Design Of Experimental Rig For 600MW CFB Coal Feeding And Study On Diffusion Theory

As a clean coal technology,the circulating fluidized bed combustion has been widely used around the world. Improving the steam parameters can lead to the improvement of power plant efficiency. So, a new research direction on combination of large-scale units and fluidized bed technology has been developed. However, in the process of development on large-scale units, there are many problems on designing the large-scale boiler. The uniformity of coal feeding is a major factor on designing the CFB boiler. Which affects the boiler efficiency, temperature distribution and equipment safety. This paper will make the research on the uniformity of 600MW CFBB, including following several aspects.At first, in order to build an experiment device, similarity criterions will be deduced under the background of similarity principle. Those criterions are deduced based on mass conservation equation, momentum conservation equation, Ergun equation and terminal conditions. Then, according to the criterion, the parameters of similarity principles will be selected. Ultimately, the parameters of experiment device can be decided and built.Secondly, heated particles will be used as tracing particles. Through theoretical analysis and conclusions, the feasibility of using heated particles as tracing particles is determined. It is concluded that under some conditions, the temperature rise in the unit infinitesimal which is brought about by the diffusing of heated particles is directly proportional to the concentration of tracing particles. Then the temperature rise can be measured to replace measuring the concentration of tracing particles.Thirdly, research on the concentration of tracing particles was carried out from the Fick law and the general diffusing conditions. And ignoring the minor conditions, a model of diffusing of this experiment was built up.Finally, the experiments were carried out on the device, including the calibration of coal feeding rate, the pressure drop of air distribution plate and bed materials.