Effect Of Interrupting Circulating Loop On Gas-solids Hydrodynamics In A Six-cyclone CFB Boiler Furnace

CFB boiler is a high efficient and clear coal combustion technology, and its steam parameters have advanced towards supercritical level. Although the uniform diffusion of feeding and feeding back directly related to temperature distribution, combustion efficiency and hydrodynamics in a multi-loop CFB boiler, few data on the effect of interrupting circulating loop on hydrodynamics are available in the published literature.In this paper, experimental research and numerical simulation are carried out on the in-furnace gas-solid hydrodynamics with interrupting circulating loop in a cold test-rig, which is based on the design scheme of600MW supercritical CFB boiler.The six-cyclone CFB cold test-rig is built according to the CFB scaling method. And it is scaled down from the Dongfang Boiler Company600MW supercritical CFB boiler. Research contents in this paper can be divided into three parts, including:①research on the effect of interrupting circulating loop on in-furnace hydrodynamics by experimental method;②research on the in-furnace hydrodynamics with interrupting circulating loop by numerical simulation method;③comparison of the experimental result and numerical simulation result.The experimental result shows that the suspension density decreases with time and will reach an equilibrium value after a certain time with interrupting circulating loop; once the solids recycle valve was reopened, the system would reach balance again as before; the solids are well-distributed along the horizontal direction with interrupting one circulating loop; interrupting two circulating loops on the same side and different operation parameters have an obvious influence on the concentration distribution;With the Fluent commercial software, the numerical simulation of in-furnace hydrodynamics is carried out by using two-fluid Model. Compared to the experimental result, the numerical simulation result presents a good fit. Moreover, the research in this paper provides a technical reference for the operation of six-cyclone supercritical CFB boiler.