics of the WGZ170/9.8-3 pulverized coal boiler were obtained based on cold test，Including the air velocity distribution in tangential firing boiler and the relation between air distribution with opening of each secondary air dampe，The test results had determined that the baffle of blower at around 40% and two parallel draft fan about 45% were relatively appropriate. and the air distribution and opening of each secondary air dampe and balancing the distribution of primary air and second air along the width direction of the boiler hearth were confirmed through test，and the aerodynamic field inside the boiler was investigated based on the tie-floating test．and good aerodynamic field can be obtained after distributing the primary air and second air reasonably，which guarantee the ignition and stable operation of the boiler．