Slagging And Its Prevention Analysis For Tangential Fired Utility Boilers

In view of the technical puzzle in the power plant-serious slagging during the combustion of bituminous pulverized coal in the boiler with four angle tangentical circle technology, velatively systematical experimental studies and theoretical analyses have been carried out on the mechanism of slagging, the influence of relevant conditions out of the boiler as well as the new technology for preventing slagging etc.Based on the obvious non—homogeneity of phenomenon about the temperature, velocity and smoke composition field in the boiler a new light to reduce slagging on the wall of boiler was put forward by enlarging the difference of the "three fields characteristics" of the zone between flame edge and the surface of water-colled wall from the central combustion zone, setting up the "near wall zone" with low temperature, low concentration of solid fuel, low burning rate and high oxygen amount. Furthermore, this light has technically come true by optimizating the stracture parameters of combustor and the operating parameters in the boiler.According to the above views, the combustor with combined-jet flows intersecting in the space of boilers to prevent slagging was advanced and studied. The unique flow field deduced by this combustor can establish a near wall zone with low temprature, low composition of solid fuel, low burning rate and high oxygen aomount which is beneficial to prevention of slagging. The reverse circulation flows in the near wall zone are of abvious effect on preventing fouling.In the light of the "zone character" and the "stage character" of thefouling in the boiler furnace, the traditional testing method by homgenitzing combustion parameters of furnace as a whole has been improved and the new testing method that the test operating is focused only in the small zone has been pased, with which the operating is in more targed way and the ability to predict the operating results is stronger. Both of them have been used in the industrial test techniques successfully.The experimental studies both under room temperrature and combustion condition on these two. technologies and the theoretical analyses on the mechanism of preventing fouling have been conducted.Y.K Dang (Thermal Science and Engineering) Directed by Professer Z.Y.Guo...